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A template-based knowledge reuse method for generating multitype 3D railway scenes

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International Journal of Digital Earth 2018年第2期11卷 179-194页

作者： Heng Zhang Jun Zhu Qing Zhu hua Qi Changjin Wang Zujie Han ya hu Xinwen Ning Faculty of Geosciences and Environmental Engineering Southwest Jiaotong UniversityChengduPeople’s Republic of China Engineering Laboratory The Third Railway Survey and Design Institute Group CorporationTianjinPeople’s Republic of China State-province Joint Engineering Laboratory of Spatial Information Technology for Highspeed Railway Safety Southwest Jiaotong UniversityChengduPeople’s Republic of China

Constructing 3D railway scenes helps improve the railway information construction ability and the comprehensive railway management ***,the existing modeling methods have disadvantages such as low flexibility in scene configuration,weak extensibility of scene objects and poor reusability of modeling *** enable multitype 3D railway scenes to be automatically constructed,a template-based knowledge reuse method was proposed in this ***,based on parsing of modeling operation characteristics and modeling knowledge expression,a modeling knowledge template was designed to store modeling knowledge and modeling operations in a parameterized *** contents of this template were described in terms of semantic information,geometric information,topologic information and reference system information,and the method for instantiating the modeling knowledge template was ***,a scene configuration template was designed to organize the instantiated modeling knowledge files and scene *** the use of a flexible tree structure,the scene configuration template enables extensibility of scene ***,the two types of templates were parsed in terms of scene organization,linear referencing information,geometric and topologic relationships,and semantic *** this way,different types of 3D railway scenes were generated *** a prototype system was developed,experiments on automatic modeling of two 3D railway scenes were carried out to verify the template-based knowledge reuse *** experimental results show that the proposed method can be used to generate multitype 3D railway scenes *** this method,model combination can be configured,model types can be extended and modeling knowledge can be reused.

关键词： Railway scene modeling knowledge template scene configuration template configurability of model combination extensibility and reusability

A molecular dynamics investigation of the deformation mechanism and shape memory effect of epoxy shape memory polymers

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Science China(Physics,Mechanics & Astronomy) 2016年第3期59卷 89-95页

作者： hua yang Zheng Dao Wang ya Fang Guo Xing hua Shi Institute of Engineering Mechanics Beijing Jiaotong University State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences

Following deformation, thermally induced shape memory polymers(SMPs) have the ability to recover their original shape with a change in temperature. In this work, the thermomechanical properties and shape memory behaviors of three types of epoxy SMPs with varying curing agent contents were investigated using a molecular dynamics(MD) method. The mechanical properties under uniaxial tension at different temperatures were obtained, and the simulation results compared reasonably with experimental data. In addition, in a thermomechanical cycle, ideal shape memory effects for the three types of SMPs were revealed through the shape frozen and shape recovery responses at low and high temperatures, respectively, indicating that the recovery time is strongly influenced by the ratio of E-51 to 4,4'-Methylenedianiline.

关键词： shape memory polymer molecular dynamics simulation thermomechanics

Synthesis of magnetically modified palygorskite composite for immobilization of Candida sp. 99–125 lipase via adsorption

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Chinese Journal of Chemical Engineering 2015年第5期23卷 822-826页

作者： ya Li Jicheng hu Pingfang Han College of Biotechnology and Pharmaceutical Engineering Nanjing Tech University Department of Environment and Resource Nantong Science and Technology College

Magnetically modified palygorskite composites were synthesized with γ-Fe2O3 dispersing on the external surface of clay mineral. The magnetic clay was characterized with Fourier transform infrared, X-ray diffrac- tion, transmission electron microscopy, and vibrating sample magnetometer. Candida sp. 99-125 lipase was immobilized on magnetic palygorskite composites by physical adsorption with enzyme loading of 41.5 mg· g^-1 support and enzyme activity of 2631.6 U· （g support）^-1. The immobilized lipase exhibit better thermal and broader pH stability and excellent reusabilitV compared with free lipase.

