基于RS/GIS的武汉市九峰城市森林保护区景观结构特征及规划对策

大型的城市森林绿地是城市生态框架的重要组成部分,其景观结构的优化有助于城市生态系统结构与功能稳定。九峰城市森林保护区是武汉近郊最大的森林绿地。应用快鸟遥感影像并结合实地调查,在RS和GIS的支持下对九峰城市森林保护区的景观结构进行了分析,并探讨了森林景观的规划对策。结果表明：九峰城市森林保护区景观分为林地、农耕地、苗圃地、水域、建设用地、墓地、荒地、草地和裸岩9个景观类型,263个斑块,其中林地最多,占总面积的36.56%,占斑块总数的8.75%,为景观基质,但对景观过程的控制作用不强。建设用地和农耕地斑块形状最为复杂,易造成人类活动干扰的扩散。林地成片分布,破碎化程度较低,连通性较高,有利于其资源保护。九峰城市森林保护区表现出整体结构简单,局部结构复杂的特征。针对这些景观结构特征,提出了大幅提高林地比例,压缩建设用地和其他人类活动明显的景观类型面积,构建聚集间有离析的空间优化格局,加强荒地和裸岩的植被恢复,设置“踏脚石”斑块和建立保护性廊道的景观优化对策,以期为九峰城市森林保护区的规划与管理提供依据。     

Effect of salt and urban water samples on bacterivory by the ciliate, Tetrahymena thermophila

The effect of road salt on the eating of bacteria or bacterivory by the ciliate, Tetrahymena thermophila, was followed in non-nutrient Osterhout's solution with Escherichia coli expressing green fluorescent protein. Bacterivory was impaired at between 0.025 and 0.050% w/v but the ciliates appeared to have normal morphologies and motilities, whereas at above 0.1%, bacterivory was blocked and many ciliates died. By contrast, E. coli remained viable, suggesting salt could alter predator-prey relationships in microbial communities. In nutrient medium, salt was not toxic and the ciliates grew. After growth in salt, ciliates consumed bacteria in 0.2% salt, indicating the salt acclimation of bacterivory. Bacteria and ciliates were added to urban creek samples to compare their capacity to support exogenous bacterivory. Even though samples were collected weekly for a year and be expected to have fluctuating salt levels as a result of deicing, all creek samples supported a similar level of bacterivory.     

Tritium concentrations in the atmospheric environment at Rokkasho, Japan before the final testing of the spent nuclear fuel reprocessing plant

This study aimed at obtaining background tritium concentrations in precipitation and air at Rokkasho where the first commercial spent nuclear fuel reprocessing plant in Japan has been under construction. Tritium concentration in monthly precipitation during fiscal years 2001-2005 had a seasonal variation pattern which was high in spring and low in summer. The tritium concentration was higher than that observed at Chiba City as a whole. The seasonal peak concentration at Rokkasho was generally higher than that at Chiba City, while the baseline concentrations of both were similar. The reason for the difference may be the effect of air mass from the Asian continent which is considered to have high tritium concentration. Atmospheric tritium was operationally separated into HTO, HT and hydrocarbon (CH₃T) fractions, and the samples collected every 3 d-14 d during fiscal year 2005 were analyzed for these fractions. The HTO concentration as radioactivity in water correlated well with that in the precipitation samples. The HT concentration was the highest among the chemical forms analyzed, followed by the HTO and CH₃T concentrations. The HT and CH₃T concentrations did not have clear seasonal variation patterns. The HT concentration followed the decline previously reported by Mason and Östlund with an apparent half-life of 4.8 y. The apparent and environmental half-lives of CH₃T were estimated as 9.2 y and 36.5 y, respectively, by combining the present data with literature data. The Intergovernmental Panel on Climate Change used the atmospheric lifetime of 12 y for CH₄ to estimate global warming in its 2007 report. The longer environmental half-life of CH₃T suggested its supply from other sources than past nuclear weapon testing in the atmosphere.     

