一种用于气胸治疗的单向气阀装置

研发了一种用于气胸治疗的单向气阀装置。该单向气阀主要由阀体和阀瓣组成,连接在阀瓣上的弹簧由于弹性变形使得阀瓣与阀体密封,只有当导气管中的压强大于导通压强时,单向阀正向导通,反之截止。弹簧的压力可以调节,用于形成不同的导通压强,数字气压表的采用能够实时观察胸腔内的压强,为进一步治疗提供可靠依据。实验表明此单向阀小巧轻便、安全可靠,能最大程度地减轻患者的痛苦。     

一种新型的阀瓣结构

在航天器中，常常使用推力器作为姿控、轨控执行元件，推力器中的电磁阀动密封副常使用和推进剂相容的橡胶材料。本文介绍一种不用过渡层硫化成型的阀瓣结构，并指出了这种结构较目前流行的阀瓣结构有那些优越性。     

660MW超临界燃煤机组低压旁路阀频繁内漏处理方法探索研究

本文以某公司2×660MW超临界燃煤机组低压旁路阀频繁内漏（德国西门子原装进口产品）为例,经多次解体发现阀座与阀芯的密封面损坏,主要原因是由于杂质、异物等金属硬物卡涩所致,而系统复杂致锅炉侧死角异物难于彻底吹扫干净,一直严重影响机组安全经济运行。通过对低压旁路阀入口加装滤网、阀门研磨处理、减压孔扩孔、更换阀门、旁路阀阀芯改造等几种方案综合对比优缺点,最后确定对阀芯改造并进行可行性分析,实施效果明显,有效防止了阀芯与阀座密封面损伤,彻底解决了低压旁路阀频繁内漏问题,确保了机组运行安全经济性,无疑对具有类似问题的火电机组解决方案有一定的参考意义。     

电动耐腐蚀截止阀的选型设计与试验研究

为了选择某系列精细化学品生产装置进口电动耐腐蚀截止阀的国产替代品,分析了电动截止阀的操作特性,计算并确定了阀门操作转矩、电动装置输出转矩。选用国产DZY5型阀门电动装置,分析了其行程限制机构和转矩限制机构的工作情况,测试了其机电性能,并与进口电动阀作了性能比较。性能比较结果表明,两者的机电性能接近。将DZY5型阀门电动装置与J41W-25R截止阀配合构成电动截止阀,进行了气密性和流通性试验。试验结果表明,密封性和流通性均满足要求。选用C4不锈钢和115^#不锈钢进行阀门材质耐工艺介质腐蚀性试验,验证了115^#不锈钢具有更好的耐腐蚀性。经过选型和试验研究,提出了采用DZY5型阀门电动装置配用115^#不锈钢截止阀的电动耐腐蚀截止阀国产化技术方案。该方案为生产装置遥控阀门的重新选型设计提供了技术依据,对研制新型小口径电动耐腐蚀截止阀具有技术参考价值。     

用压力油填装液压存贮器的装置

此项发明特别适用于机动工作机上的液压回路中。 在使用管道3中,压力油由压力流量发生器通过单向阀2输送。在工作管道3中,接有下限值的限压阀4和上限值的限压阀5。在压力流量发生器1输送开始时,首先充满液压存贮器6,这时限压阀4和5还没有供给信号,截止阀7保持关闭。当限压阀4的压力达到预先调好的压力时,在阀的出口出现一定体积液流,此液流到达截止阀9和节流阀10。     

电液伺服阀的清洁、装配与调校

一、前言在光盘复制行业,老一代的注塑机大多采用的是液压驱动系统,随着设备的老化,各类油封的磨损、炭化,使油质严重污染,进而使得各种控制元件性能受到影响。作为核心部件之一的电液伺服阀,对液压系统洁净度要求极高,当伺服阀出现故障时往往难以     

一起先导式安全阀未起跳事故分析

2004年9月3日,新疆油田某作业区的处理站,因设置的AF46Y型先导式安全阀在出现系统憋压时,导阀起跳后主阀没有起跳或开度不够,导致大量天然气通过导阀放空管在装置区内泄放.事故发生后,作业区组织有关单位进行了原因查找和分析,并提出了合理化建议.……     

BS5系列微型光电传感器

奥托尼克斯BS5系列新增了Y型（BS5．Y2M）和V型（BS5．V2M）微型光电传感器,该系列多种不同的外型（K,T,L,Y,V型）,适用于多种安装方式,其连接头接插方式使用户使用更加方便。另外,其宽范围电源电压使得BS5系列易于连接不同的IC、继电器、可编程控制器、反射端／接收端窗口的防尘保护设计,使其信赖性更高,适用于更多环境。     

