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Critical Role of Ethylene-Propylene Block Copolymer in Impact Polypropylene Copolymer

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Chinese Journal of Polymer science 2024年第3期42卷 344-351,I0007页

作者： Yu-Hui Tang Na Zhang Wei bao Wei Jiang Yuan lin Zhao-Hui Su State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Ethylene-propylene block copolymer(EbP) is a vital component in impact polypropylene copolymer(IPC), yet its distribution in the multiphase composite material and how it influences the phase structure and the mechanical properties are not well understood. In this work,four IPCs were investigated by atomic force microscopy-infrared(AFM-IR) to assess the phase compositions in situ, based on which in conjunction with the chain microstructure information obtained ex situ the distributions of the copolymer components were derived for each alloy. For the IPCs whose EbP comprises long P and long E segments, the EbP fraction was found to phase separate from the rubber and the PP matrix to form the cores of the disperse particles with the E-P segmented copolymer(EsP). In contrast, in the IPC with EbP composed of long P and short E segments, the EbP fraction formed an outer shell for the rubber particles with the cores comprising the EsP alone, and this IPC, containing a lower E comonomer content than its counterpart, exhibited both better impact resistance and higher flexural modulus. These results clarify how the chain structure of EbP governs the phase morphology in IPC, which in turn impacts the properties of the composite material.

关键词： Impact polypropylene copolymers AFM-IR Ethylene-propylene block copolymers Core-shell rubber particles

An improved approach to the efficient construction of and search operations in motion graphs

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science china(Information sciences) 2012年第5期55卷 1042-1051页

作者： GAO Yan 1,CHEN ZhiHua 2,CHEN MinGang 3 & SHEN Yang 3 1 Software Engineering institute,East china Normal university,shanghai 200062,china 2 Department of Computer science and Engineering,East china university of science and technology,shanghai 200237,china 3 Department of Computer science and Engineering,shanghai Jiao Tong university,shanghai 200240,china 1. Software Engineering institute East China Normal University Shanghai 200062 China2. Department of Computer Science and Engineering East China University of Science and Technology Shanghai 200237 China3. Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China

Motion graphs have been widely used as an effective technique in the synthesis of human *** synthesize well-formed motions,motion graphs require smooth transitions and good ***,the time and costs grow quadratically as the graph size *** this paper,we present a method to set up a hierarchical structure,called a structure *** coarse level of this graph models different motion categories and their transitions,and the fine level mainly captures different motion *** interpolation space method is used to improve the graph connectivity at the fine *** structure guides the establishment of a faster and more realistic graphical *** the building process,this structure also helps with searching the motion graph,by performing a traverse search and placing the findings into a direct look-up table or local search ***,when there is no direct link between the different motions,a navigation map is introduced to conduct an appropriate search path via a series of transition motion *** experimental results indicate that our approach could lower the computation time in construction and searching,while simultaneously providing a richer variety of motion styles.

关键词： motion graph structure table registration curve motion interpolation

A Novel Variational Formulation of Inverse Problem of Heat Conduction with Free Boundary on an Image Plane

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Journal of Thermal science 1996年第2期5卷 88-92页

作者： Gao-Lian liu(shanghai institute of Mechanical Engrg, shanghai 200093,china) shanghai institute of Mechanical Engrg Shanghai China

By introducing an image plane, the inverse heat conduction problem with free boundary is transformed into one with completely known boundaryt which is much simpler to *** a by-product, the classical Kirchhoff’s transformation for accounting for variable conductivity is rederived and an invariance property of the inverse problem solution with respect to variable conductivity is indicated. Then a pair of complementary extremum principles are established on the image plane, providing a sound theoretical foundation for the Ritz’s method and finite element method (FEM).An example solved by FEM is also given.

