A NaI activation method for the measurement of the weak thermal neutron field around the MEG experiment

A precise measurement of the thermal neutron flux (and an approximate measurement of the non-thermal neutron flux), associated with the high intensity stopping μ⁺ beam (≈) of the MEG experiment, was studied by measuring the delayed radioactivity of an activated NaI detector. This passive method provides a high sensitivity and allows the neutron flux determination at all locations, even in regions of high magnetic field. We present and discuss the results.     

正电子直线加速器俘获节加速场梯度对俘获率的影响

一、引言在正电子直线加速器中,正电子在靶上生成,经过一段匹配段,进入加速管。通常称这根加速管为俘获节。俘获节的加速场梯度如何影响正电子的俘获率,是在加速器设计和运行过程中很感兴趣的一个问题。所谓俘获,指的是,粒子在横向不碰到系统管壁,在纵向聚到一定相位范围,且在俘获节末端的能散度不超过某个限度。这样,正电子在以后的加速过程中,一定相宽内粒子数的多少将决定最终束流能谱的好坏。     

基于RTP协议的视频实时采集与传输的研究

分析了实时通信协议RTP及其控制协议RTCP,构建一个基于RTP协议的采集传输系统,能够实时采集视频数据、编码并通过网络传输。     

延迟捕获功能的硬件研究设计与应用

本文介绍了延迟捕获功能的设计思想和具体电路的实现,并将延迟捕获方法实际应用到血液粘度测试仪器的切变率测量上,经实际应用表明具有软硬件结构简单、使用灵活、精度高、运行可靠等优点,对于一些在嵌入式应用中需要测量转速指标时,可谓一种良好的方法。     

Efficiency of an Integrated Gasification Combined Cycle (IGCC) power plant including CO2 removal

This study is devoted to technical evaluation of a carbon dioxide removal in an existing Integrated Gasification Combined Cycle (IGCC) plant. This IGCC case is based on an oxygen blown entrained flow gasifier operating at 27 bar, the removal of acid gas (H₂S) is performed with MDEA unit, the efficiency of this IGCC is 43% based on the low heating value (LHV) of coal. A carbon dioxide separation unit conveniently integrated in a pre-combustion separation process is chosen, in order to take advantage of the high pressure of the gas. The methanol process for carbon dioxide removal is integrated downstream the existing desulfuration unit, and after a CO shift conversion unit. In this study, the integration of the CO₂ capture process to the IGCC is simulated as realistically as possible. The design parameters of both the gas turbine (the turbine inlet temperature, compressor pressure ratio, reduced flow rate) and the steam turbine (Stodola parameter) are taken into account. Maintenance of low _NOx${\mathrm{NO}}_x$ production in the combustion chamber is also considered. The production of _NOx${\mathrm{NO}}_x$ is supposed to be influenced by the low heating value of the gas which is maintained as low as for case of the synthesis gas without CO₂ capture. Thus the choice is made to feed the gas turbine of the combined cycle with a diluted synthesis gas, having similar low heating value than the one produced without the CO₂ capture. Plant performances for different conversion and capture rates are compared. A final optimized integration is given for 92 mol% CO conversion rate and 95 mol% CO₂ absorption rates, a comparison with former studies is proposed.     

三维人体自动测量技术综述

详细介绍了有关三维人体自动测量的现状、主要过程、应用、分类及各种测量方法的原理和特点,并讨论了各种测量方法的利弊,指出了目前制约三维人体测量技术发展的主要因素,最后提出了三维人体自动测量下一步的发展趋势。     

计算机图像采集装置在锅炉空气动力场试验中的应用

基于计算机技术和CCD摄像机技术,设计了一种用于电站煤粉锅炉空气动力场试验的图像采集装置。介绍了装置的硬件构成、工作原理、主要性能及应用情况。     

Immobilization of carbonic anhydrase for facilitated CO2 capture and separation

Carbonic anhydrase (CA) as a typical metalloenzyme in biological system can accelerate the hydration/dehydration of carbon dioxide (CO₂, the major components of greenhouse gases), which performer with high selectivity, environmental friendliness and superior efficiency. However, the free form of CA is quite expensive (~ RMB 3000/100 mg), unstable, and non-reusable as the free form of CA is not easy for recovery from the reaction environment, which severely limits its large-scale industrial applications. The immobilization may solve these problems at the same time. In this context, many efforts have been devoted to improving the chemical and thermal stabilities of CA through immobilization strategy. Very recently, a wide range of available inorganic, organic and hybrid compounds have been explored as carrier materials for CA immobilization, which could not only improve the tolerance of CA in hazardous environments, but also improve the efficiency and recovery to reduce the cost of large-scale application of CA. Several excellent reviews about immobilization methods and application potential of CA have been published. By contrast, in our review, we stressed on the way to better retain the biocatalytic activity of immobilized CA system based on different carrier materials and to solve the problems facing in practical operations well. The concluding remarks are presented with a perspective on constructing efficient CO₂ conversion systems through rational combining CA and advanced carrier materials.     

.NET平台下开发自动捕获屏幕程序的研究

介绍了.NET平台下开发Windows服务程序的基本原理,并以开发自动捕获屏幕程序为例,深入探讨了服务程序的开发过程,同时提供了重要的样例代码,对相关的工程实践有较大的实用价值和借鉴意义。     

Flue-gas cooling in post-combustion capture plants

In the present paper, the results of an activity performed in the ongoing EU project, CESAR (CO₂ Enhanced Separation and Recovery) are presented. In the CESAR project five different baseline power-plants are considered. These consist of two lignite- and two bituminous-coal fired plants while the fifth is fuelled by natural gas. Part of the design work relates to identifying the benefits attainable through appropriate integration of flue-gas cooling to these baseline power-plants. It is shown that the approximate reductions in capture-cost for the studied (optimal) cases are of the order of 20% for the lignite-coal cases, 10% for the bituminous coal cases and 13% for the natural gas case using MEA as solvent. The reductions are basically due to the inclusion of pre-cooling. However, a positive effect of inter-cooling was also found for all the coal cases, while a negative cost effect was found for the natural gas case. For piperazine as solvent the positive effect of cooling was much more pronounced than for MEA and especially the effect of inter-cooling.