共查询到20条相似文献,搜索用时 78 毫秒
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在物理气相沉积过程中,触发真空间隙是整个试验过程中最基本的一步,很多因素影响真空间隙的成功触发,本文对此加以讨论,并提供一下合适的触发电路。 相似文献
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岳宇鑫 《仪器仪表与分析监测》2023,(1):27-31
真空断路器的健康状态主要由其灭弧室触头决定,触头的烧损来自分闸过程中的电弧烧蚀。本文分析分闸过程中电弧和间隙等离子体对触头的影响过程,总结触头健康状况的影响因素和特征量,给出通过特征量检测灭弧室烧损状态技术手段,为运维人员有效预测和评价真空断路器健康状况提供参考。 相似文献
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针对电涡流传感器在进行叶尖监测时因带宽不足导致的欠采样问题,提出了一种基于触发脉冲的叶片健康监测方法。通过对传感器在不同叶尖相对位置的灵敏度进行标定,获得传感器灵敏度与传感器探头到叶尖的距离及与叶尖重合度的函数表达式。在监测过程中,将叶尖间隙与叶尖计时数据相融合,通过叶尖计时的方法得到在各个数据点的采集时刻,计算传感器探头与叶片的重合度,结合标定得到的函数表达式,可分析得出各个数据点对应的叶尖间隙值,并通过搭建的叶尖间隙监测实验台进行了实验验证。结果表明,较于峰值定位法,所提出的触发脉冲法有效地解决了因电涡流传感器带宽限制引起的欠采样问题,改善了高线速度下叶尖间隙的测量准确性,为基于电涡流传感器的叶尖间隙主动控制及叶片振动监测提供基础。 相似文献
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设计了一套硅片专用真空夹紧装置,包括夹紧装置和微型无油真空抽气泵。为减少硅片在夹紧过程中变形,夹紧装置采用了多吸口、回旋槽的平面型结构;根据所需夹紧力大小,设计了抽速为0.3L/s的微型真空泵,泵内无油避免了对硅片的污染;对间隙返流进行了计算并分析了对泵性能的影响。 相似文献
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真空钎焊工艺是在真空加热条件下,利用钎料熔点比基体合金低,熔化后的钎料在被焊工件小间隙的毛细管吸力作用下,填充基体金属间隙而使被焊材料形成牢固结合。由于真空钎焊加热温度较低,对基体金属的物理、化学性能影响不大,并可将复杂零件的若干条焊缝一次焊成,因而受到航空、航天及电子等行业的重视。 相似文献
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A standard commercially available cryopump system has been installed on a scanning electron microscope (SEM) using specially optimized vacuum vibration isolation bellows. This installation was successful in reducing the cryopump-induced vibration to a level that did not degrade the standard performance or resolution of the SEM in the pump-on mode and, in the pump-off (or coasting) mode, eliminated all measurable instrument-induced vibration (i.e., from the vacuum system). This article outlines the manner in which this performance has been accomplished and presents the results of an experiment demonstrating the reduction of specimen contamination provided by this type of vacuum system. 相似文献
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六氟化铀专用质谱计的改造 总被引:1,自引:1,他引:0
陈友宁!兰州信箱分箱兰州 《质谱学报》1999,(2)
中央分析室自制的六氟化铀专用质谱计在测量低丰度(铀-235 丰度小于1% )样品时,准确度较差(相对偏差±1% )。造成误差的主要因素是本仪器存在着明显的二次电子和强峰拖尾。本文从质谱理论和实际测量两方面分析了这两种因素的起因及其解决途径,通过对专用质谱计接收器和高真空系统的改造,消除了以上造成误差的两种主要因素。通过指标测试,证明专用质谱计的改造达到了预期结果(相对偏差小于±0.5% ),改造是成功的 相似文献
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D Gandolfi M Niedermayr M Kumph M Brownnutt R Blatt 《The Review of scientific instruments》2012,83(8):084705
We report on the investigation and implementation of a lumped-component, radio-frequency resonator used in a cryogenic vacuum environment to drive an ion trap. The resonator was required to achieve the voltages necessary to trap (~100?V), while dissipating very little power. Ultimately, for an input voltage of 1.35 V, a voltage gain of 100 was measured at 5.7 K, using a design which dissipated only 18 mW. The resonator operated at a frequency of 7.64 MHz and had a Q of 700. Single (40)Ca(+) ions were confined in a trap driven by this device, providing proof of successful resonator operation at low temperature. 相似文献
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Tinnion E Jowitt F Clarke-O'Neill S Cottenden AM Fader M Sutherland I 《Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine》2003,217(4):291-296
