检索结果-南通市图书馆

Acta Metallurgica Sinica(English Letters) 2001年第6期14卷 497-500页

作者： J. Xu, X.H. Huang, L. Wang, W. Li and K.J. Chen (National Laboratory of Solid State Microstructures and Departmeat of physics, Nanjing University, Nanjing 210093, China) J.B. Xu (Department of Electronic Engineering, The Chinese University of Hong Kong, S dept. of phys. Nanjing Univ. Nanjing 210093 China

Hydrogenated amorphous carbon films were fabricated by using layer-by-layer deposition method and hydrogen dilution method in a small d.c.-assisted plasma enhanced chemical vapor deposition system. It was found that the hydrogen plasma treatment could change the sp2/sp3 ratio to some extent by chemical etching. The improvements of field emission characteristics were observed compared with that from conventionally deposited a-C films, which can be attributed to the large field enhancement effect due to the inhomogeneous distribution of nanometer scale sp2 clusters and the reduction of the surface emission barrier due to the hydrogen termination.

关键词： field emission amorphous carbon hydrogen plasma treatment

Time-dependent treatment of intramolecular energy transfer for HeICl complex

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 1997年第3期15卷 218-224页

作者： Zhao, X Bu, YX Wu, AL Guan, DR SHANDONG NORMAL UNIV DEPT PHYSJINAN 250014SHANDONGPEOPLES R CHINA

The time-dependent golden wave packet method has been used for calculating the decay widths of vibrational predissociation for HeICl complex in the B state with total angular momentum J=0. This is a good example of intramolecular energy transfer, We examine the dependence of the final rotational distribution (partial decay width) of ICI fragment an the stretching excitation. It is found that computed final rotational distributions are weakly dependent on the vibrational level being excited. Unlike the smoothly varying rotational distribution for lower initial vibrational levels, for higher initial vibrational levels the rotational distribution indicates the very pronounced oscillatory structure. The analysis of the rotational distribution as a function of propagation time reveals the predominant role of the final states interaction in determining the final rotational distribution.

关键词： vibrational predissociation time-dependent wave-packet propagation

Simulation Structural Properties of Ni Clusters by Transferable Tight-binding Potential

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 1999年第4期15卷 320-322页

作者： Luo, CL Cao, AJ Zhou, YH Nanjing Normal Univ Dept Phys Nanjing 210097 Peoples R China

A transferable tight-binding potential for Ni has been developed. Molecular dynamics methods and simulated annealing techniques have been used to study the structural properties of Ni clusters with this potential. We have obtained the structures of some Ni clusters. The average coordination number, ionization potentials and the stability of clusters have also been calculated.

关键词： IONIZATION-POTENTIALS NICKEL CLUSTERS

Effect of Y_2Ba_4CuNbO_y on the Properties of Single Domain YBCO Superconductor by TSIG Process

在线全文

学校读者我要写书评

暂无评论

稀有金属材料与工程 2011年第S3期40卷 365-367页

作者： Song Fang, Yang Wanmin, Wang Miao, Li Guozheng, Wan Feng, Gao Ping, Liang Wei Shaanxi Normal University, Xi’an 710062, China Shaanxi Normal Univ Dept Phys Xian 710062 Peoples R China

The top-seeded infiltration and growth process (TSIG) is an important method to fabricate YBCO bulk superconductors. In this paper, single domain YBCO superconductors with different Gd2Ba4CuWOx (GdW2411) additions have been fabricated by TSIG process, the amount of GdW2411 added to Y2BaCuO5 (Y211) is in the range from 0wt% to 8 wt%, but there is no other additions to the liquid source. The growth morphology, microstructure and levitation force of the YBCO bulks have been investigated, it is found that the levitation force is increasing from 14 to 25 N with the increasing of GdW2411 addition from 0 to 4 wt%, and decreasing from 25 to 7 N with the increasing of GdW2411 addition from 4 to 8 wt%, the largest levitation force is obtained when the GdW2411 content is about 4 wt%. This is helpful for the fabrication of high quality YBCO bulk superconductors.

关键词： infiltration and growth YBCO single-domain Gd2Ba4CuWOx

TOPOLOGICAL STRUCTURE OF RENORM ALIZATION CONSTANTS I N QUANTUM FIELD THEORY AT SHORT DISTANCE KUNMING COLLABRATION OF MULTIHADRON DYNAMIOS

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 1991年第2期11卷 221-224页

作者：赵树松 dept. of phys. Yunnan University Kunming China

The anomalous dimensions of the quantum fields are the Hausdorff dimensiongrad. The present candidate of the renormalization constant is the generalized Cantor discontinuum. The Hausdorff dimensiongrad of the Minkowsk... 详细信息

关键词： TOPOLOGICAL STRUCTURE OF RENORM ALIZATION CONSTANTS I N QUANTUM FIELD THEORY AT SHORT DISTANCE KUNMING COLLABRATION OF MULTIHADRON DYNAMIOS 110

