Factors affecting the sex ratio in the honeybee mite <Emphasis Type="Italic">Varroa jacobsoni</Emphasis>

Study of the seasonal variation of the sex ratio in the honeybee mite Varroa jacobsoni demonstrated that sex determination was affected by temperature, order of reproductive cycles, and population densities in the host’s brood cell and the honeybee nest. The mechanism of reproduction ensuring adaptation of the mite to parasitism and reproduction on honeybees are discussed.     

主成分分析法在水质评价中的应用及分析

针对主成分分析能够从众多因子中筛选出主要成分,对数据结构进行简化,为后续工作筛选主要因子提供依据等优点,分别介绍了主成分分析法的原理和步骤,并将其应用于水质评价中。以淮河安徽段干流的十一个断面为例,选取了八个因子进行分析研究。结果表明：对涉及因子较多,且因子间相关性相对较大的水质进行评价时主成分分析法是一种有效的方法。     

Contributing institutional factors of rural environmental pollution in the process of modernization in China —In the perspective of the efficiency of environmental management system

With the development of rural pollution, its characteristic and institutional factor should be studied for pollution control through economics and sociology. Based on the data gathered from investigations by several government sectors, rural environmental pollution can be divided into two types by its sources: internal source type and external source type. The internal source type is the main component of rural pollution at present, which can be further divided into three types. Research shows that the contributing institutional factors of rural pollution issues and the effectiveness of environmental management system over rural pollution can be summarized as distinctiveness. In essence, the rural pollution issue results from the dualism of rural and urban areas’ inadaptability to rural modernization. In detail, the contributing factors can be summed up on three institutional levels. There are obvious loopholes in rural environmental management system which, in the meantime, is incapable and inadaptable to rural pollution control. There exist similar questions in the related public service system, which are intensified by inappropriate reform which brought about incompatible incentive in the recent years. However, in the eleventh five-year plan period, there are advantageous trends in the three institutional levels. Main data sources in this paper: ➀ the surveys on TVEs (township and village enterprises) conducted by Township Enterprise Bureau of Ministry of Agriculture of China in 1997 and 2002; ➁ the partial survey on rural environmental conditions by EPA (environmental protection administration) of Zhejiang Province in 2002; ➂ the survey on the pollution of IPLFs (livestock and poultry farms) in 23 provinces, municipalities, and directly administered cities by the State Environmental Protection Administration of China in 2002; ➃ the research report on Mechanism of Investment and Financing for Environmental Protection by China Council for International Environment and Development Cooperation in 2003; ➄ the third investigation on national hygiene service in 2003; ➅ the regular monitoring of safe quality of agricultural products by the Ministry of Agriculture of China in 2005; ➆ the investigation arranged by the Ministry of Health which finished in 2007 and showed the total situation of rural environmental health and drinking water security of the whole country.     

电缆燃烧产烟影响因素的试验研究

利用锥形量热仪和烟密度仪通过试验分别测量了ZR-VV 4×6、ZR-YJV 4×6、YJV 4×6三种型号的电缆在一定辐射强度下烟气的释放速率、质量损失速率以及有效燃烧热等火灾参数,分析、比较了它们之间的关系,并通过改变电缆的附着基材、燃烧时环境的氧浓度得到这些因素对电缆的产烟有不同程度的影响,该研究为实际工程中电缆的敷设以及电缆火灾的扑救提供了依据.     

废弃重组质粒DNA热处理效率的环境影响因素

为了解环境因素对质粒DNA热处理效率的影响以及热处理过程的有效性和安全性,以pET-28b质粒为材料,采用定量PCR技术结合质粒转化等方法分析了pH、NaCl、牛血清白蛋白(BSA)及EDTA浓度等因素对质粒DNA热处理的影响.结果表明,NaCl、BSA及EDTA的存在对热处理过程中的质粒DNA具有保护作用,且保护作用依次增强.在纯水中热处理30min后的质粒DNA可扩增的片段数仅是在0.1%的EDTA中热处理30min后质粒DNA可扩增片段数目的1.7%.由于生物实验室废水中通常含有上述有机或无机物质,因此,实际热处理过程中质粒DNA的降解半衰期可能远长于先前报道的2.7～4min,残留的转化活性也可能更高,这必须引起我们高度关注.但是,研究结果也表明,酸性条件下的热处理能加速质粒DNA的失活和降解,因此建议热处理过程可在弱酸性条件下完成,以强化其处理效果.     