Continence difficulties affect the lives of a substantial minority of the population. Women are far more likely than men to be affected by urinary incontinence but the range of management options for them is limited. There has been considerable interest in developing an external urine collection system for women but without success to date. This paper describes the development and preliminary clinical testing of an active urine collection device (AUCD), which could provide a solution for sufferers. The device uses stored vacuum, protected by a high bubble point filter, to remove urine as quickly as it is produced. This allows a small battery-operated pump to provide the required vacuum, enabling the device to be portable. Two different types of non-invasive patient/device interface were developed, and tested by volunteers: urinal and small pad. The slimline urinal was popular with users although liquid noise was a problem. The pad interface was successful on occasions but further work is necessary to produce a reliable pad. This study has successfully demonstrated that a prototype AUCD liquid handling system can remove urine at clinically relevant flowrates. While further development is required, volunteer tests have shown that the AUCD could be a useful advance in continence management. 相似文献
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D. F. Alferov V. A. Nevrovskii V. A. Sidorov 《Instruments and Experimental Techniques》2004,47(1):63-68
The dielectric strength of triggered vacuum switches (TVSs) was studied using two measuring techniques. In the first of these, the voltage of the first TVS breakdown was measured at every slow increase in the voltage of the commercial frequency. In the second, a constant preset voltage was applied to a TVS several times until the gap was broken down. In this case, the number of successful experiments before TVS breakdown was recorded. It is shown that the results from processing the data obtained by different methods of measurement are in satisfactory agreement. The practical importance of the second measuring technique for determining the region corresponding to low breakdown probabilities in the TVS-breakdown probability distribution curve is demonstrated. 相似文献
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目前各总装分厂分体空调器室外机抽真空工序完成后,真空度是否达到灌注工艺要求,需对接到灌注机上灌注时才能检测到,存在灌注真空不良和二次强行灌注等隐患,影响产品质量的稳定性.同时,由于灌注机检测真空度的真空计与真空规管每年计量一次,真空计与真空规管在此期间损坏,外机的真空度是否达到要求难以保证.因此通过自主开发抽真空自动检测报警装置,彻底解决灌注机真空度无法得到有效可靠保证及有效可靠监管这一难题.实现有效监管、目视化管理,建立空调室外机真空度的防火墙,保证灌注前系统真空度达到工艺要求,杜绝强灌,消除质量隐患保证产品质量,同时也减少了返工概率,缩短生产抽真空的时间,提高生产效率. 相似文献
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真空度是影响滤油机真空分离系统工作效率的关键技术指标,以往的真空滤油机普遍存在极限真空度不足的现象。涡旋真空泵结构简单,运行稳定,且能在较宽的压力范围内工作,将涡旋真空泵作为前级泵应用到滤油机真空机组中,能为真空机组的主泵创造必要的预备真空条件,从而改善滤油机的整机性能。涡旋真空泵极限真空度受其抽气速度的影响,与泵体自身结构参数密切相关。选取合理的泵体结构参数,设计相应抽气速度的真空泵至关重要。基于涡旋真空泵的工作原理,建立理论抽速模型,通过计算封闭月牙形工作腔的容积,推导出理论抽速计算公式,对于选取泵体最优结构参数具有重要的理论指导意义和工程实用价值。 相似文献
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陈士杰 《机械制造与自动化》2011,40(6)
不同车辆制动踏板的软硬程度是不同的,造成差异的主要原因在于踏板是否具备助力机构.一般情况下,轿车采用的是真空助力器的结构.在不同大气压力下,车辆真空助力器内的真空度水平会有所变化,直接导致在高海拔地区整车制动系统的表现相比低海拔地区存在一定差异,甚至存在安全隐患.提出了轿车整车动态真空度的实验方法,对不同工况下的整车动态真空度进行试验,并对结果进行分析,为车辆制动系统的改进提供依据,同时避免了车辆上市后的潜在风险. 相似文献