Beidou2020
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China already has very advanced technology in many areas. Forget what the haters say, China is on the rise.
China Science & Technology Forum
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Topology of H-Bonded Networks at Water/Solid Interfaces Could be Determined with Atomic Precision
Published on January 10, 2014 at 4:02 AM
The interaction of water with the surfaces of solid materials is ubiquitous. Many remarkable physical and chemical properties of water/solid interfaces are governed by H-bonding interaction between water molecules. As a result, the accurate description of H-bonding configuration and directionality is one of the most important fundamental issues in water science.
Ideally, attacking this problem requires the access to the internal degrees of freedom of water molecules, i.e. the O-H directionality. However, resolving the internal structure of water has not been possible so far despite massive efforts in the last decades due to the light mass and small size of hydrogen.
(a) 3D STM topographic image of water monomers and tetramers adsorbed on the NaCl(001) surface. (b) and (c) HOMO and LUMO images of a water monomer, respectively. (d) and (e) HOMO images of two water tetramers with different H-bonding chirality. (f)-(i) Calculated isosurfaces of HOMO and LUMO orbitals, corresponding to (b)-(e).
Recently, the teams led by Professor Ying Jiang and Professor Enge Wang of International Center for Quantum Materials (ICQM) of Peking University succeeded to achieve submolecular-resolution imaging of individual water monomers and tetramers adsorbed on a Au-supported NaCl(001) film at 5 K, using a cryogenic scanning tunneling microscope (STM). They first decoupled electronically the water molecule from the metal substrate by inserting an insulating NaCl layer and then employed the STM tip as a top gate to tune controllably the molecular density of states of water around the Fermi level. These key steps enabled them to image the frontier molecular orbitals which are spatially locked together with the geometric structures of water molecules. Notably, they were able to discriminate in real space the orientation of water monomers and the H-bonding directionality of water tetramers based on the submolecular-resolution orbital images.
This work opens up the possibility of determining the detailed topology of H-bonded networks at water/solid interfaces with atomic precision, which is only possible through theoretical simulations in the past. The ability to resolve the O-H directionality of water provides further opportunities for probing the dynamics of H-bonded networks at atomic scale such as H-atom transfer and bond rearrangement. In addition, the novel orbital-imaging technique developed in this work reveals new understanding of STM experiments and may be applicable to a broad range of molecular systems and materials.
This work was published online in Nature Materials on Jan. 5, 2014 [Nature Materials DOI: 10.1038/nmat3848, http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat3848.html]. This work received supports from Ministry of Science and Technology of China, National Natural Science Foundation of China, Ministry of Education of China, and Peking University.
Topology of H-Bonded Networks at Water/Solid Interfaces Could be Determined with Atomic Precision
Published on January 10, 2014 at 4:02 AM
The interaction of water with the surfaces of solid materials is ubiquitous. Many remarkable physical and chemical properties of water/solid interfaces are governed by H-bonding interaction between water molecules. As a result, the accurate description of H-bonding configuration and directionality is one of the most important fundamental issues in water science.
Ideally, attacking this problem requires the access to the internal degrees of freedom of water molecules, i.e. the O-H directionality. However, resolving the internal structure of water has not been possible so far despite massive efforts in the last decades due to the light mass and small size of hydrogen.
(a) 3D STM topographic image of water monomers and tetramers adsorbed on the NaCl(001) surface. (b) and (c) HOMO and LUMO images of a water monomer, respectively. (d) and (e) HOMO images of two water tetramers with different H-bonding chirality. (f)-(i) Calculated isosurfaces of HOMO and LUMO orbitals, corresponding to (b)-(e).
Recently, the teams led by Professor Ying Jiang and Professor Enge Wang of International Center for Quantum Materials (ICQM) of Peking University succeeded to achieve submolecular-resolution imaging of individual water monomers and tetramers adsorbed on a Au-supported NaCl(001) film at 5 K, using a cryogenic scanning tunneling microscope (STM). They first decoupled electronically the water molecule from the metal substrate by inserting an insulating NaCl layer and then employed the STM tip as a top gate to tune controllably the molecular density of states of water around the Fermi level. These key steps enabled them to image the frontier molecular orbitals which are spatially locked together with the geometric structures of water molecules. Notably, they were able to discriminate in real space the orientation of water monomers and the H-bonding directionality of water tetramers based on the submolecular-resolution orbital images.
This work opens up the possibility of determining the detailed topology of H-bonded networks at water/solid interfaces with atomic precision, which is only possible through theoretical simulations in the past. The ability to resolve the O-H directionality of water provides further opportunities for probing the dynamics of H-bonded networks at atomic scale such as H-atom transfer and bond rearrangement. In addition, the novel orbital-imaging technique developed in this work reveals new understanding of STM experiments and may be applicable to a broad range of molecular systems and materials.
This work was published online in Nature Materials on Jan. 5, 2014 [Nature Materials DOI: 10.1038/nmat3848, http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat3848.html]. This work received supports from Ministry of Science and Technology of China, National Natural Science Foundation of China, Ministry of Education of China, and Peking University.
Topology of H-Bonded Networks at Water/Solid Interfaces Could be Determined with Atomic Precision
shuttler
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^^ great finding!
While in a previously reported scientific finding we have done the following (post # 279).
We have shown taking steps forward in the mastery of capturing visual images of some ultra minute phenomena using various AFM and STM means. Though it seems far-fetched to talk about it so soon, these findings are important for researchers to advance to more in-depth studies of molecular/atomic structures of complex material, diseases and the manipulation of which can lead to generation of new materials or to combat some prevalent deadly diseases
While in a previously reported scientific finding we have done the following (post # 279).
We have shown taking steps forward in the mastery of capturing visual images of some ultra minute phenomena using various AFM and STM means. Though it seems far-fetched to talk about it so soon, these findings are important for researchers to advance to more in-depth studies of molecular/atomic structures of complex material, diseases and the manipulation of which can lead to generation of new materials or to combat some prevalent deadly diseases
Researchers create image of weak hydrogen bond using AFM
Oct 01, 2013 by Bob Yirka
AFM measurements of 8-hq assembled clusters on Cu(111). (A and B) Constant-height frequency shift images of typical molecule assembled clusters, and their corresponding structure models (C and D). Imaging parameters: V = 0 V, A = 100 p.m., Δz …more
(Phys.org) —Researchers at China's National Center for Nanoscience and Technology and Renmin University have used Atomic Force Microscopy (AFM) to create an image of the weak hydrogen bonds present in a molecule. In their paper published in the journal Science, the team describes how they used the non-contact form of AFM to capture an image of weak hydrogen bonds in a 8-hydroxyquinoline molecule (8hq).
