全文获取类型
收费全文 | 1489篇 |
免费 | 25篇 |
专业分类
化学 | 785篇 |
晶体学 | 6篇 |
力学 | 85篇 |
数学 | 242篇 |
物理学 | 396篇 |
出版年
2018年 | 14篇 |
2016年 | 21篇 |
2015年 | 22篇 |
2014年 | 14篇 |
2013年 | 118篇 |
2012年 | 18篇 |
2011年 | 25篇 |
2010年 | 13篇 |
2009年 | 14篇 |
2006年 | 26篇 |
2002年 | 30篇 |
2001年 | 17篇 |
2000年 | 23篇 |
1999年 | 18篇 |
1998年 | 28篇 |
1997年 | 24篇 |
1996年 | 30篇 |
1995年 | 20篇 |
1994年 | 21篇 |
1993年 | 16篇 |
1992年 | 22篇 |
1991年 | 26篇 |
1990年 | 20篇 |
1989年 | 25篇 |
1988年 | 33篇 |
1987年 | 24篇 |
1986年 | 21篇 |
1985年 | 26篇 |
1984年 | 30篇 |
1983年 | 29篇 |
1982年 | 28篇 |
1981年 | 25篇 |
1980年 | 19篇 |
1979年 | 32篇 |
1978年 | 31篇 |
1977年 | 33篇 |
1976年 | 48篇 |
1975年 | 42篇 |
1974年 | 48篇 |
1973年 | 58篇 |
1972年 | 38篇 |
1971年 | 39篇 |
1970年 | 29篇 |
1969年 | 24篇 |
1968年 | 25篇 |
1967年 | 20篇 |
1966年 | 13篇 |
1964年 | 13篇 |
1960年 | 16篇 |
1959年 | 17篇 |
排序方式: 共有1514条查询结果,搜索用时 15 毫秒
81.
We justify the averaging method for systems with delay described by both slow and fast variables. The results obtained are applied to the analysis of one problem in control theory. 相似文献
82.
Some asymptotic results are proved for the distribution of the maximum of a centered Gaussian random field with unit variance on a compact subset S of
N
. They are obtained by a Rice method and the evaluation of some moments of the number of local maxima of the Gaussian field above an high level inside S and on the border S. Depending on the geometry of the border we give up to N+1 terms of the expansion sometimes with exponentially small remainder. Application to waves maximum is shown. 相似文献
83.
N. B. Éshkobilov 《Journal of Applied Spectroscopy》2002,69(3):477-479
The main series of a silver atom with n = 5–70 are investigated. Perturbations of the np
2
P
1/2,3/2 states with n = 10 and 17 caused by interaction with the selfionization 4d5s5p
4
P
1/2,3/2 states are detected. Energies of the selfionization states are determined. 相似文献
84.
A three degree-of-freedom model is proposed to predict the biodynamic responses of the seated human body of different masses. A baseline model is initially derived to satisfy both the mean apparent mass and seat-to-head transmissibility responses proposed in ISO/DIS 5982:2000 applicable for mean body mass of 75 kg. The validity of the resultant generic mass dependent model is verified by comparing the apparent mass and driving-point mechanical impedance responses computed for total body masses of 55, 75 and 90 kg with the range of idealized values proposed for body masses within the 49-93 kg range. Considering the lack of data that could be found to define the apparent mass/mechanical impedance of subjects with different body masses when applying the experimental conditions defined in ISO/DIS 5982:2000, an attempt is made to adapt the parameters of the base model to fit the measured apparent mass data applicable to groups of automobile occupants within different mass ranges. This is achieved through constrained parametric optimization which consists of minimizing the sum of squared errors between the computed response and the mean apparent mass data measured for automobile occupants within four mass groups: less than 60 kg, 60·5-70·5 kg, 70·5-80 kg and above 80 kg. The results show a reasonably good agreement between the model responses and the measured apparent mass data, particularly at frequencies below 10 Hz. The results suggest that the proposed mass dependent model can effectively predict the apparent mass responses of automobile occupants over a wide range of body masses and for two different postures: passenger (hands-in-lap) and driver (hands-on-steering wheel) postures. 相似文献
85.
V. A. Zamureenko N. A. Klyuev L. B. Dmitriev I. I. Grandberg G. A. Ésvandzhiya 《Chemistry of Natural Compounds》1984,20(6):681-683
The composition of the terpenoid and sesquiterpene hydrocarbon fraction ofSalvia garedzhii has been studied by chromato-mass spectrometry. A total of 19 compounds have been identified and a provisional assignment of another 6 components has been made. 相似文献
86.
87.
88.
A strongly polynomial minimum cost circulation algorithm 总被引:2,自引:0,他引:2
Éva Tardos 《Combinatorica》1985,5(3):247-255
A new algorithm is presented for the minimum cost circulation problem. The algorithm is strongly polynomial, that is, the
number of arithmetic operations is polynomial in the number of nodes, and is independent of both costs and capacities. 相似文献
89.
90.