Materials Literature
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Halloysite is a 1:1 aluminosilicate clay mineral. Usually, it has a tubular crystal shape, a unique structure and significant solute entrapment properties. As a result, halloysite can retain a variety of substances inside its lumen for different purposes and uses. In this study, halloysite nanotubes were investigated…
The mechanical properties of any materials are highly dependent on defects and defect interactions. To improve the mechanical performance and design better materials, it is critical to understand the way defects influence the mechanical properties fundamentally. Transmission electron microscope (TEM) is a powerful too…
The study of single lap adhesive joints has been done to find out the mechanical strengths of variable overlap length, establishing maximum load bearing capacity using two component epoxy resin as binding material. The engineering properties studied are joint tensile strength and adhesive shear strength. The dimension…
为了研究不同重结晶工艺对1, 1′-二羟基-5, 5′-联四唑二羟胺盐(HATO, TKX-50) 热性能和机械感度的影响, 分别采用降温法、溶剂-非溶剂法, 制备了6种不同粒径和晶体形貌的HATO样品。利用激光粒度仪和扫描电镜对不同重结晶工艺所得HATO样品的粒度和形貌进行了表征。利用差示扫描量热仪(DSC)对其热分解性能进行了分析。按GJB772A-1997方法对其撞击、摩擦感度进行了测试。结果表明, 不添加表面活性剂, 利用降温重结晶制备的HATO样品其粒度最大(d50=196.5 μm)且晶体表面光滑、形状规则, 表现出最高的分解温度及较低的机械感度, 其分解峰温为249.1 ℃, 撞击感度、摩擦感度分别为8%、20%。
以六氢咪唑[4, 5-d]咪唑-2(1H)-亚胺为原料, 通过三个阶段硝化反应合成了一种新型多环氮杂环含能化合物: N-1, 4, 6-三硝基六氢咪唑[4, 5-d]咪唑-2(1H)-亚硝胺(TNINA), 总收率55%。采用红外光谱(IR)、核磁共振(NMR)、质谱(MS)对目标产物以及中间体进行了表征, 同时研究了时间、温度、乙酸酐与硝酸体积比等因素对第三阶段硝化反应的影响。利用热重分析(TG)和差示扫描量热仪(DSC)研究了TNINA的热性能, DSC结果显示其热分解温度为214.4 ℃, 且放热过程瞬间完成。用Monte-Carlo方法估算TNINA的理论密度为1.91 g·cm-3, 真密度仪测得其密度为1.89 g·c…
为了获得1-三硝甲基-3-硝基-1, 2, 4-三唑(TNMNT)的晶体结构并对其性能进行预估, 以3-硝基-1, 2, 4-三唑为原料, 通过取代、硝化反应合成出了TNMNT, 收率为62%, 以无水乙醇为溶剂, 用溶剂蒸发法培养得到纯的TNMNT单晶, 并采用核磁共振谱、红外光谱与X-射线单晶衍射仪进行了结构表征。用DSC-TG法分析了热稳定性。用Gaussian 09 and EXPLO5(V6.02) 程序分别计算了生成焓和爆轰参数。结果表明: TNMNT晶体属于单斜晶系, 空间群P21/c, 晶体参数为a=6.643(3)A, b=20.494(7)A, c=6.698(3)A, β=94.225(9)°, V=909.…
在氨基化改性的四氧化三铁（Fe 3 O 4 ）纳米粒子表面引发 N -羧酸酐 L -谷氨酸苄酯（BLG-NCA）开环聚合，制得四氧化三铁/聚 L -谷氨酸苄酯（PBLG）复合材料（Fe 3 O 4 -g-PBLG）. 改变单体和引发剂比例可以调控Fe 3 O 4 -g-PBLG的接枝率，采用热失重分析（TGA）测得实际接枝率分别为66.36%，79.66%和89.52%. 通过双乳液挥发法制备磁性Fe 3 O 4 -g-PBLG多孔微载体，其中接枝率为89.52%的微载体密度为1.034 g/mL，孔隙率为92.57%，粒径为200~300 μm，孔径为40~50 μm，保水率为370%~400%. 同时Fe 3 O 4 -g-P…
The predictive utility of a damage model depends heavily on its particular choice of a damage variable, which serves as a macroscopic approximation in describing the underlying micromechanical processes of microdefects. In the case of spatially perfectly randomly distributed microcracks or microvoids in all directions…
基于静态腐蚀试验和Arrhenius公式，探讨了缓蚀剂1,2,4-三唑在铜晶圆表面的吸附机制，分析了其对铜晶圆表面化学反应活化能的影响；结合CMP试验，阐释了BTA和1,2,4-三唑两种缓蚀剂对CMP材料去除速率的影响. 结果表明：在酸性抛光液中，缓蚀剂1,2,4-三唑主要存在两种缓蚀机制：一是在铜表面形成吸附膜Cu:(1,2,4-TAH) ads ，二是形成聚合物膜Cu(1,2,4-TA) 2 . CMP过程中化学反应活化能的降低量不随抛光液中1,2,4-三唑的含量而变化. 但是相对于BTA，使用含有1,2,4-三唑的抛光液时CMP过程中晶圆表面的化学反应活化能降低量较大，表明机械促进化学作用较强. 本研究结果为CMP过程中抛光…
为了提高GaN基LED的发光效率，设计了一种新型LED模型，该模型主要包括Ag光栅，氧化铟锡过渡层和P-GaN光栅。首先阐述了利用该结构激发表面等离子体从而改善LED发光特性的原理，讨论了该模型的加工工艺与制作过程。基于COMSOL软件，利用有限元法对本文提出的LED模型进行了仿真分析，得出该模型在不同结构参数下，归一化辐射功率与归一化损耗功率随波长的变化规律以及电场分布情况。仿真结果表明，在ITO过渡层厚度为55 nm，周期为270 nm，占空比为0.5时，所设计的GaN基LED模型的发光强度较普通LED提高近30倍，这一结果为研制高性能GaN基LED提供了可靠基础。
