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Fractionation of residual Al in natural water treatment from reservoir with poly-aluminum-silicate-chloride (PASiC): Effect of OH/Al, Si/Al molar ratios and initial pH

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Journal of Environmental Sciences 2012年第11期24卷 1908-1916页

作者： Zhonglian Yang Baoyu Gao Yan Wang yaqin zhao Qinyan Yue Shandong Key Laboratory of Water Pollution Control and Resource Reuse School of Environmental Science and EngineeringShandong UniversityJi'nan 250100China

An aluminum fractionation study was conducted for a surface reservoir water treatment to understand the performance of poly- aluminum-silicate-chloride （PASiC） in terms of the residual A1 fractions as a function of initial pH. The coagulation performance expressed as turbidity and organic matter removal was established as supporting data. Some extra data were evaluated in terms of the residual A1 ratio of the composite PASiC coagulant. The main residual A1 sources were the A1 fractions derived from the use of PASiC. The turbidity and organic matter removal ability was optimal at initial pH 6.00-7.00, while the concentrations of various residual A1 species and the residual A1 ratio of PASiC were minimal at an initial pH range of 7.00-8.00. Under the conditions of OH/AI molar ratio = 2.00 and Si/A1 molar ratio = 0.05, PASiC had superior coagulation performance and comparatively low residual A1 concentrations. The A1 fraction in the composite PASiC coagulant seldom remained under such conditions. Experimental data also indicated that the suspended （filterable） AI fraction was the dominant species, and organic-bound or organo-A1 complex A1 was considered to be the major species of dissolved A1 in water treated by PASiC coagulation. Additionally, the dissolved inorganic monomeric A1 species dominated the dissolved monomeric A1 fraction.

关键词： coagulation performance OH/A1 and Si/AI molar ratio poly-aluminum-silicate-chloride (PAniC) resi0ual AI speclataon residual A1 ratio

Fluorescence study on the interaction between apoCopC and cupric

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Chinese Science Bulletin 2005年第20期50卷 2302-2305页

作者： PANG Erguo zhao yaqin YANG Binsheng Institute of Molecular Science Chemical Biology and Molecular Engineering Laboratory of Ministry of Education Shanxi University Taiyuan 030006 China

The interaction between apoCopC and cupric was investigated by fluorescence spectra, in phosphate (20 mmol/L) buffer at pH 6.0. Results suggest that the environ- ment is measured to be hydrophobic completely around tryptophan (83). At the same time, apoCopC fluorescence at 320 nm was significantly quenched with the addition of cu- pric and the 1:1 stoichiometric ratio of apoCopC to cupric was confirmed by fluorescence. In addition, the conditional binding constants were calculated to be KCu-Copc = (1.8±0.58)× 1013 mol?1 L on the basis of the results of fluorescence titra- tion curves. The apoCopC has the ability to bind specifically cupric ion.

关键词： apoCopC 荧光性交互作用二价铜光谱

Properties of Molten Potassium Niobate System

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Chinese Physics Letters 1995年第2期12卷 83-86页

作者： HONG Xinguo LU Kunquan zhao yaqin WU Xing Institute of Physics Academia SinicaBeijing 100080

The density and surface tension of the K_(2)O-Nb_(2)O_(5) molten system between 50 and 56mol%K_(2)O melts were measured from 1080 to 1180℃.The concentration of K_(2)O from 50 to 56mol%in melt not only caused the density of melt to decrease,but also induced the surface tension to *** composition gradient and the temperature coefficient of density exist extremum within this composition *** properties are possibly employed to explain why the KNbO3 crystal should be grown at the composition from 52 to 54mo1%K_(2)O at above 1150℃.

关键词： tension surface coefficient

Binding of Euplotes octocarinatus centrin with target peptide melittin

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Chinese Science Bulletin 2007年第23期52卷 3216-3220页

作者： zhao yaqin FENG JiuYing LIANG AiHua YANG BinSheng Institute of Molecular Science Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education Shanxi University Taiyuan 030006 China Institute of Biotechnology Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education Shanxi University Taiyuan 030006 China

Interactions between model target peptide melittin (ME) and Euplotes octocarinatus centrin (EoCen) were investigated by fluorescence spectra, circular dichroism (CD) spectra and native polyacrylamide gel electrophoresis (PAGE). In 0.1 mol/L N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid (Hepes) and 150 mmol/L NaCl at pH 7.4, EoCen and isolated short C-terminal domain of EoCen (SC-EoCen) form 1:1 peptide:protein complexes. However, no detectable signal changes can be observed while isolated N-terminal domain of EoCen (N-EoCen) or isolated long C-terminal domain of EoCen (LC-EoCen) was added into solution of ME. The interaction between EoCen and ME is specified exclusively for the short C-terminal domain of EoCen. On the basis of fluorescence titration curves, the conditional binding constants of ME with EoCen and SC-EoCen were calculated to be logKME-EoCen = 6.81±0.33 and log- KME-SC-EoCen = 6.51±0.45, respectively.

