全文获取类型
收费全文 | 17278篇 |
免费 | 739篇 |
国内免费 | 7篇 |
专业分类
化学 | 9742篇 |
晶体学 | 46篇 |
力学 | 375篇 |
数学 | 2451篇 |
物理学 | 5410篇 |
出版年
2023年 | 137篇 |
2021年 | 154篇 |
2020年 | 249篇 |
2019年 | 155篇 |
2018年 | 205篇 |
2017年 | 192篇 |
2016年 | 460篇 |
2015年 | 443篇 |
2014年 | 438篇 |
2013年 | 788篇 |
2012年 | 795篇 |
2011年 | 968篇 |
2010年 | 434篇 |
2009年 | 388篇 |
2008年 | 821篇 |
2007年 | 802篇 |
2006年 | 784篇 |
2005年 | 653篇 |
2004年 | 512篇 |
2003年 | 475篇 |
2002年 | 439篇 |
2001年 | 421篇 |
2000年 | 328篇 |
1999年 | 259篇 |
1998年 | 212篇 |
1997年 | 218篇 |
1996年 | 226篇 |
1995年 | 207篇 |
1994年 | 198篇 |
1993年 | 228篇 |
1992年 | 230篇 |
1991年 | 181篇 |
1990年 | 152篇 |
1989年 | 146篇 |
1988年 | 130篇 |
1987年 | 154篇 |
1986年 | 161篇 |
1985年 | 180篇 |
1984年 | 214篇 |
1983年 | 193篇 |
1982年 | 190篇 |
1981年 | 206篇 |
1980年 | 178篇 |
1979年 | 170篇 |
1978年 | 184篇 |
1977年 | 177篇 |
1976年 | 153篇 |
1975年 | 140篇 |
1974年 | 146篇 |
1973年 | 134篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
D. Kaptás T. Kemény J. Balogh L. F. Kiss L. Gránásy I. Vincze 《Hyperfine Interactions》1994,94(1):1861-1865
The temperature dependence of the iron hyperfine field distribution is reported in melt-quenched amorphous Fe-Zr alloys. The most remarkable feature is the compositinal change in the shape of the average hyperfine field versus temperature curves. The unusual increase in the average hyperfine field below about 85 K is a characteristic feature of the RSG systems; however, no anomaly is observed in the width of the hyperfine field distribution as a function of temperature. The results cannot be properly explained in the framework of the existing spin glass models. 相似文献
92.
J. Walz S. B. Ross C. Zimmermann L. Ricci M. Prevedelli T. W. Hänsch 《Hyperfine Interactions》1996,100(1):133-144
Experiments with electrons and ions in a combined trap are reported. The unique capability to confine particles with opposite charge and very different mass simultaneously in the same spatial region makes the combined trap a promising device for future synthesis of antihydrogen. 相似文献
93.
We introduce triplet spaces for symmetric relations with defect index (1, 1) in a Pontryagin space. Representations of Pontryagin spaces by spaces of vector-valued analytic functions are investigated. These concepts are used to study 2×2-matrix valued analytic functions which satisfy a certain kernel condition. 相似文献
94.
95.
T.R. Saitoh N. Hashimoto G. Sletten R.A. Bark S. Törmänen M. Bergström K. Furuno K. Furutaka G.B. Hagemann T. Hayakawa T. Komatsubara A. Maj S. Mitarai M. Oshima J. Sampson T. Shizuma P.G. Varmette 《The European Physical Journal A - Hadrons and Nuclei》1998,3(3):197-199
High-spin states in 181Ta have been studied via the 176Yb(11B,α2n) reaction at 52 MeV using the PEX array and at 57 MeV using the NORDBALL array, with α-particle detection. The previously
known, Kπ=(7/2)+ ground state band and Kπ=(9/2)− band have been extended to spins (29/2)+ and (31/2)−, respectively. Two new one-quasiparticle bands, the Kπ=(5/2)+ band built on the known (5/2)+ isomer and a Kπ=((1/2)−) band have been observed. Two other rotational bands with three-quasiparticle structure, Kπ=(15/2)− and ((19/2)+ with π(7/2)[404]ν2(1/2)[510](9/2)[624] and π(9/2)[514]ν2(1/2)[510](9/2)[624] configurations, respectively, have been newly observed. The half-life of the Kπ=((19/2)+) bandhead which decays to the head of the (15/2)− band has been measured to be 140(36) ns. However, transitions from the ((19/2)+) state to the (15/2)− band have not been observed.
Received: 26 August 1998 相似文献
96.
A. Bachem W. Hochstättler B. Steckemetz A. Volmer 《Computational Optimization and Applications》1996,6(3):213-225
We report on computational experience with an implementation of three algorithms for the general economic equilibrium problem. As a result we get that the projection algorithm for variational inequalities increases the size of solvable models by a factor of 5–10 in comparison with the classical homotopy method. As a third approach we implemented a simulated annealing heuristic which might be suitable to estimate equilibria for very large models.Supported by the German Research Association (Deutsche Forschungsgemeinschaft, SFB 303). 相似文献
97.
A striking size dependence of the mean-square displacement of diffusing particles in the two-dimensional lattice gas of hard squares has been observed by Monte Carlo simulation. It is shown that the size effect is due to the formation of a stable cage structure in small lattices when the particle concentration is high. The formation of cages is governed by a new type of percolation problem related to bootstrap percolation. 相似文献
98.
Márton Balázs Firas Rassoul-Agha Timo Seppäläinen 《Communications in Mathematical Physics》2006,266(2):499-545
We study space-time fluctuations around a characteristic line for a one-dimensional interacting system known as the random average process. The state of this system is a real-valued function on the integers. New values of the function are created by averaging previous values with random weights. The fluctuations analyzed occur on the scale n 1/4, where n is the ratio of macroscopic and microscopic scales in the system. The limits of the fluctuations are described by a family of Gaussian processes. In cases of known product-form invariant distributions, this limit is a two-parameter process whose time marginals are fractional Brownian motions with Hurst parameter 1/4. Along the way we study the limits of quenched mean processes for a random walk in a space-time random environment. These limits also happen at scale n 1/4 and are described by certain Gaussian processes that we identify. In particular, when we look at a backward quenched mean process, the limit process is the solution of a stochastic heat equation. 相似文献
99.
Stefanie M. Walz Thomas E. Malner Ulrich Mueller Rolf Muelhaupt 《Journal of Polymer Science.Polymer Physics》2003,41(4):360-367
We explored phase separation and self‐assembly of perfluoroalkyl segments at the surface of polymer films obtained from latices of semifluorinated acrylate copolymers and the corresponding latex blends of nonfluorinated and semifluorinated polyacrylates. With laser‐induced secondary mass spectrometry the fluorine distribution was measured after annealing above the minimum film‐forming temperature of the polymers up to a depth of several micrometers. Depth profiles of a semifluorinated acrylate homopolymer and latex blends thereof with fluorine‐free alkylacrylates with 25, 50, and 75 mol % semifluorinated acrylate as well as a copolymer comprised of alkyl acrylate and semifluorinated acrylate (50/50 mol %) were investigated. In the case of latex blends containing both semifluorinated polyacrylates and fluorine‐free or low‐fluorine polymers, self‐assembly accounted for enrichment of the perfluoroalkyl segments at the surface. Coatings exhibiting low surface energy and having a substantially reduced total fluorine content were obtained. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 360–367, 2003 相似文献
100.