全文获取类型
收费全文 | 116篇 |
免费 | 15篇 |
国内免费 | 11篇 |
专业分类
化学 | 38篇 |
晶体学 | 2篇 |
力学 | 13篇 |
数学 | 2篇 |
物理学 | 35篇 |
综合类 | 52篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 1篇 |
2014年 | 7篇 |
2013年 | 10篇 |
2012年 | 10篇 |
2011年 | 11篇 |
2010年 | 7篇 |
2009年 | 13篇 |
2008年 | 8篇 |
2007年 | 8篇 |
2006年 | 3篇 |
2005年 | 9篇 |
2004年 | 4篇 |
2003年 | 7篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 5篇 |
1991年 | 1篇 |
1987年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有142条查询结果,搜索用时 15 毫秒
21.
22.
以汽车机械式自动变速系统(AMT)的离合器结合过程为研究对象,建立起以输入非线性动力传动系统数学模型。进一步主基于微分几何的反馈线性化方法,将原非线性系统等价为完全可控型线性模型。对该系统实施PID控制,跟踪理想整车加速度,并作了计算机仿真,仿真及分析结果表明,系统稳定、跟踪性态良好。 相似文献
23.
A. V. Proskurin A. M. Sagalakov 《Journal of Applied Mechanics and Technical Physics》2008,49(3):383-390
The stability of the plane flow of an electrically conducting fluid with respect to small perturbations was studied at large
Reynolds numbers in the presence of a longitudinal magnetic field. The dependence of the critical Reynolds number on the electrical
conductivity is investigated. At large Reynolds numbers, a new branch of instability and a sudden change in the critical Reynolds
numbers is found.
__________
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 3, pp. 45–53, May–June, 2008. 相似文献
24.
建立具有简化转向阻力矩模型的电动助力转向系统模型,提出基于横向动力学反馈控制的电动助力转向控制策略,运用Matlab/Simulink工具进行模型的时域仿真,通过实车试验验证所提出的控制策略.研究结果表明,基于横向动力学反馈控制的电动助力转向控制策略改善了车辆的动态性能,提高了车辆的稳定性,横摆角速度和侧向加速度反馈控制效果比单独横摆角速度反馈控制效果更好. 相似文献
25.
为标定小型实心转子静电陀螺仪用自准直式光电传感器的性能,设计了一个专用的性能测试系统。传感器性能测试表明,被测小型自准直式光电传感器的分辨率优于1^#,传感器性能测试系统满足使用要求。 相似文献
26.
Novel π-conjugated donor compounds based on the strong electron-donating ferrocene moiety and dithiafulvalene donors exhibited increased electron donor ability. The ferrocenylketones 4a,b, 5, 8 and 9 were synthesized via described methods, and allowed to react with 2-dimethoxyphosphinyl-1,3-benzodithiole (13) in the presence of n-BuLi at −78°C in dry THF to afford the corresponding ferrocene-dithiafulvalenes 14a,b, 18, 19 and 1,1′-bis(benzo-1,3-dithiol-2-ylidene)ethyl]ferrocene (15). Electrochemical properties of these new donor compounds were studied using cyclic voltammetry (CV) and UV-Vis spectra. CV and absorption spectra of the new compounds were studied in comparison with ferrocene (6) and dibenzo-tetrathiafulvalene DB-TTF 3. Two-electron and three-electron redox behaviors were observed as two waves. The absorption spectra showed a red-shift with a slight increase in the absorption intensities. 相似文献
27.
Self-consistent electrostatic intersite potentials and atomic charges have been calculated. Lattice cohesion energy for NaTCNQ has been reproduced when polarization of TCNQ- anion in the lattice was taken into account. 相似文献
28.
张若京 《应用数学和力学(英文版)》2011,32(12):1515-1524
A one-dimensional momentum conservation equation for a straight jet driven by an electrical field is developed. It is presented
in terms of a stress component, which can be applied to any constitutive relation of fluids. The only assumption is that the
fluid is incompressible. The results indicate that both the axial and radial constitutive relations are required to close
the governing equations of the straight charged jet. However, when the trace of the extra stress tensor is zero, only the
axial constitutive relation is required. It is also found that the second normal stress difference for the charged jet is
always zero. The comparison with other developed momentum equations is made. 相似文献
29.
B. D. Drobenko 《Journal of Applied Mechanics and Technical Physics》2005,46(5):624-634
This paper describes a procedure for the mathematical and numerical modeling of the thermomechanical behavior of electrically conducting solid bodies exposed to an external electromagnetic field. The constitutive equations for the electromagnetic field are the Maxwell equations written for the region of the solid body and the ambient medium. The stress-strain state of the solid is described using the relations for nonisothermal elastoplastic flow. The effects of the electromagnetic field on the heat-transfer and deformation processes are taken into account via heat release and ponderomotive forces, respectively. The relations between the electric and magnetic inductions and the corresponding field strengths are considered nonlinear. All physicomechanical parameters of the body material are temperature dependent.__________Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 46, No. 5, pp. 14–26, September–October, 2005. 相似文献
30.
外电场对荷电颗粒静电凝聚的影响 总被引:6,自引:1,他引:6
为了定量地分析外电场对荷电颗粒静电凝聚的影响,在理论分析和数值模拟的基础上,求解荷电颗粒凝聚的数量平衡方程,分析比较外电场存在与否时,颗粒数量浓度的变化关系。结果表明:外电场促进荷电颗粒间的凝聚;对于初始对称双极荷电颗粒,外电场不改变颗粒初始电荷分布的对称性,并且带任意电荷量的颗粒的数量浓度随凝聚时间单调减少;对于初始非对称双极荷电以及单极荷电颗粒,其数量浓度并非都随凝聚时间单调减少。 相似文献