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781.
水资源的持续开发和利用   总被引:15,自引:0,他引:15  
随着人品的增长和经济的发展,越来越多的国家正面临着严重的水危机、水质的恶化和水生态系统的破坏使许多国家的淡水供应出现危机,所以水资源必须得到保护和合理的开发。本文探讨了全球水资源的短缺及其原因,并提出了解决水资源短缺的途径。  相似文献   
782.
介绍了针对火电厂输煤系统作业环境粉尘治理而研制开发的新型湿式湍流除尘器的设计思路、设备结构、技术特点及在电厂输煤系统的应用情况.  相似文献   
783.
氨基染料生产过程中产生大量含有机物的铁泥,对环境造成严重污染并造成资源的极大浪费.利用超临界水氧化法对含有机物铁泥进行资源化处理研究,并对产物进行了X射线衍射分析(XRD)、色差实验与电子探针分析.研究结果显示,用超临界水氧化法处理铁泥可以将铁泥中所含的有机物完全氧化,真正实现环境友好;超临界水首先将铁泥氧化成α-Fe2O3与γ-Fe2O3,再经过800℃煅烧后可以作为氧化铁红颜料使用;超临界反应压力对样品的晶型与颜色影响不大.  相似文献   
784.
Environmental Science and Pollution Research - Co3O4 is a promising Hg0 removal catalyst for industrial application. Operating temperature and low sulfur resistance are two of the main problems...  相似文献   
785.
Environmental Science and Pollution Research - Metal-free carbonaceous composite membranes have been proven to effectively drive novel in situ catalytic oxidation for the degradation of organic...  相似文献   
786.

The high-quality development of agriculture requires not only sustainable growth of agricultural productivity but also green agricultural production. Internet technology has played an essential role in agricultural production and marketing in China over the past decades. This paper estimates provincial agricultural green growth in China from 1997 to 2019 and decomposes it into technological progress (TP) and efficiency changes (EC) based on the Luenberger productivity indicator method. Then an econometric model is employed to analyze the impact of the Internet on the growth of agricultural green productivity and each sub-component, and moderating role of farmer education in such effect. The empirical results indicated that annual average growth rate of agricultural green productivity in China is 1.33% from 1997 to 2019, and technological progress dominates its growth. The development of Internet technology has a significant positive impact on agricultural green productivity and its decomposition. Farmer education has strengthened the effect of Internet technology on agricultural green productivity and its decomposition TP and EC.

  相似文献   
787.
This review summarizes the environmental occurrence of new brominated flame retardants (NBFRs) and organophosphate compounds (OPs) in the environment of developing countries since 2000. The ban on the production and use of commercial formulations of polybrominated diphenyl ethers (PBDEs) have paved the way for the high use of NBFRs and OPs in consumer products to fulfill the fire safety regulations. Recent studies have shown that the ever increasing production volumes and extensive use of these chemicals as additive FRs and plasticizers have resulted into their ubiquitous occurrence in all environmental compartments. Although presumed to be safe for use and the environment, recent studies on their occurrence and persistence in the environment have raised questions. Due to the lack of awareness, research interest, and availability of technical facilities, limited scientific data is available on the occurrence of these chemicals in developing countries. In this study, we collected reported data and provide an overview of environmental occurrence of NBFRs and OPs in abiotic and biotic matrices of different developing countries. Finally, research gaps were identified with recommendations for future research work and would be useful towards the environmental management of these toxic chemicals.  相似文献   
788.

Sulfamethoxazole (SMX) was decomposed by using gamma irradiation in the presence of different additives such as NO3 , NO2 , Cr(VI), 2-propanol, and tert-butanol. The results demonstrated that NO3 , NO2 , 2-propanol, and tert-butanol inhibited SMX radiolytic removal. However, there existed a synergetic effect for radiolytic removal of the mixture containing SMX and Cr(VI). At an absorbed dose of 150 Gy, the removal percentages of SMX and Cr(VI) in the mixture were 73.5 and 84.6%, respectively, which was higher than the removal percentages of 70.6 and 4.1% for the single component of SMX and Cr(VI). This provides us an insight into treating the combined pollution in micro-polluted water. The SMX radiolytic removal followed a pseudo first-order reaction kinetic model, and the rate constant ratios of ·OH, eaq , and H· towards SMX radiolysis were 10.4:1:2.9. In addition, 24-h bio-inhibitory to the macroalgae of SMX solution during gamma irradiation reached the maximum of 0.85 at an adsorbed dose of 100 Gy, then gradually decreased with the increasing adsorbed dose. Based on LC-MS analysis and quantum chemical calculation, the degradation intermediates were determined and concluded that SMX radiolytic removal was mainly via ·OH radical attack and direct decomposition of SMX molecule by gamma ray.

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789.
为使石墨炉原子吸收法测金属元素准确可靠,对各测定程序和环节采取了消除干扰、测平行双样、测加标回收率、对照分析等措施。测定数据经统计分析,加标回收率在87.3%~115.2%范围内,平行双样相对偏差在12.3%以下,标准土样重复测定变异系数除镉(Cd)外均在5.9%以下,达到了分析测定的要求。  相似文献   
790.
ABSTRACT: The effect of ice cover on vertical transfer is examined based on the Reynolds' analogy and composite logarithmic velocity distributions. A finite difference scheme is used to predict concentration profiles in a two-dimensional channel. Comparisons made between the ice-covered condition and the ice-free condition show that considerable reduction in mixing capacity of the channel is caused by the ice cover.  相似文献   
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