电催化氧化法处理苯胺废水试验研究

根据正交实验结果分析电压、pH、电解质和电解时间对苯胺降解率的影响,得出电压的影响最大,pH的影响次之,再次是电解时间,而电解质的投加量对苯胺降解率的影响比较微弱。并为工业应用确定了反应条件：电解电压为6V,pH=8,电解时间为60min,Na2SO4浓度为9g/L。     

规划环境影响评价有效性探讨

以规划环境影响评价有效性为研究对象,从规划体系复杂性、评价重点识别、理论与技术支持不够等方面分析了影响规划环境影响评价的内在制约因素;从经济、法律、行政管理、文化等方面分析了影响规划环境影响评价的外在制约因素;并从对象、过程、内容、监督和资源支持5个方面探讨了在规划环境影响评价实施全过程中提高有效性的方式和方法。     

典型喀斯特坡地137Cs的分布与相关影响因子研究

通过野外考察和大量的137Cs取样分析,对喀斯特坡地土壤137Cs分布及相关影响因子进行了初步研究.结果表明,喀斯特区域137Cs剖面分布特征与非喀斯特区域相似,林地土壤剖面137Cs呈现指数分布模式,耕地剖面的137Cs呈均匀分布模式;喀斯特区域落水洞洞口45 cm以上土层中的137Cs比活度变幅为1.7~3.3 Bq/kg,137Cs分布较深,表明洞口现存土壤多由侵蚀物质堆积形成;2个石缝中的土壤样品137Cs比活度分别为16.8 Bq/kg和37.6 Bq/kg,远远高于临近土体,表明裸岩是影响喀斯特区域137Cs地表空间运移的一个重要因素;随坡面海拔升高,137Cs的面积活度表现出波动振荡趋势,空间异质性明显,林地和农耕地坡面137Cs面积活度变幅分别为299.4~1 592.6 Bq/m2和115.8~1 478.6 Bq/m2;林地坡面137Cs面积活度与坡度和海拔高度呈极显著正相关,农耕地坡面137Cs面积活度和坡度呈不明显的负相关,与海拔高度呈显著负相关.地形地貌和人为干扰强度是影响坡面137Cs空间分布规律的主要因素.     

盐城湿地沉积物环境特征及其影响因素研究

盐城沿海湿地是国家级自然保护区,正面临环境的污染和生态破坏的威胁。为了有效地保护和恢复其受损的生态功能,文章通过实地采样分析的方法研究了盐城湿地底泥氮、磷及有机物含量与分布规律及其影响因素。研究表明盐城湿地受潮流与河流水动力条件的长期综合作用,该区从陆地向海洋方向,沉积物粒度呈现由细变粗的总体变化规律。潮间带沉积物中氮、磷及有机碳在空间上也呈现出从光滩向高潮位区逐渐增加的趋势。沉积物中营养物释放与微小颗粒物的再悬浮成为潮间带水体富营养化的一个重要因素。     

农业流域营养盐流失的关键因素及其防治途径

全面分析农业流域氮、磷等污染物质流失的关键过程,识别主要影响因素,研究探讨农业面源污染影响因素的作用方式和治理途径,对于农业面源污染控制具有重要意义。以国内外大量相关研究成果为基础,全面分析了农业面源污染的主要产生机理,以及影响农业面源污染时空分布的主要因素及相互作用关系,详细探讨了土壤性质、植被类型、土地利用格局、径流驱动因素、农业生产模式等关键因素对农业面源污染流失特征的影响作用,并从农田管理、景观结构调整、农业生产格局优化等方面有针对性的提出了适合中国农业流域特点的面源污染防控措施。