全文获取类型
收费全文 | 263篇 |
免费 | 3篇 |
国内免费 | 4篇 |
专业分类
化学 | 185篇 |
数学 | 31篇 |
物理学 | 54篇 |
出版年
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 5篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 8篇 |
2014年 | 3篇 |
2013年 | 6篇 |
2012年 | 9篇 |
2011年 | 15篇 |
2010年 | 9篇 |
2009年 | 9篇 |
2008年 | 10篇 |
2007年 | 16篇 |
2006年 | 13篇 |
2005年 | 8篇 |
2004年 | 13篇 |
2003年 | 14篇 |
2002年 | 10篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 8篇 |
1993年 | 5篇 |
1992年 | 7篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 4篇 |
1988年 | 7篇 |
1987年 | 2篇 |
1986年 | 6篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 6篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 3篇 |
1973年 | 1篇 |
排序方式: 共有270条查询结果,搜索用时 15 毫秒
101.
102.
103.
Dini F Martinelli E Paolesse R Filippini D Schild D Lundström I DI Natale C 《Analytical and bioanalytical chemistry》2012,402(2):823-832
Natural olfaction suggests that numerous replicas of small sensors can achieve large sensitivity. This concept of sensor redundancy
can be exploited by use of optical chemical sensors whose use of image sensors enables the simultaneous measurement of several
spatially distributed indicators. Digital image sensors split the framed scene into hundreds of thousands of pixels each corresponding
to a portion of the sensing layer. The signal from each pixel can be regarded as an independent sensor, which leads to a highly
redundant sensor array. Such redundancy can eventually be exploited to increase the signal-to-noise ratio. In this paper we
report an algorithm for reduction of the noise of pixel signals. For this purpose, the algorithm processes the output of groups
of pixels whose signals share the same time behavior, as is the case for signals related to the same indicator. To define
these groups of pixels, unsupervised clustering, based on classification of the indicator colors, is proposed here. This approach
to signal processing is tested in experiments on the chemical sensitivity of replicas of eight indicators spotted on to a
plastic substrate. Results show that the groups of pixels can be defined independently of the geometrical arrangement of the
sensing spots, and substantial improvement of the signal-to-noise ratio is obtained, enabling the detection of volatile compounds
at any location on the distributed sensing layer. 相似文献
104.
105.
106.
Herein, we report on a strategy for durable modification of the channel surface in microfluidic glass chips with the neutral hydrophilic-coating material poly(ethylene glycol) PEG-1M-100. Applied in microchip electrophoresis such PEG-coated devices exhibit a suppressed electroosmotic flow and reduced analyte adsorption. The PEG-coated chips were successfully applied in chip electrophoresis of FITC-labelled amines and amino acids and native proteins as well as in chiral separations. The performance of the coated chips was found to be superior compared with uncoated microchips. The coated chips exhibited high stability and the relative standard deviation of migration times in PEG-coated devices was less than 2%. 相似文献
107.
Detlev Poguntke 《Geometriae Dedicata》1992,43(1):83-91
First is presented a proof of Lie's theorem on solvable Lie algebras based on the nonexistence of the Heisenberg commutation relation. This is used to construct an effective procedure for finding all quotients of a given Lie algebra g which are isomorphic to the non-abelian two-dimensional algebra. As a byproduct one gets that the ideal (g) recently introduced by K. H. Hofmann is characteristic if the characteristic of the ground field is zero. 相似文献
108.
Figgen D Wedig A Stoll H Dolg M Eliav E Kaldor U 《The Journal of chemical physics》2008,128(2):024106
The four-component atomic intermediate-Hamiltonian Fock-space coupled cluster (IHFSCC) code of Landau et al. [J. Chem. Phys. 115, 6862 (2001)] has been adapted to two-component calculations with relativistic pseudopotentials of the energy-consistent variety. Recently adjusted energy-consistent pseudopotentials for group 11 and 12 transition elements as well as group 13 and 14 post-d main group elements, which were fitted to atomic valence spectra from four-component multiconfiguration Dirac-Hartree-Fock calculations, are tested in IHFSCC calculations for ionization potentials, electron affinities, and excitation energies of a variety of atoms and ions. Where comparison is possible, the deviations from experimental data are in good agreement with those found in previously published IHFSCC all-electron calculations: experimental data are usually reproduced within a few hundred wavenumbers. 相似文献
109.
We consider the problem of finding a zero of an accretive operator in a Banach space and prove strong convergence results for resolvents of the accretive operator. 相似文献
110.