检索结果-南通市图书馆

Ab Initio Calculations of the Electronic Structures of Copper Pyrites CuS2, CuSe2 and CuTe2

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2004年第4期20卷 429-431页

作者： Zhufeng HOU, Aiyu LI, Zizhong ZHU and Meichun HUANGDepartment of phys.cs, Xiamen University, Fujian 361005, China dept. of phys. Xiamen Univ. Xiamen 361005 China

The electronic structures of CuS2, CuSe2 and CuTe2 with pyrite structures, within the framework the density-functional theory have been investigated. The calculated results explained the recent experimental results which show that there is no clear indication of strong electron correlations in the electronic properties of Cu pyrites, due to the dominant chalcogen p character rather than d characteristic of Cu at the Fermi level.

关键词： Ab initio calculations Copper pyrites Electronic structures

Determination of Effective Segregation Coefficient of Oxygen in Terbium During Floating Zone Refining

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2001年第2期19卷 140-141页

作者：李国栋刘永林 dept. of phys. Inner Mongolia Univ. Hohhot 010021 China

The effective segregation coefficient K-e of oxygen in terbium metal was deduced from a comparison of the theoretical curves with the concentration distributions found experimentally after a floating zone refining treatment. Thp result shows that K-e is equal to 1.2 which is an important parameter for floating zone refining terbium.

关键词： rare earths terbium floating zone refining effective segregation coefficient of oxygen

Effects of Substrate Temperature on Properties for Transparent Conducting ZnO:A1 Films on Organic Substrate Deposited by r.f. Sputtering

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2001年第5期17卷 517-520页

作者： Deheng ZHANG, Dejun ZHANG and Qingpu WANG Department of phys.cs, Shandong University, Jinan 250100, China Tianlin YANG Institute of Zibo, Zibo 255091, China dept. of phys. Shandong Univ. Ji'nan 250100 China

This paper presents the substrate temperature dependence of opto-electrical properties for transparent conducting Al-doped ZnO films prepared on polyisocyanate (PI) substrates by r f sputtering. Polycrystalline ZnO:Al films with good adherence to the substrates having a (002) preferred orientation have been obtained with resistivities in the range from 4.1×10-3to 5.3×104 Ωcm, carrier densities more than 2.6×1020 cm-3 and Hall mobilities between 5.78 and 13.11 cm2/V/s for films. The average transmittance reaches 75% in the visible spectrum. The quality of obtained films depends on substrate temperature during film fabrication.

关键词： ZnO Sputtering Effects of Substrate Temperature on Properties for Transparent Conducting ZnO Al

Timing umbilical therapy in treatment of neurogenic bladder after spinal cord injury based on midnight-noon and ebb-flow doctrine:a randomized controlled trial

在线全文

学校读者我要写书评

暂无评论

China med.cal Abstracts(Internal med.cine) 2024年第1期41卷 7-7页

作者：王东利 dept Orthopedics Traumatol&RehabCangzhou Integr Chin&West Med HospCangzhou 061000

Objective To observe the clinical efficacy of timing umbilical therapy for neurogenic bladder after spinal cord injury based on the midnight-noon and ebb-flow *** Sixty patients with neurogenic bladder after spinal co... 详细信息

关键词： bladder neurogenic clinical

An eSnake model for med.cal image segmentation

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2005年第5期15卷 424-429页

作者： Lv Hongyu1, YUAN Kehong2, BAO Shanglian1, ZU Donglin1 and DUAN Chaijie1*(1. The Research Center for Tumor Diagnosis and Therapeutical phys.cs & Beijing Key Laboratory of med.cal phys.cs and Engineering, Beijing 100871, China 2. Key Laboratory of Pure and Applied Mathematics, School of Mathematical Sciences, Peking University, Beijing 100871, China) Beijing Key Lab. of med. phys. and Eng. Res. Ctr. for Tumor Diagnosis and Therapeutical Phys. Beijing 100871 China Key Lab. of Pure and Applied Math. Sch. of Math. Sci. Peking Univ. Beijing 100871 China

A novel scheme of external force for detecting the object boundary of med.cal image based on Snakes (active contours) is introduced in the paper. In our new method, an electrostatic field on a template plane above the original image plane is designed to form the map of the external force. Compared with the method of Gradient Vector Flow (GVF), our approach has clear phys.cal meanings. It has stronger ability to conform to boundary concavities, is simple to implement, and reliable for shape segmenting. Additionally, our method has larger capture range for the external force and is useful for med.cal image preprocessing in various applications. Finally, by adding the balloon force to the electrostatic field model, our Snake is able to represent long tube-like shapes or shapes with significant protrusions or bifurcations, and it has the specialty to prevent Snake leaking from large gaps on image edge by using a two-stage segmentation technique introduced in this paper. The test of our models proves that our methods are robust, precise in med.cal image segmentation.

