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291.
Phase transition phenomenon of the 1-dodecanol monolayer at the air/water interface was studied by the dynamic γ(t) curves and the adsorption isotherm obtained by ellipsometry at 20 °C. The surface-concentration adsorption isotherm clearly showed three abrupt increases at bulk concentration C of 1.3 × 10−9, 2 × 10−9 and 3.7 × 10−9 mol/mL, respectively. The 1st and the 3rd transitions observed herein, that were typical 2D first-order transitions, were consistent with the gas to liquid expanded (G–LE) and the liquid expanded to liquid condensed (LE–LC) phase transitions observed in a previous tensiometry study. The 2nd transition that occurred at C = 2 × 10−9 mol/mL was not identified from any previous dynamic surface-tension profiles. Judging from the substantial increase in the film thickness of the transition, it was believed that the orientation change of the adsorbed molecule was involved in the LE phase. A LEh and a LEv phase, that denoted the “lie-down” and “stand-up” types of adsorption, respectively, was used to describe this transition and a cusp, instead of a constant surface-tension region, was observed in the dynamic γ(t) curves for this transition. This suggested that, since the surface tension varied during the transition process, the newly identified LEh and LEv transition might not be the typical first-order type of phase transition.  相似文献   
292.
The purpose of this paper is to investigate the computer applications and analyses in industrial distribution design. First of all, we have to inquire into the design of graphic symbols and the drawing of a single-line diagram by taking advantage of AutoCAD software. Next, by employing DBASE III, the database for distribution apparatus is accomplished to integrate with the graphic information so that the distribution graphic information database is obtained. Then, we focus our attention on the applications of practical operation for a factory. Written in C language, the application programs include load flow calculation, voltage drop equation, grounding resistor selection, power factor improvement, wire selection, protective coordination display, and fault current computation. Finally, the linking of man-machine-interface and application programs can be accomplished through the modification of ACAD.MNU and ACAD.PGP of AutoCAD. Accordingly, an educational teaching software is developed to carry out a key-controlled industrial distribution system analysis  相似文献   
293.
This paper presents a new approach to identify fault types and phases. A transmission line fault classification method based on a radial basis function (RBF) neural network with orthogonal-least-square (OLS) learning procedure was used to identify various patterns of associated voltages and currents. The RBF neural network was also compared with the back-propagation (BP) neural network in this paper. It is shown that the RBF approach can provide a fast and precise operation for various faults. The simulation results also show that the proposed approach can be used as an effective tool for high speed relaying  相似文献   
294.
The micropositioning system using flexural bearing (e.g., for wafer steppers and coarse-fine positioning systems) is a system of infinite degrees of freedom. It is difficult to design a controller for the partial differential equation of the system directly. In this paper, a closed-form dynamics model is first developed using the assumed modes method and the least squares method. Then, a hierarchical neuro-fuzzy controller using backpropagation (BP) training algorithm is proposed for the precision control and active damping of the micropositioning system. Simulation results show that the suggested strategy can actively suppress the flexible vibration and have high positioning performance.  相似文献   
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