纳米活性沉淀剂去除硫酸亚铁中的锌及重金属研究

进入21世纪以来能源危机日益凸显,加之国家环境保护政策和法规的推行,以电能为核心的清洁新能源的开发利用受到从未有的重视,其中大容量蓄电池的研究和制造成为热门课题。硫酸亚铁是生产电池材料磷酸亚铁锂（LiFePO4）的前驱体材料,对硫酸亚铁中的锌、铅等重金属含量有严格的限制,研究表明纳米活性复合沉淀剂能有效去除硫酸亚铁中的锌及重金属,保障磷酸亚铁锂等电池材料的质量,使硫酸亚铁的应用范围得到拓展。     

Use of ionic liquids in recycle of palladium catalysts for synthesis of polyketone

Room temperature ionic liquids as solvents for palladium-catalyzed copolymerization of carbon monoxide and styrene were prepared by reaction of aqueous lead tetrafluoroborate with correspond-ing chloride or bromide salts. The recyclability of palladium composite catalyst in various ionic liquids was investigated.[Pd(bipy)2][BF4]2 showed a lower catalytic activity than [Pd(bipy)2][PF6]2 in similar conditions, although the catalytic activity of each composite catalyst in ionic liquids still existed after 4 successive recycles. It was shown the catalytic activity of palladium composite catalyst was higher than that of the catalyst formed in situ from palladium acetate, 2,2'-bipyridyl, and HA (A=PF6-, BF4-) in ionic liquids. The effects of volume of ionic liquids, reaction time, and the dosage of benzoquinone on the copolymerization were also studied.     

纳米银/聚丙烯酰胺/乙烯-醋酸乙烯酯共聚物复合材料的电性能

Nano-Ag particles/polyacrylamide （PAM） composites were synthesized by γ irradiation method and then blended with ethylene vinyl acetate （EVA）. Dielectric behaviors of the Ag/PAM/EVA composites are investigated as a function of both the concentration and size of Ag particles. When concentration of the Ag fillers is rarely low, dielectric anomalies were first observed in contrast to the traditional percolation theory. As concentration of Ag increases, volume resistivity and breakdown field strength are enhanced, loss tangent （tan δ） reduced and dielectric constant kept invariable. In addition, the above variation became larger when the diameter of the Ag nano-particles is smaller. Such dielectric anomalies may be understood by considering the unique ＂Coulomb Blockade Effect＂ of the nano-sized Ag particles.     

用于乙醇-水分离的SA-PVA/PSF中空纤维渗透汽化复合膜

Using polysulfone (PSF) hollow fiber ultrafiltration membranes as the substrate, sodium alginate (SA) and polyvinyl alcohol (PVA) blend solutions as the coating solution, and maleic anhydride (MAC) as the cross-linked agent, SAPVA/PSF hollow fiber composite membranes were prepared for the dehydration of ethanol-water. The effects of different sodium alginate concentration in the coating solutions and different operating temperatures on pervaporation performance were investigated. The experimental results showed that pervaporation performance of the SA-PVA/PSF composite membranes for ethanol-water solution exhibited a high separation factor although they had a relatively low permeation flux. As SA concentration in SA-PVA coating solution was 66.7% and the operating temperature was 40 ℃, SA-PVA/PSF hollow fiber composite membrane (PS4) had a separation factor of 886 and flux of 12.6 g/(m2·h). Besides, SA-PVA/PSF hollow fiber composite membranes (PS3 and PS4) were used for the investigation of the effect of ethanol concentration in the feed solution on pervaporation performance.     

