全文获取类型
收费全文 | 933篇 |
免费 | 42篇 |
国内免费 | 7篇 |
专业分类
化学 | 610篇 |
晶体学 | 12篇 |
力学 | 36篇 |
综合类 | 1篇 |
数学 | 88篇 |
物理学 | 235篇 |
出版年
2023年 | 7篇 |
2022年 | 25篇 |
2021年 | 27篇 |
2020年 | 23篇 |
2019年 | 25篇 |
2018年 | 23篇 |
2017年 | 14篇 |
2016年 | 37篇 |
2015年 | 27篇 |
2014年 | 51篇 |
2013年 | 79篇 |
2012年 | 76篇 |
2011年 | 81篇 |
2010年 | 39篇 |
2009年 | 39篇 |
2008年 | 47篇 |
2007年 | 45篇 |
2006年 | 59篇 |
2005年 | 40篇 |
2004年 | 31篇 |
2003年 | 26篇 |
2002年 | 30篇 |
2001年 | 30篇 |
2000年 | 19篇 |
1999年 | 8篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1988年 | 3篇 |
1987年 | 7篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1984年 | 7篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1972年 | 1篇 |
1967年 | 1篇 |
1965年 | 1篇 |
1917年 | 1篇 |
1911年 | 2篇 |
排序方式: 共有982条查询结果,搜索用时 375 毫秒
31.
32.
Gitae Moon Intae Son Chunho Kim Chi Hyeong Cho Eunbi Lee Eun Hyoung Bae 《Molecular Crystals and Liquid Crystals》2019,687(1):60-67
AbstractTo enable recent 3D and moving picture applications, liquid crystal displays (LCD) must exhibit fast response and wide viewing angle characteristics. Pre-tilted vertical alignment layers for high-speed LCD were fabricated using bi-functional photoreactive monomers. The monomers can be confined to the polyimide layer and photo-polymerized by UV exposure under voltage. Response characteristics of photo-controlled alignment films according to the structure were investigated. Vertical alignment properties were evaluated using a polarizing optical microscope, and electro-optical characteristics were compared through the voltage-transmittance curve and response time measurement. Faster response speed could be obtained by using photoreactive monomers having a long alkyl chain. 相似文献
33.
Son Tung Dang Ernst Arne Meese John Christian Morud Stein Tore Johansen 《国际流体数值方法杂志》2019,91(9):419-447
In this paper, we introduce numerical methods that can simulate complex multiphase flows. The finite volume method, applying Cartesian cut-cell is used in the computational domain, containing fluid and solid, to conserve mass and momentum. With this method, flows in and around any geometry can be simulated without complex and time consuming meshing. For the fluid region, which involves liquid and gas, the ghost fluid method is employed to handle the stiffness of the interface discontinuity problem. The interaction between each phase is treated simply by wall function models or jump conditions of pressure, velocity and shear stress at the interface. The sharp interface method “coupled level set (LS) and volume of fluid (VOF)” is used to represent the interface between the two fluid phases. This approach will combine some advantages of both interface tracking/capturing methods, such as the excellent mass conservation from the VOF method and good accuracy of interface normal computation from the LS function. The first coupled LS and VOF will be generated to reconstruct the interface between solid and the other materials. The second will represent the interface between liquid and gas. 相似文献
34.
Tran Thu Ha Nguyen Hong Phong François-Xavier Le Dimet Hong Son Hoang 《Comptes Rendus Mecanique》2019,347(5):423-444
This article presents a correction method for a better resolution of the problem of estimating and predicting pollution, governed by Burgers' equations. The originality of the method consists in the introduction of an error function into the system's equations of state to model uncertainty in the model. The initial conditions and diffusion coefficients, present in the equations for pollution and concentration, and also those in the model error equations, are estimated by solving a data assimilation problem. The efficiency of the correction method is compared with that produced by the traditional method without introduction of an error function.Three test cases are presented in this study in order to compare the performances of the proposed methods. In the first two tests, the reference is the analytical solution and the last test is formulated as part of the “twin experiment”.The numerical results obtained confirm the important role of the model error equation for improving the prediction capability of the system, in terms of both accuracy and speed of convergence. 相似文献
35.
Isomers based on the bisindolylmaleimide architecture were reported in this Letter. Introducing hydroxyl to this architecture lead to quenching the fluorescence of bisindolylmaleimide. The fluorescence was recovered with its hydroxyl group esterified. Ester group can be easily transformed to hydroxyl group by hydrolysis reaction. Thus, a toggle-switchable fluorescence, ‘off-on’ cycle can be established on the basis of reversible esterification/hydrolysis reaction. 相似文献
36.
37.
Lyun-Su Kim Ki-dong Son Debasish Sarker Ji Hwan Jeong Sung Hong Lee 《Heat and Mass Transfer》2011,47(2):163-180
Small vapor compression refrigeration systems incorporate a non-adiabatic capillary tube called a capillary tube-suction line
heat exchanger (SLHX) in order to improve performance. The thermodynamic properties of the refrigerant in the capillary tube
and suction pipe are influenced by associated phenomena. This study compares various relevant models. Based on the comparison
recommended correlations were selected and the simulation results show that the friction factor model has the most dominant. 相似文献
38.
Recognizing and responding to students' thinking is essential in teaching mathematics, especially when students provide incorrect solutions. This study examined, through a teaching scenario task, elementary preservice teachers' interpretations of and responses to a student's work on a task involving reflective symmetry. Findings revealed that a majority of preservice teachers identified the student's errors from conceptual aspects of reflection rather than from procedural aspects. However, when they responded to the student's errors, preservice teachers tried to cope with them by invoking procedural knowledge. This study also revealed the three types of responses and two different forms of address by preservice teachers to student errors; these categories might provide insight into the difficulties arising in communication between students and teachers. 相似文献
39.
Catalytic one-pot synthesis of fenestrane derivatives from dienediynes was developed: fenestranes were synthesized in high yields by a dicobalt octacarbonyl-catalyzed tandem cycloaddition of dienediynes. 相似文献
40.
N-Phenyl alkyl amides were synthesized by the cobalt on charcoal-catalyzed one-pot reaction of alkene and aniline under carbon monoxide; this is the first heterogeneous catalytic formation of N-phenyl alkyl amides. 相似文献