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Flows Associated to Cameron-martin Type Vector Fields on Path Spaces Over a Riemannian Manifold

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Acta Mathematicae Applicatae Sinica 2013年第3期29卷 499-508页

作者： jing-xiao zhang Center for Applied Statistics School of StatisticsRenmin University of China

The flow on the Wiener space associated to a tangent process constructed by Cipriano and Cruzeiro, as well as by Gong and zhang does not allow to recover Driver’s Cameron-Martin theorem on Riemannian path space. The purpose of this work is to refine the method of the modified Picard iteration used in the previous work by Gong and zhang and to try to recapture and extend the result of Driver. In this paper, we establish the existence and uniqueness of a flow associated to a Cameron-Martin type vector field on the path space over a Riemannian manifold.

关键词： flow Cameron-Martin type vector field path space Riemannian manifold

Optimal Investment and Excess of Loss Reinsurance with Short-selling Constraint

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Acta Mathematicae Applicatae Sinica 2011年第3期27卷 527-534页

作者： Sheng Liu jing-xiao zhang Center for Applied Statistics School of Statistics Renmin University of China Beijing 100872 China

This paper considers the optimal control problem with constraints for an insurance company. The risk process is assumed to be a jump-diffusion process and the risk can be reduced through an excess of loss （XL） reinsurance. In addition, the surplus can be invested in the financial market. In the financial market, the short-selling constraint is one of the main factors which make models more realistic. Our goal is to find the optimal investment-reinsurance policy without short-selling, which maximizes the expected exponential utility of the terminal wealth. By solving the corresponding Hamilton-Jacobi-Bellman equation, the value function and the optimal investment-reinsurance policy are given in a closed form.

关键词： Hamilton-Jacobi-Bellman equation jump-diffusion process short-selling constraint XL reinsurance

An Integral Representation for the Weighted Geometric Mean and Its Applications

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Acta Mathematica Sinica,English Series 2014年第1期30卷 61-68页

作者： Feng QI xiao jing zhang Wen Hui LI School of Mathematics and Informatics He'nan Polytechnic University The 59th Middle School Luoyang Department of Mathematics School of ScienceTianjin Polytechnic University

By virtue of Cauchy’s integral formula in the theory of complex functions,the authors establish an integral representation for the weighted geometric mean,apply this newly established integral representation to show that the weighted geometric mean is a complete Bernstein function,and find a new proof of the well-known weighted arithmetic-geometric mean inequality.

关键词： Integral representation Cauchy's integral formula arithmetic mean geometric mean weighted arithmetic-geometric mean inequality complete Bernstein function new proof application

Numerical investigation on dynamic response of the screen mesh in vibrating screening through DEM-FEM co-simulation

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Particuology 2024年第4期87卷 205-217页

作者： Huan zhang xiao Zheng Weimin jing Key Laboratory of MetallurgicalEquipment and Control Technology Ministry of EducationWuhan University of Science and TechnologyWuhan430081 China Hubei Key Laboratory of Mechanical Transmssion and Manufacturing Engineering Wuhan University of Science and TechnologyWuhan430081China College of Mechanical and Vehicle Engineering Chongqing UniversityChongqing400044China

Dynamic response of the screen mesh is of great significance in the optimum vibrating screen *** this paper,based on the DEM-FEM co-simulation method,the effect of screening parameters on the dynamic response of the screen mesh is explored and the mechanism is revealed on the particle ***,a virtual experiment on a linear vibrating screen was carried out to analyze the screening pa-rameters'effect with both impact load and sustained stress inflicted on the screen ***,the time-domain evolution regularity of the screen mesh LVA(Local Vibration Amplitude)under different particle plugging conditions was investigated based on the ***,the influence of screening parameters on LVA and its distribution was *** results show that the screening parameters can greatly affect the screen mesh LVA and its distribution by changing the movement of the granular material and the particle penetration probability,which provides an important basis for the optimal design of the screen mesh and its supporting structure.

