介质阻挡放电降解苯乙烯的研究

研究了介质阻挡放电(DBD)常压下降解流动态苯乙烯时,不同电压、流速、初始浓度及湿度下苯乙烯的降解情况.结果表明,DBD降解苯乙烯15~20min即可达稳定,产物主要为CO、CO₂和H₂O;电压4800V时有少量带苯环的气态及固态物质产生,且随电压的升高而减少,到7500V时红外光谱已无法检测到;高电压下放电可以取得90%左右的降解率,产生带苯环的气态物质和结焦物质较少.流速在1.5cm/s,浓度为3000mg/m³,相对湿度为20%左右时,降解效果最好.     

热处理温度对热障涂层微观形貌及元素互扩散的影响

目的提高热障涂层抗氧化性能,并减小二次反应区的形成。方法采用真空电弧离子镀技术在二代单晶高温合金DD32表面制备NiCoCrAlYHf(HY5)金属粘结层,分别在870℃及1000℃下进行真空扩散处理,利用电子束物理气相沉积(EB-PVD)技术制备氧化钇部分稳定氧化锆(YSZ)陶瓷层。采用扫描电子显微镜(SEM)、电子探针(EPMA)以及能谱(EDS)等测试方法,研究高温循环氧化过程中热障涂层的微观形貌、成分及扩散机制,同时计算了1、125 h氧化时间下Al元素互扩散系数。结果经过1000℃热循环、1000℃热处理的涂层氧化质量增量的绝对值较小,氧化速率常数为7.21×10-4,抗循环氧化性能较好。1100℃热处理试样,从涂层表面到基体方向Ni、Al、Cr等元素分布都比较均匀,在涂层与基体界面处,元素含量变化较为平滑。870℃热处理试样,Ni等元素质量分数分布不均,在涂层与基体界面处元素含量陡然变化,元素均质化程度低。Al元素扩散系数随着浓度的增加而增大,随着氧化时间的延长,粘结层与高温合金之间的元素扩散程度加剧,Al元素扩散系数减小。经过125h循环氧化,粘结层/基体界面出现互扩散区,互扩散区局部区域富Cr,Al含量低。循环氧化250 h后,热障涂层试样扩散区下方有拓扑密堆相TCP析出,形成二次反应区SRZ。真空扩散温度为870℃的试样,二次反应区更加明显。结论金属粘结层在1000℃下进行真空热处理可以有效提高涂层的抗氧化性能。涂层内部元素均质化程度高,Al元素扩散速率慢。同时,扩散区宽度较小,二次反应区不明显。     

EK∕PRB修复砷污染土壤影响因素及机理

为明确EK/PRB（电动联合渗透反应格栅）修复As污染土壤过程中各因素的影响机理、提高As的去除效率,以As污染高岭土为研究对象,考察PRB加入、PRB位置、pH调控及腐殖酸强化影响下,EK/PRB系统中电流密度、土壤pH分布和土壤中As残余量、电渗透系数及电渗流的变化规律;探讨EK/PRB修复后土壤中As形态的迁移转化规律.结果表明:①单独EK修复对土壤中As的去除效率较低,加入PRB后去除率为由42%增至57%,并且EK/PRB修复可以将土壤中的As由不容易去除的可还原态转变成较容易去除的酸溶态.②采用盐酸调节阴极pH,可以将土壤中As的去除率由57%增至63%,但同时能耗也明显升高,由5.22 kW·h/g升至39.38 kW·h/g.③添加腐殖酸会促进土壤中As的迁移、提高As的去除效率,但也会增加土壤中难处理的可氧化态和残渣态As的占比.研究显示,EK/PRB除As过程中以PRB的去除作用为主,阴极pH调控及腐殖酸强化均可以提高土壤中As的去除率.      

