高活性絮凝剂产生菌群的构建、培养及应用研究

从筛选到的絮凝剂产生菌中构建出能比单一菌群产生更高絮凝活性的复合菌群———复合菌群1(BAFRT4+CYGS1).为降低复合菌群1的培养成本,尝试用啤酒废水替代葡萄糖作为培养基中的碳源和能源并获得成功.在优化培养条件下,复合菌群1所产MBF的絮凝活性达96.8%.复合菌群1所产MBF对靛蓝印染废水有良好的处理效果,最大CODCr去除率和脱色率分别达79.2%和87.6%.     

基于观测数据空间化的北京市PM_(2.5)时空分异

PM2.5在地球表面上的变化是连续的,但由于地面海拔起伏和站点分布的相对稀疏,直接内插法很难顾及这种情况。文章运用反距离权重(IDW)、Kriging、经验贝叶斯克里金法(EBK)、多元回归+残差内插的综合空间化手段,对北京市2015年1月的PM2.5数据进行分析。结果表明:利用多元回归+残差内插方法空间化更优,且PM2.5存在显著的正局部空间自相关,中度以上污染主要分布在北京市东南部和房山区。时间上,PM2.5质量浓度逐时均值呈\"W\"型。3 h尺度上,PM2.5质量浓度与相对湿度和露点温度正相关,与能见度、大气压和风速负相关,与温度不相关。     

The influence of caste,class and gender in surviving multiple disasters: A case study from Orissa,India

Sociological and anthropological studies in India reveal that caste, class and gender in everyday life are both rigid and dynamic, but little is known about how they influence the survival mechanisms of women during ‘multiple disasters’, nor about how women negotiate with these structural mores to meet their cultural and biological needs. This is explored through the experiences of 12 women-headed households from different social castes in Orissa, India. Multiple disasters or disasters that occur in ‘one specific place’ (such as floods, cyclone and drought) are regular events in coastal parts of the state of Orissa. The super-cyclone of 1999, two floods of 2001 and 2003 and drought of 2000 and 2002 form the case study. Participant observation, in-depth interviews and documentary evidence complement the fieldwork. The findings suggest a complex interplay of caste, class and gender in surviving the multiple disasters including structural mutability under the purview of social organization. In doing so, women demonstrated their individual and collective agencies in order to meet their cultural and biological needs under severe crisis. This research stresses that gender and disaster studies must include a consideration of caste and class for effective disaster management and social vulnerability reduction.     

Linking the stressors and stressing the linkages: Human—environment vulnerability and brownfield redevelopment in New York City

This paper suggests that the mitigation of one hazard—soil contamination—can unintentionally affect vulnerabilities and perceived vulnerabilities to additional stressors in the local human—environment system through a study of brownfield redevelopment in New York City. This study employs a Vulnerability Scoping Diagram (VSD) approach to identify components that contribute to vulnerabilities and perceived vulnerabilities in the local community, based on the thematic analysis of 55 interviews with residents from four neighbourhoods with brownfield redevelopment activities in New York City. This analysis of resident observations and perceptions of post-redevelopment hazard conditions indicates how mitigating vulnerability to one urban hazard—soil contamination—has the potential to affect vulnerabilities and perceived vulnerabilities to additional hazards like flooding and air pollution because of the complex linkages among multiple stressors. A causal model of vulnerability to the unintended impacts of brownfield redevelopment is subsequently developed to further demonstrate the interactive linkages among exposure, sensitivity and adaptive capacity to multiple stressors. This study also provides measures that stakeholders can monitor and evaluate over time to track the socio-spatial and environmental implications of brownfield redevelopment and subsequent changes in the local human—environment system.     

