News on China's scientific and technological development.

Chemical sensing: Collapsing for chirality



"Chemical sensing: Collapsing for chirality
NPG Asia Materials featured highlight | doi:10.1038/asiamat.2010.147
Published online 13 September 2010

An organometallic gel undergoes a dramatic change in structure in the presence of molecules with specific structural configurations.


Fig. 1: Electron microscopy images of the dried gel (left) and solution (right) forms of binaphthol–copper.

From Ref. 1. Reproduced with permission. © 2010 ACS

One of the fastest ways to qualitatively analyze chemical reactions is visually; it’s hard to mistake an abrupt color change or the appearance of new precipitates in a solution. These methods, however, are restricted to only a few processes, and normally do not provide an understanding of advanced phenomena such as chirality — the tendency for certain compounds to occur in mirror-image forms. The two chiral forms, called left- and right-handed enantiomers, can have very different properties, such as pharmaceutical effects. Yet physically, the two forms can only be distinguished through specialized and time-consuming techniques.

Researchers led by Xiao-Qi Yu from Sichuan University in China and Lin Pu from the University of Virginia in the USA[1] have now discovered an innovative system that allows chirality to be detected visually. Their method involves a gel that collapses when it interacts with enantiomers of opposite ‘handedness’.

Molecular gels have recently gained attention as sensing platforms because their structures at the boundary between liquid and solid states are extremely responsive to changes in their environment. Originally, Yu, Pu and their colleagues had been studying the reaction between a derivative of binaphthol — a chiral aromatic compound — and copper to develop a fluorescent sensor. But when the binaphthol derivative was mixed with copper ions in an ultrasonic bath, an opaque green gel quickly formed. The formation of such a gel was unexpected because ultrasound usually breaks up gel networks.

The team found that their gel consisted of a stabilized three-dimensional network (Fig. 1). Because chiral compounds such as binaphthol act differently when mixed with other chiral substances, the researchers decided to investigate the gel’s stability towards chiral amino alcohols — molecules known to displace copper from aromatic binding sites.

Pu and his colleagues found that the binaphthol–copper gel was particularly sensitive to enantiomer type. When the gel and the amino alcohol had the same chirality, the gel remained stable even after ultrasonication. If the chiral sites were different, however, the gel collapsed as soon as it was agitated.

The researchers are now working on fully understanding the mechanism behind their collapsible detection system. “This will allow us to develop new gel materials for recognition of diverse chiral molecules with rapid assays,” says Pu.

Reference

1. Chen, X.,1 Huang, Z.,1 Chen, S.-Y.,1 Li, K.,1 Yu, X.-Q.1 & Pu, L.2* Enantioselective gel collapsing: A new means of visual chiral sensing. J. Am. Chem. Soc. 132, 7297 (2010). | article

Author affiliation

1. Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China
2. Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, USA
*Email: [email protected]

This research highlight has been approved by the author of the original article and all empirical data contained within has been provided by said author."


Color-change in a chemical reaction is a very useful tool in chemistry. Scientists rely on color-change in titration experiments all of the time. The latest discovery, from Chinese scientists in visually detecting the "handedness" of an enantiomer through "chemical sensing: collapsing for chirality," is a great boon to all scientists.


Titration endpoint color change

China has six Yuanwang space tracking ships


"Zhai Zhigang waves the Chinese flag after emerging from the Shenzhou 7 spaceship."

China has a total of 6 Yuanwang space tracking ships. For manned spaceflights, China deploys at least four Yuanwang ships. For unmanned space programs like Chang'e II, China deploys only three Yuanwang ships.



"Another two Yuanwang-class vessels were launched in Shanghai in early 2007.[1]

Pictures of Yuanwang 6 were published as it has been revealed that both Yuanwang 5 and the newly commissioned ship would be on duty for the Shenzhou 7 mission.[2]

During the Shenzhou spacecraft flights, the four ships are positioned with:[3]

* Yuanwang 1 in the Yellow Sea
* Yuanwang 2 about 1500 km (about 900 statute miles) southwest of French Polynesia
* Yuanwang 3 off the Namibian coast
* Yuanwang 4 off the coast of Western Australia in the Indian Ocean"

-----

I watched the Mandarin interview with the director and another important program manager of Chang'e II. They both look like they are in their early to mid-30s.

