全文获取类型
收费全文 | 386600篇 |
免费 | 3835篇 |
国内免费 | 1720篇 |
专业分类
化学 | 205424篇 |
晶体学 | 5883篇 |
力学 | 18150篇 |
综合类 | 70篇 |
数学 | 44443篇 |
物理学 | 118185篇 |
出版年
2020年 | 3441篇 |
2019年 | 4023篇 |
2018年 | 5501篇 |
2017年 | 5520篇 |
2016年 | 7616篇 |
2015年 | 4333篇 |
2014年 | 7144篇 |
2013年 | 16131篇 |
2012年 | 13263篇 |
2011年 | 15986篇 |
2010年 | 11938篇 |
2009年 | 11902篇 |
2008年 | 15011篇 |
2007年 | 15005篇 |
2006年 | 13738篇 |
2005年 | 12378篇 |
2004年 | 11404篇 |
2003年 | 10170篇 |
2002年 | 10073篇 |
2001年 | 11220篇 |
2000年 | 8453篇 |
1999年 | 6277篇 |
1998年 | 5295篇 |
1997年 | 5325篇 |
1996年 | 5117篇 |
1995年 | 4458篇 |
1994年 | 4632篇 |
1993年 | 4463篇 |
1992年 | 4908篇 |
1991年 | 5057篇 |
1990年 | 4823篇 |
1989年 | 4780篇 |
1988年 | 4651篇 |
1987年 | 4571篇 |
1986年 | 4503篇 |
1985年 | 5801篇 |
1984年 | 5900篇 |
1983年 | 4952篇 |
1982年 | 5133篇 |
1981年 | 4899篇 |
1980年 | 4503篇 |
1979年 | 5014篇 |
1978年 | 5184篇 |
1977年 | 5336篇 |
1976年 | 5413篇 |
1975年 | 4962篇 |
1974年 | 4988篇 |
1973年 | 5136篇 |
1972年 | 3907篇 |
1971年 | 3402篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
N. Monnanteuil J.M. Colmont 《Journal of Quantitative Spectroscopy & Radiative Transfer》1983,29(2):131-136
Self broadened widths of seven lines of ozone between 75 and 120 GHz have been measured at room temperature. The variation with temperature of the self-broadening parameter for three of these lines has been studied in the range 245–292°K. 相似文献
72.
73.
N. O. Maksimova 《Journal of Mathematical Sciences》2006,135(1):2675-2679
In the article, it is proved that any nonnegative solution of an elliptic quasilinear inequality that vanishes on a subset
of positive measure is trivial.
__________
Translated from Trudy Seminara imeni I. G. Petrovskogo, No. 25, pp. 112–118, 2005. 相似文献
74.
75.
Gabriel N. Gatica Ernst P. Stephan 《Numerical Methods for Partial Differential Equations》2002,18(1):105-128
This article deals with an expanded mixed finite element formulation, based on the Hu‐Washizu principle, for a nonlinear incompressible material in the plane. We follow our related previous works and introduce both the stress and the strain tensors as further unknowns, which yields a two‐fold saddle point operator equation as the corresponding variational formulation. A slight generalization of the classical Babu?ka‐Brezzi's theory is applied to prove unique solvability of the continuous and discrete formulations, and to derive the corresponding a priori error analysis. An extension of the well‐known PEERS space is used to define an stable associated Galerkin scheme. Finally, we provide an a posteriori error analysis based on the classical Bank‐Weiser approach. © 2002 John Wiley & Sons, Inc. Numer Methods Partial Differential Eq 18: 105–128, 2002 相似文献
76.
S. V. Ivanov V. V. Trachevskii O. S. Titova L. A. Zozulya 《Russian Journal of Applied Chemistry》2006,79(10):1712-1714
Experimental data demonstrate that a study of accelerated aging can enable prognostication of the working capacity and storage life of polymeric formulations used in aircraft components on the basis of changes in thermogravimetric constants of these polymeric formulations. 相似文献
77.
78.
V. A. Zayats A. N. Nikolaevskii T. A. Filippenko O. P. Kniga G. A. Tikhonova 《Russian Journal of Applied Chemistry》2006,79(10):1651-1654
Specific features of the initiated oxidation of polyethylene and its low-molecular-weight analogue tridecane, associated with the occurrence of the process in the short-chain mode, were studied. 相似文献
79.
R. L. Moreira P. Saint-Grgoire M. Lopez M. Latour 《Journal of Polymer Science.Polymer Physics》1989,27(3):709-722
The thermal and dielectric behaviors of poly(vinylidene fluoride-trifluoroethylene) copolymers near the ferroelectric-to-paraelectric phase transition are investigated for samples with 20, 25, 30, and 40 mol% trifluoroethylene (TrFE). The data suggest that the transition becomes continuous for a particular composition near 50 mol% TrFE. Experimental data are sensitive to thermal history (kinetics of crystallization, and kinetics and cycling over the structural transition). It is found that several anomalies are present at the structural change, and in particular the 30 mol% TrFE sample shows the most marked anomalies. These phenomena can be attributed to defects, but another possibility would be the existence of an intemediate supplementary phase. Both hypotheses are discussed. 相似文献
80.