共查询到20条相似文献,搜索用时 109 毫秒
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为了增加实际网络系统连接增益、减少网络连接成本, 提出了一种基于网络效率和平均连接度的网络拓扑连接优化控制方法, 该方法利用网络效率来表征网络连接收益、用网络平均连接度来表征网络连接成本, 并提出了其计算优化算法, 该算法的时间复杂性为O(Mpn2). 实验分析表明, 可以采取一定的方式对实际复杂网络拓扑连接进行优化控制, 小世界和无标度网络均存在一个最佳的网络平均度值能够使网络连接增益达到最大.
关键词:
复杂网络
拓扑连接
优化控制
连接增益 相似文献
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保偏光纤的连接损耗和消光比分析 总被引:1,自引:0,他引:1
采用模式分析法处理两保偏光纤在连接中各种几何不对准误差引起的损耗和消光比的计算问题,给出了数值求解的结果,该结论对保偏光纤的连接,熔接和耦合等具有一定的指导意义。 相似文献
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单模光纤连接损耗研究 总被引:7,自引:0,他引:7
本文从单模光纤高斯模场解析分析法入手,推出了单模光纤归一化频率与高斯模场直径的解析表达式,此后,导出了单模光纤连接中同时存在横向偏移,轴线倾斜,端面间隙,以及光纤直径不匹配时的连接损耗更加完整而普通的计算公式,从而为单模光纤连接器及单模光纤熔接机对准系统的设计提供了依据。 相似文献
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静息态脑功能连接分析是近年来脑研究的一个热点问题, 对于某些脑疾病的诊断及成因理解具有重要意义. 已有的脑功能连接研究基本上都假设功能连接网络在一段时间内是稳定不变的, 但越来越多的证据表明它应该是随时间动态变化的. 对25名被试睁眼和闭眼状态的64电极脑电生理信号, 采用独立成分分析、滑动时间窗、低分辨率脑电断层溯源、图论等方法和技术进行动态功能连接分析, 展现了睁眼和闭眼两种基线状态下视觉网络、默认网络等功能连接网络随时间的动态变化, 并对动态连接矩阵进行主成分分析得到了在整个时间段内具有代表意义的功能连接模式. 该结论支持和补充了传统稳态脑功能连接的研究, 也将为相关实验设计以及脑电信号临床研究提供基线选择依据. 相似文献
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刘喜川黎军王凯林伟雷海乐 《低温与超导》2018,(11):26-30
在基于G-M制冷机的低温系统中,为了在降低样品座振动幅度的同时保证传热效率,采用了在传热组件中增加软连接柔性传热进行三级减振。实验研究了G-M制冷机竖置状态下不同工艺连接形式的软连接对样品座传热效率和振幅的影响。实验对比结果表明,相比传统的螺接连接方式,过盈冷压的软连接方式在降低样品座振动的同时保证传热效率。在G-M制冷机竖置时样品座的最低温度可达6. 5K,温度稳定性为±1mK@15-18K,振幅优于±600nm。 相似文献
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关于电容器连接中的能量问题,是一个值得讨论的问题,本文就以程守洙主编的《普通物理学》第二册中的一个电容器连接的题目为例作一讨论.原题是这样的. 相似文献
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本报道了一种BPSCCO(2223)/Ag复合带的超导连接:将待连接的BPSCCO/Ag复合带的一宽平面Ag鞘部分掀开,彼此相向插入,并使暴露的BPSCCO芯相向叠接,在一定的单轴压力下进行冷压结,再经后续高温热处理。连接区在77.3K下能保持一定的超导载流能力。同时亦观察了连接区的I-V特性、抗弯曲应变和冷热疲劳应力的性能。 相似文献
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本文提出了一个基于随机行走和策略选择的复杂网络局域演化模型RAPA. 新节点加入系统不需要全局知识,而是通过随机行走构造局域世界;然后依据概率采用随机连接,"扶贫"连接或"亲富"连接策略,从局域世界中选择节点增加连接边;最终自组织演化具有幂律特点的复杂网络. 初步的解析计算和仿真实验都表明,RAPA模型不仅重现了具有小世界特性、整体上的无标度特性,还可以演化出小变量饱和以及指数截断等现象,同时也具有明显的聚类特性,并能够构造出同配或异配等不同混合模式的网络.
