TEV、UT、UHF技术在开关柜局部放电检测中的应用

针对10kV开关柜局部放电问题,为排除干扰,准确判断开关柜局部放电类型和放电点位置,提出采用暂态地电位(transient earth voltage, TEV)、超声波(ultrasonic test, UT)、特高频(ultra high frequency, UHF)技术进行联合检测的方法,并在现场实测工作中进行了应用和验证。结果表明:该联合方法对开关柜设备缺陷的检测与定位非常有效,提高了开关柜局部放电检测的准确性和有效性。     

基于GIS的鄱阳湖流域非点源吸附态污染物时空变化研究

鄱阳湖作为中国最大的淡水湖,国际重要湿地,其生态环境保护与可持续发展意义重大。基于GIS技术,以鄱阳湖流域为研究区域,利用3个时期多源数据,首先运用土壤流失方程估算鄱阳湖流域土壤侵蚀量,计算土壤侵蚀模数,然后根据泥沙输移比估算水体的泥沙负荷,最后采用颗粒态氮磷营养盐迁移经验模型定量研究鄱阳湖流域非点源吸附态污染物N、P负荷的时空变化规律。结果显示:吸附态氮磷污染负荷在空间分布上呈现出四周高、中间低的特点,相对较高的区域位于流域中、上游,这主要由于该区域多为山地陡坡;相对略低的区域位于流域的下游地区,这主要因为该区域平原和丘陵交错分布,土壤侵蚀强度较低。时间变化上,全流域单位面积N、P吸附态污染物负荷大都呈现先增加后减少的趋势,同时减少的幅度较增加的幅度大。     

离子液体萃取法回收废水中的醋酸丁酯

利用离子液体1-己基-3-甲基咪唑六氟磷酸盐萃取模拟废水中的醋酸丁酯。萃取液经减压蒸馏回收醋酸丁酯，离子液体也得到再生。实验结果表明:萃取率随废水与离子液体体积之比(相比)的增加而减小，随萃取时间的延长而增大，随萃取温度的升高而增大;在相比为6∶1、萃取时间为40min、萃取温度为50℃的条件下，萃取率达98.98%，醋酸丁酯纯度达99.8%;回收后离子液体可重复使用且萃取率基本不变。     

Residents’ concerns and attitudes toward a municipal solid waste landfill: integrating a questionnaire survey and GIS techniques

The ever-growing industry of municipal solid waste (MSW) disposal appeals to the growing need for disposal facilities, and MSW treatment facilities are increasingly an environmental and public health concern. Residents living near MSW management facilities are confronted with various risk perceptions, especially odour. In this study, in an effort to assist responsible decision-makers in better planning and managing such a project, a structured questionnaire was designed and distributed to assess the nearby residents’ concerns and attitudes surrounding the Laogang Landfill in Shanghai. Geographic information system techniques and relevance analysis were employed to conduct the spatial analysis of physical perceptions, especially odour annoyance. The findings of the research indicate that a significant percentage of the responding sample was aware of the negative impacts of landfills on the environment and public health, and residents in close proximity preferred to live farther from the landfill. The results from the spatial analysis demonstrated a definite degree of correlation between odour annoyance and distance to the facility and proved that the benefits of the socially disadvantaged have been neglected. The research findings also direct attention to the important role of public participation, information disclosure, transparency in management, and mutual communication to avoid conflicts and build social trust.     

医疗废物高温蒸气杀菌工艺中质热传递模型

医疗废物高温蒸气灭菌工艺中，如何使蒸气充分渗透到医疗废物内部是决定杀菌效果的关键。结合实际的操作工艺，以单片物料作为研究对象，将其视为多孔介质，从多孔物料传质传热的基本理论出发，建立了医疗废物内部传质传热数学模型，给出了其解析解，并通过实验验证了所建模型的合理性。     

浅谈小型水电站建设工程中的安全管理

由于小水电站建设工程相对于大中型水电工程规模小、地处偏远山区、信息滞后以及对小型水电站建设工程安全问题认识不足等原因,有的安全措施得不到很好落实,不安全事件或事故时有发生。加强小水电站建设工程安全管理,认真落实国家有关安全法规、条例和规章制度,防止不安全事件的发生,在保证安全的前提下,又快又好又省地完成水电站建设工程项目,尤为重要。     

Persistent organic pollutants in food items collected in Hong Kong

This study aims to investigate levels of POPs in meat, edible oils, nuts, milk and wine collected from Hong Kong. Naphthalene, pp-DDE, beta-, gamma-HCH and PBDE 47 were detected in most of the food items. Goose liver accumulated the highest PAHs (47.9 ng g⁻¹ wet wt), DDTs (25.6), HCHs (13.0), PCBs (4.17), PBDEs (468 pg g⁻¹ wet wt) among all the selected food. Meat and nut groups had significant (p < 0.01 or 0.05) correlations between lipid contents and concentrations of PAHs (meat: r = 0.878), HCHs (meat: r = 0.753), DDTs (meat: r = 0.937; nuts: r = 0.968) and PCBs (meat: r = 0.832; nut: r = 0.946). The concentrations of DDTs, HCHs and PCBs in vegetable oil were lower, but HCHs in fish oil were higher, when compared with other countries. The concentrations of PAHs, DDTs, PCBs and PBDEs in food tested in the present study were all below various safety guidelines.     

Microbial degradation of dissolved organic matter (DOM) and its influence on phenanthrene-DOM interactions

Microbial degradation-induced changes in the characteristics of dissolved organic matter (DOM), and the subsequent effects on phenanthrene-DOM interactions were investigated based on the microbial incubation of DOM collected from four different sources for 28 d. Partially biodegraded DOM presented higher specific UV absorbance (SUVA), lower protein-like fluorescence, higher humic-like fluorescence, lower aliphatic carbon fraction, and higher hydrophobic neutral fractions compared to the original DOM. Microbial changes in DOM led to an increase in the isotherm nonlinearity as well as the extent of phenanthrene binding. A negative relationship between SUVA and the Freundlich n values was established for the original and the biodegraded DOM, suggesting that aromatic condensed structures may play important roles in providing nonlinear strong binding sites irrespective of microbial degradation. In contrast, there were two separate slopes of the correlations between the percentage of hydrophobic acid (HoA) fraction and the n values for the original and the biodegraded DOM with a higher slope exhibited for the latter, implying that the microbial utilization of oxygen-containing structures in the HoA fractions may contribute to enhancing the associated isotherm nonlinearity.     

长江流域年平均气温的时空变化特征

利用长江流域146个气象站点1960~2005年的逐年气温资料，选用EOF和REOF方法识别长江流域年平均气温空间变化特征，并对长江流域年平均气温变化敏感区域进行时间演变分析和突变检测。研究表明:长江流域年平均气温主要有2种空间振荡型（即全流域气温变化趋向一致型和流域内气温变化存在东西向差异型），3个变化敏感区域（长江流域中下游地区、长江流域南部和金沙江流域）。3个变化敏感区域的年平均气温都在20世纪90年代明显升高，且均在90年代后期呈突变增加，其中金沙江流域升温趋势最为明显，气候倾向率为0.20℃/10a。全流域1991~2005年年平均气温距平空间分布表明，自1991年以来全流域都为升温趋势，其中长江流域中下游地区和金沙江流域是升温幅度最大的地区。