本文从三个方面对微注塑成型技术的发展状况进行概述,分别为微注塑机的相关知识、目前的关键技术和研究方向,微注塑模具的结构设计与制造的工艺方法,目前微注塑成型理论的研究内容和现状.希望对微注塑成型技术的研究提供一定的指导意义和参考价值.

在多机种协同作战中,场站保障资源配置对飞机的出动强度具有重要影响.在运用多类顾客多服务器的排队网络模型描述飞机多机种(型)出动回收过程的基础上,结合多类顾客平均值分析,建立场站保障资源边际优化模型并给出算法求解流程.通过解析计算,给出飞机多机种(型)出动强度和保障资源优化过程曲线以及出动强度与保障资源总费用间关系曲线,揭示出动强度随迭代次数及资源总费用的变化规律;最后将资源优化配置结果与经验配置进行比较.结果表明,与传统的经验配置相比,该模型在满足出动强度目标的前提下,能较好地降低资源总费用,有效提高保障资源配置水平.

简述了热喷涂陶瓷涂层的研究进展,介绍了目前常用的热喷涂陶瓷涂层中耐磨陶瓷涂层、耐蚀陶瓷涂层、热障陶瓷涂层、生物陶瓷涂层和压电陶瓷涂层的研究现状.

A micro-inj ection mold cavity is designed and manufactured.By the method of no back plate growing technology,the micro-inj ection mold cavity with micro-array structure,micro-inj ection gate,micro-exhaust passage,exhaust vent and polymer melt flow channel is directly manufactured on an alloy steel substrate applying overlay UV-LIGA technology and mask etching technology.The optical lithography parameter of SU-8 thick photoresist is optimized and the proposed fabrication process for 350μm SU-8 photoresist is given as follows:scraping photoresist by fixing the thickness of frame,prebaking by gradient heating-up and temperature rising every 5 ℃ from 65 ℃ to 85 ℃,at 85 ℃ for 5.5-6.0 h,UV contacting exposure with dose of 630 mJ/cm2 ,post-baking at 85 ℃ for 15 min and development for 20 min.The causes for generating nodules in the process of Ni micro-electroforming are analyzed,and the process parameter is improved by controlling current density and pH respectively under 3 A/dm2 and 3.8-4.4.As a result,the micro-injection mold cavity of good quality is gained successfully.

以《工程材料及机械制造基础》为例,探讨了实践性教学改革的基本思路、内容和方法.从改革和创新实验教学模式、改革和深化实习教学模式、积极开展第二课堂和课外实践活动等方面,分析了全方位、立体化、多形式的“多位一体”实践教学模式的构建.这些措施对于学员创新素质的培养和创新能力的提高具有重要意义.

船舶在集装箱码头的装卸作业时间是影响港口竞争力的重要因素,为缩短计划期内集装箱船舶在港口停留时间,以船舶在港时间和泊位空闲时间最小为目标,建立了泊位与装卸桥联合调度优化模型.通过对泊位调度与装卸桥分配相关联的问题进行系统分析,提出相邻的泊位之间共享装卸桥,将有限的装卸桥资源在船舶装卸任务间进行动态分配和排序,构建了整数规划模型,以提高泊位资源和装卸桥资源的利用率,从而最大限度地减少船舶的在港时间,并对所建模型设计了基于任务排序的染色体结构,考虑应急物资优先装卸规则,用遗传算法进行相应的求解.数值实验结果表明,泊位与装卸桥的联合调度比泊位与装卸桥的独立调度可有效提高集装箱码头的装卸效率,在满足应急船舶优先装卸的前提下,最小化船舶在港时间.

将商用纳米Al_2O_3与TiO_2粉末混合制浆，通过喷雾造粒技术重构成大颗粒纳米Al_2O_3-13％T102团聚粉体，然后采用不同加热温度进行烧结，制备用于热喷涂的纳米喂料。采用等离子喷涂技术沉积形成纳米涂层。利用XRD和SEM对纳米粉末和涂层的形貌、显微结构和晶相进行表征。结果表明，在烧结过程中纳米氧化铝没有发生相变，而纳米氧化钛则由锐钛矿相转变为金红石相；在等离子喷涂过程中，部分a—Al_2O_3发生熔化转变为y—Al_2O_3，且转变量与喷涂工艺参数有关；而TiO_2相只在较低喷涂工艺参数下存在衍射峰，在较高喷涂工艺参数下则以z—A1203＂Ti02固溶体存在；涂层在热处理过程中会发生y．A1203向a—A1203的转变，且有Ti02相析出。

Commercial nanosized alumina and titania particles were selected as raw materials to prepare the blended slurry with composition of Al2O3-13%TiO2 (mass fraction), which were reconstituted into micrometer-sized granules by spray drying, subsequently sintering at different temperatures to form nanostructured feedstock for thermal spraying, and then Al2O3-13%TiO2 nanocoatings were deposited by plasma spraying. The evolution of morphology, microstructure, and phase transformation of the agglomerated powder and as-sprayed coatings were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that Al2O3 retains the same α phase as the raw material during sintering, while TiO2 changes from anatase to rutile. During plasma spraying, some α-Al2O3 phases solidify to form metastable γ-Al2O3, and the volume fraction of α-Al2O3 decreases as CPSP increases. However, peaks of the TiO2 phase are not observed from the as-sprayed coatings except for the coatings sprayed at the lower CPSP. As the CPSP increases, nanostructured TiO2 is dissolved easily in γ-Al2O3 or χ-Al2O3·TiO2 phase. After heat treatment, γ-Al2O3 in the coatings transforms to α-Al2O3, and rutile is precipitated.

