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161.
Deng Y Besse-Hoggan P Husson P Sancelme M Delort AM Stepnowski P Paszkiewicz M Gołębiowski M Costa Gomes MF 《Chemosphere》2012,89(3):327-333
Several physico-chemical properties relevant to determine the environmental impact of ionic liquids - aqueous solubility, octanol/water partition coefficient, chromatographically derived lipophilicity and infinite dilution diffusion coefficients in water - were measured in ionic liquids based on pyridinium, ammonium and pyrrolidinium cations with bis(trifluoromethylsulfonyl)imide anions. The influence of the presence of hydroxyl or ester groups in the physico-chemical properties of these liquids was checked. It appeared that the presence of functional oxygenated moieties reduces the lipophilicity of ionic liquids and so decreases the risk of bioaccumulation in environment. 相似文献
162.
163.
以腐殖酸和纳米Fe2O3为对象,着重研究了腐殖酸分子在纳米Fe2O3表面的吸附过程中的疏水效应,借助红外光谱和热重等分析方法研究了腐殖酸吸附前后的疏水性随溶液环境变化的规律。结果表明,当离子强度为0、0.005、0.01和0.05 mol/kg,pH从7变到12时,纳米Fe2O3吸附溶解性腐殖酸分子后形成的复合体的热失重量随着pH的升高先减小后增大。当pH从7升高到10时,亲水性降低,疏水性增强;当pH从10升高到12时,亲水性增强,疏水性降低。当离子强度为0.001 mol/kg,pH从7变到12时,复合体的热失重量随着pH的升高而减小,亲水性降低,疏水性增强。当pH为定值,离子强度变化时,纳米Fe2O3吸附溶解性腐殖酸分子后形成的复合体的热失重量随着离子强度的增加不断变化,曲线呈现出波动趋势,亲、疏水性在交替变化。红外光谱分析结果说明,对纳米Fe2O3吸附溶解性腐殖酸分子后形成的复合体的亲疏水性起主要影响的官能团可能是亲水性的羟基—OH、羰基CO和疏水性的CH2烷烃。 相似文献
164.
长江源和黄河源的大型底栖动物群落特征研究 总被引:2,自引:0,他引:2
本研究于2009年8月和2010年7月对黄河源和长江源的大型底栖动物开展了系统调查。调查期间两区域共鉴定底栖动物66种,隶属于28科57属。其中,环节动物2科5属8种,软体动物2科2属5种,节肢动物23科49属52种,其它动物1科1属1种。长江源大型底栖动物种数、密度、生物量分别为29种、59 ind./m2、00 307 g dry mass/m2;黄河源大型底栖动物种数、密度、生物量分别为48种、369 ind./m2、04 520 g dry mass/m2。长江源动物资源量较低归因于泥沙含量较高和湿地退化。从生态环境的可持续发展角度出发,建设河源区生态屏障尤为重要,这需要实施天然林保护工程,因地制宜开展乔灌草植被建设,防止草地退化和沙化,减缓土壤侵蚀速率,减少河流输沙量,维系河流生态健康。 相似文献
165.
从港口自身发展及港口城市发展的角度出发,重新定义了港口可持续发展能力的外延和内涵,在遵循建立可持续发展指标体系原则的基础上,形成了衡量港口可持续发展能力的评价体系。一方面该体系中指标信息的可操作性和实用性较强,数据客观真实;另一方面体系中的各类指标能够描述出评价对象的真实状况,且具有横向比较多个评价对象能力的作用。在该评价体系的基础上选取了长江三角洲港口群内的13个港口,采用聚类分析的方法,评价分析了各港口的可持续发展能力。研究结果表明,在该区域内,上海港和宁波-舟山港为第一类,凭借各自的区位条件和经济发展优势,可持续发展能力相对最高;苏州港、连云港港是第二类港口,具有不同的发展优势,可持续发展能力相对较强;其余9个港口中有的虽然在港口建设上具有明显优势,但地区发展相对落后对港口的发展也起到了阻滞作用,总体而言可持续发展能力相对较弱。 相似文献
166.
