全文获取类型
收费全文 | 964篇 |
免费 | 46篇 |
国内免费 | 7篇 |
专业分类
化学 | 673篇 |
晶体学 | 1篇 |
力学 | 22篇 |
数学 | 160篇 |
物理学 | 161篇 |
出版年
2023年 | 17篇 |
2022年 | 9篇 |
2021年 | 33篇 |
2020年 | 25篇 |
2019年 | 27篇 |
2018年 | 10篇 |
2017年 | 12篇 |
2016年 | 38篇 |
2015年 | 36篇 |
2014年 | 39篇 |
2013年 | 63篇 |
2012年 | 62篇 |
2011年 | 66篇 |
2010年 | 35篇 |
2009年 | 45篇 |
2008年 | 40篇 |
2007年 | 56篇 |
2006年 | 38篇 |
2005年 | 45篇 |
2004年 | 37篇 |
2003年 | 25篇 |
2002年 | 27篇 |
2001年 | 13篇 |
2000年 | 4篇 |
1999年 | 16篇 |
1998年 | 12篇 |
1997年 | 11篇 |
1996年 | 18篇 |
1995年 | 10篇 |
1994年 | 8篇 |
1993年 | 6篇 |
1992年 | 8篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 12篇 |
1985年 | 8篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 7篇 |
1980年 | 10篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 7篇 |
1975年 | 5篇 |
1974年 | 7篇 |
1972年 | 6篇 |
1971年 | 4篇 |
1930年 | 2篇 |
排序方式: 共有1017条查询结果,搜索用时 15 毫秒
921.
Nils Metzler‐Nolte 《Nachrichten aus der Chemie》2006,54(10):966-970
922.
923.
Carlsson N Winge AS Engström S Akerman B 《The journal of physical chemistry. B》2005,109(39):18628-18636
We used a cubic liquid crystal formed by the nonionic monoglyceride monoolein and water as a porous matrix for the electrophoresis of oligonucleotides. The diamond cubic phase is thermodynamically stable when in contact with a water-rich phase, which we exploit to run the electrophoresis in the useful submarine mode. Oligonucleotides are separated according to size and secondary structure by migration through the space-filling aqueous nanometer pores of the regular liquid crystal, but the comparatively slow migration means the cubic phase will not be a replacement for the conventional DNA gels. However, our demonstration that the cubic phase can be used in submarine electrophoresis opens up the possibility for a new matrix for electrophoresis of amphiphilic molecules. From this perspective, the results on the oligonucleotides show that water-soluble particles of nanometer size, typical for the hydrophilic parts of membrane-bound proteins, may be a useful separation motif. A charged contamination in the commercial sample of monoolein, most likely oleic acid that arises from its hydrolysis, restricts useful buffer conditions to a pH below 5.6. 相似文献
924.
Spatiotemporal patterns including accelerating fronts, rotating waves, and homogeneous oscillations evolve during the electrodissolution of metals like cobalt and iron that exhibit passivity under potentiostatic control. The nature of the patterns is determined by long-range (nonlocal) coupling through the electric field which in turn is influenced by the geometry of the electrochemical cell, the applied potential, and the conductivity of the electrolyte. A two-variable model in a three-dimensional geometry is presented which is able to simulate the essential features of the experimental system.(c) 2002 American Institute of Physics. 相似文献
925.
The neuropeptide leucine-enkephalin ([Leu5]-enkephalin) has been covalently labelled with the two organometallic Mo carbonyl complexes Mo(R-His)(allyl)(CO)2 (His = N delta,N,O-L-histidinate) and Mo(R-bpa)(CO)3 (bpa = bis(2-picolyl)a-mine) on the resin as the last step of a solid-phase synthesis scheme and in solution. 相似文献
926.
Hoffmann N Wismach C Jones PG Streubel R Huy NH Mathey F 《Chemical communications (Cambridge, England)》2002,(5):454-455
Synthesis of the first 1,2,3,4-azatriphospholene complex was achieved by heating a solution of a P-phenyl-substituted 7-phosphanorbornadiene tungsten complex and triphenylphosphonio cyanomethylide, whereby CH-insertion products were formed in a competing reaction; these results also provide first evidence for the ability of electrophilic terminal phosphanediyl complexes to react at the ylide carbon atom and at the carbonitrile nitrogen atom of Wittig-ylides having a nitrile functional group; the structures of both complexes were established through X-ray single-crystal diffraction studies. 相似文献
927.
928.
929.
930.
Calander N 《The journal of physical chemistry. B》2005,109(29):13957-13963
A theoretical approach is used to investigate the coupling of surface plasmon-coupled emission to Fabry-Perot resonance in the sample layer. Quantities investigated are emission angles, polarization, power levels, and fluorescence lifetimes. The results are compared to experimental findings. For comparison a layered structure without surface plasmons, possessing only dielectric Fabry-Perot resonances, is explored. This structure seems to be amenable to s-polarization only but is in principle loss-less and has more degrees of freedom for design and optimization. 相似文献