全文获取类型
收费全文 | 326924篇 |
免费 | 14149篇 |
国内免费 | 7691篇 |
专业分类
化学 | 166561篇 |
晶体学 | 4181篇 |
力学 | 18624篇 |
综合类 | 318篇 |
数学 | 48504篇 |
物理学 | 110576篇 |
出版年
2022年 | 2611篇 |
2021年 | 3600篇 |
2020年 | 4214篇 |
2019年 | 4065篇 |
2018年 | 12835篇 |
2017年 | 13497篇 |
2016年 | 10076篇 |
2015年 | 5789篇 |
2014年 | 6608篇 |
2013年 | 11778篇 |
2012年 | 16028篇 |
2011年 | 25577篇 |
2010年 | 16168篇 |
2009年 | 16069篇 |
2008年 | 21153篇 |
2007年 | 24212篇 |
2006年 | 9591篇 |
2005年 | 15220篇 |
2004年 | 10482篇 |
2003年 | 9327篇 |
2002年 | 7177篇 |
2001年 | 6197篇 |
2000年 | 5206篇 |
1999年 | 4292篇 |
1998年 | 3697篇 |
1997年 | 3575篇 |
1996年 | 3555篇 |
1995年 | 3143篇 |
1994年 | 2985篇 |
1993年 | 2618篇 |
1992年 | 2801篇 |
1991年 | 2828篇 |
1990年 | 2557篇 |
1989年 | 2439篇 |
1988年 | 2310篇 |
1987年 | 2143篇 |
1986年 | 2045篇 |
1985年 | 2521篇 |
1984年 | 2601篇 |
1983年 | 2110篇 |
1982年 | 2273篇 |
1981年 | 2146篇 |
1980年 | 2065篇 |
1979年 | 2183篇 |
1978年 | 2363篇 |
1977年 | 2152篇 |
1976年 | 2224篇 |
1975年 | 2111篇 |
1974年 | 2140篇 |
1973年 | 2176篇 |
排序方式: 共有10000条查询结果,搜索用时 460 毫秒
111.
Avramenko Andriy A. Shevchuk Igor V. Dmitrenko Nataliia P. Skitsko Ivan F. 《Journal of Thermal Analysis and Calorimetry》2022,147(22):12709-12719
Journal of Thermal Analysis and Calorimetry - The paper focuses on the analytical analysis of the propagation of a normal shock wave in an adiabatic gas flow with nanoparticles. A modified... 相似文献
112.
Jia Tian-Cong Guo Jin-Tao Wang Zhen Zhu Xiao-Shan Zhang Qian-Xin Chen Ping Yao Kun Lv Wen-Ying Liu Guo-Guang 《Journal of Radioanalytical and Nuclear Chemistry》2019,321(3):823-829
Journal of Radioanalytical and Nuclear Chemistry - In the present work the final products of coumarin radiation chemical transformation are investigated by chromatography. During radiolysis of... 相似文献
113.
Ding Q. Yao M. Wu Sh. Zeng M. Xue N. Wu D. Xu J. 《Journal of Applied Spectroscopy》2022,89(4):712-718
Journal of Applied Spectroscopy - Based on partial least squares (PLS) analysis, the effects of different smoothing points and different preprocessing methods on the accuracy and precision of the... 相似文献
114.
Transport in Porous Media - The theme of coupling problems for adsorption, absorption and thermochemical transport in porous media is very important for engineering applications. Based on the... 相似文献
115.
Mohammad Azam Saud I. Al-Resayes Agata Trzesowska-Kruszynska Rafal Kruszynski S.F. Adil N.K. Lokanath 《Journal of Saudi Chemical Society》2019,23(5):636-641
A new derivative of dioxouranium(VI) salen complex, [UO2(L)(pyridine)], where [L = N,N′-Bis(2-hydroxybenzylidene)-2,2-dimethyl-1,3-propanediamine] is synthesized and characterized by elemental analysis (C, H, N), FT-IR, ESI-MS spectrometry, UV/Vis, fluorescence, 1H and 13C NMR spectroscopy and thermal gravimetric (TG) study. Furthermore, the single crystal X-ray diffraction measurements of the complex were carried out at 100 and 273 K. The crystal structure measurements revealed that the complex has distorted pentagonal bipyramidal geometry with uranium atom located at the centre and bonded to two phenoxy oxygen and two azomethine nitrogen in tetradenate fashion and one nitrogen from pyridine making it seven coordinated. In addition, the photoluminescence property of the complex was also recorded. 相似文献
116.
Luo Dajuan Liu Bingqian Gao Rong Su Lixia Su Yonghuan 《Journal of Solid State Electrochemistry》2022,26(3):749-759
Journal of Solid State Electrochemistry - Cortisol, a steroid hormone, has been confirmed as a kind of biomarker that reflects the stress response of psychobiology and related adverse health... 相似文献
117.
An oriented tetrahedron defined on four vertices is a set of four cyclic triples with the property that any ordered pair of vertices is contained in exactly one of the cyclic triples. A tetrahedral quadruple system of order with index , denoted by , is a pair , where is an ‐set and is a set of oriented tetrahedra (blocks) such that every cyclic triple on is contained in exactly members of . A is pure if there do not exist two blocks with the same vertex set. When , the spectrum of a pure TQS has been completely determined by Ji. In this paper, we show that there exists a pure if and only if and . A corollary is that a simple also exists if and only if and . 相似文献
118.
Adly M. E. Gedawy E. M. El-Malah A. A. El-Telbany F. A. 《Russian Journal of Organic Chemistry》2019,55(8):1189-1196
Russian Journal of Organic Chemistry - Selenopheno[2,3-d]pyrimidine- and selenopheno[2,3-d][1,2,3]triazine-containing compounds were synthesized starting from... 相似文献
119.
120.
E. V. Shadrina O. N. Malinkina T. G. Khonina A. B. Shipovskaya V. I. Fomina E. Yu. Larchenko N. A. Popova I. G. Zyryanova L. P. Larionov 《Russian Chemical Bulletin》2015,64(7):1633-1639
The biomimetic sol—gel synthesis of silicon—chitosan-containing glycerohydrogels was carried out using silicon tetraglycerolate as a precursor. It was found that chitosan accelerates gel formation in weakly acidic media. In more acidic media, the kinetics of the process changes according to the curve with a maximum, which can be attributed to different mechanisms of silanol condensation before and after the isoelectric point. The investigated silicon—chitosan-containing glycerohydrogels exhibit antibacterial, anti-inflammatory, and wound healing activity. The synthesized hybrid glycerohydrogels are promising materials for biomedical applications. 相似文献