The First Chinese- Nobel- Prize Winner: Yang Zhenning



"The First Chinese- Nobel- Prize Winner: Yang Zhenning


Yang Zhenning (Chen-Ning Yang) is the first Chinese-born physicist to win the Nobel Prize.

Yang Zhenning (Chen-Ning Yang) is a Chinese-American physicist, who has worked on statistical mechanics and symmetry principles. He received the Nobel Prize in Physics in 1957 at the age of 35, with Li Zhengdao (Tsung-Dao Lee), to become the first two Chinese Nobel-Prize winners.

Yang is also well known for his collaboration with Robert Mills in developing a gauge theory of a new class. Such "Yang-Mills theories" are now a fundamental part of the Standard Model of particle physics.

Yang Zhenning's Life

Yang Zhenning was born on September 22, 1922, in Hefei of East China's Anhui Province. Yang was brought up in a peaceful and academically inclined atmosphere of the campus of Tsinghua University in Beijing, where his father was a Professor of Mathematics.

When Yang was very young, he demonstrated a talent for mathematics. However, his father didn't give him any special training in mathematics, instead, he employed a history teacher for Yang. From this teacher, Yang gained much knowledge of Chinese history. As a middle school student, Yang could recite all the texts of Mencius, a famous Confucian scholar who was second only to Confucius himself.

In 1937, when the Anti-Japanese War began (known as WWII in the West), Yang and his family went back to their hometown of Hefei. After the Japanese troops entered Nanjing, Yang and his family spent time in Hankow and Hong Kong (both in East China), and Hanoi (today's Hainan Provincein South China); before finally arriving at Kunming of Southwest China's Yunnan Province in March 1938, where Yang furthered his study.

In 1942, Yang Zhenning received his Bachelor of Science degree from Kunming's National Southwest Associated University. Two years later, he studied for his Master of Science degree with a full scholarship at Tsinghua University.

Yang Zhenning attended the University of Chicago on a Tsinghua University Fellowship in January 1946. There he studied for his Ph.D. with Edward Teller and after receiving it in 1948, remained for a year as an assistant to Enrico Fermi, a famous physicist. In 1949 he moved to the Harvard-affiliated Radcliffe's Institute for Advanced Study and in 1965 to New York's Stony Brook University, where he worked until 1999.

He has been elected a Fellow of the American Physical Society and the Academia Sinica, and was awarded an honorary doctorate by Princeton University in 1958.

In 1950, Yang Zhenning married Du Zhili, a former student of his, and had two sons and a daughter.

In 1999 Yang Zhenning returned to Tsinghua University following his retirement from Stony Brook University. His wife died in the winter of 2003. In 2005, at the age of 82, Yang Zhenning married a 28-year old woman, who is studying for a master degree at Guangdong University.

Great Contributions

Since from almost his earliest days as a physicist, Yang Zhenning has made significant contributions to the theory of the weak interactions--the forces long thought to cause elementary particles to disintegrate.



By 1953 it was recognized that there was a fundamental paradox in this field since one of the newly discovered mesons--the so-called K meson--seemed to exhibit decay modes into configurations of differing parity. Since it was believed that parity had to be conserved, this led to a severe paradox.

After exploring every conceivable alternative, Li Zhengdao and Yang Zhenning were forced to examine the experimental foundations of parity conservation itself. In early 1956, they discovered that, contrary to what had been assumed, there was no experimental evidence against parity non-conservation in the weak interactions. The experiments that had been done, it turned out, simply had no bearing on the question.

They suggested a set of experiments that would settle the matter, and, when these experiments were carried out by several groups of people over the next year, large parity-violating effects were discovered. In addition, the experiments also showed that the symmetry between particle and antiparticle, known as charge conjugation symmetry, is also broken by the weak decays.

In addition to his work on weak interactions, Yang Zhenning, in collaboration with Li Zhengdao and others, carried out important work in statistical mechanics -- the study of systems with large numbers of particles -- and later investigated the nature of elementary particle reactions at extremely high energies.

