双酚A分子印迹聚合物膜的制备与其性能研究

通过实验获得了双酚A分子印迹共混膜的相转化制备的工艺条件,并且研究了膜材料、铸膜液的组成和温度、分子印迹聚合物填充的情况、凝固浴的组成和凝固的温度、暴空时间以及膜的厚度等因素对膜的结构与性能的影响,对以此方法制备分子印迹膜提供了通用的理论指导。利用浓差推动渗透实验对所制备的共混膜进行了拆分机理分析,根据膜过程溶解一扩散原理建立了传质模型。实验结果表明,分子印迹共混膜对双酚A表现出了高度的识别性。     

THYESS法结合QSAR分析对环境内分泌干扰性物质的筛检研究

利用THYESS法对几种典型的环境内分泌干扰物质的毒理活性进行了定量筛检，并进一步结合量子化学对被检物质作了QSAR分析．结果表明，用THYESS法筛检出的环境内分泌干扰物质存在着良好的毒活性．反应剂量关系．这种测定方法再结合量子化学的QSAR分析，有望成为获得大量环境样品中EDCs毒害数据的一种良好方法．     

Development of an analytical method to determine phenolic endocrine disrupting chemicals in sewage and sludge by GC/MS

An analytical method has been developed to determine hisphenoi A and five degradation products of alkyiphenoi ethoxylates in sewage and sludge. The parameters of accelerated solvent extraction （ASE） were optimized. C18 cartridge was used to clean up the sewage and the extract of sludge. The sensitivity of the mass detector was improved by adjusting the voltage of the lens manually. The instrumental detection limit was 3.2-17.8pg. The method detection limits were 2.5-11.4 ng/L and 0.3-2.1ng/g for sewage and sludge analysis respectively. The recovery and relative standard deviation for sewage analysis were 79.2%-111.4% and 6.9% - 12.6%; for sludge analysis were 68.5% - 114.0% and 8.9%-16.0%. Finally this method was applied to determining the phenolic endocrine disrupting chemicals in sewage and sludge from a sewage treatment plant in Beijing.     

渭河陕西段环境内分泌干扰物BPA水质基准研究

基于USEPA ECOTOX水生生物毒理学数据,采用物种敏感度分布曲线法(SSD)和自然对数-累积概率型分布拟合法对渭河陕西段中的环境内分泌干扰物双酚A(BPA)的水质基准(WQC)进行了研究。研究结果显示:渭河陕西段中BPA基准最大浓度(CMC)为403μg/L,基准连续浓度(CCC)为80.6μg/L。此外,还给出了渭河陕西段中BPA水质基准的累积正态分布函数与概率密度函数。最后,对渭河陕西段中BPA的WQC进行了确定性分析,分析结果认为在相关假设前提下BPA的WQC具有一定的参考价值,其确定性概率介于71.43%～100%。     

光电催化降解双酚A的研究

采用sol—gel法制备TiO2薄膜光电极,以该电极为工作电极,铂丝为对电极,饱和甘汞电极为参比电极,对双酚A的光电催化降解进行了研究,结果表明：该电极具有“型半导体的特征行为．外加偏压为＋0．8V、pH=4,0．88mmol／L的H2O2中,对初始浓度为0．22mmol／L的双酚A溶液光照180min,降解率达70．24％,讨论了氧的存在、外加偏压、双酚A浓度和pH值等因素对光电催化反应的影响。     

Quantitative structure-activity relationship and prediction of mixture toxicity of alkanols

Alkanols, which are narcotic compounds, were studied. The acute toxicities (15min-EC50) of 15 alkanols, which have a large span of hydrophobicity, to Photobacterium phosphoreum were measured. Quantitative structure-activity relationship (QSAR) analysis of single toxicity of alkanols was conducted by using octanol-water partition coefficient (logKow). The polynomial expression was used instead of linear equation to develop QSAR model, and a QSAR model with a good predictive potential was achieved. Furthermore, the mixture toxicity of alkanols was studied. In order to predict joint toxicity of mixtures that contain very hydrophobic alkanols, the adjustment of octanol-water partition coefficient was performed, considering the influence of volume effect. And equivalent octanol-water partition coefficient was introduced. The QSAR model of mixture toxicity was developed by using equivalent mixture octanol-water partition coefficient. The result showed that even a linear model could predict mixture toxicity well by using equivalent mixture octanol-water partition coefficient.     

有机羧酸对蒙脱石光催化转化水中双酚A的影响

为了研究有机羧酸和黏土矿蒙脱石之间的相互作用引发的光化学过程对污染物迁移转化的影响,选择2种常见的有机羧酸草酸和柠檬酸,在250W的金属卤化物灯(λ≥365nm)照射下,研究了草酸和柠檬酸对天然蒙脱石和蒙脱石KSF光催化降解内分泌干扰物双酚A(BPA)的过程,探讨了反应pH值、溶解氧对BPA光降解的影响.实验结果表明:草酸、柠檬酸可以促进蒙脱石光催化降解水中BPA,特别是对于天然蒙脱石,草酸和柠檬酸可以显著提高其光催化氧化能力,1h的光反应,BPA的降解率分别约为95%和84%,降解动力学符合Langmuir-Hinshelwood方程,同时降解率受pH值的影响较大,在pH值2.0~4.0范围内,随着pH值的增大而增大,当pH=4.0时达到最大,然后迅速减小.溶解氧的存在有利于促进体系中BPA的光降解.     

