排序方式: 共有37条查询结果,搜索用时 15 毫秒
1.
2.
3.
MA Kang CHEN LinGen & SUN FengRui Postgraduate School Naval University of Engineering Wuhan China 《中国科学:化学》2010,(4)
An irreversible light-driven engine is described in this paper, in which the heat transfer between the working fluid and the environment obeys a linear phenomenological heat transfer law [ q ∝Δ(T -1)], with a working fluid composed of the bimolecular reacting system 2SO 3 F■S 2 O 6 F2. Piston trajectories maximizing work output and minimizing entropy generation are determined for such an engine with rate-dependent loss mechanisms of friction and heat leakage. The optimal control theory is applied to determi... 相似文献
4.
5.
Y.H. Hung Associate Professor S.W. Perng Graduate Student 《Experimental Thermal and Fluid Science》1988,1(4):305-313
A series of systematic experiments for measuring transient natural andforced convected heat fluxes in a one-sided heated vertical channel have beenconducted. The total heat input in transient natural and forced experiments iscomposed of four kinds modes: radiative heat loss, conductiveheat lossm, thermal capacity of the plate, and convective heat transfer in thetest channel. In the transient periods, the generalized correlations for estimatingtransient convective heat flux are proposed in natural and forced convectionexperiments. By using the proposed qc″ distributions, satisfactory agreementsare achieved between the transient Nux predictions and experimentaldata. 相似文献
6.
A. J. Al-Daini Research Student J. W. Railly Professor of Turbomachinery 《International Journal of Heat and Fluid Flow》1979,1(3):99-106
The representation of loss in a cascade by the appearance of blockage has been extended to deal with blade rows by the use of a source distribution to represent this blockage, and in the case of the actuator disc approximation, the presence of sources is confined to an axi-symmetric dìstribution over the actuator disc. It is found that if a typical dependence of loss (and consequently diffusion ratio) upon incidence for each section of an axial compressor rotor is represented in this manner, the influence of blockage on the axial velocity distribution may be found using the potential equation combined with the usual actuator disc approximation. Study of the behaviour of the controlling ordinary differential equation for the axial velocity ahead of the disc reveals that as the flow is reduced, the equation contains a singularity within the range of radius and a meaningful solution does not exist. This result is interpreted as the limit to continuous operation and reasonable agreement between this predicted limit and the appearance of abrupt stall (experimentally) is found. 相似文献
7.
Peng Cheng Ph.D. Michael A. Sutton Hubert W. Schreier Ph.D. Student Stephen R. McNeill 《Experimental Mechanics》2002,42(3):344-352
A full-field speckle pattern image correlation method is presented that will determine directly the complete, two-dimensional
deformation field during the image correlation process on digital images obtained using computer vision systems. In this work,
a B-Spline function is used to represent the object deformation field throughout the entire image area. This is an improvement
over subset-based image correlation methods by implicitly maintaining position and derivative continuity constraints among
subsets up to a specified order. The control point variables within the B-Spline deformation function are optimized iteratively
with the Levenberg-Marquardt method to achieve minimum disparity between the predicted and actual deformed images. Results
have shown that the proposed method is computationally efficient, accurate and robust. The general framework of this method
can be applied ton-dimensional image correlation systems that solve for multi-dimension vector fields. 相似文献
8.
F. Flores-Bazán C. Vera PhD Student 《Journal of Optimization Theory and Applications》2006,130(2):185-207
As a consequence of an abstract theorem proved elsewhere, a vector Weierstrass theorem for the existence of a weakly efficient solution without any convexity assumption is established. By using the notion (recently introduced in an earlier paper) of semistrict quasiconvexity for vector functions and assuming additional structure on the space, new existence results encompassing many results appearing in the literature are derived. Also, when the cone defining the preference relation satisfies some mild assumptions (but including the polyhedral and icecream cones), various characterizations for the nonemptiness and compactness of the weakly efficient solution set to convex vector optimization problems are given. Similar results for a class of nonconvex problems on the real line are established as well.Research supported in part by Conicyt-Chile through FONDECYT 104-0610 and FONDAP-Matemáticas Aplicadas II. 相似文献
9.
Chao-Kuang Chen ProfessorTzu-Li Tien Postgraduate Student 《Applied mathematics and computation》1996,80(2-3):225-244
Usually a linear differential equation is used to represent continuous dynamic systems, but a linear difference equation is used to represent discrete dynamic systems. AGO is one of the most important characteristics of grey theory, and its main purpose is to reduce the randomness of data. A linear differential equation, instead of a linear difference equation, is used to replace the grey differential equation to analyze discrete systems in this paper. Approximating a k-order derivative by operating after spline curve fitting of 1-AGO data, a model is directly established by means of the least square method. ARIMA models are used to analyze the leading indicator in advance, and the Fourier series with suitably chosen values of parameters is used in the fitting of leading indicator. This model is called the GDM(2, 2, 1) model. 相似文献
10.
Jan Mlynář Ph.D. Student 《Czechoslovak Journal of Physics》1995,45(10):799-816
In plasma physics there is a strong demand to reconstruct plasma cross-section from the projections measurements even though they were not complete. Therefore special methods of computer tomography (CT) are developed which include different physical assumptions. Within this report we present first results of a new pixels method CT code, which is suitable if the plasma cross-section is smooth in polar coordinates with a zero level near the origin. This is the case, e.g., in the study of neutral hydrogen transport into a tokamak plasma in the current plateau phase of the discharge. 相似文献