全文获取类型
收费全文 | 20677篇 |
免费 | 157篇 |
国内免费 | 89篇 |
专业分类
化学 | 10518篇 |
晶体学 | 419篇 |
力学 | 607篇 |
综合类 | 7篇 |
数学 | 1726篇 |
物理学 | 7646篇 |
出版年
2017年 | 157篇 |
2016年 | 246篇 |
2015年 | 168篇 |
2014年 | 271篇 |
2013年 | 847篇 |
2012年 | 590篇 |
2011年 | 648篇 |
2010年 | 467篇 |
2009年 | 478篇 |
2008年 | 631篇 |
2007年 | 683篇 |
2006年 | 647篇 |
2005年 | 596篇 |
2004年 | 512篇 |
2003年 | 476篇 |
2002年 | 477篇 |
2001年 | 692篇 |
2000年 | 516篇 |
1999年 | 432篇 |
1998年 | 351篇 |
1997年 | 334篇 |
1996年 | 306篇 |
1995年 | 382篇 |
1994年 | 353篇 |
1993年 | 322篇 |
1992年 | 348篇 |
1991年 | 391篇 |
1990年 | 363篇 |
1989年 | 365篇 |
1988年 | 336篇 |
1987年 | 337篇 |
1986年 | 331篇 |
1985年 | 407篇 |
1984年 | 424篇 |
1983年 | 320篇 |
1982年 | 330篇 |
1981年 | 351篇 |
1980年 | 325篇 |
1979年 | 336篇 |
1978年 | 335篇 |
1977年 | 314篇 |
1976年 | 332篇 |
1975年 | 290篇 |
1974年 | 283篇 |
1973年 | 302篇 |
1972年 | 182篇 |
1969年 | 159篇 |
1968年 | 190篇 |
1967年 | 335篇 |
1966年 | 284篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
We consider multi-component electrolyte solutions and plasmas in thermal equilibrium and define thermodynamic quantities for number densities which do not necessarily satisfy the condition of charge neutrality. It is shown that these quantities play a role in compressibility theorems for the pair correlation functions and in the generalized Debye shielding length. A fourth moment condition for the pair correlation functions is derived. We discuss to what extent non-uniform systems may be described in terms of local thermodynamics with added coulomb interactions. 相似文献
993.
U. P. Vagin E. S. Kolodochkin A. N. Karkhov N. L. Stal’ 《Russian Journal of Physical Chemistry B, Focus on Physics》2013,7(6):671-673
The paper describes a space monitoring system for powerful impulsive sources designed for detecting storm fronts and lightning activity, predicting powerful magnetic storms, and analyzing the characteristics of faults in the Earth’s curst. It is shown that onboard apparatus can also be used to detect solar and Galactic ionizing-radiation activity, determine the total electron content in the ionosphere, etc. In conclusion, examples of social-economic problems that can be solved using the impulsive-source monitoring system are presented, and perspectives for the further development of this system are discussed. 相似文献
994.
A. Yu. Spivak D. A. Nedopekina E. R. Shakurova R. R. Khalitova R. R. Gubaidullin V. N. Odinokov U. M. Dzhemilev Yu. P. Bel’skii N. V. Bel’skaya S. A. Stankevich E. V. Korotkaya V. A. Khazanov 《Russian Chemical Bulletin》2013,62(1):188-198
New derivatives of lupane triterpenoids, viz., 20,29-dihydrobetulinic and 3-epi-20,29-dihydrobetulinic acid derivatives containing triphenylphosphonium fragments as substituents were synthesized. These compound considerably exceed betulinic acid in antitumor activity. 相似文献
995.
996.
Sachin U. Nandanwar Kai Coldsnow Vivek Utgikar Piyush Sabharwall D. Eric Aston Yanning Zhang 《Adsorption》2016,22(2):129-137
Hollow carbon nano-polyhedrons (HCNPHs) supported on Engelhard Titanosilicate-10 (ETS-10) were synthesized by wet impregnation technique using tetrahydrofuran as a solvent. Synthesized HCNPHs/ETS-10 nanosorbent was characterized by X-ray diffraction, Raman spectra, N2-adsorption–desorption isotherm, BET surface area, and scanning electron microscopy to confirm the morphology and uniformity of carbon particles ranging from 50 to 70 nm in diameter. Sorption characteristics of this nanosorbent for krypton at various carbon loadings were determined using a bench-scale column apparatus. The dynamic sorption capacity of HCNPHs/ETS-10 nanosorbent calculated from the breakthrough curve, 0.75 mmol/kg, which was ~15 % higher than for that of activated carbon. The effect of temperature on the adsorption capacity was studied between 263–293 K. Operational capacity of the nanosorbent was found to be 0.45 mmol/kg at 263 K. The experimental results indicate that 10 wt% HCNPHs/ETS-10 nanosorbent showed promising results for krypton adsorption, indicating its potential as an economical and active sorbent for krypton removal from the off-gas streams resulting from operations for recycle of used nuclear fuel. 相似文献
997.
998.
999.
Mechanics of Composite Materials - The shapes of force–displacement curves recorded in single-fiber pullout and microbond tests are analyzed within the framework of a stress-based model of... 相似文献
1000.
Eric C. Chi Liuyi Hu Arvind K. Saibaba Arvind U. K. Rao 《Journal of computational and graphical statistics》2019,28(1):36-47
We consider the problem of performing matrix completion with side information on row-by-row and column-by-column similarities. We build upon recent proposals for matrix estimation with smoothness constraints with respect to row and column graphs. We present a novel iterative procedure for directly minimizing an information criterion to select an appropriate amount of row and column smoothing, namely, to perform model selection. We also discuss how to exploit the special structure of the problem to scale up the estimation and model selection procedure via the Hutchinson estimator, combined with a stochastic Quasi-Newton approach. Supplementary material for this article is available online. 相似文献