The influence of low-frequency varying magnetic field on the pulsatile flow in a rigid round tube

ProjcctsupportedbytheNatiol1alNaturalScienceFoundatio11ofChinaThemagnatictherapy,asaneffccti\'emedicaltreatment,hasabroadapp1icatiQn.lnrecentyears,plentyofanimalandclinicalresearcheshavebeendoneandprovedthatmagneticfieldhassuchpositivecurativeefttctsasant…     

T-Y tube model of human ascending aortic input impedance

Arterialimpedancehasitsparticularsignificancebecauseitdescribesthephysicalandgeometricalcharactersofthewholearterialsystem.Moreover.itisagoodmeasureoftheleftventricleafterload.Numerousexperimentalandtheoreticalresearchesha\'ebeendoneinthisarea.Itisshownth…     

人体体循环输入阻抗的T-Y型管模型*

本文提出了模拟人体体循环输入阻抗的T－Y型管模型,它是O'Rourke[1]提出的,柳兆荣等[2]发展的非对称T型管模型的改进和推广.我们在非对称T型管基础上加添了代表人体两条腿的倒Y字型分叉管,从而形成了T－Y型模型,同时将模型中所有分支管都处理成具有纵向约束的粘弹性管,上肢终端小动脉床采用弹性腔模型,下肢终端小动脉床则采用传统的纯阻力形式.选取了适当参数值后,计算了正常生理情形下和高血压病理情形下的人体体循环的输入阻抗.结果显示理论模拟值和实测结果无论是生理情形或是病理情形都有良好的符合程度.T－Y型管模型比非对称T型管模型更接近人体体循环的生理结构.同时又比过份复杂的多重分叉管模型简单明了得多,因此在考察各种参数对升主动脉输入阴抗的影响.研究心室和血管的耦合机制中将是一个有实用价值的模型.     

时间空间均为二阶的新型NND差分格式

张涵信的研究表明,为了避免激波前后差分解的波动,在差分格式的改型方程中三阶导数的系数在激波上游必须是正的,而在激波下游则必须是负的.据此提出了一种新型的无波动、无自由参数耗散性的差分格式,它对时间和空间都是二阶的.证明了此格式是TVD的,而且是推广的二阶Годунов格式.在处理有激波的流场时,此格式是Lax-Wendroff格式的改进和推广.给出了若干算例,计算结果表明,此格式不仅无波动,而且具有形式紧凑、应用方便、分辨率高、稳定性准则中的Courant数较大的优点.     

恶性肿瘤的传质问题（Ⅱ）——药物传输部分

本文提出肿瘤中药物传输的三重介质模型·基于第（Ⅰ）部分流体动力学的计算结果，采用有限元方法，在不同初始和边界条件下求解了对流—扩散方程组·根据计算结果，详细分析了药物注射方式、分子量、淋巴、药物结合和坏死区等对抗体免疫球蛋白ＩｇＧ及其片断Ｆａｂ在肿瘤中浓度分布的影响·     

MASS TRANSPORT IN SOLID TUMORS (Ⅰ)──FLUID DYNAMICS

I.IntroductionCancerhasbeenthekillerinmanywesterncountriesonlysecondtothecardiovasculardiseaseformanyyears.Ditficultiesinearlydiagnosisisoneofthemajorobstaclesincancertreatment.However,recentlyitisreportedthatthetumorphysiologicalbarrier,whichpreventsdrugsfrompenetratingintothecoreoftumor,'mayconstituteanothermajorobstacleinkillingcancercallseffectivelyl'].Therefore,tostudythemasstransp.ortprocessintumorbecomesimportantinthatitmayprovidesomecriteriafordrugdesignanddrug-giningstrategies.Tradit…     

Flap side-edge noise mechanism and shape modification noise reduction design

Flap side-edge noise is a significant noise source for airplane at takeoff and landing stages. The generation mechanism of flap side-edge noise is analyzed by numerical simulation on unsteady flow field using Very Large Eddy Simulation(VLES). Two kinds of flap side-edge shape modifications are proposed, and their frequency spectrum and directivity of far-field noise are compared with the baseline configuration using permeable integral surface Ffowcs Williams and Hawkings(FW-H) acoustic analogy method to investigate their effects on noise reduction. Via the numerical simulation of flow field and acoustic field, it proves that the flap side-edge noise is broadband noise in nature. The different shapes of flap side-edge change the pattern of flow field, vortex structures and the development of vortex, thus having influences on noise source distributions and characteristics of far-field noise. The result shows that at the given 5° angle of attack, the proposed flap side-edge shape modifications can reduce the overall sound pressure level(OASPL) by 1 to 2 dB without decreasing the lift and drag aerodynamic performances.     

The oseen flow of finite clusters of spheres and the wake effect on the drag factor

In this paper, the wake effect on drag factor in the axisymmetric Oseen flow of the finite clusters of equally spaced spheres with same size is studied. Putting the Oseen lets on the centres of all the spheres, the series solution of the problem is obtained. By truncating the infinite series and applying the collocation method to solve a set of the linear algebraic equations, the approximate solution of the Oseen flow of finite clusters of spheres and the drag factor for each sphere are presented. The effect of the sphere number and spacing on the drag factor of each sphere under different Reynolds numbers are calculated and the wake effect as well as the shielding effect and the end effect are revealed. The influence of various parameters on the effects is considered and compared with the corresponding results of the Stokes flow. The convergence of the method is also studied numerically in this paper.     

Effect of the distributary of nasal meatuses on olfaction

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The dynamic coupling of left ventricle and systemic arteries

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