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Electromagnetic field effects on nucleon transverse momentum for heavy ion collisions around 100 A MeV

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Nuclear Science and Techniques 2017年第12期28卷 255-261页

作者： Xian-Gai Deng Yu-Gang ma Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China ShanghaiTech University Shanghai 200031China

With taking electromagnetic field into account for the transport model of Boltzmann-Uehling-Uhlenbeck,electromagnetic effects are studied for ^(208)Pb +^(208)Pb collisions around 100A MeV. Electromagnetic field evolution during the collisions was estimated. It was found that the electric field has an obvious effect on the transverse momentum(p_T) spectra of nucleons during heavy ion collisions, and leads to different minimum position for the peak of p_T spectra of nucleons versus beam energy when the electric field is switched on. For the magnetic field, it affects the z-axis direction distributions of nucleons for central heavy ion collisions at lower energy.

关键词： Heavy ion collision Electromagnetic field Transverse momentum

Numerical simulation of martian historical dynamo:Impact of the Rayleigh number on the dynamo state

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Science China Earth Sciences 2009年第3期52卷 402-410页

作者： WANG TianYuan KUANG Weijia ma ShiZhuang Laboratory for Computational Geodynamics Graduate University of Chinese Academy of SciencesBeijing 100049China Planetary Geodynamics Laboratory NASA Goddard Space Flight CenterGreenbeltMD 20771USA

The observed mars remnant magnetism suggests that there was an active dynamo in the martian core. We use the MoSST core dynamics model to simulate the martian historical dynamo, focusing on the variation of the dynamo states with the Rayleigh number Ra (a non-dimensional parameter describing the buoyancy force in the core). Our numerical results show that the mean field length scale does not vary monotonically with the Rayleigh number, and the field morphology at the core mantle boundary changes with Rayleigh number. In particular, it drifts westward with a speed decreasing with Rayleigh number.

关键词： mars magnetic field Rayleigh number dynamo

An ultra-fast and highly efficient multiple proteases digestion strategy using graphene-oxide-based immobilized protease reagents

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Science China Chemistry 2014年第5期57卷 695-702页

作者： BAI HaiHong PAN YiTing REN XiaoJun HAO FeiRan DENG ShanShan FAN Chao YAN Hui SHEN BingQuan ma lin TIAN Fang PENG Bo DENG Yulin QIN WeiJie QIAN XiaoHong School of Life Science and Technology Beijing Institute of Technology National Center for Protein Sciences Beijing State Key Laboratory of Proteomics Beijing Proteome Research CenterBeijing Institute of Radiation Medicine

Highly efficient and rapid proteolytic digestion of proteins into peptides is a crucial step in shotgun-based proteome-analysis strategy. Tandem digestion by two or more proteases is demonstrated to be helpful for increasing digestion efficiency and de- creasing missed cleavages, which results in more peptides that are compatible with mass-spectrometry analysis. Compared to conventional solution digestion, immobilized protease digestion has the obvious advantages of short digestion time, no self-proteolysis, and reusability. We proposed a multiple-immobilized proteases-digestion strategy that combines the ad- vantages of the two digestion strategies mentioned above. Graphene-oxide （GO）-based immobilized trypsin and endoprotein- ase Glu-C were prepared by covalently attaching them onto the GO surface. The prepared GO-trypsin and GO-Glu-C were successfully applied in standard protein digestion and multiple immobilized proteases digestion of total proteins of Thermoan- aerobacter tengcongensis. Compared to 12-hour solution digestion using trypsin or Glu-C, 14% and 7% improvement were obtained, respectively, in the sequence coverage of BSA by one-minute digestion using GO-trypsin and GO-GIu-C. Multiple immobilized-proteases digestion of the total proteins of Thermoanaerobacter tengcongensis showed 24.3% and 48.7% en- hancement in the numbers of identified proteins than was obtained using GO-trypsin or GO-Glu-C alone. The ultra-fast and highly efficient digestion can be contributed to the high loading capacity of protease on GO, which leads to fewer missed cleavages and more complete digestion. As a result, improved protein identification and sequence coverage can be expected.

