灌注密封材料——GD-406室温硫化硅橡胶

近几年来,我厂在密封插座上采用晨光化工厂GD-406单组份室温硫化硅橡胶作为密封层的密封材料,在飞机座舱与照相舱间使用,完全符合密封插座技术条件的要求。 密封插座主要技术性能是: 1.长期工作温度:A等级-55～ 150℃;B等级-55～ 100℃。允许插座温升 50℃。     

奥迪兰勃8000S合并放大器

奥迪兰勃(Audiolab 8000S)是一台很特别的遥控式合并放大器,没有唱头输入,没有音调控制,简洁的通路,沿用了久享盛名的8000A大电流MOSFET功率管,全密封NOBLE高级音量控制器,全密封耳机插座和其它高级元件,所有接线柱和插座均经镀金,为适应大电流输出,采用了两组宽间距大型扬声器接线柱以防止短路。前级放大采用Audiolab秘而     

三芯密封塞密封性实验装置设计研究及应用

阐述石油测井仪器中三芯密封塞的组成及特点，设计了检验三芯密封塞在高温高压时密封性能的试验装置，包括三芯装配装置，装配三芯装配装置的活塞缸，计算了活塞缸中活塞行程，计算了甲基硅油体积在高温下的变化。同时对密封圈的压缩量进行了校核。     

基于光固化的液芯光纤及其性能

研究了液芯光纤及其芯液的性能,以及液芯光纤包层裂纹损伤的修复效果和修复原理。结果表明：该液芯光纤具有数值孔径大,传光性好等特点;芯液的光固化速度快,能够修复光纤包层裂纹,延长了光纤的使用寿命。该液芯光纤不仅可用于传感,而且由于芯液的特殊性使其能够用于光纤智能复合材料的自诊断和自修复。     

氦液面测量用电容传感器的设计研究

本文主要介绍了“YR—80—Ⅱ型电容式低温液面计”的一次敏感元件——电容传感器的研制和设计情况。对电容传感器的工作原理、结构设计、装配工艺等方面做了比较详细地叙述。电容传感器探头外径为φ10mm、测量范围0～1000mm、漏热对液氦的损耗量为0.75 1/24h、内电极,外电极以及零位电容补偿线之间的绝缘电阻大于20MΩ。在内电极引出管中,增加了零位电容补偿线,较好地克服了内电极引线分布电容变化对液面测量的影响;在外电极(外管)与八芯密封插座之间,采用了导热系数小的尼龙材料做连接座,减小了电容传感器上部漏热对液氦的损耗。     

真空正压转轴密封结构设计与分析

本文重点介绍了作者在实际应用过程中设计的两种真空正压转轴密封结构、性能及特点。利用胶芯弹性盘根作为密封材料设计的新型填料转轴密封结构,在1.3×10-4 Pa～2.5 MPa较宽的压力范围内具有极佳的密封性能,结构具有低摩擦、低漏率、无污染的特性,自润滑性能良好,密封效果持久可靠。     

新技术新产品介绍

新技术新产品介绍１．水下加速度计英国Ｍｏｎｉｔｒａｎ公司最近开发了ＭＴＷ—Ｗ系列的加速度传感器。这一系列的加速度计可用于淡水或海水中的水下测量。加速度计密封件的防水性符合ＩＰ６８标准。其钢外壳接头是焊接的，电气连接采用与外界隔绝的插头插座密封组件，或...     

共混法制备吸燃油自密封复合材料及其性能研究

燃油储存容器破坏后导致的燃油泄露事故不容忽视,本工作通过共混改性将高吸油树脂引入聚氨酯基体中,制备了吸燃油自密封复合材料以用作储油容器的防护涂层,探究了高吸油树脂粒径对自身吸油性能及复合材料力学性能的影响规律,分析了复合材料的自密封机理并观测了其自密封效果,最后讨论了高吸油树脂含量对复合材料粗糙度、附着力、动态力学性能、耐燃油性能的影响。结果表明：高吸油树脂的粒径越小,其吸油速率越快,复合材料的力学性能越好。高吸油树脂的加入使得复合材料的粗糙度增加,而附着力及阻尼性能略有下降。所制备的吸燃油自密封复合材料仅需5 min便可密封直径为1.5 mm的缺口,在储油容器的防泄漏领域具有潜在的研究价值。     

车组压裂车MCB优化接线的讨论

压裂车组在施工过程中会因为操作不当或者车辆本身故障,出现压裂车控制程序混乱的情况,导致压裂车档位或者各种参数的丢失,必须刷新MCB控制板的程序,才能恢复正常,但是刷新过程比较繁琐,还容易导致元器件的损坏。为解决这一难题,我们加装了一个三芯座和一个三相开关,通过开关来控制程序刷新时接线端的切换,编程线直接通过三芯插座相连,避免了编程线接头的多次接换,并且简单快捷,保证了MCB控制板的正常使用。     

