嵌入式实时数据库系统的研究与设计

在分析研究嵌入式实时数据库系统的体系结构、关键技术、功能及特点的基础上,设计了测控系统中的嵌入式实时数据库系统并开发了相应的基于图形界面的管理系统。在开发系统的过程中,分析了传统嵌入式实时系统的各种解决方案的基础上,主要从模型建立、物理结构设计、查询优化等方面给出了较好的解决方案。     

A New Type I Peritrophic Membrane Protein from Larval Holotrichia oblita (Coleoptera: Melolonthidae) Binds to Chitin

Peritrophic membranes (PMs) are composed of chitin and protein. Chitin and protein play important roles in the structural formation and function of the PM. A new type I PM protein, HoCBP76, was identified from the Holotrichia oblita. HoCBP76 was shown as a 62.3 kDa protein by SDS-PAGE analysis and appeard to be associated with the PM throughout its entire length. In H. oblita larvae, the midgut is the only tissue where HoCBP76 could be detected during the feeding period of the larvae. The predicted amino acid sequence indicates that it contains seven tandem chitin binding domains belonging to the peritrophin-A family. HoCBP76 has chitin binding activity and is strongly associated with the PM. The HoCBP76 was not a mucin-like glycoprotein, and the consensus of conserved cysteines appeared to be CX_13–17CX₅CX₉CX₁₂CX₇C. Western blot analysis showed that the abundance of HoCBP76 in the anterior, middle and posterior regions of the midgut was similar, indicating that HoCBP76 was secreted by the whole midgut epithelium, and confirmed the H. oblita PM belonged to the Type I PM. Immunolocalization analysis showed that HoCBP76 was mainly localized in the PM. The HoCBP76 is the first PM protein found in the H. oblita; however, its biochemical and physiological functions require further investigation.     

工业废渣混凝土对称双排四孔多孔砖抗折强度的试验研究与数值模拟

基于相关的试验和非线性有限元计算等手段,对实用化程度较高的工业废渣混凝土对称双排四孔多孔砖抗折性能进行了试验研究和相关的数值模拟.得到了该试件在折压状态下的宏观变形形态,以及不同载荷加载情况下多孔砖裂缝的发生位置,并将其数值模拟结果与试验测试结果进行了比较、分析.为该类多孔砖孔型的设计与优化提供了有利的依据.     

Influence of Crack on Structure Vibration of Gear Tooth

This paper presents a theoretical model for analyzing the dynamic characteristic such as natural frequencies and vibration mode shapes of cracked gears. The influence of crack position and crack size on the dynamic characteristic of gears is thoroughly investigated using the proposed theoretical model as well as the finite element method (FEM) for the sake of model validation. The theoretical analysis and numerical simulation show that the influence of crack size and crack position on the dynamic responses of cracked gears is significant and that the influence of crack position is larger than that of crack size. The natural frequencies drop with the increase of crack size and the low order natural frequencies drop more notably. The natural frequencies drop more significantly when crack is located at tooth root than at tooth tip. The vibration mode shapes of cracked gear tooth are very different from those of gear tooth without crack, and the vibration amplitude increases significantly in crack neighborhood. These observations are very valuable for damage detection and fault diagnosis of gear system.     

时滞在磁流变主动控制系统中的影响

在分析磁流变阻尼器的时滞特征,时滞对单自由度磁流变控制系统影响基础上,将磁流变阻尼器应用于高速机车系统的振动控制中.从理论角度分析了基于磁流变阻尼器的四分之一机车系统在主动控制下的时滞问题,并进一步探讨了主动控制下时滞对高速机车系统整车悬挂系统的影响.仿真分析了高速机车系统整车模型应用磁流变阻尼器后,在主动控制下的时滞影响.结果表明,能够快速反映的磁流变阻尼器并不能彻底消除控制系统的时滞问题.磁流变主动控制系统在较大时滞的影响下,高速机车振动加剧,安全性受到威胁,甚至失去控制.     

