全文获取类型
收费全文 | 3842篇 |
免费 | 145篇 |
国内免费 | 28篇 |
专业分类
化学 | 2558篇 |
晶体学 | 33篇 |
力学 | 109篇 |
综合类 | 3篇 |
数学 | 626篇 |
物理学 | 686篇 |
出版年
2023年 | 23篇 |
2022年 | 110篇 |
2021年 | 118篇 |
2020年 | 86篇 |
2019年 | 115篇 |
2018年 | 115篇 |
2017年 | 95篇 |
2016年 | 152篇 |
2015年 | 130篇 |
2014年 | 166篇 |
2013年 | 277篇 |
2012年 | 287篇 |
2011年 | 301篇 |
2010年 | 190篇 |
2009年 | 143篇 |
2008年 | 208篇 |
2007年 | 172篇 |
2006年 | 172篇 |
2005年 | 167篇 |
2004年 | 125篇 |
2003年 | 94篇 |
2002年 | 100篇 |
2001年 | 54篇 |
2000年 | 64篇 |
1999年 | 48篇 |
1998年 | 36篇 |
1997年 | 37篇 |
1996年 | 40篇 |
1995年 | 28篇 |
1994年 | 29篇 |
1993年 | 20篇 |
1992年 | 20篇 |
1991年 | 10篇 |
1990年 | 24篇 |
1989年 | 17篇 |
1988年 | 13篇 |
1987年 | 14篇 |
1986年 | 19篇 |
1985年 | 19篇 |
1984年 | 11篇 |
1983年 | 9篇 |
1982年 | 13篇 |
1981年 | 19篇 |
1980年 | 21篇 |
1979年 | 12篇 |
1978年 | 12篇 |
1977年 | 10篇 |
1976年 | 12篇 |
1975年 | 11篇 |
1974年 | 13篇 |
排序方式: 共有4015条查询结果,搜索用时 15 毫秒
61.
Advances in Data Analysis and Classification - Online social network is a major media for many types of information communication. Although the primary purpose of social networks is to connect... 相似文献
62.
It is proved that the even-order equationy
(2n)
+p(t)y=0 is (n,n) oscillatory at if
相似文献
63.
64.
65.
For any -complexes and , we show that . We use this fact to compute generalized evaluation subgroups of generalized tori relative to a sphere.
66.
67.
Nguyen Quang Do Thong 《K-Theory》1993,7(5):429-441
The well-known formula of Riemann-Hurwitz gives the change of genuses in ann-fold covering of compact connected Riemann surfaces. In Iwasawa theory, there existp-adic analogues which give the change of certain ±-invariants in ap-extension ofCM number fields. Using functorial and arithmetical properties ofK
3, we extend such Riemann-Hurwitzp-adic formulas to non-CM fields, assuming some restrictive hypotheses on the capitulation ofK
2. 相似文献
68.
69.
A thermodynamic approach is developed in this paper to describe the behavior of a subcritical fluid in the neighborhood of vapor-liquid interface and close to a graphite surface. The fluid is modeled as a system of parallel molecular layers. The Helmholtz free energy of the fluid is expressed as the sum of the intrinsic Helmholtz free energies of separate layers and the potential energy of their mutual interactions calculated by the 10-4 potential. This Helmholtz free energy is described by an equation of state (such as the Bender or Peng-Robinson equation), which allows us a convenient means to obtain the intrinsic Helmholtz free energy of each molecular layer as a function of its two-dimensional density. All molecular layers of the bulk fluid are in mechanical equilibrium corresponding to the minimum of the total potential energy. In the case of adsorption the external potential exerted by the graphite layers is added to the free energy. The state of the interface zone between the liquid and the vapor phases or the state of the adsorbed phase is determined by the minimum of the grand potential. In the case of phase equilibrium the approach leads to the distribution of density and pressure over the transition zone. The interrelation between the collision diameter and the potential well depth was determined by the surface tension. It was shown that the distance between neighboring molecular layers substantially changes in the vapor-liquid transition zone and in the adsorbed phase with loading. The approach is considered in this paper for the case of adsorption of argon and nitrogen on carbon black. In both cases an excellent agreement with the experimental data was achieved without additional assumptions and fitting parameters, except for the fluid-solid potential well depth. The approach has far-reaching consequences and can be readily extended to the model of adsorption in slit pores of carbonaceous materials and to the analysis of multicomponent adsorption systems. 相似文献
70.
|