China Science & Technology Forum

[JSCh]

American, Chinese scientists develop new catalyst to help harvest, store clean energy
Source: Xinhua| 2018-03-06 05:11:54|Editor: Mu Xuequan

WASHINGTON, March 5 (Xinhua) -- American and Chinese scientists have synthesized a new, dual-atom catalyst to serve as a platform for artificial photosynthesis, a move that may help harvest and store solar energy more efficiently.

In a study reported on Monday in the Proceedings of the National Academy of Science, scientists displayed an iridium catalyst with only two active metal centers, which can directly harvest solar energy and store the energy in chemical bonds, similar to how photosynthesis is performed but with higher efficiencies and lower cost.

Dunwei Wang, Boston College Associate Professor of Chemistry and the paper's lead author, said, "It addresses the critical challenge that solar energy is intermittent," using the "atomically dispersed catalyst" featuring two atoms.

Researchers synthesized an iridium dinuclear heterogeneous catalyst in a facile photochemical way. They reported that the catalyst showed outstanding stability and high activity toward water oxidation, an essential process in natural and artificial photosynthesis.

According to researchers, challenges are that most active heterogeneous catalysts are often poorly defined in their atomic structures, which makes it difficult to evaluate the detailed mechanisms at the molecular level.

Heterogeneous catalysts, widely used in large-scale industrial chemical transformations, involve the form of catalysis where the phase of the catalyst differs from that of the reactants.

Wang said they managed to determine the smallest active and most durable heterogeneous catalyst unit for water oxidation, previously known only to be done for homogeneous catalysts, whose durability was poor.

They also performed X-ray experiments to determine the structure of the iridium catalyst at Lawrence Berkeley National Laboratory.

Wang said the team was surprised by the simplicity and durability of the catalyst, combined with the high activity toward the desired reaction of water oxidation.

Scientists from the University of California, Irvin; Yale, Tufts, and China's Tsinghua and Nanjing Universities also participated the research.

Yanyan Zhao, Ke R. Yang, Zechao Wang, Xingxu Yan, Sufeng Cao, Yifan Ye, Qi Dong, Xizi Zhang, James E. Thorne, Lei Jin, Kelly L. Materna, Antonios Trimpalis, Hongye Bai, Sirine C. Fakra, Xiaoyan Zhong, Peng Wang, Xiaoqing Pan, Jinghua Guo, Maria Flytzani-Stephanopoulos, Gary W. Brudvig, Victor S. Batista, Dunwei Wang. Stable iridium dinuclear heterogeneous catalysts supported on metal-oxide substrate for solar water oxidation. Proceedings of the National Academy of Sciences, 2018; 201722137 DOI: 10.1073/pnas.1722137115​

 

[cirr]

Chinese scientists create gas detector as sensitive as dog's sniffer

2018-03-08 09:25 Xinhua Editor: Gu Liping

A team of Chinese scientists has used graphene to create an artificial gas detector that is as good as a dog's nose.

The study, reported Wednesday in ACS Nano, a monthly scientific journal of the American Chemical Society, showed that the graphene-based nanoscrolls can mimic a dog's sensitive sniffer, which is lined with millions of tiny capillaries.

It is well known that dogs have a better sense of smell than humans. For years, scientists have been trying to develop an artificial detector that is just as good as a canine's nose.

Drawing inspiration from the capillary structure, researchers from South China Normal University and Beihang University found a way to modify the graphene with a polymer to make high-quality nanoscrolls.

These nanoscrolls have a large surface area like that in dog's nose. They are stable at high temperatures, and are strong and durable.

Previous studies have produced the graphene-based nanoscrolls, which are nanosheets of graphene rolled up in continuous and uniform manner.

But they are difficult to manufacture, consume a lot of energy and difficult to scale up.

And past studies have used raw graphene or modified graphene that either left behind some unrolled structures, or shriveled up and aggregated, respectively.

The team prepared graphene-based nanoscrolls with the addition of poly or sodium-p-stryrenesulfonate, using the freeze-drying method to create uniform, unaggregated structures.

It showed that the nanoscrolls had a wide, tubular shape, and almost all of the graphene was rolled up.

The researchers then incorporated the nanoscrolls into a gas sensor, which was highly selective and sensitive.

They said that this method had the potential for large-scale production.

http://www.ecns.cn/2018/03-08/294980.shtml

 

[JSCh]

Fiber-fermenting bacteria improve health of type 2 diabetes patients
March 8, 2018, Rutgers University

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Gut bacteria in culture. Credit: Tao Liu and Xiaoyan Pang/Shanghai Jiao Tong University

The fight against type 2 diabetes may soon improve thanks to a pioneering high-fiber diet study led by a Rutgers University-New Brunswick professor.

