全文获取类型
收费全文 | 492篇 |
免费 | 36篇 |
国内免费 | 27篇 |
专业分类
化学 | 57篇 |
晶体学 | 7篇 |
力学 | 112篇 |
综合类 | 5篇 |
数学 | 29篇 |
物理学 | 345篇 |
出版年
2024年 | 2篇 |
2023年 | 4篇 |
2022年 | 11篇 |
2021年 | 15篇 |
2020年 | 14篇 |
2019年 | 4篇 |
2018年 | 2篇 |
2017年 | 9篇 |
2016年 | 10篇 |
2015年 | 11篇 |
2014年 | 10篇 |
2013年 | 23篇 |
2012年 | 26篇 |
2011年 | 37篇 |
2010年 | 30篇 |
2009年 | 20篇 |
2008年 | 25篇 |
2007年 | 38篇 |
2006年 | 44篇 |
2005年 | 34篇 |
2004年 | 37篇 |
2003年 | 23篇 |
2002年 | 28篇 |
2001年 | 17篇 |
2000年 | 14篇 |
1999年 | 9篇 |
1998年 | 12篇 |
1997年 | 12篇 |
1996年 | 5篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1986年 | 1篇 |
排序方式: 共有555条查询结果,搜索用时 15 毫秒
101.
102.
Shielding effect and emission criterion of a screw dislocation near an interfacial blunt crack 下载免费PDF全文
Shielding effect and emission criterion of a screw dislocation near
an interfacial blunt crack are dealt with in this paper. Utilizing
the conformal mapping technique, the closed-form solutions are
derived for complex potentials and stress fields due to a screw
dislocation located near the interfacial blunt crack. The stress
intensity factor on the crack tips and the critical stress intensity
factor for dislocation emission are also calculated. The influence
of the orientation of the dislocation and the morphology of the
blunt crack as well as the material elastic dissimilarity on the
shielding effect and the emission criterion is discussed in detail.
The results show that positive screw dislocations can reduce the
stress intensity factor of the interfacial blunt crack tip
(shielding effect). The shielding effect increases with the increase
of the shear modulus of the lower half-plane, but it decreases with
the increase of the dislocation azimuth angle. The critical loads at
infinity for dislocation emission increases with the increase of
emission angle and curvature radius of blunt crack tip, and the most
probable angle for screw dislocation emission is zero. The present
solutions contain previous results as special cases. 相似文献
103.
104.
105.
使用叶片排间隙混合平面概念,完成离心压气机级多叶片排三元N-S方程计算。每个动静叶片排内的流动被认为是定常的且由相对独立的程序段进行运算。这样的串行程序很容易被改造为在并行系统上运行的SPMD并行程序。 相似文献
106.
P. Nageswara Rao 《Optics & Laser Technology》1989,21(4)
A laser pointer has been designed using a red diode laser (670 nm). The optics of the pointer consists of a four element collimating lens, two prism compressor and a two lens reversed Galilean afocal. The beam diameter of the laser pointer is 4.2 mm. 相似文献
107.
Used in chirped-pulse amplification system and based on multi-layer thin film stack, pulse compressor gratings (PCG) are etched by ion-beam and holographic techniques. Diffraction efficiency and laser-induced damage threshold rely on the structural parameters of gratings. On the other hand, they depend greatly on the design of multi-layer. A theoretic design is given for dielectric multi-layer, which is exposed at 413.1 nm and used at 1053 nm. The influences of coating design on optical characters are described in detail. The analysis shows that a coating stack of H3L (H2L)9H0.5L2.01H meets the specifications of PCG well. And there is good agreement of transmission between experimental and the theoretic design. 相似文献
108.
109.
Fukuji Inoko Tatsuya Okada Toshinori Muraga Yoko Nakano Takashi Yoshikawa 《Interface Science》1997,4(3-4):263-272
In bulk bicrystals strain induced grain boundary premelting (SIGBPM) occurs when heavy screw dislocation pileup can be held up to a certain high temperature, approximately 0.6T
M, where T
M is the melting point of bulk material in Kelvin. SIGBPM occurs at grain boundaries to which new twist component is added due to the rotation of both component crystals toward opposite direction about the axis perpendicular to the grain boundary plane. At the original grain boundary, grain boundary sliding takes place due to this relative rotation. In f.c.c. metals with relatively low stacking fault energies such as copper, nickel, brass(30Zn) and silver, dislocations dissociate into partials. Therefore high density tangled dislocations introduced during plastic deformation hardly loose. If these dislocations can be held to high temperatures, SIGBPM is promoted. Formation of static or dynamic recrystallized grains suppresses SIGBPM itself and the propagation of grain boundary cracks formed by SIGBPM. 相似文献
110.
利用位错光栅实现中空光束 总被引:2,自引:0,他引:2
讨论了螺旋波的特性,利用计算机模拟螺旋波与平面波干涉仪形成的光学位错图案制成光栅,利用不同阶次的位错光栅得到不同暗斑尺寸的中空光束。 相似文献