MOS器件的热载流子效应

热载流子效应产生的原因，首先是在沟道强电场中形成迁移率偏低的热载流子，然后由于碰撞电离而使热载流子大量增加。热电子和热空穴能够越过界面势垒向栅氧化层发射。进入栅氧化层的热载流子，或者穿透氧化层，或者造成随时间而增加的界面态，或者造成载流子陷阱。热电子或热空穴也可以受结电场的作用而进入衬底。抑制热载流子效应的方向，一是在沟道两侧制作轻掺杂区，以降低沟道电场强度；二是对栅氧化层进行氮化处理和提高氧化温度，以改善氧化层的质量，增强抗热载流子效应的能力。     

Hot deformation behaviors of WE71 alloy under plain strain compression at elevated temperature

Hot deformation behaviors of WE71 (Mg–7Y-1Nd-0.5Zr) alloy was investigated by plain strain compression tests conducted at temperatures ranging from 350 °C to 500 °C and strain rates varying from 0.01 s^-1 to 10 s^-1. Results show that the hot deformation of WE71 was accompanied by the precipitation of rich Zr phase with granular shape and block-shaped phase rich in element Y. When deformed at low temperature and high strain rate, the softening behavior of the alloy was synergically determined by shear bands propagation, adiabatic heating, twinning formation and dynamic recrystallization (DRX). For the conditions of high temperature and high strain rate, DRX was the major softening mechanism while the formation and annihilation of extension twinning resulted in a special flow curve characteristic at the strain of around 0.3. According to the microstructural observations, it can be concluded that the irregular flow curves of WE71 alloy during plain strain compression process are mainly ascribed to shear bands propagation, adiabatic heating, twinning formation and DRX.     

普碳热轧带钢力学性能回归方程及其应用

确定了厚度为2.75mm普碳热轧带钢σ_b与碳、硅、锰含量的定量关系,得到3σ_b与碳、硅、锰含量的定量关系,得到了σ_b与碳、硅、锰含量呈显著的线性回归方程。     

热锻模表层热影响与磨损形式

本文研究了汽车转向节热锻模型腔表层因热影响所引起的显微组织变化与磨损形式.通过金相观察、扫描电镜分析及显微硬度测定,结果表明模具在高温、巨烈摩擦力及冷热应力的循环作用下,型腔表层出现了两种与原始显微组织不同的白亮层,且在不同的白亮层区域内出现了不同形式的磨损.     

层流冷却系统的自动化控制

介绍了某现代化钢铁企业热轧厂层流冷却系统自动化控制的系统设计，自动控制策略、模型以及控制系统投入在线运行后的实际控制结果和存在问题。并在此基础上进行了分析和改进，实际控制结果表明，通过对设计的应用软件的适当改进和模型系数的优化确定，可以把取温度控制在要求的范围，设计的层流冷却控制系统基本上能满足生产和工艺的要求。     

运用价值工程原理改进酚醛树脂砂覆膜工艺

榆次液压元件厂(下简称榆液厂)铸造车间对液压铸件复杂砂芯的生产,多年来采用冷法覆膜酚醛树脂砂.原配砂工艺复杂,周期长,成本高,满足不了生产需要,因而希望试验出一种既能满足工艺要求而又降低成本、简化生产工艺过程的工艺方案来.为此,我们运用价值工程原理进行研究.     

Hot compressive deformation behaviors of Mg–10Gd–3Y–0.5Zr alloy

In this paper, the hot compressive deformation characteristics of a Mg–10Gd–3Y–0.5Zr(GW103K) alloy have been investigated by isothermal compression test at the temperature range of 350–450°C and strain rate range of 0.0001–0.1s~(-1). True stress–strain relationships at various strain rates showed the typical strain hardening and softening stage which is indicative of dynamic recrystallization during deformation. The results showed that the peak stress was obviously dependent on temperature and strain rate. A constitutive equation to describe the deformation process was established based on the hyperbolic sine function. The stress exponent n and apparent activation energy Q were determined to be 3.018 and 203.947 k J/mol, respectively. Microstructure investigation showed that dislocation slipping was the dominant deformation mechanism during the hot deformation at all conditions. However, at the temperatures lower than 400 °C and strain rates higher than 0.01 s~(-1), twinning was observed to be activated, which indicated another deformation mechanism. Dynamic recrystallization and dynamic precipitation were found to occur simultaneously under such deformation condition.     

广元剑门关热矿泉水产出特征与成因探讨分析

本文就剑阁县剑门关热矿泉水的产出条件进行了阐述，对其形成的地质条件和水文地质条件进行了详细分析，对水质进行了化验分析，对其成因进行了探讨，为寻找相同类型的矿采水具有一定的参考作用和借鉴意义。     

高考复读热的原因及影响分析

近年来,高考复读现象逐渐转变为病态的高考复读热现象,该现象的出现必然尤其客观和主观原因,同时它也产生了一定的消极和积极的影响。本文拟就分析上述两个方面的问题。     

Prediction of hot deformation behavior in Ni-based alloy considering the effect of initial microstructure

High temperature heat treatments were conducted for as-cast N08028 alloy to obtain various microstructures with different amounts of σ-phase,and then hot compression tests were carried out using Gleeble-3500 thermo-mechanical simulator in deformation temperature range from 1100 to1200 ℃ and strain rate range from 0.01 to 1 s-1. For the same initial microstructure, the flow stress was observed to increase with increasing the strain rate and decreasing the deformation temperature, while for the same deformation condition, the flow stress was found to increase with increasing the amount of σ-phase in the initial microstructure. Moreover, dynamic recrystallization was found to be the main dynamic soften mechanism. On this basis, Arrhenius-type constitutive equations and artificial neural network(ANN) model with back-propagation learning algorithm were established to predict hot deformation behavior of the alloy. Furthermore, the parameters of constitutive equations were found to be dependent on the initial microstructure, which was also as one of the inputs for the ANN model. Suitability of the two models was evaluated by comparing the accuracy, correlation coefficient and average absolute relative error, of the prediction. It is concluded that the ANN model is more accurately than the constitutive equations.