Promotion of a select group of gut bacteria by a diet high in diverse fibers led to better blood glucose control, greater weight loss and better lipid levels in people with type 2 diabetes, according to research published today in Science.

The study, underway for six years, provides evidence that eating more of the right dietary fibers may rebalance the gut microbiota, or the ecosystem of bacteria in the gastrointestinal tract that help digest food and are important for overall human health.

"Our study lays the foundation and opens the possibility that fibers targeting this group of gut bacteria could eventually become a major part of your diet and your treatment," said Liping Zhao, the study's lead author and a professor in the Department of Biochemistry and Microbiology, School of Environmental and Biological Sciences at Rutgers University-New Brunswick.

Type 2 diabetes, one of the most common debilitating diseases, develops when the pancreas makes too little insulin - a hormone that helps glucose enter cells for use as energy - or the body doesn't use insulin well.

In the gut, many bacteria break down carbohydrates, such as dietary fibers, and produce short-chain fatty acids that nourish our gut lining cells, reduce inflammation and help control appetite. A shortage of short-chain fatty acids has been associated with type 2 diabetes and other diseases. Many clinical studies also show that increasing dietary fiber intake could alleviate type 2 diabetes, but the effectiveness can vary due to the lack of understanding of the mechanisms, according to Zhao, who works in New Jersey Institute for Food, Nutrition, and Health at Rutgers-New Brunswick.

In research based in China, Zhao and scientists from Shanghai Jiao Tong University and Yan Lam, a research assistant professor in Zhao's lab at Rutgers, randomized patients with type 2 diabetes into two groups. The control group received standard patient education and dietary recommendations. The treatment group was given a large amount of many types of dietary fibers while ingesting a similar diet for energy and major nutrients. Both groups took the drug acarbose to help control blood glucose.

The high-fiber diet included whole grains, traditional Chinese medicinal foods rich in dietary fibers and prebiotics, which promote growth of short-chain fatty acid-producing gut bacteria. After 12 weeks, patients on the high-fiber diet had greater reduction in a three-month average of blood glucose levels. Their fasting blood glucose levels also dropped faster and they lost more weight.

Surprisingly, of the 141 strains of short-chain fatty acid-producing gut bacteria identified by next-generation sequencing, only 15 are promoted by consuming more fibers and thus are likely to be the key drivers of better health. Bolstered by the high-fiber diet, they became the dominant strains in the gut after they boosted levels of the short-chain fatty acids butyrate and acetate. These acids created a mildly acidic gut environment that reduced populations of detrimental bacteria and led to increased insulin production and better blood glucose control.

The study supports establishing a healthy gut microbiota as a new nutritional approach for preventing and managing type 2 diabetes.



https://medicalxpress.com/news/2018-03-fiber-fermenting-bacteria-health-diabetes-patients.html

Liping Zhao, Feng Zhang, Xiaoying Ding, Guojun Wu, Yan Y. Lam, Xuejiao Wang, Huaqing Fu, Xinhe Xue, Chunhua Lu, Jilin Ma, Lihua Yu, Chengmei Xu, Zhongying Ren, Ying Xu, Songmei Xu, Hongli Shen, Xiuli Zhu, Yu Shi, Qingyun Shen, Weiping Dong, Rui Liu, Yunxia Ling, Yue Zeng, Xingpeng Wang, Qianpeng Zhang, Jing Wang, Linghua Wang, Yanqiu Wu, Benhua Zeng, Hong Wei, Menghui Zhang, Yongde Peng, Chenhong Zhang. Gut bacteria selectively promoted by dietary fibers alleviate type 2 diabetes. Science, 2018; 359 (6380): 1151 DOI: 10.1126/science.aao5774​

 

[JSCh]

Chinese, Japanese scientists identify new material for making quantum computers
Source: Xinhua| 2018-03-09 03:28:45|Editor: Mu Xuequan


WASHINGTON, March 8 (Xinhua) -- Chinese and Japanese researchers have found a new kind of topological superconductor that can become a promising candidate in making the future quantum computers.

In a paper published on Thursday in the journal Science, Zhang Peng, a post-doctoral researcher at University of Tokyo, and his colleagues attained three key types of measurement necessary to analyze the quantum phase of Fe (Te, Se) in detail.

