典型喀斯特区侵蚀性降雨特征及坡面生物措施水土流失防控效应

降雨类型和生物措施是坡面水土流失的重要影响因素。为研究喀斯特区降雨类型和不同坡面生物措施共同作用下的水土保持效益,以贵州蚂蟥田小流域水土保持监测站2014—2018年5年的径流小区实测数据为基础,分析了112场次的侵蚀性降雨特征,并以降雨量、降雨历时、平均降雨强度为指标对其进行分类。同时,分析了不同侵蚀性降雨类型下6个生物措施径流小区的产流产沙量,生物措施包括自然恢复草地、水土保持林(水保林)和经济果木林(经果林)。结果表明,侵蚀性降雨可以分为3类,通过分析降雨侵蚀力和各生物措施坡面的产流产沙能力,得出降雨的侵蚀能力表现为B雨型(中历时、大雨量、中雨强)>C雨型(短历时、小雨量、大雨强)>A雨型(长历时、中雨量、小雨强),B和C雨型的产沙量占全年总产沙量的85%以上。侵蚀性降雨集中发生在5—10月,占全年总产沙量的92.6%和总产流量的93.2%;3种生物措施的产流产沙量大小为:自然恢复草地>水保林>经果林,水保林和经果林的侵蚀产流量差异不显著(P<0.05)。对比自然恢复草地,水保林和经果林均能够减少侵蚀达50%以上。此外,其削减能力与降雨类型有关,在不同雨型下两种林地的减沙能力为:A雨型>C雨型>B雨型。研究结果可为喀斯特地区以生物措施治理坡面水土流失提供参考。     

REDD+ comes with money,not with development: an analysis of post-pilot project scenarios from the community forestry of Nepal Himalaya

Reducing emissions from deforestation and forest degradation (REDD+) attracts poor nations to keep their forest standing only to sequester carbon through monetary incentives. However, in countries like Nepal where forest is an integral part of social practices, communities need to keep using forests for making a living. Based on household survey, field interview, personal observation, and broad review of forestry legislations, this paper scrutinizes villagers’ experiences of changes in forest management after implementation of a REDD+ pilot project in nine Community Forestry Users Groups (CFUGs) of Nepal. Since REDD+ was not initiated by local communities but tacitly implemented by international NGOs, most villagers lacked knowledge about it and the associated benefits from the pilot project, thus fewer villagers were found to be motivated to participate in the pilot project. Consequently, it delinked villagers from their forest by implicitly tightening uses rules, which resulted in constraints to fetch forest products. In addition, REDD+ benefits were distributed to some poor households but not to all, which resulted to an antagonistic sentiment in the villages. Thus, a rigorous assessment of conditions and framework of REDD+ and an involvement of local community from the start without compromising in the uses of forest products is of the utmost importance before considering the REDD+ framework as an alternative or as similar to CFUG in Nepal. Alternatively, REDD+ can be a part or a development project under the CFUG’s framework, which could be socially as well as legally acceptable on the present situation.     

Pilot regulation of MnP-SA for treating PTA wastewater

In the pilot study of treating the purified terephthalic acid(PTA) wastewater with the functional Strain Fhhh in the carrier activated sludge process(CASP), the ratio of COD:TN:TP and the concentrations of Cu, Mn, Se and Zn were controlled to improve the manganese peroxidase(MnP) levels for increasing the treatment efficiency. When the ratio of COD:TN:TP was 100:0.36:0.15 and the concentrations of Cu, Mn, Se and Zn were 0.54, 5.07, 0.00 and 0.08 mg/L, the MnP specific activity(MnP-SA) reached 689 U/L, and the sludge loading rate to COD(SLRC) was 1.09 d^-1, which was 4--7 fold of that in other processes reported. The data indicated that improving MnP level could enhance the degradability of Fhhh. And the potentials of Fhhh and CASP will be also discussed in this paper.     

