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在由鼠李糖脂和Tween-80构建而成的复配逆胶束媒介研究了漆酶的催化性能.采用紫外法考察了Tween-80摩尔含量、逆胶束含水量、水相酸碱度、水相盐度以及助表面活性剂种类等反应条件对漆酶催化性能的影响.研究结果表明,反应的最佳条件:Tween-80的摩尔含量为30%,体系含水量为20,缓冲溶液pH为4.5,KCI浓度为70mmol/L,助表面活性剂正己醇.并且在最佳条件下,漆酶在复配逆胶束体系中的酶活比在单相鼠李糖脂逆胶束中高1.44倍,比在水溶液中高4.35倍,研究结果表明复配表面活性剂在构建胶束酶学上具有很大的潜力. 相似文献
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对一种新型生物表面活性剂逆胶束中漆酶的催化性能进行了研究.以鼠李糖脂(RL,阴离子生物表面活性剂)为表面活性剂,异辛烷和正己醇为溶剂和助表面活性剂,构建逆胶束,分别考察了有机相组成、RL浓度、逆胶束体系含水率W0、缓冲溶液酸碱度及盐浓度等因素对该逆胶束体系中漆酶催化性能的影响.结果表明,当逆胶束有机相正己醇/异辛烷体积比为1:1.8,RL浓度为13mmol/L,体系含水率W0为42,缓冲溶液pH5.0,KCl浓度为10mmol/L时,该体系中漆酶具有较好的活性及稳定性.对比试验显示,与化学表面活性剂AOT逆胶束相比,RL逆胶束能使漆酶表现出较高的活性及稳定性,说明与传统化学表面活性剂相比生物表面活性剂在构建逆胶束酶体系上的具有一定的优越性. 相似文献
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采用人工配水和市政污水研究了“缺氧-厌氧-好氧”(倒置AAO)脱氮除磷工艺中,聚磷微生物(PAOs)在低碳源、高硝酸盐环境下的释磷和吸磷行为.结果表明,在低碳源、高氮和磷环境中,尽管PAOs在缺氧厌氧段释磷程度低,如果适当延长厌氧段和好氧段的HRT、且好氧曝气较充分,仍能超量吸收磷.PAOs过量吸磷的能量来源不仅仅是厌氧段吸收与合成的胞内聚合物在好氧段的氧化,还来自好氧环境正常代谢过程中多余的能量.外加碳源的投加时间点对PAOs吸磷的影响不显著.PAOs在厌氧段后期出现过量吸磷现象,推测是细胞内有机物厌氧降解产生的ATP通过某种代谢途径被用于无机磷的吸收. 相似文献
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为了研究口服化学战剂降解产物二苯胂酸(DPA)导致小脑功能异常与诱发小鼠小脑蒲肯野细胞氧化和氮化应激之间的关系,利用硫代巴比妥酸反应物(TBARS)法和免疫组织化学方法检测脑组织丙二醛(MDA)和3-硝基酪氨酸(3-NT)的变化情况.同时,通过在体外合成3价DPA的模型化合物二苯胂酸碘(DPI),并用Western-blot检测3-NT的生成.研究发现,在小鼠一次口服15mg·kg-1DPA以及连续5d口服5mg·kg-1 DPA的情况下,小脑组织TBARS上升,蒲肯野细胞MDA和3-NT染色阳性.体外实验检测到DPI和NO反应可以生成3-NT,这表明DPA会导致小鼠小脑功能异常,这与其在体内代谢过程中产生的砷相关活性物质在小脑蒲肯野细胞诱发氧化和氮化应激密切有关. 相似文献
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Occurrence, polarity and bioavailability of dissolved organic matter in the Huangpu River, China 总被引:4,自引:0,他引:4
Qianqian Dong Penghui Li Qinghui Huang Ahmed A. Abdelhafez Ling Chen 《环境科学学报(英文版)》2014,26(9):1843-1850
Dissolved organic matter (DOM) plays an important role in biogeochemical cycles in aquatic ecosystem. To investigate the characteristics of DOM in Huangpu River {the last tributary of the Yangtze River), surface water samples were collected along the river from December 2011 to June, 2013. The concentrations of dissolved organic carbon (DOC), the absorbance and fluorescence spectrum of DOM in water samples were measured. Fluorescent DOM in the Huangpu River was decomposed into four components by the parallel factor analysis (PARAFAC), including one humic-like substance and three protein-like substances. It showed that high spatial variability of DOC concentration was observed in the upstream water compared to the downstream water, and so did the absorbance coefficients of chromophoric dissolved organic matter and the total fluorescence intensities of different PARAFAC components of DOM. Furthermore, there was a large difference between the polarity and bioavailability of DOM in the Huangpu River. Polar compounds dominated tyrosine-like component of fluorescent DOM in all seasons. Tryptophan-like and humic-like substances had more polar fraction in summer and autumn than those in winter, while aromatic protein-like materials had the highest polar fraction in winter. Almost all of fluorescent DOM components were refractory in spring, while less than 20% of fluorescent DOM in average were biodegradable within 4 weeks in other seasons. We concluded that the spatial variation in the abundance of DOM in the Huangpu River is mainly affected by the water discharges from the Hangjiahu Plain and the seasonal difference in polarity and bioavailability of DOM is largely determined by its origins. 相似文献
