Investigation on Crystallization Kinetics of Zr-AI-Based Bulk Amorphous Alloys

Zr65Al10Ni10Cu15, Zr52.5Al10Ni10Cu15Be12.5 and Zr52.5Al10Ni14.6 Cu17.9Ti5bulk amorphous alloys were prepared by copper mould casting. The crystallization kinetics was measured by differential scanning calorimeter(DSC) with different heating rates, and the activation energy was calculated using Kissinger equation. The relationship between thermal stability and rate constant of crystallization reaction is discussed on the view of crystallization kinetics, and the effect of small atom Beryllium on thermal stability of bulk amorphous alloys is also studied.     

壳聚糖溶液性质的研究

将壳聚糖配制不同酸度、浓度的乙酸溶液及壳聚糖乙酸溶液添加抗坏血酸和双乙钠,测定了溶液粘度随浓度、酸度、添加剂和存放时间的变化情况.实验结果表明,壳聚糖的粘度随浓度增大而增大、随酸度增大而减小、随存放时间增加而减小;添加剂抗坏血酸和双乙酸钠均使壳聚糖乙酸溶液粘度迅速降低,但随存放时间变化的不大.     

苯-乙醇两相介质中制备的羧甲基纤维素水溶液粘性行为(英文)

研究在苯－乙醇体系中制备的有代表性羧甲基纤维素（ＣＭＣ）样品的水溶液粘性行为及取代度、分子量对粘度的影响,重点讨论了取代基沿分子链的分布及在Ｃ２、Ｃ３、Ｃ６位上的分布对粘度性质的影响．还考察了羧甲基纤维素样品的抗酸性、抗碱性及抗盐性,为ＣＭＣ的应用提供了理论依据．     

改性有机玻璃热性能的研究

采用甲基丙烯酸甲酯、甲基丙烯酸、苯乙烯及二乙烯苯组成四元共聚体系,通过本体聚合制备出一系列耐热透明有机玻璃板材。研究了各改性组分对共聚物热形变温度的影响,测定了共聚物的玻璃化温度,结果表明,苯乙烯用量２５－３０％,甲基丙烯酸１０－１２％,二乙烯苯１－２％时的改性效果较好。     

一种新型骨料散装机的结构设计与分析

针对现有骨料散装机控制方式落后、结构设计不合理等问题,设计一种带有旋转阀机构的自动骨料散装机。系统构建了散装机整体结构三维模型,采用有限元方法对旋转阀机构在最大载荷工况下进行仿真分析,发现阀芯结构强度冗余,对阀芯进行拓扑优化设计。在保证刚度性能的前提下,使阀芯质量从628.07 kg减轻到407.26 kg,质量减轻35.15%,实现了阀芯的轻量化设计,为旋转阀芯的设计提供一定参考。     

Preparation of AlN thin films for film bulk acoustic resonator application by radio frequency sputtering

Aluminum nitride （AlN） thin films with high c-axis orientation have been prepared on a glass substrate with an Al bottom electrode by radio frequency （RF） reactive magnetron sputtering. Based on the analysis of Berg＇s hysteresis model, the improved sputtering system is realized without a hysteresis effect. A new control method for rapidly depositing highly c-axis oriented AlN thin films is proposed. The N2 concentration could be controlled by observing the changes in cathode voltage, to realize the optimum processing condition where the target could be fixed stably in the transition region, and both stoichiometric film composition and a high deposition rate could be obtained. Under a 500 W RF power of a target with a 6 cm diameter, a substrate temperature of 450 ℃, a target-substrate distance of 60 mm and a N2 concentration of 25%, AlN thin film with preferential （002） orientation was deposited at 2.3 μm/h which is a much higher rate than previously achieved. Through X-ray diffraction （XRD） analysis, the full width at half maximum （FWHM） of AlN （002） was shown to be about 0.28°, which shows the good crystallinity and crystal orientation of AlN thin film. With other parameters held constant, any increase or decrease in N2 concentration results in an increase in the FWHM of AlN.     

站姿振动对血液粘度的影响

目的:探讨站姿振动和传统力量训练后,血液粘度的变化特征和生理学机制。方法:运动训练专业21名志愿者,在站姿振动或传统训练条件下,负重深蹲训练12周,测试血液粘度4次。结果:实验组的全血低切粘度、高频低振幅组的全血高切粘度、全血相对粘度和全血高切还原粘度明显增高,均与对照组差异显著。结论:站姿振动使血液粘度增大,其中高频低振幅振动的影响更早、更明显,应科学选择振动训练参数和提高医务监督能力。     

椭圆齿轮流量计误差校正

该文分析了流体的粘度对椭圆流量计测量精度的影响,并简述其误差校正方法,该方法对流量测量仪表精度校正具有普遍意义。     

粘度及流变性在实验教学中的应用

物理化学实验主要针对物质的性质进行表征,传统的粘度测定方法是用乌氏粘度计测定高聚物的粘度。为了增强专业特色,为了加强学生的综合素质、创新意识的培养,为了使实验更接近现代实验教学的要求,设计选用了先进的旋转粘度计测量物质的粘度及其流变性。     

复配型特稠原油降粘剂研究

文中优化了稠油、特稠油复配型降粘剂的组成配方 .实验表明 ,优化的复配型降粘剂较其单组分的降粘性能明显增强而非优化的复配型降粘剂甚至不及其某些单组分的降粘性能 ,说明复配型降粘剂组分间存在着配伍性和协同效应 .