Until recently, the most accurate images of molecules were obtained using scanning tunneling microscopy, recent advances with AFM, however (particularly the addition of a carbon monoxide molecule to the probe tip) have made it the method of choice for obtaining actual images of molecules and the bonds that hold them together. In this new effort, the research team has advanced the science of AFM by capturing an image of the weak hydrogen bonds present in a 8hq molecule. Understanding how hydrogen bonds work is a very important part of science—they are responsible, for example, for holding together strands of DNA.
Currently, there are two ways to capture images using AFM: contact, and non-contact imaging. With contact imaging, the tip of the mechanical probe is made to touch the surface of the material being analyzed. The amount of deflection of the probe tip as its dragged is used to create an image. In non-contact mode, the tip is brought near to the surface, but doesn't touch it. An image is created by measuring changes to the oscillating tip probe from weak forces emanating from the source.
The team in China used the non-contact form of AFM and chose 8hq as a test subject because it's a relatively flat molecule. The resulting image is the first created using AFM to show weak hydrogen bonds, and is important because there is still debate about the nature of hydrogen bonds. For many years it was considered to be purely an electrostatic interaction—new evidence has cast doubt on that idea, suggesting that it might be at least partially chemical. The new image doesn't clear up the debate, but does offer some intriguing possibilities for the future as it demonstrates that as AFM matures, it will offer more and more evidence of the true nature of molecules and how they interact.
ABSTRACT
We report a real-space visualization of the formation of hydrogen bonding in 8-hydroxyquiline (8-hq) molecular assemblies on a Cu(111) substrate using noncontact atomic force microscopy (NC-AFM). The atomically resolved molecular structures enable a precise determination of the characteristics of hydrogen bonding networks, including the bonding sites, orientations, and lengths. The observation of bond contrast was interpreted by ab initio density functional calculations, which indicated the electron density contribution from the hybridized electronic state of the hydrogen bond. Intermolecular coordination between the dehydrogenated 8-hq and Cu adatoms was also revealed by the submolecular resolution AFM characterization. The direct identification of local bonding configurations by NC-AFM would facilitate detailed investigations of intermolecular interactions in complex molecules with multiple active sites.
Read more at: Researchers create image of weak hydrogen bond using AFM
The report in Science here the link:
Real-Space Identification of Intermolecular Bonding with Atomic Force Microscopy
-Author and Affiliations:
Jun Zhang-1,*, Pengcheng Chen-1,*, Bingkai Yuan-1, Wei Ji-2,†, Zhihai Cheng-1,†, Xiaohui Qiu-1,†
- Key Laboratory of Standardization and Measurement for Nanotechnology, Chinese Academy of Sciences, National Center for Nanoscience and Technology, Beijing 100190, China.
- Department of Physics, Renmin University of China, Beijing 100872, China.
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cirr
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China unveils native mobile operating system
English.news.cn 2014-01-09 19:37:38
BEIJING, Jan. 9 (Xinhua) -- A new mobile phone operating system was unveiled by a Chinese tech firm on Thursday, making it the country's first smart phone system with independent intellectual property rights.
The system, named 960 OS, was developed by the Coship Electronics Co., Ltd. It is a brand new operating system following predecessors such as Android, IOS, and Windows phone, the Shenzhen-based company said.
960 OS is a native operating system based on the Linux kernel and took Coship 15 years to develop, said the company's chair, Yuan Ming, noting that the system can provide better protection for information stored in a smart phone.
As the majority of smartphones in the Chinese market use foreign operating systems such as Android and IOS, the ownership of one system with independent IPR is essential for both national and individual information security, according to Liu Yunjie, an academician of the Chinese Academy of Engineering.
It can boost the competitiveness of China's mobile and Internet industry, he added.
China unveils native mobile operating system - Xinhua | English.news.cn
COS（China Operating System）announced on 15.01.2014：
中科院发布自主知识产权操作系统 中移动中电信已测试 - 要闻\新闻 — C114(中国通信网)
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cirr
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China's top quantum tech center founded in Hefei
2014-01-16 09:06chinadaily.com.cnWeb Editor: Wang Fanhttp://www.ecns.cn/2014/01-16/97201.shtml#comment
The CAS Center for Excellence Quantum Information and Quantum Physics（place where China's first practical quantum computer is likely to be born？） was founded in Hefei, Anhui province, on Wednesday.
The center, based in the University of Science and Technology of China and under the leadership of the Chinese Academy of Sciences, will be built into a top-notch academic institution with an international influence in quantum information and quantum physics, Bai Chunli, president of CAS, said at the founding ceremony.
Earlier this year, the CAS launched a program establishing five top innovation centers in China in wake of President Xi Jinping's call to deepen reform and innovation in science and technology to enhance the nation's strength.
The CAS aims to build the Hefei-based center into a model for the other four centers, specializing in the earth system science of Qinghai-Tibet plateau, particle physics, brain science and thorium molten salt reactors, according to the CAS president.
China's top quantum tech center founded in Hefei - Headlines, features, photo and videos from ecns.cn|china|news|chinanews|ecns|cns
2014-01-16 09:06chinadaily.com.cnWeb Editor: Wang Fanhttp://www.ecns.cn/2014/01-16/97201.shtml#comment
The CAS Center for Excellence Quantum Information and Quantum Physics（place where China's first practical quantum computer is likely to be born？） was founded in Hefei, Anhui province, on Wednesday.
The center, based in the University of Science and Technology of China and under the leadership of the Chinese Academy of Sciences, will be built into a top-notch academic institution with an international influence in quantum information and quantum physics, Bai Chunli, president of CAS, said at the founding ceremony.
Earlier this year, the CAS launched a program establishing five top innovation centers in China in wake of President Xi Jinping's call to deepen reform and innovation in science and technology to enhance the nation's strength.
The CAS aims to build the Hefei-based center into a model for the other four centers, specializing in the earth system science of Qinghai-Tibet plateau, particle physics, brain science and thorium molten salt reactors, according to the CAS president.
China's top quantum tech center founded in Hefei - Headlines, features, photo and videos from ecns.cn|china|news|chinanews|ecns|cns
shuttler
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Announcement of the successful clinical trial of China's "pace-makers" for brain disease patients ( incl. Parkinson's disease)
Congratulations to the Tsinghua University researchers!
The video reporting here:
中国国产脑起搏器打破美国独家技术垄断-20131210新闻联播-凤凰视频-最具媒体品质的综合视频门户-凤凰网
Congratulations to the Tsinghua University researchers!
