铝与社会

铝在19世纪80年代以前被认为是一种珍贵的金属,随着现代冶炼铝的产生,它的身价大幅度下跌。但由于它具有许多优良性能,很快得到了广泛的应用,科学家认为20世纪是“钢铁时代”和“铝器时代”交替的时代。本文从铝的历史、铝的应用、铝及其化合物等方面论述铝在人类社会发展中的重要作用。     

铝先生的诊疗

自铝第一次被化学家发现并在实验室制备至今,铝一直与人类如影随形,铝及其化合物在生产和生活中有着重要的应用。本文将铝拟人化,以"诊疗"的形式,采用对话体,回顾了铝的发现史和应用史。     

红壤利用方式对铝形态和毒性的影响

研究了红壤不同利利用方式对铝的活性和形态的影响。结果表明：四种活性铝的提取剂对土壤中铝的提取力顺序一般为０．５ｍｏｌ／ＬＮａＯＨ＞１ｍｏｌ／ＬＨＣｌ＞１ｍｏｌ／ＬＮＨ４Ａｃ＞１ｍｏｌ／ＬＫＣｌ。土壤中水溶性铝含量对土壤酸度十分敏感。     

铝氟联合中毒暨铝引起少儿钙磷铁锌生物有效利用不良综合征

对某村普查筛出的铝氟联合中毒病人及高氟,高氟铝、高铝的实验种鸡进行动态研究。结果表明,氟含量〉４０＊１０＾－６的主食玉米促成了一般摄铝浓度人群的铝吸收和蓄积,饲铝超过一般浓度１－４倍的童鸡便有肝、肾铝蓄积、骨铝反而显著下降,但均出现低龄人群和实验动物的高钙血和高骨矿性骨营养不良软化,高全血磷的ＡＴＰ生成减少,全血铁增高的缺铁性小细胞性贫血,低锌症,智能和体能下等钙磷铁锌生物有 良和低素质综合症,随     

直读光谱法测定钢中酸溶铝和酸不溶铝

钢中铝的存在形式主要有两种 ,一种是以金属固溶体状态存在 ,另一种是以化合态非金属夹杂物形式存在 ,如氧化铝、氮化铝、铝的硫化物等。在湿法化学分析中认为 ,用无机酸溶样时 ,金属铝和氮化铝及铝的硫化物均被溶解 ,习惯上称这一部分为“酸溶铝”。它在一定范围内有利于细化晶粒 ,提高钢的使用性能。而氧化铝难溶于酸 ,这一部分称为“酸不溶铝”,它降低了钢的纯洁度 ,因而降低了钢的物理性能和机械性能。三者的关系式为 :Alt(全铝 ) =Als(酸溶铝 ) 酸不溶铝。由于炼钢全连铸工艺的普及 ,对钢中不同状态的铝的分析非常重要。连铸在线分析…     

脱铝丝光沸石的吸附性能研究

丝光沸石是优良的吸附剂和工业生产对二甲苯的实用催化剂。脱铝是使丝光沸石改性的有效方法。Chen报道了脱铝丝光沸石对环己烷的吸附量在硅铝比为15～50范围内随硅铝比增加而减少,而在50～90范围内变化很小。张红浪等用高温水蒸气处理结合酸洗的方法脱铝,得到不同硅铝比的丝光沸石,并研究了脱铝对其结构、酸性和催化性能的影响。本     

金属铝燃料电池的研究

铝是一种丰富廉价的有色金属，金属铝电池作为一种新型燃料电池，具有低成本、无毒害、高功率、高能量密度等优点。本文简述了金属铝电池的工作原理，并对铝阳极、空气阴极、催化剂、电解液和铝燃料电池的应用等方面的研究概况进行了叙述。     

由烷氧铝合成有机铝聚合物及其主要应用

本文就从烷氧铝合成有机铝聚合物的方法及有机铝聚合物的分类,作较详细的综合评述,并对其主要的应用作归纳和总结。     

不同方法处理的脱铝Y沸石的结构特征研究

用~(29)Si MAS NMR、~(27)Al MAS NMR、XRD及IR等方法对4种不同脱铝方法处理的USY、SSY、US-SSY和DAY的微观结构进行了研究,结合脱铝方法讨论了骨架硅铝的分布以及非骨架硅铝和羟基空穴等的形成和含量不同的原因.发现不同脱铝方法可导致骨架上不同Si(nAl)单元的脱除.XRD结果表明,SSY经进一步高温水蒸汽处理得到的US-SSY的相对结晶度可高达97％.脱铝后,微孔保留愈多,二次孔越少,相对结晶度愈高.最后对~(29)Si MAS NMR、XRD和IR3种测定骨架单胞铝(N_(Al))_F的结果进行了比较.     