安全阀阀瓣膜传感器标定的理论与实验研究

通过对安全阀阀瓣膜传感器进行ANSYS数值模拟和相关实验研究,从理论和实验两方面探索了对阀瓣膜传感器进行标定问题,经过实验验证后,提出了一种准确可行的标定方案.首先,采用ANSYS软件模拟了阀瓣膜传感器承受不同载荷下的应变与压力的关系;同时也设计了一套阀瓣膜传感器的标定实验装置,利用该实验装置对阀瓣膜传感器进行了标定实验.标定实验结果分析表明,阀瓣在承受不同载荷的情况下,应变与压力呈良好的线性关系,线性度达到99.9%,并与相同载荷情况下ANSYS分析结果完全吻合,从而验证了这一标定实验方案的可靠性;通过对阀瓣膜传感器的灵敏度、线性度、重复性、滞后性等指标进行分析,结果显示其参数满足一般传感器的标准,验证了该传感器的可行性.     

组合式多路阀

5000型组合式多路阀是为液压系统设计的分片式阀体的多路阀。一个完整的5000型多路阀是由一批用来组成所需回路的阀片元件和阀的任选元件所组成。其任选机能包括，高压越过阀片传递、封闭换向阀片、中间一输入的集流或分流、并联和串并联及串联回路等。     

转盘偏置对转子系统动力学特性的影响研究

以Jeffcott转子系统为对象,研究转盘在转轴上不同偏置安装位置所引起的陀螺效应,以及对转子系统固有特性和弯曲振动模式的影响规律.基于所建立的集中质量模型,数值计算和比较的结果表明,不同的转盘安装偏置量会对转子系统临界转速和不平衡响应产生明显影响.偏置程度越大,陀螺效应对临界转速及不平衡响应的影响越大,而在转子系统完全对称的情况下,陀螺效应则可以忽略.     

用临界功率表征多相搅拌槽中搅拌效果

多相搅拌过程中常常根据临界搅拌转速表征搅拌效果。由于各种搅拌桨的功率准数不同,低临界转速的搅拌桨对应的搅拌功耗可能大于高临界转速的搅拌桨,因此,本文提出用临界功率作为表征手段。选取表面曝气和固体悬浮2个典型的多相搅拌过程进行了验证,结果表明:(1)在表面曝气过程中,达到临界曝气时六斜叶下推圆盘涡轮(PBRTD)桨的搅拌功耗比标准Rushton(RT)桨低,相同功耗下PBRTD桨的kLa也更高,与临界曝气转速的判定结果不同,临界功率法认为PBRTD桨更适合作表面曝气桨,这与表面曝气机理的认识相符;(2)下推折叶透平(PBTD)桨和三叶后掠(TBHA)桨的固体颗粒悬浮实验结果也表明TBHA桨的临界离底悬浮转速高但功耗更低,TBHA桨的整体循环能力更强,有利于固体悬浮。     

Thermo-elastic stress of a metal-matrix composite disc under linearly-increasing temperature loading by analytical and FEM analysis

In this study, the elastic stress analysis of a composite disc with aluminium matrix subjected to a linearly-increasing temperature distribution has been carried out. The values of tangential and radial stress components that have occurred under the effect of the temperature from the inner surface of the disc towards the outer surface have been obtained by two different methods, numerical and analytical. In the analytical analysis, a computer program has been developed to get the values of thermal stresses. But in the numerical study carried out with the finite-element method, Abaqus 6.8 package program has been used. As a result of these analyses, it has been observed that the stress values obtained from both methods support each other. It has been determined under this temperature distribution that tangential stress components are always on the condition of compression in the inner surface of the disc and of tensile in the outer surface. It has also been found out that radial stress components are always in the state of tensile along the whole profile of the disc. Finally, the stress analysis of the same composite disc subjected to this temperature distribution, but with a reduced mass, has also been examined numerically.     

Improving playability of Blu-ray disc drives by using adaptive suppression of repetitive disturbances

This paper deals with the problem of adaptive suppression of disturbances on Blu-ray disc drives servo-mechanisms. The proposed methodology is intended for enhancing playability of low quality media at higher rotational speeds. One of the main problems in controlling an optical disc drive concerns the control of the radial lens position which assures the disc playback. However, due to the rotary nature of the Blu-ray disc the most important sources of disturbances concern those that present periodic behaviour. The frequency of such disturbances is proportional to the disc speed and inversely depends on the radial lens position, making more difficult the task of the tracking-controller when a high speed playback is required. Here, a new parametric adaptation algorithm is proposed to reject the main narrow-band disturbances without increasing the controller bandwidth. The proposed scheme makes use of the internal model principle and the Youla–Kucera parameterization. The parametric adaptation algorithm together with the robust stability and performance analysis are part of the main contribution of this paper. An experimental-data study illustrates the behaviour of the high speed tracking control.     

