摘要：A high speed inductorless limiting amplifier （LA） in an optical communication receiver with the work- ing speed up to 20 Gb/s is presented. The LA includes an input matching network, a four-stage 3rd order amplifier core, an output buffer for the test and a DC offset cancellation （DCOC）. It uses the active interleaving feedback technique both to broaden the bandwidth and achieve the flatness response. Based on our careful analysis of the DCOC and stability, an error amplifier is added to the DCOC loop in order to keep the offset voltage reasonable. Fabricated in the 65 nm CMOS technology, the LA only occupies an area of 0.45 × 0.25 mm2 （without PAD）. The measurement results show that the LA achieves a differential voltage gain of 37 dB, and a 3-dB bandwidth of 16.5 GHz. Up to 26.5 GHz, the Sddlm and Sdd22 are less than -16 dB and -9 dB. The chip excluding buffer is supplied by 1.2 V VDD and draws a current of 50 mA.

摘要：We present a method to optimize the flat-band long-period fiber Bragg grating (FBG) in this *** method is based on the p^rticle swarm optimization method and the matrix transmission *** optimized refractive modulation profile does not introduce so many phase shifts and is easier to fabricate compared with that of layer-peeling method which introduces lots of π phase shift at each zero point of apodization profile in designing for the same problem.

摘要：An integrated implementation framework of an intelligent recommendation system for outdoor video advertising is proposed, which is based on the analysis of audiences＇ characteristics. Firstly, the images of the scene and the people who view the video advertisements are captured by the net- work camera deployed on the video advertising terminal side. Then audiences＇ characteristics can be obtained by applying computer vision technologies ： face detection, face tracking, gender recogni- tion and age estimation. Finally, an intelligent recommendation algorithm is designed to decide the most fitting video ads for each terminal according to multi-dimensional statistical information of its reover, a novel face detection method and a new face tracking method have been proposed to meet the practical requirements of the system, of which the average Fl-score is O. 988 and 0. 951 respec- tively.

摘要：Using Schiff base as a phase transfer catalyst, ethoxycarbonyl isothiocyanate was synthesized by reacting ethyl chloroformate with sodium thiocyanate. In order to get the best synthetic technology, an orthogonal test （L9（34）） was applied. The results show that reaction temperature, reaction time, content of catalyst and molar ratio of sodium thiocyanate to ethyl chloroformate are the main factors influencing the yield. The four factors chosen for the present investigation are based on the results of a single-factor test. The optimum synthetic technology is determined as follows： reaction temperature 35 ℃, reaction time 3 h, the content of catalyst （molar fraction based on ethyl chloroformate） 1.5% and molar ratio of sodium thiocyanate to ethyl chloroformate 1.1. Under the optimized synthetic technology, the experimental yield reaches 96.8%.

摘要：In this work, a bimetallic zeolitic imidazolate framework （ZIF） CoZn-ZIF was synthesized via a facile sol-vothermal approach and applied in lithiumion batteries. The as-prepared CoZn-ZIF shows a high reversible capacity of 605.8 mA b g-i at a current density of 100 mA g^-1, far beyond the performance of the corresponding monometallic Co-ZIF- 67 and Zn-ZIF-8. Ex-situ synchrotron soft X-ray absorption spectroscopy, X-ray diffraction, and electron paramagnetic resonance techniques were employed to explore the Li^storage mechanism. The superior performance of CoZn-ZIF over Co-ZIF-67 and Zn-ZIF-8 could be mainly attributed to lithiation and delithiation of nitrogen atoms, accompanied by the breakage and recoordination of metal nitrogen bond. Morever, a few metal nitrogen bonds without recoordination will lead to the amorphization of CoZn-ZIF and the formation of few nitrogen radicals.

摘要：We have provided optical simulations of the evanescently coupled waveguide photodiodes integrated with a 13- channels AWGs. The photodiode could exhibit high internal efficiency by appropriate choice of layers geometry and refrac- tive index. Aseamless joint structure has been designed and fabricated for integrating the output waveguides of AWGs with the evanescently coupled waveguide photodiode array. The highest simulation quantum efficiency could achieve 92% when the matching layer thickfiess of the PD is 120 nm and the insertion length is 2 μm. The fabricated PD with 320-nm-thick *** layer and 2-μm-length insertion matching layer present a responsivity of 0.87 A/W.

摘要：A 7.8-μm surface emitting second-order distributed feedback quantum cascade laser （DFB QCL） structure with metallized surface grating is studied. The modal property of this structure is described by utilizing coupled-mode theory where the coupling coefficients are derived from exact Floquet-Bloch solutions of infinite periodic structure. Based on this theory, the influence of waveguide structure and grating topography as well as device length on the laser performance is numerically investigated. The optimized surface emitting second-order DFB QCL structure design exhibits a high surface outcoupling efficiency of 22% and a low threshold gain of 10 cm-1. Using a π phase-shift in the centre of the grating, a high-quality single-lobe far-field radiation pattern is obtained.

摘要：In this study,a 3D virtual reality and visualization engine for rendering the ocean,named VV-Ocean,is designed for marine *** design goals of VV-Ocean aim at high fidelity simulation of ocean environment,visualization of massive and multidimensional marine data,and imitation of marine ***-Ocean is composed of five modules,*** management module,resources management module,scene management module,rendering process management module and interaction management *** are three core functions in VV-Ocean:reconstructing vivid virtual ocean scenes,visualizing real data dynamically in real time,imitating and simulating marine lives *** on VV-Ocean,we establish a sea-land integration platform which can reproduce drifting and diffusion processes of oil spilling from sea bottom to *** factors such as ocean current and wind field have been considered in this *** this platform oil spilling process can be abstracted as movements of abundant oil *** result shows that oil particles blend with water well and the platform meets the requirement for real-time and interactive ***-Ocean can be widely used in ocean applications such as demonstrating marine operations,facilitating maritime communications,developing ocean games,reducing marine hazards,forecasting the weather over oceans,serving marine tourism,and so ***,further technological improvements of VV-Ocean are discussed.

摘要：An equivalent corrugation pitch-modulated （ECPM） distributed feedback （DFB） semiconductor laser with two equivalently assisted phase shifts （EAPS） was theoretically studied and experimentally demonstrated. The simulated results showed that the longitudinal photon density distribution of the ECPM ＋ EAPS DFB lasers was much more uniform than that of a sole ECPM DFB laser without EAPS, and the longitudinal spatial hole burning was therefore suppressed more effectively. The results of experiment showed that good single longitudinal mode operation was achieved, with side mode suppression ratio （SMSR） being over 35 dB, and the wavelength range was from 1,559.64 to 1,563.02 nm when the operation current was from 50 to 160 mA at the temperature of 25 ℃, and the SMSR increased to 46.29 dB when the injection current was 130 mA.

摘要：A materials design tool for developing Pb-free soldering alloys in electronic package was developed based on comprehensive experimental data of phase equilibria and thermodynamic properties data accumulated with the CALPHAD (calculation of phase diagrams) method and contains 10 elements,namely,Ag,Au,Bi,Cu,In,Ni,Sb,Sn,Zn and *** can handle the calculation of phase diagrams in all combinations of these elements and all composition *** addition,based on this tool,the liquidus,solidus,phase fractions and constitutions,equilibrium and non-equilibrium solidification behavior,surface tension and viscosity of liquid,diffusion reactions and microstructural evolution,*** be *** examples of the calculation and application of this tool are *** design tool is expected to be a powerful tool for the development of Pb-free solders,as well as for promoting the understanding of the interfacial phenomena between Cu substrate and Pb-free solders in electronic packaging technology.