The video reporting here:
中国国产脑起搏器打破美国独家技术垄断-20131210新闻联播-凤凰视频-最具媒体品质的综合视频门户-凤凰网
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shuttler
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'Waterjet' printer set to make a splash
29 January 2014 Tim Wogan
The use of different aromatic dyes that isomerise when wet have been used to create paper that can be printed on again and again © NPG
Many people are keen to reduce their paper waste, but storing and sharing data electronically is not always feasible. Rewritable paper would be one answer to this problem. Now, Chinese scientists have come up with
‘waterjet printing’ that uses paper coated with dyes that change colour when wet and return to their colourless state when dry.
To create rewritable paper the researchers screened various organic compounds and picked four oxazolidines. The lower-energy closed ring isomers of these oxazolidines are colourless in the absence of water. But when the paper is wetted hydrogen bonding stabilises the more polar open ring form of the molecules, changing the dyes’ absorption of visible light. The exact wavelengths absorbed vary with the organic compound used, allowing the researchers to print in a variety of colours.
The rewriteable paper was made by first coating ordinary paper with a layer of polyethylene glycol (PEG) to prevent it reacting with the dye, before a second layer of PEG containing the chosen dye was laid on top. Finally, another layer of PEG was added to prevent the dye absorbing water from the air or, conversely, losing water too quickly.
The team used a commercial inkjet printer and a cartridge filled with water to print out their own Nature Communicationspaper on the dyes. The printed page is dry to the touch and the print can be rapidly ‘erased’ by heating it to 70°C. Under ambient conditions the print remained legible for around 22 hours before evaporation wiped the page clean. Paper prepared in this way can be printed on and then erased more than 50 times.
The researchers are now working to extend the print’s lifetime, but principal investigator Xiao-An Zhang of Jilin University says swift fading would have advantages for daily newspapers, for example. ‘After people had finished, they could put the paper back and the colour would disappear,’ he says. ‘Every morning you'd have a fresh issue.’ He suggests different papers could be manufactured on which printouts would last for different lengths of time. The team is also currently working towards multi-colour printouts. Zhang declines to give details but says ‘we have confidence that eventually we will deliver them’.
Organic photochemist Francisco Raymo of the University of Miami, US, who helped develop the dye molecules but was not involved in the latest research, says he was ‘very pleased to see that our molecules are being put to good use’. However, he suspects the idea's commercial prospects may be hampered by the need to specially prepare the paper with a multi-layer coating.
Link:
'Waterjet' printer set to make a splash | Chemistry World
29 January 2014 Tim Wogan
The use of different aromatic dyes that isomerise when wet have been used to create paper that can be printed on again and again © NPG
Many people are keen to reduce their paper waste, but storing and sharing data electronically is not always feasible. Rewritable paper would be one answer to this problem. Now, Chinese scientists have come up with
‘waterjet printing’ that uses paper coated with dyes that change colour when wet and return to their colourless state when dry.
To create rewritable paper the researchers screened various organic compounds and picked four oxazolidines. The lower-energy closed ring isomers of these oxazolidines are colourless in the absence of water. But when the paper is wetted hydrogen bonding stabilises the more polar open ring form of the molecules, changing the dyes’ absorption of visible light. The exact wavelengths absorbed vary with the organic compound used, allowing the researchers to print in a variety of colours.
The rewriteable paper was made by first coating ordinary paper with a layer of polyethylene glycol (PEG) to prevent it reacting with the dye, before a second layer of PEG containing the chosen dye was laid on top. Finally, another layer of PEG was added to prevent the dye absorbing water from the air or, conversely, losing water too quickly.
The team used a commercial inkjet printer and a cartridge filled with water to print out their own Nature Communicationspaper on the dyes. The printed page is dry to the touch and the print can be rapidly ‘erased’ by heating it to 70°C. Under ambient conditions the print remained legible for around 22 hours before evaporation wiped the page clean. Paper prepared in this way can be printed on and then erased more than 50 times.
The researchers are now working to extend the print’s lifetime, but principal investigator Xiao-An Zhang of Jilin University says swift fading would have advantages for daily newspapers, for example. ‘After people had finished, they could put the paper back and the colour would disappear,’ he says. ‘Every morning you'd have a fresh issue.’ He suggests different papers could be manufactured on which printouts would last for different lengths of time. The team is also currently working towards multi-colour printouts. Zhang declines to give details but says ‘we have confidence that eventually we will deliver them’.
Organic photochemist Francisco Raymo of the University of Miami, US, who helped develop the dye molecules but was not involved in the latest research, says he was ‘very pleased to see that our molecules are being put to good use’. However, he suspects the idea's commercial prospects may be hampered by the need to specially prepare the paper with a multi-layer coating.
Link:
'Waterjet' printer set to make a splash | Chemistry World
shuttler
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Successful surgical operation of 3-D lower jaw bone implant in Naval 411 Hospital in Shanghai, the first in China
发布时间：2014-01-03 21:38 来源:中国海军
411医院成功完成国内首例3D打印下颌骨植入手术-今日要闻-中国海军网
Credit: mongcz.com
Credit: mongcz.com
发布时间：2014-01-03 21:38 来源:中国海军
411医院成功完成国内首例3D打印下颌骨植入手术-今日要闻-中国海军网
Credit: mongcz.com
Credit: mongcz.com
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shuttler
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China Builds Mammoth Detector to Probe Mysteries of Neutrino Mass
2014-02-10
Heavy hitter. China hopes its planned JUNO detector, 38 meters across, will be the first to nail which of the three neutrino flavors is heavier or lighter. CREDITS: (INSET) IHEP; (SOURCE) M. BLENNOW ET AL. ARXIV 1311.1822
It isn't easy to weigh a ghost. After neutrinos were hypothesized in 1930, it took physicists 67 years to prove that these elusive particles—which zip through our bodies by the trillions each second—have mass at all. Now, a Chinese-led team is planning a mammoth neutrino detector, meant to capture enough neutrinos from nearby nuclear reactors to determine which of the three known types, or flavors, of neutrinos are heavier or lighter. That mass hierarchy could be key to explaining how neutrinos get their mass, and measuring it would be a coup for China's particle physicists.
Last month, scientists gathered in Jiangmen, in China's southern Guangdong province, to review plans for the Jiangmen Underground Neutrino Observatory (JUNO). Groundbreaking is slated for later this year on the $300 million facility, which China aims to complete by 2019. The facility, which backers say will be twice as sensitive as existing detectors, should not only pin down key properties of neutrinos themselves but also detect telltale neutrinos from nuclear reactions in the sun, Earth, and supernovas.
