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531.
This study proposes a new approach for diosgenin production from Dioscorea zingiberensis C. H. Wright tubers with respect to resources utilization and clean production. This process consisted of two successive parts, i.e., recovery of starch from raw material, and microbial hydrolysis of the residue to produce diosgenin by Trichoderma reesei. In the first step, about 75.4% of hemicellulose and 98.0% of starch were removed from the tubers. In the second step, about 90.2% of diosgenin was released from saponins by T. reesei at 30 °C, at an aeration of 0.80 vvm and agitation rate of 300 rpm in a 5.0 L bioreactor. Significant reduction of pollutant production was detected by replacing the traditional approach with the proposed new method. About 99.2% of reducing sugar, 99.4% of chemical oxygen demand, 99.2% of total organic carbon, 100% of SO42?, and 100% of acid was reduced in the new processing wastewater.  相似文献   
532.
Characteristics of toluene decomposition and formation of nitrogen oxide (NOx) by-products were investigated in a dielectric barrier discharge (DBD) reactor with/without catalyst at room temperature and atmospheric pressure. Four kinds of metal oxides, i.e., manganese oxide (MnOx), iron oxide (FeOx), cobalt oxide (CoOx) and copper oxide (CuO), supported on Al2O3/nickel foam, were used as catalysts. It was found that introducing catalysts could improve toluene removal efficiency, promote decomposition of by-product ozone and enhance CO2 selectivity. In addition, NOx was suppressed with the decrease of specific energy density (SED) and the increase of humidity, gas flow rate and toluene concentration, or catalyst introduction. Among the four kinds of catalysts, the CuO catalyst showed the best performance in NOx suppression. The MnOx catalyst exhibited the lowest concentration of O3 and highest CO2 selectivity but the highest concentration of NOx. A possible pathway for NOx production in DBD was discussed. The contributions of oxygen active species and hydroxyl radicals are dominant in NOx suppression.  相似文献   
533.
534.
Environmental quality in urban areas has become an increasingly important topic in Taiwan. Previous research involving the interrelationshipsbetween urban development and environmental quality have rarely emphasized the symbiosis between urban areas and the natural environment. In recent years, the discipline of ecological economics has applied ecological energetic analysis to evaluate the contribution of the natural environment to an urban system. In addition, system simulation also plays a prominent role in assessing the dynamic interrelations between humans, economics and ecological systems. On the basis of an ecological economics perspective, this paper establishes indices of environmental quality and develops an ecological system model to simulate the interrelationshipsbetween urban developmentand environmentalquality of the Taipei metropolitan region. Furthermore, this paper not only proposes future development alternatives and strategies, but also initiates scenarios of the Taipei metropolitan region for policy simulation. According to those results, future development in the Taipei metropolitan region should adjust the interface and mechanism between man and nature for sustainable development.  相似文献   
535.
536.
Microcystin-LR(MC-LR) is the most abundant and toxic microcystin congener and has been classified as a potential human carcinogen(Group 2B) by the International Agency for Research on Cancer. However, the mechanisms underlying the genotoxic effects of MC-LR during chronic exposure are still poorly understood. In the present study, human–hamster hybrid(AL) cells were exposed to MC-LR for varying lengths of time to investigate the role of nitrogen radicals in MC-LR-induced genotoxicity. The mutagenic potential at the CD59 locus was more than 2-fold higher(p 0.01) in ALcells exposed to a cytotoxic concentration(1 μmol/L) of MC-LR for 30 days than in untreated control cells, which was consistent with the formation of micronucleus. MC-LR caused a dose-dependent increase in nitric oxide(NO) production in treated cells. Moreover, this was blocked by concurrent treatment with the NO synthase inhibitor NG-methyl-L-arginine(L-NMMA), which suppressed MC-LRinduced mutations as well. The survival of mitochondrial DNA-depleted(ρ0) ALcells was markedly decreased by MC-LR treatment compared to that in ALcells, while the CD59 mutant fraction was unaltered. These results provided clear evidence that the genotoxicity associated with chronic MC-LR exposure in mammalian cells was mediated by NO and might be considered as a basis for the development of therapeutics that prevent carcinogenesis.  相似文献   
537.
Modern work is frequently characterized by jobs where adaptive performance (AP) is crucial for employees to succeed in light of new or altered task demands. This recognition has fueled growing interest in AP as a dimension of workplace performance. To this point, however, research on AP has evolved from disparate perspectives and methods, resulting in fragmentation and a less than coherent knowledge base. This paper presents a comprehensive review of research studies regarding the nomological network of individual AP. In doing so, we synthesize the current knowledge base surrounding correlates of AP, elucidate current ambiguities, and suggest directions for future research efforts. We conclude that although the extant AP literature has amassed a critical body of studies linking various predictors to successful AP outcomes, much remains unknown, most critically regarding the implications of different methods of assessing AP, the effects of different types of changes in the task environment, the process of AP, and the steps organizations can take to foster AP among their employees. We hope that our synthesis and analysis paves the way for efforts to address these important questions. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
538.
This paper examines whether foreign aid, together with other economic, social and environmental factors, contributes to sustainable development. It starts with an illustrative theoretical growth model where foreign aid promotes sustainable development by protecting the environment. Using factor analysis and newly developed estimation methods for a dynamic panel data model with endogenous regressors, the empirical section of the paper finds evidence that foreign aid has had a significantly positive influence on sustainable development in aid recipient countries. This effect is very likely to go through channels related to growth and resources as well as a technology channel with respect to energy intensity. This research has important implications for a post‐2015 development framework on international collective action with regard to a sustainable future.  相似文献   
539.
从资源能源利用、废弃物产生、废弃物回收利用、污染物处理、环境管理效果和环境响应情况着手,建立了包括6个一级指标、29个二级指标的海洋石油工程清洁生产评估指标体系;研究利用专家调查和层次分析法确定各评估指标的权重值,探索评估指标的赋值方法、标准化方法,提出了海洋石油工程清洁生产综合指数计算方法体系。  相似文献   
540.
基于长江流域区域1956-2011年50年气象资料和同期太平洋海温资料,采用Z指数、EOF、REOF、SVD分析等方法,探讨长江流域春季和夏季旱涝特征及其旱涝事件与极端海温异常之间的关联性,得出以下结论。1REOF的Z指数春夏季节旱涝空间分区特征显示,春季前6个模态的累计方差贡献率能够达到61.2%,收敛速度较平缓,夏季前6个模态累积方差贡献率更低,只有52.1%。2前冬太平洋海温的变化与长江流域旱涝的态势呈显著相关关系,春季海温场与长江流域旱涝Z指数场的SVD第一模态显示,长江流域的东北区的旱涝与厄尔尼诺显著相关,当赤道东太平洋海温升高,西太平洋海温降低时,长江流域东北地区偏涝,而长江流域的西部地区偏旱,反之亦然。3夏季海温场与长江流域旱涝Z指数场的SVD第一模态,表明太平洋海温分布主要呈现南北向的分布,当赤道中东太平洋海温偏高,北太平洋海温偏低时,长江流域夏季中部地区偏涝。反之亦然。第二模态,全球海温呈现厄尔尼诺类型的分布,中东太平洋是负相关,而在西太平洋为显著负相关。  相似文献   
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