语音时域分割研究

在语音时域挑选剩余可懂度低的可用置换集合,置换集合是语音TDS系统中不可缺少的重要环节,本文给出了可用置换选取的条件、客观评价标准和方法。     

Pore size control of porous silica by sol-gel process

Porous silica glass was prepared by sol-gel process from tetraethoxysilane (TEOS). The effects of solvents (water, ethanol), drying condition, heat treatment temperature on specific surface area and pore size distribution of porous silica were investigated. Gelation process accelerates with an increase of H₂O content, while retards with the increase of ethanol amount. Structure changes during heat treatment were studied by means of DTA, XRD. TEM micrographs show that the gel particles shrink after heated at 500°C, thus the average pore size decreases.     

Finite Element Analysis of a Moving Boundary Value Problem

A finite element formulation and the solution of a set of nonlinear coupled heat and mass transfer equations for a two-phase system with a moving evaporation interface is presented. The interface condition takes into account the moisture transfer balance at the moving boundary. The finite element results were compared with existing results for a single phase system for model validation. In the two-phase system, the movement of evaporation front has an appreciable effect on the temperature and moisture distribution inside the porous medium during drying. The effect of the nondimensional heat of vapourization parameter γ on the evaporation front, temperature and moisture distribution in porous medium was studied. The higher the value of γ, the slower is the movement of the evaporation front. The temperature decreased and the moisture content increased as the nondimensional vapourization parameter γ increased. This model has potential applications in studying the heat and mass transfer characteristics in food and biomaterials.     

The influence of the alloying elements upon the transformation kinetics and morphologies of ferrite plates in alloy steels

A series of Fe-C-X and Fe-C-X₁-X₂ alloys in which X, X₁ and X₂ either raise or depress the activity of C iny were investigated by autodilatometer, optical microscopy, and transmission electron microscopy (TEM) to reveal the relations among the chemical composition, transformation kinetics, and morphology of ferrite plates. The incubation time of austenite decomposition at the nose temperature in the time-temperature-transformation (TTT) diagrams, the concentration of C in y in contact with theα/gg boundary, and the growth rate of ferrite were evaluated to estimate the magnitude of the solute drag-like effect (SDLE) for the different alloying elements used. All the results are consistent qualitatively with the SDLE hypothesis. This article is based on a presentation made at the Pacific Rim Conference on the “Roles of Shear and Diffusion in the Formation of Plate-Shaped Transformation Products,” held December 18-22, 1992, in Kona, Hawaii, under the auspices of ASM INTERNATIONAL’S Phase Transformations Committee.     

Mobility modeling, location tracking, and trajectory prediction inwireless ATM networks

Wireless ATM networks require efficient mobility management to cope with frequent mobile handoff and rerouting of connections. Although much attention has been given in the literature to network architecture design to support wide-area mobility in public ATM networks, little has been done to the important issue of user mobility estimation and prediction to improve the connection reliability and bandwidth efficiency of the underlying system architecture. This paper treats the problem by developing a hierarchical user mobility model that closely represents the movement behavior of a mobile user, and that, when used with appropriate pattern matching and Kalman filtering techniques, yields an accurate location prediction algorithm, HLP, or hierarchical location prediction, which provides necessary information for advance resource reservation and advance optimal route establishment in wireless ATM networks     

A study on the anodic protection of Titanium evaporators in Al2(SO4)3 solution

The feasibility of the anodic protection of titanium evaporators in Al₂(SO₄)₃ solution was studied by the measurement of polarization curves, weight loss, solubility of passive film and AC impedance. The protection parameters and efficiency were determined. In addition, the practical technology of anodic protection was studied by screening reference electrodes and auxiliary cathodes. Throwing power was also measured. Four rows of tube-type evaporators of titanium have been anodically protected in situ. Field tests lasting more than one year show satisfactory results.     

A maximum torque control with a controlled capacitor for asingle-phase induction motor

This paper presents a new method to achieve a maximum torque for a single-phase induction motor. An AC adjustable capacitor using an electronic switch in parallel with a capacitor is proposed. The capacitor is short-circuited in a different period by an electronic switch during each cycle to vary the effective value of the AC capacitor. Two new optimization algorithms, which obtain a maximum starting torque by adjusting the effective capacitor, are proposed. No starting capacitor or centrifugal switch is used here. A theoretical analysis, and simulated and experimental results are presented in this paper     

Role of RE and Mg on Graphitization of Spheroidal Graphite Malleable Cast Iron

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Results of initial surgery and adjuvant chemotherapy in treating small-cell lung cancer

The changes in the intestinal mucosal permeability were observed by quantitatively assessing plasma to luminal clearance of 99mTc-labeled DTPA, and the influence of platelet activating factor (PAF) on it was investigated. The results showed that intestinal permeability was significantly elevated after severe burn and was positively correlated with increase in PAF in the intestinal tissue (r = 0.94, P < 0.01). PAF antagonist therapy could significantly attenuate postburn intestinal mucosal permeability. It is concluded that PAF is one of the important factors causing increased intestinal permeability after severe burn.