Other planned facilities aim to reveal the mass hierarchy (see table), but China could be the first to arrive at an ironclad result. If China can pull it off, says William McDonough, a geologist at the University of Maryland, College Park, JUNO "will not only lead to breakthroughs in neutrino physics, but revolutionize the field of geology and astrophysics." A successful project would also mark another triumph for China's neutrino research, 2 years after the Daya Bay Reactor Neutrino Experiment in Guangdong nailed a key parameter describing how different types of neutrinos morph into one another (Science, 16 March 2012, p. 1287).
In 1998, physicists working with the subterranean particle detector Super-Kamiokande in Japan showed that neutrinos of one flavor, muon neutrinos generated by cosmic rays in the atmosphere, can change flavor as they zip through Earth. In 2001, researchers at the Sudbury Neutrino Observatory in Canada proved that electron neutrinos from the sun do the same. Such neutrino "oscillations" prove that neutrinos have mass: Without it, the particles would move at light speed and—according to relativity—time would stand still for them, making change impossible.
Knowing a neutrino has mass isn't the same as knowing what it weighs. In the simplest model, neutrino oscillations depend on just six parameters—the three mass differences among the neutrinos and three abstract "mixing angles." Physicists have measured all six—including the last mixing angle, which was measured by Daya Bay. They know that two of the neutrinos are close in mass and one is further off. But they don't know whether there are two lighter neutrinos and one heavier one—the so-called normal hierarchy—or an inverse hierarchy of two heavier ones and one light one.
How the masses shake out "is fundamental for a whole series of questions," says Wang Yifang, director of the Institute of High Energy Physics (IHEP) here, including whether neutrinos, like other particles, get mass from tangling with Higgs bosons or from a more exotic mechanism. The answer depends on whether the neutrino is, oddly, its own antiparticle. Physicists may be able to tell that by searching for a weird new type of radioactive decay. But, if it even exists, that decay would occur at an observable rate only if neutrinos follow an inverse hierarchy.
To explore this frontier, an international team led by Wang will build a detector 700 meters beneath a granite hill near Jiangmen, equidistant from two nuclear power plant complexes. A sphere about 38 meters in diameter will contain 20,000 tons of a material known as a liquid scintillator. About 60 times a day, one of the sextillion or so electron neutrinos spraying from the reactors every second should bump into an atomic nucleus, sparking a flash of scintillation light that the detector can measure and analyze. In the 53 kilometers that the neutrinos will traverse from reactor to detector, about 70% will change flavor, says Cao Jun, a particle physicist at IHEP. By studying the energy spectrum of the neutrinos, physicists should be able to tease out the mass hierarchy. "But it's not going to be easy because the amount of energy to be measured is minuscule," Cao says. He estimates the measurement will require 6 years of data-taking.
The key to JUNO's success will be its energy resolution. The largest liquid scintillation detector to date—KamLAND in Japan, which has 1000 tons of detector fluid—can only make out energy differences of greater than 6%. JUNO needs to double the resolution to 3%—no mean feat, especially as the larger volume of scintillator itself absorbs more light.
If it works, JUNO should also make finer measurements of the known mixing angles and mass differences. "This is particularly important for the search for a possible fourth form of neutrinos," says Lothar Oberauer of the Technical University of Munich in Germany. If the sum of all oscillations doesn't add up to 100%, then the data would point to a fourth flavor (Science, 21 October 2011, p. 304)—a possibility that could topple the standard model of particle physics and help explain a host of astronomical puzzles.
Another mission for JUNO is to observe geoneutrinos emitted during radioactive decay in Earth's deep interior, which generates heat that helps drive plate tectonics and power our planet's magnetic field. Detecting geoneutrinos "is the only way to get a glimpse of Earth's internal heat budget and distribution," McDonough says. The three facilities now detecting geoneutrinos, including the revamped Sudbury detector, record about 45 a year in total. JUNO should spot about 500 a year, enough to test various models of Earth's composition and heat flow, McDonough says. And that would score China another triumph in neutrino physics. (Science Magazine)
Above source: China Builds Mammoth Detector to Probe Mysteries of Neutrino Mass---Chinese Academy Of Sciences
Science magazine: China Builds Mammoth Detector to Probe Mysteries of Neutrino Mass
Strange Effects: The Mystifying History of Neutrino Experiments
Image: A physicist sits inside the LSND detector. (Los Alamos National Laboratory)
2014-02-10
Heavy hitter. China hopes its planned JUNO detector, 38 meters across, will be the first to nail which of the three neutrino flavors is heavier or lighter. CREDITS: (INSET) IHEP; (SOURCE) M. BLENNOW ET AL. ARXIV 1311.1822
It isn't easy to weigh a ghost. After neutrinos were hypothesized in 1930, it took physicists 67 years to prove that these elusive particles—which zip through our bodies by the trillions each second—have mass at all. Now, a Chinese-led team is planning a mammoth neutrino detector, meant to capture enough neutrinos from nearby nuclear reactors to determine which of the three known types, or flavors, of neutrinos are heavier or lighter. That mass hierarchy could be key to explaining how neutrinos get their mass, and measuring it would be a coup for China's particle physicists.
Last month, scientists gathered in Jiangmen, in China's southern Guangdong province, to review plans for the Jiangmen Underground Neutrino Observatory (JUNO). Groundbreaking is slated for later this year on the $300 million facility, which China aims to complete by 2019. The facility, which backers say will be twice as sensitive as existing detectors, should not only pin down key properties of neutrinos themselves but also detect telltale neutrinos from nuclear reactions in the sun, Earth, and supernovas.
Other planned facilities aim to reveal the mass hierarchy (see table), but China could be the first to arrive at an ironclad result. If China can pull it off, says William McDonough, a geologist at the University of Maryland, College Park, JUNO "will not only lead to breakthroughs in neutrino physics, but revolutionize the field of geology and astrophysics." A successful project would also mark another triumph for China's neutrino research, 2 years after the Daya Bay Reactor Neutrino Experiment in Guangdong nailed a key parameter describing how different types of neutrinos morph into one another (Science, 16 March 2012, p. 1287).
In 1998, physicists working with the subterranean particle detector Super-Kamiokande in Japan showed that neutrinos of one flavor, muon neutrinos generated by cosmic rays in the atmosphere, can change flavor as they zip through Earth. In 2001, researchers at the Sudbury Neutrino Observatory in Canada proved that electron neutrinos from the sun do the same. Such neutrino "oscillations" prove that neutrinos have mass: Without it, the particles would move at light speed and—according to relativity—time would stand still for them, making change impossible.
Knowing a neutrino has mass isn't the same as knowing what it weighs. In the simplest model, neutrino oscillations depend on just six parameters—the three mass differences among the neutrinos and three abstract "mixing angles." Physicists have measured all six—including the last mixing angle, which was measured by Daya Bay. They know that two of the neutrinos are close in mass and one is further off. But they don't know whether there are two lighter neutrinos and one heavier one—the so-called normal hierarchy—or an inverse hierarchy of two heavier ones and one light one.