论述了物资装卸搬运设备编目研究的现实需求,比较分析了外军和我军现有物资装卸搬运设备分类体系,并在此基础上提出了新的物资装卸搬运设备分类体系.

随着以计算机为核心的多媒体技术运用于课堂教学中，一种崭新的教育模式应运而生，其突出地表现为课堂教学过程的构成发生了变化，即由传统的“教师一学生一教学内容”三要素变革为现代的“教师一学生一教学内容一现代教育技术”的四要素。如何合理运用现代媒体技术提高课堂教学质量和效率，活跃课堂气氛，培养学生的创新思维是当今课堂教学改革需研究的重要课题。

课堂教学是高校整个教学活动的中心环节.高校的课堂教学活动是帮助学生掌握知识、发展智力、形成能力,使其成为具有扎实的理论基础,系统的专业知识和基本技能,具有创造精神和实践能力的专门人才的基本途径之一.为了充分利用课堂教学,达到上述目的,每位大学教师都应该在课堂教学过程中利用课堂讨论教学法,调动学生在学习中的主观能动性,都应该以培养学生的学习能力、思维能力,培养学生的创新精神为课堂教学活动的最终目的.

Nanostructured Al2O3-13wt.% TiO2 coatings were prepared by plasma spraying using agglomerated nanocrystalline powders via a spray drying method. The as-sprayed coatings and their worn surface were characterized using scanning electron microscope (SEM). The tribological characteristics were evaluated on block-on-ring configuration. It is found that that the nanostructured coating exhibited a unique bimodal microstructure, which has an important influence on the tribological characteristics. The abrasive wear resistance of the nanocoatings are greatly improved compared with the conventional coatings, and the abrasive wear mechanism is also discussed.

实际韧性材料在承载过程中会产生塑性损伤,正确描述微观塑性损伤对材料性能及韧性断裂过程的影响,对评定材料的安全性以及使用的可靠性,具有重要的理论和现实意义.基于此,介绍了微观塑性损伤机理的发展过程及应用最广泛的微观塑性损伤模型.

本文阐述了在《工程材料及机制基础》课程教学中增设课程论文的意见及具体实施步骤。

Commercial nano-sized alumina and titania particles were selected to prepare the blended slurry with composition of Al2O3-13% TiO2,reconstituted into micrometer-sized granules by spray drying and subsequently sintered at different temperatures,and then nanostructured feedstock for thermal spraying was formed.The changes of phases,microstructure and grain size were investigated by X-ray diffraction（XRD）,scanning electron microscopy（SEM） and measuring apparent density.The nano-particle growth and densification behavior of the agglomerated nanocrystalline powder during sintering were analyzed and a grain growth model was established.The results show that sintering temperature of the agglomerated nanocrystalline powder suitable for thermal spraying should be controlled below 1100 ℃.

针对超高强度钢D406A的生产现状和装备条件,提出了电弧炉偏心炉底出钢、钢包精炼、真空脱气和电渣重熔的新冶炼工艺.通过化学成分和金相组织分析,力学性能、弯曲性能和表面裂纹断裂韧度测试,该钢的各项指标均符合国家军队标准,表明该工艺可行.该工艺使D406A钢种在没有双真空冶炼设备的情况下得以生产,从而可降低成本,缩短生产周期.

Nanostructured and conventional Al2O3-13%TiO2 coatings were deposited by atmosphere plasma spraying technique.The microstructure of the as-sprayed coatings was investigated using X-ray diffraction (XRD),scanning electronic microscope (SEM) and transmission electron microscopy (TEM).The thermal behavior of two types of coatings was studied by means of thermal shock and thermal flame punching tests.The results show that under the same experimental conditions,thermal shock resistance of nanostructured Al2O3-13%TiO2 coating is significantly better than that of conventional coating,which appears more remarkably with higher temperature.Plasma sprayed Al2O3-13%TiO2 coating can significantly improve the flame ablation resistance of steel plate,and the nanocoating provides a longer time of flame ablation resistance.

Nanostructured Al2OB3-13wt% TiO2 coatings were prepared by plasma spraying agglomerated nanocrystalline powders formed via spray drying method. The phase composition, microstructure, microhardness and fracture toughness of the coatings were investigated. It is found that the nanostructured coatings exhibited a unique bimodal microstructure consisting of two distinct regions: one of the regions is Fully Melted (FM) and solidified as lamellar structure, and the other is Partially Melted (PM) particulate microstructure with embedded nano or sub-micron particles retained from the starting powders. Furthermore, the percentage of PM region, which is proportional to unmelted alpha-Al2O3 nanoparticles, in the coatings can be controlled by the critical plasma spray parameter. Such a characteristic of blended microstructure of the coatings is clearly confirmed from a bimodal distribution of their mechanical properties. The Weibull statistical analysis shows that the microhardness and fracture toughness of the coatings present a bimodal distribution, the mean value and the dispersity of microhardness of PM region are lower than those of FM region, but the mean value and the dispersity of fracture toughness of PM region are both higher than those of FM region.

As a typical boride ceramics,WC ceramics have become a researched hot point because of its high melting point, good chemical stability,high hardness and good resistance to abrasion.The WC granule is in-situ synthesized during the reaction of the alloy powders employing the TIG powder surfacing.The microstructure and morphology of the tungsten carbide coating is observed and analyzed.The elements of both the coating and the substrate diffuse to each other.The excellent metallurgy bonding is formed between the coating and the substrate.The results of the thesis show that we can get good performance of high-temperature coating by heating with TIG, which provides a theoretical foundation for the industrial practical application of WC composite coating.