酸雨浸泡作用下云南红土的剪切特性

根据云南省酸雨特点配制模拟酸雨溶液,考虑时间、pH值两个因素,采用浸泡的试验方法,研究酸雨作用下云南红土抗剪特性变化,最后对酸雨-红土间的作用机理进行分析.试验结果表明,总体上酸雨浸泡降低了红土的抗剪强度及其特征参数.酸雨pH越小,浸泡时间越长,红土抗剪强度折减越多;抗剪强度及其特征参数随pH值增大而波动增大,质量随pH值增大而先减小后增大;浸泡第1 d时,红土抗剪强度及其特征参数折减幅度最大,之后随浸泡时间增加而波动变化,质量随浸泡时间增加而波动减小;为解释上述几个结果,特对酸雨-红土相互作用过程进行分析,将其归结为酸雨-红土物理作用、酸雨-红土化学作用、酸雨-红土盐类溶解、置换、结晶等.     

抗生素与重金属对蛋白核小球藻时间依赖协同作用的动态定量表征

以硫酸阿米卡星(Amikacin sulfate, AMI)、五水合氯化镉(CdCl₂·2.5H₂O, Cd)、四水合氯化锰(MnCl₂·4H₂O, Mn)和七水合硫酸锌(ZnSO₄·7H₂O, Zn)为研究对象,以蛋白核小球藻(Chlorella pyrenoidosa, C. pyrenoidosa)为指示生物,采用均匀设计射线法设计3组二元混合体系(AMI-Cd、AMI-Mn和AMI-Zn),并应用时间毒性微板分析法测定其对C. pyrenoidosa的毒性数据,以浓度加和模型(Concentration addition, CA)和独立作用模型(Independent action, IA)为标准加和模型进行毒性相互作用分析,并运用效应残差比(Effect residual ratio, ERR)进行定量动态表征毒性相互作用。结果表明,3组二元混合体系共十五条射线的混合毒性呈明显的时间依赖性和浓度依赖性;依据ERR,CA和IA对三组二元混合体系的毒性评估结果基本一致,但3个混合物体系的毒性相互作用具有不同的时间变化规律,即随暴露时间延长,AMI-Cd中五条射线的中浓度区由协同作用逐渐变为加和作用,AMI-Zn中5条射线在高浓度区的协同作用逐渐变为加和作用,而中低浓度区的协同作用在加强;AMI-Mn的毒性相互作用随时间变化不是很明显;与CA和IA相比,ERR定量地表征了混合物体系的毒性相互作用强度,这为客观和准确地评估污染物的环境风险提供了方法和数据参考。     

环境微塑料与有机污染物的相互作用及联合毒性效应研究进展

环境微塑料可吸附有机污染物,并与有机污染物进行相互作用从而改变其毒性效应,增加微塑料的治理难度.本文就全球范围内微塑料与有机污染物的相互作用及毒性效应的研究进展进行综述,分析不同介质中微塑料与有机污染物的共存水平、吸附机理、影响因素以及联合毒性效应等.研究表明,微塑料可作为多环芳烃(PAHs)、多氯联苯(PCBs)、六...     

Reduction of Cr(VI) by peat and coal humic substances

The reduction of Cr(VI) by humic substances from leonardite and peat was investigated by capillary zone electrophoresis at various pHs. Both humic materials reduced Cr(VI) at pH 5.4, but not at basic pH. The capacity of leonardite humic substances to reduce Cr(VI) was lower than that of peat humic substances. Fe(III) accelerated the reduction of Cr(VI) by peat humic substances, but not by leonardite humic substances. Cr(VI) reduction mechanisms are proposed. The coal humic substances seem more suitable for remediation of Cr(VI)-contaminated sites.     

新疆寒区矿山重金属元素在冰雪冻融作用下的富集转化机理研究进展

冰川和雪山融水是新疆极为重要的水源补给来源,对区域社会经济可持续健康发展发挥着至关重要的作用.寒区矿山典型的冷热双岛效应会导致矿山重金属粉尘向外扩散,而冰雪冻融循环又为重金属元素富集转化提供了必要的环境,使得重金属元素随融水进入下游河流,对河流流经地区的人类生产生活及生态系统产生严重影响.为探究重金属元素在此冰雪冻融过程中的富集转化机理,本文综述了近年来有关重金属元素富集转化及其先导环节的研究进展,分别介绍了矿山粉尘运移扩散、矿山粉尘覆盖下的冰川消融以及重金属元素富集转化的国内外研究现状,并对新疆高寒地区矿山重金属元素在冰雪冻融作用下的富集转化机理研究的发展前景和应用价值进行了展望.     