关键词： variational formulation inverse heat conduction problem

Multiple Positive Solutions of Nonlocal Boundary Value Problems for p-Laplacian Equations with Fractional Derivative

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Journal of Mathematical Research with Applications 2012年第3期32卷 327-336页

作者： Xiping liu,Mei JIA College of science,university of shanghai for science and technology,shanghai 200093,P.R.china College of science University of Shanghai for Science and Technology Shanghai 200093

In this paper,we study the multiple positive solutions of integral boundary value problems for a class of p-Laplacian differential equations involving the Caputo fractional *** a fixed point theorem due to Avery and Peterson,we obtain the existence of at least three positive decreasing solutions of the nonlocal boundary value problems. We give an example to illustrate our results.

关键词： p-Laplacian differential equations Caputo fractional derivative integral boundary value problems positive decreasing solutions Avery-Peterson fixed point theorem.

Boundary element-free method for elastodynamics

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science china(Physics,Mechanics & Astronomy) 2005年第6期48卷 641-657页

作者： CHENG Yumin1 & PENG Miaojuan2 1. shanghai institute of Applied Mathematics and Mechanics, shanghai university, shanghai 200072, china 2. Department of Civil Engineering, shanghai university, shanghai 200072, china 1. shanghai institute of Applied Mathematics and Mechanics Shanghai University 200072 Shanghai China 2. Department of Civil Engineering Shanghai University 200072 Shanghai China

The moving least-square approximation is discussed first. Sometimes the method can form an ill-conditioned equation system, and thus the solution cannot be obtained correctly. A Hilbert space is presented on which an orthogonal function system mixed a weight function is defined. Next the improved moving least-square approximation is discussed in detail. The improved method has higher computational efficiency and precision than the old method, and cannot form an ill-conditioned equation system. A boundary element-free method (BEFM) for elastodynamics problems is presented by combining the boundary integral equation method for elastodynamics and the improved moving least-square approximation. The boundary element-free method is a meshless method of boundary integral equation and is a direct numerical method compared with others, in which the basic unknowns are the real solutions of the nodal variables and the boundary conditions can be applied easily. The boundary element-free method has a higher computational efficiency and precision. In addition, the numerical procedure of the boundary element-free method for elastodynamics problems is presented in this paper. Finally, some numerical examples are given.

关键词： moving least-square approximation, improved moving least-square approximation, elastodynamics, boundary integral equation, meshless method, boundary element-free method, Fourier eigen transform.

Environmental Embrittlement in A_3B-type Intermetallic Alloys

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Journal of Materials science & technology 1994年第1期10卷 39-53页

作者： Xiaojing WAN Jiahong ZHU Kailiang JING Weijie CHEN and Yue WU(institute of Metallurgy and Materials science, shanghai university of technology, shanghai, 200072, china) shanghai Univ of technology Shanghai China

Environmental embrittlement in A3B-type intermetallics based on Ni3Al and Fe3Al has been studied in this paper. For the Ni3Al doped with 120 wt ppm B and Ni,(Al,***) doped with 80 wt ppm B,their elongation and ultimate tensile strength decreased in the sequence:of vacuum > air >hydrogen. while for Ni,(Al,Mn) doped with 400 wt ppm B no envifonmental degradation was ob served, although a -Ni3(Al,Mn) alloy without B showed a decrease in ductility when tested in air in stead of oxygen. It is supposed that boron and hydrogen compete for the occupation of interstitial sites near grain boundaries. If boron content is sufficiently low, hydrogen embrittlement occurs ;however, if its content is sufficiently high. boron addition is capable of eliminating envjronmental ef fect in Ni3Al-based alloysi As to the micromechanism of hydrogen embrittlement in Ni3Al+B. S EM in situ observations showed that both grain boundary decohesion and a high stress concentration con tributed to hydrogen-assisted jntergranu lar cracking in this alloy. For the Fe3Al and Fe3 (***) *** mechanical properties depended strongly on grain size / grain shape and testing environment. A strain rate effect on ductiIity and fracture strength was also observed in the Fe3Al and Fe,(Al,Cr)+B aIloys. Preoxidation increased the ductility of the Fe,(Al,Cr)+B alloy. All these results can be rationalized from a hypothesis that surface reaction is the controlling process in embrittling Fe3Al-based alloys.

