全文获取类型
收费全文 | 17978篇 |
免费 | 3225篇 |
国内免费 | 3238篇 |
专业分类
化学 | 13187篇 |
晶体学 | 300篇 |
力学 | 1049篇 |
综合类 | 309篇 |
数学 | 2320篇 |
物理学 | 7276篇 |
出版年
2024年 | 43篇 |
2023年 | 339篇 |
2022年 | 651篇 |
2021年 | 705篇 |
2020年 | 724篇 |
2019年 | 805篇 |
2018年 | 641篇 |
2017年 | 666篇 |
2016年 | 858篇 |
2015年 | 921篇 |
2014年 | 1121篇 |
2013年 | 1364篇 |
2012年 | 1601篇 |
2011年 | 1614篇 |
2010年 | 1172篇 |
2009年 | 1233篇 |
2008年 | 1292篇 |
2007年 | 1113篇 |
2006年 | 1063篇 |
2005年 | 909篇 |
2004年 | 689篇 |
2003年 | 563篇 |
2002年 | 624篇 |
2001年 | 519篇 |
2000年 | 462篇 |
1999年 | 418篇 |
1998年 | 302篇 |
1997年 | 266篇 |
1996年 | 241篇 |
1995年 | 206篇 |
1994年 | 177篇 |
1993年 | 198篇 |
1992年 | 141篇 |
1991年 | 128篇 |
1990年 | 122篇 |
1989年 | 115篇 |
1988年 | 100篇 |
1987年 | 58篇 |
1986年 | 58篇 |
1985年 | 55篇 |
1984年 | 39篇 |
1983年 | 25篇 |
1982年 | 28篇 |
1981年 | 14篇 |
1980年 | 6篇 |
1979年 | 10篇 |
1978年 | 6篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1972年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
X. Zhou Y. Guo X. Sun X. Lei X. Chen Z. Liu Y. Zhang H. Jin Y. Luo S. X. Wen G. J. Yuan G. S. Li C. X. Yang 《Zeitschrift für Physik A Hadrons and Nuclei》1995,351(1):3-4
The high spin states of119Te, populated in110Pd(13C,4n) and110Pd(12C,3n) reactions, have been studied through -ray spectroscopy. The level scheme has been established upto a spin of 55/2. Three-quasiparticle states, based on g2
7/2h11/2 and g7/2d5/2h11/2 configurations, have been identified. The 35/2 and 39/2 states are suggested to be the fully aligned states constituted by five valence h11/2
3, g7/2, d5/2 quasiparticles. 相似文献
73.
Using the total human/mouse DNA as the probe, screening has been carried out three times with in situ plaque hybridization to obtain the single-copy DNA sequence from the human X chromosome genomic library. The effective rate of screening is 1. 45%. DNAs from clones containing single-copy inserts have been analyzed by a panel of hybrid cells with or without human X chromosome. Three segments, designated by DXFD52,73,75, are mapped to the X chromosome. DXFD52 has been precisely localized on Xq12-q13 with in situ chromosomal hybridization. DXFD52 has been partially sequenced. The results indicate that DXFD52 is a new isolated single-copy segment on the X chromosome. Great progress in the RFLPs study with DXFD52 has been achieved in the population of Chongqing, Sichuan Province. The results show that the DXFD52 can be used to detect the RFLP with Hind Ⅲ, Bgl Ⅱ, and Hinf Ⅰ. DXFD52 will be a potential "landmark" for the construction of the complete linkage map of human genome and the analysis of genomic s 相似文献
74.
75.
76.
77.
Hongwei Liu Xiangdong Liu KeXue Yuan KeSong Hu Yutau Chen 《International Journal of Infrared and Millimeter Waves》1993,14(8):1693-1699
A five-channel grating spectrometer for use in millimeter wave band (25100GHz) is described with its design theory of optical path, and measured results of insertion loss and resolving power. 相似文献
78.
79.
We investigate classical electronic collisions with a He(+) ion. Scattering functions, such as the scattering angle, collisional time, or energy of the outgoing electron, all exhibit an interesting hierarchial self-similar structure, which can be interpreted in terms of the indefinite number of electronic returns to the vicinity of the nucleus, encounters between electrons, and Keplerian excursions of electrons during the collisional processes. Based on this mechanism a binary coding is introduced to organize the dynamics of this three-body system and to provide an understanding of the self-similarity among generations of scale magnification, which yields escape rates that vary with the sectional cut into the parameter space. The self-similarity displayed within a single generation, on the other hand, can be simply tied to the periods of the two independent electronic excursions. The physical interpretation and the symbolic dynamics introduced here are generally useful for three-body collisional systems, including atomic, molecular, or stellar collisions. 相似文献
80.
Wang Yuan 《数学学报(英文版)》1993,9(4):382-389
Let
be a quadratic form with integer coefficients and letp denote a prime. Cochrane[1] proved that ifn≥4 then
has a solution
satisfying
, where
. The aim of the present paper is to generalize the above result to finite fields. 相似文献