Discovery of carbon-based strongest and hardest amorphous material

Carbon is one of the most fascinating elements due to its structurally diverse allotropic forms stemming from its bonding varieties (sp, sp² and sp³). Exploring new forms of carbon has been the eternal theme of scientific research. Herein, we report on amorphous (AM) carbon materials with a high fraction of sp³ bonding recovered from compression of fullerene C₆₀ under high pressure and high temperature, previously unexplored. Analysis of photoluminescence and absorption spectra demonstrates that they are semiconducting with a bandgap range of 1.5–2.2 eV, comparable to that of widely used AM silicon. Comprehensive mechanical tests demonstrate that synthesized AM-III carbon is the hardest and strongest AM material known to date, and can scratch diamond crystal and approach its strength. The produced AM carbon materials combine outstanding mechanical and electronic properties, and may potentially be used in photovoltaic applications that require ultrahigh strength and wear resistance.     

水泥陶瓷材料显微结构实验室分析方法

水泥陶瓷材料显微结构,不仅记录了制品生产过程的全部,而且也反映了制品的物理化学性能。水泥材料的显微结构研究,以C3S、C2S和中间相的形态、自形程度和相互交代关系为对象,陶瓷材料显微结构研究,以新生矿物相和骨料胶结物为对象。确定制品生成过程中的温度、压力、通氧条件的相对差别,进一步推断各生成环节的工艺失衡条件。用以指导材料制品的生产。     

SAP R/3物料管理中物料主数据的应用

介绍SAP R/3系统中物料主数据的重要性,着重强调物料主数据的编码规范管理,详细阐述R/3系统中物料主数据的各个视图和相应的常用字段,及其对企业业务操作的重要影响,同时简述物料主数据的转换策略.     

混凝土外加剂最适量的选定

本文以未确知数学理论为基础,阐述了其在混凝土外加剂用量上的应用。     

The material histories of food quality and composition

This article argues for material histories of food. In recent decades food historians have tended to emphasize the cultural factors in consumption, in addition to the already well-established social, political and economic perspectives, but what is still missing is the stuff in foodstuffs. With reference in particular to milk and wine, the suggestion here is that physical and chemical composition is a major influence in what we might call the biographies of particular items of food and drink. Product characteristics are rarely static for long and today's mass-produced bread is different from that of the past, but then so are the flour, the yeast, and the even the butter that is spread on it. Adulteration was a particularly interesting aspect of composition in the nineteenth century and was the key to the emergence of two different traditions of understanding and valuing food quality.     

材料科学文献中常见问题与规范化

从材料硬度、组分和温度的表示方法,元素符号或分子式的用法,显微照片的标尺设置等方面,指出了材料科学文献中常见的不规范的问题。分析了这些问题产生的原因,结合相关国家标准和规范,给出了恰当的处理方法。对科技文献的规范化和学术交流具有重要意义。     

岩土介质爆破地震波的传播特性分析

爆破震动波在岩土介质中的传播行为较为复杂;通过理论分析并将爆破地震的影响因素分为产生和传播过程两个方面,研究了爆破震动波的传递规律及其影响因素,为工程实践提供指导.     

我国轧制方法生产层状金属复合材料的研究现状

轧制是生产层状金属复合材料的主要手段,该方法价格低廉,性能可靠。文章综述了轧制方法生成异种金属复合板的方法工艺及相应机理,总结了国内应用最为广泛的碳钢-不锈钢复合板的轧制生产工艺的研究现状和发展方向。     

卷烟生产企业物资供应管理探析

物资供应管理是卷烟生产企业经营管理的重要内容。从卷烟生产企业物资供应管理的行业特殊性出发，分析了此类企业存在的3个关键性问题，并就问题提出了一些对策和建议，希望能给卷烟生产企业一些启发和帮助。     

组织培养技术在保护藏药材中的作用

应用植物组织培养生产药用植物,具有不受地区、季节与气候限制,便于工厂化生产等优势,同时组织培养中的细胞生长速度要比植物正常生长速度快,接近于分生组织的生长速度,因此利用组织培养手段快速繁殖药用植物以及藏药材种苗,或者利用组织培养或细胞培养手段直接生产药物便随之日益发展.这对于保护已经濒危和即将濒危的藏药材种质资源具有重大的现实意义,同时对于保护西藏特有的生态环境也会起到举足轻重的作用.     

Research advances in fracturing mechanism of amorphous materials

The fracture behavior of brittle materials is a timehonored problem. Archeologists discover that prehistoric people created their primitive tools using this behavior. During the Stone Age, for example, they made simple wooden butchery implements by taking advantage of a sharp edge caused by the brittle fracture on flint. According to archeologists, the application of brittle fracture to the tool-making was one of monumental inventions to mark the very beginning of human civilization.Afterwards, ancient potters succeeded in decorating their works by having the surface of pottery inlaid with cracks and fissures.     

浅谈加强卷烟材料供应商管理的重要性及其对策分析

在卷烟生产成本构成中,卷烟材料的消耗占据总体消耗相当大的一部分。随着市场竞争的日趋激烈,发展品牌,扩大生产规模,提高产品质量,降低生产成本,向管理要效益,提升企业核心竞争力已成为企业追求的目标。卷烟材料质量管理在卷烟工业企业质量体系管理中有着重要的地位,而加强卷烟材料供应商的管理对卷烟材料质量控制至关重要。文章通过供应商管理现状、供应商自身内部管理存在问题、卷烟材料质量隐患及缺陷对卷烟生产运行、产品质量及品牌生存发展等方面来阐述卷烟材料供应商管理的重要性,并进行了对策分析。