全文获取类型
收费全文 | 533篇 |
免费 | 31篇 |
国内免费 | 5篇 |
专业分类
化学 | 262篇 |
晶体学 | 2篇 |
力学 | 56篇 |
数学 | 98篇 |
物理学 | 151篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 12篇 |
2021年 | 27篇 |
2020年 | 25篇 |
2019年 | 23篇 |
2018年 | 42篇 |
2017年 | 30篇 |
2016年 | 47篇 |
2015年 | 40篇 |
2014年 | 24篇 |
2013年 | 72篇 |
2012年 | 37篇 |
2011年 | 48篇 |
2010年 | 28篇 |
2009年 | 31篇 |
2008年 | 19篇 |
2007年 | 14篇 |
2006年 | 13篇 |
2005年 | 9篇 |
2004年 | 1篇 |
2003年 | 7篇 |
2002年 | 4篇 |
2001年 | 1篇 |
1999年 | 3篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1984年 | 2篇 |
排序方式: 共有569条查询结果,搜索用时 15 毫秒
121.
This paper presents an analytical solution of a thick walled cylinder com- posed of a functionally graded piezoelectric material (FGPM) and subjected to a uniform electric field and non-axisymmetric thermo-mechanical loads. All material properties, except Poisson's ratio that is assumed to be constant, obey the same power law. An exact solution for the resulting Navier equations is developed by the separation of variables and complex Fourier series. Stress and strain distributions and a displacement field through the cylinder are obtained by this technique. To examine the analytical approach, different examples are solved by this method, and the results are discussed. 相似文献
122.
A consistent flexibility matrix is presented for a large displacement equilibrium-based Timoshenko beam–column element. This development is an improvement and extension to Neuenhofer–Filippou [1] (1998. ASCE J. Struct. Eng. 124, 704–711) for geometrically nonlinear Euler–Bernoulli force-based beam element. In order to find weak form compatibility and strong form equilibrium equations of the beam, the Hellinger–Reissner potential is expressed. During the formulation process, an extended displacement interpolation technique named curvature/shearing based displacement interpolation (CSBDI) is proposed for the strain–displacement relationship. Finally, the extended CSBDI technique is validated for geometric nonlinear examples and accuracy of the method is investigated concluding improved convergence rates with respect to the general finite element formulation. Also it is seen that the use of force based formulation removes shear locking effects. The results demonstrate considerable accuracy even in presence of high axial loading in comparison with the displacement based approach. 相似文献
123.
Transport in Porous Media - Image-based simulations at pore scale provide direct insight into the impact of the microstructure on flow and transport processes in porous media. Diffusion is an... 相似文献
124.
Mahboubi Davoud Jafari Gavzan Iraj Saidi Mohammad Hassan Ahmadi Naghi 《Journal of Thermal Analysis and Calorimetry》2022,147(21):12253-12267
Journal of Thermal Analysis and Calorimetry - Lithium-ion batteries should continuously be operated at the optimum temperature range $$left( {15 sim 40 ,^circ C} right)$$ for the best... 相似文献
125.
Rajaei Amir Jafari Mohammad Ghani Kamal 《Journal of Thermal Analysis and Calorimetry》2020,142(3):1295-1302
Journal of Thermal Analysis and Calorimetry - The decomposition onset temperature, Tdecom, is an important parameter for investigating the thermal stability of chemicals. A novel method is... 相似文献
126.
Ebrahimi-Moghadam Amir Deymi-Dashtebayaz Mahdi Jafari Hosein Niazmand Amir 《Journal of Thermal Analysis and Calorimetry》2020,141(6):2573-2588
Journal of Thermal Analysis and Calorimetry - The energy consumption and greenhouse gases emissions in natural gas city gate stations are important issues in the natural gas industry. In order to... 相似文献
127.
Raziyeh Safa Ataallah Soltani Goharrizi Ebrahim Jahanshahi Javaran Saeed Jafari 《国际流体数值方法杂志》2020,92(1):55-78
A thermal-concentration smoothed profile-lattice Boltzmann method is proposed to study the effect of the concentration field on the dynamic behavior of nonisothermal cylindrical particles during the sedimentation process. The velocity, temperature, and concentration equations are solved using the lattice Boltzmann method. Moreover, the smoothed profile method is employed to enforce the nonslip boundary condition as well as constant temperature and constant concentration boundary conditions at the particles surfaces. Moreover, the Boussinesq approximation is used to couple the velocities, temperatures, and concentrations fields. The proposed combined method is validated by comparing the present numerical results with those found in the literature, showing good consistency. Then, the effect of the concentration buoyancy on the behavior of nonisothermal particles is discussed. In addition, the effect of Prandtl, Schmidt, and thermal Grashof numbers on the settling process is investigated. The results show that, by adding the effect of concentration, the maximum settling velocity of hot particles is reduced more relative to the cold ones; accordingly, the cold particles are settled faster than the hot ones. Finally, the sedimentation of two particles in a container at high thermal Grashof is investigated. It is shown that, at high thermal Grashof, there is an intense competition between the buoyancy force and gravity for the hot particles. The buoyancy flow generated leads to the reversal of the drafting-kissing-tumbling motion of the hot particles, making the particles move upward. 相似文献
128.
Foroutannia Ali Ghasemi Mahdieh Parastesh Fatemeh Jafari Sajad Perc Matjaž 《Nonlinear dynamics》2020,100(3):2699-2714
Nonlinear Dynamics - The brain is a complex system consisting of a large number of interacting neurons. Recently, a simple nonlinear biological model has been proposed for the up and down state... 相似文献
129.
130.
We obtain an upper bound for the independent domination number of a graph in terms of the domination number and maximum degree. 相似文献