They confirmed that the surface of the material is suitable to support an exotic quasiparticles called Majorana bound states (MBSs). The MBSs was first proposed by Italian theoretical physicist Ettore Majorana. Utilizing the properties of MBSs is now believed as a promising path towards topological quantum computing.

According to researchers, the Majorana bound state, existing on edges of two-dimensional topological superconductors, is a fermion that is its own antiparticle. An exchange of two MBSs can result in the change of the system state, thus offering possibilities for quantum computing.

Quantum computers are poised to revolutionize society by tackling problems that conventional computers cannot. But most quantum computers currently in development are susceptible to the problem of decoherence, where the quantum state that encodes information degrades, which causes intolerable computing errors.

Zhang Peng told Xinhua, "a solution would be to develop topological quantum computers, where the integrity of the quantum state is protected by the topological properties of the system."

"In topological state, the local noises cannot disturb the topological properties unless the noises are so loud to cripple the whole system," Zhang explained.

But identifying materials that would be suitable to host MBSs is extremely challenging, according to Zhang.

He said this is the first time that the topological superconducting is found on crystals of Fe (Te, Se).

Unlike other topological superconductors identified to date, Zhang's team created the topological superconducting in a single crystal, on which the stable MBSs can be achieved relatively easily.

"It can promote the development of quantum computing," he said.

 

[JSCh]

China Focus: Chinese scientists find key factor activating genome expression in human embryos
Source: Xinhua| 2018-03-09 01:07:55|Editor: Jiaxin

By Xinhua writer Quan Xiaoshu

BEIJING, March 9 (Xinhua) -- Chinese scientists have identified the crucial factor that activates gene expression in human embryos, bringing them a step closer to explaining the mystery of human development at a very early embryonic stage, according to a paper published on the website of the scientific journal, Cell.

Human life starts from a fertilized egg. However, in the first two days after fertilization, almost no genes are expressed in human embryos. Previously scientists did not know how genomes become active and start gene expression in early embryos.

"What activates gene expression? The puzzle has been troubling scientists around the world for a long time. We were the first to find it," said Liu Jiang, senior author of the paper.

During human growth, different genes must be expressed at the right time and right place. The genetic code stored in DNA is "interpreted" by gene expression, which gives rise to all the particular features of an individual.

A team from Beijing Institute of Genomics, Chinese Academy of Sciences (CAS), led by Liu, together with a group from Center for Reproductive Medicine, Shandong University, under Chen Zijiang, and a group from Guangzhou Medical University under Liu Jianqiao, found that Oct-4, a transcriptional factor, plays a crucial role in activating zygotic genome expression.

In the first two days, a human zygote will grow into eight cells after three cell divisions. Once the embryo has eight cells, it will generate a sufficient amount of Oct-4, which will directly bind with DNA and switch on the gene expression, Liu said.

The research also found genome activation follows a particular sequence. "The older genes usually start expression at early embryonic stages, and younger ones at later stages," Liu said.

Humans have more than 20,000 genes, a reflection of a long chain of evolution. Some genes originated at the beginning of life on Earth, and are thus very old genes. Some originated in mammals, and are young ones. Some originated only in humans, and are deemed the youngest.

"We found that the expression of older genes usually occur at earlier embryonic stages, as these genes, shared by more life species, are needed during earlier development," Liu said.

But how human genome differentiates between old and young genes is still unclear and needs further study.

The study also found that transposons, a class of DNA elements, are very active in early human embryos, which might be a trigger of evolution.

"These transposons can jump from one position to another in a genome, and introduce DNA mutations. Since they are only active in early embryos, but not in differentiated tissues, the mutations caused by their mobility are more likely to be passed to the germ line, and then to the next generations," Liu said.

"As DNA mutations drive evolution, we believe that these active transposons have a big impact on human evolution," he said.

Before this study, the major hurdle in this research was the limited number of human embryos for experiment. Similar research would normally consume millions of animal embryos, but acquiring so many human embryos was neither possible nor ethical.

"We optimized the experiment methods so that the research could perform the assay with a very small number of human embryos," Liu said.

According to the paper, the scientists used just 50 to 100 cells, all derived from in vitro fertilization with written consent from donor couples.

 

[JSCh]

Chinese, American scientists "light up" lung cancer mutations
Source: Xinhua| 2018-03-08 05:13:18|Editor: Mu Xuequan


WASHINGTON, March 7 (Xinhua) -- Chinese and American scientists have found a new way to identify non-small cell lung cancers (NSCLC), the most common type of lung cancer, non-invasively.

