一种自动卷线机构的设计

针对部分探测设备预留较长的线缆造成操作不便的问题,设计一种基于平面涡卷弹簧的自动卷线机构.阐述了自动卷线机构的原理,并对其进行理论分析和涡卷弹簧的设计计算.通过实际应用表明,自动卷线机构结构紧凑,占用空间小,重量轻,安装方便,卷线顺畅,较好地解决了某些探测设备线缆外露过长和走线凌乱的问题.对于其它有卷线需求的设备,它同样有着较高的参考价值.     

风廓线雷达探测资料分析

本文在叙述风廓线雷达测风原理、大气散射机理与风廓线雷达回波强度关系的基础上,对某型风廓线雷达探测数据与气球测风资料进行了对比,分析了两种不同测风体制生成的风探测资料的差异,同时对风廓线雷达探测资料在靶场不同天气过程下的特征进行了初步分析,为进一步发挥风廓线雷达在常规靶场的应用提供了一些参考。     

三角网格牙颌模型上的牙弓线半自动探测方法

介绍了一种在三维三角网格牙颌模型上半自动探测牙弓线的方法。首先使用三维激光测量系统对牙颌石膏模型进行测量获得数字模型;其次在网格模型上交互拾取4个参照点以确定咬合平面;接着使用顶点法矢和咬合平面作为参考,筛选出初始特征点并拟合出初始牙弓线;以初始牙弓线作为新的参考依据筛选出最终特征点,拟合最终参照点得到最终牙弓线。使用多副牙颌模型对该方法进行了测试,验证了该方法稳定、有效。     

点火器自动落线机的研制

现阶段压电点火器生产企业多采用人工作业的方式对铝条装点火器进行落线和清胶,针对人工作业方式劳动强度大、时间成本高、不满足现代化工业生产要求的问题,研制出一种对铝条装点火器自动落线和清胶的设备。运用概念设计的思想将自动落线机分解为上料输送机构、取料机构和落料机构等子功能机构,然后对各个子功能机构分别进行系统化的结构设计,最后将各个子功能机构集成设计得到了一种新型点火器自动落线机。通过对铣刀的结构改进和优化实验解决了自动落线机清胶的关键技术问题。从使用情况来看,自动落线机实现了铝条装点火器的上料、落线和清胶等环节的自动化,降低了劳动强度和生产成本,完成了研制要求。     

风廓线雷达有效探测高度评估方法研究

文章通过信号仿真的方法，得出风廓线雷达最高有效探测时回波信号的信噪比理论阈值，并利用福建省德化县风廓线雷达站和晋江市风廓线雷达站2020年的探测资料进行了验证，结果表明：实际信噪比与通过信号仿真实验得出的理论信噪比阈值具有较好的一致性，表明了理论信噪比阈值的准确性，以及通过信噪比阈值算法来评估的风廓线雷达实际有效最大探测高度的可行性，为风廓线雷达探测高度评估方法的研究提供了一种新的思路。     

风廓线仪在低空风切变探测中的应用

低空风切变是航空器起飞、着陆阶段威胁飞行安全的危险因素。文章根据首都机场风廓线探测资料,按照雷雨型、锋面型、逆温型、低空急流型和其他型,对产生的低空风切变过程进行了分类和统计;并利用风廓线探测资料,个例分析了几种产生低空风切变的风场特点。     

船载风廓线雷达试验与分析

船载风廓线雷达是一种新型海上测风仪器。本文通过一次冷空气过境过程的船载风廓线雷达探测试验,并对船载风廓线雷达探测结果与实况传真图进行比较分析,证明了该船载风廓线雷达能较好地反映冷空气前区的风向、风力变化,与实现传真图吻合较好。     

关于截面线数据特征线提取的研究

特征线的提取是逆向工程中的关键环节之一,截面线数据作为逆向工程中重要数据来源对其进行特征线提取研究有着重大意义。近年来,对于特征线提取的研究大都针对于点云和三角网格数据,对于准有序的截面线数据的研究较少。提出一种截面线数据特征线自动提取的算法,光顺截面线轮廓,去除噪点和误差较大的点;计算离散曲率,曲率突变的点即为特征点;提出特征线自动生成算法,自动识别分叉点,偏差点,将得到的特征点集拟合生成光滑特征线。     

