全文获取类型
收费全文 | 1105篇 |
免费 | 23篇 |
国内免费 | 14篇 |
专业分类
化学 | 728篇 |
晶体学 | 15篇 |
力学 | 12篇 |
数学 | 228篇 |
物理学 | 159篇 |
出版年
2022年 | 18篇 |
2021年 | 22篇 |
2020年 | 7篇 |
2019年 | 12篇 |
2018年 | 24篇 |
2017年 | 10篇 |
2016年 | 21篇 |
2015年 | 32篇 |
2014年 | 42篇 |
2013年 | 78篇 |
2012年 | 60篇 |
2011年 | 68篇 |
2010年 | 40篇 |
2009年 | 41篇 |
2008年 | 61篇 |
2007年 | 44篇 |
2006年 | 37篇 |
2005年 | 58篇 |
2004年 | 38篇 |
2003年 | 40篇 |
2002年 | 41篇 |
2001年 | 17篇 |
2000年 | 11篇 |
1999年 | 14篇 |
1997年 | 19篇 |
1996年 | 14篇 |
1995年 | 18篇 |
1994年 | 16篇 |
1993年 | 12篇 |
1992年 | 11篇 |
1991年 | 9篇 |
1990年 | 14篇 |
1989年 | 12篇 |
1988年 | 8篇 |
1987年 | 9篇 |
1986年 | 8篇 |
1985年 | 14篇 |
1984年 | 12篇 |
1983年 | 8篇 |
1982年 | 12篇 |
1981年 | 12篇 |
1980年 | 7篇 |
1979年 | 8篇 |
1978年 | 7篇 |
1977年 | 8篇 |
1975年 | 9篇 |
1974年 | 5篇 |
1968年 | 6篇 |
1965年 | 6篇 |
1962年 | 6篇 |
排序方式: 共有1142条查询结果,搜索用时 0 毫秒
991.
an ensemble of properly distanced micro mercury film electrodes (MMFE) was used in cyclic and anodic stripping voltammetry. the experimental results were compared with the anodic stripping theory, and the agreement was found to be satisfactory. The MMFE peaks (calculated per unit area) were higher, thinner and shifted towards more negative potentials compared with the large area mercury film electrode (LAMFE) peaks.The initial graphite electrode consisted of 65 independent micro-discs forming a circle, and was prepared from carbon fibres 4.66 μm in radius. The graphite multi-micro-disc electrode was quantitatively checked in a Fe(CN)63? solution under both chronoamperometric and voltammetric conditions. The deposition and oxidation of mercury is discussed also. 相似文献
992.
Zbigniew Płochocki Andrzej Mioduchowski Jacek F. MacZyński 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1995,46(3):339-354
The paper describes a theoretical discussion of the optical reflecting properties of an isotropic thermoelastic half-space subjected to an instantaneous heat pulse at a point of its surface (such a system is called the half-space thermal mirror). The fundamental optical properties of the mirror so obtained (i.e.—its aberration characteristic, including optical power and focal length), and their time evolution are derived in the paper. The half-space thermal mirror represents an optical device suffering rather high aberrations; the paraxial optics approximation, and criteria of its applicability for such a mirror are given. Possibilities of an application of the thermal mirror for determining the temperature conductivity of a material are considered. 相似文献
993.
994.
995.
Christopher Lehmann Judit. Debreczeni Gbor Bunkczi Miroslawa Dauter Zbigniew Dauter Lszl Vrtesy GeorgeM. Sheldrick 《Helvetica chimica acta》2003,86(5):1478-1487
The glycopeptide antibiotic decaplanin ( 1 ; formerly known as MM 47761 and M86‐1410) crystallizes in two P21 and two P6122 crystal forms, each with four monomers in the asymmetric unit, with solvent contents varying from 48 to 69%. Although with ca. 600 unique atoms, the structures are larger than typical small molecules, one was solved by direct methods. The other three were solved by typical macromolecular methods: single‐wavelength anomalous diffraction (SAD) of the Cl‐atoms present naturally in the structure, multiple‐wavelength anomalous diffraction (MAD) at the Br absorption edge for a crystal soaked in NaBr solution, and molecular replacement. There is evidence of appreciable radiation damage with loss of 20–30% of the covalent and ionic halogens affecting the synchrotron datasets that may even have unintentionally facilitated the MAD structure solution. The structures contain the dimer units typical of antibiotics related to vancomycin, but, in addition, there are a variety of further intermolecular interactions responsible for the polymorphy leading to intertwined 61‐helices in two of the crystal forms. Except for the sugars and some sidechains, the conformations of the 16 independent monomers are very similar. 相似文献
996.
997.
998.
Zbigniew Staszak 《光谱学快报》2013,46(9-10):981-991
An influence of the protic solvents on the electronic absorption spectra of chromium (III) complexes was investigated. The high correlation between dielectric constant of solvents and the crystal field parameter Dq as well as between refractive index and oscillator strength of d-d bands were observed. The significance of the ligand - second sphere interactions for studying of solvent effect on complex spectra was stated. 相似文献
999.
It is the aim of this paper to describe two different linearization procedures for the Boltzmann equation in ak=0 Robertson-Walker space-time. These procedures are discussed with a view to obtaining an asymptotic form of the Boltzmann equation for the late stages of cosmic expansion where the behavior appropriate to a nonrelativistic gas is encountered. Using the asymptotic kinetic equations, a necessary and sufficient condition is formulated under which every small perturbation of the equilibrium distribution function, either classical or relativistic, decays to zero as time goes on. The same condition can be extracted from each of two linearization procedures, and in this sense a comparison is made of these approaches which reveals mutual agreement. Also, applying an asymptotic theory of the Einstein-Boltzmann system, we show that the final state of a gas is dust (i.e., a fluid with zero temperature and pressure). Comparison with the predictions of the Eckart fluid model is briefly presented. 相似文献
1000.