全文获取类型
收费全文 | 230篇 |
免费 | 39篇 |
国内免费 | 17篇 |
专业分类
化学 | 18篇 |
力学 | 118篇 |
数学 | 17篇 |
物理学 | 133篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 7篇 |
2019年 | 3篇 |
2018年 | 6篇 |
2017年 | 6篇 |
2016年 | 4篇 |
2015年 | 5篇 |
2014年 | 7篇 |
2013年 | 17篇 |
2012年 | 13篇 |
2011年 | 22篇 |
2010年 | 23篇 |
2009年 | 15篇 |
2008年 | 12篇 |
2007年 | 21篇 |
2006年 | 19篇 |
2005年 | 13篇 |
2004年 | 14篇 |
2003年 | 11篇 |
2002年 | 10篇 |
2001年 | 7篇 |
2000年 | 9篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 5篇 |
1996年 | 7篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有286条查询结果,搜索用时 15 毫秒
101.
102.
103.
使用 ANSYS FLUENT 软件和 RNG k-ε 湍流模型分别研究了十字形、内十字形和花形结构的螺旋喷
嘴内部流动特性和耦合面换热特性。模拟结果研究表明,螺旋角 θ 越小喷嘴出口速度越高,喷出的水流更集中,
水流运动轨迹越清晰且规律越明显。同一工况下,θ=30°的花形喷嘴的换热效率和换热均匀性均优于其余两种喷嘴的值;耦合面努塞尔数 Nu 最大值会随着雷诺数 Re 不断增加而逐渐远离射流中心处(r/dj=0,dj 为喷嘴当量直径);
随着靶距 H 逐渐增大,Nu 逐渐减小,旋流效果逐渐减弱。当 H=2dj、4dj 时,Nu 最大值位于 r/dj=1 处;当 H=6dj 时,Nu 最大值位于射流中心处。 相似文献
104.
105.
A novel nonreflecting boundary condition, which converges to the specified time‐dependent boundary condition within any degree of accuracy, is introduced for the numerical simulation of hyperbolic systems and validated against the solution of two fundamental boundary value problems in fluids. First, transonic nozzle flow with backward acoustic disturbance is considered. Using high‐order aeroacoustic numerical schemes, the proposed nonreflecting boundary condition yields results that are in excellent agreement with those obtained using conventional nonreflecting boundary conditions based on the method of characteristics as well as with the results of the exact solution. The novel nonreflecting boundary condition, implemented into a semi‐analytical solution algorithm of unsteady bubbly cavitating nozzle flows, is also validated against results obtained using a Lagrangian finite volume scheme. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
106.
In this paper, the wave pattern characteristics of shock-induced two-phase nozzle flows with the quiescent or moving dusty
gas ahead of the incident-shock front has been investigated by using high-resolution numerical method. As compared with the
corresponding results in single-phase nozzle flows of the pure gas, obvious differences between these two kinds of flows can
be obtained.
Received 14 June 1996 / Accepted 19 October 1996 相似文献
107.
A study on heat transfer during thermoplastic composite tape lay-up process was done. To investigate the relation between major process variables, experiments as well as numerical simulations were performed. A small-scale tape lay-up system was built. A hot nitrogen torch was used to heat the prepreg tape. Right after the torch, a compaction roller was located to bond the prepreg plies. Temperatures inside the composite at four different locations through the thickness were measured, using thermocouples. Experiments were done for different process conditions. Numerical simulations also were performed, using the finite element code developed in this study. A numerical code was run for the same conditions as the experiment. Close agreement was observed between the numerical results and the experimental data. 相似文献
108.
R. K. Tyagi R. Rajesh Gaurav Singhal Mainuddin A. L. Dawar M. Endo 《Optics & Laser Technology》2003,35(5):395-399
Supersonic Chemical Oxy-iodine Laser has been developed using a Singlet Oxygen Generator (SOG) with a novel approach. Generated singlet oxygen is taken out of the SOG at an angle of 40° to avoid the problem of carry over of droplets, which is one of the major drawbacks of horizontal system. The system has been operated up to 22 mmol/s chlorine flow rates. Chlorine utilization and singlet oxygen observed have been more than 90% and 60%, respectively. The observed maximum output power was 350 W, thus yielding a chemical efficiency of 17.5%. 相似文献
109.
高能炸药(HE)柱壳沿轴向传播的稳定态爆轰,在置于炸药柱壳内部的泡沫塑料(工作流体)中产生很强的轴向击波,达到极高的压力和能量密度。适当设计,可使工作流体的流动接近一稳定态,与炸药爆轰以相同的相速度前进。击波阵面后的工作流体可用Nozzle流动方程很好地描述[1],Nozzle收缩段中的流动不受散开段流动的影响。利用这一性质,可以设计出达到极高压力和能量密度的超高速击波管,并且不受管壁物质强度的限制。数值模拟计算给出了上述稳定态物理图象,并显示出开始阶段轴向击波的形成过程及其后对稳定态的逼近,计算结果及物理图象与理论分析符合得很好。 相似文献
110.
Comparative Study of Flow Characteristics Inside Plasma Torch with Different Nozzle Configurations 总被引:1,自引:0,他引:1
X.?Q.?YuanEmail author H.?Li T.?Z.?Zhao F.?Wang W.?K.?Guo P.?Xu 《Plasma Chemistry and Plasma Processing》2004,24(4):585-601
A numerical analysis of the influence of different nozzle configurations on the plasma flow characteristics inside D.C plasma torches is presented to provide an advanced nozzle design basis for plasma spraying torches. The assumption of steady-state, axis-symmetric, local thermodynamic equilibrium, and optically thin plasma is adopted in a two-dimensional modeling of plasma flow inside the plasma torch. The PHOENICS software is used for solving the governing equations, i.e. the conservation equations of mass, momentum, and energy along with the equations describing the K-epsilon model of turbulence. The calculated arc voltages are consistent with the experimental results when arc current, gas inflow rate, and working gas are the same as the experimental parameters. Temperature, axial velocity contours inside plasma torches, profiles along the torch axis and profiles at the outlet section are presented to show the plasma flow characteristics. Comparisons are made among those torches. The results show that torches with different anode nozzle configurations produce different characteristics of plasma flows, which suggest some important ideas for the advanced nozzle design for plasma spraying. In order to validate the model and to show its level of predictivity, a comparison of the model with experimental results encountered in the literature is presented in the last part. 相似文献