How the masses shake out "is fundamental for a whole series of questions," says Wang Yifang, director of the Institute of High Energy Physics (IHEP) here, including whether neutrinos, like other particles, get mass from tangling with Higgs bosons or from a more exotic mechanism. The answer depends on whether the neutrino is, oddly, its own antiparticle. Physicists may be able to tell that by searching for a weird new type of radioactive decay. But, if it even exists, that decay would occur at an observable rate only if neutrinos follow an inverse hierarchy.
To explore this frontier, an international team led by Wang will build a detector 700 meters beneath a granite hill near Jiangmen, equidistant from two nuclear power plant complexes. A sphere about 38 meters in diameter will contain 20,000 tons of a material known as a liquid scintillator. About 60 times a day, one of the sextillion or so electron neutrinos spraying from the reactors every second should bump into an atomic nucleus, sparking a flash of scintillation light that the detector can measure and analyze. In the 53 kilometers that the neutrinos will traverse from reactor to detector, about 70% will change flavor, says Cao Jun, a particle physicist at IHEP. By studying the energy spectrum of the neutrinos, physicists should be able to tease out the mass hierarchy. "But it's not going to be easy because the amount of energy to be measured is minuscule," Cao says. He estimates the measurement will require 6 years of data-taking.
The key to JUNO's success will be its energy resolution. The largest liquid scintillation detector to date—KamLAND in Japan, which has 1000 tons of detector fluid—can only make out energy differences of greater than 6%. JUNO needs to double the resolution to 3%—no mean feat, especially as the larger volume of scintillator itself absorbs more light.
If it works, JUNO should also make finer measurements of the known mixing angles and mass differences. "This is particularly important for the search for a possible fourth form of neutrinos," says Lothar Oberauer of the Technical University of Munich in Germany. If the sum of all oscillations doesn't add up to 100%, then the data would point to a fourth flavor (Science, 21 October 2011, p. 304)—a possibility that could topple the standard model of particle physics and help explain a host of astronomical puzzles.
Another mission for JUNO is to observe geoneutrinos emitted during radioactive decay in Earth's deep interior, which generates heat that helps drive plate tectonics and power our planet's magnetic field. Detecting geoneutrinos "is the only way to get a glimpse of Earth's internal heat budget and distribution," McDonough says. The three facilities now detecting geoneutrinos, including the revamped Sudbury detector, record about 45 a year in total. JUNO should spot about 500 a year, enough to test various models of Earth's composition and heat flow, McDonough says. And that would score China another triumph in neutrino physics. (Science Magazine)
Above source: China Builds Mammoth Detector to Probe Mysteries of Neutrino Mass---Chinese Academy Of Sciences
Science magazine: China Builds Mammoth Detector to Probe Mysteries of Neutrino Mass
Strange Effects: The Mystifying History of Neutrino Experiments
Image: A physicist sits inside the LSND detector. (Los Alamos National Laboratory)
- Late last year, scientists with the OPERA collaboration in Gran Sasso, Italy reported an incredible finding: neutrinos that appeared to be moving faster than the speed of light.
The news spread at a barely slower pace, fascinating the public. One thing everyone knows is that a very famous physicist named Albert Einstein once said that nothing should travel faster than light speed.
In February, the OPERA researchers found a couple small problems with their experimental set-up, calling into question the original faster-than-light neutrino result. The event highlighted the difficulty of science at the edge of the unknown -- and neutrinos are especially tricky.
More often than not, neutrino experiments throughout history have turned up perplexing results. While most of these experiments didn’t get the high-profile attention that disputing Einstein provides, they've challenged scientists and helped them learn ever more about the natural world.
In this gallery, we take a look at some of the strangest historical neutrino results and the findings that still have scientists scratching their heads.
Above:
What Is a Neutrino?
Neutrinos are tiny, elusive and very common. For every proton or electron in the universe there are at least a billion neutrinos.
Researchers need to know how neutrinos work because they're relevant to many areas of physics. These ubiquitous specks came into existence milliseconds after the Big Bang, and new neutrinos are created during the radioactive decay of elements, nuclear reactions within stars and the explosive collapse of supernovas.
“They’re one of the dominant particles in the universe but we still know very little about them,” said physicist Bill Louis of Los Alamos National Lab, co-spokesperson for the MiniBooNE neutrino experiment.
Neutrinos are so hard to study because they barely interact with other matter. Unlike the more familiar electron, they have no electromagnetic charge. They pass as easily through lead walls as through mist, and are so light that scientists long thought they had no mass at all. Detecting them requires closely watching a large tank of material, such a water, on the off chance that a neutrino will hit another particle and produce an observable change.
More here:
Strange Effects: The Mystifying History of Neutrino Experiments - Wired Science
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cirr
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China's high-speed trains will soon receive wi-fi
After a two year wait, a wi-fi network is finally set to be installed on the mainland's high-speed trains
By Jeremy Blum
Passengers on the mainland's high-speed train network will soon be able to enjoy wi-fi access on their journeys, thanks to a network built by Chinese technology company Feitian.
"Providing high-speed mobile wi-fi access on trains necessitates specific technical requirements that are very different from accessing wi-fi in a home or office environment," Feitian research and development head Duan Shiping said in a Sina Technology interview.
"[Feitian's] high-speed train wi-fi system will provide passengers with a wealth of information and entertainment applications, but it will also give the train management staff a platform for communication and supervision."
In order to implement wi-fi, Duan said that Feitian had to meet signaling requirements and ensure that access to the mainland's largest wireless communication network providers - China Mobile, China Telecom and Cina Unicom - was viable along the high-speed rail's routes.
"Feitian [has been collaborating with] Southwest Jiaotong University and the railway departments [to] test the wi-fi system for one year now," Duan said, adding that the system would be finalised and implemented at a later date after receiving official government approval.
Currently, passengers on all mainland trains are only able to access the internet via 3G and 4G networks on mobile phones, although connection may be spotty depending on the train's location and speed.
Local reports have not indicated whether the upcoming wi-fi system will also be installed in China's non-high-speed trains.
Sina Technology netizens had a mixed reaction to the news, and many pointed out that talk of a high-speed railway wi-fi network had begun as early as 2011.
"[At this point], I'd rather just have a place to charge my phone on board the train," one commentator wrote. "A socket in each seat."
Others said that there was no indication the wi-fi network would be free of charge, and many expressed disappointment that it would likely be implemented after the beginning of Lunar New Year on January 30 - a time when massive-scale travel traditionally occurs in China as city workers return to the countryside to spend time with family.
