共查询到20条相似文献,搜索用时 187 毫秒
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本文首次采用有限元法对有调谐销钉的可调频薄基片矩形贴片微带天线的谐振频率和输入阻抗进行了计算,谐振频率的计算结果与实验结果符合很好。该方法原则上适合于任意数目调谐销钉置于任意位置的情形。可能会是处理带调谐销钉的最有效的方法。 相似文献
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矩形微带贴片天线的谐振频率 总被引:1,自引:0,他引:1
本文采用有限元法对有短路销钉的可调频薄基片矩形贴片微带天线的谐振频率进行计算,其计算结果与实验结果相当一致,该方法原则上适合于多个短路销钉置于任意位置的情形,可能是处理带短路销钉微带贴片天线的最有效的方法。 相似文献
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介质谐振器特性的有限元计算 总被引:1,自引:1,他引:0
本文应用有限元方法分析和计算了置于空气和不均匀介质中的圆柱形介质谐振器的谐振频率,以及介质谐振器与微带线的耦合参量。计算结果与现有文献的计算结果和实验结果相当吻合。 相似文献
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针对复合板结构中弯曲板波谐振频率计算相对复杂的问题,建立并分析了基于弯曲板波延迟线振荡器的理论模型,计算得到A0(0阶反对称)模式板波的谐振频率为41 MHz;为了验证理论分析的结果,利用有限元软件ANSYS建立了基于弯曲板波的延迟线振荡器的3D有限元模型,并对其进行了谐响应分析以及瞬态动力学分析。谐响应分析得到A0模式的谐振频率为37.2 MHz,与理论计算结果的相对误差为9.3%;瞬态动力学分析得到A0模式的谐振频率为39.1 MHz,与理论计算结果的相对误差为4.6%。计算和仿真为基于弯曲板波的延迟线振荡器的结构设计提供了重要的依据。 相似文献
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针对提高激光武器系统光束指向控制稳定精度的战术需求,设计了一款适用于光束指向快速反射镜的单轴半蝶形柔性铰链。首先,根据快速反射镜系统运动形式及功能需求,推演单轴半蝶形柔性铰链的物理模型;然后,采用基于卡氏第二定理的卡氏法简化并求解数学模型,并优化模型参数;最后进行有限元仿真与实验测试,并对单轴半蝶形柔性铰链机械谐振频率的理论计算、仿真分析以及实验测试结果进行分析比较。实验结果表明:单轴半蝶形柔性铰链工作方向机械谐振频率为165.29 Hz,满足设计指标要求。理论计算与实验测试结果相差1.3%,有限元仿真与实验测试结果相差3.2%。从而证明了单轴半蝶形柔性铰链结构形式合理,数学建模准确,为提高激光武器系统光束指向控制稳定精度提供了有力的支撑。 相似文献
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HRTEM study of new series of oxycarbonitrate superconductors (Cu,C,N)Sr2Ca(n - 1)Cu(n)O(y) (n = 1-6)
Anan Y Asaka T Hatano J Zhigadlo ND Takayama-Muromachi E Kimoto K Matsui Y 《Journal of electron microscopy》2001,50(6):457-463
Arrangements of Cu and anion groups (CO3 and NO3) in the charge-reservoir (CR) blocks of a series of new oxycarbonitrate superconductors (Cu,C,N)Sr2Ca(n - 1)Cu(n)O(y) (n = 1-6) were examined by means of electron diffraction and high-resolution transmission electron microscopy (HRTEM). The first three members with n = 1-3 [Tc = 33 K (n = 1), 91 K (n = 2), 90 K (n = 3)] show the 4a0-type superstructures with periodic arrangements, [-Cu-X-X-X-Cu-X-X-X-Cu-] (X = CO3, NO3), in the CR blocks. The third member (n = 3) partly contains the 2a0-type of superstructure with [-Cu-X-Cu-X-Cu] in the CR blocks. The fourth member with n = 4 (Tc = 113 K) contains only the 2a0-type of superstructure. The higher members, with n = 5 (Tc = 65 K) and n = 6 (Tc = 52 K), show no evidence of ordering in the CR blocks, suggesting random arrangements of Cu and anion groups. 相似文献
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The microstructures of Cu films deposited by the self-ion assisted, partially ionized beam (PIB) deposition technique under
two different accelerating potentials, 0 KeV and 6 KeV, are compared. The 6 KeV film shows a bimodal (111) fiber and (100)
fiber texture with an abundance of twin boundaries and a relatively large average grain size with a typical lognormal distribution.