In a study reported on Wednesday in the journal Science Translational Medicine, the scientists used a radio-labeled chemical tracer to mark certain cancer mutations, which can help determine sensitivity to and the efficacy of a therapy called tyrosine kinase inhibition in NSCLC patients.

NSCLC with those mutations can be best treated with drugs called tyrosine kinase inhibitors.

The inhibitors can extend median survival time of cancer patients with a mutation in the epidermal growth factor receptor or EGFR protein to greater than two years, more than twice the survival of patients receiving only chemotherapy.

However, it is not easy for clinicians to swiftly tell which cancers have this mutation and are therefore likely to respond to tyrosine kinase inhibition, according to researchers.

Although several techniques are currently available to assess EGFR mutations, these methods require biopsied samples and can often fail because of insufficient sample quantities for analysis.

An international team from Harbin Medical University, Fudan University and Stanford University has developed a chemical tracer that can light up EGFR mutations in the tumor cells, so the positron emission tomography (PET) and computed tomography (CT) imaging scans can detect them.

"We develop a kind molecular probe called 18F-MPG that can bind specifically with EGFR mutations," Sun Xilin, the paper's lead author at the Fourth Hospital of Harbin Medical University, told Xinhua.

Researchers tested the tracer in animal models with NSCLC and in primary and metastatic tumors from people with the cancer. They found that EGFR mutation detection by labeled PET and CT scans and by traditional biopsy were in agreement nearly 85 percent of the time.

In the study, patients with the EGFR mutation, detected by the tracer, lived longer without a progression in their cancers and they responded to tyrosine kinase inhibitors at a higher rate than those without the mutation.

"When we know EGFR mutations, a total of 70 percent of cancer patients respond to the therapy, but only 20 percent respond if we don't know their mutations," Sun said.

 

[JSCh]

New chip technology can lead to better quantum computing power: study
Source: Xinhua| 2018-03-09 22:47:14|Editor: Chengcheng


LONDON, March 9 (Xinhua) -- An international team, including Chinese researchers, has demonstrated a large-scale integrated quantum photonic circuit, which may pave the way for manufacturing massive components for the realization of an optical quantum computer, according to a study recently released by the University of Bristol.

Integrated Quantum Photonics allows the routing and control of single particles of light with intrinsically high stability and precision, however to date it has been limited to small-scale demonstrations in which only a small number of components are integrated on a chip.

Scaling up these quantum circuits is of paramount importance to increasing the complexity and computational power of modern quantum information processing technologies.

In this study, published in the journal Science, researchers managed to integrate in a single chip 550 optical components, allowing the integrated photonic chip to entangle photons to incredible levels of precision. The chip was realized using a scalable silicon photonics technology, similar to today's electronic circuits.

"Our quantum chip allows us to reach unprecedented levels of precision and control of multidimensional entanglement, a key factor in many quantum information tasks of computing and communication," said lead author, Dr Jianwei Wang from the University of Bristol.

The chip sets a new standard for complexity and precision of quantum photonics, with immediate applications for quantum technologies, according to the study.

"The development of powerful large-scale integrated photonic quantum chips will provide an efficient route to the future applications in the fields of quantum communication, quantum computing and many others," said Prof. Qihuang Gong, the lead academic from Peking University.

 

[cirr]

Chinese scientists find gene that increases corn yields

2018-03-10 09:25 Xinhua Editor: Wang Fan

Chinese scientists have found a gene that can help grow bigger grains of corn to raise yields.

The gene, named urb2, is crucial in the growth of grains, according to the research by Henan Agricultural University and Chinese Academy of Agricultural Sciences.

The result of the research can help increase corn yields and lay a foundation for related studies in breeding, said Tang Jihua, head of the research team.

The research results were published in the journal New Phytologist.

http://www.ecns.cn/2018/03-10/295245.shtml

 

[Galactic Penguin SST]

Construction of gravitational wave telescopes in Tibet underway

March 13, 2018

China is under smooth progress towards the world's highest altitude gravitational wave telescopes in Tibet Autonomous Region to detect the faintest echoes resonating from the universe, a project insider disclosed.

The main part for the first stage of the "Ngari plan", which was launched by China in March 2017 to eyeball the Big Bang cosmic waves at Ngari, Tibet, is almost completed, Zhang Xinmin, chief scientist of the project said on the sidelines of the ongoing first session of the 13th National Committee of the Chinese People’s Political Consultative Conference (CPPCC).

