亚硝态氮和氨态氮急性胁迫下曼氏无针乌贼幼体血液的生化指标

将曼氏无针乌贼幼体置于24 h半致死剂量的亚硝态氮和氨态氮溶液中(10 mg·L-1 NaNO2和300 mg·L-1 NH4Cl),检测6、12和24 h各点及对照组曼氏无针乌贼幼体血液生化指标的变化.结果表明,随着处理时间的延长,NaNO2处理组血细胞密度(THC)(p＜0.05)、甘油三酯(TG)(p＜0.05)...     

Occurrence, distribution, and source of polybrominated diphenyl ethers in soil and leaves from Shenzhen Special Economic Zone, China

Polybrominated diphenyl ethers (PBDEs) were measured in soil and three plant species samples taken at different land use areas in Shenzhen China. The concentrations of ??₇BDEs (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, and BDE-183) and BDE-209 in the surface soils ranged from 0.23 to 271 and 8.9 to 5,956 ng/g dry weight (dw), respectively. These figures are comparable to that in the soils of electronic waste dismantling sites. BDE-209 was the predominant congener (contributes 85?C99% of ??₈PBDEs (??₇PBDEs plus BDE-209)) in soils. The regression slopes of total organic carbon and individual BDE congeners were rather gentle, indicating that factors other than soil organic matter regulated the soil concentrations. Proximity to sources of deposition processes might be the major factors. In the plant leaves, ??₇BDEs and BDE-209 concentrations ranged from 1.29 to 5.91 and 5.49 to 28.2 ng/g dw, respectively. BDE-209 is also the dominant component, but the contribution was much lower compared with that in soils. Bauhinia purpurea Linn. and Michelia alba DC. show some similarities on the uptake of PBDEs, while Ficus microcarpa var. pusillifolia is different from them. The correlations between plant leaf concentrations and predicted gaseous concentrations were moderate, indicating that gaseous concentration did not influence the leaf concentration significantly.     

Degradation of dye rhodamine B under visible irradiation with Prussian blue as a photo-Fenton reagent

Rhodamine B can be degraded using Prussian blue as a photo-Fenton like reagent under λ > 420 nm visible irradiation. Kinetic studies show ln(C _o/C _t ) is linearly proportional to the reaction time during the photo-degradation process; thus, the degradation reaction obeys a pseudo-first order kinetic law. It is very interesting that the presence of salinity such as 0.1 M KCl can speed up greatly the degradation rate: the time to achieve 90.0% degradation ratio is shortened from 120.0 to 40.0 min under comparable conditions, which is very useful in the treatment of wastewaters with high content of salinity.     

试述实习生的工伤事故认定及赔付

从1951年原政务院颁布《中华人民共和国劳动保险条例》始,我国的工伤保险制度几经变革与发展,然而日趋完善的背后依旧存在着诸多问题,2009年7月24日国务院法制办发布了关于修改《工伤保险     

地表水特定项目优化检测技术研究

对地表水中特定项目指标的检测技术进行了优化研究,根据检测目标化合物的结构性质和色谱分析手段的兼容性,对前处理方法和分析手段进行了优化整合,提出了特定项目的解决方案,提高了工作效率,对切实保障饮用水源安全有实际意义.     

广元市次生地质灾害分布特征及影响因素分析——以朝天区为例

四川省广元市朝天区是汶川8.0级地震的重灾区之一,由地震触发的崩塌、滑坡等次生地质灾害对人民群众生命财产安全构成巨大威胁。基于实地调查,对震后地质灾害隐患点进行了统计分析,指出了地震地质灾害的分布特征,并对其影响因素进行了深入分析。区内地震地质灾害点多分布在海拔800 m以上的陡坡或陡崖部位,并沿龙门山断裂带、嘉陵江水系及交通路线呈线状或带状分布。地震地质灾害的发生是内外力共同作用结果,其中地震力和断裂构造带对地质灾害发生起着决定性的作用,而地层岩性对灾种起关键性的作用,滑坡多发育在页岩、片岩、板岩、千枚岩等软岩分布区,崩塌多发育在灰岩、砂岩等硬岩分布区。     

西南高山峡谷区植被变化及影响因素分析

西南高山峡谷区是我国典型生态脆弱区,认识其植被变化特征及影响因素可以为西南高山峡谷区生态环境建设对策的制定提供理论依据,对实现区域经济、环境以及生态和谐统一发展,具有一定的现实意义.基于2000~2019年NDVI、社会经济因子和自然因子数据集,采用一元线性回归法、Hurst指数、地理探测器模型和变异系数等方法分析了西南高山峡谷区NDVI时空变化及稳定性特征,并探讨了NDVI空间分异影响因素.结果表明：①空间上看,植被呈现东南高,西北低的分布格局,中高和高植被覆盖的区域面积占比71.71%,植被覆盖总体处于较高水平.时间上看,植被呈现改善趋势的区域面积占比85.90%,恢复效果明显,且未来植被变化趋势还将以改善为主.②高程、植被类型和土壤类型是影响NDVI空间分异的主导因子,q值均不低于0.40;气温和降雨量为次要因子,q值分别为0.274和0.225.双因子交互作用增强了单因子的影响力,表现为双因子增强和非线性增强两种关系,其中高程∩植被类型组合q值最高为0.714,其次是高程∩土壤类型组合q值为0.688.③研究时段内NDVI整体稳定性较好,低波动变化和较低波动变化的区域面积占比为89.95%;而中等以上波动的区域面积占比为10.05%,集中在海拔高、气温低、降雨少、土壤贫瘠和植被较差等生态环境相对脆弱的区域.植被变化是多因素综合作用的结果,需因地制宜,有针对性地采取不同策略修复西南高山峡谷区生态环境.     

