Estimation and inter-comparison of dust aerosols based on MODIS, MISR and AERONET retrievals over Asian desert regions

This study presents detailed analysis of spatiotemporal variations and trend of dust optical properties i.e., Aerosol Optical Depth(AOD) and Angstrom component over Asian desert regions using thirteen years of data(i.e., 2001–2013) retrieved from Aerosol Robotic Network(AERONET), Moderate Resolution Imaging Spectroradiometer(MODIS) and Multi-angle Imaging Spectroradiometer(MISR). These regions include Solar Village, Dunhuang and Dalangzadgad and are considered as origin of desert aerosols in Asia. Mann–Kendall trend test was used to show the trend of AOD. The relationship of AOD with weather parameters and general AOD trend over different wavelengths has also been shown. AOD's trend has been observed significant throughout the year in Solar Village, while in Dunhuang and Dalanzadgad the significant trend has been found only in peak period(March–June).Analysis show high values of AOD and low values of angstrom in Solar Village during peak period. In Chinese desert regions, high values of AOD have been found during peak period and low values in pre-peak period. Significant relationship has been observed between AOD and average temperature in Solar Village and Dalanzadgad whereas rainfall and wind speed showed no significant impact on AOD in all desert regions.     

Enzyme-electrolytic degradation of dichloromethane: Efficiency, kinetics and mechanism

Enzymatic electrolysis cell(EEC) has advantages over microbial electrolysis cell(MEC) due to the needless of microbe inoculation and high-efficiency of enzymatic reaction. In this study, an EEC was first applied to achieve the effective degradation of halogenated organic pollutants and dichloromethane(CH_2Cl_2) was utilized as a model pollutant. The results indicate that the degradation efficiency of CH_2Cl_2 after 2 hr reaction in the EEC was almost100%, which was significantly higher than that with enzyme(51.1%) or current(19.0%). The current induced the continuous regeneration of reduced glutathione(GSH), thus CH_2Cl_2 was degraded under the catalysis of GSH-dependent dehalogenase through stepwise dechlorination, and successively formed monochloromethane(CH_3Cl) and methane(CH_4). The kinetic result shows that with a current of 15 mA, the maximum specific degradation rate of CH_2Cl_2(3.77 × 10~(-3) hr~(-1)) was increased by 5.7 times. The optimum condition for CH_2Cl_2 dechlorination was also obtained with pH, current and temperature of 7.0, 15 mA and 35°C,respectively. Importantly, this study helps to understand the behavior of enzymes and the fate of halogenated organic pollutants with EEC, providing a possible treatment technology for halogenated organic pollutants.     

浅海平台油气火灾事故模拟评估应用

全球海洋油气开发重特大火灾事故频发,油气生产安全面临严峻挑战,以我国浅海某中心平台组为研究对象,对可能发生的三相分离器喷射火火灾、管线交叉处喷射火火灾、生产平台池火火灾以及储罐平台池火火灾,采用FDS软件建立该平台组的火灾动力学模型,对油气泄漏后火灾的发展态势、火场温度、热辐射强度、设备温度以及不同火灾工况的对比分析,研究火灾发生后对人员伤害,以及平台上油气管线、分离器、油气储罐、平台栈桥等重要设备安全性的影响,并提出操作人员和重要设备的安全距离。针对火灾事故风险控制提出建议措施,对海上火灾风险分析未来研究方向进行阐述。     

National and Regional-Level Human-Environment (Ecosystems) Interactions: Some Empirical Evidence from China

The state of human-environment (ecosystems) interactions—ecosystems (land cover classes), population, biodiversity hotspots and protected status—is examined in the eastern coastal zones, the eastern region, the middle region, the western region and the whole of China. The analysis is based on consistent, comprehensive, geo-referenced and recent datasets and advanced analytical Remote Sensing and Geographic Information System (GIS) techniques. A comparative national and regional priority ranking of the provinces was conducted using the total score of eight indicators, for the four dimensions of human-environment (ecosystems) interaction. Using, these ranks, all the provinces were grouped in low, high and medium priority provinces. The comparative ranking and categorization of provinces will be useful for designing policies and management operations for spatially-differential scientific planning and management of environment (ecosystems) at the regional and national levels in China.     

内蒙古自治区锡林郭勒盟地震的启示

2004年3月24日9时33分在内蒙古自治区东乌珠穆沁旗与西乌珠穆沁旗间(北纬45.4°,东经118.2°)发生5.9级地震。北京、辽宁朝阳、吉林白城、河北承德地区有感。自治区地震局迅速确定“三要素”,召集紧急会议确定考察队与局留守队,并迅速向灾区了解灾情,向自治区政府报告。同时启动破坏     

成都市可持续发展水平空间分布特征

本文通过对成都市 8县 4市 3区的可持续发展静态指数计算 ,定量地表达了成都市各区县目前可持续发展状况的对比关系 ,分析造成这种格局的原因并提出相应对策     

长江江苏段抗生素的空间分布特征及典型污染来源分析

利用超高效液相色谱-三重四极杆质谱法,于2021年4月对江苏省长江干流12个监控断面、入江支流116个监控断面表层水中7大类42种抗生素的分布特征和浓度水平进行研究,并开展典型污染来源分析。结果表明,平水期长江干流42种抗生素总质量浓度范围为47.3～92.8 ng/L,处于较低水平;各入江支流抗生素总质量浓度范围为16.2～3 052 ng/L,干支流水体中检出品种以磺胺类、氯霉素类、林可酰胺类及大环内酯类为主;通过差异性比较发现,C市存在磺胺类抗生素污染的典型区域;典型污染溯源分析结果表明,工业废水可能是该地区环境水体中抗生素污染的来源之一。长江江苏段及地表水中各类抗生素普遍检出,虽然抗生素总量水平不高,但由制药废水、畜禽养殖、污水处理厂等污染源引入而引起的长期积累仍是隐患。研究结果为江苏省长江流域水环境抗生素污染控制和管理提供基础数据。     

电解浮选用于活性污泥固液分离的研究

在装有Ti/RuO₂-IrO₂-TiO₂阳极、Ti阴极的电解浮选槽中进行了活性污泥固液分离的研究.考察了影响电解浮选性能的操作参数,这些参数包括水力停留时间、电流密度、进水SS浓度和进水pH值.研究表明,电解浮选是高效的固液分离单元,水力停留时间和电流密度是主要的影响因素.SS的去除率随着水力停留时间和电流密度的增加而增大;污泥负荷增加,SS的去除率下降;pH值影响电解产生微气泡的尺寸和污泥性质,但对SS的去除影响不大,实际应用中可以不调节pH值.进水SS约1 000mg/L时,当水力停留时间为20min,接触室电流密度为5 mA/cm²,分离区电流密度为2.5 mA/cm²,SS的去除率可达97%以上,此时的能耗为0.4～0.5(kW.h)/m³废水.电解浮选产生的浮渣含水率为95.9%,低于溶气气浮和二沉池的污泥含水率,对污泥减量化及其最终处置有较大的意义.