“有界”和“无界”

用马克思主义占领自然科学阵地,是科技战线实行无产阶级专政的一个重要方面。引导学生学习自然辩证法,以逐步形成辩证唯物主义的世界观和方法论,培养学生用马列主义、毛泽东思想分析问题和解决问题的能力,是化学教学的一项重要任务。这里刊登的两篇学习自然辩证法心得体会的短文,是四川省会东中学高七四级化学试卷的一部分。这样的答卷是旧中学所不能比拟的。因此,也是对教育界、科技界右倾翻案风一个有力的回击。     

“友”和“敌”

人体必需元素是人体健康之“友” ,不能缺乏 ,更不能没有 ,否则就使人患病 ;另一方面 ,也不能过多(从理论上来讲 ,任何必需元素都不能过多 ,但现实生活中 ,有一些元素并不存在由于过多而致病的问题 ) ,否则会化“友”为“敌” ,使人中毒 ,这类例子是很多的。例如食盐 ,井岗山时期 ,国民党反动派对红军实行封锁 ,把食盐也列为封资物资。电影《闪闪的红星》中潘冬子给红军送盐时 ,为了逃避敌人检查 ,把盐用水溶解浸湿棉衣 ,到达后再把棉衣中的盐水挤出来熬盐 ,可见食盐对于人体是多么必要。可是 ,过多吃食盐会导致高血压已是公认的事实 ,并为…     

“测定”与“检定”

本刊一九八二年第六期45页的标题“纸色谱法分离测定金属离子”中“测定（determination）”一词欠妥。在分析化学中“测定”只用于定量,不能用于定性的工作。按该文内容是定性的——金属离子的检定。计算比移值也不能算定量分析工作,而是为了定性之目的。     

“瘦肉精”

本文介绍了瘦肉精目前在社会上的危害情况,瘦肉精的组成、结构、性质和它作用于动 物的简要药理。陈述了人体瘦肉精中毒后的症状和处理措施。简述了瘦肉精的监管和测定。     

“活性中间体”与“过渡态”

活性中间体和过渡态是两个不同的概念。在许多有机化学反应中,从反应物到产物往往不是一步完成,而是经历若干步骤。在这些多步骤反应中会形成一些极不稳定的反应中间体。例如,烷烃卤代反应过程中生成的碳游离基,烯烃与卤化氢加成过程中生成的碳正离子以及芳烃亲电取代反应中生成的σ络合物—碳正离子中间体等等都是非常活泼的中间体,它们一般称为有机活性中间体。有机活性中间体除碳游离基、碳正离子外,还有碳负离子、碳烯、苯炔等等。这些活性中间体都有着共同的特征:它们都非常活泼,生成后立即与其它物质反应,存在时间很短暂。     

欧洲民族语言中的“炼金术”与“化学”

欧洲文艺复兴以后,早在拉丁语处于学术中心地位的时代,在法语、德语、英语等民族语言文献中就出现“炼金术”和“化学”2个不同的词语.但起初很长时间内这2个词语基本是同义语.18世纪以后,随着西方学术的“地方化”,欧洲民族语言逐渐取代拉丁语成为主要的学术语言.于此同时,“炼金术”与“化学”2个词有了明确的区别,并逐渐产生了2个不同的学科.本文简要考察了民族语言中“炼金术”与“化学”的起源和演变过程,并进一步说明,18世纪以后,现代化学与炼金术的分离是西方现代科学发展的一般特点:即与思辨哲学和神秘主义法术分离,走向学科的分化独立.     

“中庸”与“催化”随想

"中庸"是传统的中国智慧,由孔子提出,不断被他的追随者丰富."中庸"追求在各种矛盾中寻求平衡,并认为"过分"和"不及"都是不好的.对于一个成功的催化剂,反应物的吸附,既不能太强,也不能太弱.在这一点上,"催化"与"中庸"有极为相似之处.本文以孔子与他的学生对话开始,先讲了3个著名的"中庸"老故事,结合3个有"中庸"味道"催化"案例,最后得出:好的"催化",即是具有"中庸"味道的"催化".     

是“因”还是“果”?

先天性痴呆又叫先天愚型、白痴,是一种最常见的常染色体遗传病,患者智力低下,常呈伸舌样痴笑。这种患儿在新生中的发生率为15‰。统计表明,其发生率与婴儿母亲年龄有关;40岁以上孕妇新生婴儿,患儿出生率则上升到六十分之一,约为正常出生婴儿中患者的10倍。在细胞学上,除性...     

“镭”光四射

Radium is a radioactive metal element. In the early period of its discovery, it was abused due to the lack of understanding, which led to many tragedies. In this paper, in a self-reported tone and anthropomorphic way, the discovery and extensive application of radium is briefly reviewed.     

Dithiolodithiole as a Building Block for Conjugated Materials

The development of new conjugated organic materials for dyes, sensors, imaging, and flexible light emitting diodes, field‐effect transistors, and photovoltaics has largely relied upon assembling π‐conjugated molecules and polymers from a limited number of building blocks. The use of the dithiolodithiole heterocycle as a conjugated building block for organic materials is described. The resulting materials exhibit complimentary properties to widely used thiophene analogues, such as stronger donor characteristics, high crystallinity, and a decreased HOMO–LUMO gap. The dithiolodithiole (C₄S₄) motif is readily synthetically accessible using catalytic processes, and both the molecular and bulk properties of materials based on this building block can be tuned by judicious choice of substituents.     

