H-ZSM-5分子筛吸附-氧化NOx的研究

针对湿法脱硫后船舶尾气特点,考察了3种不同硅铝比的H-ZSM-5分子筛对船舶脱硫后尾气中NO_x的吸附-氧化过程及其影响因素,并采用TPD研究了干气下不同硅铝比的分子筛吸附饱和后的脱附情况.结果表明:干气条件下,硅铝比低的分子筛具有较好的吸附效果;硅铝比高的分子筛具有较好的抗水性,但从干气到饱和湿度下,硅铝比为300的分子筛的NO氧化率从36%降至18%;干气下,低温有利于分子筛的吸附-氧化;分子筛用量增加能够增加其对NO_x的吸附效果和氧化效果.TPD结果表明:NO和NO2共吸附在分子筛上,3种分子筛中脱附出的NO_x中NO2均占脱附总量的80%以上,但在600℃时,NO_x在分子筛上脱附仍不完全.     

水质基准方法学中若干关键技术探讨

我国正在开展系统的水质基准研究,对发达国家的水质基准理论和技术处于学习和研究阶段. 物种敏感度分布分析、“最少毒性数据需求”以及基准的修正是水质基准推算中的若干关键技术. 以氨氮水生生物基准为例,对这些关键技术进行了研究与探讨,提出在我国本土生物毒性数据缺乏的情况下可在种的水平上对水质基准进行推算. 另外,可先利用全部生物的毒性数据进行物种敏感度分析,确定需重点获取的敏感生物类群的毒性数据,再用于基准推算,有望降低推算过程中对毒性数据量的需求. 最后,基于中美生物物种分布的差异,借鉴美国修订国家水质基准的水效应比法,提出利用生物效应比法对美国国家水质基准进行修订以获取我国水质基准.      

碳汞比对燃煤烟气中Hg脱除影响的实验研究

利用吸附反应器和袋式除尘器联合脱汞系统,研究了活性炭喷射对模拟烟气中元素汞的脱除影响。实验表明,吸附反应器对元素汞的脱除起主要作用,并且脱汞效率随碳汞比的增加而提高;碳汞比的变化对除尘器的脱汞效率影响不大。在碳汞比为4 000、6 000、8 000下,系统的脱汞效率分别为39.9%、42.5%、47.3%。实验同时探讨了除尘器滤袋上粉尘层的存在对脱汞效率的影响,结果表明:在表面过滤速度为0.98 m/min的实验条件下,在碳汞比为4 000、6 000、8 000下,粉尘层的脱汞效率分别为:3.65%、3.20%、3.66%。     

蒙特卡洛法计算750kV输电线路绕击跳闸率的研究

利用GDS多功能三轴仪,通过控制土样应变增量比开展了饱和砂土部分排水三轴试验;利用超静孔隙水压力、有效应力路径和应力应变关系三方面的实验结果,研究了饱和砂土的渐近状态特性。研究表明,控制应变增量比为常数进行常规三轴加载时,饱和砂土的有效应力比也趋于某一常数,形成渐近状态,且渐近状态应力比随应变增量比的增大而减小。基于土的剪胀特性给出了渐近状态形成的物理机制,并给出了北京某砂土在部分排水条件下渐近状态应力比的试验结果。     

Performance of an ANAMMOX reactor treating wastewater generated by antibiotic and starch production processes

A pilot-scale anaerobic ammonia oxidation (ANAMMOX) reactor was used to treat mixed wastewater resulting from a chlortetracycline and starch production process. The results, collected over the course of 272 days, show that the ratio of influent ammonium to nitrite, pH, and temperature can all affect the efficiency of nitrogen removal. The ratio of influent ammonium to nitrite was maintained at about 1:1 at a concentration below 200 mg·L^-1 for both influent ammonium and nitrite. The total nitrogen (TN) loading rate was 0.15–0.30 kgN·m^-3·d^-1, pH remained at 7.8–8.5, and temperature was recorded at 33±1°C. The rate of removal of ammonia, nitrite, and TN were over 90%, 90%, and 80%, and the effluent ammonium, nitrite and TN concentrations were below 50, 30, and 100 mg·L^-1.     

