Heavy metal exposure has adverse effects on the growth and development of preschool children

Environmental Geochemistry and Health - The purpose of this study was to investigate the associations between levels of lead (Pb), cadmium (Cd), chromium (Cr), and manganese (Mn) in the PM2.5 and...     

城市污泥对不同质地土壤保水效果研究

利用城市污泥滞水性强的特性可开发污泥作为保水剂的新功能。通过土培实验,在砂土、壤土和粘土中加入不同质量的污泥,研究污泥对不同质地土壤的保水效果。结果表明:在充分供水条件下,添加污泥能显著提高3种质地土壤的持水能力,土壤中添加20%的污泥后,砂土、粘土和壤土初始含水率分别增加11.2%、8.7%和8.8%;在3种质地土壤中添加污泥均可增大土壤的保水性,使水分蒸发减慢,且污泥添加量越多,土壤含水率越大;土壤累积失水量主要受到土壤中含水量的影响,也和不同质地土壤自身的蒸发量有关;在150 g土壤中添加10 g污泥,对砂土保水性提高不大,对壤土保水性提高最大,随着添加污泥量的增多,污泥对砂土的保水效果提高最明显。研究表明:开发污泥做为保水剂是可行的,这为污泥的资源化利用提供了新的途径,也为复合保水剂的研制提供了新的廉价材料,对于污泥治理及农业节水都有重要意义。     

混合溶剂的闪点变化规律探析

为考察不同类型溶剂对混合液易燃特性的影响,探索混合溶剂闪点的变化规律,分别将不燃溶剂、阻燃型溶剂、高闪点溶剂及低闪点溶剂与乙醇按不同比例混合,采用闭杯闪点测试仪进行混合液的闪点测试。研究结果表明,添加不燃或阻燃溶剂时,混合液闪点整体呈现逐渐升高趋势,不燃或阻燃溶剂易于提高混合溶剂的安全性能,当不燃或阻燃溶剂体积分数超过0.7以上时,混合液闪点提高幅度较大;添加可燃溶剂时,可燃溶剂的结构不同,对混合液的燃烧特性影响也不同,添加高闪点溶剂可能提高混合液闪点,也可能降低混合液闪点;而添加低闪点溶剂,降低混合液闪点,甚至可能比混合液任一组分闪点值都低;因此选用混合溶剂时,不能盲目,需要严格关注其混合后易燃特性参数的变化。     

如何搞好国有大中型亏损企业的环境保护工作

本文揭示了目前在国有大中型亏损企业中开展环境保护工作的困难与问题，指出这是关系到实现我国中目标的重大课题，并提出了一系列搞好国有大中型亏 企业环境工作的对策和措施，希望能引起社会各界特别是国有大中型企业领导们的重视。     

清代综合治理黄河下游水患的系统科学思想

利用清代在治黄斗争中留下的历史文献, 对清代治理黄河的系统科学思想进行初步的研究与总结, 目的是鉴古知今, 为当代治理好黄河提供借鉴与创意。     

许昌市浅层地下水中离子总量与电导率间关系的研究

通过实验,用回归分析法,研究了许昌市浅层地下水中离子总量与电导率间的定量关系,可用电导法快速了解水质中的离子总量和衡量水质全分析中主要被测离子总和的质量.     

用灰色系统理论对新疆主要河流水质进行预测和分析

在对新疆河流水质现状进行分析评价的基础上,用GM(1,1)模型对今后五年内的河流水质进行了预测。     

氯化钡废液联产氢氧化钙和氯化钡

讨论了氯化钡废液联产氢氧化钙及高纯氯化钡的方法和主要影响因素。通过复盐共沉淀、热滤、结晶、精制纯化等工序,用氯化钡的蒸发残液制得了工业级的氢氧化钙和高纯度氯化钡,其纯度分别达95％和99．92％以上。采用有机溶剂析出法精制氯化钡,无需重结晶工序,是对传统工艺的一种改进。     

The impact of government incentives and penalties on willingness to recycle plastic waste: An evolutionary game theory perspective

• Punishments increase the participation probability of collectors and recyclers. • Policy-sponsored incentives make collectors and recyclers to participate earlier. • Recyclers are more sensitive to government punishments than collectors. Because governments have introduced policies involving incentives and penalties to promote the recycling of plastic waste, it is important to understand the impact of such incentives and penalties on the willingness of stakeholders to participate. In this study, government is included as a player, alongside waste collectors and recyclers, in a tripartite evolutionary game model of plastic waste recycling. The study explores the evolutionary equilibrium and performs a simulation analysis to elucidate the effect of government incentives and penalties on the willingness of other players to participate in recycling. Three conclusions are drawn from this research. First, an increase in incentives or in penalties increases the probability that collectors and recyclers will participate in the recycling process. Second, policy support incentives encourage collectors and recyclers to participate in plastic waste recycling earlier than subsidy incentives do. Finally, recyclers are more sensitive than collectors to government-imposed penalties.