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On the correction of the boundary deficiency in SPH for the frictional contact simulation

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Science China(Technological Sciences) 2014年第1期57卷 86-100页

作者： WANG jian HUA Hui gu ChongShi National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Hohai University College of Water Conservancy and Hydropower Engineering Hohai University

Smoothed particle hydrodynamics(SPH)is a mesh-free method which is powerful for large deformation computation of ***,the algorithm for the simulation of frictional contact which is common in geotechnical engineering is still quite immature due to the boundary *** this study,the cause of boundary deficiency in the SPH simulation for frictional contact is ***,based on mathematical derivation,the method to correct boundary deficiency related to frictional contact is discussed theoretically,where the frictional contact algorithm is established by dividing the computational domain into several subdomains according to the existing contact boundaries and by using contact forces as bridges of these subdomains to fulfil problem solving,and the value of correction coefficient is obtained by comparing the SPH outcome of the contact particles with that calculated through Newton’s second law of *** the same time,from the perspective of numerical computation,an optimized value for the correction coefficient is proposed,and a thorough investigation is performed on the cubic spline kernel function and quintic spline kernel function,whose correction coefficients are found to be 2.0 and[2.0,2.16],***,numerical tests are carried out to verify the proposed *** outcome of the study is helpful to providing theoretical support for the research of frictional contact simulation within the framework of SPH.

关键词： smoothed particle hydrodynamics (SPH) frictional contact boundary deficiency correction

A Note on Calculation of Phase Space Path Integral by Means of Invariants

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Communications in Theoretical Physics 2006年第5期45卷 813-814页

作者： QIAN Shang-Wu gu zhi-Yu physics Department Peking University Beijing 100871 China physics Department Capital Normal University Beijing 100037 China

In this note we use the method of invariant to calculate the phase space path integral appearing in our previous article.

关键词： phase space path integral invariant propagator

Polyethylenimine (PEI)g-comb-poly(ethylene glycol)-transferrin(I): Tumor-targeted Vector for Gene Delivery In-vitro

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Chinese Chemical Letters 2006年第1期17卷 113-116页

作者： gu Ping TANG zhi Yu WANG College of Life-Science. Zhejiang University Hangzhou 310028 Institute of Materials Research ＆ Engineering Singapore 3 Research Link 117602 The Second Hospital of Zhejiang University Hangzhou 310006

The work described the synthesis and evaluation of PEI-g-comb-PEG-transferrin as a potential system for gene therapy in vitro. The MW of PEG was 10KDa, and PEI was 2KDa. Its structure was identified by NMR, FT-IR and TGA spectroscopy. MTT assay found that at concentration up to 4000 n mol/L of the polymer, cell viability was over 85%. The bio-character of polymer/DNA complex was characterized by agarose gel electrophoresis, ethidium bromide exclusion and zeta-potential assay. The polymer could retardate DNA at N/P ratio 3.0-3.5 （mol/mol）. The particle size of the polymer/DNA complex was less than 300 nm. Transfection efficiency of the complex was studied in COS7 and NT2 cell lines.

关键词： PEI-g-Comb-PEG transferrin gene therapy transfection efficiency.

Knotted Picture of Unknown Quantum State in Process of Quantum Teleportation

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Communications in Theoretical Physics 2008年第5期49卷 1163-1164页

作者： gu zhi-Yu QIAN Shang-Wu Physics Department Capital Normal University Beijing 100037 China Physics Department Peking University Beijing 100871 China

This paper gives the knotted picture of the unknown quantum state in the process of quantum teleportation and the surgical knotted operations of the unitary operators operated on the teleported quantum state.

关键词： Bell bases single particle quantum state knotted picture flip operation inversion operation

Spatial patterns of the main trees in a plant micro-reserve constructed in the 2022 Beijing Winter Olympics mountainous competition zone

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Journal of Mountain Science 2023年第8期20卷 2228-2241页

作者： WANG jian-yong ZHANG zhi-xiang School of Ecology and Nature Conservation Beijing Forestry UniversityBeijing 100083China

