Improved band parameters for a simplified wide band cumulative absorption coefficient distribution model for H2O and CO2

An accurate and computationally efficient approach to evaluate wide band parameters with polynomial series for use in a simplified wide band cumulative absorption coefficient distribution, g(k), model is presented. The fitting coefficients are determined by a best fit with g(k) functions generated from the latest high resolution spectroscopic database. The approach significantly improves the prediction of the g(k) function over a wide range of temperatures from 500 to 2500 K, pressures from 0.01 to 1.0 atm, and all single bands of H₂O and CO₂. The root mean square error of the predicted absorption coefficient is below 25% except the single 4.3 μm band model. The approach also provides accurate calculations for the wide band absorptance, generally with differences below 7% when compared to benchmark results.     

Application of the Miller cycle to reduce NOx emissions from petrol engines

A conceptual analysis of the mechanism of the Miller cycle for reducing NO_x emissions is presented. Two versions of selected Miller cycle (1 and 2) were designed and realized on a Rover “K” series 16-valve twin-camshaft petrol engine. The test results showed that the application of the Miller cycle could reduce the NO_x emissions from the petrol engine. For Miller cycle 1, the least reduction rate of NO_x emission was 8% with an engine-power-loss of 1% at the engine’s full-load, compared with that of standard Otto cycle. For Miller cycle 2, the least reduction rate of NO_x emission was 46% with an engine-power-loss of 13% at the engine’s full-load, compared with that of standard Otto cycle.     

大洋多金属结核熔炼合金锈蚀工艺的研究

研究了大洋多金属结核熔炼合金锈蚀浸出分离除铁工艺。采用能明显加快锈蚀反应速度的高效添加剂，在最佳工艺条件下，于浓度为４５ｇ／Ｌ的稀盐酸介质中，鼓空气锈蚀－０．１８０ｍｍ合金粉末７ｈ，反应完全，有价金属Ｃｕ，Ｃｏ，Ｎｉ浸出率分别达９８．３３％，９７．８６％，９９．４６％，锈蚀液中铁为痕量，实现一步彻底分离。     

两种镜质体结构分析

应用傅里叶红外光谱、Ｘ射线衍射和电子顺磁共振分析方法，探讨了富氢镜质体与正常镜质体在化学结构上的差异性和随煤阶的变化规律．富氢镜质体比同煤阶的正常镜质体含有较多脂类结构，较少芳香结构．随煤阶增高，镜质体结构向芳构化作用增强的方向演变，面网间距、晶核高度、芳环层数、芳香度及自由基浓度等参数均呈现规律性变化．     

Morphology and kinetic study of the interfacial reaction between the Sn-3.5Ag solder and electroless Ni-P metallization

This work summarizes the interfacial reaction between lead-free solder Sn-3.5Ag and electrolessly plated Ni-P metallization in terms of morphology and growth kinetics of the intermetallic compounds (IMC). Comparison with pure Ni metallization is made in order to clarify the role of P in the solder reaction. During reflow, the IMCs formed with the Ni-P under-bump metallization (UBM) exist in chunky crystal blocks and small crystal agglomerates, while the ones with the sputtered Ni UBM exhibit uniformly scallop grains with faceted surfaces. The IMC thickness increases with reflow time following approximately a t^1/3 power law for both systems. The IMC growth rate is higher with the Ni-P UBM than the Ni UBM. The thickness of the Ni₃Sn₄ layer increases linearly with the square root of thermal aging time, indicating that the growth of the IMCs is a diffusion-controlled process. The activation energy for Ni₃Sn₄ growth in solid-state reaction is found to be 110 kJ/mol and 91 kJ/mol for the Ni-P and sputtered Ni UBMs, respectively. Kirkendall voids are detected inside the Ni₃P layer in the Sn-3.5Ag/Ni-P system. No such voids are found in the Sn-3.5Ag/Ni system.     

挠性多层板材料变形的原因及解决方法

本文介绍了挠性多层板在制造过程中产生变形的原因,以及由变形所引起的问题,并使用补偿的方法使问题得到初步的解决。     

基于PC平台的VoIP实现

本文提出了一种基于PC平台的VoIP软件的设计方案,并详细介绍了音频数据的传输、编解码、解压缩、打包以及拆包的VC程序设计过程.     

单向激励源在TD-BPM中的应用

把单向激励源应用到隐式时域光束传播方法(TD- BPM)中,结合交替方向隐式方法(ADIM)及Grank- Nicho-son差分原理,给出了单向激励源在隐式TD- BPM中的具体实现方法.通过该方法可以方便地得到各种有反射结构的反射场和总场,在模拟计算不连续界面的反射、透射问题中有重要的作用.通过几个基本问题得到了该方法的各种计算结果,验证了该方法的有效性