全文获取类型
收费全文 | 677篇 |
免费 | 26篇 |
国内免费 | 5篇 |
专业分类
化学 | 550篇 |
晶体学 | 4篇 |
力学 | 11篇 |
数学 | 72篇 |
物理学 | 71篇 |
出版年
2023年 | 2篇 |
2022年 | 10篇 |
2021年 | 14篇 |
2020年 | 11篇 |
2019年 | 6篇 |
2018年 | 7篇 |
2017年 | 3篇 |
2016年 | 17篇 |
2015年 | 22篇 |
2014年 | 19篇 |
2013年 | 32篇 |
2012年 | 45篇 |
2011年 | 71篇 |
2010年 | 29篇 |
2009年 | 23篇 |
2008年 | 45篇 |
2007年 | 54篇 |
2006年 | 44篇 |
2005年 | 37篇 |
2004年 | 42篇 |
2003年 | 40篇 |
2002年 | 33篇 |
2001年 | 10篇 |
2000年 | 7篇 |
1999年 | 5篇 |
1998年 | 7篇 |
1997年 | 10篇 |
1996年 | 10篇 |
1995年 | 5篇 |
1994年 | 6篇 |
1993年 | 8篇 |
1992年 | 1篇 |
1991年 | 5篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1975年 | 2篇 |
1974年 | 2篇 |
排序方式: 共有708条查询结果,搜索用时 265 毫秒
151.
Tanaka,(18) showed a way to relate the measure solution {P
t
}
t
of a spatially homogeneous Boltzmann equation of Maxwellian molecules without angular cutoff to a Poisson-driven stochastic differential equation: {P
t
} is the flow of time marginals of the solution of this stochastic equation. In the present paper, we extend this probabilistic interpretation to much more general spatially homogeneous Boltzmann equations. Then we derive from this interpretation a numerical method for the concerned Boltzmann equations, by using easily simulable interacting particle systems. 相似文献
152.
Eric Osei-Agyemang Jean-Franois Paul Romain Lucas Sylvie Foucaud Sylvain Cristol Anne-Sophie Mamede Nicolas Nuns Ahmed Addad 《Molecules (Basel, Switzerland)》2022,27(9)
The mechanical and physical properties of zirconium carbide (ZrC) are limited to its ability to deteriorate in oxidizing environments. Low refractory oxides are typically formed as layers on ZrC surfaces when exposed to the slightest concentrations of oxygen. However, this carbide has a wide range of applications in nuclear reactor lines and nozzle flaps in the aerospace industry, just to name a few. To develop mechanically strong and oxygen-resistant ZrC materials, the need for studying and characterizing the oxidized layers, with emphasis on the interfacial structure between ZrC and the oxidized phases, cannot be understated. In this paper, the ZrC(111)//c-ZrO2 (111) interface was studied by both finite temperature molecular dynamic simulation and DFT. The interfacial mechanical properties were characterized by the work of adhesion which revealed a Zr|OO|Zr|OO//ZrC(111) interface model as the most stable with an oxygen layer from ZrO2 being deposited on the ZrC(111) surface. Further structural analysis at the interface showed a crack in the first ZrO2 layer at the interfacial region. Investigations of the electronic structure using the density of state calculations and Bader charge analysis revealed the interfacial properties as local effects with no significant impacts in the bulk regions of the interface slab. 相似文献
153.
Mathilde Briday Franois Hall Lauriane Lecoq Sylvie Radix Juliette Martin Roland Montserret Marie Dujardin Marie-Laure Fogeron Michael Nassal Beat H. Meier Thierry Lomberget Anja Bckmann 《Chemical science》2022,13(30):8840
Hepatitis B virus (HBV) is a small enveloped retrotranscribing DNA virus and an important human pathogen. Its capsid-forming core protein (Cp) features a hydrophobic pocket proposed to be central notably in capsid envelopment. Indeed, mutations in and around this pocket can profoundly modulate, and even abolish, secretion of enveloped virions. We have recently shown that Triton X-100, a detergent used during Cp purification, binds to the hydrophobic pocket with micromolar affinity. We here performed pharmacomodulation of pocket binders through systematic modifications of the three distinct chemical moieties composing the Triton X-100 molecule. Using NMR and ITC, we found that the flat aromatic moiety is essential for binding, while the number of atoms of the aliphatic chain modulates binding affinity. The hydrophilic tail, in contrast, is highly tolerant to changes in both length and type. Our data provide essential information for designing a new class of HBV antivirals targeting capsid–envelope interactions.Small-molecule binding to the Hepatitis B virus core protein hydrophobic pocket, a possible strategy for targeting viral particle assembly. 相似文献
154.
