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11.
Ray P. S. Han Kai-Yuan Yeh Guoli Liu Diankui Liu 《International Journal of Engineering Science》1992,30(12):1773-1787
The scattering and diffraction of plane SH-waves, by an arbitrary-shaped cylindrical canyon in anisotropic media is formulated here. Analytical solutions are obtained via the complex function theory, using the orthogonal property of the Hermite functions to solve the resulting set of infinite algebraic equations. Expressions for scattered displacements and scattered stresses are given. Three cross-sectional profile types are used in the numerical simulation of the two-dimensional canyon topography: (a) a semi-circular profile, (b) a semi-elliptical profile and (c) a triangular profile. The results obtained in (a) and (b) are consistent with known solutions computed by Trifunac and his co-workers [1,3] using a different method. As the exact solution for (c) is not known to exist, the result given here is believed to be new and would therefore serve as a useful check for numerical analysts working in this area. 相似文献
12.
Indexed in current contents 相似文献
13.
The solubilities of ethyl palmitate, ethyl oleate, ethyl eicosapentaenoate (EPA) and ethyl docosahexaenoate (DHA) in supercritical
carbon dioxide were determined by a continuous flow method. The solubilities of fatty acid ethyl esters increased with pressure
and decreased as the temperature was increased. An empirical equation, similar to Chrastil's equation, was used to describe
the relationship between solute solubility and the density of carbon dioxide. The empirical equation was further used to qualitatively
estimate the separation efficiency of isolating EPA and DHA ethyl esters from fatty acid esters. The operating conditions
yielding high solubility gave fast extraction rate but resulted in low separation efficiency. Experiments were conducted to
separate ethyl EPA and ethyl DHA from a model mixture containing four fatty acid ethyl esters and from esterified squid visceral
oil. The experimental data compared closely with the calculated values. 相似文献
14.
Organic‐acid‐catalyzed sol–gel route for preparing poly(methyl methacrylate)–silica hybrid materials
Jui‐Ming Yeh Kuan‐Yeh Huang Chung‐Feng Dai B. G. Chand Chang‐Jian Weng 《应用聚合物科学杂志》2008,110(4):2108-2114
In this study, a series of organic–inorganic hybrid sol–gel materials consisting of a poly(methyl methacrylate) (PMMA) matrix and dispersed silica (SiO2) particles were successfully prepared through an organic‐acid‐catalyzed sol–gel route with N‐methyl‐2‐pyrrolidone as the mixing solvent. The as‐synthesized PMMA–SiO2 nanocomposites were subsequently characterized with Fourier transform infrared spectroscopy and transmission electron microscopy. The solid phase of organic camphor sulfonic acid was employed to catalyze the hydrolysis and condensation (i.e., sol–gel reactions) of tetraethyl orthosilicate in the PMMA matrix. The formation of the hybrid membranes was beneficial for the physical properties at low SiO2 loadings, especially for enhanced mechanical strength and gas barrier properties, in comparison with the neat PMMA. The effects of material composition on the thermal stability, thermal conductivity, mechanical strength, molecular permeability, optical clarity, and surface morphology of the as‐prepared hybrid PMMA–SiO2 nanocomposites in the form of membranes were investigated with thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, gas permeability analysis, ultraviolet–visible transmission spectroscopy, and atomic force microscopy, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
15.
16.
Wang Eric Ke Wang Fan Kumari Saru Yeh Jyh-Haw Chen Chien-Ming 《The Journal of supercomputing》2021,77(3):3024-3043
The Journal of Supercomputing - Accidents often occur in the earth—typhoons, floods, earthquakes, traffic accidents and so on. Whether these accidents can be timely and effectively responded... 相似文献
17.
The Toyota Production System (TPS) can result in huge benefits for companies and has been widely implemented around the world. Nevertheless, most adopters emphasize only the technical practices of the TPS, but neglect the critical role of human factors in the implementation of the TPS. Therefore, this study aims at developing an integrated TPS model that fully integrates the technical elements and human elements of the TPS with Total Quality Management (TQM) practices. An empirical study was conducted to confirm the causal relationships among these constructs. In the empirical study, questionnaires were mailed and e‐mailed to 620 companies that had implemented the TPS, and 151 of the completed questionnaires were valid. These 151 respondents were divided into eight categories. The results revealed that the implementation level of each construct was significantly different in each industry. The automobile and motorcycle industries have put a great deal of effort into the application of Humanity, Human Resource Management (HRM), and TQM practices and obtained good results. Other industries, however, ignored the implementation of HRM practices. The results also revealed that the early adopters enjoyed significant benefits from the implementation of the TPS, which led high‐tech companies to start adopting TPS practices and become lean enterprises. © 2011 Wiley Periodicals, Inc. 相似文献
18.
Samples with the same percentage crystallinity, supermolecular structure and lamellar thickness but different average molecular weight were prepared to distinguish the effect of tie chain density on fatigue crack propagation (FCP) behaviour. This alteration in molecular weight was accomplished by controlled chain degradation during thermal annealing. A significant decrease in FCP resistance was observed when samples were annealed at different temperatures for various amounts of time. In addition, an examination of the fracture surfaces of these specimens indicates a transition to a more brittle-type behaviour when annealed for longer periods of time at any specific annealing temperature. The decrease in FCP resistance is attributed to a decrease in the tie chain density. 相似文献
19.
Estimating discharge in gravel‐bed river using non‐contact ground‐penetrating and surface‐velocity radars 下载免费PDF全文
Discharge measurement is a critical task for gravel‐bed channels. Under high‐flow conditions, the elevation of the riverbed changes significantly by intensive torrential flow. The stage–discharge relations commonly used for stream discharge estimation may no longer be adequate. The contact‐type velocity measuring is also subject to measurement errors and/or instrument failures by the high‐flow velocities, driftwood, stumps, and debris. This study developed a new real‐time method to estimate river discharge in gravel‐bed channels. A systematic measuring technology combining ground‐penetrating radar and surface‐velocity radar was employed. The rating curves representing the relations of water surface velocity to the channel cross‐sectional mean velocity and flow area were established. Stream discharge was then deduced from the resulting mean velocity and flow area. The proposed method was examined in a steep gravel‐bed reach of the Cho‐Shui River in central Taiwan. The estimated stream discharge during three flood events were compared to the prediction by using the stage–discharge relation and the index‐velocity method. The proposed method of this study is capable of computing reasonable values of discharge for an entire flood hydrograph, whereas the other two methods tend to produce large extrapolation errors. Moreover, when the computed discharge is used in 2D flood flow simulation, the proposed method demonstrates better performance than the commonly used stage–discharge and index‐velocity methods. 相似文献
20.
Te-Yung Fang Pa-Chun Wang Chih-Hsien Liu Mu-Chun Su Shih-Ching Yeh 《Computer methods and programs in biomedicine》2014