In the greater China region, services for in-train wi-fi currently exist for Taiwan's High Speed Rail as well as Hong Kong's Airport Express
China's high-speed trains will soon receive wi-fi | South China Morning Post
After a two year wait, a wi-fi network is finally set to be installed on the mainland's high-speed trains
By Jeremy Blum
Passengers on the mainland's high-speed train network will soon be able to enjoy wi-fi access on their journeys, thanks to a network built by Chinese technology company Feitian.
"Providing high-speed mobile wi-fi access on trains necessitates specific technical requirements that are very different from accessing wi-fi in a home or office environment," Feitian research and development head Duan Shiping said in a Sina Technology interview.
"[Feitian's] high-speed train wi-fi system will provide passengers with a wealth of information and entertainment applications, but it will also give the train management staff a platform for communication and supervision."
In order to implement wi-fi, Duan said that Feitian had to meet signaling requirements and ensure that access to the mainland's largest wireless communication network providers - China Mobile, China Telecom and Cina Unicom - was viable along the high-speed rail's routes.
"Feitian [has been collaborating with] Southwest Jiaotong University and the railway departments [to] test the wi-fi system for one year now," Duan said, adding that the system would be finalised and implemented at a later date after receiving official government approval.
Currently, passengers on all mainland trains are only able to access the internet via 3G and 4G networks on mobile phones, although connection may be spotty depending on the train's location and speed.
Local reports have not indicated whether the upcoming wi-fi system will also be installed in China's non-high-speed trains.
Sina Technology netizens had a mixed reaction to the news, and many pointed out that talk of a high-speed railway wi-fi network had begun as early as 2011.
"[At this point], I'd rather just have a place to charge my phone on board the train," one commentator wrote. "A socket in each seat."
Others said that there was no indication the wi-fi network would be free of charge, and many expressed disappointment that it would likely be implemented after the beginning of Lunar New Year on January 30 - a time when massive-scale travel traditionally occurs in China as city workers return to the countryside to spend time with family.
In the greater China region, services for in-train wi-fi currently exist for Taiwan's High Speed Rail as well as Hong Kong's Airport Express
China's high-speed trains will soon receive wi-fi | South China Morning Post
shuttler
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Chinese Scientists Develop Fire Resistant Paper
2014-02-15 06:20:11 People's Daily Online Web Editor: Fei
A comparative test shows the fire resistant paper is well-preserved after being put over an alcohol lamp flame for 30 seconds, while ordinary paper is burnt to ashes in six seconds. [Photo: Taiyuan Evening Newspaper]
Fire has been a nightmare for paper historical relics. Researchers with Shanghai institute of Ceramics, Chinese Academy of Sciences, have developed a new paper which is resistant to fire. Even under (at) 1,000 degrees Celsius, the paper will not burn. They made this new substance from calcium phosphate compound. The research was published in "Chemistry - A European Journal" on Jan. 27, 2014.
This novel kind of inorganic paper is flexible and incombustible, but still feels like ordinary paper. It can be torn, folded, and destroyed by strong acid. It can be used for important documents - preserving them for prolonged periods of time.
Chinese Scientists Develop Fire Resistant Paper
2014-02-15 06:20:11 People's Daily Online Web Editor: Fei
A comparative test shows the fire resistant paper is well-preserved after being put over an alcohol lamp flame for 30 seconds, while ordinary paper is burnt to ashes in six seconds. [Photo: Taiyuan Evening Newspaper]
Fire has been a nightmare for paper historical relics. Researchers with Shanghai institute of Ceramics, Chinese Academy of Sciences, have developed a new paper which is resistant to fire. Even under (at) 1,000 degrees Celsius, the paper will not burn. They made this new substance from calcium phosphate compound. The research was published in "Chemistry - A European Journal" on Jan. 27, 2014.
This novel kind of inorganic paper is flexible and incombustible, but still feels like ordinary paper. It can be torn, folded, and destroyed by strong acid. It can be used for important documents - preserving them for prolonged periods of time.
Chinese Scientists Develop Fire Resistant Paper
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shuttler
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China robot studies SW Indian Ocean seabed
English.news.cn 2014-02-13 20:17:32
Credit：news.xinhuanet.com
Credit: :news.xinhuanet.com
" 大洋 1号 Dayang-1" oceanic research vessel
BEIJING, Feb. 13 (Xinhua) -- China has used a domestically made underwater robot to study polymetallic sulfide in the southwest Indian Ocean, the State Oceanic Administration (SOA) said on Thursday.
Scientists aboard the "Dayang-1" oceanic research vessel remotely operated the "Hailong" unmanned underwater vehicle on five occasions from late January to early February, with one of their five attempts failing.
They found sulfide in more areas of China's exploration contract area, and gained new understanding of the characteristics of the carbonate area, according to the SOA.
This detailed information is important for China's future research in the polymetallic sulfide exploration contract area, the SOA said.
The hydrothermal sulfide is a kind of sea-bed deposit containing copper, zinc and precious metals such as gold and silver. Those metals formed sulfides after chemical reactions and came to rest in the seabed in "chimney vents."
With the help of the Hailong, scientists observed these vents, blind shrimp and fish as well as other creatures in hydrothermal areas. The underwater vehicle also extracted a tube of water samples.
Chief expedition scientist Tao Chunhui said the high-precision positioning, real-time control, observation, picture-taking and sampling in this task could not have been achieved with conventional survey methods.
shuttler
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China tops Europe in R&D intensity
Reforms to commercial and academic research systems still needed despite reaching spending milestone, say scientists.
Richard Van Noorden
08 January 2014
ChinaFotoPress via Getty Images
Research at computer firm Lenovo is helping to drive China’s rising R&D spending.
By pouring cash into science and technology faster than its economy has expanded, China has for the first time overtaken Europe on a key measure of innovation: the share of its economy devoted to research and development (R&D).
In 2012, China invested 1.98% of its gross domestic product (GDP) into R&D — just edging out the 28 member states of the European Union (EU), which together managed 1.96%, according to the latest estimates of research intensity, to be released this month by the Paris-based Organisation for Economic Co-operation and Development (OECD).
The figures show that China’s research intensity has tripled since 1998, whereas Europe’s has barely increased (see ‘Shooting star’). The numbers are dominated by business spending, reflecting China’s push in the manufacturing and information- and communication-technology industries.
James Wilsdon, a science-policy analyst at the University of Sussex in Brighton, UK, says that China’s R&D juggernaut is “astonishing”, considering that the entire system emerged only after the end of the Cultural Revolution in 1976. In absolute terms, China’s R&D spending is still almost one-third lower than that of Europe, but the new figures are “a significant milestone”, says Wilsdon.
