国内外农用地膜使用政策、执行标准与回收状况

农用地膜覆盖技术具有良好的增温、保墒、除草等作用,已成为中国农业生产上不可或缺的农艺措施,为作物增产增收和保障中国粮食安全做出了巨大贡献。由于长期重使用、轻回收,随着农用地膜的用量和覆膜年限增加,废旧地膜在土壤中的残留量逐年增多,残膜污染已严重影响农业生产和自然环境,成为影响中国农业可持续发展的突出问题。中国的农用地膜污染防治工作总体起步较晚,虽然取得了一定成效,但还面临着政策不健全,监管有难度,执行不到位,回收、替代技术不成熟等困难和问题,防治任务依然艰巨。文章通过深入分析欧美与日本发达国家农用地膜推广使用方面的相关政策及标准,总结归纳了国内外农用地膜管理和回收经验,为今后制定出台适应中国国情的农用地膜管理政策提供参考。建议:(1)推进全程监管,出台相关法律规章,明确生产、流通、使用等各环节的监管责任,建立全程监管体系,从源头上杜绝脱标地膜进入市场、铺进农田;(2)推进源头减量,开展地膜覆盖技术适宜性评价,强化地膜使用控制,对水热资源条件较好的地区,减少地膜覆盖或不再使用地膜,对资源禀赋较差的地区,提高地膜使用效率,降低使用强度;(3)推进回收利用,推动完善政府扶持、市场主导的农膜回收利用体系,探索农膜回收利用长效机制,推动建立区域性绿色补贴政策;(4)推进技术创新,依托科技平台,加大新产品、新设备的研发力度,加强可降解地膜产品和技术跟踪,制定完善评价标准体系。     

Transmembrane transport of polycyclic aromatic hydrocarbons by bacteria and functional regulation of membrane proteins

• Explaintheadsorption, uptake and transmembrane transport of PAHs by bacteria. • Analyze functional regulation of membrane proteins inthe transmembrane transport. • Proteomics technology such as iTRAQ labeling was used to access expressed proteins. • Single cell analysis technology wereused to study the morphological structure. In recent years, increasing research has been conducted on transmembrane transport processes and the mechanisms behind the microbial breakdown of polycyclic aromatic hydrocarbons (PAHs), including the role of membrane proteins in transmembrane transport and the mode of transmission. This article explains the adsorption, uptake and transmembrane transport of PAHs by bacteria, the regulation of membrane protein function during the transmembrane transport. There are three different regulation mechanisms for uptake, depending on the state and size of the oil droplets relative to the size of the microbial cells, which are (i) direct adhesion, (ii) emulsification and pseudosolubilization, and (iii) interfacial uptake. Furthermore, two main transmembrane transport modes are introduced, which are (i) active transport and (ii) passive uptake and active efflux mechanism. Meanwhile, introduce the proteomics and single cell analysis technology used to address these areas of research, such as Isobaric tags for relative and absolute quantitation (iTRAQ) technology and Nano Secondary ion mass spectrometry (Nano-SIMS). Additionally, analyze the changes in morphology and structure and the characteristics of microbial cell membranes in the process of transmembrane transport. Finally, recognize the microscopic mechanism of PAHs biodegradation in terms of cell and membrane proteins are of great theoretical and practical significance for understanding the factors that influence the efficient degradation of PAHs contaminants in soil and for remediating the PAHs contamination in this area with biotechnology.     

区域龙头企业对地方政府环境规制影响研究

当政府基于公共利益对企业实施规制,政府所代表的公共利益与龙头企业的经济利益冲突时,政府的规制行为与规制效率是否会受龙头企业影响?已有的研究较少涉及这一公共管理的重要问题。本研究从环境规制视角出发,基于1999—2013年的中国31个省级层面的面板数据,结合工业企业数据库微观数据,在省级层面实证检验了当存在利益冲突和规制能力约束时,区域环境规制水平是否会受到龙头企业以规模衡量的能力影响;如是,其方向和机制又是什么。本文研究发现:(1)龙头企业规模越大,区域环境规制水平越严格;(2)龙头企业规模对区域环境规制的影响主要通过两种路径实现,一是龙头企业所在行业的区域经济地位,行业的区域经济地位越重要,越容易引来政府的环境规制关注;二是龙头企业在所在行业的经济地位,某企业在行业的比重越高,越容易引来政府的环境规制关注;(3)龙头企业规模与区域环境规制水平间关系是政府有限环境规制能力有效运用的结果,当政府规制能力不足时,政府在规制中会"抓大放小",重点加强对龙头企业的环境规制;随着政府规制能力上升,企业规模与区域环境规制水平的正相关关系不仅回归系数会逐步下降,而且会在统计上不再显著;最终,当政府掌握充分的环境规制能力后,企业的规模可能会在降低区域环境规制水平上发挥一定作用。本文的研究结果证实当政府与企业存在利益博弈时,政府的利益首先得到满足,仅当政府的利益得到满足后,企业才可能利用其实力影响政府规制以获取规制利益最大化。本文的研究一方面消除了"政商勾结"污染环境的忧虑,另一方面也提示要严格限制政府这只"看得见的手"的利益诉求范围。     