Starting from 1965, Yang Zhenning was the Albert Einstein professor at the Institute of Science, State University of New York at Stony Brook, Long Island. During the 1970s he was a member of the board of Rockefeller University and the American Association for the Advancement of Science respectively, and from 1978, of the Salk Institute for Biological Studies, in San Diego, California.

He was also on the board of Ben-Gurion University, in Beersheba, Israel. He received the Einstein Award in 1957 and the Rumford Prize in 1980. In 1986 he received the Liberty Award and the National Medal of Science."



"Chinese state councilor visits Chinese-American Nobel laureate
10:37, October 02, 2010

Chinese State Councilor Liu Yandong visited Chinese-American Nobel physics laureate Yang Chen-ning at Tsinghua University in Beijing on Friday.

Friday is Yang's 88th birthday and Liu extended her congratulations to Yang and praised his years of efforts in promoting China's education.

Yang had made important contributions in fostering young Chinese talent and promoting the country's educational development as well as academic exchanges and cooperation between China and the United States.

His efforts were even more remarkable after 2003 when he returned and settled in China.

Liu discussed with Yang about China's education reform and the Outline of the National Plan for Medium-and Long-term Educational Reform and Development.

Education Minister Yuan Guiren accompanied Liu on the visit.

Source: Xinhua"

Carbon nanotubes: The domino effect



"Carbon nanotubes: The domino effect
NPG Asia Materials research highlight | doi:10.1038/asiamat.2010.158
Published online 27 September 2010

Carbon nanotube structures can be mechanically oscillated via a temperature-induced ‘domino’ process.


Fig. 1: Temperature changes induce waves of domino-like, reversible structural transformations in carbon nanotubes.

Adapted from Ref. 1. Reproduced with permission. © 2010 ACS

Ultra-tiny heat engines that convert thermal energy into mechanical energy may soon be on the horizon according to a computer simulation study from China[1]. Tienchong Chang and Zhengrong Guo from Shanghai University report that carbon nanotubes can be changed from their usual circular shapes into collapsed, flattened structures through a domino-like wave that propagates along the length of the tube. This transformation can be reversed by raising the temperature; setting the stage for multifunctional oscillators that operate at molecular levels.

Calculations by Chang previously showed that the circular structures of large single-walled carbon nanotubes are only meta-stable: energetically, the tube is most stable when it collapses and lies flat. Transitioning to this fallen state, however, requires overcoming a significant energy barrier. “If we view each carbon ring along the nanotube as a domino, then the stable state corresponds to a fallen-down system, while the meta-stable circular state is when the domino is standing up,” says Chang. “A standing domino cannot fall down by itself — it needs an external stimulus.”

The researchers found that clamping down on one end of the nanotube provided the necessary impetus to release the material’s potential energy; sequentially knocking the carbon structure down like a wave of tumbling dominoes. The next challenge facing the team was how to control this effect.

Molecular dynamic simulations on a 4.3 nm-wide tube with one end shut and the other propped open revealed that temperature could modify the material’s stable state. After the tube structure toppled over at room temperature, raising the temperature to over 600 °C reversed the transformation: the collapsed zone shrank along the tube as the carbon rings returned to their upright, circular shapes (Fig. 1).

Additional simulations showed that the critical temperature needed to induce the conversion between the two states was a linear function of tube diameter, with larger tubes needing higher temperatures to leave the collapsed state. The speed of the propagating domino waves, which can reach 800 m/s, could also be adjusted through subtle temperature variations.

Chang notes that the highly tunable nature of the temperature-induced domino effect opens the door to many novel applications, including rechargeable ‘nanoguns’ that can controllably expel molecules or particles from the tubes.

Reference

1. Chang, T.* & Guo, Z. Temperature-induced reversible dominoes in carbon nanotubes. Nano Lett. 10, 3490 (2010). | article

Author affiliation

Shanghai Institute of Applied Mathematics and Mechanics, Institute of Low Dimensional Carbon and Device Physics, Shanghai University, Shanghai 200072, China
*Email: [email protected]

This research highlight has been approved by the author of the original article and all empirical data contained within has been provided by said author."

