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941.
本文研究了具有低阶项的散度型椭圆方程-(a_(ij)u_(x_i))_(x_j)+b_iu_(x_i)-(d_ju)_(x_j)+cu= (f_j)_(x_j),a.e.x∈Ω的解在Morrey空间上的局部正则性,其中a_(ij)∈VMO∩L~∞(Ω),低阶项系数属于适当的Morrey空间. 相似文献
942.
943.
In this paper, we give precise formulas for the general two-dimensional recursion sequences by generating function method, and make use of the multivariate generating functions asymptotic estimation technique to compute their asymptotic values. 相似文献
944.
The flow structures were investigated around micro bubbles on extremely thin wires during subcooled nucleate boiling.Jet flows emanating from the bubbles were observed visually with the fluid field measurement using high-speed photography and a PIV system.The jet flows induced a strong pumping effect around a bubble.The multi-jet structure was further observed experimentally, indicating the evolution of flow structure around micro bubbles.Numerical simulations explore that the jet flows were induced by a strong Marangoni effect due to high temperature gradients near the wire.The bubble interface with multi-jet structure has abnormal temperature distribution such that the coolest parts were observed at two sides of a bubble extending into the subcooled bulk liquid rather than at the top.Evaporation and condensation on the bubble interface play important roles not only in controlling the intensity of the jet flow,but also in bringing out the multi-jet structure. 相似文献
945.
Multi-Phase Flow and Heat Transfer of a Micro-Pump Thermally Driven by a Multi-Output Pulse Laser
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We present an experimental study of multi-phase flow and heat transfer in a micro-tube induced by a multi-output pulse laser. Extensive flow and heat transfer measurements and visualization experiments have been carried out to characterize the micro-pump behaviour under various conditions. The experiments reveal extremely unsteady and complex flow patterns in the micro tube with the flow closely related with generation and collapse of bubbles.It is found that the flow rates are controlled by the heating and condensation conditions within the tube. The laser pulse duration, pulse interval and output-power as well as the tube diameter all show a strong influence on the flow rate of the micro-pump. This study provides a basis for the design of thermally-driven micro-pump induced by a pulsed laser beam. 相似文献
946.
947.
948.
This paper is concerned with the distributional properties of a median unbiased estimator of ARCH(0,1)coefficient.The exact distribution of the estimator can be easily derived,however its practical calculations are too heavy to implement, even though the middle range of sample sizes.Since the estimator is shown to have asymptotic normality,asymptotic expansions for the distribution and the percentiles of the estimator are derived as the refinements.Accuracies of expansion formulas are evaluated numerically,and the results of which show that we can effectively use the expansion as a fine approximation of the distribution with rapid calculations.Derived expansion are applied to testing hypothesis of stationarity,and an implementation for a real data set is illustrated. 相似文献
949.
Compensating large PMD by a fiber grating 总被引:1,自引:0,他引:1
In this paper, the first- and second-order polarization mode dispersion (PMD) with the amount of 132.994-ps differential group-delay (DGD) and maximum 476.129-ps/nm second-order PMD can be compensated by a two-stages PMD compensator at a 40-Gb/s optical fiber communication system. The first stage has one free degree that is used for first order and high orders PMD compensations by rotating the state of 相似文献
950.