全文获取类型
收费全文 | 4316篇 |
免费 | 694篇 |
国内免费 | 407篇 |
专业分类
化学 | 561篇 |
晶体学 | 26篇 |
力学 | 962篇 |
综合类 | 41篇 |
数学 | 867篇 |
物理学 | 2960篇 |
出版年
2024年 | 6篇 |
2023年 | 53篇 |
2022年 | 67篇 |
2021年 | 78篇 |
2020年 | 115篇 |
2019年 | 96篇 |
2018年 | 124篇 |
2017年 | 135篇 |
2016年 | 136篇 |
2015年 | 136篇 |
2014年 | 223篇 |
2013年 | 315篇 |
2012年 | 280篇 |
2011年 | 338篇 |
2010年 | 273篇 |
2009年 | 262篇 |
2008年 | 267篇 |
2007年 | 261篇 |
2006年 | 254篇 |
2005年 | 227篇 |
2004年 | 203篇 |
2003年 | 205篇 |
2002年 | 183篇 |
2001年 | 151篇 |
2000年 | 143篇 |
1999年 | 131篇 |
1998年 | 88篇 |
1997年 | 88篇 |
1996年 | 76篇 |
1995年 | 86篇 |
1994年 | 70篇 |
1993年 | 54篇 |
1992年 | 28篇 |
1991年 | 35篇 |
1990年 | 27篇 |
1989年 | 32篇 |
1988年 | 26篇 |
1987年 | 31篇 |
1986年 | 17篇 |
1985年 | 12篇 |
1984年 | 14篇 |
1983年 | 4篇 |
1982年 | 16篇 |
1981年 | 12篇 |
1980年 | 6篇 |
1979年 | 9篇 |
1978年 | 7篇 |
1976年 | 6篇 |
1975年 | 3篇 |
1973年 | 2篇 |
排序方式: 共有5417条查询结果,搜索用时 31 毫秒
1.
X-ray emission for Ar11+ ions impacting on various targets in the collisions near the Bohr velocity 下载免费PDF全文
Xian-Ming Zhou 《中国物理 B》2021,30(8):83201-083201
X-ray emission from the collisions of 3 MeV Ar11+ ions with V, Fe, Co, Ni, Cu, and Zn is investigated. Both the x-rays of the target atom and projectile are observed simultaneously. The x-ray yield is extracted from the original count. The inner-shell ionization cross section is estimated by the binary encounter approximation model and compared with the experimental result. The remarkable result is that the Ar K-shell x-ray yield is diminished with the target atomic number increasing, which is completely opposite to the theoretical calculation. That is interpreted by the competitive consumption of the energy loss for the ionization of inner-shell electrons between the projectile and target atom. 相似文献
2.
This paper is concerned with the Cauchy problem on the Boltzmann equation without angular cutoff assumption for hard potential in the whole space. When the initial data is a small perturbation of a global Maxwellian, the global existence of solution to this problem is proved in unweighted Sobolev spaces with . But if we want to obtain the optimal temporal decay estimates, we need to add the velocity weight function, in this case the global existence and the optimal temporal decay estimate of the Boltzmann equation are all established. Meanwhile, we further gain a more accurate energy estimate, which can guarantee the validity of the assumption in Chen et al. (0000). 相似文献
3.
4.
5.
Study on divertor plasma behavior through sweeping strike point in new lower divertor on EAST 下载免费PDF全文
Yu-Qiang Tao 《中国物理 B》2022,31(6):65204-065204
A series of L-mode discharges have been conducted in the new ‘corner slot’ divertor on the Experimental Advanced Superconducting Tokamak (EAST) to study the divertor plasma behavior through sweeping strike point. The plasma control system controls the strike point sweeping from the horizontal target to the vertical target through poloidal field coils, with keeping the main plasma stability. The surface temperature of the divertor target cools down as the strike point moves away, indicating that sweeping strike point mitigates the heat load. To avoid the negative effect of probe tip damage, a method based on sweeping strike point is used to get the normalized profile and study the decay length of particle and heat flux on the divertor target λjs, λq. In the discharges with high radio-frequency (RF) heating power, electron temperature Te is lower and λjs is larger when the strike point locates on the horizontal target compared to the vertical target, probably due to the corner effect. In the Ohmic discharges, λjs, λq are much larger compared to the discharges with high RF heating power, which may be attributed to lower edge Te. 相似文献
6.
A. Bande 《Molecular physics》2019,117(15-16):2014-2028
ABSTRACTRecently, highly accurate multi-configuration time-dependent Hartree electron dynamics calculations demonstrated the efficient long-range energy transfer inter-Coulombic decay (ICD) process to happen in charged semiconductor quantum dot (QD) pairs. ICD is initiated by intraband photoexcitation of one of the QDs and leads to electron emission from the other within a duration of about 150 ps. On the same time scale electronically excited states are reported to relax due to the coupling of electrons to acoustic phonons. Likewise, phonons promote ionisation. Here, the QDs' acoustic breathing mode is implemented in a frozen-phonon approach. A detailed comparison of the phonon effects on electron relaxation and emission as well as on the full ICD process is presented, which supports the previous empirical finding of ICD being the dominant decay channel in paired QDs. In addition the relative importance of phonon–phonon, phonon–electron and electron–electron interaction is analysed. 相似文献
7.
In this paper, we consider a viscoelastic wave equation of variable coefficients in the presence of past history with nonlinear damping and delay in the internal feedback and dynamic boundary conditions. Under suitable assumptions, we establish an explicit and general decay rate result without imposing restrictive assumption on the behavior of the relaxation function at infinity by Riemannian geometry method and Lyapunov functional method. 相似文献
8.
《Mathematical Methods in the Applied Sciences》2018,41(9):3294-3306
In this article, we consider the asymptotic behavior of the classical solution to the 3‐dimensional Vlasov‐Poisson plasma interacting repulsively with N point charges. The large time behavior in terms of diameters of its velocity‐spatial supports is improved to O(t2/3+ϵ) for any ϵ>0. 相似文献
9.
This paper deals with the initial boundary value problem for strongly damped semilinear wave equations with logarithmic nonlinearity in a bounded domain . We discuss the existence, uniqueness and polynomial or exponential energy decay estimates of global weak solutions under some appropriate conditions. Moreover, we derive the finite time blow up results of weak solutions, and give the lower and upper bounds for blow-up time by the combination of the concavity method, perturbation energy method and differential–integral inequality technique. 相似文献
10.