由气水流场耦合求解圆板的垂直等速入水

为探讨气流对入水空泡的影响以及计算非定常空泡面上的压力分布，本文提出了一个用自由面和物面上的边值同时求解气、水流场的方法，对圆板垂直等速入水算例，获得了空泡深闭合的结果。空泡内压力在深闭合时的骤增趋势与实验一致。表明本方法用于计算存在自由面的二层不掺混不可压势流问题是有效的。     

基于有限元的发动机连杆衬套温挤压工艺参数优化

以锡青铜连杆衬套为研究对象,通过Deform-3D软件进行了数值模拟。利用单一因素工艺参数试验法和正交试验优化试验方法对发动机连杆衬套的温挤压过程进行了数值模拟分析,得到了摩擦因数、温挤压速度、温挤压温度等参数在温挤压过程中对挤压力、损伤值的影响规律和显著性影响。利用极差分析得到了两组最优的温挤压工艺参数,并通过数值模拟两组较优解对挤压力、损伤值的影响规律的对比,最终得到一组最优解,即摩擦因数为0.1、温挤压速度为5 mm·s-1、温挤压温度为700℃。根据连杆衬套温挤压试验验证了使用优化后的工艺参数能够制造出表面质量高的成形件。     

Chaotic Bayesian optimal prediction method and its application in hydrological time series

The embedding dimension and the number of nearest neighbors are very important parameters in the prediction of chaotic time series. To reduce the prediction errors and the uncertainties in the determination of the above parameters, a new chaos Bayesian optimal prediction method (CBOPM) is proposed by choosing optimal parameters in the local linear prediction method (LLPM) and improving the prediction accuracy with Bayesian theory. In the new method, the embedding dimension and the number of nearest neighbors are combined as a parameter set. The optimal parameters are selected by mean relative error (MRE) and correlation coefficient (CC) indices according to optimization criteria. Real hydrological time series are taken to examine the new method. The prediction results indicate that CBOPM can choose the optimal parameters adaptively in the prediction process. Compared with several LLPM models, the CBOPM has higher prediction accuracy in predicting hydrological time series.     

导电涂膜表面微米尺度内痕量CIO-浓度测定方法的研究

简述采用四电极体系,锁相相关测定系统及三维微控装置,测定了电解人造海水在导电涂膜表面微米尺度内痕量C10-浓度的分布,为导电防污涂料研究的关键技术确定导电涂膜表面产生痕量C10-浓度相对应的通电参数作致关重要技术准备。     

Effects of eccentricity,temperature, velocity,and polymer properties on solids compressibility in vane extruder

An experimental instrument is developed with a purpose to study solids compaction behaviors in vane extruder in a direct manner. The effects of eccentricity, temperature, velocity, and polymer properties on the compressibility of polymer solids are reported in terms of compaction coefficient as a function of rotor torque. The results show that a relatively larger eccentricity or a lower external temperature can bring a smaller compaction coefficient, which results in higher pressure in the solids conveying zone of the vane extruder. However, rotor velocities almost have no influence on the compaction coefficient under the same condition. In addition, a difference is observed between the effects of the semicrystalline polymers and the noncrystalline polymers on the compaction coefficient, which should be taken into consideration in vane extrusion processing operations. POLYM. ENG. SCI., 54:1403–1411, 2014. © 2013 Society of Plastics Engineers     

Pellicle formation,microbial succession and lactic acid utilisation during the aerobic deteriorating process of Sichuan pickle

The pellicles formation, microbial changes and lactic acid utilisation during the aerobic deterioration of Sichuan pickle were discussed in this study. By plate counting, chemical detection and HPLC analysis, the aerobic deterioration of Sichuan pickle was featured by microbial growth, pellicle formation, lactic acid decrease and pH elevation. Bacteria dominated in pellicles and the pellicles present morphological change from smooth to wrinkly along with the aerobic deteriorating process. Nine species of bacteria were identified and responsible for the pellicle formation. Combined with Lactobacillus plantarum, eight pellicle‐forming bacteria were the dominant lactic acid consuming organisms in deteriorating Sichuan pickle. Especially under the harsh acid condition of the early deteriorating period, Lb. plantarum, pellicle‐forming bacteria Bacillus amyloliquefaciens, B. subtilis and Citrobacter freundii participated in the pellicles, utilised lactic acid and increased the brine pH effectively. Sequence analysis of 16S rDNA libraries suggested that the resulting pH of 4.8–5.0 initiated the growth of more undesirable organisms, and the pellicle bacterial diversity changed greatly compared with that in the early deteriorating period. The study indicated the important role of pellicles in the initiation of Sichuan pickle's aerobic deterioration and enhanced our ability to understand and potentially control the aerobic deterioration.     

按体积法设计沥青混合料

随着道路交易量增加，轴载和轮胎压力的增大，沥青混合料级配设计方法也有必要更新。本文提出了一种新的沥青混合料设计方法－体积法。根据这种方法设计的沥青混合料粗集料含量高。室内试验和试验路结构表明这种混合料能够提高柔性路面抵抗高温变形的能力，减少低温开裂。当用作表面层时，还具有良好的表面构造和抗滑性及不透水性。     

钛合金亚β锻造与热处理组织与性能的研究

钛合金经不同锻造—热处理规范加工后,其显微组织的变化是比较复杂的,尤其是亚β锻造以后研获得的网篮组织的形态是多种多样的。本文研究的是TC6、TC11钛合金加热到高于β相变点及接近β相变温度开始进行的变形及在(α β)两相区终锻并经等温退火后,其显微组织的特殊变化,同时比较分析不同热处理后的组织一性能关系,为在生产实践中制订热加工工艺规范提供可靠的依据,以便充分挖掘钛合金性能方面的潜力。     

计算机辅助制定工时定额系统

本文阐述以我院为主开发的,人机会话式的计算机辅助制定工时定额系统。该系统在 APPLE-Ⅱ机上运行,用 BASIC 语言编写。本文介绍主要程序框图和相互之间的关系。采用该系统,可以显著地提高定额工作的效率,用计算机快速地制定出准确、统一的工时定额、系统操作简便,效益显著。     

直流数字电压表低量限检定线路的改进及测量不确定度评定

本文详细地叙述了利用YJV—1直流标准电压源作为信号源采用比较法检定直流数字电压表低量值时所存在的问题,并设计一种改进电路,同时按照JJF1059-1999《测量不确定度评定与表示》规范的要求,对上述方法中所阐述的直流数字电压表低量值部分示值误差测量结果的不确定度进行了评定。