全文获取类型
收费全文 | 186篇 |
免费 | 7篇 |
专业分类
化学 | 101篇 |
晶体学 | 1篇 |
力学 | 8篇 |
数学 | 53篇 |
物理学 | 30篇 |
出版年
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 4篇 |
2017年 | 7篇 |
2016年 | 4篇 |
2015年 | 1篇 |
2014年 | 10篇 |
2013年 | 9篇 |
2012年 | 14篇 |
2011年 | 15篇 |
2010年 | 8篇 |
2009年 | 13篇 |
2008年 | 14篇 |
2007年 | 18篇 |
2006年 | 10篇 |
2005年 | 12篇 |
2004年 | 11篇 |
2003年 | 8篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1997年 | 1篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 2篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1979年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有193条查询结果,搜索用时 15 毫秒
31.
Runyon MK Kastrup CJ Johnson-Kerner BL Ha TG Ismagilov RF 《Journal of the American Chemical Society》2008,130(11):3458-3464
This paper describes microfluidic experiments with human blood plasma and numerical simulations to determine the role of fluid flow in the regulation of propagation of blood clotting. We demonstrate that propagation of clotting can be regulated by different mechanisms depending on the volume-to-surface ratio of a channel. In small channels, propagation of clotting can be prevented by surface-bound inhibitors of clotting present on vessel walls. In large channels, where surface-bound inhibitors are ineffective, propagation of clotting can be prevented by a shear rate above a threshold value, in agreement with predictions of a simple reaction-diffusion mechanism. We also demonstrate that propagation of clotting in a channel with a large volume-to-surface ratio and a shear rate below a threshold shear rate can be slowed by decreasing the production of thrombin, an activator of clotting. These in vitro results make two predictions, which should be experimentally tested in vivo. First, propagation of clotting from superficial veins to deep veins may be regulated by shear rate, which might explain the correlation between superficial thrombosis and the development of deep vein thrombosis (DVT). Second, nontoxic thrombin inhibitors with high binding affinities could be locally administered to prevent recurrent thrombosis after a clot has been removed. In addition, these results demonstrate the utility of simplified mechanisms and microfluidics for generating and testing predictions about the dynamics of complex biochemical networks. 相似文献
32.
33.
34.
Valiullin R Dvoyashkin M Kortunov P Krause C Kärger J 《The Journal of chemical physics》2007,126(5):054705
The pulsed field gradient nuclear magnetic resonance method has been used to study self-diffusion of cyclohexane in a commercial MCM-41 material at different external gas pressures from zero to saturated vapor pressure. It is found that the effective diffusivities exhibit three different regions with increasing pressure: decrease at low pressures, a sudden drop at intermediate pressures, and increase at higher pressures. In addition, in the region of irreversible adsorption (hysteresis loop) the diffusivities are also found to differ on the adsorption and the desorption branches. A simple analytical model taking account of different molecular ensembles with different transport properties due to the complex architecture of the porous structure is developed which provides a quantitative prediction of the experimental data. The analysis reveals that the effective diffusivity is predominantly controlled by the adsorption properties of the individual mesoporous MCM-41 crystallites which, in combination with high transport rates, provide a simple instrument for fine tuning of the transport properties by a subtle variation of the external conditions. 相似文献
35.
36.
Kamzin A. S. Valiullin A. A. Semenov V. G. Das Harinarayan Wakiya Naoki 《Physics of the Solid State》2019,61(6):1113-1121
Physics of the Solid State - We present the data of studies on the structure, phase states, and magnetic properties of magnetic nanoparticles (MNPs) of magnesium ferrite spinel (MgFe2O4),... 相似文献
37.
E. K. Sadykov A. A. Yurichuk F. G. Vagizov Sh. I. Mubarakshin A. A. Valiullin 《Hyperfine Interactions》2017,238(1):85
A new model of Mössbauer absorption (transmission) spectra with an adequate analysis of the possible effects of acoustic excitation in the thick targets is proposed. In particular, the dependence of the line width of acoustical satellites on the degree of phase correlation of the sound oscillations of resonant nuclei in the target is established by calculations and confirmed in experiment. Such a model is stimulated by an increase in the informativeness of the Mössbauer experiments, using thick samples in ultrasound (US) field, and by possible applications of this research technique. The test measurements of Mössbauer absorption spectra on stainless steel are carried out. The fitting of these spectra confirms the relevance of modifications of the model base of Mössbauer processes in US field. 相似文献
38.
Matthias Meier Dr. Julia Kennedy‐Darling Se Hoon Choi Eric M. Norstrom Dr. Sangram S. Sisodia Prof. Dr. Rustem F. Ismagilov Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(8):1487-1489
Small with control : For miniaturization of protein aggregation experiments the interfacial chemistry must be controlled to avoid protein aggregation caused by interfacial adsorption. Plug‐based microfluidics with defined surface chemistry (see schematic picture) can then be used to perform hundreds of aggregation experiments with volume‐limited samples, such as cerebrospinal fluid from mice.
39.
We propose an algorithm for the global optimization of continuous minimax problems involving polynomials. The method can be
described as a discretization approach to the well known semi-infinite formulation of the problem. We proceed by approximating
the infinite number of constraints using tools and techniques from semidefinite programming. We then show that, under appropriate
conditions, the SDP approximation converges to the globally optimal solution of the problem. We also discuss the numerical
performance of the method on some test problems.
Financial support of EPSRC Grant GR/T02560/01 gratefully acknowledged. 相似文献
40.
P. Parpas B. Rustem V. Wieland S. Žaković 《Computational Optimization and Applications》2009,43(2):235-259
In this paper, we consider expected value, variance and worst–case optimization of nonlinear models. We present algorithms
for computing optimal expected value, and variance policies, based on iterative Taylor expansions. We establish convergence
and consider the relative merits of policies based on expected value optimization and worst–case robustness. The latter is
a minimax strategy and ensures optimal cover in view of the worst–case scenario(s) while the former is optimal expected performance
in a stochastic setting.
Both approaches are used with a small macroeconomic model to illustrate relative performance, robustness and trade-offs between
the alternative policies. 相似文献