全文获取类型
收费全文 | 926篇 |
免费 | 39篇 |
国内免费 | 2篇 |
专业分类
化学 | 654篇 |
晶体学 | 1篇 |
力学 | 13篇 |
数学 | 186篇 |
物理学 | 113篇 |
出版年
2023年 | 9篇 |
2022年 | 9篇 |
2021年 | 10篇 |
2020年 | 25篇 |
2019年 | 25篇 |
2018年 | 9篇 |
2017年 | 12篇 |
2016年 | 34篇 |
2015年 | 29篇 |
2014年 | 27篇 |
2013年 | 36篇 |
2012年 | 50篇 |
2011年 | 53篇 |
2010年 | 35篇 |
2009年 | 37篇 |
2008年 | 62篇 |
2007年 | 65篇 |
2006年 | 51篇 |
2005年 | 60篇 |
2004年 | 40篇 |
2003年 | 48篇 |
2002年 | 31篇 |
2001年 | 20篇 |
2000年 | 27篇 |
1999年 | 20篇 |
1998年 | 13篇 |
1997年 | 13篇 |
1996年 | 11篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 7篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1979年 | 4篇 |
1977年 | 4篇 |
1976年 | 7篇 |
1969年 | 4篇 |
1968年 | 3篇 |
1962年 | 3篇 |
1961年 | 2篇 |
1960年 | 2篇 |
1920年 | 2篇 |
排序方式: 共有967条查询结果,搜索用时 562 毫秒
111.
Aijun Li Olaf Deutschmann Romana Piat Thomas Böhlke Igor Tsukrov Todd Gross 《PAMM》2010,10(1):715-716
A conserved phase-field model is proposed to investigate the effect of interfacial energy on the morphological evolution of the pyrolytic carbon deposit in chemical vapor deposition. The equilibrium geometry of carbon deposit islands is analytically predicted, of which the contact angle was controlled through the boundary conditions of the phase-field parameter at the substrate surface according to the Young-Laplace equation. Simulations of deposit growth are carried out for single and multi island nucleation. It is clarified that the island morphology depends on the magnitude of the interface energy. It is also observed that high interface energy results in large island size fluctuation. (© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
112.
In order to reduce the numerical cost of three dimensional flow problems with geometrical symmetry, the use of symmetric boundary conditions is standard. For Newtonian fluid flow problems this approximation is usually appropriate, particularly when the Reynolds number is small. In the case of viscoelastic fluid flow simulations with stabilization techniques, such as the so-called DEVSS and/or Log-Conformation tensor methods, at high Deborah number flows this implementation is not straightforward, as in the Newtonian case. It is well known that viscoelastic models (e.g. Maxwellian models), show (purely) elastic flow instabilities when the Deborah number is increased above a critical value, even under creeping flow conditions. In this work we present numerical simulations with different stabilization techniques and different differential viscoelastic models at high Deborah number flows. As a test-case, we compare the flow in a full two-dimensional cross-slot geometry to show the asymmetrical behavior of the viscoelastic fluid flow. (© 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
113.
Kristina O. Kvashnina Anna Yu. Romanchuk Ivan Pidchenko Lucia Amidani Evgeny Gerber Alexander Trigub Andre Rossberg Stephan Weiss Karin Popa Olaf Walter Roberto Caciuffo Andreas C. Scheinost Sergei M. Butorin Stepan N. Kalmykov 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(49):18044-18044
114.
Andrei Hutanu Steffen Kiessig Andrea Bathke Rolf Ketterer Sonja Riner Jan Olaf Stracke Markus Wild Bernd Moritz 《Electrophoresis》2019,40(22):3014-3022
Charge heterogeneity profiling is important for the quality control (QC) of biopharmaceuticals. Because of the increasing complexity of these therapeutic entities [1], the development of alternative analytical techniques is needed. In this work, flow‐through partial‐filling affinity capillary electrophoresis (FTPFACE) has been established as a method for the analysis of a mixture of two similar monoclonal antibodies (mAbs). The addition of a specific ligand results in the complexation of one mAb in the co‐formulation, thus changing its migration time in the electric field. This allows the characterization of the charged variants of the non‐shifted mAb without interferences. Adsorption of proteins to the inner capillary wall has been circumvented by rinsing with guanidine hydrochloride before each injection. The presented FTPFACE approach requires only very small amounts of ligands and provides complete comparability with a standard CZE of a single mAb. 相似文献
115.
