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801.
通过四种不同的方法制备了生物防护复合面料,通过基本性能测试选取了最优方案。将以聚四氟乙稀复合膜为中间层的复合面料进行了综合性能测试,将其制成连体式防护服,并对防护服的整体性能进行了测试。结果表明:该复合面料具有优良的生物防护性和透湿性,防护服结构合理。  相似文献   
802.
In order to investigate the effect of different slope-protecting vegetation on soil restoration in the highways, we collected soils at depths of 0-10 cm, 10-20 cm, and 20-30 cm from areas planted with Amorpha fruticosa, Periploca sepium, and Paederia scandens for 6-7 years in the Daming road section of the Daguang Highway, in October 2016. The physico-chemical properties and microbial community of the soils were then analyzed. The soil microbial community was analyzed by terminal restriction fragment length polymorphism (T-RFLP). The correlation between the microbial community and the physico-chemical properties of the soils was determined by redundancy analysis (RDA). The results showed that (1) the physico-chemical properties were the best for soils with Paederia scandens; the nutrient content, water holding capacity, and porosity of the soils with the three types of slope-protecting vegetation were better in the 0-10 cm layer than in the other layers; (2) the contents of soil aggregates (diameter > 5 mm) were the highest in the 0-10 cm and 10-20 cm layers for the soil with Paederia scandens; (3) the dominant bacteria in the 0-10 cm layer and dominant fungi in the 0-10 cm, 10-20 cm, and 20-30 cm layers were higher in the soils with Pe. sepium and Pa. scandens than in the soil with A. fruticosa; and (4) results of RDA showed that the physical properties of the soils were the main factors that influenced the soil microbial community. The physical properties of the soils were sensitive to the change of soil quality. Soil quality can be improved by appropriate management measures, such as burying litter, which can subsequently improve the ecological environment of soils in sloping regions. © 2018 Science Press. All rights reserved.  相似文献   
803.
论环境资源产业化   总被引:3,自引:0,他引:3  
由于环境问题的复杂性与弥散性,直接界定其产权并不能真正解决环境质量问题。本文提出了环境资源产业化这种间接解决方法,并对环境资源产业化的具体内容及外部保障政策作了阐述。  相似文献   
804.
ABSTRACT: Institutional innovation is central to many water resource problems. (In this context “institutions” refers to the laws and regulations governing water allocation and use.) Yet, typically, economic analyses treat institutions as exogenous and fixed. Unfortunately, this conventional assumption does not allow economists to address many modern problems. This paper develops an economic framework in which institutions are treated as endogenous. The model accounts for (1) factors that stimulate calls for formal institutional change, (2) the role of interest groups in policymaking, and (3) actual institutional change as it impacts choice domains and thus economic performance. The model is compared to a specific case of change in Colorado's water institutions, namely, instream water rights legislation in the 1970's. The empirical evidence is generally consistent with model hypotheses. The model promises to be useful to scholars and policymakers interested in institutional innovation.  相似文献   
805.
The importance of soil organic carbon (SOC) under forests in the global carbon cycle depends on the stability of the soil carbon and its availability to soil microbial biomass. We investigated the e ects of successive rotations of Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) plantations on the stability of SOC and its availability to microbes by adopting the two-step hydrolysis with H2SO4 and density fractionation. The results showed that successive rotations of Chinese fir decreased the quantity of total SOC, recalcitrant fraction, and carbohydrates in Labile Pool I (LP I), and microbial properties evidently, especially at 0–10 cm horizon. However, cellulose included in Labile Pool II (LP II) and the cellulose/total carbohydrates ratio increased in successive rotations of Chinese fir. The noncellulose of carbohydrates included in LP I maybe highly available to soil microbial biomass. Hence the availability of SOC to microbial biomass declined over the successive rotations. Although there was no significant change in recalcitrance of SOC over the successive rotations of Chinese fir, the percentage of heavy fraction to total SOC increased, suggesting that the degree of physical protection for SOC increased and SOC became more stable over the successive rotations. The degradation of SOC quality in successive rotation soils may be attributed to worse environmental conditions resulted from disturbance that related to “slash and burn” site preparation. Being highly correlated with soil microbial properties, the cellulose/total carbohydrates ratio as an e ective indicator of changes in availability of SOC to microbial biomass brought by management practices in forest soils.  相似文献   
806.
