高架索海上补给装置在小型船舶补给上的应用

针对现有高架索补给系统,在补给方式、波浪补偿装置、吊钩和接受端方面进行改进,提出适合小型船舶补给作业的补给系统;并在此基础之上对补给中关键参数进行计算,计算结果表明,此系统可以保证补给过程顺利实施,适合小型船舶补给需求。     

潮流发电水轮机基于动量定理的性能计算方法研究

以潮流发电水轮机的设计为研究背景,分析和总结了基于动量定理方法的四种流管模型(单盘面-单流管模型、双盘面-单流管模型、单盘面-多流管模型和双盘面-多流管模型)在竖轴变攻角水轮机的水动力性能计算中的应用,特别是能量利用率预报方面的应用。说明基于动量定理的模型在求竖轴变攻角潮流发电水轮机的水动力性能方面,能够预报一些定性特性和总体趋势,为水轮机的设计和计算提供一种初步方法。     

An Examination of ENSO''s Effect on the Monthly and Seasonal Climate of Hong Kong from a Statistical Perspective

This study aims to examine the effect of El Ni~no and La Ni~na on the monthly and seasonal climate of Hong Kong against the ENSO-neutral situation from a statistical perspective. Monthly and seasonal temperature and rainfall of Hong Kong and monthly number of tropical cyclones (TCs) coming within 500 km of the city over the 59-yr (1950-2008) period are examined under three ENSO situations, namely El Ni~no, La Ni~na, and ENSO-neutral. It is found that, compared with the ENSO-neutral situation, El Ni~no tends to be associated with wetter winter (December-February) and spring (March-May) while La Ni~na tends to be associated with cooler autumn (September-November) and winter. El Ni~no tends to be associated with a later start of the tropical cyclone season of Hong Kong while La Ni~na tends to be associated with more TCs coming within 500 km of Hong Kong in August-October. It is also found that, for April and June-December, although the monthly number of TCs coming within 500 km of Hong Kong during El Ni~no is generally lower than that under the ENSO-neutral situation, the difference is not statistically significant based on the current data sample size.     

The identification of an appropriate Minimum Inter‐event Time (MIT) based on multifractal characterization of rainfall data series

Different hydrological models of sediment entrainment, infiltration, overland flow production, soil loss, landslide occurrence, among others, need rainfall events data. The Minimum Inter‐event Time (MIT) used to separate rainfall events affects their properties. Therefore, it is highly important their correct definition. Various event definitions are commonly used in hydrology, and a high variety of MIT is applied. In this work, an easy method is proposed for deciding the proper MIT in a certain place when dealing with hourly rainfall data series. This new methodology is based on the scale invariance properties of rainfall, analysed with both multifractal and Self‐Organized Criticality theories. The similarity between some parameters from both analyses allows picking out the more appropriate MIT for the hourly rainfall data sets analysed, in Malaga (Southern Spain) and Bullileo (Central Chile). The method can be applied for different rainfall time resolutions according to the purpose of the model that needs the rain event information. Copyright © 2016 John Wiley & Sons, Ltd.     

蓝牙室内测距模型研究与精度分析

针对低功耗蓝牙进行室内定位过程中,蓝牙信号在室内传播过程中受到多路径、反射、非视距等误差的影响,导致蓝牙信号值存在波动性、奇异值等问题,进一步导致测距误差较大。为了验证环境对信号传播的影响,本文验证了3种主要影响因素对信号值的影响,并提出3种滤波方法对采集的初始值进行预处理;根据实际环境利用最小二乘法分段拟合测距模型;根据拟合的测距模型与处理后的RSSI值,得到准确的测距信息。实验表明,利用分段拟合的测距模型和混合滤波方法处理后的强度值,测距精度得到了明显的提高。     

航磁测量飞机飞行姿态影响及矫正

为消除航磁测量过程中由于飞机姿态变化而产生的感应磁场、涡流磁场等磁干扰,本文建立了干扰场模型,用补偿的方法对飞机飞行姿态产生的影响进行矫正。为验证方法的有效性,对M区实测航磁数据进行实时姿态矫正处理,结果显示,处理后的磁总场数据与国际标准地磁场基本吻合。证明本文提出的实时补偿方法能够消除飞机飞行姿态对磁测质量的影响。     

煤矿井下水平定向钻进技术与装备的新进展

煤矿井下定向钻进技术作为一项工程领域的新技术,已经广泛应用于煤矿井下瓦斯抽采、防治水、地质勘探和精确工程钻孔施工等领域。经过在国内30多个矿区推广应用,煤矿井下定向钻进技术和装备逐渐完善并取得新进展,形成了ZDY12000LD型大功率定向钻机、无线随钻测量系统、地质导向钻进装置及复合定向钻进工艺。结合现场试验完成了主孔深度1881 m的煤层定向长钻孔和1026 m岩层定向长钻孔,充分说明了ZDY12000LD型钻机功率大、钻进及事故处理能力强,无线随钻测量系统测量精度高,配套复合定向钻进技术形成的钻孔孔壁光滑、沉渣少、钻孔曲率小,钻进效率高。     

吉林松原地区地震前热红外亮温异常研究

使用小波变换和功率谱估计法,利用中国静止气象卫星亮温数据研究2017年以来松原地区3次M_S＞4.5地震前的热红外异常。结果表明, 2017-07-23 M_S4.9和2018-05-28 M_S5.7地震前的异常都是沿依兰-伊通断裂和密山-敦化断裂走向逐渐扩展的,即异常存在于松辽盆地的东部边缘,地震震中不在异常区内;2019-05-18 M_S5.1地震前异常不明显,可能是由于盆地内二氧化碳和甲烷等温室气体在前2次地震前后已得到最大量的释放。     

内蒙古山洞台站背景噪声特征分析

计算内蒙古测震台网2019-12~2020-11山洞观测数据的加速度功率谱密度（PSD）和相应的概率密度函数(PDF),研究相应台站的背景噪声特征。结果表明,高频段背景噪声的昼夜差异显著,疫情防控期间噪声水平明显低于其他时段;次级微震频段背景噪声季节性变化显著,噪声水平冬季强、夏季弱,随着台站离海岸线距离增大,PSD峰值有逐渐减小的趋势;主微震频段背景噪声在10~20 s均有峰值,峰值冬季最强,春、夏、秋季基本没有差异,不同台站同一季节峰值差异小;长周期段噪声水平四季差异不大,春、夏季略高于秋、冬季。     

基于高分卫星影像的复杂山区光伏电站信息提取

该文基于高分卫星资料,通过基于规则的面向对象分类、基于最邻近法的监督分类及基于CART分类器的监督分类三种不同分类方法,对复杂山区光伏电站进行提取,对比三种分类提取方法结果并完成精度验证。结果表明,合理的分割参数有利于提高光伏电站提取精度;基于规则的面向对象分类法光伏电站提取精度最佳,最邻近分类法次之,CART分类器分类法最差,可利用基于规则的面向对象分类法较为准确地进行复杂山区光伏电站信息提取,为光伏产业健康、合理发展提供一定的数据支撑。