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Real estate appraisal system based on GIS and BP neural network

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中国有色金属学会会刊：英文版 2011年第S3期21卷 626-630页

作者： LIU Xiao-sheng1, DENG Zhe1, WANG Ting-li2.1. school of Architecture and Survey Engineering, Jiangxi university of {2. and technology, Ganzhou 341000, china 2. school of Applied {2., Jiangxi university of {2. and technology, Ganzhou 341000, china [a] school of Architecture and Survey Engineering Jiangxi University of Science and Technology Ganzhou 341000 China [b] school of Applied science Jiangxi University of Science and Technology Ganzhou 341000 China

For the inefficiency and inaccuracy of appraisal method of traditional estate appraisal theory, the real estate appraisal system based on GIS and BP neural network was established. The structure of the system was designed which includes appraisal model, trade case, GIS database and query analysis module. With the help of the L-M algorithm in MATLAB software, BP neural network was improved and the trade cases were trained, then the BP neural network which has already been trained was tested. At the same time, the BP neural and GIS were put together to construct the hedonic price estimate model. The C# and ArcGIS9.3 were used to achieve the system in VS2.08. City basic geographic data and real estate related information were used as the basic data in practice. The results show that the functions of querying, adding and editing the spatial data and attribute data are achieved and also the efficiency and accuracy of real estate are improved, so that the new method of real estate is provided by the system.

关键词： BP neural network GIS hedonic price real estate appraisal

Syntheses of amphiphilic biodegradable copolymers of poly(ethyl ethylene phosphate) and poly(3-hydroxybutyrate) for drug delivery

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science china Chemistry 2009年第7期52卷 961-968页

作者： CHENG Jing1 & WANG Jun2.1 Department of Polymer science and Engineering, university of science and technology of china, Hefei 2.002., china 2.Hefei National Laboratory for physical sciences at Microscale, school of Life sciences, university of science and technology of china, Hefei 2.002., china Department of Polymer science and Engineering University of Science and Technology of China Hefei 230026 China Hefei National Laboratory for physical sciences at Microscale School of Life Sciences University of Science and Technology of China Hefei 230027 China

Biodegradable and amphiphilic triblock copolymers poly(ethyl ethylene phosphate)-poly(3-hydroxybutyrate)-poly(ethyl ethylene phosphate) (PEEP-b-PHB-b-PEEP) have been successfully synthesized through ring-opening polymerization. The structures are confirmed by gel permeation chromatography and NMR analyses. Crystallization investigated by X-ray diffraction reveals that the block copolymer with higher content of poly(ethyl ethylene phosphate) (PEEP) is more amorphous, showing decreased crystallizability. The obtained copolymers self-assemble into biodegradable nanoparticles with a coreshell micellar structure in aqueous solution, verified by the probe-based fluorescence measurements and transmission electronic microscopy (TEM) observation. The hydrophobic poly(3-hydroxybutyrate) (PHB) block serves as the core of the micelles and the micelles are stabilized by the hydrophilic PEEP block. The size and size distribution are related to the compositions of the copolymers. Paclitaxel (PTX) has been encapsulated into the micelles as a model drug and a sustained drug release from the micelles is observed. MTT assay also demonstrates that the block copolymers are biocompatible, rendering these copolymers attractive for drug delivery.

关键词： poly(3-hydroxybutyrate) polyphosphoester drug delivery polymeric nanoparticles

Dry electrode for the measurement of biopotential signals

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science china(Information sciences) 2011年第11期54卷 2435-2442页

作者： WANG Yu 1,2.PEI WeiHua 2.GUO Kai 2.GUI Qiang 2.LI XiaoQian 2.CHEN HongDa 2.& YANG JianHong 11 Institute of Microelectronics,school of physical {2. and technology,lanzhou university lanzhou 730000,china 2.State Key Laboratory on Integrated Optoelectronics,Institute of Semiconductors,Chinese Academy of {2.s,Beijing 100083,china 1. Institute of Microelectronics School of Physical Science and Technology Lanzhou University Lanzhou 730000 China2. State Key Laboratory on Integrated Optoelectronics Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China

This paper introduces a kind of silicon-based dry electrode for measuring biological *** uses microneedle arrays to penetrate into the stratum corneum to reduce skin *** dry electrode requires neither skin preparation nor the electrolytic gel,is easy to use and causes no skin *** different technologies are chosen to manufacture microneedle arrays of dry *** is deep dry etching combined with isotropic wet *** other is mechanical dicing combined with chemical wet etching (including isotropic wet etching and anisotropic wet etching).Microneedle arrays are coated with metal and divided into 2. mm 2.as dry electrode *** testing shows that the impedance value of dry electrode can be comparable with that of commercial electrode in the 2. Hz-10 kHz frequency *** steady-state visual evoked potential recording and analysis prove that the dry electrode can be used to detect electroencephalography.

