宝鸡渭北冰雹地理分布及减灾对策

采用宝鸡渭北地区40年（1961～2000年）的冰雹资料,结合实际调查,分析了渭北冰雹的地理分布及其移动路径.结果表明：宝鸡渭北地区降雹的年、月、日变化比较显著,降雹强度与地理环境密切,北部山区降雹多于渭河川原,主要分布于泾河与千河之间的分水岭南侧及喇叭口形的谷地中,冰雹移动路径与河谷走向基本一致.根据当地情况,提出了加强预测预报、人工消雹,以及建造林带和改良土壤,从而改变下垫面条件的减轻冰雹灾害的对策.     

水污染问题的经济学分析及其对策探讨

针对我国水资源污染的现状,从经济学角度对水污染的原因进行了分析,指出在公共资源产权没有明确界定的情况下,公共资源总是被过度利用,水资源产权制度缺损导致的外部性是水污染问题产生的根本原因;提出通过状态转移、实行产权管理、建立完善的市场调节机制和法律体系,是解决我国水污染问题的根本出路.     

垃圾填埋处理中微量金属元素迁移和转变特性分析

城市生活垃圾中含有多种微量金属元素，并且在填埋处理过程中会产生重金属的二次污染，是城市垃圾填埋处理中最难解决的问题。本文对垃圾中微量金属的来源、微量金属在填埋过程中的迁移和转变特性等方面进行了研究。研究认为，微量金属在填埋处理过程中除受本身特性的影响，还与垃圾的产地和组成有关。     

A/O法处理城市污水中有机物迁移转化的研究(Ⅱ)

本文通过实验方法对采用A／O工艺处理城市污水过程中有机物的迁移和转化进行了研究。所采用的方法是将原水、处理后的出水及污泥用甲苯萃取，萃取相经过真空浓缩后，采用色谱-质谱法(GC／MS)对样品中的有机化合物进行了测定。结果表明，在A／O工艺处理城市污水过程中，活性污泥对有机物的吸附作用是主要的，降解作用是次要的。     

A MIXING MODEL FOR A SEPARATED MECHANICAL AERATION SYSTEM1

ABSTRACT: An input-output method, using a network of ideal continuous stirred-tank and plug-flow tublar reactors, is adopted to analyze residence time distribution data for a separated mechanical aeration system. The usefulness of this modeling concept is enhanced by its simplicity, especially in the presence of a first-order reaction. This facilitates use of the model format for wastewater quality prediction. Moreover, first-order rate constants can also be estimated from the model, if conversions due to the reaction rate are available.     

USER-ORIENTED RESEARCH DESIGNS1

ABSTRACT: A user-oriented research plan is presented herein. Its principal components are: (1) a mechanism for identifying social goals and translating them into research objectives; (2) procedures for setting priorities; (3) a program planning technique for designing projects to impact on important research objectives; (4) a mechanism for coordinating research activities of important research producers; (5) a structure for encouraging and establishing interdisciplinary team efforts when they are required; (6) a well-coordinated technology transfer plan; and (7) an effective method for promoting and sustaining user-researcher cooperation. Both basic and applied research designs are examined and criteria presented. The implementation of research plans is also discussed and various factors which play a role in implementation are outlined including: coordination, goal interpretation and priority setting, project Planning, Project review, interdisciplinary considerations and the user-researcher interface.     

STATUS REPORT ON HEAT STORAGE WELLS1

ABSTRACT. The Heat Storage Well concept evolved at TEMPO in 1972. Technical, economic, institutional, and legal aspects of implementing the concept are being studied. Heat Storage Wells offer the possibility of conserving a substantial part of the heat energy now wasted in generating electricity and of reducing thermal pollution caused by the waste heat. Large thermal electric power plants would produce heat at useful temperatures such as 300–400°F. Combined electric- and heat-generating systems will require low-cost, low-loss storage of large amounts of hot water for periods of 90 to 180 days to serve both electric loads and seasonally-varying heat loads. Compared to conventional electricity-only systems, combined electricity-heat systems can save more than 20 percent in energy, reduce the cost of both electricity and heat, and eliminate the need for cooling water or towers. Possibilities for changes in legal and institutional practices are suggested, such as making resource-allocation decisions on the basis of energy units rather than dollars.     