The project will start operations in 2020 and observation results will arise in 2022, added Zhang, a senior researcher at the Institute of High Energy Physics in the Chinese Academy of Sciences (CAS).

At the first stage of the two-phased project, a telescope code-named Ngari No.1 would be constructed at 5,250 meters above sea level to enable the first measurement of primordial gravitational waves in the northern hemisphere, according to the scientist.

The first telescope is expected to be installed at the end of 2019 and operational in 2020, added Zhang, also a member of the 13th CPPCC National Committee.

The second stage, according to him, involves a series of telescopes, code-named Ngari No. 2, to be located at an altitude of about 6,000 meters, to realize more accurate measurement of the waves.

Chinese scientists are now working on design of the first telescope with a team of Stanford University, and they would cooperate more in the future, he said.

The primordial gravitational waves, different from gravitational waves produced by motions and evolution of the heavenly bodies, were generated by the first tremors of the Big Bang.

Detection of the primordial gravitational waves is of great significance to studying the origin and evolution of the universe, said Zhang.

Ngari is considered as one of the world's four best places for astronomers to gaze into the faint echoes from the earliest days of the universe given its thin air, clear skies and minimal human activity.

The other three spots to detect the tiny twists in cosmic light are Atacama Desert, Chile and Antarctica in the southern hemisphere, as well as Greenland in the northern hemisphere.

The Ngari observatory, once constructed, will be the first of its kind in the northern hemisphere for China to carry out experiments regarding detection of primordial gravitational waves.

By then, the Ngari observatory, alongside the existing South Pole Telescope and the facility in Chile’s Atacama Desert, will cover both the northern and southern hemispheres.

Both space exploration and ground-based research have been employed by China to gaze into the remote universe.

The telescope in Ngari and FAST, a 500-meter aperture spherical radio telescope in southwest China’s Guizhou province, dedicate to probing waves from ground-based research facilities, while the Taiji and Tianqin projects, proposed by CAS and Sun Yat-sen University respectively, focus on detection by launch of satellites.

Spoiler: Links

https://defence.pk/pdf/attachments/...7/?temp_hash=bb2e794117054a3680c845311932f080
http://en.people.cn/NMediaFile/2018/0313/FOREIGN201803131027000353274509026.jpg
http://en.people.cn/n3/2018/0313/c90000-9436318.html

▲ The Ngari Observatory

Spoiler: Links

https://defence.pk/pdf/attachments/...8/?temp_hash=bb2e794117054a3680c845311932f080
http://en.people.cn/NMediaFile/2018/0313/FOREIGN201803131027000592914584468.jpg
http://en.people.cn/n3/2018/0313/c90000-9436318.html

▲ The Ngari Observatory at night

http://en.people.cn/n3/2018/0313/c90000-9436318.html

 

[cirr]

Chinese scientists develop bionic nanodevice to combat breast cancer

2018-03-15 09:08 Xinhua Editor: Gu Liping

Chinese scientists have developed a bionic nanodevice that could provide a strategy for targeted therapy for metastatic breast cancer.

Scientists from the Shanghai Institute of Materia Medica under the Chinese Academy of Sciences have constructed a nanodevice, named rHS-DTX, which has a red blood cell coating and can be sent into the body. Their research was published in Advanced Functional Materials on March 1.

The device has been tested on metastatic breast cancer in mice, and achieved a tumor inhibiting rate of 98.2 percent and a lung metastasis suppression rate of 99.6 percent. No severe toxicity was observed in the major organs and blood of the mice.

Breast cancer is the most common cancer in women worldwide, and there is currently no cure for metastatic breast cancer.

Chemotherapy is still the main treatment for primary tumors and metastasis of breast cancer, but it is not able to effectively differentiate cancer cells from normal cells. The new nanodevice has shown a high efficacy in suppressing targeted tumors.

China has recently seen an increase in research applying nanotechnology to medical treatments.

 

[JSCh]

Chinese, American scientists find new way to accelerate wound healing
Source: Xinhua| 2018-03-15 03:36:36|Editor: yan


WASHINGTON, March 14 (Xinhua) -- Chinese and American scientists identified a new immune target that may speed up the healing of skin wounds.

The study, published on Wednesday in the journal Science Translational Medicine, has found that a molecular signaling pathway helps to regulate the small, membrane-surrounded structures released by cells called extracellular vesicles from connective tissue stem cells.

The vesicles, containing the interleukin-1 receptor antagonist or IL-1RA, a kind of cytokine, can promote rapid wound healing.

