基于关键拓扑变动项辨识的调度操作潮流校核方法

为解决传统调度操作潮流校核中的有效性问题，定义了一种面向调度操作的关键拓扑变动概念，提出并实现了基于关键拓扑变动辨识的调度操作潮流校核方法。首先，剖析了调度操作安全校核的实施目的，围绕其运行断面潮流校验的校核目的，定义了面向调度操作的关键拓扑变动概念，并基于网络拓扑连接关系设计了其辨识方法。在此基础上，提出了基于关键拓扑变动项辨识的调度操作潮流校核方法，明确了其实施流程和要点。最后基于当前电网调度自动化系统实际，构建了其实施框架，并介绍了其在某电网的实施效益。     

煤田地震勘探中多井组合爆炸法浅析

地震勘探中炸药作为激发震源的激发条件多样,采用有效的震源激发方式,才能取得高信噪比的地震原始数据。本文依据有关爆破原理,理论结合实践经验,提出在厚黄土区采用多井组合的激发方式,能有效压制噪声,增强性噪比,提高数据质量。     

利用非糖物质快速鉴别单花蜂蜜

本文利用非糖物质快速鉴别四种常见的单花蜂蜜(枸杞蜂蜜、荆条蜂蜜、枣花蜂蜜和洋槐蜂蜜)。利用固相萃取除糖提取蜂蜜非糖物质,并用高效液相色谱(HPLC)结合化学计量学进行蜂蜜花源的判定。发现了四种单花蜂蜜的非糖特征标志物。芦丁、丁香酸甲酯、阿魏酸的含量在四种蜂蜜中差异最大。对羟基苯甲酸和脱落酸在枸杞蜂蜜中平均含量分别为0.59μg/g和0.42μg/g,可作为枸杞蜂蜜的花源标志物;对香豆酸和肉桂酸在荆条蜂蜜中平均含量为0.08μg/g和0.05μg/g,可作为荆条蜂蜜的潜在花源标志物;阿魏酸、异阿魏酸是枣花蜂蜜的特征标志物,平均含量分别为0.40μg/g和0.76μg/g;洋槐蜂蜜的特征标志物是芦丁和丁香酸甲酯,平均含量为0.08μg/g和0.14μg/g。利用高效液相色谱指纹图谱结合化学计量学方法(主成分分析和判别分析),四种单花蜂蜜依据其花源被成功区分。本研究对蜂蜜真实性判定有重要参考价值,为后续蜂蜜真伪鉴别奠定基础。     

Identification of digital technologies and digitalisation trends in the mining industry

Digitalisation in mining refers to the use of computerised or digital devices or systems and digitised data that are to reduce costs, improve business productivity, and transform mining practices. However, it remains increasingly difficult for mining companies to decide which digital technologies are most relevant to their needs and individual mines. This paper provides an overview of digital technologies currently relevant to mining companies as presented and discussed by mining journals, the media and insight reports of leading consultancy agencies. Relevant technologies were systematically identified using text-mining techniques, and network analyses established the relations between significant technologies. Results demonstrated that currently 107 different digital technologies are pursued in the mining sector. Also, an analysis of the actual implementation of digital technologies in 158 active surface and underground mines reveals a limited uptake of digital technologies in general and that the uptake increases with the run-of-mine production. Large-scale mining operations appear to select and apply digital technologies suitable to their needs, whereas operations with lower production rates do not implement the currently available digital technologies to the same extent. These minor producers may require other digital transformation solutions tailored to their capabilities and needs and applicable to their scale of operations.     

