首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   374篇
  免费   2篇
化学   204篇
晶体学   5篇
力学   47篇
数学   19篇
物理学   101篇
  2021年   6篇
  2020年   9篇
  2019年   7篇
  2018年   7篇
  2017年   5篇
  2016年   10篇
  2015年   4篇
  2014年   3篇
  2013年   9篇
  2012年   17篇
  2011年   15篇
  2010年   17篇
  2009年   17篇
  2008年   13篇
  2007年   16篇
  2006年   6篇
  2005年   7篇
  2004年   15篇
  2003年   9篇
  2002年   10篇
  2001年   10篇
  2000年   7篇
  1999年   3篇
  1998年   5篇
  1997年   7篇
  1996年   10篇
  1995年   5篇
  1994年   6篇
  1993年   3篇
  1992年   3篇
  1991年   10篇
  1990年   4篇
  1989年   5篇
  1988年   4篇
  1987年   9篇
  1986年   5篇
  1985年   5篇
  1984年   5篇
  1982年   3篇
  1980年   4篇
  1977年   3篇
  1975年   3篇
  1973年   3篇
  1972年   3篇
  1971年   4篇
  1970年   4篇
  1969年   10篇
  1968年   4篇
  1967年   6篇
  1966年   6篇
排序方式: 共有376条查询结果,搜索用时 203 毫秒
1.
Russian Physics Journal - The results of model experimental studies of structural-phase changes in an AA2024 aluminum alloy after friction with a counter-body of a complex configuration are...  相似文献   
2.
Russian Physics Journal - Using a simultaneous electrical explosion of two twisted wires, bimetallic Ti–Ag and Fe–Ag nanoparticles are synthesized, where the component ratios are...  相似文献   
3.
New 4-aryl-2-(4-arylamino)-1-(piperazin-1-yl)but-2-ene-1,4-diones and 2-{[2-(3-R-adamantan-1-yl)-2-oxoethylidene]hydrazinyl}-4-(het)aryl-4-oxobut-2-enoic acids were synthesized and used to obtain water-soluble compounds. Their influence on the blood coagulation system was studied, which revealed compounds with a high hemostatic activity and a low acute toxicity. A relationship between structure and pharmacological effect of the synthesized compounds was established.  相似文献   
4.
The paper discusses the scaled-boundary method as applied to electroelastic problems. As an example, the stress-intensity factor is calculated for a thin rectangular piezoelectric plate with an edge crack __________ Translated from Prikladnaya Mekhanika, Vol. 42, No. 7, pp. 124–134, July 2006.  相似文献   
5.
An investigation is conducted in the solution of a number of practical problems of the radiative and combined heat exchange in nonuniform systems having widely different physical properties. The processes of thermal interaction between the ocean and the atmosphere have been treated in the paper [1], the effect of thermal radiation on the melting and solidification of semitransparent crystals has been investigated in [2], the flow of a selectively emitting gas around the lateral surface of an object evaporating under the action of radiative heating has been discussed in [3], and heat transfer from a jet to the molten mass of glass in a glassmaking furnace tank has been investigated in [4]. The radiative and combined heat exchange between a selectively emitting liquid and a transparent heat-conducting laminar gas flow in the case of a specified external thermal radiation field is discussed in this paper. The energy conservation equations are set up taking into account the heat transfer by radiation, convection, and molecular thermal conduction. A differential approximation is used in calculating the values of the radiation fluxes. A system of fundamental computational equations is solved by the method of finite differences and iterations and by the Runge-Kutta method. The results of the calculations are presented in the form of graphs.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 3, pp. 116–122, May–June, 1976.  相似文献   
6.
A conjugate problem of radiative–convective heat transfer in a turbulent hightemperature gasdisperse flow around a thermally thin ablating plate is considered. The plate experiences intense radiative heating by an external source, which is a blackbody. The temperature fields and the distributions of heat fluxes along the plate under unsteady conditions are calculated. The data gained make it possible to examine the effect of the Stark number and phasetransition heat in the plate material on the time evolution of the thermal state of the boundarylayer medium and the plate itself being heated by a hightemperature radiation source.  相似文献   
7.
Numerical modeling of the single-phase Stefan problem in a semitransparent layer with transparent, nonabsorbing, and partially radiation-absorbing boundaries is performed. It is shown that at low temperatures of the medium, convection is a determining factor on the boundary of the irradiated sample, and at high temperatures, radiation is predominant. The absence of absorption on the boundaries of the layer leads to acceleration of the heating of the plate and considerable deceleration of melting processes. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 3, pp. 84–91, May–June, 2006.  相似文献   
8.
It was shown that the synthesis of Cu nanopowder by thermal decomposition afforded chemically purer (without oxides) and finer (specific surface value ~45 m2 g?1) product than the synthesis by chemical reduction. The latter method leads to pyrophoric nanopowders containing detectable amounts of copper oxides.  相似文献   
9.
Model interpretation of heating and melting processes is analyzed in application to the onephase statement of Stefan problem in a flat layer of semitransparent material heated from one side, and melted by the radiation-convective method.  相似文献   
10.
The recyclization of 2-{[5-aryl-2-oxofuran-3(2H)-ylidene]amino}thiophene-3-carboxylic acids with cyano-acetic acid derivatives in the presence of t-BuOK afforded potassium 1-cyano-3-{[5-R1-4-R2-3-(ethoxycarbonyl)-thiophen-2-yl]amino}-1-R3-5-oxo-5-arylpenta-1,3-dien-2-olates.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号