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通过改变激光脉冲能量和激光聚焦位置,进行了激光诱导向前转移铜箔的实验,并通过超景深三维显微镜和扫描电子显微镜对基片和约束层上沉积的铜箔进行了观察,探讨了激光脉冲能量和激光聚焦位置对铜沉积效果所产生的影响,在此基础上研究了激光诱导向前转移的机理。研究结果表明,在石英玻璃基片上沉积的铜箔直径最小可达10μm,远小于激光光斑直径;在约束层上也沉积有铜箔,即同时出现了激光诱导向后转移的现象;光脉冲能量增大,石英玻璃上沉积的铜箔逐渐分散,尺寸逐渐增大,而且呈环形分布;通过调节靶材离焦点距离,可以使环形消失,并使沉积尺寸降到激光光斑尺寸以下。最后成功实现了微细阵列的激光诱导沉积。 相似文献
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利用石墨烯的电导率可以通过电压调节的特性,研究了一种基于单层石墨烯的太赫兹调制器。为了提高太赫兹-石墨烯相互作用强度,调制器采用一种石墨烯-金属复合结构。全波电磁数值仿真结果表明,在反射工作模式下,该器件在3.5 THz的调制深度大于90%。采用平面半导体工艺,实现了调制器原型器件,并对其反射谱进行了测试,实验数据与仿真结果相符,这为以后实现高质量的太赫兹调制器奠定了基础。 相似文献
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为了改善柔性电容式传感器灵敏度与测量范围的问题,提出了一种易制备、无微结构的制备方法。以硅橡胶为柔性基底,碳纳米管和石墨烯为导电填料,采用机械共混和热固化工艺制备了柔性碳基介电层,选用铜箔作为传感器上下电极。研究分析了碳基填料和固化温度对介电层灵敏度与弹性模量的影响,并通过万能试验机与数字电桥构成测试回路对传感器传感性能进行测定分析。实验结果表明,混合填充与单组分填充相比灵敏度提高约10倍,较高的固化温度可以有效降低弹性模量;在30 kPa压力下灵敏度高达1.092 kPa-1且在循环载荷下表现出良好的稳定性,响应时间和恢复时间分别达到300 ms与260 ms,并且拥有较低的迟滞特性。 相似文献
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为解决目前卷材剪切机不能满足薄型化电子铜箔剪切质量要求的难题,针对电子铜箔材质特性,研究了一种基于偏心轮连杆机构设计的切刀机构.首先,从偏心轮传动机理和摆杆的联动两方面,详细地阐述了切刀机构的运行原理;然后,对切刀啮合点的受力情况进行了分析;最后,通过样机实际测量的经验数据分析和运用Matlab计算数据分析,完成了切刀机构的优化设计.研究结果表明,根据铜箔厚度的不同,通过适当地调整切刀机构中摆杆及刀架的技术参数,可改善铜箔的剪切效果,解决了铜箔剪切过程中易起皱、产生铜粉的问题,满足了电子铜箔剪切的特殊要求. 相似文献
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石墨烯是已知最薄的二维材料,其厚度仅为0.335 nm。与传统固态纳米孔相比,石墨烯纳米孔传感器具有极高的检测分辨率。通过MEMS工艺与二维材料湿法转移工艺组合制造出石墨烯薄膜芯片。其中,使用Raman和氦离子显微镜成像判别转移后石墨烯质量。随后,采用氦离子束刻蚀技术在单层石墨烯薄膜上制造出直径为20 nm的石墨烯纳米孔。测量出石墨烯纳米孔传感器电流-电压关系,与经典纳米孔电导理论符合。本论文研究表明单层石墨烯纳米孔传感器检测可检测出牛血清蛋白(Bovine serum albumin, BSA)水平,垂直和旋转三种过孔形态,阻塞电流值分别为1200 pA, 150 A, 650 pA。同时也辨识出多分子同时过孔信号,BSA分子排列成三角形状穿过石墨烯纳米孔。 相似文献
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从过程序列、过程链到过程流 总被引:6,自引:0,他引:6
研究了产品开发设计过程集成的两项关键技术,即建立面向产品全生命周期的虚拟产品模型,以及项目模型、工作流模型和产品模型的集成问题,提出了虚拟产品模型的结构,以及项目模型、工作流模型和产品 集成框架。在此基础上,可以进一步开发出实现上述功能的软件系统。 相似文献
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在制定零件机械加工工艺过程中,当定位基准与设计基准不重合时,需要建立工艺尺寸链来计算工序尺寸。当零件同一方向上设计尺寸较多时,定位基准需要多次转换才能保证这些设计尺寸,其工序尺寸的确定就变得比较复杂。本文通过实例介绍一种基于工艺过程的工序尺寸的确定方法,用这种方法建立工艺尺寸链、确定工序尺寸非常实用,具有一定的推广价值。 相似文献
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工艺数字化系统中的工序质量管理 总被引:8,自引:2,他引:6
工序质量管理是工艺数字化系统中的一个子系统。该子系统提供了采集器采集和手工输入两种数据输入方式,并经过一系列统计分析得到与质量特性数据有关的完整图表。该图表可帮助质量管理人员及时准确地发现加工过程中的质量问题,进而实现对工序质量控制点的管理,并通过数据库实现了与工艺数字化系统中其他子系统的集成。 相似文献
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An optimal approach for process tolerance balancing is presented. The new approach is based on process capabilities and is
to be used in the stage of process planning. A nonlinear programming model is used to simultaneously optimise process tolerances
of required operations. In the optimisation model, the objective function is to minimise the total manufacturing cost with
different weighting factors. Using the estimated standard deviations of the dimensions and the manufacturing cost-tolerance
functions, the constraint equations for the process tolerance chains and the manufacturing capability indices are established,
together with a model for the economical tolerance bounds of machine tools. A practical example was used to verify the usefulness
of the proposed approach. The results of the comparative study show that the proposed approach is more advantageous in relaxing
tolerance requirements and in reducing scrap rates generally, compared with the existing methods.
ID="A1"Correspondance and offprint requests to: Dr Y. Gao, Department of Mechanical Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon,
