共查询到19条相似文献,搜索用时 109 毫秒
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电热激励微悬臂梁谐振器输出电压影响因素研究 总被引:2,自引:0,他引:2
制作了电热激励硅 /二氧化硅双层微悬臂梁谐振器。对影响谐振器输出电压的因素研究结果表明 :减小梁宽度、硅层厚度、环境气压和温度 ,可增大微悬臂梁谐振器输出电压 ;输出电压随激励功率增加而增大 ;谐振器输出电压与谐振器根部压敏电桥电源电压成正比。最后论述了提高谐振器输出电压的可行途径 相似文献
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硅微机械梳齿静电谐振器的建模与分析 总被引:5,自引:2,他引:3
基于参数化的计算机辅助设计(CAD)软件,对硅微机械梳齿静电谐振器进行了实体建模,以有限元分析软件为工具,进行了谐振器的模态分析,静态分析和谐响应分析,初步揭示了谐振器的静、动态特性,有助于改善设计效率和质量,展示了计算机辅助工程(CAE)技术在微机电系统(MEMS)研究中的重要作用。 相似文献
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微悬臂梁谐振技术检测溶液粘度的研究 总被引:1,自引:0,他引:1
提出了一种测量溶液粘度的微悬臂梁谐振技术。推导了溶液粘度与微悬臂梁的谐振频率的理论关系式,并利用原子力显微镜的微悬臂梁测量了不同质量分数的甘油溶液和蔗糖溶液的粘度。与落球法测量结果的比较表明,利用微悬臂梁谐振频率技术测量液体粘度的误差小于4%。这种方法不仅可以作为液体粘度的一般性测量方法,也可以通过检测溶液粘度变化来监测溶液中的化学反应。 相似文献
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针对当前压电驱动悬臂梁谐振器存在加工工艺复杂、成本较高的问题,该文提出了一种基于氮化铝支撑层的新型压电驱动悬臂梁层叠结构,它不仅能有效降低加工难度,还能在实现器件小型化的同时保持较高的品质因数。该文通过理论分析研究了固定频率下谐振器品质因数与器件尺寸设计的关系,并对比了不同支撑层材料对谐振器品质因数的影响。通过实验研究了电极尺寸设计对谐振器在真空中性能的影响,从而确定了工作在面外弯曲振动模式的压电驱动氮化铝基悬臂梁谐振器的最优设计。测试结果表明,在电极宽度占比为1,长度占比为2/3时,该谐振器表现出最好的性能,其品质因数为7 786,谐振频率为63.44 kHz,运动阻抗为66.70 kΩ。 相似文献
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We study the periodic structures that emerge beyond the instability threshold point in a semiconductor microcavity driven by a coherent stationary holding beam; the active layer of the microresonator is bulk GaAs or multiple quantum-well GaAs-AlGaAs. We apply a numerical technique to directly establish stationary solutions of the dynamical equations governing the electric field inside the cavity and the carrier density of the active material. To overcome the heavy computational requirements in the case of two-dimensional patterns, we consider small nonorthogonal integration grids, whose geometrical properties are those of the pattern elementary cell. We investigate the mechanism of pattern formation in connection with the modulational instability threshold, and we study, both in one and two dimensions, the bifurcation structure of various branches of patterns. We show how cavity solitons are related to periodic structures and we study the behavior that cavity soliton branches may exhibit in two dimensions. 相似文献
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I. A. Nakrap A. N. Savin Yu. P. Sharaevskii 《Journal of Communications Technology and Electronics》2006,51(3):303-310
The results of an experimental investigation of electrodynamic characteristics of a meander microstrip line with a ferromagnetic film are presented for different values of an external magnetic field. It is found that, in the presence of a ferrite film, higher-order modes caused by perturbation of corresponding modes of a multilayered meander line are excited in the passband of a higher-order mode of the meander line. These modes propagate in dielectric substrates of the meander line and the ferromagnetic film. The effect of transmission of the active power in the stopband of the meander line with a ferromagnetic film is discovered. This effect also arises in the case of excitation of magnetostatic waves. 相似文献
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《Broadcasting, IEEE Transactions on》2003,49(2):150-161
In designing a video broadcasting system, the delay preference of a user is traditionally regarded as unknown. In fact, such preference can be known upon user's arrival by employing some techniques such as: (i) delay-dependent charging, where users are offered different levels of pay-per-view (PPV) depending on the maximum delay they are willing to tolerate; or (ii) reservation, where a user specifies the exact play-time of a movie in advance, and he/she is charged according to the length of the reservation period. We explore, for the first time, the impact of such delay knowledge on request scheduling and system cost in terms of user loss and stream requirement. For delay-dependent charging, we propose "delay-aware broadcasting" (DAB) and its variant based on reservation (DAB-r), where allocation of server streams is driven by the delay tolerance of a user. DAB-r offers differentiated grade of services according to user PPV (and thereof classes). As compared with a system where user delay preference is not known, our schemes achieve substantially lower user loss rate, higher revenue, and better fairness. Regarding reservation system, we consider a scheme where clients can pre-buffer video data. Unicast streams are used to merge requests back to the on-going broadcast streams. We show that a reservation system achieves substantially lower stream requirement as compared to an on-demand system based on "patching". 相似文献
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最近几年,计算机技术发展迅速,信息化时代已经到来,人们生活水平也逐步提升。因此,使用者对机电设备的要求也越来越高,希望能够获得更为便捷、智能的机电设备。基于此,如何对机电设备进行自动化改造和维护是需要重点考虑的问题。本文以此为探究主题,首先简述机电设备自动化改造及维护的意义,接着对当前我国机电设备运行管理中存在的问题进行归类,最后有针对性的提出几点自动化改造及维护的策略。 相似文献
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In this paper, the quasicrystalline model and the differential evolution strategy are applied to analyze the effective electromagnetic properties of composite materials with aligned nonspherical inclusions. The relationship between the effective wave number, volume concentration, direction of wave propagation vector, and aspect ratio of the inclusion particle are numerically studied. It is found that composite materials with small inclusion particles behave like uniaxial material. In addition, we observed general effective anisotropy in composite materials with larger inclusion particles. 相似文献
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机械设计制造及其自动化是美国机械工程师在1984年所提出的一个机电一体化化名词,就是将计算机技术与机械设计制造相结合。机械设计制造及其自动化到今天为止一直是一门新兴学科,其中的内容还需要通过实践不断添加,让机械工业逐渐进入到机械自动化方向中。本文将以机械设计制造及其自动化学科与传统的机械设计制造学科区别作为研究对象,探索机械设计制造及其自动化学科所具有的优势,进而分析出我国机械设计制造及其自动化学科为了发展方向。 相似文献
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通过将证据理论引入到流量分类的决策模块中,提出了偏好度和时效度权值,并通过实测数据对多分类器识别模型进行验证,其结果表明该模型较好的克服了单分类器的片面性,通过对多个证据的融合来优化识别的结果。 相似文献