Influence of interfacial strength on the fracture toughness of glass-ceramic matrix composites

Nine kinds of glass-ceramic matrix composites with different compositions and interfacial strength (τ _s) were prepared. The influence of τ _s on the fracture toughness(K _1c) of composites was studied. It was discoved that, for the system no chemical reaction taking place at the interface, K _1c increased proportionally with τ _s increasing at the first stage, then decreased when τ _s reached a certain value. According to this result, a model of relationship between τ _s, thermal mismatch (Δα _r) and K _1c was built up. If a chemical reaction took place and a new phase was formed in the interface, the K _1c of composite was effected by the combination of τ _s, chemical bonding, radial interfacial stress and other factors. Project supported by the National Natural Science Foundation of China Synopsis of the first author Wang Lingsen, professor, born in 1938, current research field: special ceramic and ceramic matrix composite, etc.     

超级有限元法及高耸桁架结构的超级元列式

介绍了一种大型结构分析的新的数值方法超级有限元法。利用该方法可大大降低结构分析的计算工作量。本文推导了高耸桁架结构的超级元列式，可用于塔架等大型桁架结构的力学分析。算例说明这是一种实用的大型复杂结构分析的数值方法。     

提高VD脱氢效率的研究

分析了影响VD脱氢效率的众多因素,采取相应的措施后,基本上满足了对氢含量有要求的钢种的生产.     

Curvilinear lattice in chiral carbon nanotubes

In this paper, the energy bands of chiral-type single-walled carbon nanotubes are studied employing a new curvilinear lattice theory and its reciprocal lattice aided by the spherical triangle theory. In this theory, the notion of a distance law is introduced as a constraint to determine the electronic characteristics of carbon nanotubes. The chiral tubes are proven to be semiconducting or metallic, depending on the diameters and helical angles of the tubes. The distance law also predicts an uncertainty for the electronic characteristics of chiral tubes due to the metallic states tightly surrounding the semiconducting states on the direct lattice, and vice versa. Results predicted by the distance law agree well with theoretical calculations of the electron density of states and published measurements.     

浅谈建筑工程施工阶段的成本控制

建筑工程绝大部分成本支出发生在施工阶段,因此对施工阶段成本进行有效的分析和控制,可以更好地实现成本管理的目标,提高企业的盈利能力。本文针对当前我国建筑工程项目成本管理经验不足的现状,从项目角度出发,对如何控制建筑工程施工阶段的成本进行了研究。通过深入分析施工阶段成本失控的原因、依据和对象,提出了施工阶段成本控制的具体措施。     

Q型聚类分析在确定成矿脉岩中的应用——以桦甸大庙子-菜抢子金矿区为例

吉林桦甸大庙子-菜抢子金矿区脉岩十分发育,且与成矿关系密切。通过近两年对该矿区实际地质调查研究,并重新采集各矿床脉岩、矿石样品30件,以Au、Ag、Cu等8种成矿元素作为变量,用Q型聚类分析的相关系数法进行了统计计算,计算得出金-黄铁矿型矿体与辉绿岩、煌斑岩、花岗斑岩有关;金-多金属型矿体主要与二长花岗斑岩、闪长玢岩有关,并与实际地质调查认识一致。由此明确了本矿区随着岩浆由中性向酸性演化,成矿由贵金属向多金属矿化转变。并在空间上形成叠加．     

吉林延边金谷山金矿床地球化学特征

以金谷山金矿床的成矿地质特征为基础, 研究了区域地球化学场及异常特征、岩(矿)石微量元素地球化学特征.矿床位于金及其它成矿元素的高背景场中,与成矿有关的元素组合为Au-Sb-As,异常强度高,分带性明显;地层、岩浆岩、构造等地质单元的地球化学特征表明,成岩作用、构造作用与成矿作用关系密切.     

欧洲国家电转气发展现状及其对云南省电转气产业发展的启示

如何科学地调度能源,实现多种能源系统之间的协调互补,是每个国家共同追求的可持续发展目标,因此研究电转气工艺并使其达到商业化具有重要意义。对电转气工艺与发展现状进行了梳理,对现有和潜在的商业模式进行了分析,最后结合我国云南省的实际情况探讨了电转气产业在云南省发展的现实价值,并探讨了其发展路径。     

浅谈锅炉中的低温腐蚀和烟气脱硫

为提高火力发电厂锅炉的热效率,延长锅炉的使用寿命,保护环境,提出了低氧燃烧和烟气脱硫两种方案。