2002年家庭及类似用途插头插座(含转换器)产品质量国家监督抽查结果

插头插座产品虽小,其质量却直接关系到千家万户的安全。据有关部门统计,插头插座产品质量不高是近年来引发电器火灾的原因之一。针对这种状况,2002年第2季度,国家质量监督检验检疫总局对家庭及类似用途插头插座(含转换器)(以下简称插头插座)产品质量进行了国家监督抽查。本次抽查涉及北京、上海、广东、浙江、江苏、四川等6个省、直辖市132家企业生产的132种插头插座产品,合格79种,产品抽样合格率为59.8％。     

PE软管封口技术研究进展

目的对目前PE薄片管材的主流热封方法进行归纳总结,为后续的研究提供依据。方法综述PE薄片作为软管热封的优缺点,分析PE薄片管材的热封和其他因素的影响,探讨目前比较先进的灌装封尾机构的现状。结果 PE大多用于膏体的灌装上,其密封性能除了与材料有关外,也与其密封条件有很大关系,其密封方法一般采用热封方式。PE薄片管材热封后的性能与热封的三个要素(热封时间、温度和压力)有关,其中最重要的是热封温度。结论目前企业用得最多的热封方法是内加热,PE薄片管材采用水平封尾更加稳定。热封尾工艺要求达到一定的机械强度和足够的密封性。     

Development of Family of Super Convergent Shear Deformable Finite Elements for the Analysis of Sandwich Beams with Soft Core

Sandwich structures are widely used in aerospace and naval industries as they are light in weight and have high energy absorption capacities. Sandwich beams with soft core are the most commonly used structures in many applications. Analysis of sandwich beams is the key in its design and the development of new family of super convergent shear deformable finite elements are presented in this article. In this article, formulation of three different Super Convergent shear deformable finite elements with 4, 7, and 10 degrees of freedom respectively, for analysis of the sandwich beams with soft core are presented. The formulation considers the top, bottom face sheets and core as separate entities and are coupled by beam kinematics. The performance of these elements are validated by results available in the published literature. The article highlights the issues with the traditional elements for modeling sandwich beams and the advantages of the elements developed, in particular wave propagation analysis, are addressed in this article.     

Ultrasonic Sealing of Flexible Packaging Films – Principle and Characteristics of an Alternative Sealing Method

The closure process for packaging is a key process. It ensures the protective function of packaging and assures the packaged goods a long life. In this context, efficient and reliable sealing processes are essential for the production of sustainable packages. In this paper, several characteristics of the ultrasonic sealing process will be discussed and accompanied by experimental results. The introduction provides an insight into the ultrasonic sealing process, its heating mechanisms and the process steps. A comparison is made with conduction sealing. Furthermore, basic principles of heating and energy dissipation are related to the influences of the sealing parameters on the seam strength. The experimental studies were carried out on typical packaging films, such as polyamide‐polyethylene laminates. The seam strength in ultrasonic sealing is compared with that in conductive sealing. A lower seam strength was found for ultrasonic sealing in all the tested films. Furthermore, the sealing behaviour of the packaging films contaminated with different kinds of foods was analysed for both sealing methods. Although the ultrasonic sealing method has marginal advantages for bulk materials such as wheat flour, conduction sealing was shown to be better for other products. A comparison of the energy consumption during the ultrasonic and conduction sealing verified the advantages of ultrasonic sealing. In particular for thick packaging films, the amount of energy required for bonding is significantly lower than for conduction sealing. In summary, this paper provides a survey of the characteristics of the ultrasonic sealing method in packaging applications – its advantages and limitations. Copyright © 2011 John Wiley & Sons, Ltd.     

镁铝合金表面锶磷化膜的改性及其腐蚀性能研究

利用化学沉积法在镁铝合金表面构筑锶磷化膜,以氢氧化钠和硅酸钠为原料配制磷化膜封孔处理液,对镁合金表面锶磷化膜存在的裂纹和孔洞等缺陷进行封孔处理。通过元素分析及扫描电子显微镜发现改性膜层表面具有Sr、P、O以及Si元素,硅酸钠对锶磷化膜具有良好的封孔作用。通过膜层厚度检测,证明封孔后的锶磷化膜厚度没有发生显著变化。封孔后的锶磷化膜极化电阻比封孔前提升了4倍,而腐蚀电流仅为封孔前的1/3,封孔后膜层的耐腐蚀性能显著提升。     

电动热封口式垃圾桶的设计

为避免垃圾桶中的垃圾直接与人体接触,减少垃圾对环境的污染,基于电动热封口技术,设计了一种电动热封口式垃圾桶.以MSP430单片机为控制核心,采用梯形丝杠传动技术,将步进电机的转动转换为垃圾桶压条装置的直线运动;在压条装置上辅以合理的电路设计以及双层电热丝结构,实现对塑料垃圾袋无间隙、低噪音封口;选用LCD12864液晶...     