It has shown that vesicles produced by gum connective tissue stem cells released larger amounts of IL-1RA in wounded gum tissue than vesicles produced by skin tissue stem cells in wounded skin, which might help explain why gum wounds in mammals heal more rapidly than skin wounds.

Led by Kou Xiaoxing, a stomatologist with Peking University School and Hospital of Stomatology in Beijing and visiting researcher at University of Pennsylvania School of Dental Medicine, the team injected Anakinra, the FDA-approved medicine of IL-1RA which is used to treat rheumatoid arthritis, into mouse gum and skin wounds.

They found that the drug significantly accelerated wound healing compared to control mice.

Kou told Xinhua that "IL-1RA can inhibit inflammation caused by interleukin-1, which can improve the healing. Inflammation leads to progression of many diseases including rheumatoid arthritis, but they have different pathogenesis."

Small extracellular vesicles containing IL-1RA are also successful in speeding up the delayed wound healing process that occurs in diabetic mice, they have found.

 

[JSCh]

Public Release: 23-Jan-2018
A new family of aerodynamic configurations of hypersonic airplanes
Science China Press

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This is a principle test model (left) and an artist concept for future applications (right) of HIACs. ©Science China Press

Hypersonic vehicles, which flight at Mach numbers lager than five (flight velocity more than 6000 km/h), will serve as a more convenient and efficient transport tool than present subsonic airplanes for long-distance journeys in future. Typically, it only takes a couple of hours from Beijing to New York. Recent interest in these vehicles has grown intensively, and various types of innovative designs have been proposed and studied.

Despite entering the age of hypersonic flight, there still exist many problems to resolve. How to design an advanced aerodynamic configuration is one of them. Prof. Kai Cui, Dr. Yao Xiao, Dr. Ying-Zhou Xu, and Dr. Guang-Li Li from State Key Laboratory of High Temperature Gas Dynamics, Institute of Mechanics, Chinese Academy of Sciences tried to tackle this problem in a long time. After more than seven years investigation, they first proposed a family of innovative configurations named "Hypersonic I-shaped Aerodynamic Configurations". Their work was published as the cover article of SCIENCE CHINA Physics, Mechanics & Astronomy (2018, 61(2), 024722).

In general, there are at least three objectives in designing an aerodynamic configuration, the high lift to drag ratio (L/D), the high volumetric efficiency and the high lift coefficient. Designers always take the high L/D during the cruise state as the primary goal because the flight range is linearly proportional to the L/D according to the famous Breguet's equation. In addition, a vehicle should provide sufficient space to contain equipments, passengers and cargoes as many as possible. Furthermore, the aerodynamic lift coefficient should be enhanced in whatever way possible. This is because a vehicle with high lift may elevate the vehicle to a high altitude where the aero-thermal environment is efficiently improved owing to the low atmosphere density.

Unfortunately, it is difficult to obtain a high L/D for a generic configuration due to the presence of strong shock wave drag and massive viscosity in the hypersonic regime. Moreover, there exist strong contradictions among the L/D, the volumetric efficiency and the lift coefficient. Among the existing configurations, the waverider has been deemed the most promising because the containment of flow beneath the vehicle results in a high pressure being exerted on the lower surface. Yet a pure waverider with high L/D is always too thin to provide enough volume for fuel and payloads. Typically, the volumetric efficiency of the viscous optimized waverider is lower than 0.12. Although the freestream upper surface of a pure waverider can be morphed to an upwarp to enlarge the volume, but this canopy actually forms a compression surface on the upper part of the vehicle, which leads to an increase in both the aerodynamic drag and the negative lift, causing an overall reduction in L/D.

To aim at enhancing the aerodynamic performance of hypersonic aircraft with large volume requirements, a new concept that called high-pressure capturing wing (HCW) was first proposed by Kai Cui et al. Unlike generic configurations, an extra wing called the HCW is attached to the top of an upwarp airframe. Based on the shock wave compression theory, the high-pressure airflow compressed by the upper surface of the vehicle acts on the HCW when it flies in the hypersonic regime. Therefore, the aerodynamic lift significantly augments on the vehicle with only a small increase in drag, producing a correspondingly high increase in its L/D. Furthermore, such a concept particularly fits for vehicles with large volumes because the lift produced by the HCW increases with the increase of the compression angle in the upwarp.

