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81.
Advanced oxidation technologies are a friendly environmental approach for the remediation of industrial wastewaters. Here, one pot synthesis of mesoporous WO_3 and WO_3-graphene oxide(GO) nanocomposites has been performed through the sol–gel method. Then, platinum(Pt) nanoparticles were deposited onto the WO_3 and WO_3-GO nanocomposite through photochemical reduction to produce mesoporous Pt/WO_3 and Pt/WO_3-GO nanocomposites. X-ray diffraction(XRD) findings exhibit a formation of monoclinic and triclinic WO_3 phases. Transmission Electron Microscope(TEM) images of Pt/WO_3-GO nanocomposites exhibited that WO_3 nanoparticles are obviously agglomerated and the particle sizes of Pt and WO_3 are ~ 10 nm and 20–50 nm, respectively. The mesoporous Pt/WO_3 and Pt/WO_3-GO nanocomposites were assessed for photocatalytic degradation of Methylene Blue(MB) as a probe molecule under visible light illumination.The findings showed that mesoporous Pt/WO_3, WO_3-GO and Pt/WO_3-GO nanocomposites exhibited much higher photocatalytic efficiencies than the pure WO_3. The photodegradation rates by mesoporous Pt/WO_3-GO nanocomposites are 3, 2 and 1.15 times greater than those by mesoporous WO_3, WO_3-GO, and Pt/WO_3, respectively. The key factors of the enhanced photocatalytic performance of Pt/WO_3-GO nanocomposites could be explained by the highly freedom electron transfer through the synergetic effect between WO_3 and GO sheets, in addition to the Pt nanoparticles that act as active sites for O2 reduction, which suppresses the electron hole pair recombination in the Pt/WO_3-GO nanocomposites.  相似文献   
82.
目的研究g-C_3N_4/C-Dots-M复合材料的光电化学阴极保护性能。方法采用X射线衍射(XRD)、扫描电子显微镜(SEM)和紫外可见漫反射光谱技术对样品的晶体结构、微观形貌和光吸收性能进行表征。通过电化学测试可见光照射下g-C_3N_4/C-Dots-M复合材料光电极偶联316L不锈钢后的光电化学阴极保护电流密度和电位变化曲线,研究材料的光电化学阴极保护性能。结果可见光照射下,该偶联体系的光致混合电位下降至-0.43 V(vs. Ag/AgCl),光电化学阴极保护电流密度达到4.3μA/cm。结论得益于碳量子点优异的电子传导特性,g-C_3N_4/C-Dots-550复合材料的光电化学阴极保护性能比纯g-C_3N_4的明显增强。该复合材料在光电化学阴极保护方面展现了较大的应用潜力。  相似文献   
83.
DZ125合金HY3包覆型涂层退除研究   总被引:1,自引:1,他引:0  
目的 研究化学法退除DZ125合金HY3包覆型涂层。方法 采用真空电弧镀技术(AIP)在定向凝固镍基高温合金DZ125上制备包覆型涂层HY3,利用化学方法完全退除基体上的涂层,通过失重法研究对比1#和2#退除溶液退除HY3涂层和DZ125合金的退除速率,采用扫描电镜(SEM)对退除后的HY3涂层和DZ125基体的微观组织进行观察。结果 经过100 min,2#溶液可以将20 ?m左右的HY3涂层完全退除,采用1#溶液需要超过100 min才能完全退除涂层。两种对DZ125合金的腐蚀性很小,对于同一种合金而言,1#溶液和2#溶液对合金的腐蚀速率比值为1︰13。在1#溶液中,合金与涂层腐蚀速率的比值为1︰87.65;在2#退除溶液中,合金与涂层腐蚀速率的比值为1︰6.81。结论 1#溶液更加适合退除DZ125合金上的HY3涂层。  相似文献   
84.
针对填埋场室内模拟试验往往忽略降雨径流和初损的问题,提出运用SCS模型确定室内模拟试验日注水量的方法,并将计算结果应用于成都长安填埋场室内模拟试验中.结果表明,采用SCS模型计算所得的日入渗量进行注水的模拟柱渗滤液产量和水质变化能够更准确的模拟填埋场实际情况.  相似文献   
85.
