全文获取类型
收费全文 | 1191篇 |
免费 | 57篇 |
国内免费 | 4篇 |
专业分类
化学 | 973篇 |
晶体学 | 11篇 |
力学 | 18篇 |
数学 | 69篇 |
物理学 | 181篇 |
出版年
2023年 | 4篇 |
2022年 | 19篇 |
2021年 | 31篇 |
2020年 | 15篇 |
2019年 | 38篇 |
2018年 | 21篇 |
2017年 | 16篇 |
2016年 | 41篇 |
2015年 | 46篇 |
2014年 | 39篇 |
2013年 | 79篇 |
2012年 | 91篇 |
2011年 | 101篇 |
2010年 | 65篇 |
2009年 | 61篇 |
2008年 | 91篇 |
2007年 | 68篇 |
2006年 | 61篇 |
2005年 | 46篇 |
2004年 | 57篇 |
2003年 | 41篇 |
2002年 | 48篇 |
2001年 | 24篇 |
2000年 | 20篇 |
1999年 | 20篇 |
1998年 | 12篇 |
1997年 | 8篇 |
1996年 | 14篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 11篇 |
1992年 | 5篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有1252条查询结果,搜索用时 15 毫秒
231.
232.
Correlated electronic structure of LaO1-xFxFeAs 总被引:1,自引:0,他引:1
We compute the electronic structure, momentum resolved spectral function and optical conductivity of the new superconductor LaO1-xFxFeAs within the combination of the density functional theory and dynamical mean field theory. We find that the compound in the normal state is a strongly correlated metal and the parent compound is a bad metal at the verge of the metal insulator transition. We argue that the superconductivity is not phonon mediated. 相似文献
233.
Using a kinetic Monte Carlo method, we simulate binary film (A0.5B0.5/A) growth on an L×L square lattice with the focus on the domain growth behaviour. We compute the average domain area, A(t), as a measure of domain size. For a sufficiently large system, we find that A(t) grows with a power law in time with A(t)∼t2/3 after the initial transient time. This implies that the dynamic exponent for domain growth with non-conserved order parameter is z=3, a value which was theoretically predicted for the conserved order parameter case. Further analysis reveals that such a power-law behaviour emerges because the order parameter is approximately conserved after the early stage of growth. 相似文献
234.
El-Khouly ME Shim SH Araki Y Ito O Kay KY 《The journal of physical chemistry. B》2008,112(13):3910-3917
Photoinduced intramolecular electron-transfer events of the newly synthesized subphthalocyanine-triphenylamine-fullerene triad (SubPc-TPA-C60) and subphthalocyanine-triphenylamine-bisfullerene tetrad (SubPc-TPA-(C(60))(2)) were studied. The geometric and electronic structures of the triad were probed by ab initio B3LYP/3-21G method, which predicts SubPc-TPA(*+)-C(60)(*-) as a stable charge-separated state. The photoinduced events via the excited singlet state of SubPc were monitored by time-resolved emission measurements as well as transient absorption techniques. Efficient charge-separations via the excited states of SubPc were observed with the rates of approximately 10(10) s(-)1. Compared with the SubPc-TPA dyad, a long-lived charge-separated state was observed for the SubPc-TPA-C(60) triad with the lifetime of the radical ion pairs (tau(RIP)) of 670 ns in benzonitrile. Interestingly, further charge stabilization was achieved in the charge-separated state of SubPc-TPA-(C(60))(2), in which the tau(RIP) was found to be 1050 ns in benzonitrile. 相似文献
235.
A reliable multiplex assay procedure to detect human genetic mutations in the breast cancer susceptibility gene BRCA1 using zip-code microarrays and single base extension (SBE) reactions is described. Multiplex PCR amplification was performed
to amplify the genomic regions containing the mutation sites. The PCR products were then employed as templates in subsequent
multiplex SBE reactions using bifunctional primers carrying a unique complementary zip sequence in addition to a mutation-site-specific
sequence. The SBE primers, terminating one base before their mutation sites, were extended by a single base at a mutation
site with a corresponding biotin-labeled ddNTP. Hybridization of the SBE products to zip-code microarrays was followed by
staining with streptavidin–Cy3, leading to successful genotyping of several selected BRCA1 mutation sites with wild-type and heterozygote mutant samples from breast cancer patients. This work has led to the development
of a reliable DNA microarray-based system for the diagnosis of human genetic mutations.
Cheulhee Jung and Seong-Chun Yim contributed equally to this work. 相似文献
236.
237.
M. S. Balathanigaimani Min-Joo Lee Wang-Geun Shim Jae-Wook Lee Hee Moon 《Adsorption》2008,14(4-5):525-532
Methane adsorptions on various synthesized and commercial activated carbons were assessed in a volumetric apparatus for the design of an efficient adsorbed natural gas storage system. Based on the methane adsorption equilibrium results from different carbon based materials, a monolith was also produced from RP-20. Dynamic studies were also performed for the prepared monolith and the pelletized commercial Norit-B4 activated carbon. The temperature variation in RP-20 monolith was analyzed and compared with those of Norit-B4 and a blank test, which consisted of a run without a sample. The temperature variation in RP-20 monolith was quite high compared to that observed with Norit-B4 and the blank test because of a higher isosteric heat of adsorption and a high packing density. 相似文献
238.
Lee JY Kim HJ Jung JH Sim W Lee SS 《Journal of the American Chemical Society》2008,130(42):13838-13839
Solvato-PL switching and shrinking-and-opening process: we present two CuI coordination polymers of calix[4]-bis-monothiacrown (L) obtained in the absence (1) and presence (2) of KI. The structures show not only very unusual CuI-based network arrangements but also unique reversible photolunimescence switching behavior induced by removal of coordinated solvent. Furthermore, upon inclusion of K+ ions the crown ring shrinks leading to "opening" of opposite aromatic rings in the host calixarene unit, rare behavior for this class of compound. 相似文献
239.
Go Gwang Sub Lee Hong Joo Moon Dong Ju Kim Young Chul 《Research on Chemical Intermediates》2016,42(1):289-304
Research on Chemical Intermediates - In this study, we focused on the catalytic activity, stability, and kinetics of glycerol steam reforming (GSR) for the hydrogen production over... 相似文献
240.
Swarbhanu Sarkar Yeong Su Ha Nisarg Soni Gwang Il An Woonghee Lee Min Hwan Kim Phuong Tu Huynh Heesu Ahn Nikunj Bhatt Yong Jin Lee Jung Young Kim Kwon Moo Park Isao Ishii Shin‐Geol Kang Jeongsoo Yoo 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(32):9511-9516
Hydrogen sulfide (H2S) has multifunctional roles as a gas signaling molecule in living systems. However, the efficient detection and imaging of H2S in live animals is very challenging. Herein, we report the first radioisotope‐based immobilization technique for the detection, quantification, and in vivo imaging of endogenous H2S. Macrocyclic 64Cu complexes that instantly reacted with gaseous H2S to form insoluble 64CuS in a highly sensitive and selective manner were prepared. The H2S concentration in biological samples was measured by a thin‐layer radiochromatography method. When 64Cu–cyclen was injected into mice, an elevated H2S concentration in the inflamed paw was clearly visualized and quantified by Cerenkov luminescence and positron emission tomography (PET) imaging. PET imaging was also able to pinpoint increased H2S levels in a millimeter‐sized infarcted lesion of the rat heart. 相似文献