Electrochemistry: Long live the lithium battery



"Electrochemistry: Long live the lithium battery
Published online: 1 September 2010 | doi:10.1038/nchina.2010.99
Felix Cheung

Eliminating oxygen in the electrolyte prolongs the life of a lithium-ion battery

Original article citation
Luo, J. Y., Cui, W. J., He, P. & Xia, Y. Y. Raising the cycling stability of aqueous lithium-ion batteries by eliminating oxygen in the electrolyte. Nature Chem. doi:10.1038/nchem.763 (2010).

Click to expand...

© (2010) istockphoto.com/Ingenui

Non-aqueous electrolytes of traditional lithium-ion batteries use highly toxic and flammable organic solvents, which can be dangerous if used improperly. Using aqueous electrolytes can avoid this problem, but an aqueous lithium-ion battery typically loses half of its battery capacity after 100 charge–discharge cycles. Yongyao Xia and co-workers at Fudan University in Shanghai[1] have now devised several strategies to prolong the lifetimes of such aqueous batteries.

A battery loses capacity when its electrodes oxidize and internal resistance increases. The researchers analysed the stability of electrode materials in aqueous electrolytes and found that negative electrodes react with water and oxygen during discharge, which causes capacity fading upon charge–discharge cycling. They improved the stability of aqueous lithium-ion batteries by eliminating oxygen, adjusting the pH of the electrolyte and using carbon-coated electrode materials. The capacity retention of their batteries was over 90% after 1,000 cycles.

By implementing these strategies, aqueous lithium-ion batteries may offer an energy-storage system with high safety, low cost and long lifetime.

The authors of this work are from:
Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Institute of New Energy, Fudan University, Shanghai, China.

Reference

1. Luo, J. Y., Cui, W. J., He, P. & Xia, Y. Y. Raising the cycling stability of aqueous lithium-ion batteries by eliminating oxygen in the electrolyte. Nature Chem. doi:10.1038/nchem.763 (2010). | Article"

some forumer here look down on Chinese military electronic capacity and always use the word copy or not as advanced as the Russian , Surprise surprise Here the observation of real expert in the defense electronic . the former student has bested their teacher



In the 1990s, when the Russian defence was in danger of drying up and closing its doors due to an almost complete collapse in any funding from their own government, it was China that saved the day. China bought billions in military hardware from Russia, but it also sent its engineers, designers and technicians to study inside of Russian industry to learn how the weapons it was purchasing had been developed in the first place.

This transfer of technological know-how, plus some enormous investments by the Chinese military into its state-owned industries (what more than one Russian has referred to as “uncontrolled and rampant modernisation”) has produced a defence electronics industry that far outstrips the size and capacity of that which existed in Russia when Chinese industry first began their cooperation with Moscow in the early 1990s.

Today the former students (the Chinese) have become the masters. Chinese industry now has the ability to produce components that the Russian electronics industry (after almost two decades of no investment by their government) is no longer capable of either designing or manufacturing. The initial failure rates on the production of transmit/receive (T/R) modules for the Active Electronically Scanned Array (AESA) radars being designed for the Mikoyan MiG-35 and the Sukhoi T-50/PAK-FA 5th-generation fighter, for example, were so high that it would have bankrupted any western firm involved in a similar programme.

Not surprisingly, this year’s CIDEX show saw groups of Russian specialists going through the halls and looking for components that they could source out of China to be utilised in Russian-designed weapon systems. Russian specialists will point out that they are now at a huge disadvantage to the Chinese in two very significant respects.

One is that the commitment by the central government in resources to the defence electronics sector is both sustained and serious. “They can take a field where there is nothing but flat land and wild grass,” said one Russian company representative, “and the next thing you know there is a full-blown factory or design centre there turning out a world-class product.”




Chinese firms are now producing components that far surpass that of the Russian firms they learned their skills from in the early 1990s.


The other advantage to China is the unfortunate reality of actuarial tables. Younger scientists and engineers who are needed in Russia to form the next-generation of weapons designers are leaving the nation in droves. A few years ago the Russian Foreign Intelligence Service (SVR) estimated that 70,000 scientists and specialists from Russian defence institutes and military-industrial complex enterprises had left the country.

