全文获取类型
收费全文 | 4723篇 |
免费 | 451篇 |
国内免费 | 319篇 |
专业分类
化学 | 1427篇 |
晶体学 | 37篇 |
力学 | 832篇 |
综合类 | 55篇 |
数学 | 2531篇 |
物理学 | 611篇 |
出版年
2024年 | 7篇 |
2023年 | 43篇 |
2022年 | 63篇 |
2021年 | 108篇 |
2020年 | 95篇 |
2019年 | 70篇 |
2018年 | 118篇 |
2017年 | 129篇 |
2016年 | 174篇 |
2015年 | 116篇 |
2014年 | 154篇 |
2013年 | 382篇 |
2012年 | 201篇 |
2011年 | 193篇 |
2010年 | 209篇 |
2009年 | 249篇 |
2008年 | 232篇 |
2007年 | 264篇 |
2006年 | 262篇 |
2005年 | 262篇 |
2004年 | 241篇 |
2003年 | 230篇 |
2002年 | 220篇 |
2001年 | 153篇 |
2000年 | 176篇 |
1999年 | 178篇 |
1998年 | 134篇 |
1997年 | 130篇 |
1996年 | 83篇 |
1995年 | 86篇 |
1994年 | 78篇 |
1993年 | 70篇 |
1992年 | 68篇 |
1991年 | 56篇 |
1990年 | 39篇 |
1989年 | 23篇 |
1988年 | 30篇 |
1987年 | 24篇 |
1986年 | 24篇 |
1985年 | 28篇 |
1984年 | 22篇 |
1983年 | 9篇 |
1982年 | 18篇 |
1981年 | 13篇 |
1980年 | 8篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1976年 | 5篇 |
1957年 | 1篇 |
排序方式: 共有5493条查询结果,搜索用时 15 毫秒
51.
Non-compact generalized variational inequalities for quasi-monotone and hemi-continuous operators with applications 总被引:1,自引:0,他引:1
Some results are obtained for non-compact cases in topological vector spaces for the existence problem of solutions for some
set-valued variational inequalities with quasi-monotone and lower hemi-continuous operators, and with quasi-semi-monotone
and upper hemi-continuous operators. Some applications are given in non-reflexive Banach spaces for these existence problems
of solutions and for perturbation problems for these set-valued variational inequalities with quasi-monotone and quasi-semi-monotone
operators.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
52.
王海舟 《中国科学B辑(英文版)》2003,46(2)
The property of the material is closely related to its chemical compositions and microstruc-tures, which are the important parameters in the judgement of the quality of the material. The conventional chemical composition content of the material is an average value of the chemical composition of the whole material tested or the content of a fix position. Although it is still neces-sary to further improve these conventional methods, there are mature and systematic methods for analyzing the conve… 相似文献
53.
研究了Banach空间中拟-似变分包含解的存在与逼近问题.给出了一种寻求解的新的迭代算法,建立了具混合误差的Ishikawa型迭代序列强收敛到解的充要条件.所得结果推广了一些相关的结果. 相似文献
54.
Preparation of Papers 总被引:8,自引:0,他引:8
We motivate the study of a vector variational inequality by a practical flow equilibrium problem on a network, namely a generalization of the well-known Wardrop equilibrium principle. Both weak and strong forms of the vector variational inequality are discussed and their relationships to a vector optimization problem are established under various convexity assumptions. 相似文献
55.
A special two-sided condition for the incremental magnetic reluctivity is introduced which guarantees the unique existence of both the weak and the approximate solutions of the nonlinear stationary magnetic field distributed on a region composed of different media, as well as a certain estimate of the error between the two solutions. The condition, being discussed from the physical as well as the mathematical point of view, can be easily verified and is fulfilled for various magnetic reluctivity models used in electrotechnical practice. 相似文献
56.
Heng-You Lan 《Journal of Mathematical Analysis and Applications》2007,327(1):481-493
In this paper, we introduce and study a new system of nonlinear A-monotone multivalued variational inclusions in Hilbert spaces. By using the concept and properties of A-monotone mappings, and the resolvent operator technique associated with A-monotone mappings due to Verma, we construct a new iterative algorithm for solving this system of nonlinear multivalued variational inclusions associated with A-monotone mappings in Hilbert spaces. We also prove the existence of solutions for the nonlinear multivalued variational inclusions and the convergence of iterative sequences generated by the algorithm. Our results improve and generalize many known corresponding results. 相似文献
57.
Meng F. Q. Lu M. K. Yang Z. H. Zeng H. 《Journal of Thermal Analysis and Calorimetry》1998,52(2):609-613
The thermal behavior of two new non-linear optical (NLO) materials, urea-(D) tartaric acid (UDT) and urea-(DL) tartaric acid
(UDLT) were studied by using DSC, TG and TMA. The results show that: 1) The two crystals have different melting points but
similar decomposition temperatures due to the influences of intermolecular forces, which is attributed to the stereo effects
of (D)-tartaric and (DL)-tartaric acid molecules; 2) There was only thermal expansion and no thermal contraction when the
UDT and UDLT crystals were heated; 3) There was no phase transition within the measured temperature range; 4) The thermal
expansion of the UDT and UDLT crystals shows a small anisotropy; 5) The specific heats of UDT and UDLT change linearly with
temperature in the measured temperature range and the value for UDT is 1.321 J g-1 K-1 at 320 K while the specific heat of
UDLT is 1.357 J g-1 K-1 at the same temperature.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
58.
张昌斌 《纯粹数学与应用数学》1998,14(3):21-24,71
借助于文(1)中的结论研究了仿紧集上的拟-似变分不等式,统一和发展了文(2-6)中的相应结果。 相似文献
59.
A. Bachem W. Hochstättler B. Steckemetz A. Volmer 《Computational Optimization and Applications》1996,6(3):213-225
We report on computational experience with an implementation of three algorithms for the general economic equilibrium problem. As a result we get that the projection algorithm for variational inequalities increases the size of solvable models by a factor of 5–10 in comparison with the classical homotopy method. As a third approach we implemented a simulated annealing heuristic which might be suitable to estimate equilibria for very large models.Supported by the German Research Association (Deutsche Forschungsgemeinschaft, SFB 303). 相似文献
60.
In this paper, we prove a uniqueness theorem for a free boundary problem which is given in the form of a variational inequality. This free boundary problem arises as the limit of an equation that serves as a basic model in population biology. Apart from the interest in the problem itself, the techniques used in this paper, which are based on the regularity theory of variational inequalities and of harmonic functions, are of independent interest, and may have other applications.