基于空间啮合的内齿轮剃齿干涉分析

用空间啮合理论建立了内齿轮剃齿时展成干涉校核的数学模型,并给出了展成干涉与内齿轮和剃齿刀的齿数差、轴交角以及内齿轮的变位系数间的关系。该模型不仅可用于内齿轮剃齿时的展成干涉校核,也为交错轴螺旋齿轮内啮合传动的干涉校核提供了方法。     

PLC常见问题浅析及对策——PLC安全运行分析

PLC是专门为工业生产环境而设计的电气控制装置,一般不需要采取什么特殊措施便可直接在工业环境中使用.但是,若生产环境过于恶劣,电磁干扰特别强烈,或安装使用不当,将会影响PLC的正常安全运行.PLC的安装与接线应按照其使用手册要求进行,除了要满足一定的安装环境外,关于PLC的电源、PLC的接地以及输入和输出端接线等常见运行中出现的问题,根据经验可采用以下相应的对策.     

红外一氧化碳检测中干扰因素分析及补偿方法研究

不同气体对红外光有着不同的吸收光谱。某种气体的特征光谱吸收强度与该气体的浓度相关,利用这一原理可以测量气体浓度。利用红外光谱吸收原理检测一氧化碳（CO）是一种先进的检测手段,目前国内外用于精确测量和标定气体浓度的传感器基本上都是采用红外技术。这种传感器可采用敞开式气室结构,不进行气体预处理,直接进行在线测量,容易实现自动连续监测。然而在传感器的实际研制中,必须考虑如下这些干扰因素的影响,     

Process control of open and close of launcher’s hatch based on delay compensation and three variable controller

Our ship missile launch device switch cover part has been adopted hydraulic system with an action in the form of open loop control one way, causing motion accuracy cannot be guaranteed, become an important reason for restricting the development of the system. In order to improve the control precision of the switch cover process,based on electro hydraulic position servo system as the control object, using delay compensation solve the problem of hydraulic impact in the process of reversing valve commutation, using three variable controller to improve the movement accuracy. The controller of the design is experimentally tested, and two hydraulic cylinders are used to simulate the action of the switch cover and the interference force caused by the gravity of the well cover respectively, so as to control the interference and improve the precision of the motion. Experiments show that the control strategy can improve the precision of the switch cover.     

Functional response of adult Cheyletus malaccensis (Acari: Cheyletidae) to different developmental stages of Aleuroglyphus ovatus (Acari: Acaridae)

Cheyletus malaccensis is an important natural enemy of stored pests. In the study, the functional response of C. malaccensis against Aleuroglyphus ovatus was investigated under five constant temperatures of 16, 20, 24, 28 and 32 °C. The results showed that the functional response of adult C. malaccensis to different stages of A. ovatus was conformed to Holling II. Under the temperature between 16 and 32 °C, C. malaccensis females consumed more larvae and nymphs, followed by male and females of A. ovatus. While male C. malaccensis merely consumed larvae and nymphs of prey. Adult C. malaccensis ate few eggs of A. ovatus. The daily consumption and instantaneous attack rate (a/Th) increased with the temperature increasing from 16 °C to 32 °C while the peak was at 28 °C. The maximum daily consumption for larva and a/Th of female C. malaccensis are 135.1 and 110.7, respectively. Cheyletus malaccensis showed positive preference to larvae and nymphs, while negative preference to adults and eggs of A. ovatus. Because of the competition and interference among predators, the predation efficiency decreased with the density of predator increasing, and the interference coefficient (m) was 0.485 at 28 °C. These results could be helpful to provide theoretical basis and practical instructions for the biological control of A. ovatus by C. malaccensis.     

弧面分度凸轮机构参数化设计与仿真

以弧面分度凸轮机构为研究对象,基于VC 面向对象的方法及Pro/E二次开发技术,建立弧面分度凸轮参数化设计系统,该系统给出了界面友好的参数输入对话框,能够完成机构参数的自动综合和凸轮轮廓的自动生成,具有直观性,易于操作和调整,并在Pro/E环境下进行装配、仿真与干涉检测,验证了设计的合理性,为该机构的广泛应用提供了新方法和手段.     

摊铺机行走监控系统研制

为提高路面摊铺平整度、初始密实度,研制了一种基于CAN总线的摊铺机行走监控系统.该系统以C8051F040芯片为主控制器,采用模糊PID控制策略和CAN总线通讯技术,实现了摊铺机的实时监控和恒速控制.系统硬件和软件分别采用电磁兼容保护和抗干扰措施,通过了严酷的工业环境级别的电快速脉冲群试验.现场应用表明,该行走监控系统操作简单,具有智能化和可靠性等优点.     

基于UG的二次开发在装配干涉检测中的应用

分析了UG的干涉检验模块,针对效率低的问题,提出了在UG NX的平台下,通过.NET的C#语言编辑应用程序,结合使用UG/Open MenuSeript和UG/Open UIStyler二次开发工具,实现了提高UG的装配模块中干涉检测效率的方法,方便用户选择干涉组件,查看干涉结果,提高了使用UG的效率,缩短了产品设计周期。     

Removal of toxic metal Cr(VI) from aqueous solutions using sawdust as adsorbent: Equilibrium, kinetics and regeneration studies

In the present study, a low-cost adsorbent is developed from the naturally and abundantly available sawdust which is biodegradable. The removal capacity of Cr(VI) from aqueous solutions and from the synthetically prepared industrial effluent of electroplating and tannery industries is obtained. The batch experiments are carried out to investigate the effect of the significant process parameters such as initial pH, change in pH during adsorption, contact time, adsorbent amount, and the initial Cr(VI) concentration. The maximum adsorption of Cr(VI) on sawdust is obtained at an initial pH value of 1. The value of pH increases with increase in contact time and initial Cr(VI) concentration. The equilibrium data for the adsorption of Cr(VI) on sawdust is tested with various adsorption isotherm models such as Langmuir, Freundlich, Redlich–Peterson, Koble–Corrigan, Tempkin, Dubinin–Radushkevich and Generalized equation. The Langmuir isotherm model is found to be the most suitable one for the Cr(VI) adsorption using sawdust and the maximum adsorption capacity obtained is 41.5 mg g⁻¹ at a pH value of 1. The adsorption process follows the second-order kinetics and the corresponding rate constants are obtained. Desorption of Cr(VI) from sawdust using acid and base treatment exhibited a higher desorption efficiency by more than 95%. A feasible solution is proposed, for the disposal of the contaminant (acid and base solutions) containing high concentration of Cr(VI) obtained during the desorption process. The interference of other ions which are generally present in the electroplating and tannery industrial effluent streams on the Cr(VI) removal is investigated.     

避免圆柱齿轮干涉及根切的最小齿数研究

研究了圆柱齿轮的干涉根切现象,通过渐开线齿轮的根切现象详细分析了影响齿轮干涉的各种因素及作用原理.研究了国内外几种小齿数齿轮的设计理论.在此基础上研究了一种全新的小齿数齿轮设计方法,即反包络法.