关键词： Magnetically modified palygorskite Immobilized lipase Adsorption Stability Reusability

Reconstruction of Core-Shell Dispersed Particles in Impact Polypropylene Copolymer during Extrusion

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Chinese Journal of Polymer Science 2015年第4期33卷 633-645页

作者： Feng Chen Bi-wei Qiu ya-nan Ye Yu-hua Lv 上官勇刚 Yi-hu Song 郑强 MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang University

We reported an approach to reconstruct the complex phase morphology of impact polypropylene copolymer （IPC） with core-shell dispersed particles and to optimize its toughness in approximate shear condition. The molten-state annealing results indicate that the phase structure with core-shell dispersed particles is unstable and could be completely destroyed by static annealing, resulting in the degradation of impact strength. By using a co-rotating twin screw extruder, we found that the dispersed particle with core-shell structure could be rebuilt in appropriate condition with the recovery of excellent impact strength due to both the huge interfacial tension during solidification and the great difference in viscosity of components. Results reveal that almost all the extruded IPCs show the impact strength 60%-90% higher than that of annealed IPCs at room temperature. And the twice-extruded IPC shows the highest impact strength, 446% higher than that of IPC annealed for 30 min. As for low temperature tests, the impact strength of extruded IPCs also increases by 33%-58%. According to adjusting the processing conditions including extrusion speed, extrusion frequency and temperature, an optimization of toughness was well established.

关键词： Impact polypropylene copolymer Shear Phase morphology Core-shell dispersed particle Impact strength.

Tensor Couplings of ω- and ρ-Mesons with Nucleons in a Derivative Scalar Coupling Model for Finite Nuclei

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Chinese Physics Letters 2001年第7期18卷 891-893页

作者： GUO hua hu Xiang Department of Technical Physics and MOE Laboratory of Heavy Ion Physics Peking UniversityBeijing 100871

Theω-andρ-meson tensor couplings to nucleons in a derivative scalar coupling model for finite nuclei are *** influences of the tensor couplings on the binding energies per nucleon,the root-mean-square charge radii,spin-orbit splittings and single particle energies are *** obtained results show that the spin-orbit splittings for finite nuclei are more sensitive to theω-meson tensor coupling.

关键词： tensor coupling meson

Effect of a viscoelastic target on the impact response of a flat-nosed projectile

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Acta Mechanica Sinica 2018年第1期34卷 162-174页

作者： hu Liu Jialing yang hua Liu Institute of Solid Mechanics Beihang University

Taylor impact is a widely used strategy in which a flat-nosed projectile is fired onto a rigid anvil directly to determine the dynamic strength of rod specimens. Nowadays, the rigid anvil is often replaced by an output target bar to ensure the accuracy of measurement via recording strain signals in the output bar. For testing the dynamic strength of low-density materials, a low-impedance target bar, which exhibits viscoelastic characteristics is often employed. In this paper, an extended Taylor model is proposed to improve the idealization of treating the target bar as perfectly rigid material in the classic Taylor model, and the viscoelastic effect of the target bar is incorporated. The viscoelastic target bar is depicted by two elastic springs and one dashpot. Based on the plastic shock wave theory in the flat-nosed projectile associated with the viscoelastic wave analysis in the target bar, the viscoelastic effect of the target bar on the impact response of the flat-nosed projectile is investigated. The finite element simulation is also carried out to verify the theoretical model,and good agreement is found. The present theoretical model is also called the Taylor-cylinder Hopkinson impact, which provides a more accurate way to identify the dynamic material parameters. The dynamic responses of the present model are further compared with previous elastic and rigid target bar models. It is found that the viscoelastic effect of the target bar should be taken into consideration in the Taylor-cylinder Hopkinson impact test for low-impedance materials.

