全文获取类型
收费全文 | 193篇 |
免费 | 11篇 |
专业分类
化学 | 111篇 |
晶体学 | 2篇 |
力学 | 35篇 |
数学 | 25篇 |
物理学 | 31篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 7篇 |
2021年 | 7篇 |
2020年 | 2篇 |
2019年 | 6篇 |
2018年 | 9篇 |
2017年 | 8篇 |
2016年 | 8篇 |
2015年 | 7篇 |
2014年 | 7篇 |
2013年 | 7篇 |
2012年 | 16篇 |
2011年 | 21篇 |
2010年 | 15篇 |
2009年 | 19篇 |
2008年 | 10篇 |
2007年 | 10篇 |
2006年 | 4篇 |
2005年 | 2篇 |
2004年 | 5篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1995年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1983年 | 4篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
排序方式: 共有204条查询结果,搜索用时 31 毫秒
81.
82.
M. Nazar Corina Fetecau D. Vieru C. Fetecau 《Nonlinear Analysis: Real World Applications》2010,11(1):584-591
New exact solutions for the velocity field corresponding to the second problem of Stokes, for second grade fluids, have been established by the Laplace transform method. These solutions, presented as a sum of the steady-state and transient solutions, are in accordance with the previous solutions obtained by a different technique. The required time to reach the steady state is determined by graphical illustrations. This time decreases if the frequency of the velocity increases. The effects of the material parameters on the decay of the transients are also investigated by graphs. 相似文献
83.
Nazar Manko Marina Starykovych Yaroslav Bobak Rostyslav Stoika Vladimir Richter Olga Koval Inna Lavrik Daniel Hork Serhiy Souchelnytskyi Yuriy Kit 《Biomedical chromatography : BMC》2019,33(11)
The cytopoxic effect of RL2 lactaptin (the recombinant analog of proteolytic fragment of human kappa‐casein) toward tumor cells in vitro and in vivo presents it as a novel promising antitumor drug. The binding of any drug with serum proteins can affect their activity, distribution, rate of excretion and toxicity in the human body. Here, we studied the ability of RL2 to bind to various blood serum proteins. Using magnetic microparticles bearing by RL2 as an affinity matrix, in combination with mass spectrometry and western blot analysis, we found a number of blood serum proteins possessing affinity for RL2. Among them IgA, IgM and IgG subclasses of immunoglobulins, apolipoprotein A1 and various cortactin isoforms were identified. This data suggests that in the bloodstream RL2 lactaptin takes part in complicate protein–protein interactions, which can affect its activity. 相似文献
84.
The steady laminar boundary layer flow and heat transfer from a warm, laminar liquid flow to a melting surface moving parallel
to a constant free stream is studied in this paper. The continuity, momentum and energy equations, which are coupled nonlinear
partial differential equations are reduced to a set of two nonlinear ordinary differential equations, before being solved
numerically using the Runge–Kutta–Fehlberg method. Results for the skin friction coefficient, local Nusselt number, velocity
profiles as well as temperature profiles are presented for different values of the governing parameters. Effects of the melting
parameter, moving parameter and Prandtl number on the flow and heat transfer characteristics are thoroughly examined. It is
found that the problem admits dual solutions. 相似文献
85.
The unsteady laminar flow of an incompressible micropolar fluid over a stretching sheet is investigated. The unsteadiness
in the flow and temperature fields is caused by the time-dependence of the stretching velocity and the surface temperature.
Effects of the unsteadiness parameter, material parameter and Prandtl number on the flow and heat transfer characteristics
are thoroughly examined. 相似文献
86.
Waqar Azeem Peter John Muhammad Faizan Nazar Muhammad Ashfaq Islam Ullah Khan Shahzad Sharif Atif Riaz 《Journal of solution chemistry》2018,47(6):1048-1059
Core–shell architecture of surfactant micelles can act to shield active drug molecules from the adverse environmental conditions and enhance their bioavailability. In the present study the molecular interactions of a fixed dose combination (FDC) containing ofloxacin (OFX) and ornidazole (ORN), with cetyltrimethylammonium bromide (CTAB, a quaternary ammonium surfactant) were investigated under normal physiological pH (pH 7.4?±?0.1). The impact of the cationic micelle on the spectral and physiochemical properties of the FDC components OFX and ORN was systematically examined by electronic spectroscopy. Micellar liquid chromatography and differential spectral methods were used to optimize analysis of the magnitude of binding constants and related Gibbs energies. The results suggest the potential solubilization of drugs in the external part of the micelles, which may prove to be more helpful for their controlled release. These outcomes have been verified by the binding capacities of drug–CTAB combinational system that may be helpful to customize the uptake of drug molecules in cells. 相似文献
87.
88.
A heterogeneous polyvinylpolypyrrolidone supported Brønsted acidic catalyst ([PVPP-BS]HSO4) was used to synthesize butyrate in this paper. The prepared catalysts were characterized by FT-IR, TG, and FESEM and their catalytic activity in butyric acid esterification with benzyl alcohol was investigated. The influencing factors such as the amount of catalyst, reaction temperature, and reaction time were carefully studied. Under the optimized condition with the butyric acid to benzyl alcohol mole ratio of 1: 1.2 and the reaction temperature of 130°C, the yield of benzyl butyrate reached 96.8 % within 4 h in the presence of 8 mass % of catalyst. Moreover, the catalyst could be reused six times without noticeable drop in activity. This catalyst was also used to synthesize other kinds of butyrates achieving the butyrate yield above 90 %. 相似文献
89.
90.
Research on Chemical Intermediates - In this work, montmorillonite (MMT), as an anti-settling agent, was added to modified waterborne potassium silicate zinc-rich coating (MWPC), aiming at... 相似文献