Measurement of the free concentrations of alkyl phenols and bisphenol A to determine their biodegradation kinetics by activated sludge

A negligible depletion-solid phase microextraction (nd-SPME) method is developed to measure free concentrations of two alkyl phenols (4-t-octylphenol, nonylphenol) and bisphenol A in activated sludge, with which aerobic biodegradation kinetics of three pollutants was determined. For the degradation of octylphenol, nonylphenol and bisphenol A, the apparent rate constant based on total concentration is 0.02, 0.01 and 0.03 h-1, respectively; with the half life being 34.9, 54.3 and 22.3 h correspondingly. Meanwhile, real rate constants based on free concentration are 0.74, 0.60 and 1.03 h-1, respectively; with the half life being 0.9, 1.2 and 0.7 h accordingly. Differences between two constants revealed that desorption of targeted pollutants from activated sludge should be the rate-limiting step. Compared to the rapid biodegradation of alkyl phenols and bisphenol A in free state, the desorption of pollutants from the sludge is relatively slow, which made the apparent biodegradation rate constants much lower.     

Holographic QSAR of estradiol derivatives

Holographic QSAR model is constructed to predict relative binding affinities of estradiol derivatives with lamb uterine estrogen receptor.The method does not require the generation of three-dimensional structure of the compounds.The factors that influence the quality of QSAR model are discussed.The result indicates that the model has good predictability and yields a high q^2LOO value of 0.897,Compared to other QSAR methods,the HQSAR technique is suitable for use in screening large database of chemicals.     

双酚A类同系物的雌激素效应及对MCF-7细胞的毒性

双酚A(bisphenol A, BPA)及其类似物作为聚碳酸酯的主要合成原料, 一直是环境污染的重要问题, 其环境分布及人体暴露是当今科学研究的热点. 为评估环境中BPA 类物质的毒性效应, 采用MTT 比色法检测了7 种BPA 类同系物对人雌激素受体(estrogen receptor,ER)缺失乳腺癌细胞MCF-7(ER–) 增殖活性的影响. 通过检测细胞乳酸脱氢酶(lactate dehydrogenase, LDH)露出率评估了目标物对MCF-7 细胞膜的损伤, 结果表明, 在0.01～1.00 μmol/L 浓度范围内, 受试化合物对MCF-7 细胞的毒性较小, LDH 少量露出; 而在10 和100 μmol/L 浓度下, 细胞增殖受到显著抑制, 细胞膜通透性显著改变, LDH大量露出. 同时采用ER 基因双杂交酵母实验检验了这几种BPA 类同系物的雌激素效应大小, 通过Logistic 模型对曲线进行了拟合, 并以模型估算的半数透导活性(EC50) 评估了7 种BPA 类同系物的雌激素效应活性, 其大小依次为TDP>BPAF>4Cl-BPA>BPC>BPA>BPE>BPAP. 这说明其雌激素效应机制可能是通过和ER 结合而产生的.     

新型纳米复合杂多酸催化剂H3PW12O40/SiO2催化合成双酚A的研究

研制了新型复合杂多酸钠米粒子H3PW12O40／SiO2，并用于催化合成双酚A；用IR、XRD、TEM等研究了它的结构形态，考察了原料配比、反应时间、反应温度、催化剂用量等对催化性能的影响，实验结果表明，使用溶胶凝胶法得到的纳米复合杂多酸催化剂，双酚A单程收经达到65．5％。     

g-C3N4@N-TNA制备及其光催化降解双酚A应用

采用电刻蚀-气氛煅烧-浸渍-煅烧法成功制备出g-C3 N4负载N掺杂T iO2纳米管阵列(g-C3 N4@N-TNA)光催化剂,对其进行了X-射线衍射(XRD)、扫描电子显微镜(SEM)、紫外-可见(UV-Vis)漫反射、X射线光电子能谱(XPS)、光电分析系统测试表征,并对双酚A(BPA)进行了光降解实验.结果发现,...     

双酚A在多壁碳纳米修饰电极上电化学性质及其测定研究

 制备出1种多壁碳纳米管化学修饰电极,详细研究了双酚A(SPA)在多壁碳纳米管化学修饰上的电化学行为,并提出了一种灵敏的、简便的直接检测双酚A的电化学分析方法.在0.30V富集后,双酚A在多壁碳纳米管修饰玻碳(MWNT-GCE)电极上出现一个灵敏度高、峰形好的氧化峰.在pH7.0的磷酸盐缓冲溶液中峰电位位于0.58V.多壁碳纳米管薄膜对双酚A的氧化表现出一定的催化作用,能显著提高双酚A的氧化峰电流.优化了测定参数如:底液的pH,修饰剂的用量、扫描速度,富集时间等.双酚A的氧化峰电流与其浓度在5.0×10^-8～2.0×10^-5mol·L^-1之间有很好的线性关系.富集3min后的检出限为2.0×10^-8mol·L^-1.用此方法测定了塑料中双酚A的含量,结果满意.     

