Preliminary Feasibility Study on Application of Very Large Scale-Photovoltaic Power Generation in China

Solar energy photovoltaic power generation is hopeful to be applied in a large amount and possesses a certain proportion in the structure of energy in the future. In this paper, based on the forecasting of electric load demand and energy structure of power generation in the middle of 21 century, the pictures of VLS-PV power generation is composed, the operation characteristic of VLS-PV power generation and the adaptability of electric power grid for it is analyzed, the ways for transmitting large amount of PV power and the economic and technical bottlenecks for applying VLS-PV power generation are discussed. Finally, the steps and suggestions for developing VLS-PV power generation and its electric power system in China are proposed.     

视角和光照显著变化时的变化检测方法研究

探讨使用计算机视觉的最新方法来解决基于两幅高空间分辨率光学遥感图像的城市变化检测问题. 基本原理是通过提取聚类出现的变化直线段群来提取城市变化, 重点研究了拍摄视角和光照条件显著变化时的几个主要问题. 提出了一种基于多种类型图像特征的匹配方法来提取无变化建筑的顶部区域, 结合几何约束引入了变化盲区的概念以处理高层建筑在不同视角和光照下的图像不同现象. 使用真实遥感图像进行实验, 在视角和光照显著变化时仍可取得满意的变化检测结果.     

Fuzzy approach to select machining parameters in electrical discharge machining (EDM) and ultrasonic-assisted EDM processes

Condition monitoring of the machining process is very important in today's precision manufacturing, especially in the electrical discharge machining (EDM). This paper introduces a fuzzy-based algorithm for prediction of material removal rate (MRR), tool wear ratio (TWR), and surface roughness (R_z, R_k) in the EDM and ultrasonic-assisted EDM (US/EDM) processes. In this system, discharge current, pulse duration, and ultrasonic vibration of tool are the input variables and outputs are MRR, TWR, R_z, and R_k. The proposed fuzzy model in this study provides a more precise and easy selection of EDM and US/EDM input parameters, respectively for the required MRR, TWR, R_z, and R_k, which leads to better machining conditions and decreases the machining costs. The fuzzy modeling of EDM and US/EDM were able to predict the experimental results with accuracies more than 90%.     

超宽频带测向解模糊方法研究

针对实际测向系统中对工作频带及天线盘可利用体积等限制条件．对现有的三种典型测向解模糊方法进行了简单地说明，并提出了适于任意阵列的立体基线测向法。通过仿真分析比较了各种测向解模糊方法的性能及特点；并选取虚拟基线法和立体基线法在实际测向系统上进行了测试，测试验证了立体基线测向法在实际系统中的可行性。结合仿真结果可以看出立体基线测向法可灵活排列天线并实现超宽频带无模糊测向。     

质量隙透法测定三种偏苯三酸酯的极低蒸汽压

用质量隙透法测定了偏苯三酸 -三 -(2 -乙基己 )酯、偏苯三酸三异辛酯和偏苯三酸三异壬酯三种苯多酸酯增塑剂在 5 0～ 10 0℃内的蒸汽压数据 ,并回归出了三种物质的Antoine方程。测定装置以正十六烷和 1-十八烯作标准物质进行了校验 ,测定系统误差约为 5 %     

The Combined Effects of Oxygen Supply Strategy,Inoculum Size and Temperature Profile on Very‐High‐Gravity Beer Fermentation by Saccharomyces cerevisiae

The timing and concentration of oxygen supply to wort are of particular relevance in industrial beer brewing where tank volumes exceed brewhouse capacity, thereby necessitating fermenter filling in a multiple‐brew fashion. A simple technique for accurately controlling dissolved oxygen concentration is presented to model industrial, multi‐brew fermentations at bench and pilot scales. This method was employed to identify an effective oxygen supply strategy for batch fermentations conducted with very‐high‐gravity (VHG) wort. Addition of 25 ppm dissolved oxygen to the fermenting wort, 12 h after inoculation, was the most effective oxygenation strategy and reduced fermentation time by 33% compared to the control conditions. Pilot‐scale trials were subsequently conducted to further optimize VHG batch fermentation performance through simultaneous manipulation of key fermentation process parameters, including increased yeast inoculum size, early and increased free‐rise timing and temperature, and optimized oxygenation strategy. This approach reduced the time to achieve end of fermentation targets by 34% compared to trials conducted under control conditions. The improved fermentation profile was consistent over three successive inoculations and minimal impact was observed on key flavour volatiles. Employing the optimized process for VHG batch beer production would be industrially desirable due to the potential for improved process efficiency and cost‐savings.     

基于极低频输入下脉冲跟踪伺服控制方法研究

伺服控制系统在低速跟踪时 ,容易出现低速不平滑。文中提出了一种基于智能控制器的复合控制设计方法 ,仿真结果和实验结果证明了该方法具有优良的控制特性 ,满足极低频下伺服控制的要求。     

Flat-bed scanning as a tool for quantitative neuroimaging

The aim of this study was to compare three different imaging techniques which are used to provide data on the laminar structure of the human cerebral cortex. Region V1 of Brodmann's area 17 stained with cresyl violet was investigated, and a conventional semi-automatic morphometric evaluation, the videomicroscropic procedure and a new transparent flat-bed scanning technique were compared. The results of each digitizing method were converted into normalized profiles which allow the laminae in the striate cortex to be displayed. It was found that major laminar patterns can be detected by the scanning technique, but that subsidiary laminations are more clearly displayed by morphometry and videomicroscopy. For magnifications up to × 400 a high resolution transparent flat-bed scanner may be used in place of the videomicroscopy technique.     

ASIC Design of Floating-Point FFT Processor

An application specific integrated circuit (ASIC) design of a 1024 points floating-point fast Fourier transform(FFT) processor is presented. It can satisfy the requirement of high accuracy FFT result in related fields. Several novel design techniques for floating-point adder and multiplier are introduced in detail to enhance the speed of the system. At the same time, the power consumption is decreased. The hardware area is effectively reduced as an improved butterfly processor is developed. There is a substantial increase in the performance of the design since a pipelined architecture is adopted, and very large scale integrated (VLSI) is easy to realize due to the regularity. A result of validation using field programmable gate array (FPGA) is shown at the end. When the system clock is set to 50 MHz, 204.8 μs is needed to complete the operation of FFT computation.     

甚短距离光传输中保护和错误检测通道的实现

简要介绍了甚短距离VSR4-01.0光传输系统,通过实现保护通道和错误检测通道的功能,以确保光纤数据传输的正确性．采用Verilog HDL语言设计保护通道和错误检测通道,并进行了仿真．选用Altera公司的Mercury EP1M350F780C5 FPGA芯片进行了逻辑功能的仿真和验证。