岩溶流域土地利用变化对地下水水质的影响——以云南小江流域为例

利用1982、2003年土地利用现状图、地下水水质资料和监测数据,在GIS支持下,研究云南小江岩溶流域20年来的土地利用变化及其水文环境效应。结果表明:20年来,流域610.12km₂的土地利用面积发生变化;土地利用变化的主要过程是由未利用地向耕地和林地以及林地向耕地的转化;土地利用的空间格局发生很大变化,空间格局指数有不同程度的增加或减少;地下水水质的变化与土地利用变化表现出动态一致性,林地和未利用地转变为耕地后,地下水的总硬度、总碱度、pH值、SO42-、NO3-、Ca2+等离子值明显升高,并形成明显的高值区;1982年流域地下水以I、II、III级水质为主,而2003年流域却以IV、V级水质为主,地下水水质呈明显恶化趋势;流域地下水水质的变化与流域森林质量下降以及耕地扩张带来的化肥污染息息相关。     

苏北辐射沙洲海岸带农业景观生态分析与优化设计

在世界上具有独特环境资源意义的苏北辐射沙洲位于南黄海西南隅,其不断并岸成陆产生大片开发潜力巨大的农用土地资源.但目前存在诸如岸线冲淤、生态脆弱、过度与无序开发等环境资源问题.在实地综合调研的基础上,运用景观生态学的基本理论,对区域农业景观空间格局进行调整与优化设计,提出促进区域农业生态-经济-美学多重价值同步提高,实现持续农业的有效途径,并以具典型特征的如东县作为个案分析,提出了调整与优化设计的建议.     

水电建设区的生态环境监测与评价——以向家坝水电站为例

水电工程的建设对区域环境会产生不可逆转的重大扰动,生态环境监测与预警作为大型水电工程建设的重要环节,为工程区域环境问题分析与研究提供详实的数据支撑,对区域生态环境的修复至关重要。以向家坝水电站为例,分析水电工程建设对区域环境产生扰动的特点,结合产生扰动的各环境要素,构建工程施工区环境监测体系。收集、整理相关监测数据,采用环境因子综合评价法对监测的相关数据进行分析和评价,结合各种环境因子的现状以及变化过程、总结区域环境总体状况的变化规律及空间分布。结果表明：自2007年工程大规模动工以来,区域的生态脆弱度大幅度升高,2008年达到顶峰,自2009年起环境开始改善,保持优于2007、2008年的状况;最脆弱区域为主体工程和云天化生产区交接地区,低度脆弱区域为河流及工程量少的加工工程区域;工程扰动最大的区域、当地工业区及交通枢纽集中地带是建设区环境最脆弱的区域,工程建设、工业及交通是建设区的主要扰动因素     

电动车火灾事故原因及预防措施分析

为研究电动车火灾事故原因并提出相应的预防措施,本文选取近年来发生的50起电动车火灾事故作为案例,运用5Why分析法分析电动车火灾发生原因和造成人员伤亡的原因,并针对性提出居民预防事故的对策措施。结果表明:导致电动车火灾事故发生的原因主要有电动车电池发生短路、电动车线路短路、其他外因火灾和电动车本身具有可燃性,而人员伤亡的原因有人员逃生困难和灭火困难,并针对事故原因提出规范日常使用、排查火灾隐患等改进建议。通过上述研究结论,对电动车火灾原因分析和措施研究具有理论意义,对规范居民日常电动车使用和培养安全意识具有实践意义。     

工业场地碱污染土壤修复工程案例研究

文章主要介绍了江苏某化工场区域内碱污染土壤酸碱中和修复工程。根据场地特点,针对性的将污染土壤分为重污染土壤、中污染土壤和轻污染土壤来修复。通过现场中试,确定了3种污染土壤盐酸掺加比和浓度;其中重污染土壤掺加量为25mol／m^3,中污染土壤掺加量为2．5mol／m^3,轻污染土壤掺加量为0．25mol／m^3。根据中试结果,对污染土壤进行工程修复,修复过程中对土壤进行实时检测。工程施工结束后,由第三方机构对修复效果进行评估;评估结果为场地碱污染土壤pH值总体达到修复目标（pH为7～9）,修复达标。     

Identification of long-range transport pathways and potential sources of PM2.5 and PM10 in Beijing from 2014 to 2015

