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Non-isothermal study of gasification process of coal char and biomass char in CO_2 condition

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Journal of Iron and Steel Research International 2017年第10期24卷 985-990页

作者： Tao xu Guang-wei Wang Jian-liang Zhang Teng-fei Song Run-sheng xu School of Metallurgical and Ecological Engineering University of Science and Technology Beijing School of Materials and Metallurgy Wuhan University of Science and Technology

Non-isothermal method was used to study gasification characteristics of three coal chars and one biomass *** chars were made from anthracite coal（A）,bituminous coal（B）,lignite coal（L）,and wood refuse（W）,*** gasification process was studied by random pore model（RPM）,unreacted core model（URCM）and volumetric model（VM）.With an increase in metamorphic grade,the gasification reactivity of coal char decreased,and the gasification reactivity of biomass char was close to that of low metamorphic coal *** an increase in heating rate,the gasification of all samples moved towards high temperature zone,and the whole gasification time *** was concluded from kinetics analysis that the above-mentioned three models could be used to describe the gasification process of coal char,and the RPM fitted the best among the three *** the RPM,the activation energies of gasification were193.9,225.3 and 202.8 kJ/mol for anthracite coal char,bituminous coal char and lignite coal char,*** gasification process of biomass char could be described by the URCM and VM,while the URCM performed *** activation energy of gasification of wood refuse char calculated by the URCM was 282.0 kJ/mol.

关键词： Coal char Biomass char Gasification Kinetic model

Palladium-Catalyzed Cross-Coupling of Fluorinated Vinyl Chlorides with Terminal Alkynes： A General Protocol to Fluorinated Enynes

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Chinese Journal of Chemistry 2013年第7期31卷 901-907页

作者： sheng Chen Chunfa xu Long Lu Qilong Shen Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032 China

An efficient and cost-effective method for the preparation of fluorinated conjugated enynes was described, tile method was compatible with a variety of functional groups such as chloride, amine, cyano and ester group. The method could also be extended to the coupling of （R,Z）-3-（2-chloro-1,2-difluorovinyl）-4-alkyloxazolidin-2-one （3） with moderate yields.

关键词： fluorine enyne palladium chlorotrifluoroethylene

Enhancing Unsupervised Domain Adaptation for Person Re-Identification with the Minimal Transfer Cost Framework

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Computers, Materials & Continua 2024年第9期80卷 4197-4218页

作者： sheng xu Shixiong Xiang Feiyu Meng Qiang Wu Research Institute of Electronic Science and Technology University of Electronic Science and Technology of ChinaChengdu610000China National Key Laboratory of Optical FieldManipulation Science and Technology Chinese Academy of SciencesChengdu610209China

In Unsupervised Domain Adaptation(UDA)for person re-identification(re-ID),the primary challenge is reducing the distribution discrepancy between the source and target *** can be achieved by implicitly or explicitly constructing an appropriate intermediate domain to enhance recognition capability on the target *** construction is difficult due to the absence of intermediate state supervision,making smooth knowledge transfer from the source to the target domain a *** explicitly construct the most suitable intermediate domain for the model to gradually adapt to the feature distribution changes from the source to the target domain,we propose the Minimal Transfer Cost Framework(MTCF).MTCF considers all scenarios of the intermediate domain during the transfer process,ensuring smoother and more efficient domain *** framework mainly includes threemodules:Intermediate Domain Generator(IDG),Cross-domain Feature Constraint Module(CFCM),and Residual Channel Space Module(RCSM).First,the IDG Module is introduced to generate all possible intermediate domains,ensuring a smooth transition of knowledge fromthe source to the target *** reduce the cross-domain feature distribution discrepancy,we propose the CFCM Module,which quantifies the difficulty of knowledge transfer and ensures the diversity of intermediate domain features and their semantic relevance,achieving alignment between the source and target domains by incorporating mutual information and maximum mean *** also design the RCSM,which utilizes attention mechanism to enhance the model’s focus on personnel features in low-resolution images,improving the accuracy and efficiency of person *** proposed method outperforms existing technologies in all common UDA re-ID tasks and improves the Mean Average Precision(mAP)by 2.3%in the Market to Duke task compared to the state-of-the-art(SOTA)methods.