Expanding on the philosophy of HCWs, a family of novel configurations is proposed in this letter. There are two lift surfaces in this configuration. The lower surface is a common compression surface, while the upper one is designed according to the idea of HCWs. The parts between the two wings are the airframe and the attachment struts. Because the cross-section of the configuration appears like the letter "I", it is thus named "Hypersonic I-shaped Aerodynamic Configuration (HIAC)".

In order to validate the advantages of HIACs, a test model with the volumetric efficiency 0.175 was generated as a typical example. Moreover, the leading edge profiles of both the low wing and the HCW were optimized by combined using the computational fluid dynamics, the design of experiments method, the surrogate models method, and the genetic algorithm. Subsequently, a numerical simulation work was carried out to evaluate the aerodynamic performances of the model. The results show that both the L/D and the lift coefficient drastically improve benefiting from the innovative configuration. The maximal L/D values at Mach number 5 to 7 are more than 4.5, while the increased percentages of corresponding values of the lift coefficient are about 60% comparing with generic configurations.

In the present study, only the profiles of the leading edges were taken as design variables of the optimization. The aerodynamic performances of the configuration may be further enhanced if the surface shape of the HCW is considered as optimization variables. The authors believe their present study will promote further research in the aerodynamic design of high-speed configurations, which may ultimately offer a new candidate for hypersonic flight vehicles.

###​

See the article: K. Cui, Y. Xiao, Y. Z. Xu, G. L. Li, "Hypersonic I-shaped aerodynamic configurations" SCIENCE CHINA Physics, Mechanics & Astronomy 61(2), 024722(2018); doi: 10.1007/s11433-017-9117-8

http://engine.scichina.com/publisher/scp/journal/SCPMA/61/2/10.1007/s11433-017-9117-8?slug=full text https://link.springer.com/article/10.1007/s11433-017-9117-8
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A new family of aerodynamic configurations of hypersonic airplanes | EurekAlert! Science News

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China builds world's fastest wind tunnel to spur spaceplane development
Source: Xinhua| 2018-03-19 23:01:59|Editor: Mu Xuequan

BEIJING, March 19 (Xinhua) -- China is building the world's fastest hypersonic wind tunnel to help with the development of spaceplanes.

"The 265-meter-long tunnel can be used to test hypersonic aircraft that can travel at speeds of up to Mach 25 (30, 625 kph), 25 times the speed of sound," Han Guilai, a researcher with China's State Key Laboratory of High Temperature Gas Dynamics of the Chinese Academy of Sciences (CAS), told China Central Television over the weekend.

Han said the current wind tunnel could simulate flights ranging from Mach 5 to 9. Researchers from CAS in Beijing have successfully tested one hypersonic plane in a wind tunnel at such speeds.

The research was published in the journal "Science China: Physics, Mechanics & Astronomy" in February. It unveiled the "I Plane" model, which is capable of transporting people and payloads from Beijing to New York within two hours, beating any commercial airline flight.

Wind tunnels move air around objects, making it seem like the objects are really flying. Spacecraft engineers use them to test ideas for various spacecraft designs. Long after the design work is finished, wind tunnels help make spacecrafts better and safer.

The new tunnel will help China to take the lead on wind tunnel building, though competition from other countries is still fierce, according to Han.

"The new tunnel will aid the engineering application of hypersonic technology by duplicating the environment of extreme hypersonic flights. Once issues are discovered during these ground tests, they will be ironed out before test flights begin," Han said.

 

[onebyone]

China is building the world's fastest hypersonic wind tunnel to test hypersonic aircraft that can travel at speeds of up to 25 times the speed of sound

 

[JSCh]

Chinese scientists analyze human brain's "CPU"
Source: Xinhua| 2018-03-20 20:46:15|Editor: pengying


BEIJING, March 20 (Xinhua) -- Chinese scientists have analyzed the developmental landscape of the human prefrontal cortex (PFC), considered the CPU of the human brain, to get a better understanding of the organ.

Scientists from the Institute of Biophysics of the Chinese Academy of Sciences (CAS), Peking University as well as Capital University of Medical Sciences applied single-cell transcriptional profiling to identify cell types in the developing human PFC and their developmental features. Their research was published online in the journal Nature on March 14.

The PFC is one of the most important brain regions. It contains billions of cells and serves as the center of advanced intellectual activity, such as memory, cognitive ability, decision making and social behavior.

According to Professor Wang Xiaoqun from CAS, there is a need for detailed knowledge of the development of the PFC, since disturbances or failures of PFC development may contribute to several cognitive deficits seen in patients with neurodevelopmental disorders, such as intellectual disabilities, autism spectrum disorders and schizophrenia.

