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881.
Although leather has a number of desirable properties such as thermal stability and fire retardancey, in addition to high toughness, it has a few drawbacks such as weight, high water absorption, poor soil and rot resistance, and nonuniformity. If these defects are overcome, leather's usefulness would be further enhanced and its competitive position with respect to synthetics would increase. This study reports the physical and mechanical properties of buffalo leather after chemical graft copolymerization with ethyl acrylate, butyl acrylate, and 2‐ethyl hexyl acrylate using benzoyl peroxide as an initiator. The optimum conditions for grafting (e.g., monomer and initiator concentrations, temperature and time of grafting, and solvent leather ratio) were extensively investigated. The study achieved outstanding properties for buffalo leather in reduction of water uptake after grafting, especially on using 2‐ethyl hexyl acrylate and butyl acrylate monomers. FT‐IR and solid 13C‐NMR for leather before and after grafting confirmed the grafting process.© 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1478–1483, 2003 相似文献
882.
β-环糊精是由7个D-吡喃葡萄糖单元通过α-1,4-糖苷键键连成环的超分子主体分子,“内疏水、外亲水”的独特结构赋予了其优异的分子识别能力;氧化石墨烯类材料凭借其优良特性成为近几年的研究热点。由β-环糊精和氧化石墨烯构筑的超分子杂化体在兼具二者特有性能的基础上又有新功能的引入。本文综述了β-环糊精-氧化石墨烯超分子杂化体的构筑方式,按二者间的连接方式,分别为共价键和非共价键两种连接方式,其中通过共价键连接是目前最主要的构筑方式;此外对β-环糊精-氧化石墨烯超分子杂化体的特征和表征进行了简述。同时对β-环糊精-氧化石墨烯超分子杂化体在水污染处理、电化学检测、药物控释和催化等领域的应用进展进行了综述。最后对该超分子杂化体在构筑和应用上的发展趋势进行了展望。 相似文献
883.
884.
生物流化床预处理黄浦江原水中试研究 总被引:6,自引:0,他引:6
对采用悬浮填料的生物流化床原水预处理技术进行了探讨。分析了自然挂膜条件下的工艺启动过程。在8个工况条件下,流化床对污染物的去除效果。中试运行表明;在温度适谊,停留时间为60min,填料填充率为50%条件下,氨氮平均去除效率达到77.6%。氨氮的比表面去除负荷与温度线性相关。相关系数为0.911;CODMn平均去除率为6.5%。中试装置在温度10.6℃条件下,重启动需要4d,即对污染物有较好的去除效果;由于填料的完全流化,池体内溶解氧传质效率高,出水接近饱和溶解氧;进出水浊度变化不大。填料和池体本身不会积泥,不需反冲洗。 相似文献
885.
通过对福建三钢煤化工有限公司废水处理系统生物脱氮工艺的改造,使出水水质达到国家规定的一级排放标准。同时,对焦化废水处理工艺流程、设备及工艺参数等方面进行了调整和改进,为焦化废水生物脱氮工艺的设计和运行提供了借鉴。 相似文献
886.
887.
Effects of coralline lime on nutrient uptake and yield of field-grown sweet corn and peanuts in Oxidic soils of Western Samoa 总被引:1,自引:0,他引:1
Effects of coralline lime on yield and nutrient uptake by sweet corn (Zea mays saccharata Sturt.) and peanut (Arachis hypogea) were studied at three locations in Western Samoa. Coarse (0-10 mm) coralline material containing 31.1% Ca and 1.67% Mg was used as lime. There were two modes of application: band and broadcast, and three rates: 6, 12 and 18 ton ha–1. In the highest rainfall location, marketable yields were increased by 250% for peanut and 160% for sweet corn by liming at 6 ton ha–1, relative to the unamended control. Peanut yield increases were associated with reduced Mn toxicity and/or with Ca and Mg deficiency. Sweet corn was less susceptible to Mn toxicity, but more responsive to exchangeable Ca. The critical level of exchangeable Ca was found to be about 2.0 cmol(+)kg–1. Applying lime to a band of 0.25-m wide did not reduce yield relative to broadcast. Soil cultivation caused the lime to spread over a wider band, diluting the applied calcium with a larger soil volume, suggesting that less than 6 ton ha–1 broadcast coarse coralline lime could still be adequate for most Samoan soils. 相似文献
888.
刘立群 《自动化与仪器仪表》2014,(6):102-104
针对小型农作物温室环境指标监测的需要,设计实现了农作物温室大棚二氧化碳浓度监测系统。采用STC系列单片机控制,对农作物大棚内二氧化碳浓度进行近距离实时监测,采用TFT彩屏显示实时值和动态曲线,具有阀值调节,超过阀值报警,可实现小型温室农作物的生长环境二氧化碳浓度的实时监控。 相似文献
889.
890.
A water‐developable negative photoresist based on the photocrosslinking of N‐phenylamide groups was prepared by the copolymerization of 4‐styrenesulfonic acid sodium salts (SSS) with N‐phenylmethacrylamide (copolymer A) or p‐hydroxy‐N‐phenylmethacrylamide (copolymer B), and its properties such as solubility changes, photochemical reaction, and photoresist characteristics were studied. The copolymer containing a relatively higher amount of SSS units was soluble in water. Solubility changes of the copolymers in the various buffer solutions of pH 4 ~ 11 and in water upon irradiation were observed by the measurement of insoluble fraction. The copolymers were soluble in water before irradiation, whereas they became insoluble upon irradiation with the UV light of 254 nm. The photochemical reaction of the copolymer studied by the UV and IR absorption spectroscopies indicated that a photo‐Fries rearrangement was favored for copolymer A, whereas a photocrosslinking reaction was predominate for copolymer B. Resist properties of the copolymers were studied by measurement of the normalized thickness and by development of the micropattern. Negative tone images with a resolution of 1 μm were obtained with these materials that have a sensitivity (D) of ~ 1100 mJ/cm2 with an aqueous developing process.© 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1172–1180, 2002 相似文献