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关于飞机液压系统的几个问题 总被引:1,自引:0,他引:1
为了完成飞机的预定功能,机上配置各种不同的系统,诸如操纵系统,液压系统、燃油系统、动力系统、空调系统、防冰防雨系统、氧化系统、电源系统、导航系统等等。其中液压系统是属于关键系统之一。该系统的工作情况直接与飞行安全密切相关。一般来说,它要承担飞机起落架的收放、刹车,各操纵活动面(副翼、方向 相似文献
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张琳 《工业仪表与自动化装置》2017,(1)
介绍了HR-906B GPS时间同步系统在化工企业自动控制系统中的时钟同步应用,和HR-906B GPS时间同步系统的组成及系统自身的搭建过程。另外介绍了主时钟系统在DCS系统、SIS系统的配置过程。该文所例举的DCS系统为横河CENTUM-VP系统,SIS为RTP的3000系统的一般配置方法。 相似文献
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从CAPP系统的现状出发 ,分析了当前CAPP系统的问题 ,提出了面向PDM的集成化CAPP系统的思想。针对SmarTeam这一PDM软件给出了系统的体系结构 ,随后对CAPP系统和SmarTeam系统的集成技术进行了研究 ,探讨了CAPP系统与SmarTeam系统集成的关键技术 相似文献
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建立了机械式离心调速器系统的动力学方程,求出了系统的平衡点。利用系统的相图分析了给定参数下自治系统及非自治系统的运动状态,用Poincare映射图分析了非自治系统混沌的形成过程。利用线性反馈反控制方法实现了自治系统及非自治系统混沌的反控制,将自治系统及非自治系统的周期运动利用适当的控制强度反控制到混沌运动轨道。 相似文献
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李慧洁 《机电产品开发与创新》2018,(5)
介绍民航机场机坪塔台工艺典型设计方案,分析了甚高频系统、记录/重放系统、时钟系统、全景可视化运行监控系统、语音交换系统、引接机场系统以及引接空管系统等的设计要求。 相似文献
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由于植物一定程度上可以吸附空气中的氟和硫,所以,合理种植抗污染性能强的植物种类,十分重要。本文对南通市5个点位的绿色植物体内的氟化物和硫化物进行了测定。结果表明,它们对大气中的污染物有很强的吸收和富集作用,秋季叶片中硫和氟污染物的含量高于春季,且与污染强度相吻合。研完污染物在植物体内的积累是监测和评价大气污染的十分有效的方法。 相似文献
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在某燃气站场投产前的试压过程中,发现一处弯头外弧侧管体出现纵向裂纹,导致试压泄漏。通过力学性能检验、组织分析、扫描电镜分析及能谱分析,讨论了该弯头失效原因。分析结果表明,弯头中的疏松缺陷是造成弯头开裂的主要原因。其中,弯头中的疏松缺陷起源于原材料在冶炼过程中存在的夹渣,因后续工艺未能及时发现和清除,在弯头成型过程中裂纹缺陷恶化,因此在很小水压强度试验压力下裂纹起源于弯头内表面,主裂纹沿晶界间疏松缺陷向心部开裂扩展,主裂纹两侧及尖端周围有沿晶开裂二次裂纹,最终部分裂纹贯穿整个壁厚,发生了泄漏事故。 相似文献
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In a recent paper, the Ritz method with simple algebraic polynomials as trial functions was used to obtain an eigenvalue equation for the free vibration of a class of homogeneous solids with cavities. The method presented is here extended to the study of a class of non-homogeneous solids, in which each solid is composed of a number of isotropic layers with different material properties. The Cartesian coordinate system is used to describe the geometry of the solid which is modelled by means of a segment bounded by the yz, zx and xy orthogonal coordinate planes and by two curved surfaces which are defined by fairly general polynomial expressions in the coordinates x, y and z. The surface representing the interface between two material layers in the solid is also described by a polynomial expression in the coordinates x, y and z. In order to demonstrate the accuracy of the approach, natural frequencies are given for both a two- and three-layered spherical shell and for a homogeneous hollow cylinder, as computed using the present approach, and are compared with those obtained using an exact solution. Results are then given for a number of two- and three-layered cylinders and, to demonstrate the versatility of the approach, natural frequencies are given for a five-layered cantilevered beam with a central circular hole as well as for a number of composite solids of more general shape. 相似文献
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通过分析膨胀套在实际使用产生滑移受阻现象、卡死现象原因的实质,并在分析产生问题原因的基础上提出了改进措施即:增加导向机构。 相似文献
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The distribution of elements in yeast cells was measured on freshly prepared, freeze-dried cryosections and compared with the distribution obtained on the same sections after storage for 20 months in a vacuum below 2·6 kPa. The average concentration of phosphorus remained unchanged but was equalized throughout the cells, i.e. it migrated from vacuoles into the cytoplasm and mitochondria. Zinc remained preferentially localized in the vacuoles, but the ratio between vacuolar and cytoplasmic zinc concentrations decreased about three-fold. Cytoplasmic and mitochondrial concentrations of potassium remained unchanged while partial release from the vacuoles and subsequently from the cells was observed. This resulted in a homogeneous distribution of potassium in the cells after 20 months and some of the vacuolar potassium appeared in spectra of formvar film measured several micrometres from the cells. A large increase in the sodium (from 160 to 360% more than in fresh sections), magnesium (from 110 to 200% more) and sulphur (from 70 to 350% more) contents was observed in all cellular compartments (except for vacuoles, where only a 20% increase in the magnesium content was observed), while chlorine was almost completely released from the cells. The limitations of the use of long-term vacuum-stored cryosections for electron micro-probe analysis of cells are discussed. yeast. 相似文献
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随着科技高速发展,各种高科技含量的设备和加工方法越来越多地运用在机械加工中,但最简单经济的加工方法仍是机械加工的首选.本文概述了在圆周8等分工位上钻孔的装置,该装置结构简单,加工方便,对操作者的技术水平要求也低;同时,还适用于圆心同在圆周8等分工位上且直径不同的孔. 相似文献