数字化变电站与传统变电站间光纤纵差保护研究

在使用电子式互感器的数字化变电站和使用电磁式互感器的传统变电站之间,实现差动保护的关键是两侧电气量的同步。提出了解决该问题的具体方法：数字化变电站侧的保护装置实时跟踪间隔合并单元的采样频率,传统化站的保护装置实时跟踪数字化站侧的保护装置的采样频率,从而实现两侧电气量的同步。工程应用证明该方案完全可行。     

自动控制技术在德黑兰地铁通风系统中的应用

本文论述了德黑兰地铁工程通风系统的技术方案,对方案实施过程中遇到的具体问题进行了分析和研究,并详述了解决问题的技术细节。     

ACARS系统中MU组件的测试系统设计

为了在国内能够测试和维修多种型号的ACARS系统中的MU(管理组件)组件,并且不需要购买大量国外各种生产厂家的配套测试设备,通过采用通用的电子测试设备和工业控制计算机组成了MU组件的测试系统,这种设计增强了测试系统设计的灵活性和可靠性,降低了航空电子设备的维修成本和维修周期。应用表明,该系统能对MU组件进行自动测试和故障分析,大大方便航空公司的电子设备在国内的测试和维修。     

A green scheduling with adaptive spatial division multiple access grouping for multi‐user coordinated multi‐point networks

Multi‐User Coordinated Multi‐Point (MU‐CoMP), which couples CoMP with Multi User‐Multiple Input Multiple Output (MU‐MIMO), appears as a promising solution to enhance the Long Term Evolution‐Advanced (LTE‐A) system performance. However, some challenging issues in MU‐CoMP networks require more investigation. First, the set of users transmitting under CoMP mode should be properly identified. Secondly, time‐frequency resource should be efficiently partitioned between CoMP and non‐CoMP users in order to improve the system radio capacity. Thirdly, a fair and green scheduler is much needed for a more energy efficient system. This paper deals with these three issues. We propose an adaptive transmission mode selection according to the total load in the cluster and to users' quality of service. The adequate size of the Spatial Division Multiple Access users' groups is also analyzed. We finally propose a new scheduling algorithm to further enhance the radio capacity and the energy consumption in the cluster. Simulations results showed that significant improvements are obtained in terms of total system throughput and outage probability in the cluster with our proposed scheme. Moreover, energy efficiency has increased by four times with our proposed scheduling algorithm as compared to commonly used schedulers. Copyright © 2015 John Wiley & Sons, Ltd.     

A multi‐mode IFFT/FFT processor for IEEE 802.11ac: design and implementation

In this paper, we present 64/128/256/512‐point inverse fast Fourier transform (IFFT)/FFT processor for single‐user and multi‐user multiple‐input multiple‐output orthogonal frequency‐division multiplexing based IEEE 802.11ac wireless local area network transceiver. The multi‐mode processor is developed by an eight‐parallel mixed‐radix architecture to efficiently produce full reconfigurability for all multi‐user combinations. The proposed design not only supports the operation of IFFT/FFT for 1–8 different data streams operated by different users in case of downlink transmission, but also, it provides different throughput rates to meet IEEE 802.11ac requirements at the minimum possible clock frequency. Moreover, less power is needed in our design compared with traditional software approach. The design is carefully optimized to operate by the minimum wordlengths that fulfill the performance and complexity specifications. The processor is designed and implemented on Xilinx Vertix‐5 field programmable gate array technology. Although the maximum clock frequency is 377.84 MHz, the processor is clocked by the operating sampling rate to further reduce the power consumption. At the operation clock rate of 160 MHz, our proposed processor can calculate 512‐point FFT with up to eight independent data sequences within 3.2~μs meeting IEEE 802.11ac standard requirements. Copyright © 2015 John Wiley & Sons, Ltd.     

数字化变电站合并单元的应用和测试

基于IEC 61850-9-2的合并单元是数字化变电站过程层的核心设备。分析了合并单元的主要功能,介绍并比较了合并单元在国内外典型工程中的应用状况,并从配置文件测试、与保护测控设备接口测试、与电子式互感器接口测试和同步功能测试4个方面,深入研究了合并单元测试的内容和方案。     

Brave New Now

Under Tomorrow's Sky is a fictional future city. For the project, speculative architect Liam Young assembled a think-tank of scientists, technologists, futurists, illustrators and science-fiction authors to collectively develop this imaginary place, the landscapes that surround it and the stories it contains. The city forms a stage set for a collection of fictions, emerging infrastructures and design experiments. It is an imaginary landscape extrapolated from the wonders and possibilities of emerging biological and technological research. Here, speculative fiction provides a critical tool, which is visionary in its trajectory while provoking us to examine some of the most pertinent questions facing us today.     

MU90 HK反鱼雷鱼雷的作战效能

介绍了欧洲鱼雷公司对反鱼雷鱼雷作战效能的最新研究成果。在大量仿真的基础上,给出了不同方案的作战效能、关键设计参数,以及对战斗部装药量、速度、机动性和航程的需求,对不同技术方案进行了比较,并将其与软杀伤防御系统结合在一起进行了评估。经研究认为,在高性能轻型反潜鱼雷基础上开发 ATT 是最有前途的方法。     

A fast and simple LC-ESI-MS/MS method for detecting pyrrolizidine alkaloids in honey with full validation and measurement uncertainty

A fast and simple method was developed to determine pyrrolizidine alkaloids (PAs) in honey using liquid chromatography tandem mass spectrometry (LC- MS/MS) with electrospray ionization (ESI). An efficient extraction procedure was carried out by simply diluting with water, without the need of any additional clean-up steps. A full validation of the method was performed according to Commission Decision 2002/657/EC. The method was linear in the 050 μg kg⁻¹ range and presented satisfactory intra-day and inter-day precision with relative standard deviations of 1.45–10.2% and 1.60–1–0.2%, respectively. The measurement uncertainty, limit of detection (LOD) (0.1–1.0 μg kg⁻¹) and limit of quantification (LOQ) (0.2–1.5 μg kg⁻¹) were also calculated. The proposed method was applied to analyse eight PAs, namely, senecionine, senecionine-N-oxide, echimidine, intermedine, lycopsamine, retrorsine, monocrotaline and retrorsine-N-oxide, in 92 commercial honey samples from Brazil. At least three PAs were detected in 99.1% of the samples. PAs were not detectable (<LOD) in only one sample. Because PAs are natural toxins biosynthesized by plants, the importance of monitoring their concentration in honey is evident. For this purpose, a simple, low-cost extraction procedure was performed, and a high-throughput method was developed.