The 0 KeV film consists of small, mostly (111) oriented grains with islands of abnormally large (100) grains. The controlling
factors for the abnormal growth of the (100) grains are discussed in relation to the observed microstructures, showing that
all factors necessary for abnormal (100) growth are present in the films. 相似文献
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This study compares the reliability of nMOSFETs with low- and high-doped ultra-thin body and buried oxide (UTBB) with fully depleted (FD) and partially depleted (PD) silicon on insulator (SOI). The high-doped devices display lower off-current leakage performance but more degradation in both hot-carrier stress (HCS) and positive bias temperature instability (PBTI) test at both room temperature and elevated temperature compared with the low-doped devices. The PBTI test indicates that the high-doped devices induce high tunneling leakage and that the degradation is highly associated with temperature. The degradation stabilizes with an increase in stress time. The thinner PD-SOI demonstrates low variation at the threshold voltage and low drive current under HCS. The FD-SOI has better drain leakage control than the PD-SOI. 相似文献
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Software-Defined Network(SDN)empowers the evolution of Internet with the OpenFlow,Network Virtualization and Service Slicing strategies.With the fast increasing requirements of Mobile Internet services,the Internet and Mobile Networks go to the convergence.Mobile Networks can also get benefits from the SDN evolution to fulfill the Sth Generation(5G) capacity booming.The article implements SDN into Frameless Network Architecture(FNA) for5G Mobile Network evolution with proposed Mobile-oriented OpenFlow Protocol(MOFP).The Control Plane/User Plane(CP/UP)separation and adaptation strategy is proposed to support the User-Centric scenario in FNA.The traditional Base Station is separated with Central Processing Entity(CPE) and Antenna Element(AE) to perform the OpenFlow and Network Virtualization.The AEs are released as new resources for serving users.The mobile-oriented Service Slicing with different Quality of Service(QoS) classification is proposed and Resource Pooling based Virtualized Radio Resource Management(VRRM) is optimized for the Service Slicing strategy with resource-limited feature in Mobile Networks.The capacity gains are provided to show the merits of SDN based FNA.And the MiniNet based Trial Network with Service Slicing is implemented with experimental results. 相似文献
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The cross-sectional reconstructed structure of Si (5,5,12) surface was, for the first time, observed using ultrahigh vacuum high-resolution transmission electron microscopy (UHV-HRTEM) profile view method. In the high-index region, two units of the (337) surface combine with one units of the (225) surface to complete one unit cell of (5,5,12) surface. The (337) unit at one side of the (225) unit is distinctly different from that at another side of (225) unit. The observed HRTEM images do not agree with the previous structural models of the (5,5,12) surface. We propose a new structure model of this surface using a TEM image simulation. Our model is agreement with the previously reported scanning tunnelling microscope images. 相似文献
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采用真空热蒸镀技术,制备了结构为ITO/NPBX(40nm)/rubrene(0.2 nm)/NPBX(5nm)/DPVBi(30nm)/TPBi:x%Ir(ppy)3(30nm)/LiF/Al的白光器件。利用Ir(ppy)3掺杂到电子传输层TPBi中,在掺杂层中提高了电子的迁移率,调整了空穴和电子的平衡,从而改善了白色有机电致发光器件的效率。当Ir(ppy)3的掺杂浓度为6%时,器件的电流效率最高,在驱动电压9 V时最大电流效率为10.66 cd/A,此时色坐标为(0.36,0.38);当电子传输层TPBi中不掺杂Ir(ppy)3时,白光器件的效率最低,在驱动电压10V时最大电流效率为1.69 cd/A,此时色坐标为(0.31,0.30)。掺杂浓度为6%的白光器件的电流效率是不掺杂白光器件的电流效率的6.3倍。 相似文献
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文章叙述了采用金属有机物四异丙基钛(Ti[OC3H7]4]为钛温,在外加热PCVD设备上沉积Ti(CN)涂层。并对涂层进行了其显微硬度测量,扫描电镜(SEM)观察和X射线衍射(XRD)分析。结果表明,此法制备的Ti(CN)涂层其显微硬度可达标15600N/mm2,膜层结构仍为在状晶,Ti(CN)晶体的d(200)随着炉温的升高和H2.N2比的增大在逐渐变化。 相似文献
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Koren U. Miller B.I. Tucker R.S. Eisenstein G. Bar-Joseph I. Miller D.A.B. Chemla D.S. 《Electronics letters》1987,23(12):621-622
We describe the structure and performance characteristics of an InGaAs/InP multiple-quantum-well (MQW) electro-absorption buried-mesa optical modulator. The device is fabricated with two metal-organic chemical-vapour-deposition (MOCVD) growth steps, wherein small-area circular (40?m diameter) PIN diodes are buried with Fe-doped semiinsulating (SI) InP regrowth. The modulator has a relatively low insertion loss (4.5 dB) with 25% modulation depth and very high modulation bandwith (5.3 GHz) operating at 1.62?m wavelength. 相似文献
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研究了一种基于激光干涉技术的瞬态热力学量测量方法,可用于测量由于光激发产生的瞬时反应热及反应体积。介绍了利用干涉技术测量化学反应热量及反应体积的基本原理。实验中以肌红蛋白(Mb)为研究对象,由于肌红蛋白受光激发后,会与CO发生化学反应,导致系统的热力学量发生变化,从而引起系统折射率的变化。折射率变化会引起干涉相位变化。通过测量相位变化,可以获得肌红蛋白受光激发后热力学量的变化信息。在273~301 K温度范围内进行了肌红蛋白与CO的反应实验,测量了肌红蛋白与CO在10-6~10-1s窗口的化学反应。测得的反应热量与体积分别为80 kJ/mol和10 mL/mol。 相似文献
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Blue phosphorescent organic light-emitting diodes(OLEDs) are fabricated by utilizing the hole transport-type host material of 1,3-bis(carbazol-9-yl)benzene(MCP) combined with the electron transport-type host material of 1,3-bis(triphenylsilyl)benzene(UGH3) with the ratios of 1:0,8:2 and 6:4,and doping with blue phosphorescent dopant of bis(4,6-difluorophenylpyridinato-N,C2)picolinatoiridium(FIrpic).The device with an optimum concentration proportion of MCP:UGH3 of 8:2 exhibits the maximum current efficiency of 19.18 cd/A at luminance of 35.71 cd/m2 with maintaining Commission Internationale de L’Eclairage(CIE) coordinates of(0.1481,0.2695),which is enhanced by 35.7% compared with that of 1:0 with(0.1498,0.2738).The improvements are attributed to the effective carrier injection and transport in emitting layer(EML) because of mixed host materials.In addition,electron and exciton are confined in the EML,and 4,4’,4’’-Tris(carbazol-9-yl)-triphenylamine(TCTA) and Di-[4-(N,N-ditolyl-amino)-phenyl]cyclohexane(TAPC) have the high lowest unoccupied molecular orbital(LUMO) energy level and triplet exiton energy. 相似文献