Development of an Undercoat Layer for Dental Porcelain

Composites are developed on the basis of feldspar and hydroxyapatite with fluorite additives suitable for making ceramic coating for dental prostheses with good camouflaging properties and shape stability. The mechanism of the coating formation and their physicochemical properties are investigated.     

镍活化双层镀镍屏蔽材料的设计

以聚酯纤维布为原料,用镍盐替代高昂的钯盐作为活化剂,采用微波法制备不同阻抗的镀镍导电纤维布;以平行铺层法制备成多层结构吸波材料。通过控制镀膜厚度,并优化铺层方案,达到较好的电磁屏蔽效果。     

苏丹六区地层岩性特征及分层依据

苏丹六区作为总公司海外勘探开发的重点项目之一，作业规模逐渐加大，研究力度在进一步加强，对区域地质层位及岩石特征的认识有助于下一步勘探开发作业，本文结合大量现场实际钻探结果，系统地对全区地层及岩性特征进行了总结。     

超高压管道失效模式及防护对策研究

通过分析反应管振动、开停工及生产牌号转换循环载荷、正常服役期间的压力和温度波动、伺服脉冲阀动作脉冲载荷以及乙烯超温分解反应等因素对超高压聚乙烯反应管自增强残余应力松弛的影响。指出乙烯超温分解是导致超高压聚乙烯反应管自增强残余应力松弛的主要原因,并给出了反应管外壁腐蚀损伤机理和夹套管的失效模式。提出了防止超高压聚乙烯反应管自增强残余应力松弛的对策,并指出应采取在制造过程中尽量消除反应管残余拉应力、改善冷却水水质及优化夹套管结构等措施,来有效防止腐蚀损伤的发生和提高夹套管冷却水的有效流动性,从而保证了超高压聚乙烯反应管安全、可靠、长周期的运行。     

The Static Failure of Adhesively Bonded Metal Laminate Structures: A Cohesive Zone Approach

Adhesively bonded metal laminates are used in aerospace applications to achieve low cost, light weight structures in the aerospace industry. Advanced structural adhesives are used to bond metal laminae to manufacture laminates, and to bond stringers to metal laminate skins. Understanding the failure behaviour of such bonded structures is important in order to provide optimal aircraft designs. In this paper, the static failure behaviour of adhesively bonded metal laminate joints is presented. A cohesive zone model was developed to predict their static failure behaviour. A traction–separation response was used for the adhesive material. Three joint configurations were considered: a doubler in bending, a doubler in tension and a laminated single lap. The backface strains and static failure loads obtained from experimental tests were used to validate the results from finite element modelling. The models were found to be in good agreement with experiments.     

先进复合材料在飞机结构中的应用

科学技术的进步让先进复合材料的运用范畴更为广泛,随着我国对飞机结构研发的重视,复合材料以其高强度、密度小的优势被运用到飞机结构当中,研发人员不断发掘先进复合材料的潜力,提升复合材料的耐高温性能和耐疲劳性能,以强化飞机材料结构。阐述了先进复合材料在飞机结构中的具体应用以及效益情况,期望能够阐明先进复合材料的发展新趋势。     

Prediction of the Structure of Sintered Bioactive Composite Materials for Dental Implants

Results of experimental studies of optimizing the process of sintering in bioactive composite materials based on a silicate matrix and hydroapatite are described. To estimate and predict the technological, mechanical, and biological properties of materials, a sinterability index is proposed, which is the ratio between the specific surface areas of the matrix and the filler. A functional correlation between the sinterability index and the content and granulometric composition of the filler is identified. Sintered composites can be used for intrabone dental implants.     

纳米材料在钢结构防火涂料中的应用及前景

针对近年来钢结构防火涂料的研究现状,提出了利用纳米材料优越的性质将其应用于钢结构防火涂料中这一新的研究思路。介绍了火灾条件下对钢结构构件的破坏机理,评述了防火涂料的基本原理,综述了利用纳米材料优越的性质在钢结构防火涂料中取得的科研成果。同时预期了钢结构防火涂料的发展方向,为防火涂料的进一步发展提供了理论和方法上的参考。     

浅谈纯碱厂泵用动密封失效原因及对策

通过对泵用动密封原理的介绍,分析了纯碱厂泵用动密封在应用过程中容易失效的原因,并提出了相应的对策。     

The Technological Basis for Extraction of Arsenic from Various Raw Materials

Theoretical Foundations of Chemical Engineering - The fundamentals of the technology to extract elemental arsenic from various raw materials, taking environmentally friendly treatment processes...     

丙烯酸酯类功能性单体在口腔粘接材料中的应用进展

20世纪60年代以来,丙烯酸酯类功能性单体在口腔粘接材料中的应用得到了迅速的发展,它们的使用提高了牙釉质、牙本质及牙用合金与树脂之间的粘接强度,简化了临床操作。本文将对这些丙烯酸酯类单体的研究开发及应用做一概述。     

氮化硅陶瓷牙科修复材料研究进展

氮化硅具有比氧化铝、氧化锆等牙科陶瓷修复材料更好的力学性能、化学稳定性和生物相容性,已经用于生物骨科修复.近年来陆续有学者将氮化硅陶瓷引入到牙科修复领域,文章在介绍氮化硅陶瓷性能特点的基础上,综述了氮化硅陶瓷牙科种植体、氮化硅桩核冠及氮化硅饰面瓷的研究进展,并展望了氮化硅在牙科修复领域的未来研究方向.     

