114 research outputs found

    Determination of bisphenol A in environmental water samples by stir bar sorptive extraction based on molecularly imprinted polymer

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    以双酚A(bPA)为单体,利用整体材料“原位“聚合技术制备以分子印迹聚合物为涂层的吸附萃取搅拌棒(MIP-SbSE),然后与高效液相色谱(HPlC)-二极管阵列检测器联用,探讨其对环境水样bPA的选择萃取性能。优化萃取过程中吸附和解吸时间、解吸液种类以及基底PH值和离子强度对目标化合物的选择吸附性能。在最佳条件下,MIP-SbSE可对模板分子进行有效的选择吸附,线性范围为1.0~200μg/l,检出限(S/n=3)和定量限(S/n=10)分别为0.28μg/l和0.94μg/l。在实际水样分析中,具有良好的加标回收率,其值为96.0%~108.7%。研究结果表明,所建立的方法具有简便、灵敏和环境友好等特点。A new stir bar sorptive extraction (SBSE) based on molecularly imprinted polymer (MIP) with bisphenol A as template was prepared.Based on it,a simple,selective and sensitive method for the determination of bisphenol A (BPA) was developed combined with high performance liquid chromatography (HPLC) with diode array detection.To achieve the optimum extraction performance,several main parameters,including extraction and desorption time,the nature of desorption solvent,pH value and contents of inorganic salt in the sample matrix,were investigated.The optimized parameters for the extraction of BPA from water matrix with the MIP-SBSE are as follows: extraction and desorption time were 120 min and 10 min,respectively; the pH value of matrix was 10.0; using acetonitrile (including 1% acetic acid) as desorption solvent; no salt was added in the matrix.Under the optimized experimental conditions,the method showed good linearity between 1.0-200 μg/L.The detection limit (S/N=3) and quantification limit (S/N=10) of the proposed method for the BPA was 0.28 μg/L and 0.94 μg/L,respectively.The proposed method was successfully applied to the determination of the target compound in water samples.The recoveries of spiked target compound in real samples ranged from 96.0%-108.7%.The results indicated that the developed method possessed the advantages such as high sensitivity,simplicity,low cost and environmental friendliness.国家自然科学基金项目(No.20805039);福建省青年科技人才创新项目(No.2006F3117

    Expression of recombinant hARRG cDNA in E.coli and purification of hARRG protein

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    目的 构建含重组人类抗砷相关基因 (humanarsenicresistencerelatedgene ,hARRG)的表达载体 ,诱导其在转化菌表达 ,分离纯化表达蛋白 ,研究该蛋白质的理化性质、抗砷功能和免疫活性 ,深入研究人类对砷化物的抵抗作用。方法 将hARRGcDNA开放阅读框亚克隆到原核表达载体Pet11C中 ,用异丙基 - β -D -硫代半乳糖苷 (IPTG)诱导表达蛋白质 ,利用阴离子交换柱Sepharose纯化蛋白质 ,SDS -PAGE胶电泳观察结果。 结果 将hARRGcDNA成功亚克隆到原核表达载体Pet11C中 ,并成功在大肠杆菌中表达 ,表达的hARRG蛋白占菌体蛋白的 5 %左右 ,该蛋白质被分离纯化。结论 原核表达载体Pet11C可以在大肠杆菌中表达hARRGcDNA ,可用阴离子交换柱Sepharose纯化抗砷相关蛋白质Objective To construct expression vector of the recombinant human arsenic resistance related gene (hARRG),induce its expression in DE\-3 and isolate and purify expression product,for studying the physiochemistry characteristic,function and immune activity of the protein,and further researching the arsenic resistant effects of human.Methods hARRG cDNA was subcloned into prokaryotic expression vector Pet11C.The recombinant protein expression was induced by IPTG,then,the protein was purified by anions Ion-exchange column Sepharose and examined by SDS-PAGE gel.Results hARRG cDNA was successfully subcloned into prokaryotic expression vector Pet11C and expressed in E.coli and the protein was purified by anions Ion-exchange column successfully.Conclusion Pet11C excpression vector containing hARRG cDNA wassuccessfully constructed,the cell DE\-3 transformed with expression vector capable of expression the gene and a hARRG protein could be purified by anions Ion-exchange column Sepharose.国家自然科学基金资助项目 (30 0 60 0 74

