全文获取类型
收费全文 | 100558篇 |
免费 | 1464篇 |
国内免费 | 1062篇 |
专业分类
化学 | 36980篇 |
晶体学 | 952篇 |
力学 | 8419篇 |
综合类 | 72篇 |
数学 | 35046篇 |
物理学 | 21615篇 |
出版年
2022年 | 308篇 |
2021年 | 382篇 |
2020年 | 466篇 |
2019年 | 494篇 |
2018年 | 10926篇 |
2017年 | 10670篇 |
2016年 | 6729篇 |
2015年 | 1303篇 |
2014年 | 974篇 |
2013年 | 1238篇 |
2012年 | 4690篇 |
2011年 | 11369篇 |
2010年 | 6440篇 |
2009年 | 6777篇 |
2008年 | 7362篇 |
2007年 | 9525篇 |
2006年 | 858篇 |
2005年 | 1850篇 |
2004年 | 2000篇 |
2003年 | 2497篇 |
2002年 | 1587篇 |
2001年 | 786篇 |
2000年 | 701篇 |
1999年 | 528篇 |
1998年 | 497篇 |
1997年 | 458篇 |
1996年 | 479篇 |
1995年 | 386篇 |
1994年 | 314篇 |
1993年 | 373篇 |
1992年 | 318篇 |
1991年 | 334篇 |
1990年 | 333篇 |
1989年 | 327篇 |
1986年 | 298篇 |
1985年 | 323篇 |
1984年 | 326篇 |
1982年 | 316篇 |
1980年 | 303篇 |
1979年 | 344篇 |
1978年 | 363篇 |
1977年 | 338篇 |
1976年 | 420篇 |
1975年 | 375篇 |
1974年 | 399篇 |
1973年 | 421篇 |
1972年 | 386篇 |
1971年 | 339篇 |
1970年 | 321篇 |
1969年 | 305篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Chuprin A. S. Belova S. A. Bugaenko M. G. Vologzhanina A. V. Loktev A. S. Voloshin Ya. Z. Buznik V. M. Dedov A. G. 《Kinetics and Catalysis》2022,63(1):108-116
Kinetics and Catalysis - A new ruthenium(II) cage complex with polar terminal groups in the apical substituents has been synthesized; the molecular design of the complex contributes to the... 相似文献
2.
Moroz Ya. A. Lozinskyy N. S. Lopanov A. N. Chebyshev K. A. 《Russian Journal of General Chemistry》2022,92(1):101-107
Russian Journal of General Chemistry - Tungstophosphatozincates with the Keggin anion structure Kt5[PW11O39Zn(H2O)]?nH2O, Kt = Rb+, Cs+, (CH3)4N+; (C2H5)4N+ were synthesized. Their... 相似文献
3.
Yujie Xiong 《中国科学:化学(英文版)》2022,65(1):5-6
Photoelectrochemical(PEC)technique represents a promising approach to chemical transformation by harvesting sustainable solar energy.Despite the wide applications of PEC systems such as environmental remediation and solar energy conversion,the reported PEC reactions are dominated by the radical-based processes that are initiated by the single electron transfer between photo-induced carriers and adsorbed species on photoelectrode surface[1,2].For instance,hydroxyl radicals are often involved in the PEC oxidation reactions.As well known,it is a grand challenge to control the formation and evolution rates of radicals,which inevitably leads to the unsatisfactory product selectivity of PEC reactions.Naturally,such a circumstance brings about a question to the research community whether a different mechanism can be established to sustain efficient and selective oxygenation.Recently,based on their previous findings on PEC water oxidation[3,4],Zhao and coworkers[5]reported that many substrates can be oxidized in an oxygen atom transfer(OAT)pathway,a non-radical two electron process,to oxygenated products byα-Fe2O3 photoanodes. 相似文献
4.
In the paper, the authors establish several integral representations for the generating functions of the large and little Schröder numbers and for the large and little Schröder numbers. 相似文献
5.
Mesoscopic modeling at the pore scale offers great promise in exploring the underlying structure transport performance of flow through porous media. The present work studies the fluid flow subjected to capillarity-induced resonance in porous media characterized by different porous structure and wettability. The effects of porosity and wettability on the displacement behavior of the fluid flow through porous media are discussed. The results are presented in the form of temporal evolution of percentage saturation and displacement of the fluid front through porous media. The present study reveals that the vibration in the form of acoustic excitation could be significant in the mobilization of fluid through the porous media. The dependence of displacement of the fluid on physicochemical parameters like wettability of the surface, frequency along with the porosity is analyzed. It was observed that the mean displacement of the fluid is more in the case of invading fluid with wetting phase where the driving force strength is not so dominant. 相似文献
6.
7.
Sarah Peluse 《Israel Journal of Mathematics》2018,227(1):379-396
We prove that the group of diffeomorphisms of the interval [0, 1] contains surface groups whose action on (0, 1) has no global fix point and such that only countably many points of the interval (0, 1) have non-trivial stabiliser. 相似文献
8.
9.
10.