关键词： Vibrating screen Dynamic response DEM-FEM Screening parameters Local vibration amplitude

Electronic Effect of Carbon Support on Pt Catalyst Supported on Graphite Intercalation Compound

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Chemical Research in Chinese Universities 2010年第3期26卷 465-471页

作者： WEI Ang WANG Qing-jing ZHAO xiao-hui zhang Shu-yong Key Lab of Colloid and Interface Chemistry Ministry of Education School of Chemistry and Chemical Engineering Shandong University Jinan 250100 P. R. China

Graphite intercalation compounds（GIC） were tested as an experimental model for studying the electronic effect of carbon support on the catalytic activity and poisoning tolerance of Pt catalyst for direct methanol fuel cells. The GIC samples with different intercalation degrees were prepared by electrolyzing graphite flake in H2SO4 for varying the periods of time. The GIC-supported Pt catalyst was deposited electrochemically. The catalytic activity and poisoning tolerance of the GIC-supported Pt catalysts were evaluated. It was found that GIC with sulfate anion as intercalate was able to catalyze methanol electrooxidation, which could be related to the positive charges generated on the graphite layer upon intercalation. As intercalation degree increased, the catalytic activity of the GIC-supported Pt catalyst decreased while the poisoning tolerance improved. This suggests that electron donation from support to catalyst had great effect on both catalytic activity and poisoning tolerance of Pt catalyst. And intercalation can be adopted as another important way to make modification on carboneous catalyst support.

关键词： Catalyst support Electronic effect Graphite intercalation compound Catalytic activity Poisoning tolerance

H-bonding template-directed synthesis of a complete m-PDA-bridged ladder polyhydrosiloxane (OLPHS)

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Chinese Chemical Letters 2007年第7期18卷 779-782页

作者： Kui Lin Deng Tao Yi zhang xiao jing zhang Ping Xie Rong Ben zhang State Key Laboratory on Polymer Physics ＆ Chemistry Joint Laboratory of Polymer Science ＆ MaterialsInstitute of Chemistry Chinese Academy of Sciences Beijing 100080 China Graduate School of the Chinese Academy of Sciences Beijing 100039 China College of Chemistry ＆ Environmental Science Hebei University Baoding 071002 China

A highly ordered m-phenylenediimino-bridged ladder polyhydrosiloxane （abbr. OLPHS） with Mn = 1.24 × 10^4 was synthesized stoichiometric hydrolysis and dehydrochlorination condensation reaction between Si-Cl and Si-OH bonds. The complete ladder structure of OLPHS has been confirmed by the following three data. Two characteristic Bragg＇s peaks representing the ladder width （w = 0.94 nm） and ladder thickness （t = 0.42 nm） were observed in XRD analysis, which are consistent with those calculated by molecular simulation. The very sharp absorption with a small half-peak width （w1/2 = 0.5 ppm） for [（-HN）HSiO2/2]n moiety of OLPHS in ^29Si NMR spectrum indicated presence of the complete ladder structure. As collateral evidence, a higher glass transition temperature （Tg = 105 ℃） is also recorded in the DSC measurement, implying the high stiffness of ladder chain of OLPHS.

关键词： H-bonding template Ladder polysiloxane Self-assembly Stepwise coupling/polymerization

Synthesis and Biological Activity of Novel Spin Labeled Derivatives of 4′-Demethyl-4-deoxypodophyllotoxin

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Chemical Research in Chinese Universities 2010年第5期26卷 753-756页

作者： XU jing SUN xiao-hua zhang Jia-qiang zhang Zhi-wei TIAN Xuan State Key Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 730000 P. R. China

Seven novel spin labeled derivatives of 4＇-demethyl-4-deoxypodophyllotoxin with nitroxyl radi- cals（TMHPO and TMPRO） were prepared and their cytotoxic and antioxidative activities were tested. Their cytotoxic activities were tested against two tumor cell lines（A-549 and HL-60） in vitro. Among them, five compounds show higher inhibition activity against A-549 cells compared with the clinical drug VP-16（2） and parent compound 4＇-demethyl-4-deoxypodophyllotoxin（DDPT, 6）. Compounds 8, 10 and 13 show excellent inhibition activity against HL-60 cells. Furthermore, the antioxidative activities of them were tested. All the seven spin labeled compounds show stronger antioxidative activity compared with VP-16（2） and DDPT（6）. The partition coefficients P of these derivatives were determined.