关键词： graphene oxide Trypsin GIu-C immobilized protease multiple proteases digestion

Comparison on Soil Carbon Stocks Between Urban and Suburban Topsoil in Beijing, China

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Chinese Geographical Science 2014年第5期24卷 551-561页

作者： LUO Shanghua maO Qizheng ma Keming State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Science Chinese Academy of Sciences Center for Human-Environment System Sustainability Beijing Normal University

The urban population and urbanized land in China have both increased markedly since the 1980 s. Urban and suburban developments have grown at unprecedented rates with unknown consequences for ecosystem functions. In particular, the effect of rapid urbanization on the storage of soil carbon has not been studied extensively. In this study, we compared the soil carbon stocks of different land use types in Beijing Municipality. We collected 490 top-soil samples(top 20 cm) from urban and suburban sites within the Sixth Ring Road of Beijing, which cover approximately 2400 km2, and the densities of soil organic carbon(SOC), soil inorganic carbon(SIC), and total carbon(TC) were analyzed to determine the spatial distribution of urban and suburban soil carbon characteristics across seven land use types. The results revealed significant differences in soil carbon densities among land use types. Additionally, urban soil had significantly higher SOC and SIC densities than suburban soil did, and suburban shelterbelts and productive plantations had lower SIC densities than the other land use types. The comparison of coefficients of variance(CVs) showed that carbon content of urban topsoil had a lower variability than that of suburban topsoil. Further findings revealed that soil carbon storage increased with built-up age. Urban soil built up for more than 20 years had higher densities of SOC, SIC and TC than both urban soil with less than 10 years and suburban soil. Correlation analyses indicated the existence of a significantly negative correlation between the SOC, SIC, and TC densities of urban soil and the distance to the urban core, and the distance variable alone explained 23.3% of the variation of SIC density and 13.8% of the variation of TC density. These results indicate that SOC and SIC accumulate in the urban topsoil under green space as a result of the conversion of agricultural land to urban land due to the urbanization in Beijing.

关键词： urban soil soil organic carbon (SOC) soil inorganic carbon (SIC) carbon stock land use change built-up age Beijing China

A General Description Schema of Services for WSNs

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Chinese Journal of Electronics 2014年第3期23卷 604-610页

作者： SUN Yan ma Xiaoqiong LUO Hong Beijing Key Lab of Intelligent Telecommunication Software and Multimedia Beijing University of Posts and Telecommunication

With the rapid development of Wireless sensor networks(WSNs) in recent years, users have been more interested in the services that WSNs can provide rather than data itself. To better bridge between data in different WSNs provided by different developers and comprehensive services required by users, a general service description language used in WSNs is needed. In this paper, we propose a general description schema of services— General service description language(GSDL), which is an XML-like language and can describe simple or composite services. This language makes use of tags agreement,compression and binary coding mechanisms so as to greatly reduce the size of service description document. Moreover,we design a lightweight service composition and decomposition algorithm, which can be executed at each service broker. Compared with widely used WSDL, GSDL is more compact, flexible and suitable for service description in WSNs.

关键词： Wireless sensor network General services description language Service composition Service decomposition

Synthesis, crystal structure and properties of a new organic-inorganic hybrid Dawson-like polyoxotungstate [Co(2,2′-bpy)_3]_2[Co(2,2′-bpy)_2Cl][Co(2,2′-bpy)_2]H_2- [SbW_(18)O_(60)]·4H_2O

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Science China Chemistry 2007年第6期50卷 784-789页

作者： WANG JingPing ma PengTao NIU JingYang Institute of Molecular and Crystal Engineering School of Chemistry and Chemical Engineering Henan University Kaifeng 475001 China Institute of Molecular and Crystal Engineering School of Chemistry and Chemical Engineering Henan University Kaifeng 475001 China Institute of Molecular and Crystal Engineering School of Chemistry and Chemical Engineering Henan University Kaifeng 475001 China

A new organic-inorganic hybrid polyoxometalate based on Dawson-like polyoxotungstate anion [SbW18O60]9, formulated [Co(2,2′-bpy)3]2[Co(2,2′-bpy)2Cl][Co(2,2′-bpy)2]H2[SbW18O60]·4H2O (2,2′-bpy= 2,2′-bipyridine) has been synthesized from Sb2O3, Na2WO4, CoCl2, and 2,2′-bipyridine materials by hydrothermal method, and which was characterized by elemental analyses, IR, XPS, EPR, TG, and X-ray single crystal diffraction. Structure analysis shows that the polyoxoanion self-assembled under hydrothermal conditions consists of a Dawson-like polyoxotungstate cluster anion [SbW18O60]9 en- capsulating a pyramidal {SbO3} group within the {W18} cluster cage. EPR spectra show that the high-spin octahedral CoII and low-spin CoII ions coexist in the title compound. magnetic properties in- dicate that the compound is antiferromagnetic.

