全文获取类型
收费全文 | 23765篇 |
免费 | 5122篇 |
国内免费 | 7468篇 |
专业分类
化学 | 5538篇 |
晶体学 | 223篇 |
力学 | 1708篇 |
综合类 | 1155篇 |
数学 | 16772篇 |
物理学 | 10959篇 |
出版年
2024年 | 186篇 |
2023年 | 559篇 |
2022年 | 762篇 |
2021年 | 730篇 |
2020年 | 568篇 |
2019年 | 617篇 |
2018年 | 453篇 |
2017年 | 776篇 |
2016年 | 847篇 |
2015年 | 1026篇 |
2014年 | 1791篇 |
2013年 | 1423篇 |
2012年 | 1857篇 |
2011年 | 1991篇 |
2010年 | 1872篇 |
2009年 | 1902篇 |
2008年 | 2047篇 |
2007年 | 1678篇 |
2006年 | 1599篇 |
2005年 | 1739篇 |
2004年 | 1466篇 |
2003年 | 1357篇 |
2002年 | 1055篇 |
2001年 | 1139篇 |
2000年 | 906篇 |
1999年 | 755篇 |
1998年 | 674篇 |
1997年 | 619篇 |
1996年 | 612篇 |
1995年 | 598篇 |
1994年 | 599篇 |
1993年 | 445篇 |
1992年 | 410篇 |
1991年 | 386篇 |
1990年 | 385篇 |
1989年 | 305篇 |
1988年 | 69篇 |
1987年 | 50篇 |
1986年 | 25篇 |
1985年 | 27篇 |
1984年 | 18篇 |
1983年 | 7篇 |
1982年 | 6篇 |
1980年 | 5篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1963年 | 1篇 |
1959年 | 6篇 |
1951年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
71.
72.
Quantum Inequality for Negative Energy Density States of Massive Dirac Field in Four-Dimensional Spacetime
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Negative energy density and the quantum inequality are examined for the Dirac field. A proof is given of the quantum inequality for negative energy densities in the massive Dirac field produced by the superposition of two single particle electron states. 相似文献
73.
ZHANG Yongqian 《数学年刊B辑(英文版)》2005,26(3):379-392
This paper studies the asymptotic behaviour of steady supersonic flow past a piece-wise smooth corner or bend. Under the hypothese that both vertex angle and the total variation of tangent along the boundary are small, it is shown that the solution can be obtained by a modified Glimm scheme, and that the asymptotic behaviour of the solution is determined by the velocity of incoming flow and the limit of the tangent of the boundary at infinity. 相似文献
74.
The authors study the singular integrals under the Hormander condition and the measure not satisfying the doubling condition. At first, if the corresponding singular integral is bounded from L2 to itself, it is proved that the maximal singular integral is bounded from L∞to RBMO except that it is infinite μ-a.e. on Rd. A sufficient condition and a necessary condition such that the maximal singular integral is bounded from L2 to itself are also obtained. There is a small gap between the two conditions. 相似文献
75.
The Iyengar Type Inequalities with Exact Estimations and the Chebyshev Central Algorithms of Integrals 总被引:3,自引:0,他引:3
Xing Hua WANG Shi Jun YANG 《数学学报(英文版)》2005,21(6):1361-1376
In this paper, both low order and high order extensions of the Iyengar type inequality are obtained. Such extensions are the best possible in the same sense as that of the Iyengar inequality. hzrthermore, the Chebyshev central algorithms of integrals for some function classes and some related problems are also considered and investigated. 相似文献
76.
The Δ-scaling method has been applied to ultra-relativistic p p,C C and Pb Pb collision data simulated using a high-energy Monte Carlo package,LUCIAE 3.0.The Δ-scaling is found to be valid for some physical variables,such as charged particle multiplicity,strange particle multiplicity and number of binary nucleon-nucleon-nucleon collisions from these simulated nucleus-nucleus collisions over an extended energy ranging from E1ab=20 to 200A GeV.In addition we derive the information entropy from the multiplicity distribution as a function of beam energy for these collisions. 相似文献
77.
78.
As in other parts of physics, we advocate the interaction approach: experiments ←→ (… are influenced and their importance is determined by … and vice versa) phenomenology ←→ low-energy effective (field) theory ←→ microscopic theory to probe the microscopic origin of gravity, Using the X-g phenomenological framework, we discuss the tests of equivalence principles. The only experimentally unconstrained degree of freedom is the axion freedom. It has effects on the long-range astrophysical/cosmological propagation of electromagnetic waves and can be tested/measured using the future generation of polarization measurement of cosmic background radiation.The verification or refutal of this axionic effect will be a crucial step for constructing an effective theory and probing the microscopic origin of gravity. The interaction of spin with gravity is another important clue for probing the microscopic origin of gravity. The interplay of experiments, phenomenology and effective theory are expounded. An ideal way to reveal the microscopic origin of gravity is to measure the gyrogravitational ratio of particles, Three potential experimental methods are considered. 相似文献
79.
通过重离子核反应与在束γ谱的实验技术, 对A=130缺中子核区的双奇核136La的高自旋态进行了研究, 所用核反应为130Te(11B,5n). 实验结果扩展了136La的能级纲图, 包括3个集体转动带, 最高自旋态达20h. 对于\uppi h_{11/2}\otimes \upnu h_{11/2}$~带, 观测到了旋称反转与集体回弯现象. 通过系统学比较, 对旋称反转特性进行了讨论. 由推转壳模型的计算指出, 此集体回弯是由一对中子的角动量顺排引起的. 另外两个集体带为具有~$\gamma\approx -60^\circ$~的扁椭形变带, 其可能的组态为: $\uppi h_{11/2}\otimes \upnu g_{7/2}h_{11/2}^2$~与~$\uppi g_{7/2}\otimes\upnu g_{7/2}^2 d_{5/2} h_{11/2}^2$. 相似文献
80.