关键词： Person re-identification unsupervised domain adaptation attention mechanism mutual information maximum mean discrepancy

Asymptotic Property of Approximation to x~αsgn x by Newman Type Operators

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Acta Mathematicae Applicatae Sinica 2010年第4期26卷 617-624页

作者： Qian Zhan Shu-sheng xu Yue-hong Zhang Department of Mathematics Anhui University of Sciences and Technology Huainan 232001 China East China University of Sciences and Technology Shanghai 200237 China Yuanpei college Shaoxing University Shaoxing 312000 China

Approximation to the function ｜x｜ plays an important role in approximation theory. This paper studies the approximation to the function xαsgn x, which equals ｜x｜ if α = 1. We construct a Newman Type Operator rn... 详细信息

关键词： Rational approximation asymptotic property Newman type operator

Non-Gaussian feature of the output field from a double qubit-cavity ultrastrong coupling system

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Communications in Theoretical Physics 2024年第7期76卷 30-36页

作者： sheng-wen xu Shi-yu Dai Teng Zhao Center for Quantum Science and Technology Jiangxi Normal UniversityNanchang 330022China

We investigate the non-Gaussian feature of radiation in a circuit quantum electrodynamics(QED)system where two qubits are strongly coupled to a single-mode *** the regime of ultrastrong coupling(USC),the rotating-wave approximation is not valid,and the Rabi Hamiltonian contains counter-rotating wave terms,leading to level crossing and avoided crossings in the energy *** further analyze the intensity-amplitude correlation of the output field in these two novel *** the USC regime,the creation and annihilation operators in the correlation function are replaced,allowing for the identification of non-Gaussian features in the output *** findings reveal that despite the absence of squeezing effects in the output light,significant non-Gaussian characteristics are ***,we demonstrate that as the driving or coupling strength increases,the non-Gaussian features of the output field become more *** suggests that USC systems hold broad potential applications in the realms of nonlinear optics and the generation of non-Gaussian states.

关键词： ultrastrong coupling non-Gaussian intensity-amplitude correlation

Deposition of Ti-Si-N coatings in deep blind-hole with pulsed dc power

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中国有色金属学会会刊：英文版 2004年第z1期14卷 260-263页

作者： MA Da-yan MA sheng-li xu Ke-wei State Key Laboratory for Mechanical Behavior of Materials Xi''an Jiaotong University Xi''an 710049 China State Key Laboratory for Mechanical Behavior of MaterialsXi''an Jiaotong University Xi''an 710049 China State Key Laboratory for Mechanical Behavior of MaterialsXi''an Jiaotong University Xi''an 710049 China

Multiphase nanocomposite Ti-Si-N coatings deposited by pulsed dc plasma enhanced chemical vapor deposition technique on the surface of HSS substrate, which were bolted with deep blind-hole to simulate the complexshaped surface of various tools, were investigated. The micrographs show that the surface morphologies of the coatings become coarser with an increasing depth of the bottom holes. And the silicon content increases in Ti-Si-N coatings, which are composed of nanocrystalline TiN, nano-sized amorphous Si3N4, and occasionally amorphous or nanocrysralline TiSi2. The thickness of the coatings decreases with the increasing depth of holes, which may result from the changes of the composition in the coatings. The microhardness of the coatings increases firstly with the increasing depth of holes, reaches a maximum value of about HV5 700 at 10mm depth, and then decreases at larger depth.

关键词： nanocomposite pulsed dc PCVD Ti-Si-N deep blind-hole

Influence of Sedimentation on Crystallization of Charged Colloidal Particles

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Chinese Journal of Chemical Physics 2012年第3期25卷 318-324,374页

作者： xuan Du sheng-hua xu Zhi-wei Sun Lei Liu Key Laboratory of Microgravity Institute oF Mechanics Chinese Academy of Sciences Beijing 100190China National Microgravity Laboratory Institute of Mechanics Chinese Academy of Sciences Beiijing100190 China