Several plant micro-reserves were established to preserve the vegetation in local mountain areas during the construction of the Yanqing competition zone of the 2022 Beijing Winter *** spatial patterns of the main species in one of the micro-reserves and the factors affecting these patterns were characterized in this *** distribution of arbor species was found to be mostly aggregated,especially at fine scales(<5 m).Minor species were found to be more aggregated than the major species in each forest *** spatial patterns were found to be affected by habitat heterogeneity,intraspecific relationships,interspecific competition,and seed dispersal *** heterogeneity was found to affect large-scale spatial patterns,and its effects were observed throughout population *** competition is another factor affecting the distribution of the species,and its effects were stronger during the later stages of population *** heterogeneity was found to affect competition among species and is key for species *** these processes are affected by the seed dispersal limitation,and intraspecific relationships are a legacy of seed *** point patterns can be used as a tool for the initial assessment of the status of communities within *** consideration of these relationships in the development,management,and formulation of policies for micro-reserves in mountainous areas will facilitate the achievement of conservation *** careful consideration of habitat conditions when selecting sites for micro-reserves establishment can promote species conservation.

关键词： Spatial patterns Point patterns Microreserve Juglans mandshurica forest Beijing mountainous area

Ultrasound enhancement of the reduction of the Basic Green dye in wastewater by cast iron

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Journal of Environmental Sciences 2006年第1期18卷 1-3页

作者： SHEN Zhuang-zhi SHEN jian-zhong Institute of Acoustics Chinese Academy of Sciences Beijing 100080 China

Dyes in wastewater are of particular environmental concern since they give an undesirable color to the waters, dye and their derivatives are harmful to human health and the environment （ Annadurai et al., 2002）. Due to their biological persistency, conventional biological treat-ment processes such as activated sludge process are ineffective for their removal（Shaul et al., 1991）. There is a need to develop effective methods for the degradation of such persistent organic pollutants, either to less harmful compounds or, more desirable, to their complete mineralization.

关键词： cast iron ultrasound Basic Green combined effect

Sensitivity of Sample for Simulation-Based Reliability Analysis Methods

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Computer Modeling in Engineering & Sciences 2021年第1期126卷 331-357页

作者： Xiukai Yuan jian gu Shaolong Liu School of Aerospace and Engineering Xiamen UniversityXiamen361005China Institute for Risk and Reliability Leibniz Universitat HannoverHannoverGermany

In structural reliability analysis,simulation methods are widely *** statistical characteristics of failure probability estimate of these methods have been well *** this study,the sensitivities of the failure probability estimate and its statistical characteristics with regard to sample,called‘contribution indexes’,are proposed to measure the contribution of *** contribution indexes in four widely simulation methods,i.e.,Monte Carlo simulation(MCS),importance sampling(IS),line sampling(LS)and subset simulation(SS)are derived and *** proposed contribution indexes of sample can provide valuable information understanding the methods deeply,and enlighten potential improvement of *** is found that the main differences between these investigated methods lie in the contribution indexes of the safety samples,which are the main factors to the efficiency of the ***,numerical examples are used to validate these findings.

关键词： Reliability analysis Monte Carlo simulation importance sampling line sampling subset simulation

Knotted Picture of Unitary Transformation Applied to Single Particle Quantum State

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Communications in Theoretical Physics 2008年第1期49卷 65-68页

作者： gu zhi-Yu QIAN Shang-Wu Physics Department Capital Normal University Beijing 100037 China Physics Department Peking University Beijing 100871 China

This paper introduces the unified expression of four Bell bases and uses the composition operation in knot theory to obtain the knotted picture of unitary operators based on Pauli operators, and gives the knotted expr... 详细信息

关键词： Bell bases composition operation knotted picture inversion relation

Relationship Between Two Classes of Shape-Invariant Potentials

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Communications in Theoretical Physics 2001年第10期36卷 391-394页

作者： QIAN Shang-Wu gu zhi-Yu Department of Physics Peking University Beijing 100871 China Department of Physics Capital Normal University Beijing 100037 China

We show that two classes of shape-invariant potentials are interrelated to each other. For all one-dimensional shape-invariant potentials with parameters related by translation, i.e. the first class of shapc-invariant potentials (SIP1),we can find their multi-parameter deformations with q acting as the deformation parameter, i.e. the second class of shape-invariant potentials (SIP2) with parameters related by scaling. In order to get closed solution of SIP2, we consider two infinitesimal intervals, one is close to q= 0 another close to q = 1, and show that in these intervals we can get separately two first-order approximate solutions in closed form, furthermore we prove that all SIP1 can be obtained by the limiting procedures for corresponding SIP2.

关键词： shape-invariant potential, superpotential, multi-parameter deformation