EG填充无卤阻燃型LDPE复合薄膜阻燃性能研究   总被引:1,自引:0,他引:1  
为了改善聚合物低密度聚乙烯(LDPE)薄膜的阻燃性能,通过向其中添加膨胀型阻燃剂聚磷酸铵(APP)/季戊四醇(PER)和可膨胀石墨(EG),制备了无卤阻燃型低密度聚乙烯复合薄膜.实验研究了膨胀阻燃剂填充聚合物LDPE作为阻燃复合薄膜的性能,分析了膨胀阻燃剂的加入对复合膜阻燃性能、残重率和力学性能的影响机理.研究发现,该新型配方中的EG和APP/PER对复合薄膜的阻燃性能具有协同作用,当配方中APP/PER/EG的填充量达到30%质量分数(APP∶PER∶EG∶LDPE质量比16∶8∶6∶100)时,薄膜材料的氧指数可达到27.5%;与纯LDPE薄膜相比,阻燃薄膜的氧指数提高了10.3%,改善了阻燃效果.  相似文献   
807.
环境知识产权是一种可延续的有期限群体性权利。通过对环境知识产权的定义、特性的阐述,阐明环境知识产权的必然性与可行性,进而通过构建环境知识产权,以期更好地推进环保工作进程。  相似文献   
808.
• CeO2 doping significantly improved low-temperature NH3-SCR activity on FeTiOx. • The crystallinity of FeTiOx was decreased dramatically after CeO2 doping. • Unique Ce-O-Fe structure in FeCe0.2TiOx accounted for its superior redox property. • Facile activation of NH3 to-NH2 on FeCe0.2TiOx promoted the DeNOx efficiency. FeTiOx has been recognized as an environmental-friendly and cost-effective catalyst for selective catalytic reduction (SCR) of NOx with NH3. Aimed at further improving the low-temperature DeNOx efficiency of FeTiOx catalyst, a simple strategy of CeO2 doping was proposed. The low-temperature (<250℃) NH3-SCR activity of FeTiOx catalyst could be dramatically enhanced by CeO2 doping, and the optimal composition of the catalyst was confirmed as FeCe0.2TiOx, which performed a NOx conversion of 90% at ca. 200℃. According to X-ray diffraction (XRD), Raman spectra and X-ray absorption fine structure spectroscopy (XAFS) analysis, FeCe0.2TiOx showed low crystallinity, with Fe and Ce species well mixed with each other. Based on the fitting results of extended X-ray absorption fine structure (EXAFS), a unique Ce-O-Fe structure was formed in FeCe0.2TiOx catalyst. The well improved specific surface area and the newly formed Ce-O-Fe structure dramatically contributed to the improvement of the redox property of FeCe0.2TiOx catalyst, which was well confirmed by H2-temperature-programmed reduction (H2-TPR) and in situ XAFS experiments. Such enhanced redox capability could benefit the activation of NO and NH3 at low temperatures for NOx removal. The detailed reaction mechanism study further suggested that the facile oxidative dehydrogenation of NH3 to highly reactive-NH2 played a key role in enhancing the low-temperature NH3-SCR performance of FeCe0.2TiOx catalyst.  相似文献   
809.
借助于现代产权经济学派的产权残缺理论。揭示陕北黄土高原生态环境治理困境的产权残缺及其根源。进而从产权配置的有效性视角,指出理顺国有公共资源产权配置的责权利关系与效率以及对此公共产权资源增值的分享,对于促进该地区生态治理的深入进行与改善是非常必要的。文章还针对该地区生态环境治理中的产权残缺及其低效性进行深刻剖析,并在此基础上提出了该地区生态环境综合治理的政策建议与措施:要明晰陕北黄土高原生态环境治理中的资源产权,建立资源产权明晰的产权有效保护规则,并以水权为例简要分析了其治理效果。  相似文献   
810.
为解决纯水玻璃(WG)凝胶泡沫强度低、泡沫稳定性差易破碎,凝胶固水性差等问题。将保水剂和成膜剂引入WG凝胶泡沫中,对水玻璃凝胶泡沫进行优化设计,最终制备出保水性高、泡沫稳定性高、成膜性好的WG凝胶泡沫。研究结果表明:WG凝胶泡沫材料的最佳复配体系是发泡剂为十二烷基醇醚硫酸酯钠(AES)和十二烷基硫酸钠(SDS)按1∶2比例复配,浓度为0.8%,胶凝剂WG浓度为8%,交联剂NaHCO3浓度为2%,聚丙烯酰胺浓度为0.4%,成膜剂A浓度为1%,保水剂B浓度为0.3%;改性后WG凝胶泡沫具有更加紧密的网状结构,稳定性好,并且具有较好的成膜性,常温下半衰期达40 d;阻化实验表明,100 ℃此凝胶泡沫阻化率高达78.35%,能有效减缓煤的氧化放热速率抑制自燃;煤堆燃烧实验表明,改性后WG凝胶泡沫能有效抑制煤的燃烧,防止煤复燃。  相似文献   
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