The reorientation of China’s economy displays its soaring ambition. However, money does not buy innovation. Despite success in some areas, notably high-speed rail, solar energy, supercomputing and space exploration, leaders in China are concerned that innovation is lacking, say science-policy analysts. “Chinese leaders would like something equivalent to a Nobel prize, or a world-class product similar to an iPhone,” says Denis Simon, an expert on Chinese science and innovation at Arizona State University in Tempe. “But there is a lot of risk aversion within the Chinese R&D system that doesn’t allow for entrepreneurial behaviour.”
Source: OECD
Horizon 2020 deal reached in Brussels
More related stories
Some analysts argue that Europe does not need to be too worried by the stasis in research intensity. The number is an increasingly poor indicator of innovative activity, argues Kieron Flanagan, a science-policy analyst at the University of Manchester, UK. For example, it fails to pick up on innovation in the service-oriented industries that dominate many Western economies. An architectural or advertising firm could innovate while meeting the demands of a contract — making advances that could be widely copied and meaningfully affect an economy. Yet they would not count as R&D spending.
In China, meanwhile, “a great stodgy mass” of state-owned enterprises dominates commercial R&D spending — and they might actually suppress innovation, says Wilsdon. According to a study co-authored by Wilsdon and published in October 2013 by the innovation charity Nesta, based in London, the state companies might block more-inventive small and medium-sized enterprises. China, the study argues, is an “absorptive state”: one that adopts and adapts incoming technologies from overseas but does little breakthrough research. However, Wilsdon points to a few eye-catching bright spots: privately held, globally minded companies that include the telecommunications firms Huawei Technologies and ZTE, the e-commerce giant Alibaba and the computer firm Lenovo.
China’s emphasis on applied and product-development research means that funding for basic science remains low: only 5% of the country’s total R&D is devoted to this, compared with 15–20% in other major OECD nations. That money has to support a larger number of researchers who are already poorly paid, says Xue. Many academics, he says, complement their salaries by taking on short-term projects for industry — work that can distract their focus from fundamental science problems.
Funding and evaluation systems suffer other distortions, says Cong Cao, a science-policy analyst at the University of Nottingham, UK. Grant money is not disbursed transparently, and basic-research funding tends to go to eminent scientists and safe projects, he says, with academics judged mechanically on the number of publications that they author. A staggering rise in scientific output has not yet been matched by an equivalent rise in highly cited articles; swathes of patents are filed but rarely used. Wilsdon says that world-class research occurs at the country’s top 30 universities and at Chinese Academy of Science institutes. “But it is still very patchy, and a lot of it is reliant on a relatively small number of outstanding scientists lured back from overseas,” he says.
Simon adds that China’s scientists need more independence and freedom to work on risky projects. Such changes might be on the way: Cao expects that at the forthcoming review of China’s 2006 science plan, funding agencies will be told to be more transparent about their grants and grantees, and Chinese researchers will be allowed to use more of their funding to boost the salaries of research staff.
One of the plan’s paramount goals seems to be right on target, however: China, unlike Europe, looks set to boost its research spending to 2.5% of GDP by 2020.
Nature 505,144–145 (09 January 2014) doi:10.1038/505144a
China tops Europe in RD intensity : Nature News & Comment
Reforms to commercial and academic research systems still needed despite reaching spending milestone, say scientists.
Richard Van Noorden
08 January 2014
ChinaFotoPress via Getty Images
Research at computer firm Lenovo is helping to drive China’s rising R&D spending.
By pouring cash into science and technology faster than its economy has expanded, China has for the first time overtaken Europe on a key measure of innovation: the share of its economy devoted to research and development (R&D).
In 2012, China invested 1.98% of its gross domestic product (GDP) into R&D — just edging out the 28 member states of the European Union (EU), which together managed 1.96%, according to the latest estimates of research intensity, to be released this month by the Paris-based Organisation for Economic Co-operation and Development (OECD).
The figures show that China’s research intensity has tripled since 1998, whereas Europe’s has barely increased (see ‘Shooting star’). The numbers are dominated by business spending, reflecting China’s push in the manufacturing and information- and communication-technology industries.
James Wilsdon, a science-policy analyst at the University of Sussex in Brighton, UK, says that China’s R&D juggernaut is “astonishing”, considering that the entire system emerged only after the end of the Cultural Revolution in 1976. In absolute terms, China’s R&D spending is still almost one-third lower than that of Europe, but the new figures are “a significant milestone”, says Wilsdon.
The reorientation of China’s economy displays its soaring ambition. However, money does not buy innovation. Despite success in some areas, notably high-speed rail, solar energy, supercomputing and space exploration, leaders in China are concerned that innovation is lacking, say science-policy analysts. “Chinese leaders would like something equivalent to a Nobel prize, or a world-class product similar to an iPhone,” says Denis Simon, an expert on Chinese science and innovation at Arizona State University in Tempe. “But there is a lot of risk aversion within the Chinese R&D system that doesn’t allow for entrepreneurial behaviour.”
Source: OECD
Horizon 2020 deal reached in Brussels
More related stories
Some analysts argue that Europe does not need to be too worried by the stasis in research intensity. The number is an increasingly poor indicator of innovative activity, argues Kieron Flanagan, a science-policy analyst at the University of Manchester, UK. For example, it fails to pick up on innovation in the service-oriented industries that dominate many Western economies. An architectural or advertising firm could innovate while meeting the demands of a contract — making advances that could be widely copied and meaningfully affect an economy. Yet they would not count as R&D spending.
In China, meanwhile, “a great stodgy mass” of state-owned enterprises dominates commercial R&D spending — and they might actually suppress innovation, says Wilsdon. According to a study co-authored by Wilsdon and published in October 2013 by the innovation charity Nesta, based in London, the state companies might block more-inventive small and medium-sized enterprises. China, the study argues, is an “absorptive state”: one that adopts and adapts incoming technologies from overseas but does little breakthrough research. However, Wilsdon points to a few eye-catching bright spots: privately held, globally minded companies that include the telecommunications firms Huawei Technologies and ZTE, the e-commerce giant Alibaba and the computer firm Lenovo.
China’s emphasis on applied and product-development research means that funding for basic science remains low: only 5% of the country’s total R&D is devoted to this, compared with 15–20% in other major OECD nations. That money has to support a larger number of researchers who are already poorly paid, says Xue. Many academics, he says, complement their salaries by taking on short-term projects for industry — work that can distract their focus from fundamental science problems.
