全文获取类型
收费全文 | 359953篇 |
免费 | 4638篇 |
国内免费 | 1067篇 |
专业分类
化学 | 194689篇 |
晶体学 | 4496篇 |
力学 | 14864篇 |
综合类 | 12篇 |
数学 | 39156篇 |
物理学 | 112441篇 |
出版年
2021年 | 2789篇 |
2020年 | 3321篇 |
2019年 | 3652篇 |
2018年 | 4277篇 |
2017年 | 4445篇 |
2016年 | 6847篇 |
2015年 | 4344篇 |
2014年 | 6905篇 |
2013年 | 16893篇 |
2012年 | 12897篇 |
2011年 | 15463篇 |
2010年 | 10979篇 |
2009年 | 10857篇 |
2008年 | 14134篇 |
2007年 | 13711篇 |
2006年 | 13051篇 |
2005年 | 11700篇 |
2004年 | 10631篇 |
2003年 | 9464篇 |
2002年 | 8423篇 |
2001年 | 10333篇 |
2000年 | 7663篇 |
1999年 | 5721篇 |
1998年 | 4587篇 |
1997年 | 4518篇 |
1996年 | 4375篇 |
1995年 | 4249篇 |
1994年 | 4183篇 |
1993年 | 3997篇 |
1992年 | 4758篇 |
1991年 | 4578篇 |
1990年 | 4474篇 |
1989年 | 4449篇 |
1988年 | 4423篇 |
1987年 | 4442篇 |
1986年 | 4188篇 |
1985年 | 5489篇 |
1984年 | 5534篇 |
1983年 | 4525篇 |
1982年 | 4750篇 |
1981年 | 4632篇 |
1980年 | 4380篇 |
1979年 | 4871篇 |
1978年 | 4928篇 |
1977年 | 5004篇 |
1976年 | 4892篇 |
1975年 | 4566篇 |
1974年 | 4492篇 |
1973年 | 4629篇 |
1972年 | 3092篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Zlámalová M. Pitňa Lásková B. Vinarčíková M. Zukalová M. Kavan L. 《Journal of Solid State Electrochemistry》2022,26(3):639-647
Journal of Solid State Electrochemistry - The addition of nanocrystalline titanium dioxide (P90) to a cathode of Li/S cell enhances its voltammetric charge capacity by 19%, from which only a small... 相似文献
2.
Luan Nguyen Ngoc Kim Do Sang Yen Nguyen Dong 《Journal of Optimization Theory and Applications》2022,193(1):574-597
Journal of Optimization Theory and Applications - We consider the conic linear program given by a closed convex cone in an Euclidean space and a matrix, where vector on the right-hand side of the... 相似文献
3.
Physics of the Solid State - The phase transitions in the two-dimensional diluted Potts model with the number of spin states q = 3 are studied by computer simulation method. The systems... 相似文献
4.
Heßberger F. P. Antalic S. Giacoppo F. Andel B. Ackermann D. Block M. Heinz S. Khuyagbaatar J. Kojouharov I. Venhart M. 《The European Physical Journal A - Hadrons and Nuclei》2022,58(1):1-18
The European Physical Journal A - The goal of the present paper is twofold. First, a novel expansion many-body method applicable to superfluid open-shell nuclei, the so-called Bogoliubov in-medium... 相似文献
5.
Roopa K. P. Keshavamurthy K. Mahesh B. Veena K. P. Shankara B. S. Basavaiah K. 《Journal of Applied Spectroscopy》2022,89(4):809-818
Journal of Applied Spectroscopy - Three simple, sensitive, precise, and rapid spectrophotometric methods are developed and optimized for the assay of vardenafil in pharmaceutical formulations. The... 相似文献
6.
Temerdashev Z. A. Musorina T. N. Ovsepyan S. K. Korpakova I. G. 《Journal of Analytical Chemistry》2022,77(5):595-603
Journal of Analytical Chemistry - The work is dedicated to the determination of polyaromatic hydrocarbons (PAHs) in soils and bottom sediments by gas chromatography–mass spectrometry using... 相似文献
7.
JETP Letters - A simple fundamental modification of quantum key distribution protocols has been proposed: it is not required to protect the results of avalanche detectors from an eavesdropper, but... 相似文献
8.
Mohammad A. Khalilzadeh Soo Young Kim Ho Won Jang Rafael Luque Rajender S. Varma Richard A. Venditti Mohammadreza Shokouhimehr 《Materials Today Chemistry》2022
The requirement of green and sustainable materials to prepare heterogeneous catalysts has intensified for practical reasons over the past few decades. Carbohydrates are possibly the most plentiful and renewable organic materials in nature with inimitable physiochemical properties, plausible low-cost and large-scale production, and sustainability features could be exploited in the generation of nanostructured heterogeneous catalysts. This review article outlines the organic transformations catalyzed by diverse carbohydrate-based nanostructured catalysts in greener and environmentally friendly processes. Selected examples are highlighted for a variety of organic reactions exploiting the proposed catalysts’ reactivity and reusability, and interactions with the intrinsic nature of the applied carbohydrate supports; advantages and speculated challenges of the introduced catalysts are deliberated as well. 相似文献
9.
JETP Letters - A quasi-two-dimensional plasma crystal in (3 + 1) dimensions has been experimentally observed for the first time; i.e., three spatial coordinates of each microparticles of the... 相似文献
10.
JETP Letters - We present results of numerical investigations of high-order wave mixing/harmonic generation (HWM/HHG) with many-body interaction processes derived by a strong two-frequency circular... 相似文献