相变光盘信息符的快速精确测量

导电式原子力显微镜(Conducting Atomic Force Microscopy:CAFM)和扫描表面电位显微镜(Scanning Surface Potential Microscopy:SSPM)已经被用于相变光盘的信息符成像。在实验中测量了带初始过程的商用DVD-RW光盘。通过比较,CAFM的测量结果明显好于SSPM的测量结果。DVD-RW在3.5m/s的线速度下的恰当刻写功率范围被CAFM确定为10-15mW。这是验证高密度记录符的一个很有效的方法。这种新方法也可以用于新型相变记录材料的研发中。     

The calculation of the distribution of the Sun glitter radiance on the ocean surface by observing from a geostationary orbit

This paper presents a method for calculating the distribution of Sun glitter radiances from the ocean surface and a definition of the contour of the Sun disc image on the smooth ocean surface. Remotely sensed data were recorded from geostationary orbit and the spherical form of the Earth and shadowing effect on the rough ocean surface were taken into account. The reflected Sun radiance was calculated using the stochastically distributed facets method. The results of the calculations showed that the size of the Sun glint-affected region of ocean and also the value of the Sun glitter radiance in this region depend on both the geometry of observation and the degree of ocean surface roughness (i.e. over ocean wind speed v     

Effective optic disc detection method based on swarm intelligence techniques and novel pre-processing steps

Diabetic retinopathy affects the vision of a significant fraction of the population worldwide. Retinal fundus images are used to detect the condition before vision loss develops to enable medical interventions. Optic disc detection is an essential step for the automatic detection of the disease. Several techniques have been introduced in the literature to detect the optic disc with different performance characteristics such as speed, accuracy and consistency. For optic disc detection, a nature-inspired algorithm called swarm intelligence has been shown to have clear superiority in terms of speed and accuracy compared to traditional detection algorithms. We therefore further investigated and compared several swarm intelligence techniques. Our study focused on five popular swarm intelligence algorithms: artificial bee colony, particle swarm optimization, bat algorithm, cuckoo search and firefly algorithm. This work also featured a novel pre-processing scheme that enhances the detection accuracy of the swarm techniques by making the optic disc region the highest grayscale value in the image. The pre-processing involves multiple stages of background subtraction, median filtering and mean filtering and is named Background Subtraction-based Optic Disc Detection (BSODD). The best result was obtained by combining our pre-processing technique, firefly algorithm and the parameters used for the algorithm. The obtained accuracy was superior to the other tested algorithms and published results in the literature. The accuracy of the firefly algorithm was 100%, 100%, 98.82% and 95% when using the DRIVE, DiaRetDB1, DMED and STARE databases, respectively.     

Intelligent control of braking process

Intelligent modeling, prediction and control of the braking process are not an easy task if using classical modeling techniques, regarding its complexity. In this paper, the new approach has been proposed for easy and effective monitoring, modeling, prediction, and control of the braking process i.e. the brake performance during a braking cycle. The context based control of the disc brake actuation pressure was used for improving the dynamic control of braking process versus influence of the previous and current values of the disc brake actuation pressure, the vehicle speed, and the brake interface temperature. For these purposes, two different dynamic neural models have been developed and integrated into the microcontroller. Microcontrollers are resource intensive and cost effective platforms that offer possibilities to associate with commonly used artificial intelligence techniques. The neural models, based on recurrent dynamic neural networks, are implemented in 8-bit CMOS microcontroller for control of the disc brake actuation pressure during a braking cycle. The first neural model was used for modeling and prediction of the braking process output (braking torque). Based on such acquired knowledge about the real brake operation, the inverse neural model has been developed which was able to predict the brake actuation pressure needed for achieving previously selected (desired) braking torque value in accordance with the previous and current influence of the pressure, speed, and the brake interface temperature. Both neural models have had inherent abilities for on-line learning and prediction during each braking cycle and an intelligent adaptation to the change of influences of pressure, speed, and temperature on the braking process.     

带微型涡轮的旋转盘腔内流场的数值仿真研究

对带有反预旋喷嘴的旋转涡轮盘腔内部流动特性进行数值仿真研究.采用Gambit2.10软件创建计算模型,采用Fluent6.1软件计算求解3个转速下(50rpm、800rpm、1300rpm)旋转盘腔内部流场的分布规律.压力速度耦合方法采用SIMPLE算法,各参数的离散采用二阶迎风格式.数值仿真结果表明:在低转速(50rpm)下,主要由进气惯性力控制流场内部结构;在过渡转速(800rpm)下,进气惯性力和旋转效应共同控制流场内部结构;在高转速(1300rpm)下,主要由旋转效应控制流场内部结构.同时得到流场内部切向速度的分布规律.     

磁盘伺服图形光刻机主轴稳速系统设计

该文叙述了影响磁盘伺服图形光刻机主轴转速误差的主要来源,分析了主轴稳速系统是实现光刻机均匀刻录不可缺少的重要环节,提出了提高主轴稳速精度具体设计方案。