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Primordial Black Holes and Cosmic String Loop

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Chinese Physics Letters 1996年第4期13卷 317-320页

作者： cheng Hong-bo LI Xin-zhou East China Institute for Theoretical Physics Shanghai 200237 School of Science East China University of Science and TechnologyShanghai 200237 Department of Physics Shanghai Teacher's UniversityShanghai 200234

The elliptic loop equation of cosniic string is studied in the Minkowski space and during the radiation-dominated era in the Robertson-Walker universe.A remarkable fact about this equation is that a loop may never con... 详细信息

关键词： equation radius circular

Time-varying diffusion characteristics of different gases in coal particles

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International Journal of Mining Science and Technology 2017年第6期27卷 1025-1029页

作者： Long Qingming Hu Qianting cheng bo College of Resources and Environmental Science Chongqing University Chongqing 400030 China National Key Laboratory of Gas Disaster Detecting Preventing and Emergency Controlling Chongqing 400037 China Chongqing Research Institute China Coal Research Institute Chongqing 400037 China

Based on the analytical solution of gas diffusion in spherical coal particles with a constant diffusion coefficient, a calculation method of time-varying diffusion coefficient is proposed by constructing objective function. The time-varying diffusion behavior of methane, nitrogen and carbon dioxide in the coal particles was studied. The results show that with the increase of diffusion time, the diffusion coefficients of methane, nitrogen and carbon dioxide gas in the coal particles exhibit an attenuation characteristic, eventually approaching a limit value individually. The diffusion coefficient of carbon dioxide is larger than methane, and the diffusion coefficient of nitrogen is smallest. Significant phenomenon of limited diffusion was observed for coal of strong adsorption capability. Through the analysis of the diffusion coefficient of gases at different diffusion time, a mathematical model describing the time-varying diffusion characteristic of gases is obtained. The implementation of mixed gases to replace coal bed methane has a very important practical significance.

关键词： Coal Coalbed methane (CBM) Adsorption Diffusion Objective function

Patterned glass ceramic design for high-brightness high-color-quality laser-driven lightings

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Journal of Advanced Ceramics 2022年第6期11卷 862-873页

作者： Qiugui HUANG Hang LIN bo WANG Shisheng LIN Pengfei WANG Ping SUI Ju xu Yao cheng Yuansheng WANG Key Laboratory of Optoelectronic Materials Chemistry and Physics Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China College of Chemistry and Materials Science Fujian Normal UniversityFuzhou 350007China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China School of Applied Physics and Materials Wuyi UniversityJiangmen 529020China

Up-to-date laser-driven lightings confront a challenge of simultaneously achieving good photometric and chromatic ***,the coupling of“patterned package design”and“phosphor wheel”was proposed and demonstrated effectively to deal with this tough issue,based on a new architecture of CaAlSiN3:Eu2+(CASN:Eu)glass ceramic film(GCF)on Y_(3)Al_(5)O_(12):Ce^(3+)(YAG:Ce)GC *** fabricated composite has no interface between the two functional layers and retains the admirable luminescent features from CASN:Eu and YAG:Ce for the microstructural integrity during *** studies on laser-microcrystalline interactions reveal that the luminescence saturation is almost determined by thermal quenching for YAG:Ce,but is ascribed to thermal/intensity quenching which are equally crucial for CASN:*** from the elaborate architecture design,good color chromaticity tunability was obtained,and severe photon reabsorption was ***,accompanied with the rotation induced increase of thermal convection to air and pulse-like excitation,the constructed lighting engine under blue laser driven shows bright white light with luminous flux(LF)higher than 1000 lm,adjustable chromaticity from cool to warm,and improved color rendering index(CRI)approaching to 70.

关键词： laser lightings glass ceramics(GCs) white light garnets nitrides

Two New Steroidal Glycosides from Liriope muscari

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Chinese Chemical Letters 2006年第1期17卷 31-34页

作者： Zhi Hong cheng Tao WU Yin Long GUO bo Yang YU Luo Shan xu School of Chinese Pharmacy China Pharmaceutical University Nanjing 210038 Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032 Institute of Chinese Materia Mcdica Shanghai University of Traditional Chinese Medicine Shanghai 201203

Two new steroidal glycosides named Lm-4 （1） and Lm-5 （2） were isolated from the tubers of Liriope muscari. Their structures were elucidated by 1D and 2D NMR, ESI/MALDIMS techniques, and chemical methods.

关键词： Liriope muscari steroidal glycoside Lm-4 Lm-5.

Low-complexity fractional phase estimation for totally blind channel estimation

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Journal of Systems Engineering and Electronics 2015年第2期26卷 232-240页

作者： xu Wang Tao Yang bo Hu Department of Electronic Engineering Fudan University Key Laboratory of EMW Information Fudan University

To remove the scalar ambiguity in conventional blind channel estimation algorithms, totally blind channel estimation （TBCE） is proposed by using multiple constellations. To estimate the unknown scalar, its phase is decomposed into a fractional phase and an integer phase. However, the maximum-likelihood （ML） algorithm for the fractional phase does not have closed-form solutions and suffers from high computational complexity. By ex- ploring the structures of widely used constellations, this paper proposes a low-complexity fractional phase estimation algorithm which requires no exhaustive search. Analytical expressions of the asymptotic mean squared error （MSE） are also derived. The theo- retical analysis and simulation results indicate that the proposed fractional phase estimation algorithm exhibits almost the same performance as the ML algorithm but with significantly reduced computational burden.

