摘要：We report the design and simulation results of a solid-core Bragg fiber with 3-bilayer periodic cladding. The simulation results present single mode bandgap guidance, a large effective area of -400 μm2 around 1.08 μm, a very low bend loss of 0.038dB/m at 1.08μm even under tight bend radius （R = 4cm）, and excellent beam quality. The results indicate that the proposed fiber could be a competitive solution for high-power fiber laser applications.

摘要：二维(2D)材料正被广泛用于宽带响应光电探测器(PD).然而,基于2D材料的宽带响应PD通常对红外波长的响应较差.在此,我们报告了垂直PtSe_(2)/超薄Al_(2)O_(3)/Ge PD在近红外照明下的优异光响应性能.我们直接硒化沉积在Al_(2)O_(3)/Ge上的Pt膜以形成PtSe_(2)层.超薄Al_(2)O_(3)钝化层起到表面改性的作用,有效地削弱了光生载流子的复合.在1550 nm的光照下,我们的PtSe_(2)/超薄Al_(2)O_(3)/Ge PD的工作面积为50μm×50μm,并在零偏压下获得了4.09 A W^(-1)、32.6/18.9μs的大响应度和快速上升/下降时间.在-5 V的外加电压下,PtSe_(2)/超薄Al_(2)O_(3)/Ge PD的响应度和响应速度分别高达38.18 A W^(-1)和9.6/7.7μs.我们发现器件的工作面积对光响应特性有很大的影响.此外,我们证明PtSe_(2)/超薄Al_(2)O_(3)/Ge PD阵列在室温下显示出了优异的紫外、可见光和红外成像能力.我们的研究表明,PtSe_(2)/超薄Al_(2)O_(3)/Ge异质结在设计具有优异近红外响应性能的新兴宽带光电子器件方面具有巨大的应用前景.

摘要：Two kinds of compact electromagnetic band gap （EBG） structures are designed. A two layer compact EBG structure configured with cross spiral shape line inductors and interdigital capacitors is first presented. Because of its significantly enlarged equivalent inductor and capacitance, the period of the lattice is approximately 4.5% of the free space wavelength. By insetting several narrow slits in the ground plane, the bandwidth of the main bandgap is enhanced by nearly 19%. Further effort has been made for designing a three layer compact EBG structure. Simulation results show that its period is reduced by about 26% compared to that of proposed two layer EBG structure, and the bandwidth of the main bandgap is about 3 times as that of the proposed two layer EBG structure. The detailed designs including a two layer compact 3×7 EBG array with and without defect ground plane and the three layer EBG array are given and simulation results are presented.

摘要：A compact terahertz （THz） wave collimator is proposed, which works under the frequency from 2.4 THz to 2.7 THz with a photonic crystal （PC） slab based on the self-collimation effect. The plane wave expansion （PWE） method is used to calculate the dispersion surfaces and the equal-frequency contours （EFCs） and optimize the structure. The propagation of the THz waves in the structure is simulated and the normalized transmission is calculated by using the finite-difference time-domain （FDTD） method with perfectly matched layer （PML） absorbing boundary conditions. Numerical simulations show that the designed collimator has a good collimation property and a high transmittance.

摘要：推迟的很少层的热传导六角形的硼氮化物(h-BN ) 表试验性地用一个 noncontact micro-Raman 光谱学方法被调查。为单层(1L ) 的一阶的温度系数， bilayer (2L ) 并且九层(9L ) h-BN 表被测量是(当时， electrospinning 准备的 3.41 xide nanofibers 被期望减少了热电导率与体积样品相比。自从它包含复杂样品准备方法，热电导率正在质问的 nanofibers 的大小。在这个工作，我们在场对单个 nanofiber 的热电导率的大小合适的一个新奇方法。一 microelectro 机械(MEMS ) 设备被设计了并且制作了在单个 nanofiber 上执行热传导性大小。一个特殊 Si 模板被设计收集并且转单个 nanofibers 到 MEMS 设备名上吗？

摘要：Moving target detection （MTD） technique is designed to filtering out the clutters. The basis of the MTD digital signal processor is a bank of Doppler filters designed using FFT algorithm. For high pulse repetition frequency （HPRF）, it leads to a long time calculations and great complexity in hardware implementation. Frequency domain detector is represented by Welch method Realized Doppler filters bank which will reduce the time calculation. The proposed method enhances the target detection capabilities by providing higher detection probabilities or lower false alarm rates. The performance of the two systems, the traditional MTD-I and Welch method are compared from the viewpoint of probability of detection （Pd）, probability of false alarm （Pfa）. Computer simulation results are presented to support the superiority of the proposed technique.

摘要：To improve the robustness of the Low Earth Orbit(LEO) satellites networks and realise load balancing, a Cross-layer design and Ant-colony optimization based Load-balancing routing algorithm for LEO Satellite Networks(CAL-LSN) is proposed in this paper. In CALLSN, mobile agents are used to gather routing information actively. CAL-LSN can utilise the information of the physical layer to make routing decision during the route construction phase. In order to achieve load balancing, CALLSN makes use of a multi-objective optimization model. Meanwhile, how to take the value of some key parameters is discussed while designing the algorithm so as to improve the reliability. The performance is measured by the packet delivery rate, the end-to-end delay, the link utilization and delay jitter. Simulation results show that CAL-LSN performs well in balancing traffic load and increasing the packet delivery rate. Meanwhile, the end-to-end delay and delay jitter performance can meet the requirement of video transmission.

摘要：The paper puts forward a kind of online shopping system based on ASP. NET technology, including the establishment of data- base anti the design of the front web pages. The system uses Microsoft ASP. NEF as development platform, C as the server language, and Microsoft Visual Studio 2008 as the development tool. ADO. NET is used to connect with SQL SERVER 2000 database through the data- base controls. A variety of server controls are used to create the ASP. NET page to implonent the syste^n functions. The syston is designed in 3-Layer application which includes Presentation Layer （PL）, Busi- ness Logic Layer （BLL） and Data Access Layer （DAL）. The operation of the database is in DAL, the logic fimction is in BLL. So the amotunt of work in the development, the difficulty of system maintenance and the upgrading can be reduced. After being tested, the system meets the requirement of the users.

摘要：分析了I2C串行总线的数据传输机制;用VerilogHDL设计了随机读写模式串行总线控制器;在ModelSim6.2中进行了功能仿真;在XilinxISE9.1i集成开发环境中进行了综合、适配和FPGA器件下载调试;搭建外围电路对系统进行分析测试;并用Agilent16823A逻辑分析仪采集数据进行验证;结果表明该电路实现了I2C串行总线协议的要求。