鞭炮引线插装自动机械设计

介绍机电一体化设备-鞭炮引线插装自动机械，讲述其工艺流程，主要结构，气动系统及PLC控制。     

A New Metric for Grey-Scale Image Comparison

Error measures can be used to numerically assess the differences between two images. Much work has been done on binary error measures, but little on objective metrics for grey-scale images. In our discussion here we introduce a new grey-scale measure, <img src="/content/l7443g0545335422/xxlarge916.gif" alt="Delta" align="BASELINE" BORDER="0"><sup>g</sup>, aiming to improve upon the most common grey-scale error measure, the root-mean-square error. Our new measure is an extension of the authors' recently developed binary error measure, <img src="/content/l7443g0545335422/xxlarge916.gif" alt="Delta" align="BASELINE" BORDER="0"><sup>b</sup>, not only in structure, but also having both a theoretical and intuitive basis. We consider the similarities between <img src="/content/l7443g0545335422/xxlarge916.gif" alt="Delta" align="BASELINE" BORDER="0"><sup>b</sup> and <img src="/content/l7443g0545335422/xxlarge916.gif" alt="Delta" align="BASELINE" BORDER="0"><sup>g</sup> when tested in practice on binary images, and present results comparing <img src="/content/l7443g0545335422/xxlarge916.gif" alt="Delta" align="BASELINE" BORDER="0"><sup>g</sup> to the root-mean-squared error and the Sobolev norm for various binary and grey-scale images. There are no previous examples where the last of these measures, the Sobolev norm, has been implemented for this purpose.     

基于l_(2,p)-范数的ECT图像重建算法

针对电容层析成像系统图像重建过程中Tiknonov正则化解过度光滑引起的重建图像细节信息丢失问题,引入l_(2,p)(0p≤1)的混合范数作为正则化算法的数据项和正则化项。混合范数l_(2,p)利用了欧氏范数l_2的光滑性和分数范数l_p(0p≤1)的稀疏性,不仅比范数L_(2,1)具有更好的联合稀疏性,对噪声的抗干扰性也更强,进而针对l_(2,p)矩阵范数的非凸、非Lipschitz连续问题提出一种新的电容层析成像图像重建模型。实验结果表明,基于矩阵混合范数l_(2,p)极小化优化模型的正则化算法相比牛顿迭代、奇异值分解、共轭梯度算法具有更强的适应性,更高的图像分辨率及更好的成像质量。     

Characterization and stability analysis of oil‐based copper oxide nanofluids for medium temperature solar collectors

Thermal oils are widely used as heat transfer fluids in medium temperature applications. Addition of small amounts of nanoparticles in such fluids can significantly improve their thermophysical properties. This paper presents experimental investigation of an oil‐based nanofluids prepared by dispersing different concentrations (0.25 wt%–1.0 wt%) of copper oxide nanoparticles in Therminol‐55 oil using two‐step method. Shear mixing and ultrasonication were used for uniform distribution and de‐agglomeration of nanoparticles to enhance the stability of the suspensions. The effect of nanoparticles concentrations on thermophysical properties of the nanofluids was analysed by measuring thermal conductivity, dynamic viscosity, effective density and specific heat capacity at different temperatures (25 °C–130 °C). Thermal conductivity exhibited increasing trend with rising temperature and increase in nanoparticles loading. A significant decrease in dynamic viscosity and effective density against increasing temperature makes it suitable for medium temperature applications. Nano‐oils with improved thermal properties are expected to increase the efficiency of concentrating solar thermal collectors.     

Stability and l2‐gain of discrete‐time switched systems with unstable modes

This paper addresses stability and <i>l</i><sub>2</sub>‐gain for discrete‐time switched systems with unstable modes based on slow/fast mode‐dependent average dwell time (MDADT) switching strategies. Firstly, by employing a class of multiple discontinuous Lyapunov functions (MDLFs) and developing a kind of alternative switching signals, the sufficient conditions on stability are established for the system without external disturbances under a slow/fast MDADT switching scheme with a tighter bounds on the dwell time. Furthermore, by defining indicator functions and exploring the features of slow/fast MDADT switching, the weighted <i>l</i><sub>2</sub>‐gain conditions are achieved for the system with external disturbances. Particularly, the criteria of stability and <i>l</i><sub>2</sub>‐gain are also established for the corresponding discrete‐time switched linear systems with unstable modes via the MDLFs method and the slow/fast MDADT switching strategy. Finally, two numerical examples are presented to illustrate the advantages of the proposed methods.     