Contact mechanics and friction in PTFE coaxial sealing systems

The paper addresses the friction process in coaxial sealing systems of hydraulic cylinders based on studies starting from an analysis of the energy efficiency ensured by these actuators. Notwithstanding the main purpose of a sealing system, namely to prevent fluid leakage, energy related aspects should also be considered, materialised in the efficiency of the hydraulic cylinders. The efficiency of hydraulic cylinders depends on the magnitude of the friction forces caused by the sealing systems. In this respect the paper focuses on discussing studies concerning the types of friction in the sealing tribosystem and on establishing methodologies for the analytical and experimental determination of the friction forces introduced by coaxial sealing systems. The obtained results yield the conclusion that coaxial sealing systems generate friction forces several times smaller than those caused by other sealing types, thus ensuring a higher efficiency to hydraulic cylinders equipped with such sealing elements.     

Fabrication of microgel particles with complex shape via selective polymerization of aqueous two-phase systems

Microgel particles are formed from aqueous-two-phase-system (ATPS) droplets in poly(dimethylsiloxane) (PDMS) microfluidic devices. The droplets consist of a dextran core and a photopolymerizable poly(ethylene glycol) diacrylate (PEGDA) shell. Upon UV exposure, the ATPS droplets undergo a shape-transformation yielding PEGDA microgel particles containing a socket.     

Failure Analysis of a Fractured Wrench Socket

Failure of a 13/16 in. wrench socket while hand tightening a socket was investigated using hardness test, optical microscopy, scanning electron microscopy, and energy dispersive spectroscopy techniques. Hardness and microstructure of the fractured socket are compared with those of other original (unfailed) wrench sockets from other manufacturers. Wrench material is a low carbon steel, and socket was manufactured in a powder metallurgy (PM) process. Results of this analysis indicate that non-uniform socket wall thickness, poor socket geometric design featuring sharp corners forming stress raisers, and poor sintering step in the PM process leaving unsintered particles were causes of the socket failure. The presence of the inclusions containing contaminants such as S and Al on the socket fracture surface may have played a role in this failure.     

Effect of submicron admixtures on mechanical and self‐healing properties of cement‐based composites

This study presents the development of novel submicron super absorbent polymers (SAPs) used as admixtures in cement‐based matrices with significant advantages over conventional products. The produced SAPs were characterized in respect of their morphology and composition, while their water absorption capacity was determined in different electrolyte solutions. The hybrid core‐shell spherical structure of the fabricated materials offered significant compatibility enhancement with cement while the workability of the mixture was maintained. The assessment of the cement‐based composites including SAPs revealed that their flexural strength increased by 78%. Self‐healing/sealing behavior was assessed by monitoring the crack sealing via SEM, elemental analysis of the healing products, and determination of the water absorbance coefficient for different times of treatment. The cement/SAPs composites with a concentration of SAPs 2% by weight of cement exhibited self‐healing/sealing responsive capability when an artificial crack was induced. According to the SEM characterization, the crack demonstrated complete healing for the better part of its length after 28 days of treatment.     

A triangular plate element for thermo‐elastic analysis of sandwich panels with a functionally graded core

A sandwich construction is commonly composed of a single soft isotropic core with relatively stiff orthotropic face sheets. The stiffness of the core may be functionally graded through the thickness in order to reduce the interfacial shear stresses. In analysing sandwich panels with a functionally gradient core, the three‐dimensional conventional finite elements or elements based on the layerwise (zig‐zag) theory can be used. Although these elements accurately model a sandwich panel, they are computationally costly when the core is modelled as composed of several layers due to its grading material properties. An alternative to these elements is an element based on a single‐layer plate theory in which the weighted‐average field variablescapture the panel deformation in the thickness direction. This study presents a new triangular finite element based on {3,2}‐order single‐layer theory for modelling thick sandwich panels with or without a functionally graded core subjected to thermo‐mechanical loading. A hybrid energy functional is employed in the derivation of the element because of a C¹ interelement continuity requirement. The variations of temperature and distributed loading acting on the top and bottom surfaces are non‐uniform. The temperature also varies arbitrarily through the thickness. Copyright © 2006 John Wiley & Sons, Ltd.