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111.
This paper introduces a comparison of two of the methods which are most frequently used, at present, for the solution of an unsteady flow in the pipe system of internal combustion engines. These are (i) the method of characteristics and (ii) the two-step differential Lax-Wendroff method. In the case of homentropic flow a comparison is made between the lattice-point and mesh method of characteristics, and the two-step differential method is shown. In the case of non-homentropic flow the mesh method and two-step differential methods are also compared. The results show that for non-homentropic flow the two-step Lax-Wendroff method is faster and for engineering applications it is easier to implement on the computer. 相似文献
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<正>本期重点:1使用仿制图章工具2转换黑白影调和调整反差3调整画面影调与色彩4调整高光与增加细节5使用蒙版工具强化色彩和反差6调整构图与使用可选颜色7使用自由变换与调节曲线一张优秀的照片如何脱颖而出?是什么让它显得与众不同?如果你需要建议让自己的照片变得出色,我们的专家很乐意在此提供 相似文献
119.
Many common protective relays used in protection of power equipment are sensitive to phase sequence rotation of the utility supply. A method of analyzing the relay response to the respective phase rotation and other possible variables is described. It is demonstrated that phase rotation usually does not affect zero-sequence polarized relays. The technique is an exercise in voltage and current phasors, maximum torque lines of polarized relays, and the possible effect of system power factor. The following relays are discussed: directional power relay (IEEE Protective Device No.32) as used to protect prime movers on induction and synchronous generators from being motored by the generator due to loss of mechanical power; directional VAr relay (IEEE Protective Device No.55) as used to protect synchronous motors and synchronous generators from receiving VArs from the external power system due to loss of field excitation; directional current phase relay (IEEE Protective Device No.67) as used to detect reverse current flow into a power system from another source due to a system phase fault; and directional current ground relay (IEEE Protective Device No.67N) as used to detect reverse ground current flow into a power system from another source due to a system ground fault 相似文献
120.
Controlling Home and Office Appliances with Smart Phones 总被引:1,自引:0,他引:1
Most home and office appliances contain microprocessors. All these appliances have some user interface, but many users become frustrated with their appliances' difficult, complex functions. However, a new framework, the personal universal controller (PUC), lets users interact with appliances through a separate user interface device that they carry. Smart phones are good candidates for providing interfaces because they're common, their communication capabilities connect users to appliances, and they're already being used for a wide range of applications. The framework includes an abstract specification language for describing appliances, a two-way communication protocol, and automatic interface generation software that customizes user interfaces. This article overviews the PUC system and describes in detail the design and implementation of automatic interface generation for Microsoft's Smartphone platform. 相似文献