Experimental and numerical study on energy dissipation in freely cooling granular gases under microgravity

Energy dissipation is one of the most important properties of granular gas, which makes Its behavior dltterent trom that of molecular gas. In this work we report our investigations on the freely-cooling evolution of granular gas under microgravity in a drop tower experiment, and also conduct the molecular dynamics （MD） simulation for comparison. While our experimental and simulation results support Haff＇s law that the kinetic energy dissipates with time t as E（t） （1 ＋ t/v） 2, we modify ~＂ by taking into account the friction dissipation during collisions, and study the effects of number density and particle size on the collision frequency. From the standard deviation of the measured velocity distributions we also verify the energy dissipation law, which is in agreement with Haff＇s kinetic energy dissipation.

In vivo fiber photometry of neural activity in response to optogenetically manipulated inputs in freely moving mice

In vito fber photometry is a powerful technique to analyze the dy namics of population neurons during fiunctional study of neuroscience.Here,we introduced a detailed protocol for fiber photometry-based calciun reording in freely moving mice,covering from virus injection,fiber stub insertion,optogenetical stimulation to data procurement and analysis.Furthemnore,we applied this protocol to explore neuronal activity of mice latenal-posterior(LP)thalaric nucleus in response to optogenetical stimulation of primary visual cortex(V1)neurons,and explore axon clusters activity of optogenetically evoked V1 neurons.Final confirmation of virus-based protein expression in V1 and precise fber insertion indicated that the surgery procedure of this protocol is reliable for functional calcium recording.The scripts for data analysis and some tips in our protocol are provided in details.Together,this protocol is simple,low-cost,and effective for neuronal activity detection by fiber photometry,which will hep neuroscience researchers to carry out fiunctional and behavioral study in vivo.

THE SPATIAL DISTRIBUTION AND MOMENTS OF CIRCULAR FREELY JOINTED CHAIN

The spatial distribution function and second moments of circular freely jointed chain are derived based on an analytical method. The circular Gauss chain, which is simple for long chains, is compared with the circular freely jointed chain, which is exact for short chains. It is shown that the Gauss chain model predicts a more compact configurational distribution than the exact freely jointed chain. The two chain models, however, become closer to each other when the chain length increases. It is found that the difference of the mean square radius of gyration calculated with these two chain models is a constant, independent of the chain length.

Flying Freely in a Black-and-White World——Young photographer Wen Hengmin

Foreign tourists to Beijing aspire to do three things -?climb the Great Wall, eat Beijing roast duck and visit the Panjiayuan flea market. On weekends, the Panjiayuan market attracts thousands of shoppers, both Chinese and foreign. In one corner a unique stand sells pictures. Displayed on one wall and grouped on a table are dozens of black-and-white photographs of folk customs in simple but elegant frames, just like at a photographic exhibition. Many people -

A novel odor stimulation system in freely moving,behaving animals

Precise and reliable presentation of odorants to animals is crucial for olfactory studies.Although odor stimulation systems in anesthetized or awake,head-fixed animals are well established,temporally precise odor presentation in awake,freely moving animals remains a challenge.Here,we describe a new odor stimulation system which presents odors directly to the nostrils of freely moving mice.The system comprises 3 modules:an odor-delivery module,an odor-generation module,and a control module.The new system is precise and temporally reliable,and odor stimulation can be triggered by specific sniffing phases or other events.Moreover,the system can be combined with neural recordings,such as electrophysiology,and olfactory behavioral tests to investigate how neurons in the brain represent odor information during individual olfactory behaviors.This innovative odor stimulation system may replace traditional stimulation systems:It will enable precise odor presentation in a wide range of olfactory studies in freely moving animals.

Sensing of microparticles based on a broadband ultrasmall microcavity in a freely suspended microfiber

We theoretically design and experimentally realize a broadband ultrasmall microcavity for sensing a varying number of microparticles whose diameter is 2 μm in a freely suspended microfiber. The performance of the microcavity is predicted by the theory of one-dimensional photonic crystals and verified by the numerical simulation of finite-difference time domain and the experimental characterization of reflection and transmission spectra. A penetrating length into the reflectors as small as about four periods is demonstrated in the numerical simulation,giving rise to an ultrasmall effective mode volume that can increase the sensitivity and spatial resolution of sensing. Moreover, a reflection band as large as 150 nm from the reflectors of the microcavity has been realized in silica optical microfiber in the experiment, which highly expands the wavelength range of sensing. Our proposed microcavity integrated into a freely suspended optical fiber offers a convenient and stable method for long-distance sensing of microparticles without the need for complicated coupling systems and is free from the influence of substrates.

