长江口沿岸碎波带刀鲚仔稚鱼摄食习性与浮游动物分布的相关性研究

为探明长江口沿岸碎波带浮游动物的分布与刀鲚仔稚鱼摄食的关系,2006年7~12月每月大潮期间在长江口沿岸碎波带设置13个站位点,用浮游Ⅰ型生物网(口径30 cm,网目0.2 mm)在表层拖曳采集浮游动物78次,采集到浮游动物72种,平均密度 3 278.95 个/网;用小型拖网(1 m×4 m,网目1 mm)拖曳234次,采集到刀鲚仔稚鱼 37 170 尾,平均密度158.85尾/网。通过胃含物分析共鉴定刀鲚仔稚鱼饵料生物15种(类)(浮游动物11种,浮游幼体4类),平均摄食密度1.306个/尾。研究结果表明:前弯曲期仔鱼偏好摄食哲水蚤、剑水蚤和枝角类;弯曲期仔鱼偏好摄食猛水蚤和桡足类桡足幼体;后弯曲期仔鱼除偏好摄食桡足类幼体以外,也偏好摄食游泳能力较强的糠虾;稚鱼对糠虾有极强的偏好。水温和盐度对刀鲚仔稚鱼的摄食量影响较小;浮游动物分布并不直接影响刀鲚仔稚鱼分布,相关性较小。     

天津市采暖季不同气团来向PM2.5中重金属污染特征及健康风险评价

为了解天津市采暖季PM_2.5中重金属的污染特征及健康风险,使用Xact-625重金属在线分析仪于2020年11月至2021年3月对PM_2.5中的重金属元素进行连续采样,分析10种重金属元素(Pb、 Cd、 Cr、 As、 Zn、 Mn、 Co、 Ni、 Cu和V)的污染特征,利用HYSPLIT模型分析重金属元素的时空分布特征,并结合美国EPA健康风险评价模型对重金属健康风险展开研究.结果表明,采样期间天津市10种重金属元素的总浓度平均值为(261.56±241.74)ng·m^-3,Cr[折算Cr(Ⅵ)]和As元素高于《环境空气质量标准》(GB 3095-2012)的年平均限值.后向轨迹分析表明,天津市主要受到来自西北部中距离气团(1号)、西北部长距离气团(2号)、西南部气团(3号)和东北部气团(4号)的影响.不同气团来向重金属元素呈现不同的污染特征和健康风险,3号气团PM_2.5浓度、10种重金属元素总浓度和5种重金属元素经呼吸途径暴露的终身致癌风险值之和均最高,2号气团10种重金属元素经呼吸途径暴露...     

硫酸盐还原菌对碱性和酸性农田土壤中重金属的钝化效果及其作用机制

通过土壤培养实验考察了硫酸盐还原菌（SRB）包括希瓦氏菌、梭状芽胞杆菌和两者混合菌对碱性和酸性农田土中有效态重金属（Cd、Pb、Cu和Zn）的钝化效果及其作用机制.结果表明,在相同接菌量下,希瓦氏菌处理组对碱性土中有效态重金属的钝化效果优于梭状芽胞杆菌和两者混合菌的处理组;而不同种类的SRB对酸性土中有效态重金属的钝化效果无显著差异.培养第20 d后土壤中有效态重金属的钝化率不再显著变化.SRB处理对碱性土中有效态重金属的钝化率可达80%以上,而对酸性土中有效态重金属的钝化率低于40%.在碱性土中,SRB能够有效还原SO₄^2-,并且提高土壤pH值,使S^2-可与重金属紧密结合,显著提高有效态重金属钝化率.尽管SRB使酸性土壤pH值升高,但土壤仍然呈酸性使SO₄^2-还原受到抑制,不利于有效态重金属的钝化.总体来看,SRB适用于碱性和酸性土壤的重金属污染治理,但与酸性土壤相比,SRB对碱性土壤中有效态重金属的钝化效果更好.     

汶川地震映秀镇地质条件与地表破裂特征调查

2008年5月12日14时28分04秒,四川省汶川县发生了MS 8.0地震.根据地震部门测定,本次地震是从映秀开始破裂,震中位于四川汶川县映秀镇附近(北纬31.015°,东经103.365°).在中国地震局组织的汶川地震科学考察成果基础上,本文分析了映秀地质条件:主要发育的地层为二叠系的石英闪长岩,震旦系的砂岩;通过研究区的主要构造为龙门山中央断裂-映秀-北川断裂;主要的地貌类型为河流地貌.调查了研究区的地表破裂特征,根据研究区的地貌类型将其划分为A、B、C三段,A段为河床沉积地貌,垂直断距最大;B段为丘陵地貌,断距中等,但诱发崩塌地质灾害;C段为河流边滩地貌,断距较小,但震害严重.     

Climate change mitigation policy paradigms—national objectives and alignments

The aim of this paper is to assess how policy goals in relation to the promotion of green growth, energy security, pollution control and greenhouse gas (GHG) emissions reductions have been aligned in policies that have been implemented in selected countries during the last decades as a basis for discussing how a multi objective policy paradigm can contribute to future climate change mitigation. The paper includes country case studies from Brazil, Canada, China, the European Union (EU), India, Japan, Mexico, Nigeria, South Africa, South Korea and the United States covering renewable energy options, industry, transportation, the residential sector and cross-sectoral policies. These countries and regions together contribute more than two thirds of global GHG emissions. The paper finds that policies that are nationally driven and that have multiple objectives, including climate-change mitigation, have been widely applied for decades in both developing countries and industrialised countries. Many of these policies have a long history, and adjustments have taken place based on experience and cost effectiveness concerns. Various energy and climate-change policy goals have worked together in these countries, and in practice a mix of policies reflecting specific priorities and contexts have been pursued. In this way, climate-change mitigation has been aligned with other policy objectives and integrated into broader policy packages, though in many cases specific attention has not been given to the achievement of large GHG emission reductions. Based on these experiences with policy implementation, the paper highlights a number of key coordination and design issues that are pertinent to the successful joint implementation of several energy and climate-change policy goals.     

Bioanalytical and instrumental analysis of estrogenic activities in drinking water sources from Yangtze River Delta

The estrogenic activities of source water from Yangtze River, Huaihe River, Taihu Lake and groundwater in Yangtze River Delta in the dry and wet season were determined by use of reporter gene assays based on African green monkey kidney (CV-1) cell lines. Higher estrogenic activities were observed in the dry season, and the estrogenic potentials in water samples from Taihu Lake were greater than other river basins. None of the samples from groundwater showed estrogen receptor (ER) agonist activity. The 17β-Estradiol (E2) equivalents (EEQs) of water samples in the dry season ranged from 9.41 × 10^?1 to 1.20 × 10¹ ng E2 L^?1. In the wet season, EEQs of all the water samples were below the detection limit as 9.00 × 10^?1 ng E2 L^?1 except for one sample from Huaihe River. The highest contribution of E2 was detected in Yangtze River as 99% of estrogenic activity. Nonylphenol (NP, 100% detection rate) and octylphenol (OP, 100% detection rate) might also be responsible for the estrogenic activities in water sources. Potential health risk induced by the estrogenic chemicals in source water may be posed to the residents through water drinking.     

氯菊酯的酶促降解

从降解氯菊酯的分离株ＹＦ１１提取降解酶并测定了对氯菊酯的降解特性，降解酶在３２．５℃，ｐＨ９．０时对氯菊酯显示最大的降解活性，其每毫克蛋白质最大降解速率为２０．８ｎｍｏｌ／ｍｉｎ，米氏常数为５．２ｎｍｏｌ／ｍＬ。