全文获取类型
收费全文 | 1830篇 |
免费 | 356篇 |
国内免费 | 185篇 |
专业分类
化学 | 1003篇 |
晶体学 | 21篇 |
力学 | 105篇 |
综合类 | 3篇 |
数学 | 315篇 |
物理学 | 924篇 |
出版年
2024年 | 5篇 |
2023年 | 113篇 |
2022年 | 99篇 |
2021年 | 130篇 |
2020年 | 135篇 |
2019年 | 76篇 |
2018年 | 95篇 |
2017年 | 113篇 |
2016年 | 129篇 |
2015年 | 128篇 |
2014年 | 148篇 |
2013年 | 138篇 |
2012年 | 152篇 |
2011年 | 135篇 |
2010年 | 114篇 |
2009年 | 103篇 |
2008年 | 55篇 |
2007年 | 62篇 |
2006年 | 100篇 |
2005年 | 60篇 |
2004年 | 39篇 |
2003年 | 48篇 |
2002年 | 34篇 |
2001年 | 46篇 |
2000年 | 29篇 |
1999年 | 35篇 |
1998年 | 23篇 |
1997年 | 11篇 |
1996年 | 12篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1990年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有2371条查询结果,搜索用时 15 毫秒
31.
A. López A. Scholz Z. Z. Sun J. Schliemann 《The European Physical Journal B - Condensed Matter and Complex Systems》2013,86(9):1-8
We analyze the role of an ac-driven Rashba spin-orbit coupling in monolayer graphene including a spin-dependent mass term. Using the Magnus expansion as a semi-analytical approximation scheme a full account of the quasienergie spectrum of spin states is given. We discuss the subtleties arising in correctly applying the Magnus expansion technique in order to determine the quasienergy spectrum. Comparison to the exact numerical solution gives appropriate boundaries to the validity of the Magnus expansion solution. 相似文献
32.
ABSTRACTHerein, we develop a switchable peptide-equipped protein/cucurbit[7]uril (CB[7]) supramolecular assembly as novel targeted drug vector. Specifically, bovine serum albumin (BSA) is used to interact with CB[7], serving as the core of drug vector. Then, a peptide shield layer is formed on the surface of BSA/CB[7], yielding peptide-equipped supramolecular assembly (Pep@BSA@CB[7]). The equipped peptide shield layer is composed of switchable peptide probes consisting of a polycationic cell-penetrating peptide (CPP) motif, a polyanionic motif and a linking motif, and therefore provides a variety of desirable properties. First, the CPP motif displays excellent cell penetration ability and can facilitate internalisation of the drug vector. Secondly, the polyanionic motif performs intramolecular electrostatic interaction with CPP motif and thereby can reduce non-targeted delivery towards normal cells. Thirdly, the linking motif can be specifically cleaved by matrix metalloproteinases 2 that is up-regulated in tumour microenvironment, thus enabling precise cancer-targeting. As a consequent, Pep@BSA@CB[7] can serve as a promising drug vector that exhibits superior targeting ability and high uptake efficiency towards cancer cells, which may be of great potential in cancer-targeted treatment. 相似文献
33.
In this paper, for a kind of risk models with heavy-tailed and delayed claims, we derive the asymptotics of the infinite-time ruin probability and the uniform asymptotics of the finite-time ruin probability. The numerical simulation results are also presented. The results of theoretical analysis and numerical simulation
show that the influence of the delay for the claim payment is nearly negligible to the ruin probability when the initial capital and running-time are all large. 相似文献
34.
Cover Picture: Open‐Pore Two‐Dimensional MFI Zeolite Nanosheets for the Fabrication of Hydrocarbon‐Isomer‐Selective Membranes on Porous Polymer Supports (Angew. Chem. Int. Ed. 25/2016) 下载免费PDF全文
Han Zhang Prof. Qiang Xiao Prof. Xianghai Guo Prof. Najun Li Prashant Kumar Neel Rangnekar Mi Young Jeon Prof. Shaeel Al‐Thabaiti Prof. Katabathini Narasimharao Prof. Sulaiman Nasir Basahel Prof. Berna Topuz Frank J. Onorato Prof. Christopher W. Macosko Prof. K. Andre Mkhoyan Prof. Michael Tsapatsis 《Angewandte Chemie (International ed. in English)》2016,55(25):7009-7009
35.
Henry reaction is one of the most classical reactions to construct synthetically useful product nitro alcohol, which as a privileged skeleton is widely distributed in various pharmaceuticals. This review summarizes the recent progress of copper-catalyzed asymmetric Henry reaction from 2011 to 2016. The significant progress that has been made in this area will be highlighted and some of challenges that the author believes may be hindering further progress will be revealed. 相似文献
36.
Dr. Yuyang Zhou Assistant Prof. Junli Jia Prof. Xiaomei Wang Dr. Weiqiang Guo Prof. Zhengying Wu Prof. Nan Xu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(47):16796-16800
Seven luminescent iridium(III) complexes were prepared to investigate the relationships between chemical structures and properties of protein staining. For the first time, the effect of the main ligand, the π conjugation effect of the ancillary ligand, and the charge effect of organometallic complexes on protein staining has been revealed. Most importantly, this study gives the first experimental evidence of the potential applications of charge‐neutral organometallic complexes in protein staining, which could open an avenue of exploiting novel protein staining agents in the future. 相似文献
37.
Hengfeng Fan Huafeng Zhou Chaolong Ma Yiqing Huang Yan Li 《Molecular Crystals and Liquid Crystals》2014,593(1):232-242
The effect of humidity on the holographic grating diffraction efficiency and transmittance kinetics in the E204Q BR gelatin film is investigated. We found a correlation between the accumulation of the red-light absorbing O intermediate in the later part of the E204Q BR photocycle and sharpness (decay to the steady-state) of the holographic recording kinetics. As shown, at humidity exceeding 95% the ratio between the peak and steady-state of the diffraction efficiency for the weak probe beam (670 nm) can reach 8.7 in the E204Q BR film, which is sufficient for realization of an efficient novelty filter. 相似文献
38.
Inside Back Cover: Ultrathin WS2 Nanoflakes as a High‐Performance Electrocatalyst for the Hydrogen Evolution Reaction (Angew. Chem. Int. Ed. 30/2014) 下载免费PDF全文
39.
The purpose of this paper is to study a new two-step iterative scheme with mean errors of mixed type for two asymptotically nonexpansive self-mappings and two asymptotically nonexpansive nonself-mappin... 相似文献
40.