Efficiency analysis and optimization of wireless power transfer system for freely moving biomedical implants

In the wireless power transfer system for freely moving biomedical implants,the receiving unit was generally inefficient for the reason that its design parameters including the receiving coil's dimension and receiving circuits' topology were always determined by experiments.In order to build the relationship between these parameters and the total transfer efficiency,this paper developed a novel efficiency model based on the impedance model of the coil and the circuit model of the receiving circuits.According to the design constraints,the optimal design parameters in the worst case were derived.The results indicate that the combination of the two-layered receiving coil and half-bridge rectifier has more advantages in size,efficiency and safety,which is preferred in the receiving unit.Additionally,when the load resistance increases,the optimal turn number of the receiving coil basically keeps constant and the corresponding transmitting current and total efficiency decrease.For 100 Ω load,the transmitting current and total efficiency in the worst case were measured to be 5.30 A and 1.45% respectively,which are much better than the published results.In general,our work provides an efficient method to determine the design parameters of the wireless power transfer system for freely moving biomedical implants.

MATHEMATICAL MODELS OF MACROMOLECULAR CONFORMATIONS IN THE FORM OF RANDOM FLIGHT AND FREELY ROTATING POLYMER CHAINS

In this paper, two molecular mathematical models which simulate the conformations of a random flight chain and a freely rotating chain were suggested separately from the theory of stochastic process. We had obtained a series of results relating to conformations by means of these models. These results are not only mathematically stricter but also include the results obtained by previous workers. In an ideal state, conformation of a random flight chain is simulated as a 3-dimensional Brownian motion {r_t(ω), t>0}. We pointed out the objective meaning which was endowed to the different variables involved in a 3-dimensional Brownian motion. On this basis, the bond vector and the end-to-end state vector were defined; the distribution function and the reduced functions were thus obtained, e.g. the distribution of the end-to-end state vector which is a measure of the flexibility of a polymer chain,

Post-testing measurement of freely movable and diffusible hydrogen in context of WEC formation at cylindrical roller thrust bearings from 100Cr6

Sub-surface crack networks in areas of altered microstructure are a common cause for bearing failures.Due to its appearance under light microscopy,the damage pattern is referred to as White Etching Cracks(WEC).The root causes leading to the formation of WEC are still under debate.Nevertheless,it has already been shown that atomic hydrogen can have an accelerating effect on the formation and propagation of WEC.In addition to hydrogen pre-charging,hydrogen can be released and absorbed during rolling/sliding due to the decomposing of the lubricant and water.The current work focuses on the analysis of the hydrogen content of cylindrical roller thrust bearings after testing in a FE8 type test rig using two different lubricants.Within the framework of this work,two different hydrogen analysis methods were used and assessed regarding their applicability.The results show that the so-called Hydrogen Collecting Analysis(HCA)is more suitable to investigate the correlation between lubricant chemistry and hydrogen content in the test bearings than the Local Hydrogen Analysis(LHA).The measurements with the HCA show a continuously increasing freely movable and diffusible hydrogen content under tribological conditions,which leads to the formation of WEC.Comparative tests with an oil without hydrogen showed that the tendency of the system to fail as a result of WEC can be reduced by using a lubricant without hydride compounds.

To Fly Freely

BEFORE meeting Zhou Shuying, I only knew that she was a 32-year-old rural woman from Weixian County, Hebei Province who was good at paper-cutting. Afterwards, I realized that she was also a woman of lofty thoughts who knows something about freedom. Zhou Shuying was born in Zhouzhangzhuang Village, a specialized paper-cutting village in Weixian County.

