检索结果-南通市图书馆

中国有色金属学会会刊：英文版 1999年第S1期9卷 355-363页

作者： Alan L. Dragoo Division of Materials sciences, Office of Basic Energy sciences, u.s.Department of Energy, Germantown, MD 2087-1290, u.s.a.

Progress has been made in intermetallic alloys over the past decade and a half, but intermetallics remain a relatively unexplored class of materials for energy applications. Hence, they offer considerable opportunities both for scientific research on fundamental structural property processing relationships and for technological development. The Department of Energy supports a program of scientific research on intermetallic alloys such as the nickel and iron aluminides and is establishing new research efforts in silicides and Laves phases through the program of the Division of Materials sciences, of the Office of Basic Energy sciences. Areas of research include theory and materials simulation, microalloying, high resolution sudies of structure and composition, mechanical properties, point defects and dislocation mechanics, phase transformations, and processing. Research is conducted through programs at the Department of Energy National Laboratories and through grants to academic and industrial *** results from Division of Materials sciences programs have provided the basis and transportation. In addition, a cooperative effort between research groups has been established as a project on intermetallic materials under the Center of Excellence in synthesis and Processing of Advanced Materials.

关键词： intermetallics energy applications nickel aluminides iron aluminides silicides Laves phases

u.s. Department of Energy Research in Intermetallic Alloys and Composites

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica sinica(English Letters) 1995年第Z1期8卷 615-624页

作者： Alan L. Dragoo (Division of Materials sciences Office of Basic Energy sciences u.s.Department of Energy Washington, D.C.20585) u.s.a.

The program of the Division of Materials sciences *** materials will be surveyed. This program is carried out at Department of Energy National Laboratories and at u.s. universities. Areas of research include theory and material simulation, microalloying, high resolution studies of structure and composition, mechanical properties, point defects and dislocation mechanics, phase transformations, and processing. Finally, general considerations will be discussed for the future program.

关键词： Department of Energy Research in Intermetallic Alloys and Composites

ON THE hp FINITE ELEMENT METHOD FOR THE ONE DIMENsIONAL sINGuLARLY PERTuRBED CONVECTION-DIFFusION PROBLEMs

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2002年第6期20卷 599-610页

作者： Zhi-min Zhang (Department of Mathematics, Wayne state university, Detroit, MI 48202, u.s.a.) Department of Mathematics Wayne State University 美国 Detroit MI 48202

Presents information on singularly peturbed two-point boundary value problem of convection-diffusion type. Analysis of the problem; Details of an hp version finite element method on a strongly graded piecewise uniform... 详细信息

关键词： hp-version finite element methods convection-diffusion singularly perturbed exponential rate of convergence.

Quantum mechanical reaction dynamics in collisions of chlorine atom with hydrogen molecule

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 1994年第3期12卷 213-222页

作者： Meishan ZHAO The James Franck Institute, the university of Chicago, Chicago, Illinois 60637, u.s.a. The James Franck Institute the University of Chicago Chicago Illinois 60637 U.S.A.

We report the accurate determinations of quantum mechanical state-to-state probabilities tor reactions Cl + H2 - HCl + H and H' + HCl - H'Cl + H by the generalized Newton variational principle, on the most accurate available potential energy surface. We compare the results for three versions of realistic potential energy surfaces, and to those from hyperspherical close-coupling calculations.

关键词： Triatomic collision reactive scattering Green's function reactance matrix scattering matrix reactive transition probability.

Effect of intramolecular energy transfer on the rate of unimolecular isomerization: HCN --HNC

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 1995年第2期13卷 141-149页

作者： ZHAO, Mei-shan The James Franck Institute, The university of Chicago, Chicago, IL 60637, u.s.a. The James Franck Institute The University of Chicago Chicago IL 60637 U.S.A.

This paper reports calculations of the rate of isomerization of HCN - HCN based on the theory of Gary and Rice as extended by Zhao and Rice. The major task is to determine the effect of intramolecular energy transfer on the prediction of the rate of isomerization. Both the full three-dimensional (3D) system and the reduced two-dimensional (2D) system obtained from freezing CN bond at 1.159 A are analyzed to check the validity of the freezing bond approximation. Meanwhile, RRKM rates are calculated to test RRKM choice of the transition state by comparing to Gary-Rice three-state model. The comparison shows that the rates from 2D model and 3D model are differing up to 20% with 2D rates consistently larger. The intramolecular energy transfer modifies the isomerization rate for HCN system up to 30% that is modestly small by the expectation. The isomerization rate predicted from RRKM theory is greater than those of Gary-Rice three-state model theory up to 65%, and it overstimates the rates under all considerations, including the contribution from intramolecular energy transfer, for the studied system by about a factor of 2.

关键词： Nonlinear dynamics bottleneck separatrix Poincare surface of section quasiperi-odic chaotic unimolecular isomerization rate.

