全文获取类型
收费全文 | 143篇 |
免费 | 2篇 |
国内免费 | 6篇 |
专业分类
化学 | 15篇 |
力学 | 1篇 |
数学 | 103篇 |
物理学 | 32篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 5篇 |
2015年 | 7篇 |
2014年 | 8篇 |
2013年 | 10篇 |
2012年 | 5篇 |
2011年 | 4篇 |
2010年 | 5篇 |
2009年 | 6篇 |
2008年 | 6篇 |
2007年 | 9篇 |
2006年 | 8篇 |
2005年 | 9篇 |
2004年 | 5篇 |
2003年 | 10篇 |
2002年 | 10篇 |
2001年 | 2篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 5篇 |
1997年 | 1篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1936年 | 1篇 |
排序方式: 共有151条查询结果,搜索用时 15 毫秒
71.
We study Carathéodory-Herglotz functions whose values are continuous operators from a locally convex topological vector space which admits the factorization property into its conjugate dual space. We show how this case can be reduced to the case of functions whose values are bounded operators from a Hilbert space into itself. 相似文献
72.
The influence of magnesium doping on the properties of tetrakis(thiourea)nickel(II) chloride crystals has been described. The reduction in the intensity observed in powder X-ray diffraction of doped specimen and slight shifts in vibrational frequencies confirm the lattice stress as a result of doping. Surface morphological changes due to doping of the alkaline earth metal are observed by scanning electron microscopy. The incorporation of Mg(II) into the crystal lattice was confirmed by energy dispersive X-ray spectroscopy. Lattice parameters are determined by single crystal XRD analysis. The thermogravimetric and differential thermal analysis studies reveal the purity of the materials and no decomposition is observed up to the melting point. The crystal is further characterized by Kurtz powder technique and dielectric studies. 相似文献
73.
74.
Daniel Alpay Joseph A. Ball Israel Gohberg Leiba Rodman 《Integral Equations and Operator Theory》1992,15(3):349-377
The state space theory from linear control theory is used as a tool to describe the action of automorphisms of a certain form acting on rational matrix functions. This class consists of automorphisms representable as the composition of a linear fractional change of variable together with the operations of inverse-transpose, conjugation and an inner automorphism. We also describe in state space terms minimal factorizations within the class of functions of a certain associated group.Partially supported by NSF Grant 9000839 and by USA-Israel Binational Foundation Grant 88003094/2. 相似文献
75.
We extend to the hyperholomorphic case the notion of Schur functions and the corresponding realization theory. We introduce the notion of characteristic operator function for coisometric colligations between Hilbert spaces of hyperholomorphic functions. We show that every Schur function is the characteristic operator function of a coisometric colligation and vice-versa. To cite this article: D. Alpay et al., C. R. Acad. Sci. Paris, Ser. I 338 (2004). 相似文献
76.
77.
Steven?D?Buckingham Luanda?Pym Andrew?K?Jones Laurence?Brown Mark?SP?Sansom David?B?Sattelle Philip?C?BigginEmail author 《BMC neuroscience》2005,6(1):2
Background
Nicotinic acetylcholine receptors (nAChRs) are pentameric proteins that are important drug targets for a variety of diseases including Alzheimer's, schizophrenia and various forms of epilepsy. One of the most intensively studied nAChR subunits in recent years has been α7. This subunit can form functional homomeric pentamers (α7)5, which can make interpretation of physiological and structural data much simpler. The growing amount of structural, pharmacological and physiological data for these receptors indicates the need for a dedicated and accurate database to provide a means to access this information in a coherent manner. 相似文献78.
79.
In general, the estimation of the diffusion properties for diffusion tensor experiments (DTI) is accomplished via least squares estimation (LSE). The technique requires applying the logarithm to the measurements, which causes bad propagation of errors. Moreover, the way noise is injected to the equations invalidates the least squares estimate as the best linear unbiased estimate. Nonlinear estimation (NE), despite its longer computation time, does not possess any of these problems. However, all of the conditions and optimization methods developed in the past are based on the coefficient matrix obtained in a LSE setup. In this article, NE for DTI is analyzed to demonstrate that any result obtained relatively easily in a linear algebra setup about the coefficient matrix can be applied to the more complicated NE framework. The data, obtained using non-optimal and optimized diffusion gradient schemes, are processed with NE. In comparison with LSE, the results show significant improvements, especially for the optimization criterion. However, NE does not resolve the existing conflicts and ambiguities displayed with LSE methods. 相似文献
80.
In this paper, we introduce a non-commutative space of stochastic distributions, which contains the non-commutative white noise space, and forms, together with a natural multiplication, a topological algebra. Special inequalities which hold in this space allow to characterize its invertible elements and to develop an appropriate framework of non-commutative stochastic linear systems. 相似文献