浅析生态园林城市的建设--以重庆市为例

随着社会、经济的快速发展，城市生态环境问题越来越突出，由此人们提出了建设生态园林城市的构想，即实现了人与自然、人与社会的和谐统一，实现了可持续发展的人类聚居地。山水园林城市与生态城市在本质上是一致的。本文以重庆市为例，从自然、经济、社会三个生态亚系统入手，分析了重庆市生态系统的现状，主要是提出目前面临的问题和矛盾，并在此基础上提出重庆市建设山水园林城市的5条途径。     

关于排污总量监测有关问题的探讨

分析了排污总量监测过程中关于实施总量监测排污口的规范化、优化设置总量监测点位、监测频次和采样方法、超标污染物判别等方面与污染源监督监测的区别以及存在的问题,并提出了相应的对策和措施。     

匹配厌氧氨氧化的SHARON工艺启动研究

氧化部分氨氮到亚硝酸氮,然后进行完全自养厌氧氨氧化反应,即称SHARON-ANAMMOX工艺,该工艺是近年开发的针对高浓度氨氮废水生物处理较为经济合理的技术之一。其过程控制的关键是第一步亚硝化(SHARON)工艺积累亚硝酸菌,并使氨氮氧化到亚硝酸氮的转化率控制在50%左右,以最合理满足厌氧氨氧化对底物的需求。在进水pH=7.6,ρ(氨氮)=750 mg/L时顺利启动了SHARON反应器,氨氮的转化率达50%左右。研究结果表明,进一步提高氨氮浓度和进水pH,反应器可以维持稳定运行。     

重庆三峡库区主要生态环境问题与对策

三峡水电站建成后，制约重庆经济可持续发展的关系是生态环境问题，包括三峡库区的水体污染，水土流失与泥沙问题，灾害性地质环境问题，建议建立三峡库区生态环境委员会，实行在市长领导下的环境保护行政领导责任制依法治库，加强生态环境意识教育，建立生态环境保护基金等。     

水中安替比林的紫外光降解研究

以波长为254 nm的紫外杀菌灯为光源,研究了水溶液中消炎镇痛药物安替比林（PZ）的光降解行为;考察了初始pH值及水中其他物质对PZ光降解的影响,探讨了PZ光解机制,并分析其降解产物及光解途径。结果表明,安替比林的光降解遵循拟一级反应动力学规律,pH值变化对光解速率基本没有影响。安替比林直接光降解占主导作用,活性氧类物种（ROS）对安替比林间接光解基本没有贡献。腐殖酸对安替比林光降解有抑制作用,而NO^-₃,HCO^-₃,Cl^-对安替比林光降解没有明显作用。GC-MS分析表明安替比林在紫外辐射下生成甲酰胺,乙酰胺,2-羟基吲哚-3-酮,2,4（1氢,3甲基）-喹唑啉二酮,1-甲基-2-羟基苯并咪唑,2-羟基苯并恶唑等一系列具有安替比林母体苯环结构的化合物,表明安替比林侧链上N—N键断裂导致其最终降解。     

甲烷气体标准样品的研制

对称量制备甲烷气体标准样品的制备方法进行了详细研究 ,对可能引起甲烷量值不确定度的各种误差来源进行了分析。文中提出的甲烷气体标准样品制备方法具有很好的重现性 ,所制备的甲烷气体标准样品具有良好的压力稳定性并已能在三种气瓶中稳定保存 1 8个月 ,其量值准确、可比 ,并已在全国环境监测网试用。     

论在社会主义市场经济条件下地震台站建设的几个问题

地震台站是地震科学发展和顺利完成我国防震减灾任务的基础单元。随着我国改革开放的不断深化,我省的地震台站面临着许多新的问题。文章对此进行了剖析,提出可从加强政治思想工作、转变思想观念、拓宽工作领域等方面解决这些问题。同时提出应注意认真选拔地震台长并加强对他们的培养,帮助台站建立一套灵活的用人制度等合理化建议。     

