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151.
采用静态与动态试验方法,对新型阻垢剂膦酰基羧酸共调聚物抑制碳酸钙垢的性能进行了试验研究。静态试验研究表明,在水温低于60℃,钙硬度为600mg/L(以CaCO3计)的情况下,膦酰基羧酸共调聚物具有良好的阻垢性能,投加量为5mg/L时,阻垢率超过90%;在较高硬度时亦有较好的阻垢效果。动态试验研究表明,成垢溶液添加阻垢剂之后,污垢热阻大为减小,换热表面基本不结垢。因此,膦酰基羧酸共调聚物极适于工业循环冷却水系统的水处理过程。结合垢粒的扫描电镜照片对膦酰基羧酸共调聚物的阻垢机理进行了简要分析。 相似文献
152.
Local‐scale Benefits of River Connectivity Restoration Planning Beyond Jurisdictional Boundaries 下载免费PDF全文
A. W. Milt P. J. Doran M. C. Ferris A. T. Moody T. M. Neeson P. B. McIntyre 《河流研究与利用》2017,33(5):788-795
Conservation planning aims to optimize outcomes for select species or ecosystems by directing resources toward high‐return sites. The possibility that local benefits might be increased by directing resources beyond the focal area is rarely considered. We present a case study of restoring river connectivity for migratory fish of the Great Lakes Basin by removing dams and road crossings within municipal jurisdictions versus their broader watersheds. We found that greater river connectivity could often be achieved by considering both intra‐jurisdictional and extra‐jurisdictional barriers. Focusing on jurisdictional barriers alone generally forfeited <20% (median = 0%) of habitat gains for those who value solely habitat gains within the jurisdiction, but >75% (median = 100%) for planners who value larger‐scale habitat gains. Similarly, cost savings tended to be between ?50% and +50%, but in some cases were very negative. Our study underscores the local‐scale benefits of broadening restoration investments, especially for decision makers of the Great Lakes Basin and contributes to a discussion of appropriate and efficient scales of conservation planning. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
153.
本文介绍了国内外甲醇生产消费情况及生产工艺路线,并对目前普遍应用的ICI低压法和鲁奇低压法进行了综合分析和对比。同时,还就采用ICI工艺或鲁奇工艺建10万吨/年甲醇装置进行了经济分析。 相似文献
154.
用γ-缩水甘油醚氧丙基三甲氧基硅烷(KH560)、1-氯辛烷对低相对分子质量聚乙烯亚胺(PEI)进行疏水接枝改性,得到了含硅疏水改性聚胺阻垢剂。通过FTIR、TG、粒径分析、Zeta电位测试等分析改性后聚胺阻垢剂的结构与性能。结果表明,改性后产物热稳定性提高、黏度增大、表面张力降低、溶液粒径增大。将改性聚胺阻垢剂用于分散铝硅酸钠颗粒,对处理前后的颗粒进行红外光谱表征,并通过对悬浮分散液进行稳定性、颗粒沉降等测试,评价聚胺阻垢剂的阻垢分散性能并初步讨论其分散机理。当m(PEI, M_w=10000)∶m(KH560)∶m(1-氯辛烷)=10∶2∶0.5,反应时间6 h,反应温度75℃时,合成的阻垢剂分散性能最佳。当结疤的质量浓度为30 g/L时,悬浮液颗粒沉降速度达到最低值0.047 cm/d,沉降速率减小程度达到94.8%,分散性显著提高。经过改性后的PEI在氧化铝工业生产中具有高效的阻垢作用,可通过在工厂进行条件优化,进一步替代传统的强酸型阻垢剂,减小管道腐蚀程度,降低能耗。 相似文献
155.
前大油田注水系统防腐防垢技术的研究 总被引:1,自引:0,他引:1
前大油田注水系统腐蚀、结垢问题十分突出,开发了适用于前大油田注水水质的JYSJ-Q型杀菌剂、JYHZJ-Q型缓蚀阻垢剂,并通过试验确定了配套加药工艺.经现场应用,有效缓解了注水系统的腐蚀结垢问题,获得了显著的社会效益及经济效益. 相似文献
156.
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158.
Occurrence patterns of alien freshwater turtles in a large urban pond ‘Archipelago’ (Rome,Italy): Suggesting hypotheses on root causes 下载免费PDF全文
Maria Paola Di Santo Leonardo Vignoli Giuseppe M. Carpaneto Corrado Battisti 《Lakes & Reservoirs: Research and Management》2017,22(1):56-64
The patterns of the occurrence and distribution of alien freshwater turtle species in an urban pond archipelago (Rome, Italy) were analysed, with the aim of exploring the role of a set of factors (type of ponds, landscape context, size area, distance from the nearest road) with a generalized linear model approach. A total of 311 ponds subdivided in three types (fountains, small basins, lakes) embedded in different landscape contexts (public parks, private parks, urban areas) at differing distances from the nearest road were sampled. Six non‐native freshwater turtle species in 31 sites were recorded (9.97%). Lakes exhibited the highest occurrence rates of alien freshwater turtles, compared to small basins and fountains. Freshwater turtle species in urbanized areas were only observed in parks (both public and private). In both the public and private parks, the lakes exhibited the highest percentage of occupied sites, with fountains being the lowest. A direct and significant relationship was observed between pond size and species richness. The distance from the nearest road did not appear to affect species richness. A first interpretation of the data from this study facilitated the postulation of two a posteriori hypotheses that should be tested, as follows: (i) the causal process of turtle release is random, and the rate of extinction (and recapture) is higher in smaller ponds, thus producing the observed pattern; and (ii) the turtle release is not random, and people actively select the ponds they consider more suitable for their pet animals. In this study, it appears the lakes were perceived by those who abandon their pets as the most ecologically suitable habitats among other pond types to accommodate the different species of turtles. Knowledge of people's attitudes in regard to releasing pet animals also might assist managers of public green spaces to develop strategies aimed to preserve local biodiversity, and to educate the public about the conservation issue represented by the alien species. 相似文献
159.
160.
Scale formation has been recognised as a widespread problem in membrane filtration and water desalination processing for water treatment. In this paper, the effect of surface energy of Ni-P-PTFE composite coatings on the microstructure and adhesion of CaSO4 deposits was investigated. The surface energies of the Ni-P-PTFE coatings were altered by changing the PTFE proportion in the coatings. Initial experimental results showed that the surface energy of the coatings had a significant influence on the microstructure and adhesion of CaSO4 deposits. The Ni-P-PTFE coatings have a potential for reducing CaSO4 scale formation on water treatment equipment. 相似文献