全文获取类型
收费全文 | 7462篇 |
免费 | 301篇 |
国内免费 | 32篇 |
专业分类
化学 | 4586篇 |
晶体学 | 30篇 |
力学 | 210篇 |
数学 | 1379篇 |
物理学 | 1590篇 |
出版年
2023年 | 59篇 |
2022年 | 58篇 |
2021年 | 189篇 |
2020年 | 191篇 |
2019年 | 172篇 |
2018年 | 138篇 |
2017年 | 125篇 |
2016年 | 273篇 |
2015年 | 268篇 |
2014年 | 259篇 |
2013年 | 368篇 |
2012年 | 486篇 |
2011年 | 547篇 |
2010年 | 308篇 |
2009年 | 286篇 |
2008年 | 436篇 |
2007年 | 407篇 |
2006年 | 369篇 |
2005年 | 334篇 |
2004年 | 275篇 |
2003年 | 211篇 |
2002年 | 222篇 |
2001年 | 120篇 |
2000年 | 84篇 |
1999年 | 107篇 |
1998年 | 75篇 |
1997年 | 96篇 |
1996年 | 65篇 |
1995年 | 69篇 |
1994年 | 85篇 |
1993年 | 64篇 |
1992年 | 58篇 |
1991年 | 51篇 |
1990年 | 47篇 |
1989年 | 40篇 |
1988年 | 50篇 |
1987年 | 60篇 |
1986年 | 47篇 |
1985年 | 59篇 |
1984年 | 54篇 |
1983年 | 34篇 |
1982年 | 47篇 |
1981年 | 39篇 |
1980年 | 39篇 |
1979年 | 42篇 |
1978年 | 40篇 |
1977年 | 28篇 |
1976年 | 43篇 |
1975年 | 26篇 |
1973年 | 30篇 |
排序方式: 共有7795条查询结果,搜索用时 31 毫秒
131.
Roland Huber 《Geometriae Dedicata》1995,58(3):291-311
We show some topological properties of semianalytic subsets of rigid analytic varieties: curve selection lemma, the closure
of a semianalytic subsetS is semianalytic,
for every quasi-compact morphismf. As an application we show that a morphismf: X Y of rigid analytic varieties is open at a pointx X if and only if SpecO
X,x SpecO
Y,f(x) is surjective. 相似文献
132.
133.
134.
We consider the statistical properties of solutions of Burgers' equation in the limit of vanishing viscosity,
, with Gaussian whitenoise initial data. This system was originally proposed by Burgers[1] as a crude model of hydrodynamic turbulence, and more recently by Zel'dovichet al..[12] to describe the evolution of gravitational matter at large spatio-temporal scales, with shocks playing the role of mass clusters. We present here a rigorous proof of the scaling relationP(s)s
1/2,s1 whereP(s) is the cumulative probability distribution of shock strengths. We also show that the set of spatial locations of shocks is discrete, i.e. has no accumulation points; and establish an upper bound on the tails of the shock-strength distribution, namely 1–P(s)exp{–Cs
3} fors1. Our method draws on a remarkable connection existing between the structure of Burgers turbulence and classical probabilistic work on the convex envelope of Brownian motion and related diffusion processes.Inadvertently the sequel to this article, Statistical Properties of Shocks in Burgers Turbulence, II. Tail Probabilities for Velocities, Shock-Strengths and Rarefaction Intervals has already appeared in an earlier issue of Commun. Math. Phys. (Commun. Math. Phys.169, 45–59 (1995). 相似文献
135.
136.
The setting up and updating of a Mössbauer laboratory imply the acquisition and assembling of different units. Guidelines concerning either the construction or the acquisition of the various parts which compose a Mössbauer spectrometer are given in this paper. 相似文献
137.
The57Fe Mössbauer spectrum recorded from the material of composition Fe0.25NbTiP3O12 shows the presence of Fe2+ in a distribution of approximately octahedral type I sites within the channels of the NbTiP3O12 structure. A comparison of the results with those recorded from the material Fe0.33NbTiP3O12 demonstrates the existence of an upper limit to the occupation by the Fe2+ species of the type I sites. Lattice parameter measurements and57Fe Mössbauer spectroscopy show that treatment of Fe0.25NbTiP3O12 in air induces the migration of the incorporated iron from the channels to form macroscopic -Fe2O3. 相似文献
138.
We find that the CP-violating asymmetry
at the one-loop order within the minimal supersymmetric extension of the standard model is of the order of few percent for maximal CP violation. It could be measured by considering the rate difference in the one-lepton events. 相似文献
Full-size image
139.
Groundstate absorption, fluorescence, excited-state absorption, and stimulated emission of Pr:YA1O3 were measured in dependence on the polarization. The results reflect the anisotropy of the host lattice. Especially the polarized spectra of the stimulated emission fit very well with the laser data of this material. Seven cw laser transitions in the visible spectral range obtained so far in Pr:YA1O3 with argon-ion laser pumping were identified in the spectra of the stimulated emission. In addition, two infrared cw laser transitions were realized. The best results were achieved for the3
P
03
F
4 laser transition at 746.9 nm with a maximum slope efficiency of 24.6%, a maximum output power of 49.6 mW, and a laser threshold of 25 mW. 相似文献
140.
T. Sandrock T. Danger E. Heumann G. Huber B. H. T. Chai 《Applied physics. B, Lasers and optics》1994,58(2):149-151
We report, to our knowledge for the first time, Continuous Wave (CW) laser emission at room temperature of Pr:LiYF4 (Pr.YLF) at six wavelengths: 522, 545, 607, 639.5, 720 and 907.4 nm. The pump source was an argon-ion laser tuned to a wavelength of = 457.9 nm. The maximum output powers at 522 nm (3Pi 3H5) and 639.5 nm (3P0 3F2) were 144 and 266 mW, respectively. We also observed CW laser action of Pr:GdLiF4 (Pr: GLF) at = 639 nm and of Pr:KYF4 (Pr: KYF) at = 642.5 nm. 相似文献