全文获取类型
收费全文 | 430篇 |
免费 | 17篇 |
国内免费 | 1篇 |
专业分类
化学 | 311篇 |
晶体学 | 2篇 |
力学 | 14篇 |
数学 | 27篇 |
物理学 | 94篇 |
出版年
2021年 | 8篇 |
2020年 | 5篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2016年 | 12篇 |
2015年 | 12篇 |
2014年 | 7篇 |
2013年 | 23篇 |
2012年 | 23篇 |
2011年 | 23篇 |
2010年 | 12篇 |
2009年 | 17篇 |
2008年 | 22篇 |
2007年 | 24篇 |
2006年 | 23篇 |
2005年 | 21篇 |
2004年 | 13篇 |
2003年 | 16篇 |
2002年 | 19篇 |
2001年 | 3篇 |
2000年 | 9篇 |
1999年 | 10篇 |
1998年 | 8篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1990年 | 12篇 |
1989年 | 3篇 |
1986年 | 3篇 |
1985年 | 12篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1977年 | 5篇 |
1976年 | 6篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1969年 | 3篇 |
1938年 | 2篇 |
1928年 | 2篇 |
1866年 | 2篇 |
排序方式: 共有448条查询结果,搜索用时 843 毫秒
81.
Luisa Silva Thierry Coupez Hugues Digonnet 《International Journal of Computational Fluid Dynamics》2016,30(6):431-436
ABSTRACTIn this paper, a work performed to allow massively parallel finite element flow computations is presented. It includes the development and optimisation of two particular features of a finite element multiphase computational fluid dynamics software, which are mesh generation and linear system solution, using anisotropic adaptation and multigrid preconditioning. Parallel performances on supercomputers are shown, where the largest generated mesh (on 65 536 Intel Xeon or 261 144 Power PC cores) had 33.4 billions of nodes, leading to a 100 billion of unknowns linear system solution. Final applications concern, between others, image-based flow simulations. 相似文献
82.
Dr. Mariusz Tasior Vincent Hugues Dr. Mireille Blanchard‐Desce Prof. Daniel T. Gryko 《化学:亚洲杂志》2012,7(11):2656-2661
New, strongly fluorescent benzo[1,2‐d:4,5‐d′]bisimidazoles have been prepared by the reaction of Bandrowski′s base with various aldehydes. Their structures were carefully designed to achieve efficient excited‐state intramolecular proton transfer and good two‐photon‐absorption (2PA) cross‐sections. Functional dyes that possessed both high fluorescence quantum yields and large Stokes shifts were prepared. A π‐expanded D‐A‐D derivative that possessed Φfl=50 % and σ2=230 GM in the spectroscopic area of interest for biological imaging is an excellent candidate as a fluorescent probe. Thanks to the presence of two reactive amino groups, such compounds can be easily transformed into probes for bioconjugation. All of these benzo[1,2‐d:4,5‐d′]bisimidazoles were also strongly fluorescent in the solid state. 相似文献
83.
84.
Vronique Rouchon Hugues Badet Oulfa Belhadj Olivier Bonnerot Bertrand Lavdrine Jean‐Guy Michard Serge Miska 《Journal of Raman spectroscopy : JRS》2012,43(9):1265-1274
Fossil materials that contain iron sulfide are well known for their instability when exposed to oxygen and humidity. This term however combines a great variety of materials showing different types of damages. Most of them consist of crystal efflorescence appearing on the surface and inside the matrix. In this work, a methodology was determined for the analysis of these damages by the use of Raman and infrared spectroscopy. The infrared and Raman signatures of a large set of iron sulfates were characterized. Specific attention was paid to sideronatrite and ferrinatrite, which are two associated sodium/iron(III) sulfates, and their infrared and Raman bands were partially assigned. Analysis performed on a selection of 11 damaged fossils showed a great variety of degradation products: besides one case that appeared to be a synthetic resin close to polyvinylchloride acetate, which was applied with a brush on the fossil surface, all degradation products belong to the sulfate group. However, many iron‐free sulfates, such as gypsum, halotrichite, epsomite, or pentahydrite were found, often in association with iron sulfates. In one case, despite the presence of iron in the matrix, no iron sulfate could be detected. This shows that the term ‘pyritic fossil’, commonly used by collection managers, is not appropriate as it oversimplifies the reality. A name such as ‘sulfide‐containing fossil’ would be more suitable. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
85.