关键词： 4'-Demethyl-4-deoxypodophyllotoxin Nitroxyl radical Antiturnor activity Antioxidative activity

An efficient parallel algorithm of variational nodal method for heterogeneous neutron transport problems

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Nuclear Science and Techniques 2024年第4期35卷 29-45页

作者： Han Yin xiao-jing Liu Teng-Fei zhang School of Nuclear Science and Engineering Shanghai Jiao Tong UniversityShanghai 2002040China

The heterogeneous variational nodal method(HVNM)has emerged as a potential approach for solving high-fidelity neutron transport ***,achieving accurate results with HVNM in large-scale problems using high-fidelity models has been challenging due to the prohibitive computational *** paper presents an efficient parallel algorithm tailored for HVNM based on the Message Passing Interface *** algorithm evenly distributes the response matrix sets among processors during the matrix formation process,thus enabling independent construction without *** the formation tasks are completed,a collective operation merges and shares the matrix sets among the *** the solution process,the problem domain is decomposed into subdomains assigned to specific processors,and the red-black Gauss-Seidel iteration is employed within each subdomain to solve the response matrix ***-to-point communication is conducted between adjacent subdomains to exchange data along the *** accuracy and efficiency of the parallel algorithm are verified using the KAIST and JRR-3 test *** results obtained with multiple processors agree well with those obtained from Monte Carlo *** parallelization of HVNM results in eigenvalue errors of 31 pcm/-90 pcm and fission rate RMS errors of 1.22%/0.66%,respectively,for the 3D KAIST problem and the 3D JRR-3 *** addition,the parallel algorithm significantly reduces computation time,with an efficiency of 68.51% using 36 processors in the KAIST problem and 77.14% using 144 processors in the JRR-3 problem.

关键词： Neutron transport Variational nodal method Parallelization KAIST JRR-3

A versatile strategy for convenient circular bivalent functional nucleic acids construction

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National Science Review 2023年第2期10卷 146-156页

作者： xiao-jing zhang Zhuo Zhao Xia Wang Min-Hui Su Lili Ai Yingying Li Quan Yuan Xue-Qiang Wang Weihong Tan Molecular Science and Biomedicine Laboratory (MBL) State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical Engineering College of Biology Aptamer Engineering Center of Hunan ProvinceHunan University Institute of Molecular Medicine (IMM) Renji HospitalShanghai Jiao Tong University School of Medicine and College of Chemistry and Chemical EngineeringShanghai Jiao Tong University The Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital) Hangzhou Institute of Medicine (HIM)Chinese Academy of Sciences

Functional nucleic acids(FNAs),such as aptamers,nucleic acid enzymes and riboswitches play essential roles in various fields of life *** of ingenious chemical moieties toward FNAs can enhance their biomedical properties and/or confer them with exogenic biological functions that,in turn,can considerably expand their biomedical applications,or even improve their clinical ***,we report the first example of a general chemical tailoring strategy that enables the divergent ligation of D NA *** applying this technology,different types of aptamers and single-stranded nucleic acids of various lengths could be efficiently tailored to deliver the designed circular bivalent aptamers(CBApts) and cyclized DNA se quences with high *** is worth noting that CBApts exhibited significantly enhanced nuclease resistance,as well as considerably improved binding,targeting and tumor tissue enrichment abilities,which may pave the way for different investigations for biomedical purposes.

关键词： circular bivalent aptamers click chemistry chemical ligation