散体材料桩和水泥桩复合地基固结理论研究综述

复合地基在地基处理中具有十分重要的地位,其用于加固地基,增强地基承载力和减小地基沉降具有良好的效果,因而在工程中被广泛采用。由于研究复合地基的固结是研究复合地基加固机理的主要内容之一,土体的固结直接影响复合地基的变形和承载能力。因此,有必要对复合地基的固结理论进行全面、系统地认识。本文主要对散体材料桩和水泥桩复合地基的固结理论进行综述,阐述了复合地基固结理论研究的现状和取得的理论成果。     

中国传统文化与美国社会文化生成背景的比较

本文从文化生成背景的角度出发,探讨了中国传统文化和美国社会文化在形成过程中的差异。比较的目的并非强调差异,而在于增加相互了解、相互认同,从而促进跨文化交流。     

模板技术制备介观结构材料（英文）

模板技术是制备介观尺度下具有多重结构材料的简单有效方法。本工作围绕纳米微球及其组装结构，一维纳米纤维及其组装结构而开展。其中重点关于核-壳结构凝胶微球的制备，并以此为模板制备包覆复合微球和中空微球，实现复合微球的形貌和特征尺寸的控制。通过化学改性对单分散聚苯乙烯胶体微粒进行处理，制备了具有核-壳结构的单分散凝胶粒子。以核-壳结构凝胶粒子为模板，制备了二氧化钛包覆聚苯乙烯核壳结构的复合粒子及其中空的二氧化钛粒子。发现在无机前体的溶胶凝胶过程中，电场能诱导复合粒子表面形成贯穿的多孔结构。同样思路，制备了二氧化硅、导电聚苯胺及其复合的核-壳结构和相应的中空微球。对聚苯乙烯胶体晶进行化学改性，制备了核-壳结构的胶体晶凝胶。以此为模板，与第二种具有响应特性凝胶进行复合，得到了敏感特性的胶体晶凝胶。并研究了此复合凝胶的形态及外场响应特性。以多孔氧化铝膜为模板，制备一维结构及其阵列体系。通过调节孔的润湿性，调节一维结构的形态（纤维或中空结构）并可调节双组分核-壳结构纤维的内外相相反转。     

我国新型农业组织化:现实的必然选择

我国新型农业组织化是随着制度的变迁而产生的。社会主义市场经济体制的建立、家庭承包责任制的制度约束、农业产业化的兴起、破解“三农”问题、解决规模经营问题和国内现有的技术条件迫切需要农业组织化,中外农业组织化的经验教训也为我国农业组织化的形成提供了有利条件。对我国农业组织化成因加以探索,有利于维护农民利益,提高农业效率。     

生物模仿自装配的无机化胶原的纳米纤维(英文)

有序排列的纳米纤维集合体在自然界中普遍存在,例如骨骼、肌肉、头发.天然骨骼是一种复杂的生物无机化系统,它具有错综复杂的有序排列结构[1].它的集合形成是通过羟基磷灰石(HA)矿物在I型胶原有机间质中有序沉积而成.羟基磷灰石的晶形模型c轴取向与胶原纤维的取向一致.本文目标是制备一种似骨骼的磷灰石和磷灰石/胶原复合体.HA/胶原复合体的合成是用生物模仿策略,使复合体能与天然骨骼相似而能在临床广泛应用.复合体合成的关键步骤是在含水介质中胶原间质控制磷酸钙的成核和生长.但制备与骨骼相似而具有纳米尺度的任何材料,即使是最低等级有序排列组织的材料,也是一个挑战性问题.因为所制备的材料具有两种不相同的纳米相,有机和无机纳米相.已经研究出确定自装配HA/胶原复合体中胶原与矿物结晶之间的超结构关系.首次观测到一种新的胶原与羟基磷灰石复合体的自装配有序结构.已经研究成一种新型的骨骼代用材料,成功地进行了超过150例的临床实验.     

金属-介质复合体中的光学双稳

利用Maxwell—Gamett近似，结合谱表示和自洽平均场近似，从理论上研究了无规分布的旋转椭球金属颗粒浸在绝缘介质中而成的复合体在组分具有一般非线性时的光学双稳(OB)，讨论了two-OB现象及它们与金属颗粒退极因子和体积分数之间的关系，并给出了数值计算结果。