污染源普查数据质量评估方法研究

结合第一次全国污染源普查工作实际,给出普查数据质量评估指标,提出污染源普查数据质量评估内容。在此基础上,研究普查数据质量检验评估方法,确立普查数据质量评估体系,为计算机辅助污染源普查质量评估建立理论基础。     

Partitioning of dioxin and dibenzofuran congeners between plasma and cell fractions of blood from 10 adult male patients

We previously characterized levels of dioxin and dibenzofuran congeners in adipose tissue and plasma fraction of blood collected from 20 adult males, using paired speciments. It has been found that the 2,3,7,8-TCDD level reported on a lipid basis was similar, although not identical, in plasma lipid and in adipose tissue lipid from the same patients, however, higher levels of the more chlorinated dioxins and dibenzofurans existed in plasma lipid as compared to adipose tissue lipid. This study reports measurements from ten individuals' blood cell fraction and compares this to the plasms fraction and to adipose tissue lipid. In all cases where readily detectable amounts of PCDD/Fs were found, a minimum of 85% was in the plasma fraction and less than 15% in the cellular component. Congeners varied in percentage for each component.     

Suitability of process-based tree growth models for addressing tree response to climate change

Empirical models of tree growth have been used for many years to predict timber yields and other properties of trees. However, such models rely on measured relationships between tree growth and historic environmental conditions. As anthropogenic actions alter the environment, especially atmospheric composition, empirical models become less reliable and process-based models become more useful. Process-based models are challenged to simulate growth of structurally and physiologically complex organisms using explicit mathematical expressions to capture growth response to environmental conditions. In this review we summarize the physiological requirements of process-based models and examine the capabilities of six published models (CARBON, ECOPHYS, PGSM, TREE-BGC, TREGRO, W91) for simulating tree response to changes in environmental conditions (elevated temperature, increased CO(2) concentration, and enhanced concentrations of tropospheric ozone). These analyses indicate that current models are reliable integrators of environmental effects on individual processes (e.g. photosynthesis), but may be less reliable where physiological acclimation occurs or when extrapolated to growth of specific tree compartments.     

CeO_2/Fe_2O_3对高浓度苯酚废水微波诱导的氧化催化

对高浓度苯酚废水提出了用复合催化剂CeO2/Fe2O3进行微波诱导催化氧化的降解方法,并与单一催化剂Fe2O3的催化氧化效果进行了比较,对两者的表观反应动力学进行了分析,结果表明复合催化剂的催化效果比单一催化剂的催化效果高15%以上,其主要原因是CeO2/Fe2O3复合物具有很强的催化能力和较高的干电流变活性,有利于电子的迁移和羟基自由基·OH的形成,从而有利于苯酚的氧化降解。     

德尔菲法在归纳主要环境问题中的应用

尝试用德尔菲法归纳建德市的主要环境问题,对15位专家的2轮咨询结果进行统计分析,筛选出15个指标组合成10个主要环境问题,较好地反映了建德市的环境污染现状和变化趋势。     

Chlorinated dibenzo-p-dioxin and dibenzofuran levels in human adipose tissue and milk samples from the north and south of Vietnam

Although 2,3,7,8-TCDD has been found to be extremely toxic to a variety of laboratory aminals, human epidemiology studies, where exposure to 2,3,7,8-TCDD has been less well characterized than in animal toxicologic studies, have been less conclusive in characterizing the extent of toxicity. In order to determine whether the newly refined techniques of human adipose tissue biopsy including isomer specific and sensitive measurement of PCDDs and PCDFs might be able to assist in finding populations within the same country with high and low levels of dioxins, adipose tissue samples were taken and levels analyzed from the north and south of Vietnam. It seemed reasonable, based on previous work, that high levels of 2,3,7,8-TCDD might still be found in adipose tissue in selected patients living in areas sprayed with Agent Orange and other 2,3,7,8-TCDD containing herbicides, and that lower levels should be found in patients not exposed to 2,3,7,8-TCDD from herbicides or other sources, such as persons who had always resided in the north of Vietnam. Of 9 specimens from patients hospitalized in Hanoi who had never been south, none had detectable adipose tissue levels of 2,3,7,8-TCDD at a detection limit of 2 or 3 ppt on a wet weight basis. Of 15 specimens from Ho Chi Minh City hospitalized patients the mean of positive specimens (12 of 15) was 28 on a lipid basis. The mean of the positive values from the south is about 2 to 3 times higher than found in the North American Continent control patients where the mean is about 6–10 ppt and much higher than in the north of Vietnam. In the northern specimens, the levels were non-detectable with a sensitivity of between 2 and 3 ppt. Other PCDD and PCDF isomers not found in Agent Orange, the penta- through octachlorinated dibenzo-dioxins and dibenzofurans, were similar in isomer type and quantity in the south of Vietnam to what we previously reported in North America. Adipose tissue from the north of Vietnam contained the lowest levels of four through eight chlorinated dioxins and furans thus far reported. The initial data suggests that populations exist in the south of Vietnam with elevated levels of 2,3,7,8-TCDD at the present time, fourteen years after the last known 2,3,7,8-TCDD (Agent Orange) application, superimposed on a preexisting body burden of dioxins and dibenzofurans from sources other than Agent Orange such as technical grade pentachlorophenol or products of incineration contaminated with higher chlorinated PCDDs or PCDFs. In light of the recent finding that unexpected levels of PCDDs and PCDFs exist in the general adult population of industrialized countries, ca. 1,000 to 1,200 ppt, wet weight of total dioxin and furan isomers in adipose tissues, it seems reasonable that the extent of human toxicity of dioxins may be more readily characterized in Vietnam than in industrialized countries. Because 2,3,7,8-TCDD was applied in 1962–1970, although not yet cleaned up, the levels of 2,3,7,8-TCDD in the environment, the food chain, and in humans, would be expected to decrease with time. Therefore, if studies are not initiated in a timely fashion, the opportunity to better characterize the extent of the toxicity of TCDD to humans as well as the persistence of TCDD in the environment in Vietnam may be lost.     

Climate change and migration in the Pacific: options for Tuvalu and the Marshall Islands

Regional Environmental Change - As climate change impacts, particularly rising sea levels, manifest there is a high probability that some island populations will be faced with the need to relocate....     

外加电流阴极保护用钛阳极

外加电流阴极方法是一种有效的保护金属不被腐蚀的方法,钛阳极是外加电流阴极保护中的重要部件.主要介绍了钛阳极的制备方法,给出了3种不同环境中钛阳极的强化寿命检测方法,对钛阳极和其他辅助阳极的性能进行了比较,钛阳极由于优异的物理、化学及电化学性能,目前已成为最有前途的外加电流阴极保护用辅助阳极材料.