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基于Gompertz模型预测中国2018~2050年民用汽车的社会保有量;在此基础上,采用物质流分析方法估算得出我国汽车高峰报废年限大约为9a.然后,通过市场供给A模型预测我国2018~2025年汽车报废量,结果显示,我国汽车报废量到2025年将达到2535.05万辆,并且地理空间分布极不均衡.基于上述汽车报废量的时空分布,测算不同技术发展情景下废汽车三元催化剂中的铂族金属回收潜力和需求量.结果显示:如果按照当前催化剂消耗水平,全国铂族金属的需求量均在2019年达到峰值,铂钯铑分别达到4.57,65.70,7.92t,有望实现行业内闭环供应;如果以欧盟汽车尾气治理标准为目标,而现有汽车技术不发生根本变化,需求量将大幅增加,铂钯铑分别在2020年达到峰值85.01,109.38,8.37t,存在严重的供需矛盾.为此,建议在汽车生产者责任延伸制度中,关注废催化剂的回收和再生利用,以促进前端生产环节在不同技术选择中考虑稀贵金属的供给限制. 相似文献
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基于Gompertz模型预测中国2018~2050年民用汽车的社会保有量;在此基础上,采用物质流分析方法估算得出我国汽车高峰报废年限大约为9a.然后,通过市场供给A模型预测我国2018~2025年汽车报废量,结果显示,我国汽车报废量到2025年将达到2535.05万辆,并且地理空间分布极不均衡.基于上述汽车报废量的时空分布,测算不同技术发展情景下废汽车三元催化剂中的铂族金属回收潜力和需求量.结果显示:如果按照当前催化剂消耗水平,全国铂族金属的需求量均在2019年达到峰值,铂钯铑分别达到4.57,65.70,7.92t,有望实现行业内闭环供应;如果以欧盟汽车尾气治理标准为目标,而现有汽车技术不发生根本变化,需求量将大幅增加,铂钯铑分别在2020年达到峰值85.01,109.38,8.37t,存在严重的供需矛盾.为此,建议在汽车生产者责任延伸制度中,关注废催化剂的回收和再生利用,以促进前端生产环节在不同技术选择中考虑稀贵金属的供给限制. 相似文献
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The use of chemical signals in a sexual context is widespread in the animal kingdom. Most studies in spiders report the use of female pheromones that attract potential sexual partners. Allocosa brasiliensis and Allocosa alticeps are two burrowing wolf spiders that show sex-role reversal. Females locate male burrows and initiate courtship before males perform any detectable visual or vibratory signal. So, females of these species would be detecting chemical or mechanical cues left by males. Our objective was to explore the potential for male pheromones to play a role in mate detection in A. brasiliensis and A. alticeps. We designed two experiments. In Experiment 1, we tested the occurrence of male contact pheromones by evaluating female courtship when exposed to empty burrows constructed by males or females (control). In Experiment 2, we tested the existence of male volatile pheromones by evaluating female behaviour when exposed to artificial burrows connected to tubes containing males, females or empty tubes (control). Our results suggest the occurrence of male volatile pheromones that trigger female courtship in both Allocosa species. The sex-role reversal postulated for these wolf spiders could be driving the consequent reversal in typical pheromone-emitter and detector roles expected for spiders. 相似文献
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落实《水污染防治行动计划》投融资思路与建议——对《水污染防治行动计划》的解读 总被引:1,自引:0,他引:1
创新、拓宽水环境保护领域投融资渠道,是落实水污染防治行动计划、保障国家水安全的关键环节。研究结论表明,水污染防治领域成熟稳定的财政资金投入机制匮乏、中小环保企业水环境治理项目融资存在制约瓶颈、社会资本水污染治理投入盈利机制不健全等是关键制约因素。鉴于此,文章提出了落实《水污染防治行动计划》的投融资思路和具体建议:整合设立水污染防治专项资金以建立政府常态化投入机制,设立政府主导的环境保护基金以发挥财政资金引导作用,建立社会资本水污染防治项目资金投入回报机制以吸引社会资本投入,创新环境金融服务、发挥市场融资作用以提升水污染治理企业或项目融资能力。 相似文献
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对中国典型社会源危险废物的潜在资源量进行了预测与估算.在界定社会源危险废物概念和构建其物质代谢模型的基础上,根据GM(1,1)灰色预测模型及Weibull寿命分布模型,利用2006~2015年中国典型社会源危险废物原产品消费的时间序列样本数据,模拟了其消费量和报废量的动态变化趋势,进一步建立了潜在资源量预测模型并分析了潜在资源的再利用价值.据预测,2025年中国将产生废旧铅酸电池4.16亿kW·h、节能灯6.34亿支和线路板1.09亿m2,可回收的资源总量达1200万t以上,包括贵金属0.15万t、具有环境危害性的重金属368万t和其它可回收资源879万t. 相似文献