Off-design performance analysis of a transcritical CO2 Rankine cycle with LNG as cold source

The transcritical CO₂ Rankine cycle with liquefied natural gas (LNG) as cold source is a promising power system to utilize mid- and low-temperature heat source. Most previous works focused on thermodynamic and thermoeconomic analysis or optimization for the system. In this article, an off-design performance analysis for the system is conducted. An off-design mathematical model for the system is established to examine the variation of system performance with the variations of heat source mass flow rate and temperature. A modified sliding pressure regulation control strategy, which regulates turbine inlet pressure to keep the temperature difference between heat source temperature and turbine inlet temperature constant, is applied to control the system when off-design conditions happen. The results show that when the mass flow rate or the temperature of heat source is less or lower than that of design condition, both the net power output of system and the system exergy efficiency decrease, whereas when they are more or higher than the values of design condition, the net power output of system increases but the system exergy efficiency still decreases. In addition, both CO₂ turbine and NG turbine could almost keep the designed efficiency values under the applied control strategy.     

金属熔炼企业辐射安全监管的探讨

随着金属熔炼行业的迅速发展,熔炼企业出现放射性污染事件的风险日益增加,采取有效措施加强金属熔炼企业辐射安全监管,防止放射性污染事件的发生,具有十分重要的意义。为规范金属熔炼企业的辐射安全管理,浙江省开展了"放心熔炼企业"创建工作,对金属熔炼企业从管理机构、管理制度、仪器配备、人员培训、台账管理等方面提出了严格的管理要求。本文在对浙江省金属熔炼企业辐射安全管理现状情况进行详细调查并结合日常监督性检查和监测的基础上,分析了目前金属熔炼企业辐射安全监管中存在的主要问题,提出了建立有效的管理措施、加强人员培训、加强仪器配备、多部门合作共同做好金属熔炼行业辐射安全监管工作等对策、措施和建议。     

Jobs and climate policy: Evidence from British Columbia's revenue-neutral carbon tax

This paper examines the employment impact of British Columbia's revenue-neutral carbon tax implemented in 2008. While all industries appear to benefit from the redistributed tax revenues, the most carbon-intensive and trade-sensitive industries see employment fall with the tax, while clean service industries see employment rise. By aggregating across industries I find the BC carbon tax generated, on average, a small but statistically significant 0.74 percent annual increases in employment over the 2007–2013 period. This paper provides initial evidence showing how a revenue-neutral carbon tax may not adversely affect employment.     

循环流动系统的压力调节及能量消耗问题

本项目对立式循环流动系统内气体压力、流量变化的调节控制方法,通风机的能量消耗等实际工程问题,进行了一系列的试验研究。其研究成果可以用于其他工程设计项目,对提高我国通风除尘系统的设计质量有一定的现实意义。     

垃圾渗滤液氨态氮与挥发性脂肪酸馏出规律研究

为了提高垃圾渗滤液氨态氮（NH4^＋-N）与挥发性脂肪酸（VFA）联合滴定分析结果的准确性,试验研究了NH4^＋-N与VFA的馏出规律,并在此基础上对联合滴定方法的优化进行了探讨。结果表明：测得的NH4^＋-N质量浓度（Y1）、VFA浓度（Y2）与馏出液体积（X）分别符合函数关系式;联合滴定分析过程中,渗滤液样品NH4^＋-N质量浓度应稀释至150mg／L-200mg／L,NH4^＋-N馏出液应大于蒸馏液体积的60％;VFA分析应采用“一次蒸馏80％＋二次蒸馏”的方式,且VFA二次馏出液应大于蒸馏液体积的75％（相对误差限εr〈5％）。     

环境监测技术竞赛方案设计

技术竞赛是促进监测水平提高的好方法,经过多次技术竞赛活动,制定出一套较科学适用的实施方案,基础理论采用笔试,样品测试采用尤登双样图。并设计出程序文件和测试样品配制方法,实际应用效果良好。     

水质监测中存在的若干技术问题

在全国持证上岗、计量认证、实验室现场考核和《亚洲地区实验室精度管理手册》编制过程及监测质量调查的基础上,发现我国部分环境监测站在水质监测的实际操作、试样前处理、监测分析方法选择及数据分析等方面尚存在一些技术问题。在分析这些问题的同时,提出了解决办法和完善我国质量保证指标体系的建议。