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排序方式: 共有158条查询结果,搜索用时 15 毫秒
81.
We consider the linear stochastic wave equation with spatially homogeneous Gaussian noise, which is fractional in time with index H>1/2. We show that the necessary and sufficient condition for the existence of the solution is a relaxation of the condition obtained in Dalang (1999) [10], where the noise is white in time. Under this condition, we show that the solution is L2(Ω)-continuous. Similar results are obtained for the heat equation. Unlike in the white noise case, the necessary and sufficient condition for the existence of the solution in the case of the heat equation is different (and more general) than the one obtained for the wave equation. 相似文献
82.
83.
For each n≥1, let {X j,n }1≤j≤n be a sequence of strictly stationary random variables. In this article, we give some asymptotic weak dependence conditions for the convergence in distribution of the point process $N_{n}=\sum_{j=1}^{n}\delta_{X_{j,n}}For each n≥1, let {X
j,n
}1≤j≤n
be a sequence of strictly stationary random variables. In this article, we give some asymptotic weak dependence conditions
for the convergence in distribution of the point process
Nn=?j=1ndXj,nN_{n}=\sum_{j=1}^{n}\delta_{X_{j,n}}
to an infinitely divisible point process. From the point process convergence we obtain the convergence in distribution of
the partial sum sequence S
n
=∑
j=1
n
X
j,n
to an infinitely divisible random variable whose Lévy measure is related to the canonical measure of the limiting point process.
As examples, we discuss the case of triangular arrays which possess known (row-wise) dependence structures, like the strong
mixing property, the association, or the dependence structure of a stochastic volatility model. 相似文献
84.
The solution for a line source of oscillatory strength kept at the origin in a wall bounding a semi-infinite viscous imcompressible stratified fluid is presented in an integral form. The behaviour of the flow at far field and near field is studied by an asymptotic expansion procedure. The streamlines for different parameters are drawn and discussed. The real characteristic straight lines present in the inviscid problem are modified by the viscosity and the solutions obtained are valid even at the resonance frequency. 相似文献
85.
Balan E Mauri F Lemaire C Brouder C Guyot F Saitta AM Devouard B 《Physical review letters》2002,89(17):177401
Chrysotile asbestos is formed by densely packed bundles of multiwall hollow nanotubes. Each wall in the nanotubes is a cylindrically wrapped layer of Mg(3)Si(2)O(5)(OH)(4). We show by experiment and theory that the infrared spectra of chrysotile present multiple ionic-plasmon resonances in the Si-O stretching bands. These collective charge excitations are universal features of the nanotubes that are obtained by cylindrically wrapping an anisotropic material. The multiple plasmons can be observed if the width of the resonances is sufficiently small as in chrysotile. 相似文献
86.
87.
In this article we introduce the class of Markov jump random c.d.f.’s as a sub-class of the Q-Markov prior distributions studied in R.M. Balan [Q-Markov random probability measures and their posterior distributions, Stochastic Process. Appl. 109 (2004) 296–316]. Our main result states that if the prior distribution of a sample is a Markov jump process, then the posterior distribution can also be viewed as the distribution of a Markov jump process, whose transition mechanism and infinitesimal behavior have been updated in the light of the new data. 相似文献
88.
Pachfule P Balan BK Kurungot S Banerjee R 《Chemical communications (Cambridge, England)》2012,48(14):2009-2011
The loading of a Zn-terephthalate based MOF in the inner cavity as well as on the outer walls of a hollow carbon nanofiber (CNF) creates MOF@CNF hybrids. This hybrid 'MOF@CNF' displayed improved thermal stability as well as gas adsorption compared to the individual counterparts. 相似文献
89.
Hironobu Ozawa Dr. Masayuki Kobayashi Bijitha Balan Dr. Shigeyuki Masaoka Dr. Ken Sakai Prof. Dr. 《化学:亚洲杂志》2010,5(8):1860-1869
The mechanism of photoinduced hydrogen evolution from water driven by the first photo‐hydrogen‐evolving molecular catalyst ( 1 ), given by a coupling of [Ru(bpy)2(5‐amino‐phen)]2+ and [PtCl2(4,4′‐dicarboxy‐bpy)] (bpy=2,2′‐bipyridine, phen=1,10‐phenanthroline), was investigated in detail. The H2 evolution rate was found to obey Michaelis–Menten enzymatic kinetics with regard to the concentration of EDTA (ethylenediamine tetra‐acetic acid disodium salt, sacrificial electron donor), which indicates that an ion‐pair formation between the dicationic 1 and the dianionic form of EDTA (pH 5) is a key step leading to H2 formation. A 2:1 coupling product of 1 and ethylenediamine (i.e., a {RuII2PtII2} complex 2 ) was found to show significantly higher photo‐hydrogen‐evolving (PHE) activity than 1 , which revealed the validity of the bimolecular activation proposed in our previous study. The PHE activity of 2 was also observed to be linear to the concentration of 2 , which indicates that H2 formation through the intermolecular path competes with the intramolecular path. Molecular orbital diagrams, conformational features, and Pt???H(water or acetic acid) hydrogen bonds were characterized by DFT calculations. 相似文献
90.
Ioan Valentin Moise Marian Virgolici Constantin Daniel Negut Mihaela Manea Mioara Alexandru Laura Trandafir Florina Lucica Zorila Catalina Mihaela Talasman Daniela Manea Steluta Nisipeanu Maria Haiducu Zamfir Balan 《Radiation Physics and Chemistry》2012,81(8):1045-1050
Museums, libraries and archives are preserving documents that are slowly degrading due to the inherent ageing of the cellulose substrate or to the technological errors of the past (acid paper, iron gall ink). Beside this, large quantities of paper are rapidly damaged by biological attacks following natural disasters and improper storage conditions.The treatment of paper documents with ionizing radiation can be used for mass decontamination of cultural heritage items but conservators and restaurators are still reserved because of the radiation induced degradation.We conducted a study for establishing the dose needed for the effective treatment of paper documents, taking into account the biological burden and the irradiation effects on paper structure. We used physical testing specific to paper industry and less destructive analytical methods (thermal analysis).Our results show that an effective treatment can be performed with doses lower than 10 kGy. Old paper appears to be less affected by gamma radiation than recent paper but the sampling is highly affected by the non-uniform degree of the initial degradation status. The extent of testing for degradation and the magnitude of acceptable degradation should take into account the biological threat and the expected life time of the paper documents. 相似文献