关键词： dry electrode microneedle array dry etching wet etching EEG

Differences between laminar convections through parallel plain planes with uniform wall temperature and heat flux in terms of process parameter

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science china(Technological sciences) 2010年第3期53卷 789-799页

作者： WANG LiangBi,LIN ZhiMin,WU Xiang&SONG KeWei school of Mechatronic Engineering,lanzhou Jiaotong {2.,lanzhou 730070,china 1. school of Mechatronic Engineering Lanzhou Jiaotong University Lanzhou 730070 China

Using the process parameter description,we analyzed the difference between the characteristics of laminar convections through parallel plain planes with uniform temperature and heat *** results show the following.(1)On the wall surface of the developing region,under uniform heat flux boundary condition,the heat flux normal to the wall surface is transported through a convection process although the velocity is zero;the velocity gradient contributes to this transport,but under uniform temperature boundary condition,the heat flux normal to the wall surface is transported through a difussion process.(2.Inside the flow of the developing region,whether under uniform temperature or heat flux boundary condition,the heat flux along the main flow direction and the heat flux normal to the wall surface are transported through a convection process,and the contributions of velocity and velocity gradient are dependent on the thermal boundary condition.(3)On the wall surface of the fully developed region,under uniform heat flux boundary condition,the heat flux normal to the wall surface is transported through a convection process;the velocity gradient contributes to this transport,but under uniform temperature boundary condition,the heat flux normal to the wall surface is transported through a diffusion process.(4)Inside the flow of the fully developed region,under uniform temperature boundary condition,the heat flux along the main flow direction and the heat flux normal to the wall surface are transported through a convection process,and the velocity and velocity gradient contribute to these transports;under uniform heat flux boundary condition,the heat flux along the main flow direction and the heat flux normal to the wall surface are transported through a convection ***,the transport of the heat flux along the main flow direction is a no-net convection process;the velocity gradient contributes to the transport of the heat flux only in the normal direction o

关键词： mechanism of convective heat transfer description of process parameter parallel plain planes uniform wall temperature uniform wall heat flux laminar flow

Structure and kinematic analysis of a novel 2.DOF translational parallel robot

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Progress in Natural science:Materials International 2007年第10期17卷 1213-1219页

作者： Chen Tao1, Wu Chao2.and Liu Xinjun2.1. school of Application science and {2., Harbin university of science and {2., Harbin 150080, china 2. Department of Precision Instruments, Tsinghua university, Beijing 100084, china) school of Application science and {2. Harbin University of Science and Technology Harbin 150080 China Department of Precision Instruments Tsinghua University Beijing 100084 China

This paper addresses the analysis of a novel parallel robot with 2.translational degrees of freedom (DOFs). The robot can position a rigid body in a plane with constant orientation. The kinematic structure of the robot is first described in detail. Some kinematic problems, such as the inverse and forward kinematics, velocity, and singularity are then analyzed. The working and assembly modes are discussed. Since it is the most important index to design a robot, the workspace of the robot is studied systematically in this paper. Based on the analysis of reachable workspace and singularity, a kind of workspace concept characterizing the region that the end-effector of the robot can reach in practice is defined. The results of this paper will be very useful for the design and application of the robot.

关键词： parallel robot degree of freedom kinematics workspace.

SINGULAR BEHAVIORS OF INTERFACIAL CRACKS IN 2. MAGNETOELECTROELASTIC BIMATERIALS

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Acta Mechanica Solida Sinica 2009年第3期22卷 232-239页

作者： Cuiying Fan1 Youhe Zhou1 Han Wang2.Minghao Zhao1,2.1Key Laboratory of Mechanics on Disaster and Environment in Western china,the Ministry of Education of china,and Department of Mechanics and Engineering {2.,College of Civil Engineering and Mechanics,lanzhou university,lanzhou 730000,china)(2.8} of Mechanical Engineering,Zhengzhou university,Zhengzhou 450001,china) [a]Key Laboratory of Mechanics on Disaster and Environment in Western china the Ministry of Education of China and Department of Mechanics and Engineering Science College of Civil Engineering and Mechanics Lanzhou University Lanzhou 730000 China [b]School of Mechanical Engineering Zhengzhou University Zhengzhou 450001 China

The singular characteristics of stress,electric displacement and magnetic induction fields near the tip of impermeable interfacial cracks in two-dimensional magnetoelectroelastic bimaterials are studied using the generalized Stroh *** types of singularities are ob-tained:one is the oscillating singularity 1/2.iε,the other is the non-oscillating singularity 1/2.κ.It is found that the non-zero parameters ε and κ cannot coexist for one transversely isotropic MEE bimaterial,a similar result is obtained for transversely isotropic piezoelectric bimaterials.

