乌鲁木齐市生态环境现状调查

乌鲁木齐市深居亚欧大陆腹地,远离海洋,气候干旱,降水稀少,植被稀疏,风沙危害严重,生态极期脆弱,属典型的温带半干旱绿洲生态环境。对乌鲁木齐市“八五”及“九五”期间的生态环境状况进行了多方面的调查分析。并就存在的问题谈了作者的观点,以供同行参考。     

EFFECTS OF INITIAL ABSTRACTION AND URBANIZATION ON ESTIMATED RUNOFF USING CN TECHNOLOGY1

ABSTRACT: Few studies have been conducted to explore the effects of initial abstraction on estimated direct runoff despite the widespread use of the curve number (CN) method in many hydrologic models to estimate direct runoff. In this study, use of a 5 percent ratio of initial abstraction (I_a) to storage (S) to estimate daily direct runoff with modified CN values for a 5 percent I_a/S value was investigated using the Long‐Term Hydrologic Impact Assessment (L‐THIA) geographic information system (GIS). In addition, the effects on estimated runoff of altering the hydrologic soil group due to urbanization were investigated. The L‐THIA model was applied to the Indiana Little Eagle Creek watershed with 5 percent and 20 percent I_a/S values, considering hydrologic soil group alteration due to urbanization. The results indicate that uses of a 5 percent l_a/S and modified CN values and Hydrologic Soil Group D for urbanized areas in model runs can improve long term direct runoff prediction.     

金沙江水电资源梯级开发及其经济发展研究

金沙江流域是我国13大水电基地中水能资源蕴涵量最大的地区，但开发率相对较低。在介绍金沙江流域丰富的水电资源及其开发现状的基础上，分析了加快金沙江水电开发的可能条件和重要意义；针对开发中存在的主要问题，根据市场经济原则和具体情况提出了对策和建议。     

有机酸性腐蚀品生产危险性分析

目前我国化工生产中涉及大量有机酸性腐蚀品,通过对某市化工行业调查及分析,发现有机酸性腐蚀品生产普遍,而且生产原料易燃易爆,生产过程存在火灾爆炸危险,结合具体生产工艺,采用预先危险性分析法和作业条件的危险性评价法分析生产过程危险性,从而揭示并概括有机酸性腐蚀品生产危险性.为更好地促进我国安全生产,在此基础上探讨了一些针对性的安全措施.     

Modeled Summer Background Concentration of Nutrients and Suspended Sediment in the Mid‐Continent (USA) Great Rivers1

Angradi, Ted R., David W. Bolgrien, Matt A. Starry, and Brian H. Hill, 2012. Modeled Summer Background Concentration of Nutrients and Suspended Sediment in the Mid‐Continent (USA) Great Rivers. Journal of the American Water Resources Association (JAWRA) 48(5): 1054‐1070. DOI: 10.1111/j.1752‐1688.2012.00669.x Abstract: We used regression models to predict summer background concentration of total nitrogen (N), total phosphorus (P), and total suspended solids (TSS), in the mid‐continent great rivers: the Upper Mississippi, the Lower Missouri, and the Ohio. From multiple linear regressions of water quality indicators with land use and other stressor variables, we determined the concentration of the indicators when the predictor variables were all set to zero — the y‐intercept. Except for total P on the Upper Mississippi River, we could predict background concentration using regression models. Predicted background concentration of total N was about the same on the Upper Mississippi and Lower Missouri Rivers (430 μg l^?1), which was lower than percentile‐based values, but was similar to concentrations derived from the response of sestonic chlorophyll a to great river total N concentration. Background concentration of total P on the Lower Missouri (65 μg l^?1) was also lower than published and percentile‐based concentrations. Background TSS concentration was higher on the Lower Missouri (40 mg l^?1) than the other rivers. Background TSS concentration on the Upper Mississippi (16 mg l^?1) was below a threshold (30 mg l^?1) designed to protect aquatic vegetation. Our model‐predicted concentrations for the great rivers are an attempt to estimate background concentrations for water quality indicators independent from thresholds based on percentiles or derived from stressor‐response relationships.     

毛木耳产漆酶发酵条件的研究

以毛木耳为产酶菌，以CMC为唯一碳源，探讨了不同培养条件对毛木耳产漆酶的影响。结果表明，在最适温度为27℃、pH值为6．0、接种量为10％、装液量为90mL／250mL、摇床转速为180rpm、培养天数为6d时，产酶活力最大。以各个因子的最佳梯度做优化培养，发酵液中的漆酶活力高达70．76IU／mL。     

影响原油生物降解因素的实验研究

以原油为唯一碳源,从长期被石油污染土壤中筛选出6株原油降解菌SY1~SY6,通过单因素实验研究初始pH、温度、充氧量(摇床转数)、盐浓度、氮源和磷源等环境因素和营养条件对各菌株生物降解原油的影响。实验结果表明:6株原油降解菌在初始pH7~9,温度30℃,摇床转速180 r/min时生长良好,且能有效地降解石油类污染物,其平均降解率为50%以上。6菌株在盐浓度在1%时生长良好,SY3菌和SY4菌能在盐浓度10%以上生长,具有一定的耐盐能力。同时,6菌株以氯化铵(NH4Cl)为氮源,磷酸氢二钾(K2HPO4)和磷酸二氢钾(KH2PO4)的混合物(2∶1)为磷源时生长良好,因此可作为各菌生长的最适氮源和磷源。研究结果可以为含油废水的处理提供微生物基础。     

