焊缝表面缺陷激光扫描三维重构测量

为检测工件焊缝表面缺陷，采用点激光位移传感测距法和数据拟合技术进行焊缝表面缺陷检测试验研究. 首先采集缺陷表面轮廓数据点，利用高斯滤波对原始数据降噪处理. 再对处理后的数据点进行Delaunay三角剖分，使散乱点连接并结合其空间坐标重构出缺陷的三维模型. 结果表明，基于点激光位移传感测距技术及焊缝表面缺陷三维重构方法可以准确判断焊缝成形情况.     

A computer aided design method for car form and its application based on shape parameters

In the early design stage, automotive modeling should both meet the requirements of aesthetics and engineering. Therefore, a vehicle CAD (computer aided design) model that can be easily adjusted by feedbacks is necessary. Based on CE-Bézier surface, this paper presents a set of algorithms for parametric segmentation and fairing surface generation in a car model. This model is defined by a simplified automotive template and relevant control points, shape parameters and segmentation parameters, which can be modified to alter the car form efficiently. With this model and the corresponding adjustment method, more than fifty various vehicle models are established in this research according to different parameters. And two methods for calculating similarity index between car models are constructed, which are suitable for brand design trend analysis and modelling design decisionmaking.     

早强剂对固结粉胶凝材料混合骨料充填体强度的影响

为实现废石和固结粉胶凝材料在金川矿区充填采矿中的应用，首先开展了不同配比废石—棒磨砂混合骨料粒径级配分析，获得废石与棒磨砂配比为4∶6混合骨料的堆积密实度为0.635和泰波幂指数n为 0.591；然后，针对废石含量为10%~50%的混合骨料，分别开展了添加和不添加早强剂的固结粉胶结充填体强度试验。结果表明：充填体强度随着废石含量增加呈现先提高后降低趋势。当废石含量为40%，料浆浓度为 79%~81%时，不添加早强剂的固结粉胶结充填体3、7、28 d平均强度分别达到1.23、3.79、5.98 MPa，其早期强度低于矿山设计强度；添加早强剂时，胶结充填体3、7、28 d平均强度分别达到1.55、3.34、6.46 MPa， 满足金川矿区下向分层进路胶结充填采矿作业对胶结充填体强度的要求。由此确定，胶砂比1∶5、废石∶棒磨砂4∶6、浓度79%~81%、添加1%早强剂的固结粉胶凝材料混合骨料可在金川矿区推广应用。     

介孔分子硅剂改善茶浓缩膜结构特性应用研究

为有效提高功能性茶浓缩反渗透膜的回收效率和抗污性能,探究了3种介孔分子硅材料(MCM-41、SBA-15和MCFs)对浓缩膜面聚酰胺层聚合形成过程的结构影响。结果表明,添加质量分数0.02%经磺化预处理的MCM-41于间苯二胺水相可接枝酰氯基团,形成的聚酰胺结构层峰谷粗糙跨度仅为220 nm且交联紧致,膜抗拉伸强度增加37.8%;SBA-15和MCFs相膜面峰谷跨度达500~780 nm,横向褶皱和团聚,结构存在孔道塌陷;改性膜在3 h内对茶多酚、茶多糖、茶蛋白即可达到最大浓缩度,减少50%浓缩时间;MCM-41和SBA-15膜长时间运行的浓缩降率仅为2.8%~6.1%,48 h下降率比显示改性膜达标使用时长增加112.5%~137.5%,亲水性和抗污堵能力均大幅提升,可有效满足功能化茶浓缩精度。     

凉感纤维织物导热系数影响因素的探讨

采用普通涤纶、含1%云母颗粒的涤纶(1%云母/涤纶)以及含5%云母颗粒的涤纶(5%云母/涤纶)三种材质,上机纬密采用200根/10 cm、300根/10 cm、400根/10 cm,组织采用平纹、斜纹、缎纹试织试样。通过Hot Disk热常数分析仪,采用正交试验及极差、方差分析,研究了纤维材质、上机纬密、组织对凉感纤维织物导热系数的影响。结果表明:在试验设置变量范围内,纤维材质对导热系数的影响显著,上机纬密、组织对导热系数的影响高度显著,影响因素从大到小顺序为上机纬密>组织>纤维材质。     