城市居民区配套设备噪声频率特性分析

对绵阳市某居住区典型的配套设备噪声源进行分析,选取变配电房噪声、车库噪声、电梯井噪声、电梯控制室噪声、家用空调室外机、水泵房等6种典型噪声源。分析这些噪声源的频谱及低、中、高频段的能量比率。结果表明,各声源最大声压级所在频段以低频段最多（6种典型噪声中占5种）,最大能量分布频段也是以低频段最多（6种典型噪声中占5种）,因而低频噪声已经成为居住区中影响最大的噪声源。     

Light distribution in dynamic street lighting: Two experimental studies on its effects on perceived safety,prospect, concealment,and escape

The relationship between light and perceived safety at night is intuitively strong, yet theoretically and empirically its workings are largely unknown. Intelligent dynamic road lighting, which continuously adapts to the presence and behavior of users, can light the street only when and where it is needed. As such, it offers a solution to the energy waste and luminous pollution associated with conventional road lighting. With this innovation, however, new questions emerge about the effect of lighting on perceived safety. We need to consider not only how much lighting pedestrians need to feel safe, but also which parts of the street should be lit. In two experiments, we investigated the effect of different light distributions on perceived safety, and explored mediation by people's appraisal of three safety-related cues suggested in the literature: prospect (having an overview), escape (perceived escape possibilities), and refuge/concealment (perceived hiding places for offenders). Both experiments, one with stationary and one with walking participants, demonstrated that people prefer having light in their own immediate surroundings rather than on the road that lies ahead. This could be explained, partially, by changes in prospect, escape, and concealment. Against expectations, prospect was higher with lighting distributions in which participants' immediate surroundings, but not the more distant parts of the road, were most strongly lit.     

环境政策对企业绩效的影响

一个国家的环境政策是国家保护环境的大致方针,直接关系到这个国家的环境立法和环境管理,更直接影响到这个国家的整体环境状况,不同类型的环境政策对企业也产生了各方面的影响。本文研究环境政策的不同形式、内容、具体执行手段及其对企业的环境、经济绩效产生的影响。通过研究西方发达国家的成功环境政策,探讨我国环境政策中存在的不足与缺陷。最后根据不同管理手段的可行性,有效性及最终效果,联系我国具体国情,在符合可持续发展原则的同时,提出更为有效,对企业绩效具有正面刺激的环境政策建议。     

大型燃煤电站电袋复合除尘器的应用研究

对大型燃煤电站电一袋复合除尘技术进行了较全面的分析研究,如气流组织最优方案确定、脉冲喷吹系统选型及参数优化、粉尘荷电对滤料阻力的影响及高压电源的优选等。研究表明对电袋复合除尘器来说,袋式除尘区采用阶梯式布置是一种较为理想的气流组织方式,活塞式脉冲阀具有更好的清灰性能,粉尘的荷电有助于减小除尘设备的阻力,三相电源的性能优于单相电源。     

乌鲁木齐城市小区雨水收集回用系统设计建议——以晨光-佳苑为例

运用城市小区雨水资源收集回用系统成为了城市节约水资源新的途径。分析了乌鲁木齐晨光-佳苑住宅小区原有雨水收集回用状况,建议采用雨水入渗技术,对原有设计系统进行改造,增加新的雨水收集回用系统,探讨改造小区雨水收集回用系统的可行性,提出完善新增雨水收集回用系统的建议。     

Planetary Stewardship in an Urbanizing World: Beyond City Limits

Cities are rapidly increasing in importance as a major factor shaping the Earth system, and therefore, must take corresponding responsibility. With currently over half the world’s population, cities are supported by resources originating from primarily rural regions often located around the world far distant from the urban loci of use. The sustainability of a city can no longer be considered in isolation from the sustainability of human and natural resources it uses from proximal or distant regions, or the combined resource use and impacts of cities globally. The world’s multiple and complex environmental and social challenges require interconnected solutions and coordinated governance approaches to planetary stewardship. We suggest that a key component of planetary stewardship is a global system of cities that develop sustainable processes and policies in concert with its non-urban areas. The potential for cities to cooperate as a system and with rural connectivity could increase their capacity to effect change and foster stewardship at the planetary scale and also increase their resource security.     

What’s the Problem? River Management,Education, and Public Beliefs

This paper invokes the theory of planned behavior (TPB) as a diagnostic tool to explain an existing public education program's limited success at improving river water quality in the City of Perth, Western Australia. A reflective, client-driven research approach was used. A facilitated expert workshop defined an environmental problem (excess nutrients leaving gardens and entering waterways) and a desired behavior (residents purchasing environmentally sensitive fertilizer) to address the problem. A TPB-based belief elicitation survey captured respondents' beliefs regarding the desired behavior. The findings suggest respondents were aware of the links between purchasing environmentally sensitive fertilizer and river water quality. However, this behavior is compromised by the challenges in identifying appropriate products, product quality concerns, and cost. Viewing the content of a public education program through the lens of the TPB reveals insights into how and why the program fell short in achieving one of its key behavioral change goals.