关键词：蜂毒肽光谱缩氨酸生物学

The role of cupric in maintaining the structure of CopC

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Chinese Science Bulletin 2007年第6期52卷 743-747页

作者： ZHENG XiaoYan PANG ErGuo LI HuiQin zhao yaqin YANG BinShengt Institute of Molecular Science Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education ShanxiUniversity Taiyuan 030006 China

The CopC protein from pseudomonas syringae pathovar tomato is expressed as one of four proteins encoded by the operon CopABCD that is responsible for copper resistance. And there are one trypto-phan (83), one tyrosine (79), and three phenylalanines (35, 43, 99) in apoCopC. The fluorescence peak of apoCopC is located near 320 nm, and the peak shifts toward 353 nm in the presence of 10 mmol·L^(-1) urea with excitation at 280 nm. Using urea as a chemical agent, the conformational stabilities of apoCopC and Cu_N^(2+) -CopC were monitored by fluorescence spectrum in 20 mmol·L^(-1) phosphate buffer and 100 mmol·L^(-1) sodium chloride at pH 6.0. The free energy of stabilization for apoCopC and Cu_N^(2+)-CopC is 16.29±0.65 kJ·mol^(-1) and 26.26±0.35 kJ·mol^(-1), respectively. The distance between the tryptophan residue and the Cu^(2+) in Cu_N^(2+) -CopC has been studied by observing Frster type nonradia-tive energy transfer. And it is calculated to be 11.6 .

关键词：二价铜 CopC 蛋白质结构构象稳定性作用尿素变性

Metal ion-binding properties of wild-type and mutant D37K of ciliate Euplotes octocarinatus centrin

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Chinese Science Bulletin 2010年第27期55卷 3118-3122页

作者： LIU Wen DUAN Lian zhao yaqin LIANG AiHua YANG BinSheng Institute of Molecular Science Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education Shanxi University Taiyuan 030006 China Institute of Biotechnology Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education Shanxi University Taiyuan 030006 China

Ciliate Euplotes octocarinatus centrin (EoCen) is an EF-hand calcium-binding protein closely related to the prototypical calcium sensor protein *** first amino acid of the Ca2+-binding loops found in the EF-hand calcium-binding proteins is a highly conserved aspartic acid *** D37K mutant was produced to elucidate the metal binding role of the first aspartic acid of the EF-loop I of ***-sensitized Tb3+fluorescence results indicated that the metal binding ability of loop I was lost due to the D37K *** on fluorescence titration curves of Lu2-D37K,the conditional binding constants of the EoCen loop II were quantitatively found to be KII=(1.61±0.04)×105 L mol-1 and KII=(3.52±0.08)×102 L mol-1 with Tb3+ and Ca2+,*** 2-p-toluidinylnaphthalene-6-sulfonate as a hydrophobic probe,exposure of the hydrophobic surface upon metal binding was found to be significantly reduced for the metal ion-saturated EoCen D37K mutant.

关键词： centrin 金属离子突变型纤毛虫结合特性游仆虫野生型钙结合蛋白

The properties of XPC peptide binding with human centrin 2

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The properties of XPC peptide binding with human centrin 2

一种基于小生境遗传算法的中文文本聚类新方法

中国化学会第十四届全国生物无机化学学术会议

作者： Jing Yang yaqin zhao Institute of Molecular Science Key Laboratory of Chemical Biology of Molecular Engineering of Education Ministry Shanxi University

Properties of XPC peptide binding to phosphorylated human centrin 2(HsCen2p) and human centrin 2(HsCen2) were characterized by fluorescence spectra, circular dichroism(CD) and isothermal titration calorimetry(ITC) in 10 mM Hepes(pH 7.4, 25 ℃). The results showed that after being phosphorylated alpha helix content and hydrophobic surface exposure of HsCen2 was decreased significantly. HsCen2 formed a 1:1 complex with XPC peptide, and their conditional stability constant was calculated to be 1.9×10 L/mol. And HsCen2p has no affinity with XPC peptide.

关键词： centrin phosphorylation XPC peptide

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计算机工程 2006年第6期32卷 206-208页

作者：赵亚琴周献中南京理工大学自动化系南京210094 南京大学工程管理学院南京210093

针对传统c-均值等算法在文本聚类中的缺陷,提出了一种基于小生境遗传算法的中文文本聚类新方法,将文本集的聚类问题转化为多峰函数的优化问题。以多峰函数的峰值代表文本的聚类中心,聚类的数目不必预先给定。描述了该聚类方法实现文本... 详细信息

针对传统c-均值等算法在文本聚类中的缺陷,提出了一种基于小生境遗传算法的中文文本聚类新方法,将文本集的聚类问题转化为多峰函数的优化问题。以多峰函数的峰值代表文本的聚类中心,聚类的数目不必预先给定。描述了该聚类方法实现文本聚类时适应值函数的构造方法以及小生境半径的动态估计方法。实验结果表明,该方法提高了文本聚类的平均准确率。

关键词：排挤小生境文本聚类多峰函数密度估计

Effects of Tb3+ on the aggregation properties of phosphorylated human centrin 2

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Effects of Tb3+ on the aggregation properties of phosphoryla...