碳基三维自支撑超级电容器电极材料研究进展

自支撑电极材料在超级电容器中有着广泛的应用. 碳材料具有结构多样、来源丰富、价格低廉以及性能稳定等优点,是构建三维自支撑电极材料的首选基底材料. 本文结合作者课题组的研究工作,从“由上而下”和“由下而上”两个方面,概述了设计、制备三维自支撑电极材料的常用方法及材料的电容性能,希望对开发利用天然可再生资源,制备高性能的自支撑电极材料及其在超级电容器材料中的应用有所帮助.     

Cellulose: fascinating biopolymer and sustainable raw material

As the most important skeletal component in plants, the polysaccharide cellulose is an almost inexhaustible polymeric raw material with fascinating structure and properties. Formed by the repeated connection of D-glucose building blocks, the highly functionalized, linear stiff-chain homopolymer is characterized by its hydrophilicity, chirality, biodegradability, broad chemical modifying capacity, and its formation of versatile semicrystalline fiber morphologies. In view of the considerable increase in interdisciplinary cellulose research and product development over the past decade worldwide, this paper assembles the current knowledge in the structure and chemistry of cellulose, and in the development of innovative cellulose esters and ethers for coatings, films, membranes, building materials, drilling techniques, pharmaceuticals, and foodstuffs. New frontiers, including environmentally friendly cellulose fiber technologies, bacterial cellulose biomaterials, and in-vitro syntheses of cellulose are highlighted together with future aims, strategies, and perspectives of cellulose research and its applications.     

先进材料的设计——网络拓扑方法

网络拓扑方法是新近在晶体工程中使用的一种直观有效的策略,它使复杂的晶体结构设计简化为分子拓扑结构的组建。本文介绍了这一方法的基本思路,以及它在设计组装各种光、电、磁、离子交换、催化等新型功能材料中的应用。     

Polymer Nanocomposites in Building,Construction

Nanotechnology is an enabling technology allowing to do new things in almost every conceivable area. Initial efforts to exploit nanoscience/nanotechnology development in the construction industry focused mainly on understanding phenomena and improving performance of existing materials. Recently, polymer nanocomposites started to be introduced in other areas like the construction industry.

Polymer nanocomposite field attracts considerable attention these days due to a variety of potential practical applications. They have offered a great opportunity in sustainable construction/green building application due to their efficiency and environmental protection. Their use in the construction industry is still less known outside the research area. This paper is a short review of recent studies done in this area, taking into account that some nano based materials are ready to be used by the construction industry. This review covers some studies done in the polymer nanocomposite applications in construction basic materials such as concrete, asphalt, thermal and sound insulation, adhesives, coatings, plastics and in energy.     

Functional organic materials based on polymerized liquid-crystal monomers: supramolecular hydrogen-bonded systems

Functional organic materials are of great interest for a variety of applications. To obtain precise functional properties, well-defined hierarchically ordered supramolecular materials are crucial. The self-assembly of liquid crystals has proven to be an extremely useful tool in the development of well-defined nanostructured materials. We have chosen the illustrative example of photopolymerizable hydrogen-bonding mesogens to show that a wide variety of functional materials can be made from a relatively simple set of building blocks. Upon mixing these compounds with other reactive mesogens, nematic, chiral nematic, and smectic or columnar liquid-crystalline phases can be formed that can be applied as actuators, sensors and responsive reflectors, and nanoporous membranes, respectively.     

The supramolecular chemistry of organic-inorganic hybrid materials

The combination of nanomaterials as solid supports and supramolecular concepts has led to the development of hybrid materials with improved functionalities. These "hetero-supramolecular" ideas provide a means of bridging the gap between molecular chemistry, materials sciences, and nanotechnology. In recent years, relevant examples have been reported on functional aspects, such as enhanced recognition and sensing by using molecules on preorganized surfaces, the reversible building of nanometer-sized networks and 3D architectures, as well as biomimetic and gated chemistry in hybrid nanomaterials for the development of advanced functional protocols in three-dimensional frameworks. This approach allows the fine-tuning of the properties of nanomaterials and offers new perspectives for the application of supramolecular concepts.     

Calorimetry of building materials

Classical adiabatic methods for measuring specific heat in a wide temperature range are very suitable for homogeneous, well defined materials. However, measurements on inhomogeneous materials require large samples, which makes using of adiabatic treatments extremely expensive. In this paper, a nonadiabatic method for determining the specific heat of inhomogeneous building materials within the wide temperature range of ?30 to 1200°C is presented. The method is relatively simple, very cheap, and sufficiently accurate for use with building materials. Tests of the new developed method on two typical building materials, concrete and basalt fibreboards, demonstrate the method's applicability to practical measurements.     

Phenolic Building Blocks for the Assembly of Functional Materials

Phenolic materials have long been known for their use in inks, wood coatings, and leather tanning. However, there has recently been a renewed interest in engineering advanced materials from phenolic building blocks. The intrinsic properties of phenolic compounds, such as metal chelation, hydrogen bonding, pH responsiveness, redox potentials, radical scavenging, polymerization, and light absorbance, have made them a distinct class of structural motifs for the synthesis of functional materials. Materials prepared from phenolic compounds often retain many of these useful properties with synergistic effects in applications ranging from catalysis to biomedicine. This Review provides an overview of the diverse functional materials that can be prepared from natural and synthetic phenolic building blocks, as well as their applications.     

有机相变材料的发展及在纺织领域的应用

相变材料因为其优良的热性能,被广泛应用于纺织品、航空航天、交通运输、农业、国防、建材、太阳能系统和医疗设备等领域。近年来,开发应用新型相变材料已经成为研究热点。本文首先概括介绍了相变材料发展进程,着重介绍了有机相变材料,包括它的分类、性能和应用。详细介绍了有机相变材料在纺织行业的应用,以及对调温纺织品测试手段的研究和建立的相关数学模型的建立。