550 AND 450°C IsOTHERMAL sECTIONs OF Fe-Ni-C PHAsE DIAGRAM

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica sinica(English Letters) 1992年第12期5卷 471-475页

作者： GONG Fangyuc Tianjin university,Tianjin,China JI GOLDsTEIN LChigh university Bethlchem,u.s.a. Tianjin univ Tianjin China

By using WDs method of EPMA and EDs tecbnique of sTEM.550 and 450℃ isother- mal sections of Fe-Ni-C phase diagram were determined.

关键词： Fe-Ni-C system phase diagram isothermal section

BIOGEOGRAPHY AND PHYLOGENY OF THE sEA-sKATER HALOBATEs

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Oceanology and Limnology 1989年第3期7卷 233-239页

作者： Lanna Cheng (A - 002 scripps Institution of Oceanography La Jolla, California 92093 , u.s.a. ) A-002 scripps Institution of Oceanography La Jolla U.S.A.

Members of the genus Halobates are the only insects to be found in the open oceans .generally roughly between latitudes 40°N and 40°s . Of the 40 - odd species , only five (Halobates means. H- sericeus. H. germanus. H . sobrinus and H. splendens tare pelagic > the others being found in near - shore habitats . often endemic to islands or island groups. H. means is the only cosmopolitan species, being found in the Atlantic . Pacific and Indian Oceans . All five species are found in the Pacific Ocean but only two , Halobates means and Halobates germanus. occur also in the Indian Ocean .Their ranges of distribution are probably limited by physical as well as historical factors .Halobates probably originated from a near - shore brackish - water ancestor in the Indo - Malaysian region . This is the area where the majority of the near - shore sea - skater species are found ;it is also where related brackish - water genera (Asclepios , etc . )occur . There are indications that the open - ocean H alobates

关键词： probably genera Hemiptera originated endemic shore ocean splendens Atlantic historical

use of a Laser/TIG Combination for surface Modification of Ti-6Al-4V Alloy

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2期17卷 237-239页

作者： M.Labudovic and R.Kovacevic southern Methodist university, Dept. of Mechanical Engineering, Dallas, Texas, u.s.a. Dept. of Mech. Eng. Southern Methodist Univ. Dallas United States

The surface modification of materials such as Ti-6Al-4V is necessary to improve their wear resistant properties for use in tribological applications. In this paper it is shown that a laser with low power and tungsten inert gas (TIG) can be combined together for surface modification of Ti-6Al-4V alloy, and when performed in a controlled atmosphere of pure nitrogen or a mixture of nitrogen and argon, can produce a wear-resistant surface alloy. Compared with laser processing, a cheaper surface modification process has been developed involving a shorter processing time, which is free of stringent requirements such as a vacuum system.

关键词： Ti TIG use of a Laser/TIG Combination for surface Modification of Ti-6Al-4V Alloy Al

Effects of Ta Addition on Microstructure and Transformation Behavior of Ni-Ti Alloys

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1期17卷 5-6页

作者： K.H.Wu and JL.Ma Department of Mechanical Engineering, Florida International university, Miami, FL 33174, u.s.a. Dep. of Mech. Eng. Florida Int. Univ. Miami 33174 United States

The effect of adding Ta on the changes of microstructure and Ms temperature of a dualphase shape memory alloy with compositions of (Ni51 Ti49)1 -***. and Ni50-Ti50 -***.g were systematically studied. An optical microscope, sEM, X-ray diffraction and DsC were utilized in this work. The evolution of the microstructure as a function of Ta content was characterized. The variation of the Ni/Ti ratio in the NiTi phase plays an important role in the change of the Ms temperatures due to the addition of Ta. A pseudobinary NiTi-Ta phase diagram was proposed based on these results.

关键词： Ti Ta Effects of Ta Addition on Microstructure and Transformation Behavior of Ni-Ti Alloys

关于中国公共图书馆同美国公共图书馆相比较的思考

在线全文

学校读者我要写书评

暂无评论

图书情报工作 2001年第2期45卷 10-12,79页

作者：包学鸣美国西东大学图书馆

从中国公共图书馆超过美国公共图书馆的方面、同美国公共图书馆相似的方面和与美国公共图书馆不同的方面这三个角度进行比较;通过比较,可使人们对中国公共图书馆近些年取得的成就和存在的问题有个客观的了解,同时也对美国公共图书馆的... 详细信息

从中国公共图书馆超过美国公共图书馆的方面、同美国公共图书馆相似的方面和与美国公共图书馆不同的方面这三个角度进行比较;通过比较,可使人们对中国公共图书馆近些年取得的成就和存在的问题有个客观的了解,同时也对美国公共图书馆的情况有所了解。

关键词：中国美国公共图书馆比较分析