    Effect of Flue-gas Cleaning Devices on Mercury Emission From Coal-fired Boiler

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    为研究燃煤锅炉烟气净化设施对汞排放特性的影响,采用Ontario-Hydro方法,对设有催化脱硝、静电除尘、海水脱硫的300MW燃煤锅炉排放烟气中汞的含量与形态进行分析,同时测定锅炉的煤、底渣、飞灰等固体样品以及脱硫塔前后、曝气之后海水样品中的汞含量。实验结果为:烟气中的气态汞占总汞的79.1%以上,脱硝催化剂对汞的价态具有强烈的转化作用,烟气中83.4%的气态Hg0被氧化成气态Hg2+;静电除尘对颗粒态汞的去除率几乎达到100%;在脱硫塔中,海水对烟气中汞的洗脱率高达73.6%,曝气后排放前的海水中含汞量是新鲜海水的5.5倍。研究表明锅炉烟气净化设施对汞的排放特性有着重要的影响。In order to study the effect of flue-gas cleaning devices on mercury emission from coal-fired boiler, Ontario-Hydro method had been applied to determine the mercury concentration and speciation in the flue-gas emitted from a 300MW coal-fired boiler, which was equipped with various pollution control devices, including selective catalyst reduction (SCR) De-NOx system, electrostatic precipitator (ESP), and flue-gas seawater De-SO2 system (FGD). Mercury concentration in raw coal, bottom ash and fly ash of the boiler, seawater at the inlet and outlet of SO2 absorption reactor and the drainage of aeration sink, were also analyzed. The results indicate that the percentage of gaseous mercury in total mercury discharged is more than 79.1%. De-NOx catalyst strongly affects the mercury speciation transformation, showing a conversion rate of 83.4% for Hg0 to Hg2+. The removal efficiency of particulate mercury by ESP is close to 100%. With seawater FGD, the removal efficiency of mercury is as high as 73.6%. The mercury concentration in the seawater of drainage from aeration sink is 5.5 times higher than that in fresh seawater. The study shows that the flue-gas cleaning devices in coal-fired power plant play an important role on mercury emission characterization

    Some Effects of Co on the Electrochromic Properties of NiO xH y Film

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    本文利用阴极化电沉积法在抛光镍板及ITO玻璃表面制备了含Co量为16.2%的NiOxHy薄膜,薄膜厚度分别为42nm、21nm,采用透射光谱以及线性电位扫描、交流阻抗和阳极稳态极化曲线等测试技术,考察了Co对NiOxHy薄膜电致变色性能的影响,光谱测试范围为300~2500nm.结果发现:Co能降低薄膜着色态在可见光区及部分近红外区的透过率,通过电压调节不仅可以调光而且可望能够控温;同时Co还能降低NiOxHy薄膜电致变色电位,升高薄膜氧化着色过程中的氧析出过电位,对薄膜的电致变色性能有改进作用,但降低了着色过程中质子的扩散系数.Some effects of Co addition upon the electrochromic characteristics of a nic_kel hydroxide film were studied. The films were electrodeposited on both polished Ni plate and conductive ITO glass. The electrochemical behaviors were investigated using the film on Ni plate by linear potential sweep, a.c. impedance, and anodic polarization curves for OER(oxygen evolution reaction). It was found that Co can lower the working voltage and raise the oxygen overpotential, but has little effect on the reaction kinetics. It was also found that the Co can improve the optical properties of the electrochromic film.作者联系地址:南开大学新能源材料化学研究所Author's Address: Inst. of New Energy Material Chem. Nankai Univ., Tianjin 30007

    Residents Housing Mortgage Loans,Housing Demand,Houseing Price and Economic Fluctuation:A Study Based on Bayesian DSGE