沸石强化A/O同步脱氮除磷工艺的生物-化学除磷研究

沸石强化了生物硝化作用,但回流的硝酸盐在A段抑制了聚磷菌释放磷,使生物脱氮工艺无除磷效果,需要化学除磷。铝盐和铁盐均具有很好的化学除磷效果,且与投加位置无关。当按磷与铝的摩尔比1∶1.5投加Al2(SO4)3·18H2O时,磷的去除率在85%以上;当按磷与铁的摩尔比1∶1投加FeSO4·7H2O时,磷的去除率在80%以上;当在A段投加20mgLFeSO4·7H2O和30mgLAl2(SO4)3·18H2O混合除磷剂能去除沸石强化AO生物脱氮工艺90%左右的磷,使磷达到出水排放标准。     

低碳试点政策对大气环境的影响及空间效应研究

考虑以低碳转型推动区域资源节约与环境友好的高质量发展，对建设人与自然和谐共生的中国式现代化具有充分现实意义。本文以三批低碳城市试点为准自然实验，基于2004—2019年中国272个城市的平衡面板数据，运用合成控制法、双重差分法和空间杜宾模型，探究低碳试点政策影响城市大气环境的作用机制及空间效应。研究发现：①低碳试点城市的大气环境质量较非试点城市得到提升，经稳健性检验后这一结论依然成立。②通过异质性分析发现，低碳试点政策对地级市和非资源城市大气环境的改善效应更为显著；相较于特大城市和小城市，大中城市更有利于放大低碳试点的政策效应。③机制分析发现，低碳试点政策通过减排溢出效应、绿色创新效应和外资限流效应促进试点城市大气环境质量的提升。④低碳试点城市的大气环境改善效应存在正向空间溢出，试点邻近城市的大气环境因此得到治理。     

企业金融化与绿色转型研究：机制识别与政策优化

实体企业金融化往往会对其经营管理决策产生重大影响。本文基于实体上市企业年报和财务数据（2007—2020年），构建其绿色转型指标，进而从理论和实证两个方面确证了金融化对绿色转型的影响与机制问题。实证结果表明，企业金融化会对其绿色转型产生显著的负面冲击，其中短期金融化行为的影响更为明显；特别地，这一冲击对重污染企业、战略性新兴企业绿色转型的影响更为显著。通过机制识别，研究发现上述冲击影响主要通过恶化财务状况、提升企业风险并降低企业预期等渠道导致企业绿色转型水平下降。进一步地，通过政策优化（如金融综合改革试验区制度）支持，上述负面效应将被显著削弱，这也说明金融体制机制的优化是降低企业金融化负面效应，提升其转型升级动力和意愿的重要路径。     

碳排放权交易试点是否促进了对外直接投资?

环境规制与跨国投资之间的关系一直是学术界关注的焦点。作为重要的环境规制手段,碳排放权交易试点的推进标志着我国环境规制强度的增强。对外直接投资(OFDI)作为最典型的跨国经济活动之一,是中国"走出去"战略的重要组成部分。近年来,中国对外直接投资存量与净额都呈现稳定的上升趋势,与此同时,环境规制强度也在不断提升。中国对外直接投资是否受到国内环境规制加强的影响值得探讨,而2013年正式启动碳排放权交易试点为解决此问题提供了一个准自然实验场景。基于此,文章使用中国30个省级行政单位2010—2019年的面板数据,以北京、上海、广东、天津、湖北、重庆和福建开展的碳排放权交易试点作为准自然实验,运用双重差分法(DID)研究碳排放权交易试点的开展是否提升了对外直接投资水平。研究结论表明,碳排放权交易试点能够显著提升我国对外直接投资水平。且该结论在平行趋势检验、合成控制法(SCM)、安慰剂检验等检验后依旧稳健。此外,潜在机制的研究发现碳排放权交易试点满足"污染避难所假说"和"波特假说",进而促进了对外直接投资水平的提升。通过净效应的初步讨论,文章发现"污染避难所假说"仍旧在目前占据主导地位。研究结论意味着:(1)未来要继续推进全国统一的碳排放权交易市场建设;(2)持续探索激发碳排放权交易试点对创新产生的激励效应;(3)完善投资便利化的制度与措施,搭建国际技术交易或信息平台等。一方面促进我国生态环境的改善,另一方面促进对外投资水平的增质提量。