Navier－Stokes方程组的一个一致有效渐近解

本文利用多重尺度法[1,2]研究了大雷诺数情况下的平板绕流问题,得到了Navier-Stokes方程的一个一致有效渐近解。     

ON THE MIXED PROBLEMS IN AN EIASTIC PIANE WITH PERIODIC CRACKS

ＯＮＴＨＥＭＩＸＥＤＰＲＯＢＬＥＭＳＩＮＡＮＥＩＡＳＴＩＣＰＩＡＮＥＷＩＴＨＰＥＲ１ＯＤＩＣＣＲＡＣＫＳＺｈｅｎｇＫｅ（郑可）（ＷｕｈａｎＵｎｉｖｅｒｓｉｔｙ）ＯＮＴＨＥＭＩＸＥＤＰＲＯＢＬＥＭＳＩＮＡＮＥＩＡＳＴＩＣＰＩＡＮＥＷＩＴＨＰＥＲ１ＯＤＩ...     

Excellent扩张和弱维数

在这篇文章里，我们证明了，当环Ｓ是Ｒ的ｅｘｃｅｌｌｅｎｔ扩张，Ｍ是Ｓ－模时，Ｍ做为Ｓ－模的弱维数与Ｍ做为Ｒ－模的弱维数相等。     

On the Average of Exponents

ＯｎｔｈｅＡｖｅｒａｇｅｏｆＥｘｐｏｎｅｎｔｓＣａｏＨｕｉｚｈｏｎｇ（曹惠中）（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，ＳｈａｎｄｏｎｇＵｎｉｖｅｒｓｉｔｙ，Ｊｉｎａｎ２５０１００）Ａｂｓｔｒａｃｔ：Ｌｅｔｎ＞１ａｎｄｂｅｔｈｅｐｒｉｍｅｆａ...     

完全可压缩渗流驱动问题的特征线有限元方法及其误差分析

多孔介质中渗流驱动问题数值方法的研究，对合理经济地开发油田，了解地下油水运动规律有一定意义。特征线法结合差分或有限元法解渗流问题，在理论和应用上获得了成功３－５，但还有很多问题需进一步研究２．前人研究多是假定流体不可压或微可压，本文研究一类完全可压缩两相驱动问题。采用特征线法与有限元法相结合，构造并分析了全离散数值格式，基于周期性假设，证明了最优Ｌ２模误差估计。     

关于αn~k模1的分布

讨论了αｎ￣ｋ模１的分布，证明了对于有无穷多个自然数ｎ满足     

Physical and radiobiological parameters of proton beams up to 31 MeV

Summary Frequency distributions of energy deposition in microscopic tissue volumes determined by means of a ?Rossi type? proportional counter for 31, 12 and 8 MeV proton beams and, dose response curves for mortality and chromosome aberrations in cultured human cells exposed to the same beams are analysed with a view to determining suitable parameters to specify radiation quality. The behaviour of quantities LET,Z ^*2/β² and the microdosimetric parameter as a function of energy are compared with the corresponding behaviour of the most significant radiobiological parameters as mean lethal dose per targetD ₀, mean inactivation dose , intensity of chromosome aberrations, and dicentrics. It is shown that is the most suitable physical parameter to characterize the relative effectiveness of protons in the (8÷31) MeV range. Work partially supported by grant No. 8000165896 for the Finalized Project ?Tumor Growth Control?.     

Temperature dependence of the linewidth of the first-order Raman spectra for MnF2 crystal

The first-order Raman spectra ofE _gandA _1g modes in MnF₂ crystal were measured at temperatures from 4.2 to 563 K, and the values of the linewidths obtained. The temperature dependence of the linewidths was analyzed by the phonon dispersion curves based on the rigid ion model, and the result showed that it was caused approximately by the cubic anharmonic term in crystal potential energy.     

Equilibrium theory for the hard-core systems

It is found that the density expansion in the argument of the exponential function gives a fine convergence on the equation of state of the hard-sphere system. The pair distribution function and the equation of state is constructed by an intuitive kinetic theoretical method. The equation of state of the hard-core system with attractive potential is constructed semiempirically with the aid of this simple analytical result, and Kamerling-Onnes' constant of the critical point is obtained analytically.     

Near-i.r. Absorption of H2O and D2O in the liquid and supercooled range

Summary Results are reported on near-i.r. absorption spectra of H₂O and D₂O down to the temperature region of supercooled liquid. No anomalous behaviour is observed when the absorbance at any given frequency is studied as a function of temperature. A critical-exponent behaviour strikingly correlating with that exhibited by transport properties is instead observed when spectral deconvolution methods are used. Results are discussed in relation with current views on water structure, based on molecular-dynamics simulation results and connectivity calculations.

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Riassunto Si riportano risultati sugli spettri di assorbimento i.r. di H₂O e D₂O fino alla regione di temperature del liquido sopraraffreddato. L'andamento dell'assorbanza a frequenza costante in funzione della temperatura non mostra alcuna indicazione di comportamento anomalo. Al contrario, quando gli spettri sono analizzati con metodo di deconvoluzione, si osserva un comportamento di tipo esponente critico, che correla straordinariamente bene con quello mostrato dalle proprietà di trasporto. I risultati sono discussi anche in relazione ai piú recenti modelli di struttura dell'acqua, derivanti dai risultati di simulazione e dai calcoli di connettività.

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Резюме Приводятся результаты для спектров инфракрасного поглощения H₂O и D₂O для температур переохлажденной жидкости. Не обнаружено аномального поведения, когда поглощательная способность при заданной частоте изучается как функция темпетатуры. Напротив, при анализе спектров с помощью спектральных методов конволюции наблюдается поведение типа критической экспоненты, которое коррелирует с поведением, определяемым транспортыми свойствами. Полученные результаты обсуждаются в связи с недавними моделями структуры воды, полученными на основе моделирования молекулярной динамики и нычислений связности.