Use of an Action‐Selection Framework for Human‐Carnivore Conflict in the Bangladesh Sundarbans

Abstract: Human–carnivore conflict is manifested in the death of humans, livestock, and carnivores. The resulting negative local attitudes and retribution killings imperil the future of many endangered carnivores. We tailored existing management tools to create a framework to facilitate the selection of actions to alleviate human–carnivore conflict and applied the framework to the human–tiger conflict in the Bangladesh Sundarbans. We identified potential actions that consider previous management efforts, local knowledge, cost‐effectiveness, fieldwork experience of authors and project staff, previous research on tiger ecology by the authors, and recommendations from human–carnivore conflict studies in other countries. Our framework includes creation of a profile to improve understanding of the nature of the conflict and its underlying causality. Identified actions include deterrents, education, direct tiger management, and response teams. We ranked actions by their potential to reduce conflict and the monetary cost of their implementation. We ranked tiger‐response teams and monitoring problem tigers as the two best actions because both had relatively high impact and cost‐effectiveness. We believe this framework could be used under a wide range of human–wildlife conflict situations because it provides a structured approach to selection of mitigating actions.     

Ecosystems emerging. 5: Constraints

Ecosystem constraints are both ontic and epistemic. They limit activity, and as problems to be solved they drive organization, which is our hypothesis:

The driver of organization is constraint.

Solutions proliferate further constraints in an unending spiral of problem (constraint) generation and solution. As constraints proliferate, behavior narrows, and species diversify to compensate (paradox of constraint). Resource enrichment reduces constraints, releases behavior, and reduction of challenges decreases diversity (paradox of enrichment)—high diversity is expressed in low-resource environments and low diversity in high-resource environments. A three-part model of constraints is formulated for non-living systems, and also for goal-directed, problem-solving biota. Mode 1: dynamical means behavior is co-determined by internal states and external inputs. Mode 2: cybernetic employs negative feedback to keep dynamics within goal-oriented operating limits. Mode 3: model-making entails ability to represent (model) physical reality and respond to both phenomenal (modeled) and physical inputs; this property distinguishes living from nonliving systems. Principal sections of the paper elaborate dynamical constraints (three classes), boundary constraints (expressed in edge effects and trophic dynamics), physical constraints (space, time, temperature), chemical constraints (environment fitness, ecological stoichiometry, chemical evolution, limiting factors), coding constraints (environmental vs. genetic coding), network and pathway constraints (connectivity), and natural selection constraints (fitting to the biosphere). Consideration of how the world would look without constraints suggests how fundamental these are in ecosystem emergence, and how the next property in this series, differentiation, would be unmotivated without them. We conclude that constraints as a category are under-studied in ecology, poorly understood in ecological phenomenology, and (our hypothesis) comprise a ubiquitous organizing force in nature.     

Another avenue of action: an examination of climate change countermovement industries’ use of PAC donations and their relationship to Congressional voting over time

The political mobilization of American business elites in the 1970s and 1980s has been well studied by political scientists. Environmental sociologists have explored how industries in this elite countermovement have organized to prevent environmental legislation. The literature often focuses on the efforts of this movement to shape public opinion on climate change. However, political scientists argue business elites are running several parallel strategies simultaneously in order to protect their interests. FEC data are utilized in multilevel logit models to examine how donations from industrial Political Action Committees (PACs) relate to Congressional representative’s environmental voting behavior over a 20-year period. Industries associated with the environmental countermovement have increasingly used PAC donations over time, and every additional $10,000 a representative received from countermovement industries significantly decreased odds of their taking the pro-environmental stance even when controlling for representatives’ demographics, districts, Congressional polarization and time-period.     

气相色谱法测定空气和废气中8种烃类化合物

建立了针筒采样、大口径毛细管柱分离、气相色谱-氢火焰离子化检测器测定空气和废气中甲烷、乙烷、乙烯、乙炔、丙烷、异丁烷、正丁烷和正戊烷等8种烃类化合物的方法.优化了试验条件,方法线性良好,甲烷、乙烯、乙炔、乙烷、丙烷、异丁烷、正丁烷和正戊烷的检出限分别为0.09 mg/m3、0.20 mg/m3、0.18 mg/m3、0.29 mg/m3、0.28 mg/m3、0.37 mg/m3、0.16 mg/m3和0.56 mg/m3,RSD＜8.0%,加标回收率为80.5%～104%.