基于改进鲸鱼优化算法的血液供应链网络多目标鲁棒优化设计

为解决血液供应链网络设计中的不确定性问题,建立了一种血液供应链网络多目标鲁棒优化设计模型。首先,针对带有5个节点的血液供应链网络,建立考虑安全库存的、目标为成本最小、存储时间最短的优化函数,并采用ε约束、Pareto最优和鲁棒优化方法对已建模型进行处理,将多目标问题转化为单目标鲁棒问题;其次,对原有鲸鱼优化算法（WOA）进行改进,引入差分算法的交叉和变异理念,增强了搜索能力并改善了局限性,从而得到差分鲸鱼优化算法（DWOA）,并采用此算法对处理后的模型求解。通过数值实例,验证当测试问题相同时,优化模型在需求短缺方面比确定模型的短缺量平均少76%。因此,所提优化模型在应对需求短缺时更具优势;通过仿真对比分析图像,得出DWOA相比WOA、粒子群优化（PSO）算法和遗传算法（GA）中断时间更短并且成本更低。     

基于高阶累积量的齿轮系统故障检测与诊断

详细讨论高阶累积量(Higher order cumulants,HOC)的特点和性质,分析基于HOC理论的相关信号处理技术,以及在处理随机信号的非线性特性时独特的功能.基于HOC的振动信号分析处理技术,即双谱分析、1.5维谱分析以及双相干谱分析方法,分析了各自特点以及估计算法.在此基础上,将HOC引入到机械传动齿轮系统的故障诊断分析之中, 对系统故障特征进行提取并对故障类型进行区分.对不同大小和不同类型故障的传动系统进行试验测试,采用HOC进行特征提取识别,并对HOC理论实际应用效果作了分析评价,表明HOC是一种较理想有前途的有效方法.     

基于非均匀消除-扩散概率分布的情绪化细菌觅食算法

针对传统的细菌觅食算法在优化过程中存在的趋化步长的不确定性及消除-扩散概率的恒定性不足的问题，提出一种基于非均匀消除-扩散概率的情绪化细菌觅食算法，以解决高维度工程优化问题。首先，在趋化步骤中利用古斯分布搜索机制对细菌个体位置进行更新，以解决细菌因以随机方式在每个维度上游动或翻转而导致的搜索能力差及易陷入局部最优的问题，引入情绪感知因子，利用情绪智能的突变来实现自适应趋化步长，从而避免算法过早收敛；其次，针对细菌个体在消除-扩散过程中概率的恒定性，提出利用线性和非线性概率分布代替传统的常数分布以此实现非均匀分布的构想，通过引入动力因子随机值，限制未定义的搜索空间中的细菌个体，从而节省算法的计算成本。通过六个基准测试函数进行测试，测试结果表明，在计算成本较低的情况下，除针对Rosenbrock函数外，所提算法针对所有函数均具有较低的迭代次数及良好的优化质量，且算法收敛性对比结果表明所提的算法具有较好的收敛性。     

A multi-channel photometric detector for multi-component analysis in flow injection analysis

The detector, a multi-channel photometric detector, described in this paper was developed using multi-wavelength LEDs (light emitting diode) and phototransistors for absorbance measurement controlled by an Intel 8031 8-bit single chip microcomputer. Up to four flow cells can be attached to the detector. The LEDs and phototransistors are both inexpensive, and reliable. The results given by the detector for simultaneous determination of trace amounts of cobalt and cadmium in zinc sulphate electrolyte are reported. Because of the newly developed detector, this approach employs much less hardware apparatus than by employing conventional photometric detectors.     

后防护横梁壁厚和吸能的关系研究及仿真

在发生货车被追尾碰撞时,为了达到保护后车和车上乘员的目的,必须在后防护装置的有限许可范围内,应尽可能提高碰撞发生瞬间后防护横梁和斜支撑构件的弹塑性变形所吸收的能量。本文利用LS-DYNA仿真软件对圆形横截面横梁壁厚分别为6mm、6.5mm和7mm时其缓冲吸能性进行对比分析。通过动态仿真不同壁厚的圆形横截面后防护横梁在碰撞过程中的变形、碰撞减速度以及吸能情况,表明当后防护横梁取圆形横截面时,壁厚值越小其缓冲性能最好,吸收内能最大。