基于CAN总线的故障电弧探测系统的研究

探讨了电弧的特性和它造成的危害,提出了故障电弧探测系统(FADS)的工作原理和结构。通过建立探测系统优化了传统故障电弧断路器结构,克服了其功能单一的缺陷。FADS由探测器、控制器和上位机组成,汇集了故障电弧探测、高温故障探测和剩余电流探测等功能。探测器、控制器和上位机通过CAN总线进行通讯,CAN总线的使用降低了通讯成本、提高了通讯质量。     

利用热释电红外传感器探测人体运动特征

热释电红外(PIR)传感器探测人体发出的红外辐射,在有效探测范围内可实现运动人体的检测.由于它的低成本低功耗,在入侵检测及自动照明控制等方面有广泛的应用.本文对用这种传感器提取人体行走时的运动特征进行了研究.人作为动态的分布式的红外源由体貌特征及步态特征所决定,利用探头表面安装有菲涅耳透镜的PIR传感器得到时域电压信号,对信号的频谱特性进行分析来解析人体的运动特征.采用主成分分析方法对不同个体不同速度的数据进行分类,探讨了这种方式应用于人体运动特征信息的提取及分类识别的可行性.实验结果表明,不同的人以不同的速度步行的频谱数据足以用来分类识别,为安全级别较低场所的人体身份识别提供了一种低成本的方案.     

TBS全自动离心机刮铲卸料装置的动态特性分析

通过对TBS全自动间隙离心机刮铲装置在生产过程出现的问题进行分析;采用用户自定义矩阵单元来处理刮铲装置结合部的接触问题,在Pro/E软件上建立了刮铲装置＂Z＂轴的有限元模型,并对其进行了动态特性分析。运用该方法来进行结构的性能预测,并用于工厂对该装置的结构进行改进设计。     

基于提升方法的整数小波在DSP上的实现

在理论上探讨了基于提升框架的整数小波变换(IWT)及其硬件实现问题,并在TI公司的TMS320C6000DSP上实现了图像处理中两种常用滤波器LEGall(5,3),Sweldens(13,7)提升结构的整数小波变换,同时在DSP上对上述滤波器实现了滤波器组(FBS)方法的离散小波变换(DWT).将提升方法的IWT同FBS方法的DWT在硬件上的运行时间作了比较.结果表明,IWT的运行速度比DWT的运行速度快.本结果可用于评价DSP在图像编码中的运行情况,也可估计出采用此种算法每秒能处理的图像数目.理论和实验均表明,基于提升方法的整数小波变换是一种运行速度快,易于硬件实现,并能实现图像无损压缩的算法.     

基于Ansys对提升机卷筒集中应力的分析

针对提升机卷筒在人孔周边及筋板处因应力集中而容易产生裂纹的情况,以降低卷筒上人孔的应力集中为目的,重点运用ANSYS软件对直径2．0mJK型提升机卷筒的人孔的不同形状进行有限元分析,对不同人孔形状做出对比,并对腰形孔的不同位置进行了分析。     

基于连续函数近似法的空气污染源管控

本文根据空气污染源强度对杂质浓度影响的一致性评价方法,在几个固定点监测空气质量。在对空气中杂质传播过程的描述当中运用 Duhamel 定理的数值模拟。这种方法以合理复杂性的数学模型为基础,使模拟结果的准确性得到增加。根据静止或移动控制点中杂质浓度的测量结果,使污染物在大气中传播的逆问题通过顺序函数的近似值得以解决,且该解决方案以数字滤波器的形式提出。     

Measurement of potential distribution function on object surface by using an electron microscope in the mirror operation mode

The quantitative theory of image contrast in an electron microscope in the mirror operation mode is given in this paper. This theory permits us to calculate the potential distribution on the object surface from the current density distribution on the microscope screen. The potential distribution results in image formation on the screen. Local electric fields existing on the object surface lead to a perturbation of electron trajectories above the object and to a redistribution of the current density on the screen, causing image contrast. Using the quantitative correlation between these fields and the function of current density distribution on the screen, it is possible to calculate the magnitude of these microfields as well. As illustration, a measured potential distribution on an object surface with spiral structures of adsorbates was analysed. These structures are formed during reaction of CO oxidation on Pt(110). The value of the measured contact potential difference comprised a few hundredths of volt.     