Trajectory clustering, potential source contribution function (PSCF) and concentration-weighted trajectory (CWT) methods were applied to investigate the transport pathways and identify potential sources of PM_2.5 and PM₁₀ in different seasons from June 2014 to May 2015 in Beijing. The cluster analyses showed that Beijing was affected by trajectories from the south and southeast in summer and autumn. In winter and spring, Beijing was not only affected by the trajectories from the south and southeast, but was also affected by trajectories from the north and northwest. In addition, the analyses of the pressure profile of backward trajectories showed that backward trajectories, which have important influence on Beijing, were mainly distributed above 970 hPa in summer and autumn and below 950 hPa in spring and winter. This indicates that PM_2.5 and PM₁₀ were strongly affected by the near surface air masses in summer and autumn and by high altitude air masses in winter and spring. Results of PSCF and CWT analyses showed that the largest potential source areas were identified in spring, followed by winter and autumn, then summer. In addition, potential source regions of PM₁₀ were similar to those of PM_2.5. There were a clear seasonal and spatial variation of the potential source areas of Beijing and the airflow in the horizontal and vertical directions. Therefore, more effective regional emission reduction measures in Beijing''s surrounding provinces should be implemented to reduce emissions of regional sources in different seasons.     

我国注册安全工程师注册现状分析

根据注册安全工程师初始注册申请表以及注册安全工程师注册信息管理数据库、国家安全生产监督管理总局和人事部人事考试中心提供的数据,对目前已注册的17441名注册安全工程师的年龄结构、学历结构、安全生产相关工作年限和受聘单位性质进行了统计分析。结果表明,我国现有注册安全工程师年龄、学历结构合理,但数量上仍不能满足需要。笔者提出应通过制订考试标准等方式加快注册安全工程师专业技术人才队伍建设的建议。     

Modeling study on the roles of the deposition and transport of PM2.5 in air quality changes over central-eastern China

The role of PM_2.5 (particles with aerodynamic diameters ≤ 2.5 µm) deposition in air quality changes over China remains unclear. By using the three-year (2013, 2015, and 2017) simulation results of the WRF/CUACE v1.0 model from a previous work (Zhang et al., 2021), a non-linear relationship between the deposition of PM_2.5 and anthropogenic emissions over central-eastern China in cold seasons as well as in different life stages of haze events was unraveled. PM_2.5 deposition is spatially distributed differently from PM_2.5 concentrations and anthropogenic emissions over China. The North China Plain (NCP) is typically characterized by higher anthropogenic emissions compared to southern China, such as the middle-low reaches of Yangtze River (MLYR), which includes parts of the Yangtze River Delta and the Midwest. However, PM_2.5 deposition in the NCP is significantly lower than that in the MLYR region, suggesting that in addition to meteorology and emissions, lower deposition is another important factor in the increase in haze levels. Regional transport of pollution in central-eastern China acts as a moderator of pollution levels in different regions, for example by bringing pollution from the NCP to the MLYR region in cold seasons. It was found that in typical haze events the deposition flux of PM_2.5 during the removal stages is substantially higher than that in accumulation stages, with most of the PM_2.5 being transported southward and deposited to the MLYR and Sichuan Basin region, corresponding to a latitude range of about 24°N-31°N.     

管流式冲刷腐蚀实验装置的设计及性能试验

研究腐蚀因素对管道内壁腐蚀机理与腐蚀行为的影响,为加速管道内壁腐蚀,自主设计一种管流式冲刷腐蚀实验装置。该装置属于机电一体化产品,包括总体结构设计、控制系统硬件设计和软件设计,其中控制系统PLC为中央处理器,触摸屏为人机控制界面,并对腐蚀因素温度和流速进行调控。另外,对装置进行性能试验。结果显示,温度的控制精度可达到-0.5～+0.8℃,流速的控制精度可达到±0.01 m/s。该装置运行可靠,测试范围较广,装置性能较好,为管道冲刷腐蚀研究奠定实验基础。     

Real-world gaseous emission characteristics of natural gas heavy-duty sanitation trucks

As compared to conventional diesel heavy-duty vehicles, natural gas vehicles have been proved to be more eco-friendly due to their lower production of greenhouse gas and pollutant emissions, which are causing enormous adverse effects on global warming and air pollution. However, natural gas vehicles were rarely studied before, especially through on-road measurements. In this study, a portable emission measurement system (PEMS) was employed to investigate the real-world emissions of nitrogen oxides (NOx) (nitrogen monoxide (NO), nitrogen dioxide (NO₂)), total hydrocarbons (THC), carbon monoxide (CO), and carbon dioxide (CO₂) from two liquified natural gas (LNG) China V heavy-duty cleaning sanitation trucks with different weight. Associated with the more aggressive driving behaviors, the vehicle with lower weight exhibited higher CO₂ (3%) but lower NOx (48.3%) (NO₂ (78.2%) and NO (29.4%)), CO (44.8%), and THC (3.7%) emission factors. Aggressive driving behaviors were also favorable to the production of THC, especially those in the medium-speed range but significantly negative to the production of CO and NO₂, especially those in the low-speed range with high engine load. In particular, the emission rate ratio of NO₂/NO decreased with the increase of speed/scaled tractive power in different speed ranges.