Electrochemical study of the fungicide acibenzolar-s-methyl and its voltammetric determination in environmental samples

The electrochemical behavior of new generation fungicide acibenzolar-s-methyl (S-methyl 1,2,3-benzothiadiazole-7-carbothioate, ASM) on the hanging mercury drop electrode (HMDE) was investigated using square wave adsorptive stripping voltammetry. This method of determination is based on the irreversible reduction of ASM at the HMDE. The well-defined ASM peak was observed at ?0.4 V (vs. Ag/AgCl) in BR buffer at pH 2.2. The reduction peak current was proportional to concentration of ASM from 1.0 × 10^?8 to 6.0 × 10^?8 mol L^?1 with detection and quantification limit 3.0 × 10^?9 and 1.0 × 10^?8 mol L^?1, respectively. The applicability of the developed method for analysis of spiked samples of tap water, river water, and soil is illustrated. The effect of adsorption on the mercury electrode was studied in detail using the AC impedance method. Possible interferences with other common pesticides and heavy metal ions were examined. Clarification of the electrode mechanism was made using cyclic voltammetry (CV) technique.     

Effects of signals of disorder on fear of crime in real and virtual environments

Despite the fact that virtual environments are increasingly deployed to study the relation between urban planning, physical and social disorder, and fear of crime, their ecological validity for this type of research has not been established. This study compares the effects of similar signs of public disorder (litter, warning signs, cameras, signs of vandalism and car burglary) in an urban neighborhood and in its virtual counterpart on the subjective perception of safety and livability of the neighborhood. Participants made a walking tour through either the real or the virtual neighborhood, which was either in an orderly (baseline) state or adorned with numerous signs of public disorder. During their tour they reported the signs of disorder they noticed and the degree to which each of these affected their emotional state and feelings of personal safety. After finishing their tour they appraised the perceived safety and livability of the environment. Both in the real and in the simulated urban neighborhood, signs of disorder evoked associations with social disorder. In all conditions, neglected greenery was spontaneously reported as a sign of disorder. Disorder did not inspire concern for personal safety in reality and in the virtual environment with a realistic soundscape. However, in the absence of sound disorder compromised perceived personal safety in the virtual environment. Signs of disorder were associated with negative emotions more frequently in the virtual environment than in its real-world counterpart, particularly in the absence of sound. Also, signs of disorder degraded the perceived livability of the virtual, but not of the real neighborhood. Hence, it appears that people focus more on details in a virtual environment than in reality. We conclude that both a correction for this focusing effect and realistic soundscapes are required to make virtual environments an appropriate medium for both etiological (e.g. the effects of signs of disorder on fear of crime) and intervention (e.g. CPTED) research.     

基于宜居视角的居住城市化水平测度——以大连市为例

从宜居的视角出发,结合大连市发展现状建立居住城市化水平测度指标体系,利用模糊层次分析法（AHP）确定指标权重,计算居住城市化水平测度综合指数。通过整理样本社区测度综合指数的数据,建立指标数据库,利用地理信息系统软件MapInfo 10进行格网赋值,构建基于空间插值法的居住城市化水平测度模型,绘制大连居住城市化水平测度专题图,直观展现大连市居住城市化水平发展的时空变化特征。结果表明,1995—2010年大连市居住城市化发展呈现出由整体发展水平低、内部差异小到发展速度提高、地域发展不均衡,再到发展速度减慢,日趋平衡,最后实现发展速度再次提高、均衡发展、差异减小的阶段特征。     

基于层次分析法的古村落旅游资源评价——以世界遗产地西递、宏村为例

以世界遗产地皖南古村落——西递、宏村为研究区域,从研究区域的资源价值和区位条件两个方面,选取了5个Ⅰ级指标：历史文化价值、科学价值、艺术价值、区域规模、交通便利程度,12个Ⅱ级指标：年代久远程度、民俗代表性、历史事件名人影响度、科学考察、科普教育、完整性、典型性、观赏性、地域组合、环境容量、通达性与服务中心距离,建立评价指标体系,并结合YAAHP软件对该指标体系进行层次分析,得出了各指标的相对权重。结果表明,西递、宏村的历史文化价值与艺术价值在其旅游资源评价中具有重要地位。在此基础上对其进行了分析并提出了相应的保护措施和对策,以期达到对西递、宏村旅游资源合理保护与开发的目的。     