关键词： orthogonal frequency division multiplexing(OFDM) totally blind channel estimation(TBCE) scalar ambiguity fractional phase low-co

Development and characterization of a clinical strain of Coxsackievirus A16 and an eGFP infectious clone

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Virologica Sinica 2015年第4期30卷 269-276页

作者： chenglin Deng Xiaodan Li Siqing Liu Linlin xu Hanqing Ye cheng-Feng Qin bo Zhang Key Laboratory of Special Pathogens and Biosafety Wuhan Institute of Virology Chinese Academy of Sciences University of Chinese Academy of Sciences State Key Laboratory of Pathogen and Biosecurity Beijing Institute of Microbiology and Epidemiology

Coxsackievirus A16(CA16) is one of the major causes of hand, foot, and mouth disease(HFMD) worldwide, which is a common illness that affects children. The frequent occurrence of HFMD outbreaks has become a serious public health problem in Asia. Therefore, it is important to understand the pathogenesis and replication of CA16. In this study, a stable infectious c DNA clone of an epidemic strain of Coxsackievirus A16(CA16) was assembled, and subsequently a reporter virus(e GFP-CA16) was constructed by inserting the e GFP gene between the 5'-UTR and the N-terminus of VP4, with the addition of a 2A protease cleavage site(ITTLG) at its C-terminus. This was transfected into Vero cells to generate infectious recombinant viruses. The growth characteristics and plaque morphology, in vitro, in mammalian cells were found to be indistinguishable between the parental and recombinant viruses. Although the e GFP-CA16 showed smaller plaque size as compared to recombinant CA16, both were found to exhibit similar growth trends and EC50 of NITD008. In summary, this stable infectious c DNA clone should provide a valuable experimental system to study CA16 infection and host response. The e GFP-CA16 is expected to provide a powerful tool to monitor e GFP expression in infected cells and to evaluate the antiviral activity of potential antiviral agents in the treatment of CA16 infections.

关键词： Coxsackievirus A16(CA16) infectious cDNA clone rep

Research on momentum transfer in simple railgun

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Defence Technology（防务技术） 2019年第5期15卷 735-740页

作者： Yingtao xu bo Tang Baoming Li The National Key Laboratory of Transient Physics Nanjing University of Science and Technology

In this paper,the momentum conservation equation in the longitudinal direction for simple railgun was ***,a three-dimensional model was established and the finite element method was utilized to simulate the *** on the simulation,some results such as the surface force on the electromagnetic field,the electromagnetic force on the conductor in the longitudinal direction were ***,the surface force density on different longitudinal section of railgun was analyzed and discussed in *** results showed that the momentum of the railgun system was conserved when the surface force of the electromagnetic field was ***,large amount of longitudinal force was transmitted to the breech by the electromagnetic field in the form of surface *** exact position and distribution of recoil were related to the current input device.

关键词： Railgun Momentum conservation Recoil Surface force

Improving multi-layer spiking neural networks by incorporating brain-inspired rules

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Science China(Information Sciences) 2017年第5期60卷 226-236页

作者： Yi ZENG Tielin ZHANG bo xu Institute of Automation Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology Chinese Academy of Sciences

This paper introduces seven brain-inspired rules that are deeply rooted in the understanding of the brain to improve multi-layer spiking neural networks(SNNs). The dynamics of neurons, synapses, and plasticity models are considered to be major characteristics of information processing in brain neural ***, incorporating these models and rules to traditional SNNs is expected to improve their efficiency. The proposed SNN model can mainly be divided into three parts: the spike generation layer, the hidden layers, and the output layer. In the spike generation layer, non-temporary signals such as static images are converted into spikes by both local and global feature-converting methods. In the hidden layers, the rules of dynamic neurons,synapses, the proportion of different kinds of neurons, and various spike timing dependent plasticity(STDP)models are incorporated. In the output layer, the function of classification for excitatory neurons and winner take all(WTA) for inhibitory neurons are realized. MNIST dataset is used to validate the classification accuracy of the proposed neural network model. Experimental results show that higher accuracy will be achieved when more brain-inspired rules(with careful selection) are integrated into the learning procedure.

关键词： brain-inspired rules spiking neural network plasticity classification task

Strengthening synergistic effects between hard carbon and soft carbon enabled by connecting precursors at molecular level towards high-performance potassium ion batteries

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Nano Research 2023年第8期16卷 10985-10991页

作者： Hongqiang xu boshi cheng Quan Du Yuting Zhang Haojie Duan Ishioma L.Egun bo Yin Haiyong He Ningbo Institute of Materials Technology and Engineering Chinese Academy of SciencesNingbo 315201China University of Chinese Academy of Sciences Beijing 101400China

Synergistic effects between hard carbons and soft carbons are proven to be helpful for improving the electrochemical performance of carbonaceous anode for potassium-ion batteries(PIBs).However,the phase separation of precursors limits the synergistic effects and improvement of electrochemical ***,inspired by the esterification reaction,the precursors of two sorts of carbon are connected at the molecular level,which boosts the synergistic effects in hybrid carbon,resulting in excellent electrochemical kinetics and low charge/discharge ***,the hybrid carbon anode exhibited a high specific capacity of 121 mAh·g^(−1)at 3.2 A·g^(−1),a high-rate capability,and stable cycling *** 500 cycles at 1 A·g^(−1),the average capacity fading is only 0.078%per cycle.

关键词： potassium ion batteries anode carbon chemical bond