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排序方式: 共有328条查询结果,搜索用时 31 毫秒
1.
This work is devoted to the numerical solution of the Navier–Stokes equations for compressible viscous fluids. Finite element approximations and stabilization techniques are addressed. We present methods to implement discontinuous approximations for the pressure and the density. An upwinding methodology is being investigated which combines the ideas behind the stream line Petrov–Galerkin method and the flux limiter methods aiming to introduce numerical diffusion only where it is necessary. 相似文献
2.
Mixed and hybrid finite element methods for the resolution of a wide range of linear and nonlinear boundary value problems (linear elasticity, Stokes problem, Navier–Stokes equations, Boussinesq equations, etc.) have known a great development in the last few years. These methods allow simultaneous computation of the original variable and its gradient, both of them being equally accurate. Moreover, they have local conservation properties (conservation of the mass and the momentum) as in the finite volume methods.The purpose of this paper is to give a review on some mixed finite elements developed recently for the resolution of Stokes and Navier–Stokes equations, and the linear elasticity problem. Further developments for a quasi-Newtonian flow obeying the power law are presented. 相似文献
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A prenyloxycoumarin from Psiadia dentata 总被引:2,自引:0,他引:2
Fortin H Tomasi S Jaccard P Robin V Boustie J 《Chemical & pharmaceutical bulletin》2001,49(5):619-621
A new coumarin identified as 5-hydroxy-6-methoxy-7-(3-methyl-but-2-enyloxy)-2H-1-benzopyran-2-one (isoobtusitin) was isolated from Psiadia dentata. This compound showed, in vitro, a moderate inhibitory activity against poliovirus and a very weak activity against (HIV), whereas it was inactive against (HSV1), (VSV), and murine tumoral cell lines (3LL, L1210). 相似文献
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M. Fortin 《Numerische Mathematik》1985,46(2):269-279
Summary We define a second-degree nonconforming element on tetrahedra. We build a basis for the opproximation space derived from this element. We prove a discrete regularity property similar to the one that holds for the corresponding two-dimensional element.This work was partly supported by NSERC and by the Ministère de l'Education du Québec 相似文献
8.
The use of recombinant baculoviruses as high level expression systems is becoming more and more popular. This review aims to provide a summary of the impact of this expression system in biochemistry and biotechnology, highlighting important advances that have been made utilizing the system. The potential of newly developed multiple baculovirus expression systems to enable the reconstruction of complex biological molecules and processes is also reviewed. 相似文献
9.
Eleven human hair samples were taken from the Chinese residents of Hong Kong for the study of hair trace elemental level and
environmental exposures. Absolute neutron activation analysis and Ge(Li) gamma-ray spectrometry were applied in the determination
of the trace elemental level. All results are reported in parts per million except for sulfur and oxygen which are reported
in percent. The trace element content of hair from a drug addict was found to be considerably different from other sampled
people. Comparison of the normal concentrations of the trace elements of the Chinese residents of Hong Kong was made with
those from people of various other national, socio-cultural and environmental backgrounds. It was found that together with
a few other trace elements, Ni, Sr, Zr and Hg content of the Chinese Residents of Hong Kong show a higher level than those
of the other sampled people. 相似文献
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F. F. Dyer J. F. Emery L. C. Bate 《Journal of Radioanalytical and Nuclear Chemistry》1987,110(1):221-226
A method was developed to determine thorium and uranium in semiconductor potting plastics. The method is based on neutron activation and subsequent radiochemical separation to isolate and permit measurement of the daughter products233Pa and239Np of the induced233Th and239U. These plastics typically contain macro amounts of silicon, bromine and antimony and nanogram per gram amounts of thorium and uranium. The radiochemical method provides the necessary sensitivity and makes it possible to easily attain adequate decontamination of the tiny amounts of233Pa and239Np from the high levels of radioactive bromine and antimony.Deceased 相似文献