某能源公司安全管理效率评价

某能源股份有限公司是我国上市煤炭公司,为评价其安全管理效率,采用数据包络(DEA)分析方法,以员工人数、资产总额、安全生产费为投入指标,以原煤产量、百万吨煤死亡率为产出指标,对其2007—2018年间的安全管理效率进行了评价。结果显示,某能源公司在研究期间的安全管理效率较为低下,但近5年来有提升的趋势,2018年安全管理实现DEA有效;安全管理无效的主要原因为纯技术效率和规模效率低下。为提高安全管理效率,该企业应在安全投入资源的匹配性和安全投入规模的合理性两个方面采取针对性措施。     

Efficient model selection for real-time adaptive cold start strategy of a fuel cell system on vehicular applications

The PEMFC maximum power is greatly influenced by subfreezing temperature and degradation phenomena. Therefore, a dependable model is required to estimate the power with respect to the variation of the operating conditions and state of health. Semi-empirical models are potent tools in this regard. Nonetheless, there is not much information about their cold environment reliability. This paper comprehensively compares the performance of some models (already tested in normal ambient temperature) in subfreezing condition to introduce the most reliable one for PEMFC cold start-up application. Firstly, seven models are compared regarding voltage losses and precision. Subsequently, the three most dependable ones are selected and experimentally compared at sub-zero temperature in terms of polarization curve estimation for three PEMFCs with different degradation levels. The results of this study indicate that the model introduced by Amphlett et al. has a superior performance compared to other ones regarding the characteristic's estimation in below-zero temperature.     

灭火器的定位和有效性辨识研究

智慧消防是智慧城市建设的重要组成部分，在消防工作创新发展中发挥重要作用。灭火器作为扑救初期火灾的最普遍、最便捷和最广泛使用的灭火设施，在初期火灾的扑救和火灾防控中发挥重要的作用，其有效性和完好性是扑救初期火灾的必要条件。基于物联网及大数据的优势，建立消防灭火设施的定位与有效性辨识系统，并介绍系统的关键技术、网络架构、技术特征。此系统可对灭火器等消防灭火设施的伺应状态、完好性、有效性等功能特性进行跟踪巡检和辨识，以实现对灭火器的实时监控和智能化管理，促进消防设施建设的完善和优化，增强灭火系统的可靠性，充分发挥智慧消防技术在智慧城市建设中的优势。     

基于网络数据统计的食品欺诈研究分析

目的 建立符合我国国情的食品欺诈数据库, 补充国际上已建立的经济利益驱动型掺假(economically motivated adulteration, EMA)数据库空白。方法 搜集2001~2019年发生的食品欺诈行为, 初步建立具有中国国情的食品欺诈数据库。对数据库中信息完备的454条欺诈数据进行分析。结果 媒体报道数据占食品欺诈信息总数的71.6%; 食用农产品、酒类、乳制品、肉制品等11类产品是欺诈事件发生较多的食品类别; 产品欺诈(72.2%)高居食品欺诈类型的首位; 2001~2019年食品欺诈事件数量呈现出先上升后降低, 再上升再降低的“M”状趋势; 目前食品欺诈检测技术主要以理化分析技术为主, 针对的食品类别还有限; 食品欺诈信息以中国为主(89.0%), 涉及到世界各个地区。结论 食品欺诈是广泛存在的全球性问题, 本研究建立的食品欺诈数据库为预防食品安全风险起到了重要的技术支撑作用。     

A benchmark data set for two-phase Coriolis metering

For more than a decade there has been growing interest in the use of Coriolis mass flow metering applied to two-phase (gas/liquid) and multiphase (oil/water/gas) conditions. It is well-established that the mass flow and density measurements generated from multiphase flows are subject to large errors, and a variety of physical models and correction techniques have been proposed to explain and/or to compensate for these errors. One difficulty is the absence of a common basis for comparing correction techniques, because different flowtube designs and configurations, as well as liquid and gas properties, may result in quite different error curves. Furthermore, some researchers with interests in the modelling aspects of the field may not have suitable multiphase laboratory facilities to generate their own data sets. This paper offers a small data set that may be used by researchers as a benchmark i.e. a common data set for comparing correction techniques. The data set was collected at the UK National Flow Laboratory TUV-NEL, using air and a viscous oil, and provides experimental points over a wide flow range (8:1 turndown) and with Gas Volume Fraction (GVF) values up to 60%. As a first investigation using the benchmark data set, we consider how data sparsity (i.e. the flow rate and GVF spacing in the experimental grid) affects the accuracy of a correction model. A range of neural network models are evaluated, based on different subsets of the benchmark data set. The data set and some exemplary code are provided with the paper. Additional data sets are available on a web site created to support this initiative.