Anthony Prandina Sylvie Radix Marc Le Borgne Lars Petter Jordheim Zineb Bousfiha Christopher Fröhlich Hanna-Kirsti S. Leiros Ørjan Samuelsen Espen Frøvold Pål Rongved Ove Alexander Høgmoen Åstrand 《Tetrahedron》2019,75(11):1525-1540
Antibiotics are key drugs in modern healthcare, especially in hospitals, where multiresistant bacteria resides and is a potential threat to human health. In the present work, a new series of adjuvants working synergistically with the carbapenem meropenem, in which a selective zinc-chelating agent was covalently linked to the small bacterial peptide D-Ala-D-Ala, was synthesized and tested against VIM-2 and NDM-1 metallo-β-lactamases (MBLs). The nature of the linker was modified in a structure-activity relationship study. Compound 1i, having an ethyl piperidine linker, lowered the MIC of meropenem from 32 to 64?mg/L to 2 and 1–2?mg/L against VIM-2- and NDM-1-producing clinical isolates, respectively. The IC50 value of 1i against VIM-2 was 9.8 and 2.2?μM after 5 and 20?min, respectively. Compound 1i also showed intrinsic toxicity against three eukaryotic human tumoral cell lines between 50 and 120?μM. 相似文献
155.
156.
157.
Sylvie Griener-Guillod 《Commentarii Mathematici Helvetici》1988,63(1):48-74
Résumé Dans cet article, nous étudions la maximalité de certains sous-groupes de l’ensemble des éléments inversibles (ou unitaires)
d’uneC
*-algèbre ou d’un facteur. 相似文献
158.
Summary We study the chaos hypothesis for a wide class of pure-jump multitype interacting systems. The interaction may be strong, there is no symmetry assumption, and the system is not necessarily Markovian. We use interaction graphs and coupling and study in a precise way how a chain reaction is constituted by a series of direct interactions. We obtain the chaos hypothesis in variation norm with speed of convergence and deduce from it convergence of general empirical measures. We couple the interaction graph to a Boltzmann tree and show that the variation norm between the processes constructed on each goes to zero. This proves propagation of chaos in total variation with speed of convergence when the Boltzmann trees converge. Under light symmetry assumptions, we characterize the limit law by a nonlinear martingale problem.We dedicate this paper to Professor Claude Kipnis, who brought these network problems to our attention.URA CNRS 756URA CNRS 224This article was processed by the author using the Springer-Verlag TEX QPMZGHB macro package 1991. 相似文献
159.
Sylvie Monniaux Jan Prü ss 《Transactions of the American Mathematical Society》1997,349(12):4787-4814
A theorem of the Dore-Venni type for the sum of two closed linear operators is proved, where the operators are noncommuting but instead satisfy a certain commutator condition. This result is then applied to obtain optimal regularity results for parabolic evolution equations and evolutionary integral equations which are nonautonomous. The domains of the involved operators may depend on , but is required to satisfy a certain smoothness property. The results are then applied to parabolic partial differential and integro-differential equations.
160.
Fibrin, the biopolymer produced in the final step of the coagulation cascade, is involved in the resistance of arterial thrombi to fragmentation under shear flow. However, the nature and strength of specific interactions between fibrin monomers are unknown. Thus, the shear-induced detachment of spherical monodispersed fibrin-coated latex particles in adhesive contact with a plane fibrin-coated glass surface has been experimentally studied, using an especially designed shear stress flow chamber. A complete series of experiments for measuring the shear stress necessary to release individual particles under various conditions (various number of fibrin layers involved in the adhesive contact, absence or presence of plasmin, the main physiological fibrinolytic enzyme) has been performed. The nonspecific DLVO interactions have been shown to be negligible compared to the interactions between fibrin monomers. A simple adhesion model based on the balance of forces and torque on particles, assuming an elastic behavior of the fibrin polymer bonds, to analyze the experimental data in terms of elastic force at rupture of an elementary intermonomeric fibrin bond has been used. The results suggested that this force (of order 400 pN) is an intrinsic quantity, independent of the number of fibrin layers involved in the adhesive contact. Copyright 2001 Academic Press. 相似文献