关键词： Cr type Environmental Embrittlement in A3B-type Intermetallic Alloys Figure

SIMULATION OF THE OIL SLICK MOVEMENT IN TIDAL WATER-WAYS

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Journal of Hydrodynamics 2010年第1期22卷 96-102页

作者： WUZhao-chun WANG Dao-zeng shanghai institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China School of Construction and Safety Engineering Shanghai Institute of Technology Shanghai 200235 China

Based on particle approach and tidal flow model this article studies the behavior of the oil slick on the water surface in the Huangpu River, a tidal waterway in shanghai. In order to track the oil slick motion, a two-dimensional oil trajectory model is used. The dynamical properties of spilled oil characterized by advection, oil spreading and turbulent diffusion are considered in the model. The simulation results consistent with the flume experimental data show that the model is applicable. Both simulation and experiment illustrate that the tidal flow has a great influence on the oil slick motion. The calculated results can be used as a reference for the response to oil spill accidents in rivers.

关键词： particle approach track of oil slick numerical simulation

A simple solution route to control synthesis of Fe_3O_4 nanomaterials at low temperature and their magnetic properties

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science china Chemistry 2009年第7期52卷 916-923页

作者： liu Yi1,2, CHEN Yun1, ZENG YuPing2 & WANG ShiLong3 1 Department of Chemistry and Chemical Engineering, Zaozhuang university, Zaozhuang 277160, china 2 shanghai institute of Ceramics, Chinese Academy of sciences, shanghai 200050, china 3 School of Life science and technology, Tongji university, shanghai 200092, china 1. Department of Chemistry and Chemical Engineering Zaozhuang University Zaozhuang 277160 China 2. shanghai institute of Ceramics Chinese Academy of Sciences Shanghai 200050 China 3. School of Life science and technology Tongji University Shanghai 200092 China

A series of nanostructured iron compounds including cubic Fe3O4 and orthorhombic FeOOH were synthesized via a facile low temperature (in the range of 60-100℃) solution method. In the whole process, the interaction between FeCl2·4H2O and methenamine (C6H12N4) was carried out through a reflux device under different reaction conditions such as temperature, solvent, and duration. The samples were detected by XRD, TEM, SAED, physical property measurement system, and Mssbauer spectroscopy, separately. The experiments showed that magnetic mixture nanoparticles had flake and rod morphologies, and cubic Fe3O4 took on grain nanostructure. Magnetism measurements indicated that the saturated magnetization of the as-obtained magnetic mixture was lower than that of the cubic magnetite. Mssbauer spectroscopy testified the sample consisting of cubic magnetite rather than γ-Fe2O3. In addition, a possible growth mechanism of cubic magnetic nanoparticles under different conditions was discussed.

关键词： magnetic nanoparticles cubic Fe3O4 oxidation-coprecipitation method reflux magnetic properties at room temperature Mssbauer spectrum

NUMERICAL SOLUTION FOR TIDAL FLOW IN OPENING CHANNEL USING COMBINED MACCORMACK-FINITE ANALYSIS METHOD

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Journal of Hydrodynamics 2009年第4期21卷 505-511页

作者： WU Zhao-chun WANG Dao-zeng shanghai institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China School of Construction and Safety Engineering Shanghai Institute of Technology Shanghai 200235 China

A new numerical scheme for solving the tidal flow in an opening channel using the advective-diffusion shallow-water equations as the governing equations is proposed based on the combination of the MacCormack and the finite analysis methods. In the present scheme, the finite analysis method is used to discretize the momentum equation and the MacCormack technique is used to discretize the continuity equation in a single grid system. The matrix of the discretized momentum equation is characterized by predominantly main diagonal elements, which ensures favorable convergence and stability for the numerical simulation by the combined method. To verify the present method, hydraulics simulation is carried out for a section down mainstream of the Huangpu River. The computational results agree with the measured data. By use of orthogonal curvilinear coordinate system, the methods can be easily extended to the numerical simulation of the tidal flow in a tortuous channel.

关键词： MacCormack technique finite analysis method tidal flow shallow water equation numerical simulation