全文获取类型
收费全文 | 81篇 |
免费 | 6篇 |
国内免费 | 6篇 |
专业分类
化学 | 6篇 |
力学 | 30篇 |
数学 | 38篇 |
物理学 | 19篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 3篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 4篇 |
2013年 | 9篇 |
2012年 | 3篇 |
2011年 | 7篇 |
2010年 | 6篇 |
2009年 | 5篇 |
2008年 | 4篇 |
2007年 | 3篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2004年 | 3篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1984年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有93条查询结果,搜索用时 46 毫秒
81.
Turbulent flow around single concentric long capsule in a pipe 总被引:2,自引:0,他引:2
Mohamed F. Khalil Sadek Z. Kassab Ihab G. Adam Mohamed A. Samaha 《Applied Mathematical Modelling》2010
A numerical solution was developed for the equations governing the turbulent flow around single concentric long capsule in a pipe. First, a turbulence model was established for the concentric annulus between the capsule and the pipe to simulate the flow as axi-symmetric, two dimensional, steady flow without edge effect. Second, the same case was considered taking into account the edge effect. Finally, turbulence modelling was established to simulate the case as a three dimensional steady flow, with a view of investigating the validity of axi-symmetric flow assumption. Three different turbulence models were used: an algebraic model (Baldwin–Lomax model) and two types of two-equation models (k–ε and k–ω). Obtained results of pressure gradient along the capsule were compared with available experimental data to verify the used models. In addition, experimental data of the velocity profiles of other investigators were also used in this concern. The results predicted by the three different turbulence models were shown to agree well with the experimental data, though precision differed from one to another. 相似文献
82.
在全面调研了国内外关于两相在管道中的偏心圆柱塞状管流的研究文献之后,发现几乎都利用经验公式或近似估计式进行水力计算,这与石油工业中两相流的广泛应用极不相适应。根据流体力学中N-S方程对层流的描述,再结合经典的力学理论分析,对两相偏心圆柱塞状管流的相界面提出严密而科学的力学耦合条件,得到了完整描述偏心环状管流的适定的偏微分方程组,然后利用双极坐标变换化不规则的区域为规则的矩形域及计算机仿真技术,得到了两相流中偏心圆柱塞状管流的流动规律,对石油工业具有重要的工程应用价值。 相似文献
83.
84.
D. Mercuri G. Leone R. Barbucci R. Favaloro A. Facchini F. Signori S. Bronco F. Ciardelli 《Macromolecular Symposia》2008,266(1):74-80
Summary: Degeneration of intervertebral discs is the most common cause of back pain. The first phase of this degenerative process involves the nucleus pulposus. A rapid recovery of this structure can prevent further degradation of the annulus fibrosus. Guar Gum is an hydrophilic polysaccharide extracted from the seed endosperm of a plant. Through a cross-linking procedure a Guar hydrogel was synthesized. The Guar hydrogel could be injected by a syringe and it is a good candidate as a nucleus pulposus substitute. For the preparation of the artificial fibrosus annulus, commercially available polymer materials are tuned to achieve suitable mechanical properties. To achieve this peculiar behaviour, the main strategy investigated is the dispersion of hollow polymer micro spheres in a thermoplastic polymer matrix. Processing conditions and particle content are finely tuned to get the target mechanical behaviour. 相似文献
85.
Esad Tombarević & Igor Vu&scaron anović 《advances in applied mathematics and mechanics.》2011,3(3):354-369
Phase change in ice-water systems in the geometry of horizontal
cylindrical annulus with constant inner wall temperature and adiabatic
outer wall is modeled with an enthalpy-based mixture model. Solidification
and melting phenomena under different temperature conditions are
analyzed through a sequence of numerical calculations. In the case of freezing
of water, the importance of convection and conduction as well as the influence
of cold pipe temperature on time for the complete solidification is examined.