客车涂装底层材料配套性分析

针对南方客户在使用我司客车一段时间后,车身涂层不同程度出现了起泡的质量问题,进行了现场查看,发现起泡位置在车身左右侧蒙皮,且发生在涂层最底层。初步分析原因是热镀锌板+阴极电泳漆+原子灰三者之间配套存在问题,通过热镀锌板+阴极电泳漆+原子灰三者之间的耐高温80℃配套试验,以及室外曝晒试验,得出镀锌板表面是否钝化、电泳漆膜致密程度和原子灰苯乙烯含量是造成涂层底层起泡的主要原因。为了控制涂层起泡问题,重新修订了我司原子灰、镀锌板、电泳漆的技术标准以及部分工艺文件。     

Dynamical Effects of the Oxide Layer in Aluminum Nanoenergetic Materials

Dynamical effects of the aluminum nanopowder oxide layer are investigated in nanoenergetic materials consisting of nitrocellulose (NC) oxidizer containing embedded ~ 60 nm diameter Al having thinner (2.5 nm) or thicker (6 nm) oxide layers. Following laser flash‐heating, a hot spot is formed near each Al particle. The mean distance of reaction propagation d_rxn from the hot spot through the nitrocellulose is determined with ~100 nm resolution. With 100 ps pulses a shock propagation mechanism is dominant, and with 10–25 ns pulses reaction a thermal explosion mechanism is dominant. When higher energy picosecond pulses are used, d_rxn is observed to be significantly increased with thicker oxide layers, but using nanosecond pulses d_rxn is slightly decreased with thicker oxide layers. This oxide layer enhancement of d_rxn with picosecond pulses is attributed to the thicker oxide layer confining the hot Al for several tens of picoseconds, resulting in a larger shock wave. This work supports the view of the oxide layer as deadweight for slower heating rate processes such as combustion, but it suggests a thicker oxide layer may be of some benefit for extremely high heating rate processes involved in detonation or high speed deflagration of nanoenergetic materials.     

等离子喷涂玄武岩粉体及其涂层制备研究

以玄武岩废料为主要原料制备了等离子喷涂用粉体材料,在金属表面制备了等离子涂层,分析了制备工艺对粉体性能的影响,采用颗粒形貌、颗粒分布、粉体流动性等指标评价了粉体性能,利用SEM、XRD等方法研究了涂层结构及组成,并分析了粉体性能、涂层结构等对涂层性能的影响.结果表明,经熔融、水冷处理工艺制备的玄武岩粉体具有较好的流动性和粒度分布,可以制备等离子涂层,涂层以非晶体结构为主,含有少量的晶体,涂层与基体结合较好.     

多裂缝压裂设计及其实施效果分析

水力压裂是当前油气开采工程中最重要的增产技术之一。从水力裂缝的几何形态上区分,水力压裂作业可能形成垂直裂缝或水平裂缝。而水平裂缝是石油工程在较浅地层中进行水力压裂作业时常见的裂缝形态,但是相对垂直裂缝所作的研究工作较少,由于缺乏水平裂缝压裂理论方面的研究,实际工程在压裂水平裂缝时受到很大困扰。本文则针对这一问题对水力压裂水平缝问题进行了系统的研究,并且得出一层多缝提高了储层动用程度,扩大了泄油范围,进而提高了采收率。     

树脂基复合材料在混凝土结构中的应用

本文详细介绍了树脂基复合材料（FRP）的组成材料，探讨了用于混凝土结构增强和加固的树脂基复合材料的成型工艺。在此基础上，讨论了树脂基复合材料，诸如纤维聚合物筋，纤维聚合物板和纤维聚合物锚 的性能和在混凝土结构的应用现状和前景。     

Insights on Ceramics as Dental Materials. Part I: Ceramic Material Types in Dentistry

Ceramics are widely used biomaterials in prosthetic dentistry due to their attractive clinical properties. They are aesthetically pleasing with their color, shade and luster, and they are chemically stable. The main constituents of dental ceramic are Si-based inorganic materials, such as feldspar, quartz, and silica. Traditional feldspar-based ceramics are also referred to as “Porcelain”. The crucial difference between a regular ceramic and a dental ceramic is the proportion of feldspar, quartz, and silica contained in the ceramic. A dental ceramic is a multiphase system, i.e. it contains a dispersed crystalline phase surrounded by a continuous amorphous phase (a glassy phase). Modern dental ceramics contain a higher proportion of the crystalline phase that significantly improves the biomechanical properties of ceramics. Examples of these high crystalline ceramics include lithium disilicate and zirconia.     

膨胀型钢结构防火涂料膨胀炭质层的研究

选取有机硅改性丙烯酸乳液为成膜材料,聚磷酸铵(APP)、三聚氰胺(MEL)、季戊四醇(PER)为阻燃体系,二氧化钛和凹凸棒石为颜填料,采用红外光谱仪、X射线衍射仪、元素分析仪和X射线荧光分析仪对自制的膨胀型钢结构防火涂料灼烧后的膨胀炭质层进行了研究,内层主要是无机物和有机盐的混合物,表层为无机物.