关键词： image segmentation eSnake external force electrostatic field balloon force.

MULTIPLE-SCATTERING DETERMINATION TO THE LOCAL ADSORPTION GEOMETRY OF SO_2/Pd(111)

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2002年第1期15卷 81-86页

作者： S. Cao J.C. Tang P. Zhu L. Wang S.L Shen dept. of phys. Zhejiang Univ. Hangzhou 310027 China

We have calculated the sulphur 1s near edge X-ray absorption fine structure (NEXAFS) spectra of SO2 adsorbed on Pd (111) in terms of the Multiple-Scattering Cluster (MSC) method. The origin of the resonances in the NEXAFS spectra has been revealed. By the MSC calculation and a (DV)-Xα study we have for the first time identified two weak features existing in S K-edge NEXAFS of SO2/Pd(111) system, which are attributed to the interaction between the adsorbate and the substrate. Moreover, MSC calculation together with the reliability factor (R-factor) analysis are employed to determine the local adsorption structures. These results are broadly in agreement with those of Fourier-transform analysis of the surface extended X-ray absorption fine structure (SEXAFS).

关键词： Absorption Geometry Palladium Scattering Sulfur dioxide X ray spectroscopy

EFFECT OF PHOTOOXIDATION ON PHOTOLUMINESCENCE OF N, N'-DIPHENYL-N, N'-DI(M-TOLYL)-BENZIDINE AND RUBRENE CODOPED PMMA THIN FILMS

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2001年第6期14卷 441-447页

作者： YB. Hou, L.J. Meng and M.P. dos Santos ( Department of phys.cs, Minho University, Braga 4719, Portugal) ( Departamento de Fisica, Instituto Superior de Engenharia do Porto, Rua de Sao Tome, 4200 Porto, Portugal) dept. of phys. Minho Univ. Braga 4719 Portugal

In this paper, the PMMA films doped with N,N'-diphenyl-N,N'-di(m-tolyl)-benzidine and rubrene were fabricated by spin coating, and the effect of photooxidation on the photoluminescence of the doped PMMA thin films was investigated. The results showed that under the irradiation of 350nm UV light, N,N'-diphenyl-N,N'-di(m-tolyl)-benzidine can sensitized rubrene and results in the enhancement in the photooxidation of rubrene. The effect of photooxidation on the photoluminescence from rubrene was more obvious. Both lifetime measurement and in situ measurement of photoluminescence showed that rubrene molecules exist in two chemical surroundings.

关键词： photoluminescence photooxidation

Phase Matching of SHG in Arbitrary Directions of Biaxial Crystals

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Lasers 2002年第1期11卷 24-27页

作者： YANG Shengli CHEN Mouzhi (phys. dept. of Xiamen Univ., Xiamen 361005, China) phys. dept. of Xiamen Univ. Xiamen 361005

In this paper, propagation and polarization characteristics of optical waves in arbitrary directions in a biaxial crystal are analyzed, and universal relationships of refractive index dependence on their propagation directions and the principal refractive indices for two perpendicular polarization waves propagating in arbitrarily directions are derived from indicatrix equation. By using these relationships, methods of collinear phase matching (PM) of SHG are developed, and general expressions of the collinear PM angle dependent of the principal indices are given for SHG in arbitrarily directions. The expressions may be used to make optimization design of PM by computer for the SHG and to select optimum PM direction and to raise the SHG conversion efficiencies.

关键词： biaxial crystal second harmonic generation (SHG) collinear PM PM angle

CHAOTIC MOTION PRODUCED IN FREE CONVECTIVE AND INERTIAL MOTION OF ATMOSPHERE

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 1993年第3期13卷 273-281页

作者：朱凯成李湘如 dept. of phys. Jishou Univ. Jishou 410000 China dept. of phys. Jiangxi Normal Univ. Nanchang 330034 China

In this paper a nonlinear model of convective and inertial motion of atmosphere with damping is studied with Melnikov's function method. The results show that in the atmospheric motion under periodic forcing chaos can occur independently whether the atmospheric motion is stable or not; and it is the key to produce chaos that the distribution of relevant phys.cal quantity is nonlinear and periodically drives exists. The formulae calculating the parameter ranger in which chaos occur are given as well.

关键词： In ab CHAOTIC MOTION PRODUCED IN FREE CONVECTIVE AND INERTIAL MOTION OF ATMOSPHERE