地下水原位修复渗透性反应墙反应介质的改良与展望

渗透性反应墙(PRBs)是倍受关注的地下水原位修复技术之一,具有高效廉价、安装简便、维护简单等优点。详细总结了零价铁、活性炭、无机矿物材料和生物质材料等PRBs反应介质的结构、性能、适用范围、改良方法及增强吸附机制,介绍了PRBs技术在国内外地下水原位修复领域的工程应用实例,指出研发可再生型反应介质、深入研究复杂体系的污染物去除主导机制以及开展多介质混合、多种原位修复技术集成应用研究将是今后PRBs的主要研究方向。     

阻挡放电联合金属氧化物催化降解H2S的研究

采用介质阻挡放电联合金属氧化物催化降解气态H2S,考察了单组分及复合金属氧化物催化剂、催化剂与低温等离子体结合方式对H2S及副产物O3去除性能的影响,分析了等离子体联合Mn复合金属氧化物催化降解H2S机理。结果表明,金属负载量相同条件下,电压低于22kV时,Mn复合金属氧化物对H2S的催化活性高于单组分Mn金属氧化物,催化活性及对O3的分解能力从大到小依次为:Ag+Mn、Cu+Mn、Fe+Mn、Mn。当电压为18 kV时,Ag+Mn、Cu+Mn、Fe+Mn复合催化剂分别比单组分Mn催化剂对H2S的去除效率提高了近10%、6%、4%。等离子体后催化区域中Mn催化剂催化氧化H2S的效率明显低于等离子体催化区域。Mn催化剂在等离子体后催化区域中能有效催化分解O3。随着电压的升高,Mn金属氧化物在等离子体后催化区域对H2S催化作用逐渐增强。在电压22 kV时,等离子体联合后催化比单独等离子体作用时,H2S去除效率提高了近11%。     

Prioritization of applicable drivers for green supply chain management implementation toward sustainability in Thailand

ABSTRACT

It is essential that the green supply chain management (GSCM) implementation is effectively supported by several strategic drivers for successful implementation and sustainability, especially for the ‘green’ start-ups with a sustainability-driven organizational strategy. This study aims to determine and prioritize the applicable drivers for GSCM implementation of sustainable development strategies in the electronics industry in Thailand. The applicable drivers and their priorities are obtained by applying the fuzzy group decision-making approaches including fuzzy Delphi and fuzzy Analytic Hierarchy Process, based on Thai experts’ perspectives. In this study, three prominent organizational theories, resource-based view, relational view, and institutional theory, are needed to explain the drivers of sustainability and to develop a hierarchical model for prioritization of the drivers. Finally, based on the findings of this study, several recommendations are made that may help to improve the sustainable development in Thailand through more effective implementation of GSCM.     

电子束物理气相沉积制备热障涂层研究进展

介绍了电子束物理气相沉积设备的主要组成、工作原理和电子束物理气相沉积热障涂层的结构特点,并重点论述了工件转速、工件温度、靶材蒸汽入射角度、工件表面的粗糙度、粘结层预氧化、改性粘结层和双层陶瓷层等对电子束物理气相沉积热障涂层性能的影响。     

Ecogenetic features and functions of solods in transural forest-steppes (within Sverdlovsk Oblast)

Specific ecogenetic features of solods in the forest-steppe zone has been studied, and the role of biotic and abiotic factors of soil formation has been estimated. Differentiation of soil horizons with respect to the physical clay fraction accounts for specific features of their moistening, which is reflected in the ratio of strongly and weakly crystallized forms of iron. Periodic changes in redox conditions results in iron segregation, and a high content of fulvic acids accounts for its eluvial migration. These processes are controlled by soil geochemical barriers.     

Global Trend of Low-carbon Economy and China's Responses

Based on the analysis on the global economic crisis,climate change crisis and their mutual underlying reasons,the authors believe that low-carbon economy has become an inevitable choice to break through the dual crises,coordinate the economic development,and protect the global climate.The global trend of low-carbon economy finds expression in Green Recovery currently,while,in a long run,it will give rise to a new pattern of world competition in politics,economy,technology,trade and finance.The impact of the...