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排序方式: 共有331条查询结果,搜索用时 15 毫秒
31.
32.
Gaseous flow measurements in an internal combustion engine assembly using molecular tagging velocimetry 总被引:1,自引:0,他引:1
A molecular tagging velocimetry (MTV) system was applied for mapping in-cylinder flows in an internal combustion engine. The images were captured inside an optical engine assembly that reproduces operation of a 2.2 L four stroke gasoline engine. A recently developed algorithm to process MTV images is based on a fast-normalized spatial correlation approach implemented using MATLAB software. The code allows accurate detection of the MTV grid nodes displacements. It processes simultaneously velocity vector and circulation fields for individual cycles, and ensemble averages of those over a few hundred sequential cycles to obtain mean and standard deviation values. Then probability density functions are reconstructed to quantify cycle-to-cycle variability of the in-cylinder flow. 相似文献
33.
D. Vieru Corina Fetecau A. Sohail 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2011,9(3):161-172
The velocity field and the shear stresses corresponding to the motion of a second grade fluid between two side walls, induced
by an infinite plate that applies an accelerated shear stress to the fluid, are determined by means of the integral transforms.
The obtained solutions, presented under integral form in term of the solutions corresponding to the flow due to a constant
shear on the boundary, satisfy all imposed initial and boundary conditions. In the absence of the side walls, they reduce
to the similar solutions over an infinite plate. The Newtonian solutions are obtained as limiting cases of the general solutions.
The influence of the side walls on the fluid motion as well as a comparison between the two models is shown by graphical illustrations. 相似文献
34.
In the present investigation we have analyzed the boundary layer flow of a Jeffrey fluid over an exponentially stretching
surface. The effects of thermal radiation are carried out for two cases of heat transfer analysis known as (1) Prescribed
exponential order surface temperature (PEST) and (2) Prescribed exponential order heat flux (PEHF). The highly nonlinear coupled
partial differential equations of Jeffrey fluid flow along with the energy equation are simplified by using similarity transformation
techniques based on boundary layer assumptions. The reduced similarity equations are then solved analytically by the homotopy
analysis method (HAM). The convergence of the HAM series solution is obtained by plotting (h/2p)\hbar-curves for velocity and temperature. The effects of physical parameters on the velocity and temperature profiles are examined
by plotting graphs. 相似文献
35.
Iron oxides synthesized under acid conditions in a bioreactor using the bacteriumThiobacillus ferrooxidans or formed in nature under similar conditions resemble relatively “well”-crystallized ferrihydrites. Mössbauer spectra, however, show up significant differences between these and ferrihydrites, indicating sulfate to play a major role in determining the properties of the bacterial samples. 相似文献
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Soils developed from recent basalts of Marion Island in the Sub-Antarctic contain about 20% of a poorly crystalline iron oxide. The association of this phase with Al and Si appears to have a major influence on its Mössbauer spectra: whereas room-temperature spectra indicate a relatively regular structure, the magnetic hyperfine fields at 4.2K are lower than those of even the most poorly crystalline pure ferrihydrites. 相似文献
38.
Murad S. Taqqu 《Probability Theory and Related Fields》1975,31(4):287-302
39.
We construct extremal stochastic integrals
of a deterministic function with respect to a random Fréchet () sup-measure. The measure is sup-additive rather than additive and is defined over a general measure space , where is a deterministic control measure. The extremal integral is constructed in a way similar to the usual stable integral, but with the maxima replacing the operation of summation. It is well-defined for arbitrary , and the metric metrizes the convergence in probability of the resulting integrals.This approach complements the well-known de Haan's spectral representation of max-stable processes with Fréchet marginals. De Haan's representation can be viewed as the max-stable analog of the LePage series representation of stable processes, whereas the extremal integrals correspond to the usual stable stochastic integrals. We prove that essentially any strictly stable process belongs to the domain of max-stable attraction of an Fréchet, max-stable process. Moreover, we express the corresponding Fréchet processes in terms of extremal stochastic integrals, involving the kernel function of the stable process. The close correspondence between the max-stable and stable frameworks yields new examples of max-stable processes with non-trivial dependence structures.This research was partially supported by a fellowship of the Horace H. Rackham School of Graduate Studies at the University of Michigan and the NSF Grant DMS-0505747 at Boston University. 相似文献
40.