TiO2 Immobilized Biodegradable Polymer for Photocatalytic Removal of Chlorophenol

This study concentrated on the direct immobilization of anatase nano titanium dioxide particles (TiO₂, 44?nm particle size) into or onto a biodegradable polymer, polycaprolactone, by solvent-cast processes. The photocatalytic properties of the produced materials were tested by photocatalytic removal of organic contaminant 4-chlorophenol. Produced TiO₂ immobilized polymer successfully removed 4-chlorophenol (4-CP, 20?ppm which is equal to 1.56?×?10^?4?M) from aqueous solution without additional pH arrangement employing a UV-A light (365?nm) source. Immobilization of n-TiO₂ onto polycaprolactone (PCL) produced improved 4-CP removal percentages, reaching to nearly 85?%. Increased PCL mass significantly increases the removal percentage of 4-CP. When a UVC lamp emitting 254?nm light is used, the removal percentage reaches to 89?%. UV irradiation did not cause any change in the microstructure of the polymeric material (confirmed with ATR-FTIR analysis). This is an important evidence that the material could be reused for further photocatalytic treatments. Produced material seems to be highly promising for successful removal of organic pollutants beside its biodegradable nature.     

依托云班课的生物化学实验课程改革实践

针对传统实验课存在的弊端,结合现代信息技术,将云班课应用于《生物化学实验》教学实践。根据《生物化学实验》课程的特点和课堂教学中存在的问题,详细阐述了基于云班课的生物化学实验课程改革实践的具体做法及在教改过程中的一些思考,旨在提高《生物化学实验》的课堂教学质量。课改实践结果表明:学生学习兴趣、学习效果、实验操作技能等均有明显的提高,可为其他同类院校生物化学实验教学改革提供借鉴。     

基于纹理分析的香菇品质分选方法

为了实现天白花菇、白花菇、茶花菇和光面菇这4种类型香菇的分选,研究了多种菌盖纹理模型以及各个模型参量的融合,并设计了整个香菇类型自动分选系统。首先从香菇菌盖中截取合适大小的纹理区域,利用灰度直方图统计,灰度共生矩阵(grey level co-occurrence matrix),高斯马尔科夫随机场(Gauss Makov Random Field)模型和分形维数模型从该区域中共提取23个纹理特征参数。然后使用顺序前向搜索法对各个模型特征数据进行融合,从中得出6个简约特征。最后构建K近邻分类器作为香菇类别分类器并对提取后的简约特征进行分类。试验结果表明,香菇类型分选模型的分选正确率可达到93.57%,利用香菇菌盖纹理对香菇进行类型分类是可行的。     

论我国农业技术推广机制与方法的创新

通过对我国农业技术推广发展阶段、组织状况、经费状况进行分析,指出我国农业技术推广体系存在的问题,并提出了我国农业技术推广的新机制和新方法。     

苜蓿种植技术要点

本文分析了4个苜蓿品种的产量表现、选择适宜种植的品种,提出苜蓿种植技术要点。     

流动资产营运与盈利性、成长性关系分析——对中国农业上市公司的实证研究

一般认为,企业的流动资产营运能力越强,其盈利能力、成长能力就会越强。为了验证该假设,笔者以中国农业上市公司2003—2006年9月的相关数据为样本,运用多元回归模型研究了中国农业上市公司流动资产营运能力与盈利性、成长性的内在关系,发现正如所预期,农业上市公司的盈利性、成长性与存货周转率、应收账款周转率正相关。也就是说,公司的存货、应收账款周转速度越快,流动资产创造的利润就越高,其成长能力越强。从回归系数来看,存货周转率的回归系数较高,应收账款周转率的回归系数较小,说明农业上市公司在流动资产的营运管理上,应该更侧重于存货管理。在此基础上,对如何改善中国农业企业的流动资产管理提出了对策建议:农业企业应该加强对存货和应收账款的管理,努力提高其存货周转率和应收账款周转率。     

重金属中毒体内解毒机理研究——金属硫蛋白在动物铜、镉中毒与解毒中的作用

金属硫蛋白(Metallo thioncin,MT)是动物体内泛在性蛋白质,能捕获进入体内的重金属如铜、镉等。起固定、保存重金属元素、解除离子态重金属的毒性作用,三硫钼酸钠可以使与金属硫蛋白结合的铜、镉解离,但MT的分子量不变。离开MT后的金属离子可进入血液,与白蛋白结合,使血浆铜浓度及血浆三氯醋酸(TCA)沉淀物中铜浓度升高,更多的铜则进入胆汁,经粪便排出体外。硒酸钠和亚硒酸钠有类似的作用,可使与MT结合的镉解离,并转移到结合强度较小,而分子量较大的蛋白质上,有一定的促进镉排泄的作用。因此,血浆铜及血浆TCA沉淀物中铜浓度升高,可作为监测钼诱导缺铜病早期阶段的指标,硫钼酸钠可作为绵羊、山羊铜中毒,人的Wilson氏病的特效治疗药,亦可作为鱼铜中毒时的去铜剂,甚至可望成为慢性镉中毒的去镉剂。     

Intracellular calcium release mediated by sphingosine derivatives generated in cells

Soluble and hydrophobic lipid breakdown products have a variety of important signaling roles in cells. Here sphingoid bases derived in cells from sphingolipid breakdown are shown to have a potent and direct effect in mediating calcium release from intracellular stores. Sphingosine must be enzymically converted within the cell to a product believed to be sphingosine-1-phosphate, which thereafter effects calcium release from a pool including the inositol 1,4,5-trisphosphate-sensitive calcium pool. The sensitivity, molecular specificity, and reversibility of the effect on calcium movements closely parallel sphingoid base-mediated inhibition of protein kinase C. Generation of sphingoid bases in cells may activate a dual signaling pathway involving regulation of calcium and protein kinase C, comparable perhaps to the phosphatidylinositol and calcium signaling pathway.     

抗虫杂交棉的制种及推广

近年来,抗虫棉在黄河三角洲(东营)推广速度很快,全市抗虫棉普及率已达到100%,其中抗虫杂交棉达40%。去年11月份,我市又配出新抗虫杂交品种——华棉1号(暂定名),该品种抗病、抗虫、抗寒、耐盐碱等,是抗逆性强的杂交棉。抗虫杂交棉,弥补了常规抗虫棉产量低和常规品种不抗虫的缺陷     

van der waals interactions in the Cl + HD reaction

The van der Waals forces in the entrance valley of the Cl + HD reaction are shown here to play a decisive role in the reaction's dynamics. Exact quantum mechanical calculations of reactive scattering on a potential energy surface without Cl-HD van der Waals forces predict that the HCl and DCl products will be produced almost equally, whereas the same calculations on a new ab initio potential energy surface with van der Waals forces show a strong preference for the production of DCl. This preference is also seen in crossed molecular beam experiments on the reaction. The study of chemical reaction dynamics has now advanced to the stage where even comparatively weak van der Waals interactions can no longer be neglected in calculations of the potential energy surfaces of chemical reactions.