Synthesis and purification of trisulphoindigo and reversed-phase high performance liquid chromatographic determination of trisulphoindigo in FD & C Blue No.2

The effect of temperature on product formation during the sulphonation of indigo with concentrated sulphuric acid and 30 % fuming sulphuric acid was studied with the aid of high performance liquid chromatographic (HPLC) analysis. Trisulphoindigo was prepared by the sulphonation of indigo with concentrated sulphuric acid at 160°C. The di- and tetra-sulphoindigo side products formed during the reaction were removed by preparative HPLC to yield a product of high chromatographic purity. The trisulphoindigo content of the food dye FD & C Blue No. 2 and the purity of commercially available trisulphoindigo were determined by HPLC analysis.     

甘油连续生物歧化过程的过渡行为及其数学模拟

用肺炎杆菌将甘油转化为１,３－丙二醇过程对稀释速率和底物进料浓度变化的过渡行为反映了细胞生长和胞内物质代谢在不同条件下存在着显著的差异。体系的过渡响应取决于操作条件变化前后系统所处的状态,当底物浓度由限制状态向剩余状态过渡时,甘油的残余浓度不断上升,而乙醇的浓度则逐渐下降,同时生物量、１,３－丙二醇和乙酸的浓度呈现先增后降的趋势。本文用“甘油浓度变化速率”的概念修正了菌体生长模型,并对甘油歧化过程     

Reinvestigation confirms action of Δ11-desaturases in spruce budworm moth sex pheromone biosynthesis

The biosynthesis of a large number of sex pheromone components of various moth species has been shown to start with common fatty acids and involve chain shortening by two carbons and introduction of a double bond at the 11–12 position. A recent report indicates that one of these common components, (<i>E</i>)-11-tetradecenyl acetate, is present in the eastern spruce budworm,<i>Choristoneurafumiferana</i>, but is not made by this pathway. Reinvestigation of this insect using in vivo and in vitro techniques indicates that the acetate indeed is made by a sequence of reactions similar to that used in other leafroller moths. In fact, evidence was found for the presence of several <img src="/content/lp470213u73u41l8/xxlarge916.gif" alt="Delta" align="BASELINE" BORDER="0">11-desaturase systems in spruce budworm. One produced a large quantity of (<i>Z</i>)-11-hexadecanoic acid, and another produced (<i>E</i>)-11-tetradecanoic acid. It is not known if the small amount of (<i>Z</i>)-11-tetradecanoic acid is produced by either of those two systems or by a third system. A comparison with other species showed that cabbage looper moths have only the first system, redbanded leafroller moths use the last two systems, and European corn borer moths have all three.     

Response of The Lacewing Chrysopa cognata to Pheromones of its Aphid Prey

The lacewing <i>Chrysopa cognata</i>, one of the principal predators of aphids in Korea, was tested for responses to the aphid sex pheromone components (4a<i>S</i>,7<i>S</i>,7a<i>R</i>)-nepetalactone and (1<i>R</i>,4a<i>S</i>,7<i>S</i>,7a<i>R</i>)-nepetalactol and the aphid alarm pheromone (<i>E</i>)-<img src="/content/m1l140k51275827u/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-farnesene. Electroantennogram responses were obtained to the sex pheromone components but not to (<i>E</i>)-<img src="/content/m1l140k51275827u/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-farnesene. The sex pheromone components were attractive in a Y-tube olfactometer assay and in field trials with water traps, but no attraction was observed to (<i>E</i>)-<img src="/content/m1l140k51275827u/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-farnesene.     

巡线机器人视觉导航中的摄像机现场标定

为在工作现场对巡线机器人视觉系统中的摄像机进 行标定,提出了一种自动化的标定方法。方法首先通过视觉检测地线和线上的运动目标,发 现目标后,控制机器人沿地线作低速运动。检测到目标进入处理区域时,记录目标上最前端 点的坐标,然后变换2次视角,获取3个视角下的一系列图像。在处理中, 提取每个视角下间隔Δn帧的n幅图像中目标上的最前端点,以通过该点的地线 的垂线与地线两侧边缘线及轴线的交点形成 2×(n－1)的棋盘格,并对格点进行校正。然后利用地线尺寸、机器人速度和被处理帧间的 时间差等已知条件,获取图像中的点 与其三维空间点间的对应关系,最后利用张氏标定法相同的处理方式,解算出摄像机的内外 参数。结果 通过实验验证,以张 氏标定结果为准,该算法对内参中的焦距误差不超过5%。通过本文算法,可实 现摄像机的工作中的自动标定,无需人工拍摄标定参照物,不需人工干预,能较好的实现自 动化。