关键词： generalized Stroh formalism magnetoelectroelastic bimaterial interfacial crack singularity index

Some interesting CH_2.H_3 spin systems in several diethyl malonate indene derivatives studied with NMR and molecular modeling

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science china Chemistry 2009年第7期52卷 937-942页

作者： ZHANG Long1, HE WeiWei1, LIANG YongMin2.& CUI YuXin1 1 State Key Laboratory of Natural and Biomimetic Drugs, school of Pharmaceutical sciences, Peking {2., Beijing 100191, china 2.State Key Laboratory of Applied Organic Chemistry, lanzhou university, lanzhou 730000, china State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical Sciences Peking University Beijing 100191 China State Key Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 730000 China

While studying the electrophilic cyclization of acetylenic malonates in synthesizing malonate indene derivatives with high regio and stereo-selectivity, we found that the CH2.and CH3 protons of two COOCH2.H3 groups in some diethyl malonate indene derivatives showed very interesting spin-spin coupling and signal multiplicity. To explain those phenomena, we synthesized several diethyl malonate indene derivatives, and then used 1H NMR spectra and molecular modeling to investigate the CH2.H3 spin system of these two COOCH2.H3 groups in detail. The results showed that the spin systems of CH3CH2.of the two COOCH2.H3 groups in those compounds may exist in different froms (AMX3, ABX3 and A2.3), and the effect of the aromatic ring induced by the phenyl group at the end of the triple bond is the main reason responsible for those phenomena.

关键词： electrophilic cyclization spin-spin coupling signal multiplicity molecular modeling spin system aromatic ring

Guided wave propagation in multilayered piezoelectric structures

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science china(Physics,Mechanics & Astronomy) 2009年第7期52卷 1094-1104页

作者： GUO YongQiang1, CHEN WeiQiu2.3 & ZHANG YongLiang4 1 Key Laboratory of Mechanics on Disaster and Environment in Western china, Ministry of Education, and school of Civil Engineering and Mechanics,{2., lanzhou 730000, china 2.Key Laboratory of Soft Soils and Geoenvironmental Engineering, Ministry of Education, and Department of Civil Engineering, Zhejiang university, Hangzhou 310058, china 3 Department of Engineering Mechanics, Zhejiang university, Hangzhou 31002., china 4 school of Civil Engineering, lanzhou Jiaotong university, lanzhou 730070, china Key Laboratory of Mechanics on Disaster and Environment in Western china Ministry of Education and School of Civil Engineering and Mechanics Lanzhou University Lanzhou 730000 China Key Laboratory of Soft Soils and Geoenvironmental Engineering Ministry of Education and Department of Civil Engineering Zhejiang University Hangzhou 310058 China Department of Engineering Mechanics Zhejiang University Hangzhou 310027 China school of Civil Engineering Lanzhou Jiaotong University Lanzhou 730070 China

A general formulation of the method of the reverberation-ray matrix (MRRM) based on the state space formalism and plane wave expansion technique is presented for the analysis of guided waves in multilayered piezoelectric structures. Each layer of the structure is made of an arbitrarily anisotropic piezoelectric material. Since the state equation of each layer is derived from the three-dimensional theory of linear piezoelectricity, all wave modes are included in the formulation. Within the framework of the MRRM, the phase relation is properly established by excluding exponentially growing functions, while the scattering relation is also appropriately set up by avoiding matrix inversion operation. Consequently, the present MRRM is unconditionally numerically stable and free from computational limitations to the total number of layers, the thickness of individual layers, and the frequency range. Numerical examples are given to illustrate the good performance of the proposed formulation for the analysis of the dispersion characteristic of waves in layered piezoelectric structures.

关键词： multilayered piezoelectric structures the method of reverberation-ray matrix guided waves dispersion characteristic

Cu_2.nSnS_4 thin films prepared by sulfurizing different multilayer metal precursors

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science china(Technological sciences) 2009年第1期52卷 269-272页

作者： ZHANG Jun & SHAO LeXi school of physical {2. and technology, Zhanjiang Normal university, Zhanjiang 52.048, china school of physical {2. and technology Zhanjiang Normal University Zhanjiang 524048 China

Cu2.nSnS4 (CZTS) thin films were successfully fabricated on glass substrates by sulfurizing Cu-Sn-Zn multilayer precursors, which were deposited by ion beam sputtering and RF magnetron sputtering, respectively. The structural, electrical and optical properties of the prepared films under various processing conditions were investigated in detail. Results showed that the as-deposited CZTS thin films with the precursors by both ion beam sputtering and RF magnetron sputtering have a composition near stoichiometric. The crystallization of the samples, however, has a strong dependence on the atomic percent of constituents of the prepared CZTS films. A single phase stannite-type structure CZTS with a large absorption coefficient of 104/cm in the visible range could be obtained after sulfurization at 52.℃ for 2.h. The samples relative to the RF magnetron sputtering showed a low resistivity of 0.073 ?cm and band gap energy of about 1.53 eV. The samples relative to the ion beam sputtering exhibited a resistivity of 0.36 Ωcm and the band gap energy is about 1.51 eV.

关键词： Cu_2.nSnS_4 solar cell thin film ion beams sputtering RF sputtering