Effect of Y_2Ba_4CuWO_y Addition on the Properties of Single Domain YBCO Superconductors by TSIG Technique

在线全文

学校读者我要写书评

暂无评论

稀有金属材料与工程 2011年第S3期40卷 362-364页

作者： Wan Feng, Yang Wanmin, Li Guozheng, Song Fang, Gao Ping, Liang Wei Shaanxi Normal University, Xi’an 710062, China Shaanxi Normal Univ Dept Phys Xian 710062 Peoples R China

Top seeded infiltration and growth technique (TSIG) is an effective method for the preparation of high quality large YBa2Cu3O7-x (YBCO) bulk superconductors. In this paper, single domain YBCO bulk superconductors, with different Y2Ba4CuWOy (YW2411) additions, have been fabricated by TSIG process. the solid phase pellet is made of a mixture of Y2BaCuO5(Y211) + xwt% YW2411 powders, x=0, 1, 3, 5, 7, 9. The growth morphology, microstructure and levitation force of the YBCO bulks have been investigated, it is found that the levitation force is increasing from 23.05 to 33.6 N with the increasing of YW2411 addition from 0 to 5wt%, and decreasing from 33.6 to 21.59 N with the increasing of YW2411 addition from 5 to 9wt%,the largest levitation force is obtained when the YW2411 content is about 5wt%. This is very important for us to fabricate high quality YBCO bulk superconductors.

关键词： single domain YBCO bulk top seeded infiltration and growth technique Y2Ba4CuWOy addition levitation force

Modulation structure stability of heat-treated Co/C and CoN/CN soft X-ray multilayers

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1998年第1期43卷 32-36页

作者： Haili Bai Enyong Jiang Cunda Wang Renyu Tian Tianjin Univ Dept Appl Phys Tianjin 300072 Peoples R China

Modulation structure stability of Co/C and CoN/CN soft X ray multilayers has been investigated by X ray diffraction and Raman spectroscopy. The graphitization of the amorphous carbon layers in Co/C multilayers causes a period expansion of 12% at annealing temperatures below 400℃. An enormous period expansion (～40%) induced by the crystallization and agglomeration of Co layers has been observed at 500℃. While the period expansion of CoN/CN multilayers is only 4% at 400℃. The interface pattern of the CoN/CN multilayers still exists even if they were annealed at 700℃. The relatively good thermal stability of CoN/CN multilayers can be attributed to the suppression of the formation of the sp 3 bonding and, at annealing temperatures higher than the phase transition temperature of 420℃ (from hcp to fcc), the coexistence of hcp and fcc Co structures through doping nitrogen.

关键词： soft X ray multilayers annealing period expansion.

CALIBRATION AND ASSESSMENT OF MOMENT ACTUATOR

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 1999年第1期12卷 91-94页

作者： Qiu Shuye Qiu Guiming Shantou Univ Dept Phys Shantou Peoples R China

A moment actuator with direct detection of forces is *** frequency re- sponse and moment excitation purity asperformance criteria are proposed. Methods for the perfor- mancecalibration of the actuator are presented. A... 详细信息

关键词： moment actuator performance calibration reciprocity

BOUNDARY ELEMENT APPROXIMATION OF STEKLOV EIGENVALUE PROBLEM FOR HELMHOLTZ EQUATION

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 1998年第2期16卷 165-178页

作者： Tang, WJ Guan, Z Han, HD Inst Appl phys & Computat Math Lab Computat Phys Beijing 100088 Peoples R China Tsing Hua Univ Dept Appl Math Beijing 100084 Peoples R China

Steklov eigenvalue problem of Helmholtz equation is considered in the present paper. Steklov eigenvalue problem is reduced to a new variational formula on the boundary of a given domain, in which the self-adjoint property of the original differential operator is kept and the calculating of hyper-singular integral is avoided. A numerical example showing the efficiency of this method and an optimal error estimate are given.

关键词： Steklov eigenvalue problem differential operator error estimate boundary element approximation

THE BOUNDARY INTEGRO-DIFFERENTIAL EQUATIONS OF A BIHARMONIC BOUNDARY VALUE PROBLEM

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 1999年第1期17卷 59-72页

作者： Ban, HD Tang, WJ Inst Appl phys & Computat Math Lab Computat Phys Beijing 100088 Peoples R China Tsing Hua Univ Dept Appl Math Beijing 100084 Peoples R China

In this paper, a new method of boundary reduction is proposed, which reduces the biharmonic boundary value problem to a system of integro-differential equations on the boundary and preserves the self-adjointness of the original problem. Moreover, a boundary finite element method based on this integro-differential equations is presented and the error estimates of the numerical approximations are given. The numerical examples show that this new method is effective.

关键词： boundary integro-differential equations biharmonic boundary value problem