除草剂对非靶标生物及人体的生殖毒性与遗传毒性研究进展

除草剂的应用已逐渐成为农业生产中不可或缺的一环.除草剂潜在的毒性作用对生态系统及其中生存的动物和人类存在着威胁.因此,研究除草剂的生殖和遗传毒性并选用安全的品类对于生态系统的保护是十分重要的.本文综述了多种除草剂对几种非靶标生物的生殖毒性和遗传毒性,为新型除草剂的生殖和遗传毒性评价及实验动物的选择提供参考,并为除草剂的生态毒理研究提供思路.     

分层型水库藻类季相演替的细菌种群驱动机制

浮游藻类和水体中的细菌是水生食物网的组成部分,在淡水生态系统的结构和功能中发挥着关键作用.然而,对于水库当中藻类和细菌群落如何互作及其对变化的环境条件的响应研究却较少.本文以李家河水库为研究对象,采用16S rDNA高通量测序技术和共生网络分析方法,分析了藻类种群时空演替与细菌群落的生态互作关系.结果表明,在藻类群落结构中,硅藻和绿藻也为全年优势门类,且在8月,蓝藻取代硅藻成为第二大优势门类,平均相对丰度为30.13%.DNA测序分析表明,变形菌门、放线菌门和拟杆菌门为全年优势细菌,其中变形菌门在7月达到全年最大相对丰度71.68%.酸杆菌门和异常球菌-栖热菌门作为稀有类群,其相对丰度最大分别为10.20%和5.56%.共生网络分析表明,藻类与细菌之间的关系以正相关居多,表明二者之间的互作关系可能以互利共生为主.Methylotenera作为关键节点,与小球藻呈显著正相关.柵藻作为藻类群落中的关键节点,与甲基杆菌属、Solitalea和红育菌属等多种细菌显著负相关.RDA分析表明,藻类和细菌群落的演替受到水温、pH和电导率的显著调控,环境因子对藻类和细菌群落变异解释分别为93.1%和90%.本研究结果将为深水型水源水库生态系统中藻菌互作关系的微生态驱动机制提供科学依据.     

零价铁-Fenton试剂体系降解有机污染物的研究进展

零价铁-Fenton试剂体系在对许多有机污染物有着较好的处理效果的同时,有效地克服了单独零价铁还原与传统Fenton反应的缺点.本文分析了零价铁-Fenton试剂体系的作用机理,总结了零价铁-Fenton试剂体系在处理有机污染物中的新进展,介绍了零价铁-Fenton试剂体系与其他技术联用降解有机污染物的研究成果.并讨论了对该反应有较大影响的几种因素.针对目前的研究中出现的一些问题,结合实际的需要,提出了今后需关注的研究方向.     

制定地方污水综合排放标准与实行水污染物排放许可证制度的实践

介绍结合新疆的特殊干旱区生态环境和社会经济,各种污染物因素,试行制定出了本地区地方污水综合排放标准,实行水污染物排放许可证制度的实践体会。     

Environmental assessment of water, sediment and plants in the Mankyeong River, ROK

This study was carried out to evaluate water quality, sediment and plant vegetation in eight tributaries of the Mankyeong River for enhancement of natural purification. Among the tributaries, the Iksancheon water had the highest concentration of BOD, T-N and NH4-N due to inflow of swine wastes from the livestock district. The Yucheon water had the highest level of electrical conductivity and SO4(2-) due to inflow of mis-treated wastewater from industrial districts. The Tabcheon had generally similar concentrations of nitrogen and phosphate to that of the upstream of the Mankyeong River: agricultural activity along the Tabcheon appeared to have little negative influence to the water quality. Among various sediments, concentration of organic matter, nitrogen and phosphate were high in the Iksancheon and the Yucheon due to the livestock wastes and industrial wastes. There were 282 species of plants during summer with 43 aquatic plants, 57 hydrophytes, 178 waterside plants and 4 terrestrial plants. Some plant resources were recommended due to much absorption of nitrogen and phosphate for enhancement of natural purification. C. demersum and H. verticillata were recommended in the submerged aquatic plants, H. dubia, N. indica and N. subinteperrimum in the floating leaf aquatic plants, P. communis, Z. latifolia and T. orientalis in the emerged aquatic plants, C. scutata and P. distichum in the waterside plants.     

Large-volume injection PTV-GC-MS analysis of polycyclic aromatic hydrocarbons in air and sediment samples

For the analysis of trace organic pollutants in environmental samples using a gas chromatographic (GC) instrument, large-volume injection using the programmable temperature vaporization (PTV) technique has many advantages over the traditional split/splitless injection. By increasing the injection volume from 1 or 2 microL with a split/splitless inlet to 60 microL or higher with the PTV inlet, analytical sensitivity is greatly enhanced for analytes with low concentrations. Results obtained from optimization of instrument operational parameters for analyzing polycyclic aromatic hydrocarbons (PAHs) are reported in this paper. The laboratory method detection limits for 16 PAHs and six deuterated PAH surrogates were determined using seven replicate spike samples. The initial temperature of the inlet was found to be critical in determining the analytical sensitivity of PAHs with two or three rings due to loss of these relatively highly volatile compounds during solvent vaporization. For most PAHs, the response of the mass spectrometry detector increased proportionally as the total injected volume was increased up to 150 microL. Significant interference from rubber material of the sample vial septa was observed.     

试论我国道路交通危机管理体系的构建

道路交通危机事件具有意外性、紧急性和危险性等特征,人们在处理过程中往往面临着各种信息不完全、信息不准确或信息反馈不及时等情况,因此,在对整个危机事件的处理过程中都充满了复杂性、快速性等特点。笔者从危机管理角度,提出了道路交通危机和道路交通危机管理的概念;分析了道路交通危机管理的特点以及国内外目前的现状;探讨了在我国建立道路交通危机管理体系的必要性;从道路交通危机管理制度、管理机构、运行机制等方面讨论了构建道路交通危机管理体系的整体框架;从宏观角度重点研究了道路交通危机管理运行机制的预警机制、快速反应机制、信息发布机制、协调机制、评价机制等方面问题。     

黄河下游1996年异常洪水水沙数值模拟

以二维非恒定流和不平衡输沙理论为基础,建立了黄河下游高村至孙口河二维水沙运动数值模型,对１９９６年异常洪水的滩槽水流运动、泥沙冲淤进行了分析计算．计算结果充分反映了模型对黄河来水来沙变幅大的适应能力,以及对滩槽水沙交换、滩区生产堤对洪水演进影响的合理模拟．     

湖北的气候生产力与农业持续发展

基于对湖北省主要农作物气候生产力的估算,分析了目前气候生产力利用的现状,由于受到自然条件和社会条件的限制,在目前大田生产的条件下,湖北粮食气候生产力利用率相对较低,即使是利用率稍高的中稻,其历史最高产量也仅为气候生产力的一半,气候生产潜力较大。因此,如何加强农业气候生产力的开发利用,最大限度的发挥气候资源的作用,将是实现湖北农业持续发展需要解决的重大问题之一。     

旅游文化资源的开发与利用

四川是旅游资源大省，但不是旅游经济强省。要真正把旅游业作为四川省的支柱产业，就必须彻底扭转当前对旅游文化资源的粗放式经营和管理局面。文章通过对四川省和云南省在旅游文化资源的开发，保护，利用和宣传上的不同做法和和态度的比较，总结了云南成功经验，希望从中得到启示。总之，只有实现内涵式旅游开发，把未来旅游吸引力放在自然与文化有机结合的方向上，四川旅游业才能实现可持续发展。