金属铝燃料电池的研究

铝是一种丰富廉价的有色金属,金属铝电池作为一种新型燃料电池,具有低成本、无毒害、高功率、高能量密度等优点.本文简述了金属铝电池的工作原理,并对铝阳极、空气阴极、催化剂、电解液和铝燃料电池的应用等方面的研究概况进行了叙述.     

The habit of the pipe: a layperson’s view of the periodic table

Foundations of Chemistry - The Periodic Table of Elements is one of the greatest achievements of the human intellect but is far from a finished work. Generations of chemists and physicists...     

在儿童生长发育中铅的危害与锌的作用

综述了在儿童生长发育中铅的危害与锌的作用。认为铅中毒和锌缺乏将严重影响儿童的生长发育。铅对儿童是以中枢神经系统损坏为主,中构神经毒性最普遍的表现形式是智力和行为的异常。锌被誉为“生命之花”,在人的机体内具有极其重要的生理和生化功能,缺锌儿童发育迟缓、智力差、免疫力低下、食欲不振等。而且,锌能够减少组织中铅的蓄积和铅毒性作用的影响,补锌能有效降低人体铅的含量。葡萄糖酸是唯一被列入非处方药（OTC）目录的理想的有机锌补充剂。     

硅铝拮抗作用及铝吸收的PH值负相关效应

铝与生命体不相容，铝在人体中蓄积会导致老年性痴呆症等一系列脑疾患，肾功能不全者，铝更易蓄积，自然界发命通过碱性ＰＨ值及必不可少的硅酸根离子与Ａｌ＾３＋形成Ｓｉ／Ａｌ比为０．５的稳定的管式结构的羟基铝硅酸盐从而缓冲抗铝的蓄积和中毒。生命体还能通过突变、自然选择、自组织潜能行为发展自身排泄铝的解毒机构和体内平衡保护机制。     

Synthetic and structural carboxylate chemistry of neurotoxic aluminum in relevance to human diseases

The contact of Al(III) with biological components in human physiology has increased significantly over the years, due to a number of factors, prominent among which stands the rapid acidification of the environment and the concomitant introduction of that abundant metal ion in human biological fluids. As a result, pathophysiological aberrations in humans have arisen due to Al(III) (neuro)toxicity. Among the efforts targeting the elucidation of the factors responsible for Al(III) toxicity is the exploration of the requisite Al(III)-carboxylate chemistry in aqueous media, and its relevance to soluble, potentially bioavailable species capable of exerting toxic effects. A detailed synthetic, structural, and spectroscopic account of the Al(III)-carboxylate complexes, purported to exist as components in aqueous Al(III)-carboxylic acid speciation, is presented. The structures described are classified as mononuclear, dinuclear, trinuclear, tetranuclear, and polynuclear species, arising from various aqueous and non-aqueous Al(III)-carboxylate ligand reactions. Moreover, the solution chemistry and kinetic behavior of the so far reported complexes is given, with the specific aim of comparing their solid state and solution chemical and structural properties. In this sense, a comprehensive picture on the Al(III) speciation, in the presence of various physiological or biologically relevant carboxylate ligands, appears to emerge, which is expected to contribute to the understanding of Al(III) (neuro)toxicity and its consequence(s) in a multitude of human diseases. Carboxylate containing low and high molecular mass components stand prominent in their chemical preference to react with Al(III) in biological fluids. In this context, factors considered to influence the aqueous low molecular mass Al(III)-carboxylate chemistry, thus affecting the solubility and possibly the bioavailability of the resulting species, are discussed as potential research links to the ultimate manifestation of Al(III) toxicity at the cellular level.     

交联型温度/pH双敏水凝胶的设计与制备

刺激响应型水凝胶是其结构和性能随环境条件的变化而发生改变的一类智能高分子材料。由于温度和pH值是生物和化学系统的两个重要因素,也是人体的重要生理指标,因此温度/pH双重响应型水凝胶的制备及其在医药领域的应用研究具有重要的理论和现实意义。论文综述了近年来国内外温度/pH双敏水凝胶的设计与制备方法,并对其制备与应用的发展方向进行展望。     

Photoelectron spectroscopy and Ab initio study of the structure and bonding of Al7N- and Al7N