双酚A的分子烙印聚合物的制备和结合特性的研究

使用了不同的功能单体和致孔剂,制备了一系列的以双酚A为模板的分子烙印聚合物.发现以2-Vpy做功能单体,以甲苯做致孔剂的分子烙印聚合物对底物有很好的结合能力.在不同的致孔剂中,双酚A与功能单体形成复合物而导致它的质子的化学位移的变化幅度不同,表明形成的复合物的稳定程度不同,相对应的分子烙印聚合物的选择性结合底物的能力不同.Scatchard方程研究表明在研究的浓度范围内在聚合物中形成了一类等价的结合位点,结合位点对模板分子的最大表观结合量为 148.1 μmol·g -1;结合位点的平衡离解常数2.81 mmol/L. 研究表明,改变溶解底物的溶剂,会严重影响聚合物对底物的结合能力.     

分散液液微萃取-高效液相色谱法联用检测豆浆中双酚A的质量浓度

建立一种采用分散液液微萃取-高效液相色谱法(dispersive liquid-liquid microextraction coupled with high performance liquid chromatography, DLLME-HPLC)联用对豆浆中的双酚A进行萃取和检测的新方法, 并考察不同因素对萃取回收率和富集倍数的影响. 实验结果表明, 在最优化的萃取条件下, 在1~100 μg/L质量浓度范围内, 双酚A的质量浓度与色谱峰面积呈良好的线性关系, 检出限为0.3 μg/L, 加标回收率在91.6%~97.5%之间, 相对标准偏差小于6%. 这说明该方法的准确度和重现性较好, 具有可行性, 适用于对市售豆浆饮品中双酚A质量含量的测定.     

基于支持向量机处理圆度误差

提出一种基于支持向量机计算圆度误差的方法.支持向量机的理论基础是Vapnik创建的统计学习理论.它采用结构风险最小化准则,在最小化样本点误差的同时,缩小模型预测误差的上界,从而提高了模型的泛化能力.该方法采用支持向量机对圆度误差评价,克服了传统圆度最小二乘法评价的局部收敛问题.仿真实验结果表明介绍的方法可以有效、正确地评价圆度误差.     

NA样本下线性模型回归系数的一类估计的强相合性

线性模型有着广泛的应用,其回归系数的估计是确定模型的关键,这方面已有不少有意义的研究工作(如文献[1]-[3]等)。本文在NA样本下,构造出了线性模型回归系数的一类估计,并证明了这类估计的强相合性。     

壮语亲属词语义关系量变的回归分析

壮语亲属词中的汉借词使早期的亲属语义关系发生了量变，且这种量变在壮语方言中具有随机性。文章以“亲属语义关系”为因变量，亲属词的“变异均值”为自变量，用回归分析的方法确定了两个变量间单向正相关的因果属性。     

A Quantitative Analysis on Avicennia marina Community along Beihai Coast of Guangxi

This paper deals with species diversity,interspecific correlation and populationdistribution pattern of Avicennia marina community along Beihai coast,Guangxi.The results areas follows:(1)The floristic composition and structure of the community are rather simple;(2)Compared with those of terrestrial nature communities,the degrees of interspecificcorrelations of the community are much low;(3)Populations of A.marina and Kandelia candel show random distribution,while Aegicerascorniculatum population is an aggregated distribution.     

A novel molecular distance edge vector as applied to chemical modeling of quantitative structureretention relationships： Various gas chromatographic retention behaviors of polychlorinated dibenzofurans on different polarityvarying stationary phases

Based on the identical group as a pseudo atom instead of a typical atom, a novel modified molecular distance-edge （MDE） vector μ was developed in our laboratory to characterize chemical structure of polychlorinated dibenzofurans （PCDFs） congeners and/or isomers. Quantitative structure-retention relationships （QSRRs） between the new VMDE parameters and gas chromatographic （GC） retention behavior of PCDFs were then generated by multiple linear regression （MLR） method for non-polar, moderately polar, and polar stationary phases. Four excellent models with high correlation coefficients, R=0.984--0.995, were proposed for non-polar columns （DB-5, SE-54, OV-101）. For the moderately polar columns （OV-1701）, the correlation coefficient of the developed good model is only 0.958. For the polar columns （SP-2300）, the QSRR model is poor with R=0.884. Then cross validation with leave-one out of procedure （CV） is performed in high correlation with the non-polar （Rcv=9920.974） and weakly polar （Rcv=921） columns and in little correlation （Rcv=0.834） with the polar columns. These results show that the new μ vector is suitable for describing the retention behaviors of PCDFs on non-polar and moderately polar stationary phases and not for the various gas chromatographic retention behaviors of PCDFs on the different polarity-varying stationary phases.