基于遗传-神经网络的电网流域面雨量预报方法研究

以重点水力发电厂和大中型水库为主要考量,并兼顾地形地貌和中小河流的分布特征,将广西划分为23个电网流域,研究了基于非线性的神经网络电网流域面雨量预报方法。以5-6月龙滩近库区、龙江流域等6个电网流域为例,利用遗传算法优化BP神经网络的连接权和网络结构,建立了各电网流域的遗传-神经网络电网流域面雨量预报模型。对独立样本的预报结果表明,基于遗传-神经网络的电网流域面雨量预报模型的预报能力要优于传统的逐步回归预报模型,也明显优于日本、德国数值模式预报产品所换算成的电网流域面雨量预报,并与气象部门同期制作的综合面雨量预报产品能力相当,因而,遗传-神经网络面雨量集合预报模型有较好的业务应用前景。     

Genotoxicity of two novel pesticides for the earthworm, Eisenia fetida

In this paper, several studies were conducted to evaluate the genotoxicity of two pesticides, Imidacloprid and RH-5849, for earthworm (Eisenia fetida). Earthworms were exposed in different exposure systems to evaluate their acute toxicity and the genotoxicity of the two pesticides was evaluated by using the method of sperm deformity assessment, micronucleus test of root tip cells in Vicia faba, a mouse bone-marrow micronucleus test, and comet assay. LC(50) (interpolated concentration at which 50% mortality of test population occurs) for earthworms varied in different exposure systems. The results indicated that Imidacloprid was consistently more toxic than RH-5849 in all exposure systems. In this study, sperm deformity test was used to detect the potential adverse influences of pesticides on the reproduction of earthworms. The results demonstrated that significant induction of sperm deformity (p<0.01) and a dose-effect relationship displayed at Imidacloprid concentrations higher than 0.5 mg/kg dry soil. However, the sperm deformity frequency of groups exposed to RH-5849 did not show significant difference (p>0.05) from the control until the dose reached 100 mg/kg dry soil. The results of the V. faba micronucleus tests showed that micronuclei frequency of the exposed group did not show significant difference (p>0.05) from the control until the concentration of Imidacloprid and RH-5849 reached 100 mg/ml. The results of the mouse bone-marrow micronuclei test also indicate that two pesticides did not show significant effects (p>0.05) on the micronuclei frequency in mice bone-marrow cells until the dose reached 100 mg/kg for Imidacloprid and 300 mg/kg for RH-5849 (2/3 LD(50)). Although no genotoxicity was detected by using the micronucleus tests, the results of the comet assay showed that the two pesticides induce significant DNA damage (p<0.01) in earthworms and dose-effect relationships were displayed. The 'earthworm comet assay' is a rapid and sensitive way to screen chemicals or terrestrial environments for their DNA-damaging properties.     

Cadmium contamination in orchard soils and fruit trees and its potential health risk in Guangzhou, China

This study examines cadmium (Cd) contamination in orchard soils and fruit trees in Guangzhou, China, and assesses its potential health risk. Soils and tissues samples of three species of fruit trees were collected from three orchards. The average soil Cd concentration was 1.27, 1.84 and 0.68 mg/kg in orchards I, II, and III, respectively. The carambola (Averrhoa carambola) accumulated exceptionally high concentrations of Cd (7.57, 10.84, 9.01 and 2.15 mg/kg dw in root, twig, leaf and fruit, respectively), being 6.0-24 times and 4.0-10 times the corresponding tissue Cd in the longan (Dimocarpus longan) and wampee (Clausena lansium), respectively. Furthermore, all Cd concentrations (0.04-0.25 mg Cd/kg fw) of the fruits exceeded the tolerance limit of cadmium in foods of PR China (0.03 mg/kg fw). Our results indicate that the carambola tree has high Cd accumulation capacity and might be a Cd accumulator; and its fruit, among the three species of fruits studied, also poses the highest potential health risk to local residents.