Chas W.Freeman Speaks Freely

An interview with Chas W.Freeman,diplomat,author,and writer对话美国外交家、作家傅立民PIONEER PROFILE Chas W.Freeman Profession:Diplomat,author,and writer Nationality:AmericanThe 1970s were heady days for Sino-US diplomacy,with Nixon becoming the first American President to visit China.They were nervous days too,especially for American diplomat Chas W.Freeman who was

The Crop Journal Calls for Papers

We would like to invite you to submit your latest research accomplishments to The Crop Journal(ISSN:2095-5421;Online ISSN:2214-5141,CN 10-1112/S),a new bimonthly academic journal co-sponsored by the Crop Science Society of China and the Institute of Crop Science,Chinese Academy of Agricultural Sciences.The Crop Journal is freely available online(Open Access)in Science Direct.The Editor-in-Chief of The Crop Journal is Professor Jianmin Wan,Ph D,Cheung Kong Scholar,Director of the Institute of Crop Science and Executive Vice President of the Crop Science Society of China,supported

The Crop Journal Calls for Papers

We would like to invite you to submit your latest research accomplishments to The Crop Journal(ISSN:2095-5421;Online ISSN:2214-5141,CN 10-1112/S),a new bimonthly academic journal co-sponsored by the Crop Science Society of China and the Institute of Crop Science,Chinese Academy of Agricultural Sciences.The Crop Journal is freely available online(Open Access)in ScienceDirect.The

The Crop Journal Calls for Papers

We would like to invite you to submit your latest research accomplishments to The Crop Journal(ISSN:2095-5421;Online ISSN:2214-5141,CN 10-1112/S),a new bimonthly academic journal co-sponsored by the Crop Science Society of China and the Institute of Crop Science,Chinese Academy of Agricultural Sciences.The Crop Journal is freely available online(Open Access)in Science Direct.The Editor-in-Chief of The Crop Journal is Professor Jianmin Wan,Ph D,Cheung Kong Scholar,Director of the Institute of Crop Science and Executive Vice President of the Crop Science Society of China,supported

The Crop Journal Calls for Papers

We would like to invite you to submit your latest research accomplishments to The Crop Journal(ISSN:2095-5421;Online ISSN:2214-5141,CN 10-1112/S),a new bimonthly academic journal co-sponsored by the Crop Science Society of China and the Institute of Crop Science,Chinese Academy of Agricultural Sciences.The Crop Journal is freely available online(Open Access)in ScienceDirect.

The Crop Journal Calls for Papers

We would like to invite you to submit your latest research accomplishments to The Crop Journal(ISSN:2095-5421;Online ISSN:2214-5141,CN 10-1112/S),a new bimonthly academic journal co-sponsored by the Crop Science Society of China and the Institute of Crop Science,Chinese Academy of Agricultural Sciences.The Crop Journal is freely available online(Open Access)in ScienceDirect.The Editor-in-Chief

The Crop Journal Calls for Papers

We would like to invite you to submit your latest research accomplishments to The Crop Journal(ISSN:2095-5421;Online ISSN:2214-5141,CN 10-1112/S),a new bimonthly academic journal co-sponsored by the Crop Science Society of China and the Institute of Crop Science,Chinese Academy of Agricultural Sciences.The Crop Journal is freely available online(Open Access) in Science Direct.The Editor-in-Chief of The Crop Journal is Professor Jianmin Wan,PhD,Cheung Kong Scholar,Director of the Institute of Crop Science and Executive Vice President of the Crop Science Society of China,supported

The Crop Journal Calls for Papers

We would like to invite you to submit your latest research accomplishments to The Crop Journal(ISSN:2095-5421;Online ISSN:2214-5141,CN 10-1112/S),a new bimonthly academic journal co-sponsored by the Crop Science Society of China and the Institute of Crop Science,Chinese Academy of Agricultural Sciences.The Crop Journal is freely available online(Open Access)in ScienceDirect.The Editor-in-Chief of The Crop Journal is Professor Jianmin Wan,PhD,Cheung Kong Scholar,Director of the Institute of Crop Science and Executive Vice President of the Crop Science Society of China,supported by the Editorial Board of 85 international experts from various fields of crop sciences.

Introduction to Military Medical Research

Military Medical Research is an integral part of the BioMed Central journals.By publishing your work it becomes a fully citable open-access article-freely and universally accessible online,permanently archived,with copyright resting with the authors.MMR is indexed by PubMed,PMC and DOAJ.

The Crop Journal Calls for Papers

We would like to invite you to submit your latest research accomplishments to The Crop Journal(ISSN:2095-5421;Online ISSN:2214-5141,CN 10-1112/S),a new bimonthly academic journal co-sponsored by the Crop Science Society of China and the Institute of Crop Science,Chinese Academy of Agricultural Sciences.The Crop Journal is freely available online(Open Access)in ScienceDirect.