Hong Kong. E-mail: meygao@ust.hk 相似文献
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将工序尺寸和工序废品分为两类;对两类工序尺寸及其超差品的特征、产生原因和处理办法进行了讨论;同时对两类工序尺寸所要求的工序能力指数提出了新的见解. 相似文献
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Hee-Woong Kim 《International Journal of Flexible Manufacturing Systems》2000,12(4):275-290
Organizational change has been a key component in enhancing performance and organizational design. Previous process-oriented organizational change methods, however, focused on simplifying process flow without examining how it affects other organizational elements. Since an organization consists of several interdependent elements, a change within an organization can affect the other dependent organizational elements. Lack of coordination within an organization can result in unexpected poor performance and high coordination cost. In this research, we suggest a coordination theory approach to organizational process change by applying the Massachusetts Institute of Technology Process Handbook with simulation technique. For the validity test, we applied the Process Handbook to a real hospital. From the application case, we saw that the proposed approach is useful in minimizing the risk of the change project by validating change alternatives using simulation technique, coordinating the dependent organizational elements, and managing change effects on other organizational elements. In this article, we discuss the proposed method and the transformation of a new organizational design to the workflow system development. 相似文献
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C.-Y. Chou K.-W. Huang C.-H. Chen 《The International Journal of Advanced Manufacturing Technology》2002,20(10):754-757
Wen and Mergen have presented a method of determining the optimum process mean for a poor process. Wen and Mergen balance
the costs of products out-of-specification by setting the optimum process mean in the short term. However, they have not considered
the quality loss for products within specification in the model. In this paper, a modified Wen and Mergen’s cost model is
proposed with linear and quadratic asymmetrical quality loss of products within specification for determining the optimum
process mean. Two specific conditions are considered:
1. The process standard deviation is proportional to the process mean (constant coefficient of variation).
2. The autocorrelated process.
ID="A1"Correspondance and offprint requests to: Dr C.-H. Chen, Department of Industrial Management, South Taiwan University of Technology, 1 Nan-Tai Street, Yung-Kang City,
Tainan 710, Taiwan. E-mail: chench@mail.stut.edu.tw 相似文献
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Yeong-Hoang Lee Chiu-Chi Wei Ching-Liang Chang 《The International Journal of Advanced Manufacturing Technology》1999,15(9):655-659
A novel formulation for designing process tolerances to maximise the process capability index is presented in this study.
The proposed model simultaneously optimises the process capability of each operation, and is consolidated into a single objective
fuzzy programming. A step fuzzy membership function is employed to represent the lower and upper bounds of the process capability
index, the problem is then solved by finding the maximum value of the fuzzy number. This study is believed to be the first
attempt to design process tolerance with the maximisation of process capability index. A comparison of the results shows that
the fuzzy model is suitable for assigning tolerances to an existing process. 相似文献