新型烟气冷凝节能与脱硫装置研究

烟气冷凝节能与脱硫装置是适用于燃油燃气锅炉的新装置。本文介绍了该装置节能及脱硫的基本原理,利用81.4KW天然气锅炉实验系统对装置的传热和脱硫特性进行了研究。实验表明,该装置提高锅炉效率为3％-8％,脱硫效率为20％-40％。     

垃圾分选设备及垃圾处理技术展望

我国是人口大国 ,随着人民生活水平的不断提高 ,现有的垃圾处理技术已逐渐不能适应产量日益增长与成分不断复杂化的垃圾处理的需要 ,垃圾处理急需一场革命性的变化 ,必须摆脱现有城市垃圾处理三大方法面临的技术上难以避免的弊端和“阴影”。也就是说 ,垃圾处理应该从垃圾分选设备技术整体创新入手 ,引入一整套的垃圾机械处理联合装置及各种新型的联合处理方法 ,使垃圾处理成本大大降低 ,从而产生一次历史转折性的突破 ,带动和实现垃圾处理的产业化。为了达到这一目标 ,对垃圾处理需要重点解决的技术难关进行了探讨与展望     

大气颗粒物上多环芳烃的识别和源解析的进展

本文对当前大气颗粒物上ＰＡＨｓ的识别和源解析的定量及定性和半定量的方法进行了综述，定性及半定量方法简便易行，但误差大；化学质量平衡法结果较准确具体，但ＰＡＨｓ会发生化学反应而降解，并且没有各种燃烧源较完整的ＰＡＨｓ成份谱，这已成为ＣＭＢ广泛推行的障碍；多元统计方法不考虑ＰＡＨｓ的降解，但要求数据量大，国内外的科学工作者用不同的方法和手段，使ＰＡＨｓ来源的识别和源解析工作有了一定进展。     

城市室内环境多环芳烃污染与源的相关性

本实验选择了天津市４类典型室内环境和２处室外对照点，共１９个采样点。现场采样测定了１０种ＰＡＨｓ组成含量。结果显示，室内燃煤和室内吸烟是室内环境中多环芳烃排放的主要污染源。同作为对照的室外大气中多环芳烃组成和含量进行了对比，研究了室内环境不同污染源排放多环芳烃组成和含量的特征性。提出了室内燃煤污染同燃煤型室外大气源排放多环芳烃具有相似组成含量特征，而室内烟草烟雾污染源的多环芳烃组成含量特征则与室外     

Distribution normality of pH and H<Superscript>+</Superscript> activity in soil

Soil pH, a log-transformed form of hydrogen ion (H⁺) activity, is often used for various statistics. However whether soil pH meets the requirement of distribution normality for statistical analyses is unknown. We studied the statistical suitability of both soil pH and H⁺ activity by examining their distribution normalities. Results show that the variability of H⁺ activity is higher and its distribution is skewer, which is significantly different from the normal and soil pH, regardless of soil conditions and analytical methods. Here we demonstrate that soil pH is more appropriate than the H⁺ activity for performing statistical analysis in terms of distribution normality.     

邻苯二甲酸二丁酯对大型蚤(Daphnia magna)的毒性作用研究

本研究选用大型蚤(Daphnia magna)作为实验生物,研究了邻苯二甲酸二丁酯(DBP)对其急性毒性作用和慢性毒性作用,同时还研究了环境因素(温度、硬度、腐殖酸)对DBP24h-EC(50)的影响.结果表明DBP对大型蚤的24h-EC_(50)为10.35mg·1~(-1),温度、硬度和腐殖酸对DBP24h-EC_(50)均有一定影响.DBP对大型蚤的捕食行为产生抑制,EC_(50)在 6—7mg·1~(-1)之间.慢性毒性实验结果表明DBP对大型蚤的生长繁殖产生一定影响,低浓度DBP对大型蚤生长繁殖有一定的刺激作用,高浓度DBP对大型蚤生长繁殖存在抑制作用,BDP的最大允许安全浓度为1—2mg·1~(-1).     

Effects of Population Size, Mating System, and Evolutionary Origin on Genetic Diversity in Spiranthes sinensis and S. hongkongensis

Hong Kong once supported more than 109 species of wild orchids, of which approximately 30% were endemic. Most of the local wild orchids have now become rare or endangered. I conducted a comparative study of genetic diversity in two closely related terrestrial orchids, an allotetraploid, Spiranthes hongkongensis , and its diploid progenitor, S. sinensis , to assess the effects of the population bottleneck associated with the origin of the polyploid and to investigate the relationships between number of breeding individuals, mating system, and level of isozyme variation in their populations. Nearly complete genetic uniformity was observed both within and among populations of S. hongkongensis . In contrast, S. sinensis had high levels of genetic variation for all of the genetic parameters examined. Regression analysis of population size and several components of genetic diversity in S. sinensis revealed that, among various measures of within-population variation, the proportion of polymorphic loci ( P ) and average number of alleles per locus ( A ) or per polymorphic locus ( A _p ) were the most sensitive to population size ( R ² = 0.942, p = 0.001; R ² = 0.932, p = 0.002; and R ² = 0.923, p = 0.002 respectively). The highly negative correlation ( r = −0.999, p < 0.01) between population size and the mean frequency of private alleles in pairwise population comparisons, p (1), indicated that population size may also be used to predict the extent of population differentiation caused by random genetic drift. Conservation of genetic diversity in S. sinensis could be maximized by protecting several of both large and small populations, whereas fewer populations may be needed to achieve this goal for S. hongkongensis.     

Degradation of 4-aminophenol by hydrogen peroxide oxidation using enzyme from Serratia marcescens as catalyst

This paper reports on the degradation of 4-aminophenol using hydrogen peroxide as oxidizer and the enzyme from Serratia marcescens AB 90027 as catalyst. The effecting factors during degradation and the degrading mechanism were studied. Also, the location of the enzyme in the cell, which could catalyze the degradation of 4-aminophenol, was analyzed. The results showed that to degrade 50 mL of 4-aminophenol whose concentration was 500 mg/L, the optimal conditions were: volume of H₂O₂ = 3 mL, temperature = 40–60°C and pH = 9–10. In the degradation process, 4-aminophenol was first converted to benzoquinone and NH₃, then organic acids including maleic acid, fumaleic acid, and oxalic acid were formed, and then finally CO₂ and H₂O were generated as final products. The enzyme that could catalyze the degradation of 4-aminophenol was mainly extracellular enzyme.     

广州市城市森林的空间特征与发展研究

应用城市林业的基本理论和ＧＩＳ技术，广州市城区森林的空间分布以两山（白云山、越秀山）两河（珠江、流溪河）为核心，辅之公共绿地和道路绿化，形成多功能、多类型的网络式结构。近郊森林建设好风暴旅游林以及环绕卫星城镇和重点工业镇的生态公益林。远郊森林保障了“菜蓝子”工程，促进森林旅游及其相关产业的发展。     

多目标优化方法在城市污水厂汇水区污染源总量控制规划中的应用

在城市污水处理厂汇水区实行污染源总量控制,应该避免与城市污水处理厂重复治理.针对这个问题,提出难降解有机物控制的多目标准则指标,建立了多目标优化模型.