全文获取类型
收费全文 | 7649篇 |
免费 | 182篇 |
国内免费 | 213篇 |
专业分类
化学 | 3842篇 |
晶体学 | 27篇 |
力学 | 81篇 |
综合类 | 29篇 |
数学 | 2314篇 |
物理学 | 1751篇 |
出版年
2023年 | 16篇 |
2022年 | 83篇 |
2021年 | 72篇 |
2020年 | 177篇 |
2019年 | 361篇 |
2018年 | 123篇 |
2017年 | 338篇 |
2016年 | 123篇 |
2015年 | 140篇 |
2014年 | 168篇 |
2013年 | 333篇 |
2012年 | 276篇 |
2011年 | 491篇 |
2010年 | 318篇 |
2009年 | 563篇 |
2008年 | 602篇 |
2007年 | 526篇 |
2006年 | 542篇 |
2005年 | 373篇 |
2004年 | 272篇 |
2003年 | 238篇 |
2002年 | 329篇 |
2001年 | 277篇 |
2000年 | 205篇 |
1999年 | 156篇 |
1998年 | 139篇 |
1997年 | 124篇 |
1996年 | 129篇 |
1995年 | 72篇 |
1994年 | 62篇 |
1993年 | 35篇 |
1992年 | 35篇 |
1991年 | 32篇 |
1990年 | 16篇 |
1989年 | 17篇 |
1988年 | 11篇 |
1987年 | 14篇 |
1986年 | 15篇 |
1985年 | 24篇 |
1984年 | 21篇 |
1983年 | 13篇 |
1982年 | 10篇 |
1981年 | 27篇 |
1980年 | 24篇 |
1979年 | 26篇 |
1978年 | 26篇 |
1977年 | 20篇 |
1976年 | 11篇 |
1974年 | 10篇 |
1973年 | 14篇 |
排序方式: 共有8044条查询结果,搜索用时 15 毫秒
1.
Bingjie Chen Dr. Lianhai Zu Dr. Yao Liu Dr. Ruijing Meng Yutong Feng Prof. Chengxin Peng Feng Zhu Tianzi Hao Jiajia Ru Prof. Yonggang Wang Prof. Jinhu Yang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(8):3161-3166
Incorporating nanoscale Si into a carbon matrix with high dispersity is desirable for the preparation of lithium-ion batteries (LIBs) but remains challenging. A space-confined catalytic strategy is proposed for direct superassembly of Si nanodots within a carbon (Si NDs⊂C) framework by copyrolysis of triphenyltin hydride (TPT) and diphenylsilane (DPS), where Sn atomic clusters created from TPT pyrolysis serve as the catalyst for DPS pyrolysis and Si catalytic growth. The use of Sn atomic cluster catalysts alters the reaction pathway to avoid SiC generation and enable formation of Si NDs with reduced dimensions. A typical Si NDs⊂C framework demonstrates a remarkable comprehensive performance comparable to other Si-based high-performance half LIBs, and higher energy densities compared to commercial full LIBs, as a consequence of the high dispersity of Si NDs with low lithiation stress. Supported by mechanic simulations, this study paves the way for construction of Si/C composites suitable for applications in future energy technologies. 相似文献
2.
3.
《Journal of separation science》2018,41(6):1319-1337
The present review discusses the theory and application of van't Hoff analysis in chiral chromatography, with main focus on liquid chromatography. The topics considered include the physical meaning of van't Hoff equation's parameters, interpretation of thermodynamic data in terms of retention and enantioseparation mechanisms, abnormal behavior of van't Hoff plots, and best practices to avoid biased results. 相似文献
4.
5.
Faisal A.A. El-Orany 《Optics Communications》2006,263(2):235-238
We prove that the revival-collapse phenomenon occurring in the atomic inversion of the two-photon Jaynes-Cummings model, when the mode is initially prepared in the coherent state and the atom is in the excited state, can be obtained from the evolution of the quadrature squeezing of the four-photon Jaynes-Cummings model. 相似文献
6.
7.
8.
Summary In [6], we introduced and investigated the notions of strong β-I-open sets and strong β-I-continuous functions in ideal topological spaces. In this paper, we investigate further their important properties. 相似文献
9.
N. U. Aldiyarov K. K. Kadyrzhanov E. M. Yakushev V. S. Zhdanov 《Hyperfine Interactions》2005,164(1-4):67-72
The conditions for achievement of high resolving power of depth selective conversion electron Mössbauer spectroscopy method at a combined installation ‘electron spectrometer–nuclear gamma-resonance spectrometer’ have been obtained. There has been made a considerable step in development of the method at its realization at a magnetic sector electron spectrometer with double focusing, equipped with electron source (a sample under investigation) of large-area and position-sensitive detector. The paper presents a prospective symmetrical version of a magnetic sector electron spectrometer that allows realizing more completely possibilities of the method. It is noted that the proposed method is particularly valuable for investigations of nanosystems, nanostrutures that contain Mössbauer nuclei. 相似文献
10.
Dedushenko S. K. Makhina I. B. Mar'in A. A. Mukhanov V. A. Perfiliev Yu. D. 《Hyperfine Interactions》2004,158(1-4):417-421
A colourless quartz crystal doped with 57Fe3+ was obtained by hydrothermal synthesis in an NH4F solution. The crystal was transformed into violet amethyst by gamma-irradiation. The change in colour was accompanied by changes in the Mössbauer spectrum that can be interpreted as the conversion of trivalent iron into the tetravalent state: Fe3+→Fe4+.
相似文献