EGR和催化转化净化汽油车排气的试验研究

在发动机排气再循环和催化转化机理与车用汽油机排气特性研究的基础上，本文通过对车用汽油机装上EGR的催化转化装置后，在发动机台架上进行中低转速下的发动机负荷特性试验，探讨在有无EGR时对催化转化净化效果的影响。     

Energy Conversion and Temperature Dependence in Ozone Generator Using Pulsed Discharge in Oxygen

A detailed reaction kinetic model consisting of 10 species and 63 reactions is developed to investigate the energy conversion and temperature dependence in an ozone generator using oxygen pulsed discharge. The energy conversion ratios of total electric energy converted into reaction heat, heat carried by gas and heat loss to ambient, namely η_reaction, η_gas and η_loss, are obtained for the first time. The ratio of reaction heat η_reaction decreases substantially with increasing specific energy and inlet gas temperature, which represents how much energy is utilized effectively to synthesize ozone. Correspondingly, η_loss and η_gas increase gradually. η_reaction declines from 55.4% to 27.7% at inlet gas temperature of 298 K when specific energy changes from 0.06 J/cm³ to 0.78 J/cm³. The detailed reaction pathway including the degree of transformation among species for ozone formation is also obtained via kinetics simulation. Meanwhile, sensitivity analysis and rate-of-production analysis for the four most important species O₃, O, O(1D) and O₂(b¹∑) obtained from the reaction pathway are executed to understand quantitatively the temperature dependence of sensitivity coefficient and production rate for each individual reaction. The production rate of ozone via the most important ozone generation reaction O+O₂+O₂ = > O₃+O₂ increases linearly with the increase of gas temperature, as well as the destruction rates of ozone via the most important ozone decomposition reactions O₃+O₃ = > O₂+O₂+O₂ and O₃ + O = > O₂(b¹∑)+O₂.     

Recovery of nano-calcium fluoride and ammonium bisulphate from phosphogypsum waste

ABSTRACT

The production of phosphoric acid generates an enormous amount of phosphogypsum with emission of toxic fluorine acid gas. To remedy these environmental problems, a novel and a simple procedure permits converting phosphogypsum waste by recycled fluorine acid into valuable products. The obtained results confirm the efficiency of this procedure, which synthesises at room temperature the calcium fluoride in the form of nano-crystalline powder and the ammonium bisulphate salt from the exact stoichiometric proportions of phosphogypsum, hydrofluoric acid and ammonia. The total conversion of phosphogypsum is achieved after reaction time equal to one hour and a half. Generally, this novel procedure offers not only a solution for reducing phosphogypsum waste and fluorine gas emission, but also gives rise to valuable products, useful to industry and agriculture.     

Modification of X-ray Generator by Energy Reusing

X-ray is an important tool for charactering and analyzing materials. However, current X-ray generation is cost with low efficiency. For X-ray tube, which is mostly used in laboratories, only has an energy usage of 1% with all other energy dissipated into tremendous heats, and it needs continuous cool water flows to cool down the cathode. It generates X-ray by the bremsstrahlung of high energy electrons bombarding on the cathode target, the bremsstrahlung would contain X-ray with sufficiently high energy of the electrons. But most part of the electron energy becomes heats. In order to generate X-ray more cheaply with higher efficiency, methods about reusing the released heats during the working of the X-ray tube are brought up. Mimicking the photovoltaic effect, nonequilibrium carriers could also be injected via thermion emission when heating a metal, such injection is same to that of photonic injection which produces electromotive in a photovoltaic cell. In a photovoltaic cell the electron-hole pair generated by incident photons are nonequilibrium carriers that causes electromotive, while the thermion emission creates such electron-hole pairs via thermal excitation. Connecting metals suitable for thermion emission from the cathode into the p-n junction so that thermions as nonequilibrium carriers can be well injected into the p-n junction when the metals are heated by the cathode, with Thomson effect which enhances such injection, a thermal voltaic cell can be constructed and it can produce electricity only by heating the metals outside. Applying such thermal voltaic cell into current X-ray tube, it would produce electricity while absorbing the tremendous heats emerges when X-ray tube is working. Water flows are still used to control the temperature, but letting them boiling to keep the cathode at a temperature best for thermal voltaic cell, and the vapor may be used to drive a mini thermal power plant. In this way, the energy usage could be modified to a higher proportion. Stepwise up-conversion is possible to generate X-ray more cheaply but there are no suitable materials so far.     

Conversion of electric heating in buildings: An unconventional alternative

To decrease the electric energy used for heating buildings it has become desirable to convert direct electrical heating to other heat sources. This paper reports on a study of the possibility of using an unconventional method for conversion to avoid installing an expensive hydronic system. The conversion method combines the ventilation and heating systems and uses air instead of water for distribution of heat within the building, taking advantage of thermal forces and the special properties of gravity currents. Full-scale tests have been carried out in a test apartment inside a laboratory hall where the conditions could be controlled. Temperatures and efficiency of ventilation have been measured to ensure that the demands with respect to thermal climate and air exchange were fulfilled. The results show that it is possible to use the method for heating and ventilation when converting the heating system, but further work has to be done to develop a detailed solution that works in practice.     

EPS2000和AutoCAD平台下图形文件的无缝转换

探讨了通过EPS2000的模块设置将图形件转换成AutoCAD平台下的图形件的方法，并应用适当的方法和程序处理来实现测图系统问图形件的无缝转换，达到资源合理共享的目的。     

铝合金的表面保护层

传统的秀铬酸盐对铝合金进行表面抗蚀处理存在各污染问题,有许多研究工作在努力开发代铬无毒或低毒的表面保护层,其中有化学方法,也有物理方法,本文中对有关研究工作做了概述。     

交流变频调速技术在工业锅炉风机中的应用

本文针对江西洪都钢厂锅炉原系统存在的问题,提出了利用交流变频调速技术改造锅炉鼓风机电控系统的设计思路,简单介绍了交流变频调速技术在工业锅炉风机中的应用情况,指出了实际应用的节能效果。     

电子能量损失符合谱仪的多路TDC系统

介绍了用于原子分子实验的电子能量损失符合谱仪中的多路TDC系统。按照谱仪的飞行时间质谱仪的需要,设计了一起多停式的多路TDC。该系统已在原子分子实验室的电子能量损失符合谱仪上调试成功。     

钢－混凝土组合梁计算程序

针对当前钢－混凝土组合梁设计主要采用人工计算的弊端，提出ＣＰＳ计算程序，在计算荷载效应时采用了有限元、离散元等力学方法和优化设计手段。实际应用证明：程序设计合理，是解决复杂多变的设计计算问题的有效方法。