VOC emission caps constrained by air quality targets based on response surface model: A case study in the Pearl River Delta Region, China

Because of the recent growth in ground-level ozone and increased emission of volatile organic compounds (VOCs), VOC emission control has become a major concern in China. In response, emission caps to control VOC have been stipulated in recent policies, but few of them were constrained by the co-control target of PM_2.5 and ozone, and discussed the factor that influence the emission cap formulation. Herein, we proposed a framework for quantification of VOC emission caps constrained by targets for PM_2.5 and ozone via a new response surface modeling (RSM) technique, achieving 50% computational cost savings of the quantification. In the Pearl River Delta (PRD) region, the VOC emission caps constrained by air quality targets varied greatly with the NO_x emission reduction level. If control measures in the surrounding areas of the PRD region were not considered, there could be two feasible strategies for VOC emission caps to meet air quality targets (160 µg/m³ for the maximum 8-hr-average 90th-percentile (MDA8-90%) ozone and 25 µg/m³ for the annual average of PM_2.5): a moderate VOC emission cap with <20% NOx emission reductions or a notable VOC emission cap with >60% NO_x emission reductions. If the ozone concentration target were reduced to 155 µg/m³, deep NO_x emission reductions is the only feasible ozone control measure in PRD. Optimization of seasonal VOC emission caps based on the Monte Carlo simulation could allow us to gain higher ozone benefits or greater VOC emission reductions. If VOC emissions were further reduced in autumn, MDA8-90% ozone could be lowered by 0.3-1.5 µg/m³, equaling the ozone benefits of 10% VOC emission reduction measures. The method for VOC emission cap quantification and optimization proposed in this study could provide scientific guidance for coordinated control of regional PM_2.5 and O₃ pollution in China.     

基于在线观测的太原市冬季PM2.5中金属元素污染水平及来源解析

为更好地识别太原市PM_2.5的来源,于2022年1月采用在线多金属监测仪对太原市区PM_2.5中13种金属元素(K、Ca、Ba、Cr、Mn、Fe、Cu、Ni、Zn、As、Se、Pb和Sr)小时浓度进行了监测,分析了其污染特征,采用正定矩阵因子分解(PMF)模型解析了其来源.结果表明,13种金属元素浓度之和均值为(3 901.6±2 611.2)ng·m^-3,在PM_2.5中平均占比为(7.1±7.7)%.Fe、Ca和K是3种主要的金属元素,浓度平均值分别为(1 319.5±1 003.5)、(1 181.0±1 241.6)和(883.3±357.3)ng·m^-3.ρ[Cr(Ⅵ)](4.6ng·m^-3)和ρ(As)(11.2 ng·m^-3)平均值高于国家环境空气质量(GB 3095-2012)和世界卫生组织的标准值.PMF源解析结果显示：扬尘、机动车排放、不锈钢制造、生物质燃烧与垃圾焚烧、散煤燃烧和工业燃煤是PM_2.5     

粤港澳大湾区污染场地土壤风险管控制度体系建设与思考

防范污染场地环境风险和保障人居环境安全是粤港澳大湾区建设世界级城市群面临的重要挑战和工作内容之一.由于粤港澳在政治制度和土地管理等方面的差异,以及珠三角9市内部城市化水平、产业结构以及环境管理能力的差别,大湾区各地污染场地风险管控模式有明显的差异,分析粤港澳大湾区典型城市污染场地风险管控特点,对加强污染场地风险管控技术交流与合作,优化大湾区污染场地风险管控制度具有重要意义.本文在简述我国污染场地风险管控制度体系的基础上,重点介绍了广州、深圳、东莞、香港和澳门的污染场地风险管控制度体系、监管对象、污染评估与整治程序等的特点,对其风险管控制度体系进行了分析与对比,并针对土地规划、政策反馈、信息公开及联盟机制探索等提出了思考与建议.总体来看,香港及珠三角部分地市构建了行之有效的污染场地风险管控制度体系,且体现了一定的地方特点,但随着污染场地的进一步开发再利用,打造粤港澳大湾区世界级城市群的建设目标将对污染场地风险管控策略的安全性、精细化和时效性等提出更高的要求,互相借鉴和充分学习,加强大湾区2区9市污染场地风险管控上的技术交流与合作,是实现大湾区污染场地安全再利用与高效开发的有效路径.