A documentary on the subject produced by Moscow’s NTV stated “the nuclear physicists, experts in electronic equipment, virologists and biotechnologists did not leave Russia empty-handed. They took secrets with them and presented their former foes with the weapons they had themselves developed.”

The documentary went on to claim “according to CIA data, in the first half of the 1990s thousands of Soviet specialists in the field of nuclear and missile technology left for the Middle East. They worked there in violation of the treaty on non-proliferation of weapons of mass destruction and the MTCR. From the Arzamas-16 centre several people went to work in Iraq. Russian scientists worked in Iran and Libya. Forty nuclear scientists immigrated to Israel. Thousands of Russian specialists in the field of nuclear and missile technologies developed programmes to improve armaments in China. Our scientists are willing to work anywhere they are paid.”

The consequence is that whereas the age of the average defence industrial scientist or engineer in China is about 30 and around 40 in the US – it is 50 years or more in Russia. China’s industry is growing and advancing, while Russia’s will effectively be dying off before too long

Hendrik_2000 said:

some forumer here look down on Chinese military electronic capacity and always use the word copy or not as advanced as the Russian , Surprise surprise Here the observation of real expert in the defense electronic . the former student has bested their teacher

Please, Log in or Register to view URLs content!

In the 1990s, when the Russian defence was in danger of drying up and closing its doors due to an almost complete collapse in any funding from their own government, it was China that saved the day. China bought billions in military hardware from Russia, but it also sent its engineers, designers and technicians to study inside of Russian industry to learn how the weapons it was purchasing had been developed in the first place.

This transfer of technological know-how, plus some enormous investments by the Chinese military into its state-owned industries (what more than one Russian has referred to as “uncontrolled and rampant modernisation”) has produced a defence electronics industry that far outstrips the size and capacity of that which existed in Russia when Chinese industry first began their cooperation with Moscow in the early 1990s.

Today the former students (the Chinese) have become the masters. Chinese industry now has the ability to produce components that the Russian electronics industry (after almost two decades of no investment by their government) is no longer capable of either designing or manufacturing. The initial failure rates on the production of transmit/receive (T/R) modules for the Active Electronically Scanned Array (AESA) radars being designed for the Mikoyan MiG-35 and the Sukhoi T-50/PAK-FA 5th-generation fighter, for example, were so high that it would have bankrupted any western firm involved in a similar programme.

Not surprisingly, this year’s CIDEX show saw groups of Russian specialists going through the halls and looking for components that they could source out of China to be utilised in Russian-designed weapon systems. Russian specialists will point out that they are now at a huge disadvantage to the Chinese in two very significant respects.

One is that the commitment by the central government in resources to the defence electronics sector is both sustained and serious. “They can take a field where there is nothing but flat land and wild grass,” said one Russian company representative, “and the next thing you know there is a full-blown factory or design centre there turning out a world-class product.”




Chinese firms are now producing components that far surpass that of the Russian firms they learned their skills from in the early 1990s.


The other advantage to China is the unfortunate reality of actuarial tables. Younger scientists and engineers who are needed in Russia to form the next-generation of weapons designers are leaving the nation in droves. A few years ago the Russian Foreign Intelligence Service (SVR) estimated that 70,000 scientists and specialists from Russian defence institutes and military-industrial complex enterprises had left the country.

A documentary on the subject produced by Moscow’s NTV stated “the nuclear physicists, experts in electronic equipment, virologists and biotechnologists did not leave Russia empty-handed. They took secrets with them and presented their former foes with the weapons they had themselves developed.”

The documentary went on to claim “according to CIA data, in the first half of the 1990s thousands of Soviet specialists in the field of nuclear and missile technology left for the Middle East. They worked there in violation of the treaty on non-proliferation of weapons of mass destruction and the MTCR. From the Arzamas-16 centre several people went to work in Iraq. Russian scientists worked in Iran and Libya. Forty nuclear scientists immigrated to Israel. Thousands of Russian specialists in the field of nuclear and missile technologies developed programmes to improve armaments in China. Our scientists are willing to work anywhere they are paid.”

The consequence is that whereas the age of the average defence industrial scientist or engineer in China is about 30 and around 40 in the US – it is 50 years or more in Russia. China’s industry is growing and advancing, while Russia’s will effectively be dying off before too long

Click to expand...