小震震源机制P轴取向的预报应用

采用Snoke的振幅比方法,利用江苏台网和山东台网记录到的数字化波形资料,计算了发生在江苏及其附近地区的33个地震的震源机制解,并由此计算了其相应的P轴取向。结果表明:南黄海北部凹陷地区M_L5.1地震发生前2个月内、长江口地区显著小震群发生之前2个月内,在震中所在区域的附近地区有震源P轴取向小于100°的异常地震发生;盐城附近及其近海海域在本文研究的时段内未曾出现震源P轴取向小于100°的地震,该区域也没有发生中强地震或显著小震群事件。由此说明震源P轴取向具有一定的短临前兆意义,但这种情况与大地震事件所表现出来的规律并不完全相同。茅山断裂附近地区出现的2次震源P轴取向小于100°的事件与该地区重力异常结果是一致的,说明2002年前后茅山断裂曾活动过。     

分层抽样法在实验室废液量统计中的应用

实验室废液由于受实验室性质和科研课题数量的影响,其排放源分散,废液排放周期不定,排放水量也无规律性;因此要对一个城市和一定区域实验室的废液排放量进行准确统计监管非常困难.本文采用分层抽样中的比率估计法SRE对某城市实验室废液进行了统计.统计结果显示,该城市科研实验室废液排放总量为107.8 T,统计误差为10.04 T.实验室间的差异以及调查统计的准确性是造成误差的主要原因.该方法用于实验室废液的统计能够反映实际的废液排放情况,适合于环保管理部门用来对实验室废液进行监管.     

电炉粉尘高效利用的实验室研究

电炉炉尘中富含Fe、Zn、Pb等元素,简单地将这些炉尘倾倒野外或填埋处理,由于粉尘中Pb等有毒元素会被雨水浸出,严重污染水土资源.而直接返回高炉炼铁,Zn在高炉内氧化富集则会缩短炉衬寿命、堵塞煤气管道.为减少电炉粉尘对环境的污染,实现其高效利用,采用含碳球团焙烧还原法处理该类粉尘.通过考察温度、时间等工艺因数的影响,得到了焙烧还原法合理工艺条件:碳过量系数为0.8～0.9、还原温度1 150℃、还原时间50 min.还原后的球团为半金属化球团,其全铁含量为67%左右,最高达69.8%;金属铁含量为63%左右,最高达66.5%;单个球强度在6 kN左右;收集所得氧化锌粉含ZnO 80%左右,初步实现了电炉粉尘的高效利用.     

Relative density of finds for assessing similarity-based maps of orchid occurrence

Similarity-based mapping of the expected distribution of 10 orchid species was conducted in a study area covering 300 km² in south-eastern Estonia. The observation track and species finds were recorded during fieldwork. Absence locations were generated on the line of observation track. Both presence and absence sites having an in-between distance of at least 100 m were used as training data. Expected presence/absence of a species was calculated according to similarity between the predictable location and selected observations (examples) of presence and absence sites. For each species, the machine learning system identified the best predictive sets by selecting the most useful variables out of 136 map and remote sensing features. Similarity-based estimations were evaluated both by training fit and by independent verification data. Reliability of the predictive maps was expressed also by usefulness ratios—the densities of validation find sites (1) in the predicted presence area relative to the density of those in the predicted absence area, and (2) relative to the share of the observation track in the predicted presence area and in the predicted absence area. The predictive mapping was most efficient for Dactylorhiza incarnata, D. russowii, Epipactis palustris, and Goodyera repens. We conclude that the profound coverage of observations on any larger area is unrealistic and the reliability of similarity-based predictive maps depends on the representativity of existing records relative to the diversity of the study area. The investigation showed that the studied species are much more common in nature than the records in the national database indicate.     

确保地表建筑物安全矸石充填开采原料配比及充填量的确定

为确定某矿的矸石充填开采过程中最优充填材料配比和最佳的矸石充填量。设计了一种新型的矸石压缩模具,应用该模具和YE-200A液压试验机对十种不同粒径配比的矸石进行压缩试验,得出均匀配比的矸石为最优充填配比。采用最小二乘法拟合的数学模型,确定了均匀配比矸石充填材料与压力的变化规律。最后推出了均匀配比的矸石充填高度与采厚、顶板允许下沉量及顶板压力的函数关系。