基于射流冲击作用的舰机适配性数值分析与优化

准确分析和控制射流冲击对航母甲板环境的影响是新型喷气偏流板设计和布局的关键所在。为了确定射流冲击影响最小的偏流板布局，运用有限体积法，采用分区混合网格方案，结合雷诺时均纳维斯托克斯（RANS）方程和SST k-ω湍流模型对喷气偏流板在不同布局下的射流冲击效应进行三维数值模拟。选取舰载机双发动机全加力状态时喷气偏流板与发动机距离不同、喷气偏流板倾角不同共12种布局组合进行射流冲击效应的对比计算,计算结果显示了喷气偏流板各布局下的流场参数、传热特性、尾喷口温升、冲击力和力矩等分布规律。定性和定量分析了燃气射流冲击下温度场和速度场的危险区域，结果表明，偏流板与发动机距离5 m、偏流板倾角45°时的布局更有利于将燃气射流向上引导。在此基础上，基于倾角最小化原则及二次导流原理优化设计了一种导流隔热性能好、工作稳定性高的被动隔热式喷气偏流板装置。     

发动机尾气余热驱动的吸附式空调系统仿真与测试

针对在高太阳辐射地区，柴油车驾驶室内使用车载空调会增加车辆发动机的耗油量、降低柴油车经济效益的问题，搭建了一套由发动机尾气余热驱动的吸附式车载空调系统。系统由填充有氯化钙/氯化锰/硫化膨胀石墨复合吸附剂的吸附床、蒸发器、冷凝器、储液罐和阀门组成，使用氨作为制冷剂，利用车辆在行驶时接触到的自然风为吸附床冷却，在发动机尾气余热的驱动下，为驾驶室内提供连续的制冷效果。结合仿真和实验测试，对所设计系统的制冷性能进行了分析，仿真结果表明，系统最优循环时间为45 min，系统的理论平均制冷功率可达3.5 kW以上，系统COP处于0.2~0.25之间。实验结果表明，在230℃的尾气温度条件下，系统能产生3 kW的平均制冷量。在40℃环境温度条件下，系统在蒸发器进出口处的平均温差为6.5℃，平均制冷量为3.2 kW。     

A facile method for preparation of PGS@ZB‐N and gas‐sol alternating synergistic effect for fire resistance of EVA

Through the simple precipitation of palygorskite (PGS) by zinc borate (ZB) (to make PGS@ZB) and the decoration of PGS@ZB by dodecylamine (N), a novel organic‐inorganic@inorganic hybrid flame retardant of PGS@ZB‐N was prepared and was incorporated with ethylene vinyl acetate copolymer (EVA) to improve its flame retardance. The structure and morphology of PGS@ZB‐N were characterized by Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), and scanning electron microscopy (SEM), and it was confirmed that the PGS@ZB‐N hybrid had been successfully prepared. The flame retardancy and burning behavior of EVA/PGS@ZB‐N/EG (EG = expandable graphite) composite were studied through thermogravimetric analysis (TGA), limiting oxygen index (LOI), UL‐94 (by the vertical burning test), and cone calorimeter test (CCT) characterizations. The prepared EVA/PGS@ZB‐N/EG composite obtained an LOI value of 41.2% with the addition of 30 wt% PGS@ZB‐N/EG. It was found that EVA/PGS@ZB‐N/EG was protected through a gas phase and condensed phase alternating synergistic effect mechanism.     

Personalized broad learning system for facial expression

Multimedia Tools and Applications - Understanding human emotions through facial expressions is key enabling technology for interactive robots. Most approaches of facial expression recognition are...