Atmospheric mercury emissions from polluted gold mining areas (Venezuela)

Soil, waste rock and mud from mercury-gold amalgamation mining areas of El Callao (Venezuela) are highly enriched in Hg (0.5–500 μg g⁻¹) relative to natural background concentrations (<0.1 μg g⁻¹). Mercury fluxes to the atmosphere from twelve polluted sites of this area were measured in situ (6 a.m. to 8 p.m.) using a Plexiglas flux chamber connected to a portable mercury analyzer (model RA-915+; Lumex, St. Petersburg, Russia). Mercury fluxes ranged between 0.65 and 420.1 μg m⁻² h⁻¹, and the average flux range during the diurnal hours␣was 9.1–239.2 μg m⁻² h⁻¹. These flux values are five orders of magnitude higher than both reported world background Hg fluxes (1–69 ng m⁻² h⁻¹) and the regional values, which are in the range 2–10 ng m⁻² h⁻¹. The flux results obtained in this study are, however, similar to those measured at Hg polluted sites such as chloro-alkali plants or polymetallic ore mining districts (>100,000 ng m⁻² h⁻¹). The results from this study also show that Hg emissions from the soil are influenced by solar radiation, soil temperature and soil Hg concentration. Our data suggest that solar radiation may be the dominant factor affecting Hg° emission since the major species of mercury in polluted soil is Hg° (85–97% of total Hg). The simple release of Hg° vapor is probably the dominant process occurring with incident light in the field. The apparent activation energy for mercury emission indicates that the volatilization of mercury mainly occurred as a result of the vaporization of elemental mercury in soil. The degree of Hg emission differed significantly among the soil sites studied, which may be due to variations in soil texture, organic matter content and soil compaction.     

若尔盖高原泥炭沼泽湿地CO2呼吸通量特征

若尔盖高原沼泽湿地是我国最大的高原泥炭沼泽湿地。采用静止箱/气相色谱法,2004年5月至10月对若尔盖高原泥炭沼泽湿地CO2呼吸通量进行了观测。沼泽湿地CO2呼吸通量平均值为200.40mg·m-2·h-1,最大值为402.37mg·m-2·h-1,最小值为61.09mg·m-2·h-1。沼泽湿地周边的沼泽化草甸CO2呼吸通量平均值为425.50mg·m-2·h-1,最大值为891.74mg·m-2·h-1,最小值为124.23mg·m-2·h-1。二者均在7、8月出现排放峰值。沼泽湿地CO2呼吸通量日变化为单峰型,高峰出现在13时和15时。沼泽湿地CO2呼吸与温度具有相关性,其中与5cm深的土壤温度相关性最好。若尔盖高原沼泽湿地CO2呼吸通量的平均值仅为三江平原常年积水沼泽湿地的约36%,这可能是若尔盖高原沼泽湿地有泥炭积累,而三江平原沼泽湿地无泥炭积累或仅有少量积累的重要原因之一。     

二氧化氯与苯酚的单电子转移反应机理

用量子化学从头算方法 ,研究了二氧化氯 (ClO2 )的电子结构以及与苯酚反应的单电子转移机理 ,在HF/4 31G 水平上用梯度解析技术全参数优化上述反应的反应物、中间体 (过渡态 )和产物构型 ,并计算了相应构型的能量 .通过对酚氧自由基的振动频率分析 ,验证了它为平衡构型 .计算结果表明 :ClO2 在水处理条件下与苯酚的反应是按单电子转移机理进行的 ,该反应为放热反应 ,放出的能量约为 2 0 0kJ·mol- 1 .