The electronic and geometrical structures of Al7N- are investigated using photoelectron spectroscopy and ab initio calculations. Photoelectron spectra of Al7N- have been obtained at three photon energies with six resolved spectral features at 193 nm. The spectral features of Al7N- are relatively broad, in particular for the ground state transition, indicating a large geometrical change from the ground state of Al7N- to that of Al7N. The ground state vertical detachment energy is measured to be 2.71 eV, whereas only an upper limit of approximately 1.9 eV can be estimated for the ground state adiabatic detachment energy due to the broad detachment band. Global minimum searches for A7N- and Al7N are performed using several theoretical methods. Vertical electron detachment energies are calculated using three different methods for the lowest energy structure and compared with the experimental data. Calculated results are in excellent agreement with the experimental data. The global minimum structure of Al7N- is found to possess C3v symmetry, which can be viewed as an Al atom capping a face of a N-centered Al6N octahedron. In the ground state of Al7N, however, the capping Al atom is pushed inward with the three adjacent Al-Al distances being stretched outward. Thus, even though Al7N still possesses C3v symmetry, it is better viewed as a N-coordinated by seven Al atoms in a cage-like structure. The chemical bonding in Al7N- is discussed on the basis of molecular orbital and natural bond analysis.     

铝的毒性作用对铁、钙和镁生理功能的影响及相关机理的研究概况

本文综述了近年来铝的毒性作用对铁、钙和镁生理功能的影响及相关机理的研究概况.并讨论了铝在阿尔茨海默氏病(Alzhmers disease, AD),帕金森氏病(Parkinson's disease, PD)及透析病中毒性作用机理.引用文献50篇.     

RgCo双金属催化剂的研究IV. Rh2Co2/Al2O3上的吸附中心类型及吸附性能

利用CO和NO作为双探针分子对Rh2Co2/Al2O3的吸附中心类型和吸附性能进行了详细的研究。结果表明Rh2Co2/Al2O3上存在Rh上的孪生和桥式CO吸附中心以及Co上的线式CO吸附中心。其中Rh上的孪生和桥式CO吸附中心对CO和NO的吸附性能与Rh4/Al2O3上的孪生和桥式CO中心相似。Co上的线式CO吸附中心以预吸附的CO能被NO取代, 预吸附的NO不能被CO取代而区别于Rh4/Al2O3上的Rh的线式CO吸附中心; 又以既能吸附CO又能吸附NO而不同于Co2/Al2O3和Rh+Co/Al2O3上的Co中心。与母体簇的结构相关联, 表明H2还原后的Rh2Co2/Al2O3上Rh2Co2(CO)12簇结构仍保持, 且Rh-Co相互作用强。     

加氢脱硫催化剂各组分的相互作用与催化性能

石油化工生产中广泛使用的加氢脱硫催化剂往往是以v－A120。作为载体,Moo或WOs为主要活性组分,少量Nio或Coo为助剂的多组分负载型催化剂．由于它在生产中所起的重要作用,此类催化剂的研究一直受到科学工作者的关注．本文分别考察了几种不同组分的催化剂,研究了催化剂组分间的相互作用对活性组分的分散状态、还原性能以及加氢脱硫活性的影响,旨在为进一步改进催化剂的性能提供有益的信息．且实验部分Ni－MO体系催化剂样品是以银酸钦和硝酸镍及v－AI。0。为原料,采用浸渍方法制备．C。M。／AJ。0。和W－Ni／AJ。0。分别用硝酸钻…     

Structures and electronic properties of Al7x0,- and Al13 X1,2,12- clusters with X=F, Cl, and Br

The structures, binding energies, and electronic properties for Al7X, Al7X-, Al13X-, Al13X2-, and Al13X12- (X = F, Cl, Br) were studied at the B3LYP/6-311+G(2d,p) level. Among the systems studied, Al7 and Al13 clusters in Al7X and Al13X- reveal alkali-like and halogen-like superatom characters, respectively. Al7 can bind with one halogen atom to form a salt-like compound as Al7+delta-X-delta. Al13- can combine with one halogen atom to form a diatomic halogen anion Al13X-. However, when adding more halogens, the superatom structure would be destroyed, resulting in low-symmetry compounds with the center Al atom moving toward the cluster surface. The structures of Al13X1,2,12- (X = F, Cl, Br) are similar to those of X = I; however, their binding energies and electron structures are much different. In addition, the analyses of the calculated NBO charges show that Cl and Br have similar properties, but much different from F, when interacting with the Al clusters. The Al-Cl and Al-Br bonds have more covalent character in Al7X and Al13X2,12-, in contrast to the corresponding Al-F bond, which has prominent ionic character.