湖沼型血吸虫病疫区钉螺空间自相关的样点尺寸效应

钉螺是血吸虫的唯一中间宿主,与众多地理因子一样,钉螺的空间自相关具有明显的尺度效应。在湖沼型血吸虫病疫区典型洲垸型草洲选择一块50 m×50 m的试验样地,采用推扫式全覆盖方法进行了钉螺普查。用全局空间自相关Moran I指数、局部空间自相关Moran散点图和局部Moran’s I指数,进行了钉螺分布空间自相关的样点尺寸效应研究。结果表明:所有样点尺寸钉螺数目的全局Moran’s I均为极显著空间正相关(P0.001);不同样点尺寸下的钉螺样点在局部自相关Moran散点图上绝大多数集中分布在象限1和象限3内,表明试验样地的钉螺呈空间聚集分布;钉螺样点尺寸越小,用局部Moran’s I指数对单个钉螺样点附近的空间自相关表现得越细微,表明全局Moran’s I指标会掩盖实际存在的局部空间自相关与全局不一致的现象。     

Credible Enforcement Policies Under Illegal Fishing: Does Individual Transferable Quotas Induce to Reduce the Gap Between Approved and Proposed Allowable Catches?

In general, approved Total Allowable Catches (TACs) are higher than proposed TACs by the scientific assessment and reported landings approved are higher than approved TAC. We build a simple enforcement agency’s behavior model that generates—as a rational behavior—those two facts. The model has two ingredients. First, there exists illegal fishing generated by an imperfect enforcement technology; second, the enforcement agency cannot commit on announced penalties. We show that lack of commitment increases the potential benefits for national enforcement agency of deviating from proposal (scientific optimal) quotas. Although the enforcement agency wants to announce a low quota target to induce a low level of illegal harvest, it will find optimal to revise the quota announced in order to reduce penalties and improve fishermen welfare. Therefore, agencies find it optimal to approve higher quotas than that proposed by the scientific advice. Our main result is to show that when full compliance is not possible, and national agencies cannot commit, the introduction of Individual Transferable Quotas increases the potential benefits for agencies of deviating from the optimal proposed TAC by the scientific advised.     

Surrogate Model-Based Simulation-Optimization Approach for Groundwater Source Identification Problems

This study investigates and discusses a time-efficient technology that contains a surrogate model within a simulation-optimization model to identify the characteristics of groundwater pollutant sources. In the proposed surrogate model, Latin hypercube sampling (a stratified sampling approach) and artificial neural network (commencing at the stress period when the concentration is within a certain range, and ending at the peak time) were utilized to reduce workload and costly computing time. The results of a comparison between the proposed surrogate model and the common artificial neural network model and non-surrogate model indicated that the proposed model is a time-efficient technology which could be used to solve groundwater source identification problems.     

Arsenic detoxification potential of <Emphasis Type="Italic">aox</Emphasis> genes in arsenite-oxidizing bacteria isolated from natural and constructed wetlands in the Republic of Korea

Arsenic is subject to microbial interactions, which support a wide range of biogeochemical transformations of elements in natural environments such as wetlands. The arsenic detoxification potential of the bacterial strains was investigated with the arsenite oxidation gene, aox genotype, which were isolated from the natural and constructed wetlands. The isolates were able to grow in the presence of 10 mM of sodium arsenite (As(III) as NaAsO₂) and 1 mM of d+glucose. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that these isolated strains resembled members of the genus that have arsenic-resistant systems (Acinetobacter sp., Aeromonas sp., Agrobacterium sp., Comamonas sp., Enterobacter sp., Pantoea sp., and Pseudomonas sp.) with sequence similarities of 81–98%. One bacterial isolate identified as Pseudomonas stutzeri strain GIST-BDan2 (EF429003) showed the activity of arsenite oxidation and existence of aoxB and aoxR gene, which could play an important role in arsenite oxidation to arsenate. This reaction may be considered as arsenic detoxification process. The results of a batch test showed that P. stutzeri GIST-BDan2 (EF429003) completely oxidized in 1 mM of As(III) to As(V) within 25–30 h. In this study, microbial activity was evaluated to provide a better understanding of arsenic biogeochemical cycle in both natural and constructed wetlands, where ecological niches for microorganisms could be different, with a specific focus on arsenic oxidation/reduction and detoxification.     