A strategy for aromatic hydrocarbon bioremediation under anaerobic conditions and the impacts of ethanol: a microcosm study

Increased use of ethanol-blended gasoline (gasohol) and its potential release into the subsurface have spurred interest in studying the biodegradation of and interactions between ethanol and gasoline components such as benzene, toluene, ethylbenzene and xylene isomers (BTEX) in groundwater plumes. The preferred substrate status and the high biological oxygen demand (BOD) posed by ethanol and its biodegradation products suggests that anaerobic electron acceptors (EAs) will be required to support in situ bioremediation of BTEX. To develop a strategy for aromatic hydrocarbon bioremediation and to understand the impacts of ethanol on BTEX biodegradation under strictly anaerobic conditions, a microcosm experiment was conducted using pristine aquifer sand and groundwater obtained from Canadian Forces Base Borden, Canada. The initial electron accepter pool included nitrate, sulfate and/or ferric iron. The microcosms typically contained 400 g of sediment, 600 approximately 800 ml of groundwater, and with differing EAs added, and were run under anaerobic conditions. Ethanol was added to some at concentrations of 500 and 5000 mg/L. Trends for biodegradation of aromatic hydrocarbons for the Borden aquifer material were first developed in the absence of ethanol, The results showed that indigenous microorganisms could degrade all aromatic hydrocarbons (BTEX and trimethylbenzene isomers-TMB) under nitrate- and ferric iron-combined conditions, but not under sulfate-reducing conditions. Toluene, ethylbenzene and m/p-xylene were biodegraded under denitrifying conditions. However, the persistence of benzene indicated that enhancing denitrification alone was insufficient. Both benzene and o-xylene biodegraded significantly under iron-reducing conditions, but only after denitrification had removed other aromatics. For the trimethylbenzene isomers, 1,3,5-TMB biodegradation was found under denitrifying and then iron-reducing conditions. Biodegradation of 1,2,3-TMB or 1,2,4-TMB was slower under iron-reducing conditions. This study suggests that addition of excess ferric iron combined with limited nitrate has promise for in situ bioremediation of BTEX and TMB in the Borden aquifer and possibly for other sites contaminated by hydrocarbons. This study is the first to report 1,2,3-TMB biodegradation under strictly anaerobic condition. With the addition of 500 mg/L ethanol but without EA addition, ethanol and its main intermediate, acetate, were quickly biodegraded within 41 d with methane as a major product. Ethanol initially present at 5000 mg/L without EA addition declined slowly with the persistence of unidentified volatile fatty acids, likely propionate and butyrate, but less methane. In contrast, all ethanol disappeared with repeated additions of either nitrate or ferric iron, but acetate and unidentified intermediates persisted under iron-enhanced conditions. With the addition of 500 mg/L ethanol and nitrate, only minor toluene biodegradation was observed under denitrifying conditions and only after ethanol and acetate were utilized. The higher ethanol concentration (5000 mg/L) essentially shut down BTEX biodegradation likely due to high EA demand provided by ethanol and its intermediates. The negative findings for anaerobic BTEX biodegradation in the presence of ethanol and/or its biodegradation products are in contrast to recent research reported by Da Silva et al. [Da Silva, M.L.B., Ruiz-Aguilar, G.M.L., Alvarez, P.J.J., 2005. Enhanced anaerobic biodegradation of BTEX-ethanol mixtures in aquifer columns amended with sulfate, chelated ferric iron or nitrate. Biodegradation. 16, 105-114]. Our results suggest that the apparent conservation of high residual labile carbon as biodegradation products such as acetate makes natural attenuation of aromatics less effective, and makes subsequent addition of EAs to promote in situ BTEX biodegradation problematic.     

高寒条件下振弦式传感器在线测量尾矿坝浸润线的误差分析及对策

为减少和消除高寒条件下振弦式传感器在线测量浸润线的误差,通过理论分析和现场试验,对造成误差的因素及其影响情况进行了深入研究。结果表明,振弦式传感器产生测量误差的主要来源为设备安装深度的测量误差与尾矿水密度及重力加速度的取值误差,并提出了减少或消除误差的方法和工程技术措施,为高寒地区的浸润线在线精确测量提供了重要指导意义。     

基于二值逻辑的复合绝缘子状态判别策略研究

复合绝缘子是架空输电线路上广泛使用的设备,它的老化会给电力系统的正常运行带来威胁。电力相关工作人员需要一种能够对复合绝缘子的运行状态进行判别的方法,帮助他们确定复合绝缘子是否满足运行要求,而对复合绝缘子的定性表征就成为一种优选的表征策略。将运行后的复合绝缘子分成"满足运行要求"和"不满足运行要求",使用二值逻辑回归模型,选取合适的特征量,建立了复合绝缘子状态表征体系。