Bingli Lei Yu Wen Xuetong Wang Jinmiao Zha Wei Li Zijian Wang Yanfeng Sun Jia Kang Yipei Wang 《Chemosphere》2013
The fertilized eggs of Japanese medaka (Oryzias latipes) were exposed to estrone (E1) at 5–5000 ng L−1 for 15 d, and the hatched fry were exposed continuously to the same concentrations for the additional 15 d. Adverse effects on hatchability, time to hatching, and gross abnormalities occurred at 50 ng L−1 or above. Then the fry were divided into a continual exposure group, and a water recovery group. When the fry were exposed to E1 for another 60 d, there was a decrease in the hepatosomatic index (HSI) of males and the influence disappeared in the water recovery group. The gonadosonatic index (GSI) of females at 500 ng L−1 decreased significantly in another 60 d exposure. While the fry were maintained in dechlorinated tap water for 60 d, a significant decrease in female GSI was observed at 50 ng L−1 or above. An increased GSI was found in males in both continual exposure and water recovery groups at all E1 treatments. Quantitative RT-PCR showed that vitellogenin-I (Vtg-I) gene expressions in the female liver were significantly down-regulated at 50 ng L−1 in the continual exposure group, and at 500 ng L−1 in the water recovery group, while male Vtg-I genes were significantly up-regulated for all E1 treatments. In addition, all E1 treatments caused sex reversal of males. These results suggest that E1 at 5 ng L−1 or above have unrecoverable impacts on the gonadal growth and development of medaka, even if only early life stages were exposed to E1. 相似文献
167.
168.
根瘤菌新类群的全细胞蛋白电泳及16S rDNA全序列分析 总被引:15,自引:3,他引:12
应用SDS全细胞蛋白电泳技术对根瘤菌3个新类群进行聚类分析,并对3个新类群中心菌株的16S rDNA全序列(Mr≈1.5kb)进行了测定。将所测序列与EMBL/BankIT/DDBJ资料库中根瘤菌及相关菌已知种的16S rDNA全序列进行聚类比较,得到系统发育树状图,树状图中,菌株SH22623和SH19312与山羊豆根瘤菌、葡萄土壤杆菌、根癌土壤杆菌和悬钩子土壤杆菌在同一个分支上,彼此亲缘关系较 相似文献
169.
云南,西藏热泉中主要微生物类群及其金成矿作用的研究 总被引:2,自引:0,他引:2
从地质微生物生态学的角度研究和阐述了云南和西藏热泉中主要微生物类群及其金成矿作用.发现了热泉中存在的嗜热好氧菌优势菌属为并孢杆菌(Racillus),放线菌中的优势菌属为链霉菌(Streptomyces),真菌中优势菌属为曲霉(Aspergillus),厌氧菌中优势菌为硫酸盐还原菌的脱硫肠状菌属(Desulfotomaculum)和核状芽孢杆菌属(Clostridium),对吸附聚金、沉淀金的功能菌进行的研究发现.嗜热细菌对溶解金有明显的吸附聚金作用,表明原溶液金大多富集于细胞体;并以芽孢杆菌属K12-1菌株等进行了吸附聚金条件试验. 相似文献
170.
Policies that arise out of conflict or collaboration between specific interest groups and government agencies are often explained
by theoretical constructs that fall under the umbrella of group theory. Triangulation theory is one of these constructs and
serves to explain the mutuality of interests that exist between government agencies and interest groups expressed as points
linking geometric forms. Conflict tends to occur when competing interest groups are excluded from the linkage, in this case
between the opponents and proponents of hormone herbicides in the Tala area in Natal, South Africa. In opposition to the use
of hormone herbicides were vegetable farmers and their supporters: in linked support were agricultural interest groups who
used hormone herbicides, the manufacturers of the herbicides, and the government agency responsible for agriculture. Because
of the influence exerted through mutual support by the proponents of hormone herbicides, the formulation of policy decisions
directed towards the resolution of the conflict was delayed. When the minister of agriculture finally intervened, the policy
decisions were designed to secure the support of those opposing the use of hormone herbicides by introducing issues that cut
across those maintaining the discord. 相似文献