As for the case of melting of ice, the influence of the inner pipe wall
temperature on the shape of the ice-water interface, the flow and temperature
fields in the liquid, the heat transfer coefficients and the rate of melting
are analyzed. The results of numerical calculations point to good qualitative
agreement with the available experimental and other numerical results. 相似文献
86.
大间隙环流中偏心转子动特性系数的数值分析方法 总被引:4,自引:0,他引:4
基于作者用整体流动理论和Moody壁面摩擦系数方程建立的大间隙环流中转子动特性系数数值计算模型,应用摄动方法推导了大间隙环流流场非线性控制方程组的一阶摄动方程,提出了求解大间隙环流中偏心转子动力学特性系数的数值分析方法。用该方法得到的数值结果与已有的解析解和实验结果具有较好的一致性。 相似文献
87.
Antje Brucks 《Archive of Applied Mechanics (Ingenieur Archiv)》2008,78(1):33-47
Experimental results are presented on natural convection in a spherical shell of inner and outer radii r
1 = 14 mm and r
2 = 35 mm, with the inner sphere cooled and the outer sphere heated. The fluids filling the shell are two different silicon
oils having Prandtl numbers 39 and 233. Both spheres are fixed together and can be rotated. In the studied regime, both Coriolis
and centrifugal forces become significant. For sufficiently small Rayleigh numbers the resulting flow pattern is axisymmetric
and steady, consisting of a plume descending from the south pole of the inner sphere, and returning in the equatorial regions.
For greater Rayleigh numbers the flow becomes non-axisymmetric, with azimuthal modes m = 2 to 4 arising. We map out the critical Rayleigh number for the onset of these different modes, and consider how they vary
with increasingly rapid overall rotation. Detailed flow measurements are done by converting a standard 2D particle image velocimetry
system into a scanning quasi-3D PIV system. 相似文献
88.
《Comptes Rendus Mecanique》2017,345(1):11-20
The stability of the flow of a dielectric fluid confined in a cylindrical annulus submitted to a radial temperature gradient and a radial electric field is investigated theoretically and experimentally. The radial temperature gradient induces a vertical Archimedean buoyancy and a radial dielectrophoretic buoyancy. These two forces intervene simultaneously in the destabilization of the flow, leading to the occurrence of four types of modes depending on the relative intensity of these two buoyancies and on the fluid's properties: hydrodynamic and thermal modes that are axisymmetric and oscillatory, stationary columnar modes and electric modes which are stationary and non-axisymmetric modes. Experiments performed in a parabolic flight show the existence of non-axisymmetric modes that should be either columnar or helicoidal vortices. 相似文献
89.
电子直线加速器束流动力学的三维理论和计算 总被引:2,自引:0,他引:2
本文提出了电子直线加速器束流动力学计算的三维理论。将注入的脉冲束流划分为等电荷的环,追踪这些环在三维几何空间的运动,并在六维相空间内讨论束流的性能,给出束流在(r,p_r),(rθ,p_θ),(z,p_Z)三个相平面上的图象以及均方根发射度的数值。本文还介绍了应用三维理论的实例计算结果,并对影响径向发射度的因素作了讨论。 相似文献
90.
The experiments show that the travelling waves strongly vacillate with time due to the topographic forcing. Otherwise in the experiments with the same imposed external conditions but without topography, the baroclinic waves would travel regularly with almost no vacillation. It was found that a prominent feature in the flow with the topographic forcing is large-scale wave vacillation with a period of 127 annulus rotations, which is equivalent to approximately 26 days in the Earth's atmosphere. The experiments also show that the role of topography is to modulate the unstable baroclinic waves both in space and in time.In the second part of this paper, a series of comparative experiments is introduced to study the influences of heat sources and topography on the large-scale baroclinic background flows defined as the flow patterns determined by Ω, the angular velocity of the annulus rotation and △T, the radial temperature difference between the inner and outer walls of the annulus. The flow patterns depend 相似文献