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141.
介绍了能够减轻乘坐高速列车时产生的耳朵不适感的风量控制式通风系统,该系统通过检测车内外的压力来控制进排气量,并且由模拟计算证实,该系统能够控制车内压力的波动,满足高速列车的舒适性需要。 相似文献
142.
Murat K. Aktas 《International Journal of Heat and Mass Transfer》2003,46(12):2253-2261
Effects of thermoacoustic wave motion on the developing natural convection process in a compressible gas-filled square enclosure were investigated numerically. In the cases considered, the left wall temperature is raised rapidly (impulsively or gradually) while the right wall is held at a specified temperature. The top and the bottom walls of the enclosure considered are thermally insulated. The numerical solutions of the full Navier-Stokes equations were obtained by employing a highly accurate flux-corrected transport algorithm for the convection terms and by a central differencing scheme for the viscous and diffusive terms. The strength of the pressure waves associated with the thermoacoustic effect and resulting flow patterns are found to be strongly correlated to the rapidity of the wall heating process. Fluid thermal diffusivity was found to affect the strength of the thermoacoustic waves and the resulting interaction with the buoyancy-induced flow. 相似文献
143.
In this paper, a new dynamic developable surface model is proposed. The proposed model represents developable surfaces using triangle meshes. A novel algorithm is proposed to introduce the Hamilton principle into these meshes such that the resulting developable model is dynamic, i.e., it can offer a time-dependent continuous path to deform the model. Applications with examples are presented; these show that the proposed technique can model buckled developable surfaces well, and can offer physically-realistic animations of deformed developable surfaces. 相似文献
144.
一种固定阈值的毫米波图像边缘检测方法 总被引:1,自引:0,他引:1
文章提出了一种固定阈值的毫米波图像边缘检测方法。根据图像的统计特征确定出像素的标准梯度强度,并采用单阈值对图像进行边缘粗定位,然后施行非最大抑制处理和滤波,得到最终检测结果。由于该算法对各幅毫米波图像设置相同的阈值,故能实现自动检测,同时还具有计算量小的特点。实验结果表明该方法进行毫米波图像边缘检测的有效性和可行性。 相似文献
145.
Chi-Chang Wang 《International Communications in Heat and Mass Transfer》2005,32(10):1337-1349
This research discusses the impacts of the surface area that the wavy surface gets more than the flat plate upon the aerosol particle deposition. Starting from the full Navier–Stokes equation, the mathematical analysis takes the thermophoretic motion formed by the temperature gradient and the fluid thermal expansion into consideration, and converts the governing equations into the boundary layer equation by the simple coordinate transformation and non-similarity method, and then works out these equations by the Spline Alternating-Direction Implicit method (SADI). The numerical value result reveals that the average deposition effect of the wavy plate is greater than the flat plate and that the increasing rate is nearly equal to the value obtained by dividing the surface area that the wavy plate gets more than the flat plate by 2.2. 相似文献
146.
Haruo Mimura Ryusei Sato Yu Sasaki Yuichi Furuyama Akira Taniike Kazutoshi Yoshida Akira Kitamura 《International journal of molecular sciences》2008,9(10):1989-2002
Tributyltin (TBT) released into seawater from ship hulls is a stable marine pollutant and obviously remains in marine environments. We isolated a TBT resistant marine Pseudoalteromonas sp. TBT1 from sediment of a ship’s ballast water. The isolate (109.3 ± 0.2 colony-forming units mL−1) adsorbed TBT in proportion to the concentrations of TBTCl externally added up to 3 mM, where the number of TBT adsorbed by a single cell was estimated to be 108.2. The value was reduced to about one-fifth when the lysozyme-treated cells were used. The surface of ethanol treated cells became rough, but the capacity of TBT adsorption was the same as that for native cells. These results indicate that the function of the cell surface, rather than that structure, plays an important role to the adsorption of TBT. The adsorption state of TBT seems to be multi-layer when the number of more than 106.8 TBT molecules is adsorbed by a single cell. 相似文献
147.
Camelia Betianu Florentina A Caliman Maria Gavrilescu Igor Cretescu Corneliu Cojocaru Ioannis Poulios 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2008,83(11):1454-1465
BACKGROUND: Heterogeneous photocatalysis is influenced by a number of parameters involving synergistic effects; hence, an experimental strategy design that considers interactions between the main variables is needed. The response surface methodology was applied for the investigation of photodegradation of 20 mg L?1 Orange II in aqueous solutions and for optimization of color removal efficiency. Preliminary studies were performed to identify the parameters to be selected for optimization. RESULTS: The input variables considered for experimental design were: solution initial pH, oxidizing agent (H2O2) initial concentration and UV‐A irradiation time. The multivariate experimental design allowed the development of a quadratic response surface model to be used for the prediction of color removal efficiency over the full range of the experimental region. Under the optimum conditions established in the region of experimentation (pH = 6.9, [H2O2]0 = 183 mg L?1 and t = 32 min), a 100% color removal efficiency was obtained in experiments. CONCLUSIONS: It was found that the variables considered have important effects on color removal efficiency. The results demonstrate that the use of experimental design strategy is indispensable for successful investigation and adequate modeling of the process because the interdependence of the reaction parameters cannot be neglected. Copyright © 2008 Society of Chemical Industry 相似文献
148.
G. N. Lilis A. Halder S. Telukunta S. Servetto 《International journal for numerical methods in engineering》2007,71(3):277-312
Many problems in geophysics, acoustics, elasticity theory, cancer treatment, food process control and electrodynamics involve study of wave field synthesis (WFS) in some form or another. In the present work, modelling of wave propagation phenomena is studied as a static problem, using finite element method and treating time as an additional spatial dimension. In particular, WFS problems are analysed using discrete methods. It is shown that a fully finite element-based scheme is very natural and effective method for the solution of such problems. Distributed WFS in the context of two-dimensional problems is outlined and incorporation of any geometric or material non-linearities is shown to be straightforward. This has significant implications for problems in geophysics or biological media, where material inhomogeneities are quite prevalent. Numerical results are presented for several problems referring to media with material inhomogeneities and predefined absorption profiles. The method can be extended to three-dimensional problems involving anisotropic media properties in a relatively straightforward manner. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
149.
利用Love波特性计算地基动力响应 总被引:5,自引:2,他引:3
本文利用Love波弥散特性在频域上对地基出平面振动及扭振问题进行了研究。在计算区域内结构将采用有限单元划分,而在边界上则根据Love 面波特性使用传递边界有限单元。本文同时讨论了不同模态波对结构动力响应的贡献。本文方法也适合于静力分析。 相似文献
150.
波浪力计算中的一个新边界元方法 总被引:8,自引:4,他引:4
滕斌 《水动力学研究与进展(A辑)》1994,(2):215-223
本文就波浪与结构物作用问题,提出了一个新的高阶边界元方法。较之Eatock Toylor和Chau的方法,本文在体内附助积分方程中应用了满足刚性水面条件和弱刚性底面条件的简单格林函数。计算速度相应地有所提高;漂浮结构的积分方程更为简洁;计算结果与Eatock Taylor和Chau的方法具有几乎相同的精度和收敛速度。 相似文献