L. Audirac P. Ascher B. Blank C. Borcea B. A. Brown G. Canchel C. E. Demonchy F. de Oliveira Santos C. Dossat J. Giovinazzo S. Grévy L. Hay J. Huikari S. Leblanc I. Matea J. -L. Pedroza L. Perrot J. Pibernat L. Serani C. Stodel J. -C. Thomas 《The European Physical Journal A - Hadrons and Nuclei》2012,48(12):1-12
The two-proton radioactivity of 45Fe was studied experimentally with a time projection chamber. The aim of the experiment was the reconstruction of the proton tracks in three dimensions. Energy and angular correlations have been determined and the data are compared with theoretical models, in particular with a three-body model. Moreover, the decay of 43Cr was studied and ??-delayed one-, two- and three-proton emission could be established. The correlations observed for ??-delayed two-proton emission favour a sequential emission. Finally, ??-delayed two-proton emission was observed for the first time for 51Ni. 相似文献
86.
Yahia Didane Rocio Ponce Ortiz Jian Zhang Keijyu Aosawa Toshinori Tanisawa Hecham Aboubakr Frédéric Fages Jörg Ackermann Noriyuki Yoshimoto Hugues Brisset Christine Videlot-Ackermann 《Tetrahedron》2012,68(24):4664-4671
Solution and solid-state properties of two new perfluoroalkyl end-substituted analogues of distyryl-bithiophene (CF3-DS2T and diCF3-DS2T) are presented. Vacuum deposited thin films were investigated by atomic force microscopy, X-ray diffraction, and implemented as active layers into organic thin film transistors. While physicochemical measurements in solution suggest a preferential hole injection and transport inside CF3-DS2T and diCF3-DS2T films, electrical measurements performed under high vacuum show that CF3-DS2T behaves as n-type semiconductor while no charge transport was measured in diCF3-DS2T. The results highlighted the importance of substituents on conjugated backbone and on the resulting fine ordering in solid state to control the charge transport. 相似文献
87.
Connell BJ Baleux F Coic YM Clayette P Bonnaffé D Lortat-Jacob H 《Chemistry & biology》2012,19(1):131-139
The HIV-1 envelope gp120, which features both the virus receptor (CD4) and coreceptor (CCR5/CXCR4) binding sites, offers multiple sites for therapeutic intervention. However, the latter becomes exposed, thus vulnerable to inhibition, only transiently when the virus has already bound cellular CD4. To pierce this defense mechanism, we engineered a series of heparan sulfate mimicking tridecapeptides and showed that one of them target the gp120 coreceptor binding site with μM affinity. Covalently linked to a CD4-mimetic that binds to gp120 and renders the coreceptor binding domain available to be targeted, the conjugated tridecapeptide now displays nanomolar affinity for its target. Using solubilized coreceptors captured on top of sensorchip we show that it inhibits gp120 binding to both CCR5 and CXCR4 and in peripheral blood mononuclear cells broadly inhibits HIV-1 replication with an IC(50) of 1 nM. 相似文献
88.
Hugues Verdure 《Archiv der Mathematik》2006,86(2):121-128
We give a simple criterion for the cyclicity of the m-torsion subgroup of the group of rational points on an elliptic curve defined over a finite field of characteristic larger
than 3 for m = 2, 3, 4, 6, 12.
Received: 25 January 2005 相似文献
89.
90.