全文获取类型
收费全文 | 255961篇 |
免费 | 6105篇 |
国内免费 | 4732篇 |
专业分类
化学 | 120316篇 |
晶体学 | 3637篇 |
力学 | 15322篇 |
综合类 | 323篇 |
数学 | 42476篇 |
物理学 | 84724篇 |
出版年
2022年 | 1961篇 |
2021年 | 2701篇 |
2020年 | 3102篇 |
2019年 | 3371篇 |
2018年 | 11934篇 |
2017年 | 12462篇 |
2016年 | 8851篇 |
2015年 | 3898篇 |
2014年 | 4978篇 |
2013年 | 7897篇 |
2012年 | 11534篇 |
2011年 | 19638篇 |
2010年 | 12915篇 |
2009年 | 13088篇 |
2008年 | 16868篇 |
2007年 | 19878篇 |
2006年 | 6457篇 |
2005年 | 11313篇 |
2004年 | 7951篇 |
2003年 | 7754篇 |
2002年 | 6068篇 |
2001年 | 4712篇 |
2000年 | 3776篇 |
1999年 | 2766篇 |
1998年 | 2597篇 |
1997年 | 2273篇 |
1996年 | 2282篇 |
1995年 | 1922篇 |
1994年 | 1971篇 |
1993年 | 1905篇 |
1992年 | 1917篇 |
1991年 | 2030篇 |
1990年 | 1968篇 |
1989年 | 1917篇 |
1988年 | 1751篇 |
1987年 | 1693篇 |
1986年 | 1644篇 |
1985年 | 1796篇 |
1984年 | 1913篇 |
1983年 | 1663篇 |
1982年 | 1678篇 |
1981年 | 1484篇 |
1980年 | 1403篇 |
1979年 | 1609篇 |
1978年 | 1757篇 |
1977年 | 1678篇 |
1976年 | 1739篇 |
1975年 | 1580篇 |
1974年 | 1623篇 |
1973年 | 1639篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
D. N. Emel’yanov N. V. Volkova O. I. Sheronova Z. G. Chernorukova 《Russian Journal of Applied Chemistry》2006,79(8):1354-1359
The process of preservation of newspaper with aqueous solutions and dispersions of acrylic copolymers is considered from the instant of impregnation till removal of the polymeric preservative from paper. 相似文献
952.
Yu. V. Sokolova 《Russian Journal of Applied Chemistry》2006,79(4):573-578
Kinetics of Sc(III) sorption from hydrochloric acid solutions on KRF-20t-60 cation exchanger is studied. The experimental data are analyzed in terms of the gel and film kinetic models. The Sc(III) diffusion coefficient in the resin phase is estimated. Static and dynamic sorption data are obtained on Sc(III) sorption from various process solutions on KRF-20t-60, PA-1, AFI-22 ion exchangers, and also on ion exchangers supported on polyacrylonitrile-based fibrous material. Desorption of Sc(III) from KRF-20t-60 is also studied. 相似文献
953.
S. Yu. Orevkov 《Proceedings of the Steklov Institute of Mathematics》2006,253(1):123-143
A negative answer is given to the following question of A.G. Vitushkin: Does there exist a nontrivial lower bound for the
length of the maximal component of intersection of the unit sphere and an algebraic curve passing through the origin.
Published in Russian in Trudy Matematicheskogo Instituta imeni V.A. Steklova, 2006, Vol. 253, pp. 135–157.
To the memory of Anatolii Georgievich Vitushkin 相似文献
954.
The objective of this paper is to analyze under what well-known operations the class of quasipolyhedral convex functions,
which can be regarded as an extension of that of polyhedral convex functions, is closed. The operations that will be considered
are those that preserve polyhedral convexity, such that the image and the inverse image under linear transformations, right
scalar multiplication (including the case where λ=0+) and pointwise addition.
相似文献
955.
956.
This paper presents results of studies on dc electrical conductivity and transference number measurements on potassium bromate
(KBrO3) complexed polyvinyl chloride (PVC) films prepared by solution cast technique. Temperature dependence of dc electrical conductivity
and transference number data indicated the dominance of ion type charge transport in these specimens. The magnitude of conductivity
increased with increase in concentration of the salt and temperature. Using this (PVC + KBrO3) electrolyte, solid-state electrochemical cells were fabricated, and their discharge profiles were studied under a constant
load of 100 kΩ. Several cell profiles such as open circuit voltage, short circuit current, power density, and energy density
associated with these cells were evaluated and were reported. The features of complexation of the electrolytes were studied
by X-ray diffraction and Fourier transform infrared spectroscopy.
Paper presented at the Third International Conference on Ionic Devices (ICID 2006), Chennai, Tamilnadu, India, Dec. 7–9, 2006 相似文献
957.
Augustine O. Esogbue Qiang Song Donovan Young 《Mathematical Methods of Operations Research》2006,63(3):525-542
In this paper the problem of verifying the Pareto-optimality of a given solution to a dynamic multiple-criterion decision (DMCD) problem is investigated. For this purpose, some new conditions are derived for Pareto-optimality of DMCD problems. In the literature, Pareto-optimality is characterized by means of Euler-Lagrangian differential equations. There exist problems in production and inventory control to which these conditions cannot be applied directly (Song 1997). Thus, it is necessary to explore new conditions for Pareto-optimality of DMCD problems. With some mild assumptions on the objective functionals, we develop necessary and/or sufficient conditions for Pareto-optimality in the sprit of optimization theory. Both linear and non-linear cases are considered. 相似文献
958.
959.
D. Fong J. H. Hamilton A. V. Ramayya J. K. Hwang C. Goodin K. Li J. Kormicki J. O. Rasmussen Y. X. Luo S. C. Wu I. Y. Lee A. V. Daniel G. M. Ter-Akopian G. S. Popeko A. S. Fomichev A. M. Rodin Yu. Ts. Oganessian M. Jandel J. Kliman L. Krupa J. D. Cole M. A. Stoyer R. Donangelo W. C. Ma 《Physics of Atomic Nuclei》2006,69(7):1161-1167
The hot bimodal fission of 252Cf is reexamined with new high-statistics data. We constructed a γ-γ-γ coincidence cube for binary fission and LCP-gated γ-γ matrix for ternary fission. By identifying the secondary fission fragments from their γ-ray transitions, we measured the yields for various fission splits. The normal neutron yield distribution is found to be
Gaussian for Xe-Ru. However, the binary fission split of Ba-Mo is found to exhibit a bimodal neutron distribution with the
“hot mode” corresponding to ≈3.1% of the total yield. In α ternary fission, the first measurements of yields for specific fission splits are presented. The Te-α-Ru and Xe-α-Mo neutron yields fit well with a single mode, but the Ba-α-Zr split shows evidence for an enhanced hot mode with an intensity of ≈13.8% of the normal mode.
The text was submitted by the authors in English. 相似文献
960.
I. G. Silinskaya A. V. Novoselova Yu. N. Sazanov A. V. Gribanov I. N. Serov V. I. Margolin 《Russian Journal of Applied Chemistry》2006,79(8):1378-1380
Mechanisms of orientation for the solutions of polyacrylonitrile synthesized under conditions of radical and anionic polymerization were studied. The effect of the fractal-matrix structuring agent developed by the AIRES foundation on the correlation parameters of the solution density and average squared fluctuation polarizability, which can be used to determine how the supramolecular structure changes by “self-orientation” and “induced orientation” mechanisms, was analyzed. 相似文献