丁二烯在聚苯乙烯和丁苯多嵌段共聚物膜中扩散系数的测定与计算

用石英弹簧法测定了298．15K和308．15K下丁二烯在聚苯乙烯和丁苯多嵌段共聚物膜中的吸收曲线,结果表明丁二烯在聚苯乙烯膜和丁苯多嵌段共聚物膜中的吸收曲线近似呈费克型,扩散吸收曲线的形态与相对分子质量及其分布无关。用黄永民等的吸附一吸收双模式模型对实验结果进行了关联,获得无限稀释扩散系数和平衡溶解度。     

HL60细胞质膜上存在水通道蛋白

采用细胞影像系统,测定了ＨＬ６０细胞转运水分活力。结果表明,ＨＬ６０细胞在低渗介质中体积迅速增大,且随着渗透梯差的加大而显增大;在渗透液液的质量摩尔浓度梯差为１００,１５０,２００ｍｍｏｌ·ｋｇ＾－１下,Ｐｆ值分别为０．１４×１０＾－３,０．４０×１０＾－３,０．４３×１０＾－３ｃｍ·ｓ＾－１;并且发现ＨＬ６０细胞转运水分活力可以被ＨｇＣｌ２抑制,由此可见,ＨＬ６０细胞转运水分活力表现出典型的水     

Lipid transport in microorganisms

Summary Microorganisms are useful model systems for the study of intracellular transport of lipids. Eukaryotic microorganisms, such as the yeastSaccharomyces cerevisiae, are similar to higher eukaryotes with respect to organelle structure and membrane assembly. Experiments in vivo showed that transport of phosphatidylcholine between yeast microsomes and mitochondria is energy independent; transfer of phosphatidylinositol to the plasma membrane and the flux of secretory vesicles take place by different mechanisms. Linkage of transfer and biosynthesis of phospholipids was demonstrated in the case of intramitochondrial phospholipid transfer. A yeast phosphatidylinositol/phosphatidylcholine transfer protein, which is essential for cell viability, was isolated and characterized. Another phospholipid transfer protein present in yeast cytosol, which has a different specificity, is currently under investigation. Transfer of phospholipids between cellular membranes was also demonstrated with prokaryotes. The cytoplasm and the periplasma of the gram-negative facultative photosynthetic bacteriumRhodopseudomonas sphaeroides contain phospholipid transfer proteins; these seem to be involved in the biosynthesis of prokaryotic membranes.     

SnO2纳米线阵列的制备及纳米器件的制作

采用简单的溶胶-凝胶方法在多孔阳极氧化铝模板(AAM)的微孔中制备了高度有序的SnO2纳米线阵列。XRD,SEM和TEM对样品进行了结构和形貌的表征,结果表明,高度有序的SnO2纳米线具有四方相的多晶结构,纳米线连续均匀;并对SnO2纳米线阵列的生长机理进行了探讨;最后用聚焦离子束沉积设备制作了单根SnO2纳米线器件。     

均布荷载下受有预加张力圆薄膜的轴对称变形

针对受有预加张力的弹性圆薄膜结构,利用F ppl-von Krmn薄膜理论建立基本方程,推广了Hencky变换,得到了均布荷载作用下受有预加张力弹性圆薄膜轴对称大变形的一般解。给出了圆薄膜中心挠度,径向和环向薄膜内力的幂级数形式计算公式。研究表明:当预加张力相对于荷载很小的情况下,解答趋近于Hencky理论结果;当预加张力相对于荷载很大的情况下,解答趋近于线性理论结果。研究结果可用于薄膜预张力测量技术的理论分析。     

无机膜应用于废润滑油再生

废润滑油污染对环境的潜在危害正日益显现,传统的废润滑油再生方法产生大量的酸性淤泥,造成二次污染,故提出膜分离应用于废润滑油再生的新思路,根据废油的特点来选取合适的膜来处理废润滑油,并利用降低油液黏度和压力膜过程来提高膜的渗透通量,使膜的渗透通量明显增加.     

Trichloroacetate affects the EPR SignalⅡslow and SignalⅠin the thylakoid of Chlamydomonas reinhardtii

One electron paramagnetic resonance (EPR) signal, named SignalⅡslow, originates from the oxidized Tyrosine 160 (YDo) of D2 polypeptide of photosystemⅡ reaction center. After adding high concentration trichloroacetate (TCA) to the Chlamydomonas reinhardtii thylakoid suspension, this signal was abolished in a minute. Treatment of TCA also removes a few of polypeptides, including three extrinsic polypeptides of oxygen-evolving complex, from the thylakoid membrane. Based upon the analysis of the microenvironment around YD with a three-dimensional model, it is indicated that relatively high hydrophobicity of this microenvironment may be the essential prerequisite for TCA to affect YD. It has been observed that TCA treatment also retards the decay of the SignalⅠ, produced by the oxidized reaction center chlorophyll dimer (P700+) of photosys- temⅠ.     

基于Ni@Pt燃料电池型甲醛电化学传感器的研究

通过热裂解和氢还原制备了Ni纳米颗粒,并在酸性溶液中通过液相置换合成了核壳 Ni@Pt-800。采用喷涂法将催化剂作为阴极涂层附着在质子交换膜上,阳极涂层为商业Pt/C。采用透射电子显微镜、X射线光电子能谱仪、X射线衍射仪对催化剂结构进行表征。结果表明,Ni@Pt-800对甲醛的响应分别是Ni@Pt和其他干扰气体的4.95倍和25倍。在0～135×10^?6范围内,甲醛的氧化峰电流与浓度有着良好的线性关系,其线性回归方程为：△i=0.00103×10^?6－0.006 61,相关系数为0.98。     

Sr掺杂SiO2膜的制备及其脱盐性能研究

以正硅酸四乙酯(TEOS)为硅烷前驱体,以氯化锶(SrCl₂)为Sr源,采用溶胶-凝胶法制备了Sr掺杂的SiO₂膜.通过系列表征结果证实:在水解缩合反应过程中Sr被掺杂到SiO₂骨架中,形成了水热稳定的Si—O—Sr键,明显地改变了膜的表面形貌、微观结构和亲水性,从而提高了膜的脱盐性能和稳定性.在优化合成条件(n(Sr):n(TEOS)=0.075:1.000)下所制备的Sr/SiO₂膜的脱盐性能最佳.在60 ℃条件下,当以质量分数为3.5%的NaCl溶液为进料液时,该膜的水通量高达20.7 kg·m^-2·h^-1,盐截留率接近100.0%.此外,在35～60 ℃连续性温度循环测试中,该膜显示出了优异的水热稳定性.     

高频喷射呼吸机在鼻咽部产生的射流对兔咽部粘膜的影响

使用高频喷射呼吸机兔子鼻咽部进行人工通气处理，选择常规的治疗参数。分别于处理后０、４、８、１２、１６、２０和２４ｈ处死动物，取咽部粘膜进行光镜、透射电镜和扫描电镜观察。其中“０”处理对照组。结果表明；４ｈ后咽粘膜开始发生充血；８ｈ后可发生粘膜上皮变性，坏死和脱落，间质发生炎症及出血反应等，病变随使用呼吸机时间延长而加重。