363kV快速真空断路器电场计算

高电压等级开关设备的绝缘水平严重影响设备的安全运行和开断能力,因此在研发高电压真空断路器时需要分析其电场分布。以363 kV快速真空断路器设计结构为原型,建立三维有限元电场计算模型,分别计算了额定电压下闭合和开断工况下的电场分布,分析了灭弧室、绝缘子以及主要金具表面的电场大小。结果表明:均压环表面电场最大值为1.92 MV/m,绝缘子表面最大值为0.36 MV/m,开距20 mm时灭弧室断口电场最大值为3.5 MV/m,其他部位电场均处于控制范围内,断路器总体结构设计合理,满足绝缘要求。     

Large-scale mercury variations in Lake Vänern (Sweden) 1974-98

Lake V?nern, the largest lake in Sweden, has been seriously contaminated with mercury during the 20th century. In the 1970's and 80's the direct load, mainly from a chlor-alkali industry in the area, of mercury was drastically reduced as a response to new legislation, from three to five tons down to between five and ten kg yr(-1). Large amounts of the disposed pollutant have accumulated in the sediments. The question posed in this work is now, is the effect of the drastic load reduction after more than two decades visible in the sediments? The question is relevant as large areas still are blacklisted for fishing, but also as a follow-up of a major remedy action. The lake also serves as a freshwater reservoir for even Sweden's second largest city. This work synthesises and compares data of mercury in the sediments from three major field programs, in 1974, 1984 and 1998. The interest is focused on both spatial heterogeneity and temporal trends. In 1974, the surface concentrations are significantly higher than in subsequent surveys. Significant differences are also found between 1984 and 1998. Significant spatial differences within the lake are found for respective year. The most contaminated area is located in the north, close to the major point source (a former chlor-alkali industry). This is also the area with the largest improvement, as a direct response to the reduction in load. Further from the outlet, the recovery is more affected by burial and transport processes out into the deeper basins.     

Modeling the spatial pattern of farmland using GIS and multiple logistic regression: a case study of Maotiao River Basin, Guizhou Province, China

Land use change is an important topic in the field of global environmental change and sustainable development. Land use change modeling has attracted substantial attention because it helps researchers understand the mechanisms of land use change and assists regulatory bodies in formulating relevant policies. Maotiao River Basin is located in the province of Guizhou, China, which has a developed agricultural industry in the karst mountain areas. This paper selected biophysical and social–economic factors as independent variables, and constructed a multiple logistic regression of farmland spatial distribution probability by random sampling. Then, by using GIS technology and integrating the 2000 data, this study predicted the farmland spatial pattern. When the predicted map was compared with the actual farmland map for 2000, we noted that 71% of the simulation is in accordance with the 2000 farmland pattern. The result satisfactorily proves the reasonability and applicability of our model.     

水中色度测定的研究

针对目视比色法色度测定不足之处,利用分光光度法进行改进.(1)在天然水的测定中,研究了以往的380nm作最大吸收波长测吸光度方法的问题.寻找到最佳波长455nm,吸收池5cm测定天然水吸光度A.(2)在5～400℃测定温度对吸光度无影响,溶液浊度、pH值对吸光度测定的影响呈线性关系.(3)在工业废水的测定中,先扫描出其最大吸收波长,以仪器检测限吸光度0.010为稀释终点.改进废水稀释倍数法.     

生化需氧量测定的方法改进

生化需氧量测定中接种液的制备和稀释倍数的确定是2个关键的步骤,本文提出一种可行的制备接种液的方法,根据实践经验,总结出一种稀释倍数计算方法,适合在实际分析中使用。     

洪水冲刷和地震联合作用下砌体结构的失效风险评估∗

基于风险理论,提出一种用概率方法来考虑洪水和地震作用下砌体结构的失效风险评估方法。根据村镇建筑结构在灾害作用下的性能要求,量化结构的性能指标,分析村镇建筑结构在洪水冲刷和地震联合作用下的易损性,综合考虑洪水冲刷、地震的灾害危险性和结构易损性,通过易损性函数与联合灾害概率密度函数在灾害域上积分,获得结构在不同破坏状态下的超越概率,引入损失比和结构累计失效概率,进而获得全性能状态下的可靠度指标,并与目标可靠度指标对比,进行结构性能评估。算例展示了本文方法的建立过程,结果表明：冲刷对结构轻微破坏和中度破坏的易损性影响较小,对严重破坏和倒塌状态的易损性影响较大;洪水冲刷对结构抗震性能具有较大的影响,相比于仅考虑地震作用下,同时考虑洪水冲刷和地震联合作用时,结构各种破坏状态下的失效概率均有所增加,且随着破坏程度的加剧,冲刷对结构失效概率的影响越来越大。