某润滑油污染场地健康风险评估

总石油烃(total petroleum hydrocarbons, TPH)是烃总量的一个表征,包含各种烃类化合物,对人体具有极大的危害.通过对四川省某润滑油厂拆迁场地采样调查,分析了污染物分布特征,在明确未来规划用途的条件下,用分馏法以高碳石油烃毒性参数对污染地块的石油烃进行了风险评估.结果表明,场地主要污染物为石油烃C10～C40,主要污染区域为生产车间、室外原油堆放区、油桶堆放区、油罐堆放区和废水处理池.不同功能区石油烃C10～C40垂直分布特征不同,同一土壤层不同功能区域石油烃C10～C40污染程度也不同.对不同组成成分的石油烃C10～C40进行风险评估,其评价结果也不同.总的来说HI(脂肪族∶芳香族含量比为100∶0)＜HI(脂肪族∶芳香族含量比为79.4∶20.6)＜HI(脂肪族∶芳香族含量比为0∶100).当脂肪族∶芳香族含量比为100∶0和79.4∶20.6时,石油烃C10～C40总危害商＜1,石油烃C10～C40浓度在人体健康可接受的范围内,不需要进行土壤风险控制值计算;当脂肪族∶芳香族含量比为0∶100时,石油烃C10～C40总危害商＞1,存在非致癌风险;综合非致癌效应的土壤风险控制值为8 168.58 mg·kg-1 .     

外源稀土在根际与非根际土壤中的存在形态

采用根际袋法研究了稀土在春小麦根际土壤与非根际土壤中存在形态的差别.结果表明,外源稀土进入土壤后,在根际土壤与非根际土壤中主要以残渣态形式存在,各形态含量的大小顺序为:残渣态>碳酸盐结合态>可交换态>铁锰氧化物结合态>有机质结合态.小麦根系活动明显影响根际土壤中的稀土存在形态,根际土壤中的可交换态和铁锰氧化物结合态含量明显大于非根际土壤中的含量,而碳酸盐结合态有所下降,有机质结合态无明显变化.     

智能交通安全系统的研究

随着智能交通系统概念的提出 ,在交通领域中 ,该系统已得到了极大的发展和应用 ,同时对世界各国城市交通的发展起了极大的推动作用。而在交通的发展过程中 ,交通安全始终是第一重要的 ,智能交通安全系统是智能交通系统的重要组成部分。笔者研究和探讨了智能交通安全系统的概念、组成及自动事件管理系统、可变信息标志系统、自动化的商业车辆系统、在智能交通中所起的重要作用 ,并介绍了美国的一些经验     

用141Ce示踪研究小麦对稀土的吸收速率和积累规律

应用¹⁴¹Ce,采用水培的方法研究冬小麦对稀土元素的吸收和分配规律及铈在水-植物界面间的传输速率.结果表明,在实验期内,冬小麦幼苗中铈的浓度随培养时间的延长而增加,随培养液中铈浓度的提高而增加;铈在冬小麦各器官中的浓度,根部的远大于在茎叶中的;吸收速率是较高浓度处理的要高于较低浓度处理的,并且在不同培养期中的吸收速率是不相同的.对冬小麦的吸收速率随时间的变化规律进行了拟合,给出了定量描述公式.     

试论环境保护投资与环保产业的发展

本文针对国内学术界和政府部门在环境保护产业投资和环境保护投资方面的模糊认识,明确区分了环保投资与环保产业投资,阐释了狭义的环保投资概念和环保投资与环保产业市场化的关系,论述了环保投资对环保产业市场化的作用,并强调只有坚持以市场为导向,环保产业才能健康发展,本文还论述了在拓展市场业务的过程中,受需求牵引,环保产业必然会由以末端治理服务为主转向为企业生产全过程的服务为主,最终融于生产过程而转化为清洁生产行为或产品生命周期管理。     

室内空气中的化学农药及其检测技术

室内空气中化学农药之所以存在 ,主要因为我们在杀灭室内蚊、蝇、蚤、蚂蚁、蟑螂及老鼠时 ,使用了含化学农药的杀虫剂。目前 ,我国市场上流通的含有化学农药的杀虫剂商品近 1 0 0 0种 ,但从农药的有效成分来看 ,大约有 60余种。它们多属拟除虫菊酯类农药 ,占总数的 50 % ;此外还有氨基甲酸酯类、有机磷类农药等。本文重点介绍室内空气中化学农药的捕集及检测技术