全文获取类型
收费全文 | 135696篇 |
免费 | 2192篇 |
国内免费 | 538篇 |
专业分类
化学 | 60362篇 |
晶体学 | 1133篇 |
力学 | 7602篇 |
综合类 | 5篇 |
数学 | 41951篇 |
物理学 | 27373篇 |
出版年
2023年 | 387篇 |
2022年 | 495篇 |
2021年 | 825篇 |
2020年 | 889篇 |
2019年 | 915篇 |
2018年 | 11130篇 |
2017年 | 10904篇 |
2016年 | 7856篇 |
2015年 | 2488篇 |
2014年 | 2019篇 |
2013年 | 4064篇 |
2012年 | 7229篇 |
2011年 | 13679篇 |
2010年 | 7813篇 |
2009年 | 7933篇 |
2008年 | 9531篇 |
2007年 | 11426篇 |
2006年 | 2955篇 |
2005年 | 3884篇 |
2004年 | 3709篇 |
2003年 | 3816篇 |
2002年 | 2633篇 |
2001年 | 1531篇 |
2000年 | 1519篇 |
1999年 | 1040篇 |
1998年 | 887篇 |
1997年 | 787篇 |
1996年 | 1004篇 |
1995年 | 697篇 |
1994年 | 740篇 |
1993年 | 710篇 |
1992年 | 677篇 |
1991年 | 595篇 |
1990年 | 621篇 |
1989年 | 527篇 |
1988年 | 513篇 |
1987年 | 498篇 |
1986年 | 476篇 |
1985年 | 600篇 |
1984年 | 574篇 |
1983年 | 443篇 |
1982年 | 451篇 |
1981年 | 459篇 |
1980年 | 414篇 |
1979年 | 383篇 |
1978年 | 350篇 |
1977年 | 335篇 |
1976年 | 349篇 |
1974年 | 298篇 |
1973年 | 332篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Berry Frank J. Ren Xiaolin Gancedo J. Ramón Marco José F. 《Hyperfine Interactions》2004,156(1-4):335-340
Hyperfine Interactions - Perovskite-related phases of the type LaFe1?x Co x O3 (x=0 and 0.5) have been synthesised by milling techniques. The materials are of smaller particle size and more... 相似文献
992.
Hua Ning LIU Wen Peng ZHANG 《数学学报(英文版)》2007,23(5):915-924
The main purpose of this paper is to use the generalized Bernoulli numbers, Gauss sums and the mean value theorems of Dirichlet L-functions between a quadratic residue and its inverse modulo p value formula. to study the asymptotic property of the difference (a prime), and to give an interesting hybrid mean 相似文献
993.
Aurelien Drezet 《Pramana》2007,68(3):389-396
In a paper by Home and Agarwal [1], it is claimed that quantum nonlocality can be revealed in a simple interferometry experiment
using only single particles. A critical analysis of the concept of hidden variable used by the authors of [1] shows that the
reasoning is not correct.
相似文献
994.
A.V. Andreev B. Janoušová V. Sechovský Y. Homma Y. Shiokawa 《Czechoslovak Journal of Physics》2002,52(2):275-278
We present the first single-crystal study of Fe and Ni doped U(Co1-x
T
x
)Al compounds in comparison to the parent compound, the itinerant 5f-electron metamagnet UCoAl. Magnetization and specific-heat data measured in the temperature range of (1.8-300) K and in fields up to 10 T are analyzed and discussed. Both compounds exhibit a strong uniaxial anisotropy with the dominating magnetic response along the c-axis of the hexagonal ZrNiAl-type structure. Ni substitution yields an increase of the critical field for metamagnetism; UCo0.95Fe0.05Al is ferromagnetic below 30 K. Temperature evolution of the entropy change between 0 and 10 T points to involvement of magnetic correlations or spin fluctuations in the paramagnetic compounds UCoAl and UCo0.95Ni0.05Al. 相似文献
995.
996.
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
997.
A quick sample preparation method was used for the determination of sulphur and trace metals in oil and oily products by the ICP with a minitorch. Stable aqueous emulsions of oils and oil products were made by using two kinds of emulsifiers (one with low sulphur content, the other sulfonated). Aqueous standard solutions can be used for the preparation of calibration solutions. The contents of S, Al, Cr, Cu, Fe, Mg, Ni and Pb in aqueous emulsions were determined and the results were in good agreement with the composition of oil standard solutions used for control analysis procedure. 相似文献
998.
We study extension of operators T: E→ L0([0, 1]), where E is an F–function space and L0([0, 1]) the space of measurable functions with the topology of convergence in measure, to domains larger than E, and we study the properties of such domains. The main tool is the integration of scalar functions with respect to stochastic
measures and the corresponding spaces of integrable functions.
Partially supported by D.G.I. #MTM2006-13000-C03-01 (Spain). 相似文献
999.
1000.
We reported controllable synthesis of ZnS nanocrystal-polymer transparent hybrids by using polymethylmethacrylate (PMMA) as
a polymer matrix. In a typical run, the appropriate amounts of zinc chloride (ZnCl2) and sodium sulfide (Na2S) in the presence of 2-mercaptoethanol (ME) as the organic ligand were well dispersed in H2O/dimethylformamide solution without any aggregation. In addition, the Mn-doped ZnS nanocrystals (NCs) were synthesized with
similar method. Then, ZnS-PMMA hybrids were obtained via free radical polymerization in situ by using ZnS NCs functionalized
with methacryloxypropyltrimethoxysilane (MPS). FT-IR characterization indicates the formation of robust bonding between ZnS
NCs and the organic ligand. The TEM images show that ZnS NCs are well dispersed in PMMA matrix, and particle size of as-prepared
ZnS NCs is about 2.6 nm, in agreement with the computing results of Brus’s model and Debye–Scherrer formula. The photoluminescence
measurements present that ZnS NCs, Mn-doped ZnS NCs, and ZnS/PMMA hybrid show good optical properties. 相似文献