针对目前我国环境影响评价领域普遍采用的有限边界岸边排放稳态二维混合模式的局限性和不精确性,本文对由河流二维稳态水质模型的基本方程推求出的有限边界岸边排放的二维稳态混合模式的解析解的各项进行分析比较。同时针对费休的混合长度公式进行了计算比较。  相似文献   
86.
从济南市环境保护现状调查入手,对照国家环境保护模范城市考核指标,分析济南市创建国家环境保护模范城市存在的问题,借鉴其他城市创建国家环境保护模范城市的成功经验,结合济南市实际,提出了有针对性的对策与建议。  相似文献   
87.
This paper argues on both theoretical and empirical grounds that, beyond a certain point, there is an unavoidable conflictbetween economic development (generally taken to mean 'materialeconomic growth') and environmental protection. Think for a moment of natural forests, grasslands, marine estuaries, salt marshes, and coral reefs; and of arable soils, aquifers, mineraldeposits, petroleum, and coal. These are all forms of 'natural capital' that represent highly-ordered self-producing ecosystemsor rich accumulations of energy/matter with high use potential (low entropy). Now contemplate despoiled landscapes, eroding farmlands, depleted fisheries, anthropogenic greenhouse gases,acid rain, poisonous mine tailings and toxic synthetic compounds.These all represent disordered systems or degraded forms of energy and matter with little use potential (high entropy). The main thing connecting these two states is human economic activity. Ecological economics interprets the environment-economyrelationship in terms of the second law of thermodynamics. The second law sees economic activity as a dissipative process. Fromthis perspective, the production of economic goods andservices invariably requires the consumption of available energy and matter. To grow and develop, the economynecessarily 'feeds' on sources of high-quality energy/matter first produced by nature. This tends to disorder and homogenizethe ecosphere, The ascendance of humankind has consistently been accompanied by an accelerating rate of ecological degradation, particularly biodiversity loss, the simplificationof natural systems and pollution. In short, contemporary political rhetoric to the contrary, the prevailing growth-oriented global development paradigm is fundamentally incompatible with long-term ecological and social sustainability. Unsustainability is not a technical nor economic problem as usually conceived, but rather a state of systemic incompatibilitybetween a economy that is a fully-contained, growing, dependent sub-system of a non-growing ecosphere. Potential solutions fly inthe face of contemporary development trends and cultural values.  相似文献   
88.
A modular approach to Integrated Assessment modeling   总被引:1,自引:0,他引:1  
In this paper, we present a new approach to model coupling that probably forms the methodological basis of a new generation of Integrated Assessment models. This approach respects the knowledge and expertise that is embodied in existing models and encourages their gradual evolution. Modularity is the guiding principle. Our approach is distinguished by the way modules are coupled which is based on an interplay of a job control module, a numerical coupling module, and a couple of stand-alone functional modules. The numerical coupling module - the core component - serves to treat the feedbacks between the functional modules. A first implemented example that couples an economic and a climate module by means of a two-phase meta-optimization is presented here. The algorithm and mathematical structure behind are discussed as well as important features such as convergence behavior and reliability.  相似文献   
89.
Sulfate aerosols have been found to bethe major contributors to precipitation acidity. Thus,in view of the long-term ecological repercussions theyhave on aquatic ecosystems and their acidity-potential,the present analysis focuses on a case study applicationof the layer-averaged aerosol-scavenging model (Okita et al., 1996) for predicting values of the wet scavengingcoefficient and sulfate concentrations in precipitationsamples on the basis of the information available forsome selected Indian cities. Through sensitivityanalysis (Pandey et al., 1997) the scavengingcoefficient has been found to be very strongly dependenton precipitation intensity. Comparison of modelpredictions has been done with the measured values forDelhi, Mumbai, Calcutta and Chennai in India.  相似文献   
90.
济南市环境空气中多环芳烃的来源识别和解析   总被引:4,自引:1,他引:4  
根据环境空气污染源标识物的确定和多环芳烃降解行为,利用CMB受体模型进行拟合计算,确定多环芳烃污染源贡献率,并在比较多环芳烃实测值和CMB受体模型计算值的基础上,得出可吸入颗粒物中多环芳烃源解析结果,确定机动车污染源是济南市可吸入颗粒物中多环芳烃的主要贡献源。  相似文献   
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