青海湖地区草地蝗虫发生的气候背景

气候条件对环青海湖地区草地蝗虫的发生程度有重要影响。上一年的下半年气温偏低和当年高温干旱 ,是蝗虫发生的有利气候条件 ;上一年的 8月份、当年 5月下旬到 7月上旬以及当年 8月份的气候条件与蝗虫发生程度密切相关。     

浅谈水质档案的作用

本文着重对水质档案在掌握最新信息、评价水质状况和了解水质变化动态等方面所起的作用,进行了详细讨论,并明确了水质档案在水质管理方面的重要地位。     

城市垃圾厌氧干发酵非甲烷菌群分布变化研究

为研究非甲烷菌的菌群分布随时间、空间变化对厌氧干发酵的影响,以城市垃圾为原料进行分析,同时测定pH值。结果表明,启动阶段好氧及兼性厌氧细菌属优势菌,其中产酸菌增殖速率高于氨化细菌,7 d达最大值2.95×109MPN/mL,是启动阶段降解有机质的主要菌群,而氨化菌在15 d达最大值1.93×108MPN/mL。随后厌氧细菌快速增殖并保持稳定,且仍是产酸菌占优势,15 d达最大值1.55×1010MPN/mL。厌氧纤维素降解菌增殖较慢,发酵30 d不足105MPN/mL,说明原料中纤维素降解在厌氧发酵后期。空间方面,好氧及兼性厌氧产酸菌在顶部中心最活跃,最大值是底部中心的1.4倍;厌氧产酸菌集中在底部,最大值是顶部的1.2倍。好氧氨化菌在中部中心增殖最多,厌氧氨化菌在中部边缘达最大值1.95×108MPN/mL。纤维素降解菌在底部开始增殖。研究为提高干发酵反应效率和合理设计干发酵反应器提供有效参考数据。     

Sand-dust Storm, Population and Environment in Northwest China

Sand-dust storms are the result of the integrated influences of climate, geography, society and human factors. A theoretical framework is built to explain the coherence of population growth, agriculture change and environmental degradation. On the basis of the analysis of the causes of the sand-dust storm in terms of human factors, a discussion will be given to show that these factors are internally consistent with the theoretical framework. After that, it will look at China's Agenda 21 and try to find relevant measures to reduce such large sand-dust storms happening in Northwest China and eventually make this area develop sustainably.     

拉延成形中拉延筋的摩擦分析

此文建立了一种用拉延筋单元模拟试验器测试拉延筋摩擦系数的方法,同时对成形中的摩擦润滑进行了试验研究和分析。     

周期循环静止沉淀工艺实验研究与实践

为了提高给水处理中常规沉淀池的沉淀效率，采用多个沉淀池代替常规的单一沉淀池进行沉降实验，多池依次进水、依次静止沉淀，然后出水，周期循环，并在实验的基础上提出了“周期循环静止沉淀”这种给水处理新工艺。实验结果和实践表明，周期循环静止沉淀工艺与常规连续进、出水的单一沉淀池工艺相比，其沉淀效率明显提高，其出水水质显著改善。     

Chemical speciation and anthropogenic sources of ambient volatile organic compounds(VOCs)during summer in Beijing,2004

Volatile organic compounds (VOCs) were measured at six sites in Beijing in August, 2004. Up to 148 VOC species, including C₃ to C₁₂ alkanes, C₃ to C₁₁ alkenes, C₆ to C₁₂ aromatics, and halogenated hydrocarbons, were quantified. Although the concentrations differed at the sites, the chemical compositions were similar, except for the Tongzhou site where aromatics were significantly high in the air. Based on the source profiles measured from previous studies, the source apportionment of ambient VOCs was preformed by deploying the chemical mass balance (CMB) model. The results show that urban VOCs are predominant from mobile source emissions, which contribute more than 50% of the VOCs (in mass concentrations) to ambient air at most sites. Other important sources are gasoline evaporation, painting, and solvents. The exception is at the Tongzhou site where vehicle exhaust, painting, and solvents have about equal contribution, around 35% of the ambient VOC concentration. As the receptor model is not valid for deriving the sources of reactive species, such as isoprene and 1,3-butadiene, other methodologies need to be further explored.     

垃圾卫生填埋场卫生防护距离标准研究

根据我国大气环境质量标准，参照美国，日本等国对居住区的污染物容许浓度，提出了佛山市南海狮中垃圾卫生填埋卫生防护距离标准的建议值。     

Photocatalytic reduction of Cr(VI) over cinder-based nanoneedle in presence of tartaric acid: Synergistic performance and mechanism

Cr(VI) is a common heavy metal ion, which will seriously harm human body and environment. Therefore, the removal of Cr(VI) has become an attractive topic. In this work, cinder was used as a raw material to synthesize a nanoneedle material: γ-([email protected]) (γ[email protected]). The physicochemical properties of γ[email protected] were thoroughly characterized, and its effectiveness as a catalyst for photocatalytic reduction of Cr(VI) was evaluated. The results showed that Cr(VI) could be efficiently reduced by γ[email protected] in the presence of tartaric acid (TA) under visible light. The variable factors on the reaction were investigated in detail, and the results showed that under optimal conditions (γ[email protected] 0.4 g/L, TA 0.6 g/L, pH 2), Cr(VI) was completely reduced within 7 min. Besides, scavenger experiments and EPR proved that O₂^{? —} and CO₂^{? —} played a significant role in the photocatalytic reduction of Cr(VI). TA acts as a sacrificial agent to trap the holes and generate strong reducing free radicals: CO₂^{? —}. Dissolving O₂ could react with electrons to generate O₂^{? —}. This work discussed the performance and mechanism of photocatalytic reduction of Cr(VI) in detail, which provided a new idea for the resource utilization of solid waste and the treatment of heavy metal sewage.     

刘振河打造核工业发展的安全屏障

我的理想就是推动核工业可持续发展，让人类与自然能够和谐共存。希望在中核集团、政府各部门及社会各界的大力支持下，迅速理顺处置场的产权关系与管理机制，在三废处理领域实施专业公司代建制，在强化自身建设能力基础上，通过实施专业公司专业化运作的机制，尽快在重点三废处理项目。重大核设施退役与环境治理项目上取得突破，用5～10年时间，使清原公司成为技术与管理均为一流的、在国际上有较高知名度的核环保专业公司。[编者按]