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    本文借鉴信贷配给理论及观点,并将个人房产抵押贷款特征和宏观经济联动引入dSgE模型,模型根据我国1999—2013年真实经济数据校准并采用贝叶斯估计方法,对模型进行模拟和脉冲相应方差分解分析,实证验证了居民房产抵押贷款与宏观经济波动之间的传导机制及联动关系,并进一步佐证我国近年来居民房产需求造成房地产投资过热,房价居高不下的事实,这为我国今后采取相关政策和及时疏通房产抵押贷款与宏观经济影响房价、投资及消费的传导机制提供了一定的参考。Based on the theory of credit rationing and the viewpoint,innovation of personal property mortgage characteristics and macroeconomic linkage are introduced into the DSGE model.According to the real economy in China from 1999 to 2013data calibration and the Bayesian estimation method,the paper made an analysis of simulate and impulse response variance decomposition.The empirical results show that the model can fit the reality of China's economy,and empirically verify the conduction mechanism and the linkage between residents mortgage loans and macroeconomic fluctuation,and further prove China's residential property demand in recent years caused by the overheated real estate investment,housing prices high fact.It provides scientific support for future of China's adopting policies,investment and consumption of real estate mortgage loans

    40 Gbit/s WDM系统在长途骨干网中的应用

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    随着业务的爆炸式增长,40 Gbit/s WDM(波分复用)系统已经在现有骨干网中大规模商用。文章分析了40 Gbit/s系统工程建设中的相关问题,包括40 Gbit/s系统的光纤选型、编码选择、40 Gbit/s系统中10 Gbit/s业务的解决方案、40 Gbit/s系统的OLP(光线路保护)和客户端解决方案

    Mapping the trends and knowledge of research using the SWAT model of agricultural non-point source pollution

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    农业非点源污染已成为全球重要的环境问题,模型是当前非点源污染研究的核心内容.为全面了解农业非点源污染SWAT(Soil and Water Assessment Tool)模型研究概况,并获得学科发展趋势、研究力量与研究热点,利用引文分析工具进行数据挖掘与科学知识图谱呈现.自1994年第1篇SWAT模型研究论文发表以来,论文数量呈逐年上升趋势:美国处于绝对领先的地位;中国发文量407篇,排名第2位,其中中国科学院与北京师范大学研究表现突出.研究热点主要集中在SWAT模型特点、模型演化、运算法则以及在农业非点源污染方面的应用.SWAT模型应用于国外各大流域以及我国众多流域研究.SWAT模型在农业非点源污染、泥沙产量、农药输移等方面研究得到了大量应用.未来我国应积极开展SWAT模型基础研究,并开发出适用于我国各地河流水域特点的组件,为流域管理与污染控制提供有效决策支撑与科学依据

    抗对虾白斑综合症病毒单链抗体P1D3基因在毕赤酵母中的分泌表达

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    为了将可中和对虾白斑综合症病毒(WSSV)的单链抗体P1D3在酵母中实现表达,以原核表达载体M13噬菌粒为模板,设计带有SnaBⅠ和EcoRⅠ酶切位点的特异性引物,通过PCR方法扩增P1D3基因。经过酶切、连接反应将该基因连入大肠杆菌-酵母穿梭质粒pPIC9K上。重组质粒pPIC9K-scFvP1D3经BglⅡ线性化后,用电转化的方法转入毕赤酵母(Pichiapastoris)GS115中。通过PCR和DNA测序,挑选和鉴定阳性克隆。经甲醇诱导,P1D3在酵母中获得分泌表达。ELISA实验结果表明,酵母

    抗对虾白斑综合症病毒单链抗体P1D3基因在毕赤酵母中的分泌表达

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    为了将可中和对虾白斑综合症病毒(WSSV)的单链抗体P1D3在酵母中实现表达,以原核表达载体M13噬菌粒为模板,设计带有SnaBⅠ和EcoRⅠ酶切位点的特异性引物,通过PCR方法扩增P1D3基因。经过酶切、连接反应将该基因连入大肠杆菌-酵母穿梭质粒pPIC9K上。重组质粒pPIC9K-scFvP1D3经BglⅡ线性化后,用电转化的方法转入毕赤酵母(Pichiapastoris)GS115中。通过PCR和DNA测序,挑选和鉴定阳性克隆。经甲醇诱导,P1D3在酵母中获得分泌表达。ELISA实验结果表明,酵母
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