纳污湿地上覆水中重金属的监测及评价

以武河湿地为研究区域采集上覆水水样,采用ICP-AES法测定湿地水体中重金属的含量,参照有关标准用水质标准级别法对水中重金属污染情况进行了评价。结果表明:武河湿地中重金属Hg污染十分严重,各采样点均有分布且水质属劣Ⅴ类。重金属元素Cd污染并不严重,总体水质较好。重金属元素As、Cr、Cu、Pb在武河湿地中污染较轻近乎无污染,水质为Ⅰ类。由于重金属Hg的污染十分严重所以研究区内综合质量等级在4以上,水质为Ⅴ类和劣Ⅴ类,污染严重。     

焙烧炉筒体结构强度有限元分析

对焙烧炉筒体结构进行有限元建模仿真,考虑热应力、压力和重力对筒体结构受力的影响,计算了焙烧炉关键部位的蠕变疲劳寿命,同时探究进气温度、保温层及对流系数等参数的影响。结果表明:热应力是影响结构强度的关键因素;焙烧炉筒体在许用蠕变变形量为5%的情况下,其使用寿命超过设计寿命;在筒体加热过渡段铺设保温层,降低与外界空气对流和提高进气温度,有利于降低筒体应力。     

Hyperautomobility and Governmentality in Auckland

Abstract

A number of cities around the world are associated with very high levels of private motor car usage, and Auckland provides an example of one of these ‘hyperautomobile’ cities. There are many problems with this system of transportation and dependence on the private car, including environmental, social and city design dimensions. Though there is a clear aspiration to move towards reduced levels of car usage in the city's transport and spatial planning strategies, there are major difficulties in implementation terms. We develop and consider future scenarios to 2041 to reduce these levels of motorization, and subsequent transport CO₂ emissions, with a much greater use of public transport, walking and cycling, urban planning, and low emission vehicles. The current implementability of such a ‘sustainable mobility’ future is however questioned in the current political and social context, and critically debated in terms of the available governance mechanisms and the limited attempts to shape the behaviour of the public. We conclude by calling for a reconsideration of the policy measures being considered, including the range and levels of application and investment; with a much wider framing of the transport planning remit, and carried out within a much stronger participatory framework for decision-making.     

Constitutional tolerance to heavy metals of a fiber crop, ramie (Boehmeria nivea), and its potential usage

It is observed that ramie (Boehmeria nivea), an economic fiber crop, can establish and colonize metal-contaminated sites in China. Metal tolerance and accumulation by ramie originating from 13 metal-contaminated and 4 “clean” sites in China were compared under field and hydroponic conditions. All selected populations and germplasms displayed good growth performance under diverse metal-contaminated habitats; while growth responses, metal accumulation and tolerance were similar among the 8 populations and 2 germplasms when exposed to solutions containing elevated As, Cd, Pb, or Zn in the laboratory. These revealed that ramie possesses a certain degree of constitutional metal tolerance. To our knowledge, this is the first report of constitutional metal tolerance possessed by a fiber crop. Ramie can be considered as a good candidate for both fiber production and phytoremediation of sites contaminated by multi-metals, as it accumulates relative low metal concentrations, but possesses both high biomass and high economic value.     

An ‘ameridelphian’ marsupial from the early Eocene of Australia supports a complex model of Southern Hemisphere marsupial biogeography

Recent molecular data strongly support the monophyly of all extant Australian and New Guinean marsupials (Eomarsupialia) to the exclusion of extant South American marsupials. This, together with available geological and fossil evidence, has been used to argue that the presence of marsupials in Australia is simply the result of a single dispersal event from South America during the latest Cretaceous or Palaeocene, without subsequent dispersals between the two continents. Here, I describe an isolated ankle bone (calcaneus) of a metatherian from the early Eocene Tingamarra Local Fauna in northeastern Australia. Strikingly, this specimen, QM F30060, lacks the ‘continuous lower ankle joint pattern’ (CLAJP), presence of which is a highly distinctive apomorphy of the marsupial clade Australidelphia, which includes Eomarsupialia, the living South American microbiotherian Dromiciops and the Tingamarran fossil marsupial Djarthia. Comparisons with a range of marsupials and stem-metatherians strongly suggest that the absence of the CLAJP in QM F30060 is plesiomorphic, and that this specimen represents the first unequivocal non-australidelphian (‘ameridelphian’) metatherian known from Australia. This interpretation is confirmed by phylogenetic analyses that place QM F30060 within (crown-group) Marsupialia, but outside Australidelphia. Based on these results, the distribution of marsupials within Gondwana cannot be explained by simply a single dispersal event from South America and Australia. Either there were multiple dispersals by marsupials (and possibly also stem-metatherians) between South America and Australia, in one or both directions, or, alternatively, there was a broadly similar metatherian fauna stretching across southern South America, Antarctica and Australia during the Late Cretaceous–early Palaeogene.     

制革废水脱硫试验研究

制革废水中含有大量的硫化物，试验研究了催化曝气，混凝沉淀，混凝气浮及生化法等工艺的脱硫效果，并考察了工艺的综合作用。结果表明上述工艺均可全部或近于全部除去废水中的硫化物，并对ＣＯＤ、总Ｃｒ等也有综合的去除功能。     

Interpreting measures of economic loss: Evidence from contingent valuation and experimental studies

From the standpoint of conventional welfare theory, it is surprising that responses to contingent valuation studies of environmental goods have shown a consistent difference between willingness to pay and compensation demanded measures of economic loss. This paper examines these results in light of four reasons most often given as grounds for their dismissal. New experimental evidence supports an interpretation of the observed disparity in payment-and compensation-based measures as both real and psychologically meaningful. An alternative conceptual framework, suggested by prospect theory, is outlined and its relevance for economic assessments of potential environmental change is discussed briefly.     

The influence of obstetricians on the utilization of amniocentesis

A study of 173 Western New York State obstetricians was undertaken to study referral patterns for second-trimester amniocentesis in 1974–1978. Referral patterns were analysed in relation to obstetrician age, religion, board certification, hospital affiliation and practice location. Forty-seven per cent of the obstetricians had never referred a patient for amniocentesis. Those referring were overall younger than those not referring and were significantly more often board certified. Obstetrician religion was significantly related to referral with fewer Catholic obstetricians referring. Hospital affiliation (teaching versus non-teaching) and obstetrician practice location (urban versus rural) were not important factors after controlling for religion and board certification. Obstetrician factors account for a small but important part of the variability in referral, and other factors, such as cost and access to laboratory and obstetric care need further investigation.