黑龙江省东部煤电化基地经济与生态环境协调发展评价研究

构建东部煤电化基地是继哈大齐工业走廊启动建设后,黑龙江省做出的一项重大战略部署。基地建设要求深入贯彻科学发展观,大力发展煤化工产业,实现全面、协调、可持续发展。全面协调发展不仅是经济的发展,同时也要考虑生态环境的保护。运用层次分析法和协调发展度模型,研究黑龙江东部煤电化基地经济和生态环境的协调发展程度表明,黑龙江东部煤电化基地经济和生态环境协调发展水平处于中等协调状况。针对评价结果,提出了相应的对策和建议。     

阿坝州大骨节病和扶贫开发决策中AHP方法的应用

大骨节病防治和扶贫开发试点工作涉及阿坝州的经济、社会、生态等各方面,且州内各县、乡、村情况各异,众多具体措施关系复杂。为了提高决策质量,使试点工作取得“优化举措、重点突破”的效果,应用AHP方法建立了定量模型。     

基于排队论的城市垃圾箱最佳间距研究

针对城市垃圾箱最佳间距的研究不够精细的现状,本文通过建立排队论模型得到了可供不同城市参考的城市垃圾箱最佳间距参数表。通过对部分城市街道的垃圾箱摆放间距情况进行实地调查,运用层次分析法将影响垃圾箱间距分布的多重因素转化为单因素;建立了基于指数分布的数学模型,利用排队论分析单因素状态下的垃圾箱间距分布,得到了求解城市垃圾箱最佳间距的一般方法。     

振动试验数据管理系统概述

随着近些年振动试验技术的快速发展,对于振动试验数据的保存、管理和统计提出了更高的要求。鉴于此,附属于试验室信息管理系统的振动试验数据管理系统作为振动试验有效的管理工具,必然会成为提升试验室振动试验能力、规范试验技术的有效工具。     

Is Urban Stream Restoration Worth It?1

Kenney, Melissa A., Peter R. Wilcock, Benjamin F. Hobbs, Nicholas E. Flores, and Daniela C. Martínez, 2012. Is Urban Stream Restoration Worth It? Journal of the American Water Resources Association (JAWRA) 48(3): 603-615. DOI: 10.1111/j.1752-1688.2011.00635.x Abstract: Public investment in urban stream restoration is growing, yet little has been done to quantify whether its benefits outweigh its cost. The most common drivers of urban stream projects are water quality improvement and infrastructure protection, although recreational and aesthetic benefits are often important community goals. We use standard economic methods to show that these contributions of restoration can be quantified and compared to costs. The approach is demonstrated with a case study in Baltimore, Maryland, a city with a legal mandate to reduce its pollutant load. Typical urban stream restoration costs of US$500-1,200 per foot are larger than the cost of the least expensive alternatives for management of nitrogen loads from stormwater (here, detention ponds, equivalent to $30-120 per foot of restored stream) and for protecting infrastructure (rip-rap armoring of streambanks, at $0-120 per foot). However, the higher costs of stream restoration can in some cases be justified by its aesthetic and recreational benefits, valued using a contingent valuation survey at $560-1,100 per foot. We do not intend to provide a definitive answer regarding the worth of stream restoration, but demonstrate that questions of worth can be asked and answered. Broader application of economic analysis would provide a defensible basis for understanding restoration benefits and for making restoration decisions.     

Anaerobic degradation of microcrystalline cellulose: kinetics and micro-scale structure evolution

The degradation kinetics and micro-scale structure change of microcrystalline cellulose during anaerobic biodegradation were investigated. A modified Logistic model was established to properly describe the kinetics, which showed good fitness and wide applicability for cellulose degradation. A maximum degradation rate of 0.14 g L⁻¹ h⁻¹ was achieved after cultivating for 51.5 h. This result was in good agreement with the scanning electron microscope and X-ray diffraction analysis. Channels of 400-500 nm size started to occur on the crystalline surface of cellulose at around the inflexion time. Accordingly, the crystallinity significantly decreased at this point, indicating a degradation of the crystalline structure zones by anaerobic bacteria. This study offers direct morphological evidence and quantitative analysis of the biodegradation process of cellulose, and is beneficial to a better understanding of the cellulose degradation mechanism.