You may find interest in my recent post on the PLAN submarines II thread or you can follow this link >>> Enjoy !

How long can the EU and US play this 1989 embargo card? It is hypocrisy considering the human rights violations of say Saudi Arabia and Israel.The interesting article on the report is the last one.I think this could open the floodgates (albeit on similar technical grounds)to other companies if no action is taken against Sensonor.I would rather see a concerted effort by all to remove it as opposed to it being removed de-facto though.

A Little Help From The EU

One of the few foreign firms that was exhibiting at CIDEX for the first time was the Norwegian electronics manufacturer, Sensonor. The company is offering its products on both the Chinese and Russian military markets. It is one of the leading European firs to offer products based on Micro-Electro-Mechanical Systems (MEMS) technology, and the company representatives said that this was their first show in China.

Sensonor’s MEMS gyroscope components offer the possibility for radically improving the accuracy of Chinese missile systems and precision-guided munitions. The central component is the STIM202 Butterfly gyro, which is a 55-gram miniature module that replaces previous-generation fibre-optic, ring laser and mechanical gyros.

The STIM202 is based on single-crystal silicon technology. It can be configured in 1, 2 or 3 axes capability and offers 24-bit resolution plus an RS422 bit rate like the components made by their Chinese competitors at Kotel. Company engineers claim that “the STIM202 is so small and light that the designers of a missile system can use two of the modules to provide the weapon’s on-board guidance module with back-up redundancy, which was never a possibility with previous-generation guidance components.”


Norway’s Sensonor has the market for selling MEMS based guidance equipment all to itself in China. The US and other EU firms cannot compete here. This technology could profoundly enhance the accuracy of all Chinese-produced PGM.


There are a number of firms worldwide producing components based on this type of technology, but the rest of them are barred from doing business in China due to the Tiananmen Square arms embargo. However Sensonor claim they can do business in China because “there is no ITAR content to our product.”

“We almost have to thank the US government for forbidding American firms from offering this product in China,” said one Sensonor engineer, “because the prohibition has more or less left this market completely open for us without any US or other competition.”

If the Sensonor technology is purchased by Chinese industry in significant numbers, their missiles and other guided weapons will achieve levels of performance and accuracy comparable to their western counterparts, but at a much lower total system cost. Even though Kotel in China are already producing a similar product, the people from Sensonor said that they are not worried about their product being reverse-engineered and illegally copied.

“This is a complex technology and it requires significant amounts of investment in industrial production equipment and years of experience to be able to produce these components on a cost-effective basis. This does not lend the technology to being easy to duplicate.”

Why selling this product into China is not considered a violation of the EU arms embargo on the PRC is unknown. Having no ITAR content may be one issue, but the significant increase it will bring to the accuracy of Chinese weaponry certainly violates the spirit – if not the letter – of the EU embargo.

The fact that this Norwegian firm was one of the only foreign companies offering a new product shows just how technologically sophisticated China’s defence electronics sector has become. There appears to be little that they cannot do on their own, and what few technologies they cannot develop on their own seems to become more and more readily available despite international sanctions that should prevent them from being able to purchase it.

speaking of MEM-INS, around 5 years ago, a brief summary of new tecnology develop in Chinese lab was MEM-INS, this brief statement was posted in the chinese web site.
ironic, Boeing aircraft was fine half million $ by the pentagon, when boeing aircraft sold to China included MEM-ins.
BTW, do spike ,hellfire and javelin ATM contain MEM-ins?

zoom said:

Why selling this product into China is not considered a violation of the EU arms embargo on the PRC is unknown.

Click to expand...

.........it could be because Norway is not part of the EU?

Don't get me wrong. Norway makes sure not to directly hurt the interests of its EU partners, so I'm guessing they won't sell any technology that was acquired from an EU member. Indigenous technology is a different matter.

From what I've gathered from media reports here in Norway, this country remains one of the most militarily friendly countries in Europe with regards to trade and contacts with China. I still remember when a delegation from Chinese military intelligence visited our unit during the NATO exercise Cold Response '07 and was allowed to take a peek at our artillery and ask some basic questions about how it functioned. The visit was top secret of course.