关键词： polyoxometalate, Dawson-like, crystal structure, hydrothermal synthesis

Microblog User Recommendation Based on Particle Swarm Optimization

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China Communications 2017年第5期14卷 134-144页

作者： ling Xing Qiang ma ling jiang School of Information Engineering Henan University of Science and Technology School of Information Engineering Southwest University of Science and Technology School of mathematics Science and Computer Wuyi UniversityWuyishan

Considering that there exists a strong similarity between behaviors of users and intelligence of swarm of agents,in this paper we propose a novel user recommendation strategy based on particle swarm optimization(PSO)for Microblog network. Specifically,a PSO-based algorithm is developed to learn the user influence,where not only the number of followers is incorporated,but also the interactions among users(e.g.,forwarding and commenting on other users' tweets). Three social factors,the influence and the activity of the target user,together with the coherence between users,are fused to improve the performance of proposed recommendation strategy. Experimental results show that,compared to the well-known Page Rank-based algorithm,the proposed strategy performs much better in terms of precision and recall and it can effectively avoid a biased result caused by celebrity effect and zombie fans effect.

关键词： particle swarm optimization Microblog social network user recommendation user influence

Infrared and Visible Image Fusion Based on Res2Net-Transformer Automatic Encoding and Decoding

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Computers, materials & Continua 2024年第4期79卷 1441-1461页

作者： Chunming Wu Wukai Liu Xin ma Key Laboratory of Modern Power System Simulation and Control&Renewable Energy Technology School of Electrical EngineeringNortheast Electric Power UniversityJilin132012China School of Electrical Engineering Northeast Electric Power UniversityJilin132012China School of Aeronautical Engineering Jilin Institute of Chemical TechnologyJilin132022China

A novel image fusion network framework with an autonomous encoder and decoder is suggested to increase thevisual impression of fused images by improving the quality of infrared and visible light picture fusion. The networkcomprises an encoder module, fusion layer, decoder module, and edge improvementmodule. The encoder moduleutilizes an enhanced Inception module for shallow feature extraction, then combines Res2Net and Transformerto achieve deep-level co-extraction of local and global features from the original picture. An edge enhancementmodule (EEM) is created to extract significant edge features. A modal maximum difference fusion strategy isintroduced to enhance the adaptive representation of information in various regions of the source image, therebyenhancing the contrast of the fused image. The encoder and the EEM module extract features, which are thencombined in the fusion layer to create a fused picture using the decoder. Three datasets were chosen to test thealgorithmproposed in this paper. The results of the experiments demonstrate that the network effectively preservesbackground and detail information in both infrared and visible images, yielding superior outcomes in subjectiveand objective evaluations.

关键词： Image fusion Res2Net-Transformer infrared image visible image

Impacts of the Diurnal Cycle of Solar Radiation on Spiral Rainbands

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Advances in Atmospheric Sciences 2016年第9期33卷 1085-1095页

作者： Shunwu ZHOU Yue ma Xuyang GE Key Laboratory of Meteorological Disaster of Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044 Shanghai Climate Center Shanghai 200030

Based on idealized numerical simulations, the impacts of the diurnal cycle of solar radiation on the diurnal variation of outer rainbands in a tropical cyclone are examined. It is found that cold pools associated with precipitation-driven downdrafts are essential for the growth and propagation of spiral rainbands. The downdrafts result in surface outflows, which act as a lifting mechanism to trigger the convection cell along the leading edge of the cold pools. The diurnal cycle of solar radiation may modulate the diurnal behavior of the spiral rainbands. In the daytime, shortwave radiation will suppress the outer convection and thus weaken the cold pools. Meanwhile, the limited cold pool activity leads to a strong modification of the moisture field, which in turn inhibits further convection development.

关键词： solar shortwave radiation tropical cyclone spiral ralnbands diurnal cycle