采用高通量测序法从单环刺螠基因组中开发微卫星标记，并通过一个秦皇岛单环刺螠野生群体对其进行多态性评价，利用获得的多态性引物对秦皇岛、烟台、潍坊、青岛、大连5个不同海区的野生单环刺螠群体进行了遗传多样性及遗传结构分析。结果表明：本实验设计的50个微卫星标记能稳定扩增的有38个，其中22个微卫星位点在5个群体中均表现为高多态性，等位基因数（Na）介于24-44之间，多态信息含量（PIC）介于0.921-0.967之间。5个群体总的平均有效等位基因数（Ne）范围为6.629-8.850，平均观测杂合度（Ho）和平均期望杂合度（He）范围分别为0.790-0.912、0.851-0.896，大连群体的杂合度最大（He=0.8962），潍坊…
Surface modification of polymers can lead to changes of properties such as surface wettability, adhesion, bioactivity and biocompatibility. Here, a long chain, low surface energy monomer, docecyl methacrylate (DMA), which is difficult to graft by chemical mean was grafted onto three different types of ‘Engages’ (a pol…
In chapters 4–9, we studied the statistics of strength and lifetime of quasibrittle structures. The underlying approach was anchored by the weakest-link theory, in which the structure is statistically modeled as a chain of representative volume elements (RVEs). Because the size of material inhomogenieties (or, equival…
The use of water soluble adhesives of both natural and synthetic origin, unlike adhesives on organic basis, contributes to solving problems of environmental protection and improvement of sanitary conditions. Therefore the purpose of the research is to make modifications of soluble polyvinyl alcohol adhesive compositio…
keV Ga to reduce contact resistivity -I-V properties ............ 2.6) Correlating I-V properties with defect distributions using DRCLS ...........
Being one of the largest transmitters of natural gas, Ukraine has pipeline systems technologically connected with similar pipelines in Russia, Belarus, Moldova, Romania, Hungary, Slovakia and Poland, and through them with gas pipelines throughout European continent. The urgency of studying of the influence of pH on th…
In many engineering applications, the risky overload would not occur right at the first load application. This chapter, based mostly on Salviato, Kirane, & Bažant (2014), deals with the residual strength of a structure at an accidental sudden overload that occurs later, after a period of sustained load high enough to…
As already explained in Chapters 1 to 3, there are two basic types of quasibrittle failure and size effect, types 1 and 2. They have different large-size asymptotes of the size effect and different statistical contributions of material randomness. Type 1 (Bažant & Li 1995 b ; Bažant 1997; Bažant & Novák 2000 a , 2000…
Розроблено полімерні композиційні матеріали на основі конструкційного термопласту – полікапроаміду і модифікованого полівініловим спиртом та полівінілпіролідоном Ni-вмісного полімер-силікатного наповнювача. Виявлено, що введення наповнювача призводить до зміни морфології розроблених композитів, зокрема, зростає ступін…
V této bakalářské práci, která je součástí projektu RadioRoSo, se věnujeme analýze odpadu z Magnoxových jaderných elektráren. Tyto elektrárny se nacházely především ve Velké Británii a byly provozovány v letech 1956 až 2015. Analyzovaný odpad se skládá především z kusů slitiny Magnox AL80. Dále v něm můžeme nalézt pru…