关键词:
复杂网络
模型
随机行走
策略连接 相似文献
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It is not easy to hermetically seal using anodic bonding on both sides of silicon-on-insulator (SOI) wafer. Taking this into consideration, we suggest an electrical feed-through method for anodic bonding on the both sides of SOI wafer. The suggested method is illustrated on the basis of vacuum package of a conventional two-dimensional (2-D) micro-scanner. Electric feed-through for anodic bonding and electrical interconnection through the glass/silicon interface to the 2-D micro-scanner in the package are presented. The proposed electrical feed-through method is investigated by characterizing bonding current. The bonding current characteristics show that the electric feed-through has formed electric field distribution required for double-side anodic bonding. The operation characteristics of packaged 2-D micro-scanner are also investigated, which show successfully performed electric interconnection between inside and outside of the package. The proposed method is an effective technique for double-side anodic bonding based package not only for micro-scanner but also for different mechanical oscillators such as accelerometer, gyroscope and etc. 相似文献
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During electrostatic bonding, anodic oxidation of the anode material, for instance silicon, is thought to be the essential step in the bonding mechanism, leading to the formation of a permanent, strong and vacuum-tight bond. Despite the perceived importance of this step in the bonding mechanism of this well-established bonding technique, there is little experimental evidence for anodic oxidation during electrostatic bonding. One reason is that a thin (approximately 10–20?nm) amorphous anodic oxide layer is difficult to detect adjacent to an amorphous cation-depleted glass. Here, silicon–Pyrex and aluminium–Pyrex electrostatic bonds are made and the anodic oxidation process is studied directly using transmission electron microscopy. The consumption of silicon is demonstrated by the movement of the crystalline–amorphous interface compared with a marker under the original silicon–Pyrex interface. The formation of an anodic silica layer can also be demonstrated using electron-energy-loss spectrometry. An amorphous reaction layer 5–20?nm thick is formed during the bonding cycle. For aluminium anode materials bonded at 450°C a nanocrystalline γ-Al2O3 reaction layer is formed, which can be readily detected by transmission electron microscopy. At a bonding temperature of 350°C, no such crystalline reaction layer can be detected between Pyrex and aluminium. 相似文献
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As the key part of chip-scale atomic clocks(CSACs), the vapor cell directly determines the volume, stability,and power consumption of the CSAC. The reduction of the power consumption and CSAC volumes demands the manufacture of corresponding vapor cells. This overview presents the research development of vapor cells of the past few years and analyzes the shortages of the current preparation technology. By comparing several different vapor cell preparation methods, we successfully realized the micro-fabrication of vapor cells using anodic bonding and deep silicon etching. This cell fabrication method is simple and effective in avoiding weak bonding strengths caused by alkali metal volatilization during anodic bonding under high temperatures.Finally, the vapor cell D2 line was characterized via optical-absorption resonance. According to the results,the proposed method is suitable for CSAC. 相似文献
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Stable 85Rb micro vapour cells: fabrication based on anodic bonding and application in chip-scale atomic clocks
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We describe the microfabrication of 85 Rb vapour cells using a glass-silicon anodic bonding technique and in situ chemical reaction between rubidium chloride and barium azide to produce Rb.Under controlled conditions,the pure metallic Rb drops and buffer gases were obtained in the cells with a few mm 3 internal volumes during the cell sealing process.At an ambient temperature of 90 C the optical absorption resonance of 85 Rb D1 transition with proper broadening and the corresponding coherent population trapping (CPT) resonance,with a signal contrast of 1.5% and linewidth of about 1.7 kHz,have been detected.The sealing quality and the stability of the cells have also been demonstrated experimentally by using the helium leaking detection and the after-9-month optoelectronics measurement which shows a similar CPT signal as its original status.In addition,the physics package of chip-scale atomic clock (CSAC) based on the cell was realized.The measured frequency stability of the physics package can reach to 2.1×10 10 at one second when the cell was heated to 100 C which proved that the cell has the quality to be used in portable and battery-operated devices. 相似文献
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A novel fusion bonding method between silicon and glass with Nd:YAG laser is described.This method overcomes the movable mechanical parts damage caused by the electrostatics force in micro-electronic machine-system(MEMS)device during the anodic bonding. The diameter of laser spot is 300 μm,the power of laser is 100 W,the laser velocity for bonding is 0.05 m/s,the average bonding tension is 6.3 MPa.It could distinctly reduce and eliminate the defects and damage,especially in movable sensitive mechanical parts of MEMS device. 相似文献
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M. Waris 《Applied Surface Science》2006,252(20):7327-7330
This work demonstrates anodic bonding of Zerodur glass having very low co-efficient of thermal expansion (CTE) to Si, Zerodur glass to thermally grown silicon dioxide on silicon and Pyrex glass to Ge. Bonding results, using point cathode contact and plate cathode contact configurations, are discussed. Bonding parameters, i.e. applied dc voltage, temperature and bonding time were determined. Heating and cooling rates for crack-free bonding of Zerodur glass were also determined. 相似文献
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This paper describes a micro thermal shear stress sensor with a cavity underneath, based on vacuum anodic bonding and bulk micromachined technology. A Ti/Pt alloy strip, 2μm×100μm, is deposited on the top of a thin silicon nitride diaphragm and functioned as the thermal sensor element. By using vacuum anodic bonding and bulk-si anisotropic wet etching process instead of the sacrificial-layer technique, a cavity, functioned as the adiabatic vacuum chamber, 200μm×200μm×400μm, is placed between the silicon nitride diaphragm and glass (Corning 7740). This method totally avoid adhesion problem which is a major issue of the sacrificial-layer technique. 相似文献
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采用高速PIN光电探测器和高带宽的数字存储示波器,实时检测透射光脉冲和散射光脉冲的变化特征,并将之用作材料破坏的光学判据,测量得到K9玻璃在1.06μm纳秒脉冲激光作用下的能量损伤阈值约18mJ,相应的能量密度阈值为1.0kJ/cm2。通过分析透射光脉冲和散射光脉冲的特征,给出了材料的破坏时刻,并推断出K9玻璃所能承受的极限光强为1015W/m2。研究了能量透过率与泵浦能量的关系,并初步探讨了透明材料的破坏机理。结果表明:在多纵模激光的作用下,透明光学材料破坏是电离击穿与自聚焦效应综合作用的结果。 相似文献
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Sacrificial anodic oxidation is used to thin silicon wafer bonding substrates. Chemical solutions, sensitive to the periodic strain field present in the upper ultra-thin silicon layer, are employed for selective etching. Subsequent scanning tunnel microscopy observations reveal a square array of trenches corresponding to the buried screw dislocation network initially formed at the bonding interface. The influence of the initial thickness and the annealing of the ultra-thin film on roughness and trench depth of the nanopatterned substrates are examined. Germanium growth experiments are performed in order to show the self-organization character of resulting structured surfaces. 相似文献