摘要：A planar InP-based Gunn diode with a notch doping structure is designed and fabricated for integration into millimeter-wave and terahertz integrated *** design two kinds of InP-based Gunn *** has a fixed diameter of cathode area,but has variable spacing between anode and cathode;the other has fixed spacing,but a varying *** threshold voltage and saturated current exhibit their strong dependences on the spacing（10 μm-20 μm） and diameter（40 μm-60 μm） of the InP Gunn *** threshold voltage is approximately 4.5 V and the saturated current is in a range of 293 mA-397 *** this work,the diameter of the diode and the space between anode and cathode are *** devices are fabricated using a wet etching technique and show excellent *** results strongly suggest that low-cost and reliable InP planar Gunn diodes can be used as single chip terahertz sources.

摘要：We designed and implemented a signal generator that can simulate the output of the NaI（Tl）/CsI（Na）detectors＇pre-amplifier onboard the Hard X-ray Modulation Telescope（HXMT）.Using the development of the FPGA（Field programmable Gate Array）with VHDL language and adding a random constituent,we have finally produced the double exponential random pulse signal *** statistical distribution of the signal amplitude is *** occurrence time intervals of the adjacent signals contain negative exponential distribution statistically.

摘要：A new kind （two end readout） of Multi-gap Resistive Plate Chamber with long readout-strip （LMRPC） is developed to be used at the large-area Muon Telescope Detector （MTD） at mid-rapidity at RHIC/STAR experiment for Time-of-Flight （TOF） measurement. The LMRPC has an active area of 87 cm× 17 cm, 10 gas gaps of 250 μm arranged in 2 stacks, with readout strips of 2.5 cm wide and 90 cm long. The considerations in LMRPC design related to its performance are discussed in this paper. The cosmic ray test results of a prototype LMRPC show a detection efficiency 〉95% and the time resolution -70 ps.

摘要：In communication networks （CNs）, the uncertainty is caused by the dynamic nature of the traffic demands. Therefore there is a need to incorporate the uncertainty into the network bandwidth capacity design. For this purpose, this paper developed a fuzzy methodology for network bandwidth design under demand uncertainty. This methodology is usually used for offiine traffic engineering optimization, which takes a centralized view of bandwidth design, resource utilization, and performance evaluation. In this proposed methodology, uncertain traffic demands are first handled into a fuzzy number via a fuzzification method. Then a fuzzy optimization model for the network bandwidth allocation problem is formulated with the consideration of the trade-off between resource utilization and network performance. Accordingly, the optimal network bandwidth capacity can be obtained by maximizing network revenue in CNs. Finally, an illustrative numerical example is presented for the purpose of verification.

摘要：A scheme to enhance near-infrared band absorption of a Si nanoparticle by placing the Si nanoparticle into a designed gold nanostructure is proposed. Three-dimensional （3D） finite-difference time-domain simulations are employed to calcu- late the absorption spectrum of the Si nanostructure and maximize it by generating alternate designs. The results show that in the near-infrared region over 700 nm, the absorption of a pure Si nanoparticle is very low, but when the same nanoparticle is placed within an optimally designed gold nanostructure, its absorption cross section can be enhanced by more than two orders of magnitude in the near-infrared band.

摘要：输出脉冲稳定性的需求对驱动自由电子激光产生的电子直线加速器装置束流稳定性提出了严格的要求,包括电子束平均能量、峰值流强、束团到达时间抖动和横向位置抖动等参数。基于正在建设的大连相干光源用户装置,探讨了最近提出的褶皱管用作能量稳定器的可行性。采用解析计算和数值模拟结合的方法,结合大连相干光源直线加速器的设计,在设计参数条件下能量稳定性至少提升10%。同时提供了褶皱管尾场设计的一般步骤。

摘要：The three-dimensional discontinuous deformation analysis(3D-DDA) is a promising numerical method for both static and dynamic analyses of rock systems. Lacking mature software, its popularity is far behind its ability. To address this problem, this paper presents a new software architecture from a software engineering viewpoint. Based on 3D-DDA characteristics, the implementation of the proposed architecture has the following merits. Firstly, the software architecture separates data, computing, visualization, and signal control into individual modules. Secondly, data storage and parallel access are fully considered for different conditions. Thirdly, an open computing framework is provided which supports most numerical computing methods; common tools for equation solving and parallel computing are provided for further development. Fourthly, efficient visualization functions are provided by integrating a variety of visualization algorithms. A user-friendly graphical user interface is designed to improve the user experience. Finally, through a set of examples, the software is verified against both analytical solutions and the original code by Dr. Shi Gen Hua.

摘要：In order to meet the application requirement of a certain long wavelength infrared （LWIR） seeker, a small volume, light weight and passively athermalized infrared OR） objective is designed in this paper. The two-lens telephoto struc- ture is adopted by merely using aluminum alloy as the housing material. By balancing the thermo-optical coefficient and thermal expansion coefficient of materials, an athermalized IR seeker with effective focal length of 90 mm and F number of 1.2 is achieved. The whole optical length is 75 ram, and the weight is only 234 g. The objective can remain fine imaging quality under temperature range from -40 ℃ to 60 ℃, which is beneficial to the lightweight design oflR seekers.

摘要：A concept-based approach is expected to resolve the word sense ambiguities in information retrieval and apply the semantic importance of the concepts, instead of the term frequency, to representing the contents of a document. Consequently, a formalized document framework is proposed. The document framework is used to express the meaning of a document with the concepts which are expressed by high semantic importance. The framework consists of two parts： the ＂domain＂ information and the ＂situation ＆ background＂ information of a document. A document-extracting algorithm and a two-stage smoothing method are also proposed. The quantification of the similarity between the query and the document framework depends on the smoothing method. The experiments on the TREC6 collection demonstrate the feasibility and effectiveness of the proposed approach in information retrieval tasks. The average recall level precision of the model using the proposed approach is about 10% higher than that of traditional ones.

摘要：Surface plasmonic polariton（SPP） waves with complicated wavefronts have important implications in nanophotonic sciences and applications. The surface electromagnetic wave holography method is applied to designed grooves on a metal surface for coupling a plane wave in free space to complicated wavefront SPP *** grooves illuminated by the plane wave incident from free space serve as secondary SPP waves sources, that radiate cylindrical SPP waves. New controllable wavefronts originate from these secondary SPP waves interfering with each other, based on the Huygens–Fresnel principle. Several applications of the method are demonstrated, such as converting coupling waves in free space into focusing SPP waves on a metal surface.