Abeer Alghamdi Thorben Wellbrock Prof. David J. S. Birch Dr. Vladislav Vyshemirsky Dr. Olaf J. Rolinski 《Chemphyschem》2019,20(23):3181-3185
A non-invasive intrinsic fluorescence sensing of the early stages of Alzheimer's beta amyloid peptide aggregation in the presence of copper ions is reported. By using time-resolved fluorescence techniques the formation of beta amyloid-copper complexes and the accelerated peptide aggregation are demonstrated. The shifts in the emission spectral peaks indicate that the peptides exhibit different aggregation pathways than in the absence of copper. 相似文献
116.
We consider Euclidean SU(N) Yang–Mills theory on the space G×R, where G is a compact semisimple Lie group, and introduce first-order BPS-type equations which imply the full Yang–Mills equations. For gauge fields invariant under the adjoint G -action these BPS equations reduce to first-order matrix equations, to which we give instanton solutions. In the case of G=SU(2)≅S3, our matrix equations are recast as Nahm equations, and a further algebraic reduction to the Toda chain equations is presented and solved for the SU(3) example. Finally, we change the metric on G×R to Minkowski and construct finite-energy dyon-type Yang–Mills solutions. The special case of G=SU(2)×SU(2) may be used in heterotic flux compactifications. 相似文献
117.
Vishnu Vardhan Krishnamachari Eric Olaf Potma 《Journal of Raman spectroscopy : JRS》2008,39(5):593-598
Focus‐engineered coherent anti‐Stokes Raman scattering (FE‐CARS) microscopy is used to highlight the lateral interfaces between chemically distinct media. Interface highlighting is achieved by using a HG10 mode for the Stokes laser beam and a HG00 mode for the pump laser beam in the forward detection scheme. The spectral and the orientation dependence of FE‐CARS are found to be in agreement with theoretical predictions. A brief discussion on the relevance of this technique for imaging third‐order nonlinear susceptibility interfaces in thin samples of biological or chemical importance is presented. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
118.
119.
Prof. Olaf M. Magnussen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(56):12865-12883
Atomic-scale processes at electrode surfaces in liquid electrolytes are central elemental steps of electrochemical reactions. Detailed insights into the structure of these interfaces can be obtained with in situ scanning tunnelling and atomic force microscopy. By increasing the time resolution of these methods into the millisecond range, highly dynamic processes at electrode surfaces become directly observable. This review gives an overview of in situ studies with video-rate scanning probe microscopy techniques. Firstly, quantitative investigations into the dynamic behaviour of individual adsorbed atoms and molecules are described. These reveal a complex dependence of adsorbate surface diffusion on potential and co-adsorbed species and provide data on adsorbate–adsorbate and adsorbate–substrate interactions in a liquid environment. Secondly, results on collective dynamic phenomena are discussed, such as molecular self-assembly, the dynamics of nanoscale structures, nucleation and growth, and surface restructuring due to phase-formation processes. 相似文献
120.
Conrad Wagner Franka Kreis Dennis Popp Dr. Olaf Hübner Dr. Elisabeth Kaifer Prof. Hans-Jörg Himmel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(45):10336-10347
In this work, the change of reactivity induced by the introduction of two para-ethynyl substituents (CCSi(iPr)3 or CCH) to the organic electron-donor 1,2,4,5-tetrakis(tetramethylguanidino)-benzene is evaluated. The redox-properties and redox-state dependent fluorescence are evaluated, and dinuclear CuI and CuII complexes synthesized. The Lewis-acidic B(C6F5)3 substitutes the proton of the ethynyl −CCH groups to give new anionic −CCB(C6F5)3− substituents, leading eventually to a novel dianionic strong electron donor in its diprotonated form. Its two-electron oxidation with dioxygen in the presence of a copper catalyst yields the first redox-active guanidine that is neutral (instead of cationic) in its oxidized form. 相似文献