Funding and evaluation systems suffer other distortions, says Cong Cao, a science-policy analyst at the University of Nottingham, UK. Grant money is not disbursed transparently, and basic-research funding tends to go to eminent scientists and safe projects, he says, with academics judged mechanically on the number of publications that they author. A staggering rise in scientific output has not yet been matched by an equivalent rise in highly cited articles; swathes of patents are filed but rarely used. Wilsdon says that world-class research occurs at the country’s top 30 universities and at Chinese Academy of Science institutes. “But it is still very patchy, and a lot of it is reliant on a relatively small number of outstanding scientists lured back from overseas,” he says.
Simon adds that China’s scientists need more independence and freedom to work on risky projects. Such changes might be on the way: Cao expects that at the forthcoming review of China’s 2006 science plan, funding agencies will be told to be more transparent about their grants and grantees, and Chinese researchers will be allowed to use more of their funding to boost the salaries of research staff.
One of the plan’s paramount goals seems to be right on target, however: China, unlike Europe, looks set to boost its research spending to 2.5% of GDP by 2020.
Nature 505,144–145 (09 January 2014) doi:10.1038/505144a
China tops Europe in RD intensity : Nature News & Comment
shuttler
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Successful surgical operation of 3-D lower jaw bone implant in Naval 411 Hospital in Shanghai, the first in China
发布时间：2014-01-03 21:38 来源:中国海军
411医院成功完成国内首例3D打印下颌骨植入手术-今日要闻-中国海军网
Credit: mongcz.com
Credit: mongcz.com
Meantime in Guangdong province:
Surgery performed using 3D printing technology
By ZHENG CAIXIONG (chinadaily.com.cn) Updated: 2014-02-13 17:34
Comments Print Mail Large Medium Small
Credit: info.ebnew
Credit:.familydoctor.com.cn
Credit: mendmyhip.com
A hospital in Guangdong province successfully performed surgery on a patient who suffered from acetabular fractures using 3D printing technology, Southern Metropolis Daily reported on Thursday.
The full simulation of the "fracture of acetabulum" was printed out by a 3D printer before the surgery was conducted at the No 3 Hospital Affiliated to Southern Medical University in the provincial capital Guangzhou.
The patient surnamed Zhang, 43, who suffered serious acetabular fractures in a fall, could sit up the second day after the surgery.
It was the first time 3D printing technology has been in clinical treatment in the southern province.
Surgery performed using 3D printing technology - China - Chinadaily.com.cn
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cirr
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A world's first，a triboelectrification-based thin-film nanogenerator，using （acoustic vibrations）noise pollution to generate electricity。
Triboelectrification-Based Organic Film Nanogenerator for Acoustic Energy Harvesting and Self-Powered Active Acoustic Sensing
Jin Yang†‡, Jun Chen†, Ying Liu†, Weiqing Yang†,Yuanjie Su†, and Zhong Lin Wang*†§
† School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta. Georgia 30332-0245,United States
‡ Department of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China
§ Beijing Institute of Nanoenergy and Nanosystems,Chinese Academy of Sciences, Beijing 100083, China
ACS Nano, Article ASAP
DOI: 10.1021/nn4063616
Publication Date (Web): February 13, 2014
Copyright © 2014 American Chemical Society
*Address correspondence to zhong.wang@mse.gatech.edu.
Abstract
As a vastly available energy source in our daily life, acoustic vibrations are usually taken as noise pollution with little use as a power source. In this work, we have developed a triboelectrification-based thin-film nanogenerator for harvesting acoustic energy from ambient environment. Structured using a polytetrafluoroethylene thin film and a holey aluminum film electrode under carefully designed straining conditions, the nanogenerator is capable of converting acoustic energy into electric energy via triboelectric transduction. With an acoustic sensitivity of 9.54 V Pa–1 in a pressure range from 70 to 110 dB and a directivity angle of 52°, the nanogenerator produced a maximum electric power density of 60.2 mW m–2, which directly lit 17 commercial light-emitting diodes (LEDs). Furthermore, the nanogenerator can also act as a self-powered active sensor for automatically detecting the location of an acoustic source with an error less than 7 cm. In addition, an array of devices with varying resonance frequencies was employed to widen the overall bandwidth from 10 to 1700 Hz, so that the nanogenerator was used as a superior self-powered microphone for sound recording. Our approach presents an adaptable, mobile, and cost-effective technology for harvesting acoustic energy from ambient environment, with applications in infrastructure monitoring, sensor networks, military surveillance, and environmental noise reduction.
Triboelectrification-Based Organic Film Nanogenerator for Acoustic Energy Harvesting and Self-Powered Active Acoustic Sensing - ACS Nano (ACS Publications)
Triboelectrification-Based Organic Film Nanogenerator for Acoustic Energy Harvesting and Self-Powered Active Acoustic Sensing
Jin Yang†‡, Jun Chen†, Ying Liu†, Weiqing Yang†,Yuanjie Su†, and Zhong Lin Wang*†§
† School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta. Georgia 30332-0245,United States
‡ Department of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China
§ Beijing Institute of Nanoenergy and Nanosystems,Chinese Academy of Sciences, Beijing 100083, China
ACS Nano, Article ASAP
DOI: 10.1021/nn4063616
Publication Date (Web): February 13, 2014
Copyright © 2014 American Chemical Society
*Address correspondence to zhong.wang@mse.gatech.edu.
Abstract
As a vastly available energy source in our daily life, acoustic vibrations are usually taken as noise pollution with little use as a power source. In this work, we have developed a triboelectrification-based thin-film nanogenerator for harvesting acoustic energy from ambient environment. Structured using a polytetrafluoroethylene thin film and a holey aluminum film electrode under carefully designed straining conditions, the nanogenerator is capable of converting acoustic energy into electric energy via triboelectric transduction. With an acoustic sensitivity of 9.54 V Pa–1 in a pressure range from 70 to 110 dB and a directivity angle of 52°, the nanogenerator produced a maximum electric power density of 60.2 mW m–2, which directly lit 17 commercial light-emitting diodes (LEDs). Furthermore, the nanogenerator can also act as a self-powered active sensor for automatically detecting the location of an acoustic source with an error less than 7 cm. In addition, an array of devices with varying resonance frequencies was employed to widen the overall bandwidth from 10 to 1700 Hz, so that the nanogenerator was used as a superior self-powered microphone for sound recording. Our approach presents an adaptable, mobile, and cost-effective technology for harvesting acoustic energy from ambient environment, with applications in infrastructure monitoring, sensor networks, military surveillance, and environmental noise reduction.
Triboelectrification-Based Organic Film Nanogenerator for Acoustic Energy Harvesting and Self-Powered Active Acoustic Sensing - ACS Nano (ACS Publications)
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