氯苯紫外光降解产物对生物过滤塔运行性能的影响

生物过滤技术对难生物降解VOCs的处理效果较差,构建紫外光降解-生物过滤联合处理工艺是解决难生物降解VOCs处理的一个有效手段.已有研究表明,紫外光降解预处理对氯苯生物过滤塔的去除性能有促进作用.为了考察紫外预处理对生物过滤塔的影响机理,本研究分别考察了氯苯紫外光降解主要产物氯酚、乙酸以及副产物臭氧对生物过滤塔运行性能的影响.研究结果表明,加入乙酸降低了生物过滤塔的氯苯去除性能,在增加喷淋量后去除性能有所恢复.加入邻氯酚使生物过滤塔的氯苯去除性能略有降低.臭氧明显促进了生物过滤塔的氯苯去除性能,当进口臭氧浓度在60～120mg.m-3时,氯苯平均去除率可由70%提高到90%以上.因此,臭氧是紫外预处理促进生物过滤塔运行性能的主要因素.     

基于生态安全的快速城市化地区空间冲突测度 ——以长株潭城市群为例

空间冲突是城市化过程中各种矛盾形成与激化的直接原因,是影响区域可持续发展的关键因素,合理测度快速城市化地区的空间冲突水平,对于优化区域发展模式、 避免区域生态风险具有重要意义。在利用遥感与GIS技术分析长株潭近年来空间格局变化的基础上,量化影响区域生态安全的空间外部压力值、 生态风险暴露值、 生态风险效应值3个因子,构建基于生态安全的空间冲突测度模型,对长株潭地区的空间冲突水平进行评估。研究表明:近年来长株潭地区的空间冲突作用强度总体呈现上升趋势,1993—2008年其冲突指数均值由0.264增长到0.323,且严重失控级别空间冲突的区域面积比例增幅最大,达1.07倍;不同空间类型的空间冲突强度不同,林地、 耕地的空间冲突水平相对较低,建设用地的空间冲突水平较高;城乡过渡地带是空间格局变化最为频繁、 空间冲突最为激烈的区域,其次是城市内部,农村地区的空间冲突强度远远低于城市。     

Ultrafine particle emission characteristics of diesel engine by on-board and test bench measurement

This study investigated the emission characteristics of ultrafine particles based on test bench and on-board measurements. The bench test results showed the ultrafine particle number concentration of the diesel engine to be in the range of (0.56-8.35) × 10⁸ cm^-3. The on-board measurement results illustrated that the ultrafine particles were strongly correlated with changes in real-world driving cycles. The particle number concentration was down to 2.0 × 10⁶ cm^-3 and 2.7 × 10⁷ cm^-3 under decelerating and idling operations and as high as 5.0 × 10⁸ cm^-3 under accelerating operation. It was also indicated that the particle number measured by the two methods increased with the growth of engine load at each engine speed in both cases. The particle number presented a "U" shaped distribution with changing speed at high engine load conditions, which implies that the particle number will reach its lowest level at medium engine speeds. The particle sizes of both measurements showed single mode distributions. The peak of particle size was located at about 50-80 nm in the accumulation mode particle range. Nucleation mode particles will significantly increase at low engine load operations like idling and decelerating caused by the high concentration of unburned organic compounds.     

建筑陶瓷碳计量与优化模型研究

采用投入产出分析方法和目标规划方法,以某建陶企业为代表,建立了建筑陶瓷产业投入产出模型及低碳优化模型,利用投入产出模型计量和预估了建筑陶瓷产业关键环节碳排放和产品碳足迹;应用低碳优化模型对建筑陶瓷企业的产品计划进行了低碳优化.结果表明,建筑陶瓷企业年二氧化碳排放量达182 543.9 t,单位产品碳排放量多于国外先进水平10%以上;影响建筑陶瓷产业二氧化碳排放的关键环节为烧成和喷雾干燥过程,烧成和喷雾干燥过程排放的二氧化碳占总排放的80%以上;3种建筑陶瓷产品中,坯砖、抛光砖、釉面砖的万平米产量碳足迹依次为150.2、168.0、159.6 t.建筑陶瓷企业经低碳模型优化后可以在保证同样利润的同时降低5.4%的碳排放,也可以在保证碳排放相同的条件下使利润提高5.6%.     

原子吸收分光光度法测定水中铅的不确定度评定

对GB/T 7475-1987《水质铜、铅、锌、镉的测定》〔1〕原子吸收分光光度法测定水中铅的测量不确定度进行了评定。通过测量重复性、滴定管、移液管、标准溶液浓度等影响测量结果的不确定度分量的分析和量化,求得水中铅测定结果的相对合成标准不确定度。     

环境地表γ计量率、工频电磁场和射频电场监测实验结果对比分析研究

本文通过两实验室针对环境地表γ计量率、工频电磁场和射频电场仪器对比实验,并对结果进行了统计检验。分析结果表明,两者监测数据无显著差异。     

应用地磁场的弹体飞行姿态测量方法研究

常规弹药的简易制导化是常规弹药改造的一个重要途径,是目前研究的热点之一,可以在低成本下大大提高常规弹药的精度,弹道修正弹是其中的一个重要发展方向,而弹体姿态实时测量是其中的一项关键技术。介绍了弹体姿态测量中基于地磁场的姿态测量方法,将其分为组合姿态测量和单矢量测量,并对测量方法做出了分析,阐述了应用地磁场的姿态测量的重要意义。     

Evaluation of two models of a slipmeter

The aim of the study was to compare the performances of the Brungraber Mark II (BM II) and Mark III (BM III) slipmeters. Friction measurements with the two slipmeters were conducted in a laboratory using four footwear materials, four floor types, and three surface conditions. Both the coefficient of friction (COF) values obtained with the slipmeters and the force platform-based COF values were measured. The COF measured with the BM II was slightly higher than that measured with the BM III with a R² of 0.83. A comparison of the averaged normal force between the two slipmeters showed that the BM II generated a significantly higher normal force than the BM III at a low COF and the difference of the normal force between the two slipmeters decreased when the COF value was increased. The regression analysis results in this study showed that the force platform-based COF values were closer to the COF values obtained with the BM III than with the BM II. The R² values for the regression model between the COF values obtained from the slipmeter and the force platform were 0.90 and 0.79 for the BM II and BM III, respectively.     

热真空设备中与温度相关的试验技术探讨

以RZHM-1400-AB型热真空试验箱为实例,简述设备主要工作原理。强调其温度传递方式及航天产品在热真空试验中温度参数的重要性。以无数试验数据为依据,着重论证何种类型测温传感器与实际设备相匹配,同时论证选取何种外形的测温传感器为最佳温度测量工具。同时,进一步介绍几种在热真空试验中使用这些测温传感器的方法,以减少不必要的人为测量误差。     

水质总氮测定中的有关问题探讨

对总氮测定中的一系列影响因素，诸如实验用水，器皿的洗涤，实验室环境试剂的提纯、配制和保存，消解温度、压力和时间的控制，以及高氨氮水样中的总氮测定、总氮、总磷的同时测定和其他有关的问题，作了较为详细的探讨，并提出了相应的解决办法。