关键词： Dynamic response Taylor impact Viscoelastic target Low-density material

Trustworthy Service Selection Integrating Cloud Model and Possibility Degree Ranking of Interval Numbers

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Chinese Journal of Electronics 2017年第6期26卷 1177-1183页

作者： MA hua hu Zhigang CAI Meiling School of Software Central South University Computer Education Department Hunan Normal University

It has been challenging to select suitable services from abundant candidates in cloud *** to the characteristics of batch computing mode and stream computing mode, a novel trustworthy service selection approach is proposed integrating cloud model and interval numbers theory. To facilitate potential users to understand the quality of service, the trustworthiness of service is described with interval number using reverse cloud generator, and the services with poor performance are filtered out by employing deviation degree or proximity degree. Two formulas of possibility degree of interval numbers are designed to compare the trustworthiness values between cloud services by utilizing probability zone analysis and geometrical analysis respectively, and the ranking method for possibility degree of interval numbers is exploited to select the most trustworthy service. The experiments show that this approach is effective to improve the accuracy of service selection and select trustworthy service for potential users in cloud paradigm.

关键词： Service selection Trustworthiness Cloud model Possibility degree ranking Interval numbers

RATE OF CONVERGENCE OF SCHWARZ ALTERNATING METHOD FOR TIME-DEPENDENT CONVECTION-DIFFUSION PROBLEM

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Journal of Computational Mathematics 2002年第5期20卷 479-490页

作者： Jian-wei hu Cai-hua Wang School of Mathematical Sciences Nankai University300071 Tianjin China Laboratory of Computational Physics IAPCM100088 Beijing China Department of Mathematics Tianjin Normal University300073 Tianjin China

Presents a study that examined the application of an overlapping domain decomposition method to the solution of time-dependent convection-diffusion problems. Background on the Schwartz alternating procedure; Applicati... 详细信息

关键词： rate of convergence Schwarz alternating method convection-diffusion problem

Fluctuation of Vegetative Storage Proteins in the Seedlings of Swietenia macrophylla, Analogous to the Seasonal Changes of Those in the Shoot of the Adult Tree

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Journal of Integrative Plant Biology 2007年第3期49卷 362-367页

作者： ya-Qin Han Xing-Fu yan hua Zhang Zheng-Hai hu Bing-Zhong Hao Wei-Min Tian Key Laboratory of Ministry of Agriculture for Tropical Crop Physiology Rubber Research Institute Chinese Academy of Tropical Agricultural Sciences Danzhou 571737 China College of Horticulture Shandong Agricultural University Tai'an 271018 China Institute of Botany the Chinese Academy of Sciences Beijing 100093 China Institute of Botany Northwest University Xi'an 710069 China

In order to Identify appropriate plant materials for studying the gene expression and biological function of vegetative storage proteins （VSPs） in woody plants, the VSPs in the seedlings of Swietenla rnacrophylla King were investigated by using light microscopy, sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE） and ***. The seed of S. macrophylla was rich in storage proteins that accumulated In the vacuoles of cotyledon parenchyma cells in appearance of compact spherical grains. The growth and development of S. macrophylla seedlings were characterized by an obvious growth rhythm. The storage proteins In seeds disappeared during seedling growth while VSPs appeared in the stem 2 weeks after seedling leaves matured. Thereafter, the VSPs In the seedling stem almost exhausted during new shoot growth, and when the leaves of new shoot Just matured, both the stem beneath the new shoot of seedlings and the stem of new shoot started to accumulate VSPs. Nitrogen application dramatically Increased the level of VSPs, but had little influence on the dynamics of VSP consumption and accumulation in seedling stem. Together with these data, the fluctuation of VSPs in seedlings was very similar to that in the branches of the adult trees. In addition, seedlings are easy to be treated due to their small size. Our results suggested that S. rnacrophylla seedlings were suitable for Investigating the biological roles of VSPs and the mechanism of nitrogen storage in trees.

关键词： rhythmical growth seedlings Swietenia macrophylla King vegetative storage proteins