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佛甲草用于屋顶绿化--绿色建筑新技术 总被引:5,自引:0,他引:5
针对以往屋顶绿化存在的问题,提出新的解决方法和技术,说明其技术特点、经济效益、环保节能的效果及对建筑和城市的作用. 相似文献
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Pot experiments were conducted to investigate the changes of the dissolved organic matter (DOM) in the rhizosphere of hyperaccumulating ecotype (HE) and non-hyperaccumulating ecotype (NHE) of Sedum alfredii and its effects on Zn and Cd sorption by soils. After planted with HE, soil pH in the rhizosphere reduced by 0.5-0.6 units which is consistent with the increase of DOM. The hydrophilic fractions (51%) in DOM from the rhizosphere of HE (HE-DOM) was much greater than NHE-DOM (35%). In the presence of HE-DOM, Zn and Cd sorption capacity decreased markedly in the following order: calcareous clay loam > neutral clay loam > acidic silty clay. The sorption isotherms could be well described by the Freundlich equation (R2 > 0.95), and the partition coefficient (K) in the presence of HE-DOM was decreased by 30.7-68.8% for Zn and 20.3-59.2% for Cd, as compared to NHE-DOM. An increase in HE-DOM concentration significantly reduced the sorption and increased the desorption of Zn and Cd by three soils. DOM derived from the rhizosphere of the hyperaccumulating ecotype of S. alfredii could significantly reduce metal sorption and increase its mobility through the formation of soluble DOM-metal complexes. 相似文献
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Leaching of heavy metals from Sedum alfredii Hance biomass was studied with ammonia-ammonium chloride solution as leaching agent. The research was carried out in two phases: 1) a leaching study to determine the zinc extraction efficiency of this leaching agent, and 2) a thermodynamic analysis to identify the likely reactions and stable Zn(II) species formed in the leaching systems. Taguchi orthogonal experiment, with four variable parameters, leaching temperature, molar ratio of NH4Cl to NH3, leaching time and solid-to-liquid(L/S) ratio, and each at three levels, was used to optimize the experiment parameters by the analysis of variances. The results indicate that leaching temperature has the most dominant effect on metal extraction performance, followed by molar ratio of NH4Cl to NH3, solid-to-liquid ratio and leaching time. The optimum condition was obtained as follows: temperature of 60°C, molecular ratio of NH4Cl to NH3 of 0.6, leaching time of 2 h and solid-to-liquid ratio of 5:1. The total zinc leaching efficiency under optimum conditions reaches 97.95%. The thermodynamic study indicates that the dominant species produced by the leaching process should be the soluble Zn(NH3)42+. 相似文献
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A field study to evaluate runoff quality from green roofs 总被引:6,自引:0,他引:6
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[目的]室内测定了八宝景天乙醇提取物对菜青虫3龄幼虫的拒食和触杀作用。[方法]采用小叶碟法和浸渍法分别测定乙醇提取物对菜青虫的拒食和触杀作用。[结果]浸渍法处理对菜青虫3龄幼虫48、72 h的致死中浓度(LC50)分别为7.768、0.183 g/L,且校正死亡率均达100%,24、48 h的拒食率最高分别为99.15%、91.94%,拒食中浓度(AFC50)分别为4.819、15.442 g/L。[结论]八宝景天乙醇提取物对菜青虫3龄幼虫具有较高的拒食和触杀活性,为生物源农药提供了一种新的植物来源。 相似文献
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本文以费菜为研究对象,采用不同浓度5、10、20、30、40 mmol/L蔗糖培养液对费菜嫩枝进行培养,选取费菜黄酮含量富集作用较强的蔗糖培养液,并研究该浓度下费菜的抗氧化性。结果表明:选取20 mmol/L蔗糖培养液对费菜培养,对黄酮有较好的富集作用,该浓度培养液的费菜黄酮含量(鲜重)平均值为对照组的1.58倍;蔗糖处理明显提升了费菜DPPH自由基清除能力及总酚的含量;与对照组相比,蔗糖处理组苯丙氨酸解氨酶(phenylalanine ammonialyas,PAL)酶活力也一直保持较高水平;超氧化物歧化酶(superoxide dismutase,SOD)、抗坏血酸过氧化物酶(ascorbate peroxidase,APX)、过氧化物酶(peroxidase,POD)等抗氧化酶活力在外源蔗糖的影响下均高于对照组。这些结果表明了外源蔗糖处理较好地提高了费菜黄酮含量和抗氧化性,为费菜黄酮的富集提供了新的思路和理论依据。 相似文献