The method of density matching between the solid and liquid phases is often adopted to effectively eliminate the effect of sedimentation of suspensions on dynamic behavior of a colloidal system. Experiments on crystallization of charged colloidal microspheres with di- ameter of 98 nm dispersed in density-matched and -unmatched media （mixtures of H20 and D20 in proper proportion） are compared to examine the influence of sedimentation. Reflection spectra of colloidal suspensions were used to monitor the crystallization process. Results showed that the crystal size of the density-unmatched （namely, in the presence of sedimentation） sample grew faster than that of the density-matched （in the absence of sedi- mentation） case at the initial stage of the crystallization, and then the latter overtook and outstripped the former. To explain these observations, we assume that in the settling of crystals sedimentation facilitates result in more particles getting into the crystal structures. However, as the crystals increase to varying sizes, the settling velocities become large and hydrodynamic friction strips off some particles from the delicate crystal structures. Overall, the sedimentation appears to accelerate the crystal size growth initially and then retard the growth. In addition, the crystal structures formed under microgravity were more closely packed than that in normal gravity.

关键词： Colloidal crystal Density matching Sedimentation Reflection spectrum

Atomistic simulations of the surface severe plastic deformation-induced grain refinement in polycrystalline magnesium:The effect of processing parameters

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Journal of Magnesium and Alloys 2022年第5期10卷 1242-1255页

作者： Xiaoye Zhou Hui Fu Ji-Hua Zhu xu-sheng Yang Guangdong Province Key Laboratory of Durability for Marine Civil Engineering School of Civil EngineeringShenzhen UniversityShenzhenGuangdong 518060China State Key Laboratory of Ultra-precision Machining Technology Advanced Manufacturing Technology Research CentreDepartment of Industrial and Systems EngineeringThe Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Hong Kong Polytechnic University Shenzhen Research Institute ShenzhenChina

Magnesium(Mg)based alloys are promising candidates for many applications,but their untreated surfaces usually have low strength and *** this study,a single point diamond turning(SPDT)technique was applied to refine the grain size and improve the mechanical properties of the surface layers of Mg-Li *** refining grains in the topmost layer to the nanometer scale(~60 nm),the surface hardness was found to be enhanced by approximately 60%.The atomic plastic deformation process during the SPDT was then studied by the real-time atomistic molecular dynamics(MD)simulations.A series of MD simulations with different combinations of parameters,including rake angle,cutting speed and cutting depth,were conducted to understand their influences on the microstructural evolution and associated plastic deformation mechanisms on the surface layer of the *** MD simulation results suggest that using increased rake angle,cutting speed and cutting depth can help to achieve better grain *** simulation results,which provide atomic-level details of the deformation mechanism,can assist the parameter design for the SPDT techniques to achieve the high-performance heterogeneous nanostructured materials.

关键词： Mg alloy Grain refinement Surface severe plastic deformation MD simulations

Effects of Climate Warming on Phenological Characteristics of Urban Forest in Shenyang City,China

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Chinese Geographical Science 2016年第1期26卷 1-9页

作者： HE Xingyuan xu sheng xu Wenduo CHEN Wei HUANG Yanqing WEN Hua State Key Laboratory of Forest and Soil Ecology Institute of Applied EcologyChinese Academy of Sciences Northeast Institute of Geography and Agroecology Chinese Academy of Sciences

Change in plant phenology is one of the most sensitive ecological responses to climate warming. Little information is known about the effects of climate warming on phenology of urban tree species in the northern forest of China. In this study, we investigated the phenological characteristics of the main tree species in the urban forest of shengyang City in China and the correlation between phenology and atmospheric temperature from the discontinuous data during past 42 years over three time periods(from 1962 to 1965, 1977 to 1978, and 2000 to 2005). The results showed that the annual average temperature in Shenyang City showed an increasing trend and increased by 0.96℃ from 1962 to 2005 due to climate warming. The germination phenology of the urban trees was negatively correlated with the temperature in winter and early spring. The leafing phenology was mainly influenced by the temperature in spring before leafing. Influenced by climate warming, the germination, leafing, and flowering phenologies of this urban forest in 2005 were 14, 13, and 10 days earlier than those in 1962, respectively. We inferred that further warming in winter might prolong the growing season of urban trees in the northern forest of China.

关键词： global climate change global warming plant phenology urban forest shengyang City