灰色关联法在铁路环境影响评价中的应用

铁路建设项目对环境的影响具有多层次、多目标、复杂性等特征,因此可以将铁路建设项目对环境的影响分为生态环境、自然环境(环境空气、声环境、水环境) 和社会环境.选取铁路沿线地区具有一定代表性的指标作为评价参数,建立铁路建设项目环境影响指标体系,并通过层次分析方法对各层指标的权重进行计算,然后通过灰色系统理论建立了灰色关联分析模型.模型主要是通过选取相对最优方案,然后利用灰色关联系数计算各个方案与相对最优方案之间的关联程度,通过灰色关联系数对备选方案进行排序,以确定最优方案.最后通过案例对模型进行了验证.     

区域减灾能力信任与公众水灾风险认知——基于社会调查及分析

探索公众的自然灾害认知,有助于揭示风险潜在因素,为开展有效的风险沟通和风险管理提供基础依据.依据在重庆、湖南等部分省市的洪灾易发区开展社会调查收回的635份有效问卷,通过统计分析公众对于区域社会减灾能力的信任及其水灾认知,并探讨了信任对认知的影响.结果表明,公众对于社会减灾能力持信任态度,信任高低依次为:监测预警预报＞基础设施＞防洪工程＞政府应急管理,且信任的高低受年龄、灾害经历和区域经济发展水平的影响而存在差异.减灾能力信任会影响到公众的灾害风险认知,信任的增强会降低公众对洪灾的恐惧心理和对风险大小的判断,同时产生积极和消极并存的防灾行为倾向.因此构建"文化自觉"的科学防灾文化观有利于正确指引公众认识到减灾措施及能力的限度.     

安徽省农村民居地震安全问题调查研究

通过对安徽省农村民居现状进行的调查,阐述了全省农村民居地震安全的基本情况,对调查结果进行了深入分析,得出了开展安徽省农村民居抗震设防工作中存在的主要问题.     

二氯苯在盐水溶液中活度系数的研究

本文采用紫外分光光度法测定了２５．００±０．００１℃下间位和对位二氯苯在ＨＣＯＯＮａ，ＣＨ３ｃＯＯＮａ，（ＮＨ４）２ＳＯ４，ＭｇＳＯ４和Ｎａ２ＳＯ４水溶液中活度系数（ｆ），它们的ｌｇｆ－Ｃ关系符合Ｓｅｔｓｃｈｎｏｗ盐效应公式。     

地面封闭对域市水环境的危害

针对全球出现的城市水环境问题，本文提出了地面封闭的概念，阐述了地面封闭的危害，认为地面封闭减少和阻止了大气降水对地表水和地下水的补给，破坏了区域性的水循环，是形成一些城市水环境问题的重要原因之一。认识地面封闭的危害，对解决这些城市水环境问题将具有巨大的社会经济和生态意义。     

安徽沿江地带投资环境综合研究

改善投资环境吸引外资是经济发展的重要内容。安徽沿江地带是长江经济带重要的组成部分，对安徽沿江地带投资环境进行了分析与评价，并就进一步完善沿江地带宏观投资环境，推动经济联合发展提出了建议与措施。     

黄山贫困山区资源特点与治贫开发对策

黄山是我国十大风景名胜区之一，但全区经济发展水平十分落后，属安徽省贫困地区之一。本文对黄山贫困山区的资源特点与存在问题进行了综合分析，指出了本区贫困落后的主要原因，并就治贫开发提出了相应对策。     

Removal efficiency of a constructed wetland for wastewater treatment according to vegetation dominance

A free water surface wetland was built to treat wastewater containing metals (Cr, Ni and Zn) and nutrients from a tool factory in Santo Tomé, Santa Fe, Argentina. Eichhornia crassipes became dominant and covered about 80% of the surface throughout the first year, and decreased progressively until its disappearance. When water depth was lowered Typha domingensis steadily increased plant cover and attained 30% of the surface by the end of the study. While E. crassipes was dominant, the wetland retained 62% of the incoming Cr and 48% of the Ni. NO3- and NO2-, were also removed (65% and 78%, respectively), while dissolved inorganic phosphate (i-P(diss)) and NH4+ were not removed. Zn was below 50 microg l(-1) in both the influent and effluent. Metal concentration in the sediments did not increase and retention was mediated through macrophytes uptake. During the period of E. crassipes decline the wetland retained 49% of the incoming Cr, 45% of Ni, 58% NO3-, 94% NO2-, 58% NH4+ and 47% i-P(diss). Cr, Ni and Zn in the bottom sediment increased in the inlet but not in the outlet. Since T. domingensis became dominant, retention was 58% Cr, 48% Ni and 64% i-P(diss), while 79% NO3-, 84% NO2- and 13% NH4+ were removed. Metals in the bottom sediment increased in the inlet. In spite of the significant growth of E. crassipes at the beginning, T. domingensis remained after most of the transplanted macrophytes had disappeared. Macrophyte disappearance could be related to the overall toxicity of several environmental constrains as high pH and conductivity, metal concentration, and sulphide presence.     

微生物对煤矿固体废弃物的脱硫效应

煤矸石是煤矿特有的一种固体废弃物，应用本实验室筛选出的氧化亚铁硫杆菌Thiobacillus ferrooxidans和嗜酸氧化硫硫杆菌Thiobacillus thiooxidans对宁夏大武口高硫煤矸石进行微生物脱硫技术及应用条件的研究，如不同煤矸石粒径、不同接种浓度和不同煤矸石浓度。2种脱硫细菌对煤矸石的脱硫效果显著，小粒径煤矸石的微生物脱硫效果更好。考虑脱硫成本及脱硫效率，Thiobacillus ferrooxidans菌最佳的接种浓度为25%，在Thiobacillus Thiobacillus thiooxidans菌悬液中，能脱出最大量硫酸根的煤矸石最佳比例是10%。2种菌混合较单菌株脱硫效果更好，以Thiobacillus ferrooxidans∶Thiobacillus thiooxidans=2∶3的比例混合后对煤矸石的脱硫效果最佳，该结果为煤矿废弃物煤矸石的污染防治提供技术依据。     

Mechanisms and evidence of vertical transmission of infections in pregnancy including SARS-CoV-2s

There remain unanswered questions concerning mother-to-child-transmission of SARS-CoV-2. Despite reports of neonatal COVID-19, SARS-CoV-2 has not been consistently isolated in perinatal samples, thus definitive proof of transplacental infection is still lacking. To address these questions, we assessed investigative tools used to confirm maternal-fetal infection and known protective mechanisms of the placental barrier that prevent transplacental pathogen migration. Forty studies of COVID-19 pregnancies reviewed suggest a lack of consensus on diagnostic strategy for congenital infection. Although real-time polymerase chain reaction of neonatal swabs was universally performed, a wide range of clinical samples was screened including vaginal secretions (22.5%), amniotic fluid (35%), breast milk (22.5%) and umbilical cord blood. Neonatal COVID-19 was reported in eight studies, two of which were based on the detection of SARS-CoV-2 IgM in neonatal blood. Histological examination demonstrated sparse viral particles, vascular malperfusion and inflammation in the placenta from pregnant women with COVID-19. The paucity of placental co-expression of ACE-2 and TMPRSS2, two receptors involved in cytoplasmic entry of SARS-CoV-2, may explain its relative insensitivity to transplacental infection. Viral interactions may utilise membrane receptors other than ACE-2 thus, tissue susceptibility may be broader than currently known. Further spatial-temporal studies are needed to determine the true potential for transplacental migration.