"Although we have known that the brain has a variety of functions, we have little knowledge about the different cell types and the cell composition, which makes it hard for us to understand how the brain develops advanced cognitive function," Wang said.

In order to systematically analyze the cellular basis and molecular regulation of the PFC, scientists traced the molecular features of cells in the PFC during human brain development at gestational weeks 8 to 26.

They analyzed more than 2,300 single cells and identified 35 subtypes of cells in six main classes. They also traced their development process.

The research will provide a powerful tool for investigating the mechanisms behind neurological diseases related to abnormal structure or dysfunction of the PFC and for exploring potential therapies.

According to Wang, the ongoing cell-census projects of "The BRAIN Initiative" in the United States mainly focus on the rodent brain atlas.

"We focus more on identifying and characterizing neuronal and non-neuronal cells in the human brain, which will directly help understand the molecular and cellular mechanism of human brain disorders," Wang said.

China has seen intensified research in brain science to advance basic understanding of the brain as well as to find treatments for brain-related disease.

Wang hopes that the Chinese government will attach more importance to research on brain science and offer more support. He also said that interdisciplinary research and teamwork among people from different disciplines are vital in advancing brain science study.

"In the research, another team member, Tang Fuchou from Peking University, is an expert on single-cell sequencing in stem cell biology, and we have complementary advantages, which makes research go more smoothly," Wang said.

"Research on the human brain atlas needs interdisciplinary collaboration from different areas such as cell biology, neuroscience and computer science. We hope to see more labs focusing on the interdisciplinary study of brain science," Wang added.

Currently, Wang and his team are working on the non-neuronal cells in the human brain, which make up about half the total volume of the brain and spinal cord.

"We hope to figure out how those cells work together with neuronal cells and further explore the mystery of the human brain," Wang said.

Suijuan Zhong, Shu Zhang, Xiaoying Fan, Qian Wu, Liying Yan, Ji Dong, Haofeng Zhang, Long Li, Le Sun, Na Pan, Xiaohui Xu, Fuchou Tang, Jun Zhang, Jie Qiao & Xiaoqun Wang. A single-cell RNA-seq survey of the developmental landscape of the human prefrontal cortex. Nature (2018). DOI: 10.1038/nature25980​

 

[JSCh]

China takes 2nd place for WIPO patent filings
By Camilla Tenn | China Daily | Updated: 2018-03-22 07:56

China overtook Japan to become the second-largest source of international patent filings via the World Intellectual Property Organization's Patent Cooperation Treaty in 2017, despite strong growth in Japanese companies' use of the system, according to the UN agency.

WIPO said in a news release that at current trends, China is projected to overtake the United States - which currently files the most international patents annually - within three years as the largest source of patent applications via the PCT.

"This rapid rise in Chinese use of the international patent system shows that innovators there are increasingly looking outward, seeking to spread their original ideas into new markets as the Chinese economy continues its rapid transformation," said WIPO Director General Francis Gurry.

"This is part of a larger shift in the geography of innovation, with half of all international patent applications now originating in East Asia."

Last year, US-based patent applicants filed 56,624 applications using the PCT, followed by 48,882 from China and 48,208 from Japan. Germany and South Korea ranked No 4 and No 5, with 18,982 and 15,763 applications, respectively.

Two Shenzhen-based Chinese technology companies were the top filers via the PCT in 2017.

Huawei was the largest and ZTE took second place, followed by the US-based Intel, Japan's Mitsubishi and Qualcomm, also from the US.

China's LE Holdings burst into the international top 20, rising 2,257 spots from last year with 1,397 applications filed using the PCT in 2017. Tencent, Yulong Telecommunication, Oppo and Xiaomi all entered the top 50 last year.

In trademark filings via WIPO's Madrid system, China saw the fastest growth among the top 15 origins with a 36.3 percent year-on-year increase, followed by Russia with 23.9 percent, South Korea with 9.8 percent and the United Kingdom with 9.3 percent.

Both China and Russia recorded their second consecutive year of double-digit growth.

For patent, trademark and industrial design applications using WIPO's filing services, 2017 was a record year, according to the organization, marking the eighth consecutive year of growth for all three of its filing systems.

Inventors from around the world filed 243,500 international patent applications via the PCT in 2017, 4.5 percent more than the previous year, driven by strong growth from China and Japan.

Demand grew by 5 percent year-on-year for WIPO's Madrid system, which saw 56,200 trademark applications.

The number of industrial designs WIPO handled grew by 3.8 percent year-on-year to reach 19,429.