醋酸溶液提取蓝莓花色苷工艺的研究

蓝莓花色苷具有抗氧化、增加人眼视力等多种生理功能。该文以蓝莓为原料,对醋酸溶液提取蓝莓花色苷工艺进行了研究。结果表明:蓝莓花色苷最佳提取工艺条件:醋酸浓度20%,提取温度40℃,提取时间1h,料液比1∶10,提取2次。蓝莓花色苷提取率为92.8%。     

发动机油失效分析的一个思路

随着发动机技术的进步,对发动机油的要求越来越高,运用FMEA指导发动机油的失效分析。对于潜在的故障分析及预防故障发生,要分析发动机润滑系统的机制、润滑油对发动机的保护机制、换油方式的影响,关注润滑系工作的有效性。从润滑油的功能、发动机油失效的危害、发动机油的适用性等方面分析发动机油对发动机的保护机制。从发动机油的质量变化原因、发动机油失效模式、发动机油失效原因等方面分析发动机油的失效。综合判断发动机油的有效性,运用因果关系图分析发动机油失效模式,全面分析发动机油失效的原因。     

食品机械中自动切割装置的研发

随着食品工业的发展,食品机械的研发也有新的进展.本文概述了食品机械的发展状况,重点分析我国食品机械中自动切割装置的研究现状及存在问题,指出今后我国自动切割装置研发的重点方向.     

我国膨化食品行业质量安全问题分析及发展趋势

主要从膨化食品原辅料、加工过程、包装、贮藏及运输等环节对其可能产生的质量安全问题进行分析说明,并就膨化食品加工业未来发展趋势进行阐述。     

Adaptive gait detection based on foot-mounted inertial sensors and multi-sensor fusion

Gait detection plays an important role in areas where spatial-temporal gait parameters are needed. Inertial sensors are now sufficiently small in size and light in weight for collection of human gait data with body sensor networks (BSNs). However, gait detection methods usually rely on careful sensor alignment and a set of rule-based thresholds, which are brittle or difficult to implement. This paper presents an adaptive method for gait detection, which models human gait with a hidden Markov model (HMM), and employs a neural network (NN) to deal with the raw measurements and feed the HMM with classifications. Six gait events are involved for a detailed analysis, i.e., heel strike, foot flat, mid-stance, heel off, toe off, and mid-swing. In order to obtain enough gait data for training a gait model, the gait events are labeled by a rule-based detection method, in which the predefined rules are verified with an optical motion capture system. Experiments were conducted by nine subjects, based on a dual-sensor configuration with one sensor on each foot. Detection performance is quantified using metrics of accuracy, sensitivity and specificity, and the averaged performance values are 98.11%, 94.32% and 98.86% respectively with a timing error less than 2.5 ms.     

波纹管球阀的研究

分析了波纹管截止阀和闸阀在设计和运行中的问题，介绍了波纹管球阀的特点，通过对比．给出了用波纹管球阀取代截止阀和闸阀的必要性及发展前景。     

Theoretical and experimental analysis on super precision grinding of monocrystal silicon

Through investigating the diamond-silicon grinding system, the grinding mechanism, including chip removal and subsurface damage, is discussed with the aid of the molecular dynamics (MD) approach and grinding experiments. Based on MD simulation, nanometric-grinding mechanism is analyzed from the viewpoint of instantaneous distribution of atoms, grinding force, and the potential energy between atoms and the profile of the groove. The simulation results show that some silicon atoms are deformed and piled up in front and on two sides of the abrasive surface because of the extrusion and cutting. When the energy in silicon lattice reaches its maximum value, the bonds of silicon atoms are broken and the material is removed. With the advancement of the abrasive, the silicon lattice under the abrasive surface is fractured, and then the amorphous layers are formed and propagated, which causes the subsurface damage. At the same time, some amorphous atoms are reconstructed and the degenerating layer of the machined surface is formed. Besides, the recovery of elatstic deformation occurs in the machined surface of the workpiece. In addition, the grinding experiment and profile detection with the aid of the measurement for 3D profiling are performed to verify the simulation results. The good agreement in the profile of the groove between the experimental value and the simulating value shows that MD simulation is very effective and reliable, and successful to fulfill the investigation on nanometric machining mechanism.     

改进遗传算法整定自抗扰控制器参数及应用

非线性自抗扰控制器策略(ADRC)耦合参数众多,单一机制优化算法在进行参数整定时易陷入局部最优解,极大地降低了自抗扰控制器的控制精度。针对此问题,该文提出了一种改进遗传算法(KFC-2PMGA)进行自抗扰控制器参数整定,将核模糊聚类算法应用到遗传算法双种群划分中,并针对聚类所得双种群,分别采用不同的自适应交叉及变异策略,有效地避免了传统遗传算法易产生"早熟"的现象。并以永磁同步电机为例进行仿真验证。结果表明,优化后的自抗扰控制器具有良好的系统响应及控制精度,改进后的遗传优化算法适用于复杂非线性自抗扰控制器参数整定。     

加筋挡土墙长期工作性能的黏弹塑性有限元分析

随着工程上的广泛应用，作为设计中的关键技术问题之一，土工合成材料加筋挡土墙长期工作性能的合理评价日益得到重视，对此必须考虑加筋材料的非线性蠕变效应。对于加筋挡土墙，采用黏弹塑性流变模型和黏弹性本构模型分别考虑填土与土工合成材料的非线性蠕变性，合理考虑筋材与填土、填土与面板及面板之间的相互作用效应，同时在计算中反映逐层填筑过程，采用增量一初应变迭代法，对土工合成材料加筋挡土墙结构的工作性能评价发展了二维有限元数值分析方法。基于Denver黏性土试验挡土墙的试验结果确定计算参数，利用所建议的分析方法对Denver黏性土试验挡土墙进行了数值计算与分析，通过与实测结果及与常规方法的对比分析，论证了所建议的有限元数值分析方法的合理性及其可靠性。