砂轮修整器的设计

本文主要阐述了砂轮修整器的设计结构原理,为了满足生产的需要,设计制作了砂轮修整器,安装在手摇磨床上进行修整砂轮,完成工件加工。砂轮修整器具有结构简单,轻巧,使用方便等特点,可对普通和超硬型砂轮进行整修。本砂轮修整器可安装在普通砂轮机、手摇磨床、平面磨床、内外圆磨床上,通过调节外径千分尺和转动各手柄,对砂轮凹凸圆弧,角度、轮廓面进行修整。     

Study on development of polyamide gears for improvement of load-carrying capacity

In polyamide based gears, thermal damage of the gear tooth surfaces occurs during gear meshing due to accumulated heat in the tooth body. In the experimental study reported in this paper, polyamide gear teeth have been modified in order to distribute the generated heat on the tooth surface by means of drilled cooling holes at different locations on the gear tooth body. The main aims of this paper were to study the effect of cooling holes on the accumulated heat on the tooth surface and on the measured wear. It was shown that the drilled cooling holes on the tooth body decreased the tooth surface temperature and led to an increase in the load carry capacity and improved wear resistance. Geometrically modified gears have showed an improved service life and a decreased surface temperature.     

Wear of single crystal silicon as a function of surface roughness

With increasing activities on micro electro-mechanical systems (MEMS) type microactuators, there is a growing need in understanding the tribological properties of silicon, the most commonly used wafer material for those devices. In particular, it is of interest if single crystal silicon used in microactuators exposed to rather low vertical loads is subject to wear. Therefore, wear tests using monocrystalline silicon on both sides of the tribological interface were conducted.A classic way to measure wear on sliders in contact with a tape or a rotating disk is to create an imprint using a Berkovich diamond tip mounted on a picoindenter. However, in our case we used a different approach. We created three studs on a slider’s surface by recessing the material outside the studs through an ion milling process. During the wear tests, the studs wore off. By measuring the remaining stud height, the wear volume could be determined at any point in time. The tests were performed on a pin on disk tester with a gimbaled slider to realize a flat on flat contact and a rather low normal force of 30 mN.     

Latex on Glass: an Appropriate Model for Cartilage-Lubrication Studies?

Latex versus glass has frequently been used as a model system for the investigation of natural lubrication mechanisms, despite its significant differences from articular cartilage pairings. The differences in surface chemistry account for its different behavior in terms of protein adsorption and lubrication. While cartilage is well known for its protein resistance, most proteins present in synovial fluid can non-specifically adsorb onto latex or glass. We have investigated latex-versus-glass lubrication by means of pin-on-disk tribometry in the presence of synovial-fluid proteins and glycoproteins, focusing on the influence of the glass-cleaning procedure on friction. In order to simulate the effects of possible contamination of glass in previous studies, both hydrophilic and hydrophobic glass substrates were tested. Albumin was shown to impair lubrication (in comparison to PBS) when latex was slid against both types of glass surface, whereas bovine synovial fluid (BSF) and alpha-1-acid glycoprotein (AGP) impaired the lubrication of latex versus hydrophilic glass and improved the lubrication of latex versus hydrophobic glass. Protein adsorption on the surfaces was monitored by means of fluorescence imaging and optical waveguide lightmode spectroscopy (OWLS), which revealed a faster and greater amount of adsorption of AGP on hydrophobic surfaces than on hydrophilic ones. The influence of surface chemistry on the friction behavior of BSF and on the adsorption of AGP suggests that it plays a role in determining the relative amounts of adsorbed synovial fluid proteins. When BSF is used as a lubricant in the latex-versus-hydrophobic-glass system, more of the AGP, relative to albumin, appears to adsorb on both surfaces, counteracting the negative effect of albumin on friction. It therefore seems that latex on glass, while displaying nominal similarities to cartilage on cartilage under certain conditions, is not a useful model system. Moreover, surface contamination of the glass can play a major role in determining the results.     

Operational transfer path analysis: Theory,guidelines and tire noise application

The operational transfer path analysis (OTPA) method is the subject of research in this article, which starts with a discussion on it's theory. Here clear similarities with the MIMO technique in experimental modal analysis are found. Based on the knowledge of MIMO, one finds that input signals are allowed to be coherent to a certain extend. As coherence can be larger in OTPA in practice, the method is extended with the singular value decomposition method to reduce influences of noise. The article proceeds with a discussion on points of attention, or boundary conditions, in practical applications. An analysis on tire noise is included to illustrate the points of attention and the methods strength in, for example, vehicle TPA on tires.