全文获取类型
收费全文 | 82篇 |
免费 | 5篇 |
专业分类
化学 | 49篇 |
力学 | 2篇 |
数学 | 17篇 |
物理学 | 19篇 |
出版年
2022年 | 3篇 |
2020年 | 2篇 |
2018年 | 3篇 |
2017年 | 1篇 |
2016年 | 4篇 |
2015年 | 3篇 |
2014年 | 1篇 |
2013年 | 4篇 |
2012年 | 1篇 |
2011年 | 3篇 |
2010年 | 4篇 |
2008年 | 4篇 |
2007年 | 5篇 |
2006年 | 2篇 |
2005年 | 3篇 |
2004年 | 5篇 |
2003年 | 5篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1980年 | 1篇 |
1976年 | 4篇 |
1972年 | 1篇 |
1969年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有87条查询结果,搜索用时 359 毫秒
61.
We study the long-time asymptotics of linear kinetic models with periodic boundary conditions or in a rectangular box with specular reflection boundary conditions. An entropy dissipation approach is used to prove decay to the global equilibrium under some additional assumptions on the equilibrium distribution of the mass preserving scattering operator. We prove convergence at an algebraic rate depending on the smoothness of the solution. This result is compared to the optimal result derived by spectral methods in a simple one dimensional example. 相似文献
62.
Klemens Fellner Frederic Poupaud Christian Schmeiser 《Journal of statistical physics》2004,114(5-6):1481-1499
A kinetic equation with a relaxation time model for wave-particle collisions is considered. Similarly to the BGK-model of gas dynamics, it involves a projection onto the set of equilibrium distributions, nonlinearly dependent on moments of the distribution function. An earlier existence result is extended to bounded domains with reflecting boundaries and to initial conditions permitting vacuum regions. The long time behaviour is investigated. Convergence on compact time intervals (shifted to infinity) to the set of equilibrium solutions is proven. The set of smooth equilibrium solutions is computed. 相似文献
63.
Bao Y Guérout R Lussange J Lambrecht A Cirelli RA Klemens F Mansfield WM Pai CS Chan HB 《Physical review letters》2010,105(25):250402
We measure the Casimir force between a gold sphere and a silicon plate with nanoscale, rectangular corrugations with a depth comparable to the separation between the surfaces. In the proximity force approximation (PFA), both the top and bottom surfaces of the corrugations contribute to the force, leading to a distance dependence that is distinct from a flat surface. The measured Casimir force is found to deviate from the PFA by up to 10%, in good agreement with calculations based on scattering theory that includes both geometry effects and the optical properties of the material. 相似文献
64.
65.
Controlling the phase delay of light transmitted through double-layer metallic subwavelength slit arrays 总被引:1,自引:0,他引:1
Marcet Z Paster JW Carr DW Bower JE Cirelli RA Klemens F Mansfield WM Miner JF Pai CS Chan HB 《Optics letters》2008,33(13):1410-1412
We demonstrate that the phase of light transmitted through double-layer subwavelength metallic slit arrays can be controlled through lateral shift of the two layers. Our samples consist of two aluminum layers, each of which contains an array of subwavelength slits. The two layers are placed in sufficient proximity to allow coupling of the evanescent fields at resonance. By changing the lateral shift between the layers from zero to half the period, the phase of the transmitted electromagnetic field is increased by pi, while the transmitted intensity remains high. Such a controllable phase delay could open new capabilities for nanophotonic devices that cannot be achieved with single-layer structures. 相似文献
66.
67.
68.
Klemens Döpp 《Archive for Mathematical Logic》1969,12(1-2):66-71
Ohne Zusammenfassung 相似文献
69.
Pranzas PK Knöchel A Kneifel K Kamusewitz H Weigel T Gehrke R Funari SS Willumeit R 《Analytical and bioanalytical chemistry》2003,376(5):602-607
Polymeric membranes are used in industrial and analytical separation techniques. In this study small-angle X-ray scattering (SAXS) with synchrotron radiation has been applied for in-situ characterisation during formation of polymeric membranes. The spinning of a polyetherimide (PEI) hollow fibre membrane was chosen for investigation of dynamic aggregation processes during membrane formation, because it allows the measurement of the dynamic equilibrium at different distances from the spinning nozzle. With this system it is possible to resolve structural changes in the nm-size range which occur during membrane formation on the time-scale of milliseconds. Integral structural parameters, like radius of gyration and pair-distance distribution, were determined. Depending on the chosen spinning parameters, e.g. the flow ratio between polymer solution and coagulant water, significant changes in the scattering curves have been observed. The data are correlated with the distance from the spinning nozzle in order to get information about the kinetics of membrane formation which has fundamental influence on structure and properties of the membrane. 相似文献
70.
The System Gd/Co/B: Preparation and Characterization by X‐ray Diffraction of GdCo4B, Gd3Co11B4, GdCoB4, and GdCo12B6 The compounds GdCo4B, Gd3Co11B4, GdCoB4, and GdCo12B6 were characterized by X‐ray investigations of single crystals. GdCo4B (P 6/mmm, a = 505.9(1) pm, c = 690.1(1) pm) crystallizes with the CeCo4B structure type; Gd3Co11B4 (P 6/mmm, a = 508.7(1) pm, c = 982.9(9) pm) with the Ce3Co11B4 stucture type; GdCo12B6 ( , a = 949.5(1) pm, c = 747.4(1) pm) with the SrNi12B6 structure type and GdCoB4 (P bam, a = 591.3(9) pm, b = 1145.1(6) pm, c = 346.2(3) pm) with the YbCoB4 structure type. 相似文献