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Working range optimization for turbine and compressor blading 总被引:1,自引:0,他引:1
A partially reduced SQP algorithm for a multiple setpoint industrial design optimization problem is presented. It is highlighted that the modularity of this concept has made it possible to apply it to problems as complex as working range optimization in high-temperature gas turbine and compressor blade design. Further emphasis is drawn on parallelization aspects and practical experiences in engineering practice. 相似文献
514.
轴流压气机转子尖区三维紊流特性 总被引:8,自引:3,他引:5
用三维激光多普勒测速系统测量研究了低速大尺寸单级压气机设计状态转子内尖区三维紊流流场.结果表明,设计状态下叶尖泄漏涡是造成压气机转子尖部素流脉动的主要因素,其造成的高素流区沿流向逐渐扩大,并缓慢向通道中部和低叶高方向移动,紊流强度值随旋涡的增强而增大.在泄漏涡影响区域中,径向脉动水平最高,轴向和切向脉动水平相近,三个剪切应力中,轴向一径向最大,切向一径向次之,轴向一切向最小.在叶片通道后段,泄漏涡发生破裂,导致更强、更大范围的紊流脉动,剪切应力中切向-径向应力较高.在叶尖吸力面角区后半部的角涡,紊流强度大,剪切应力也大,尤其是切向-径向剪切应力. 相似文献
515.
发展了立方准晶的位错弹性理论.通过引入位移势函数,使得立方准晶的反平面弹性动力学问题归结为求解两个波动方程,得到了运动螺型位错的位移场、应力场与能量的解析表达式及运动位错的速度极限.这些为研究此固体材料的塑性变形的物理机理提供了重要的信息. 相似文献
516.
附面层吸除对压气机叶栅稠度特性影响 总被引:14,自引:3,他引:14
数值模拟了不同稠度下吸气量及位置对某大转角吸气式压气机叶栅气动性能影响。结果表明,附面层吸除(BLS)使得吸力面角区低能流体积聚减弱,气流折转能力加强;随稠度增加,叶栅总压损失最高降低分别为32.9%、27.7%和25.1%,出口气流角最大增加值为5.0°、4.2°和3.1°,即小稠度叶栅具有较佳气动性能;BLS导致的栅内扩压能力恢复和通道涡三维分离效应的改善应是确定最佳设计参数的判定原则。吸气式叶栅附面层承受逆压梯度能力强的特点为高负荷、小稠度压气机设计提供了极具潜力的技术途径。 相似文献
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518.
B. Sreenivasa Reddy M. Sreenath Reddy Ch. Gopal Reddy P. Yadagiri Reddy K. Rama Reddy 《Radiation measurements》2003,36(1-6):503-506
Radon/thoron levels are estimated in Khammam district as a part of “Radon/thoron mapping” program in Andhra Pradesh, India. About 100 dwellings were chosen at random covering most parts of Khammam district. Twin chamber cup dosimeters consisting of solid-state nuclear track detectors (SSNTDs, LR-115, Type-II) were used to evaluate the radiation levels at quarterly intervals for a period of one calendar year. The average radon and thoron concentrations were found to be 39.1±13.3 and 19.4±14.9 Bq/m3, respectively. Seasonal variations of radon/thoron levels were also studied. Variations of radon/thoron concentration levels with different types of dwellings have been studied. In the bare flooring dwellings thoron levels were found to be highest in comparison to concrete, limestone and marble floorings. 相似文献
519.
The residual stresses induced by using self-drilling screws on polycarbonate plates were investigated by the hybrid method which incorporates the digital photoelastic method and finite element method (FEM). Different types of screws lead to different photoelastic fringe patterns, which provide the boundary conditions needed in the numerical simulation. By changing the two main parameters (pressure and temperature), the FEM results can be matched well with the experimental results for drilling at 0° tilt angle. For drilling at other tilt angles, the photoelastic fringe patterns provide useful information for failure analysis. 相似文献
520.
A. Sarhangi Fard M. A. Hulsen H. E. H. Meijer N. M. H. Famili P. D. Anderson 《国际流体数值方法杂志》2012,68(8):1031-1052
Two different techniques to analyze non‐Newtonian viscous flow in complex geometries with internal moving parts and narrow gaps are compared. The first technique is a non‐conforming mesh refinement approach based on the fictitious domain method (FDM), and the second one is the extended finite element method (XFEM). The refinement technique uses one fixed reference mesh, and to impose continuity across non‐conforming regions, constraints using Lagrangian multipliers are used. The size of elements locally in the high shear rate regions is reduced to increase accuracy. FDM is shown to have limitations; therefore, XFEM is applied to decouple the fluid from the internal moving rigid bodies. In XFEM, the discontinuous field variables are captured by using virtual degrees of freedom that serve as enrichment and by applying special integration over the intersected elements. The accuracy of the two methods is demonstrated by direct comparison with results of a boundary‐fitted mesh applied to a two‐dimensional cross section of a twin‐screw extruder. Compared with non‐conforming FDM, XFEM shows a considerable improvement in accuracy around the rigid body, especially in the narrow gap regions. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献