新冠疫情防控前后湖北恩施地震台背景噪声变化分析

利用2018年1月至2020年3月恩施地震台站观测的垂直分量连续波形数据,通过计算噪声功率谱密度和概率密度函数,统计其不同频段功率谱密度分布情况,对比分析疫情前后恩施地区噪声水平变化特征.同时,将2018年、2019年和2020年垂直向地震噪声的加速度幅值进行对比,发现春节前几日的加速度幅值变化曲线高度一致,表明这三年...     

19世纪中叶北京高分辨率沙尘天气记录：《翁心存日记》初步研究*

《翁心存日记》是迄今为止发现的记录天气现象最为详细的历史天气日记,保留了难得的19世纪中叶北京的沙尘天气记录。归纳了对历史文献记录中的沙尘天气进行分类的方法,通过《翁心存日记》,重建了19世纪中叶北京沙尘天气情况。分析发现当时北京年平均沙尘日多达31.36天,高于近60年来北京沙尘天气的平均水平。而19世纪中叶的北京沙尘天气中扬沙、浮尘和沙尘暴天气的构成和现代基本相似,年内分布特征也较相似。但19世纪中叶夏季沙尘比例较现代明显偏多46％,而冬季沙尘比例仅为现代比例的75％,这说明古今间沙尘天气的季节分布可能存在较大差异。另外,19世纪的沙尘天气同样存在明显的年际变化,且本地降水是影响年际变化的因素之一。     

BOOK REVIEWS

Book Reviewed in this article: Geographical Aspects of Health and Disease in India . Rais Akhtar and A.T.A. Learmonth , eds . Antarctic Treaty System: An Assessment . Proceedings of a Workshop at Beardmore South Field Camp, Antarctica. American Electoral Mosaics . J. Clark Archer and Fred M. Shelley . Kompas op Suidwes-Afrika/Namibie . W.S. Barnard , ed . Jerusalem in the 19th Century: The Old City . Yehoshua Ben -Arieh . The World as a Total System . Kenneth E. Boulding . A Social History of Housing 1815–1985, Second Ed . John Burnett . Human Migration . W.A.V. Clark . Regional Population Projection Models . Andrei Rogers . The State of Population Theory: Forward from Malthus . David Coleman and Roger Schofield , eds . Imagining Tomorrow: History, Technology and the American Future . Joseph C. Corn , ed. Swidden Agriculture in Indonesia: The Subsistence Strategies of the Kalimantan Kantú . Michael R. Dove . Glacial Geologic Processes . David Drewry . Physics of Desertification . Farouk El -Baz and M.H.A. Hassan , eds . Housing the Homeless . Jon Erickson and Charles Wilhelm , eds . Settlement Patterns in Missouri: A Study of Population Origins, with a Wall Map . Russel L. Gerlach . Desert Development: Man and Technology in Sparselands . Yehuda Gradus , ed . Nuclear Winter. The Evidence and Risks . Owen Greene , Ian Percival and Irene Ridge . The Take-off of Suburbia and the Crisis of the Central City . Günter Heinritz and Elisabeth Lichtenberger , eds . Regional Input-Output Analysis . Geoffrey J. D. Hewings . Spatial Transportation Modeling . Christian Werner . The Atlas of Georgia . Thomas W. Hodler and Howard A. Schretter , eds . Latin America. 5th ed . Preston E. James and C.W. Minkel . Applied Remote Sensing . C.P. Lo . Localities, Class, and Gender . The Lancaster Regionalism Group . Urban Social Movements: The City after Castells . Stuart Lowe . Politics and Method . Doreen Massey and Richard Meegan , eds . Land Use . A. S. Mather . The Kingdom of Coal . Donald L. Miller and Richard E. Sharpless . The Presidio and Militia on the Northern Frontier of New Spain, A Documentary History, Vol. 1: 1570–1700 . Thomas H. Naylor and Charles W. Polzer , S.J., comps . and eds . Nuclear Power: Siting and Safety . Stan Openshaw . The Central African Republic: The Continent's Hidden Heart . Thomas O'Toole . Environmental and Dynamic Geomorphology . Márton Pécsi , ed . Remote Sensing Principles and Interpretation . Floyd F. Sabins , Jr . Acid Rain and Friendly Neighbors: The Policy Dispute between Canada and the United States . Jurgen Schmandt and Hilliard Roderick , eds . Earth's Changing Surface: An Introduction to Geomorphology . M.J. Selby . International Migration: The Female Experience . Rita J. Simon and Caroline B. Brettell , eds . On Geography and Its History . D.R. Stoddart . Transportation Networks: A Quantitative Approach . D. Teodorovic . Processes in Physical Geography . R.D. Thompson , A.M. Mannion , C.W. Mitchell , M. Parry , J.R.G. Townshend . Imaging Radar for Resources Surveys . J.W. Trevett . Dominance and Affection: The Making of Pets . Yi -Fu Tuan . Capturing the Horizon. The Historical Geography of Transportation since the Transportation Revolution of the Sixteenth Century . James E. Vance , Jr . Nations at Risk: The Impact of the Computer Revolution . Edward Yourdon .     

《翁同龢日记》记录的19世纪后半叶北京的沙尘天气?

依据清代《翁同龢日记》中天气状况的描述，整理出公元1860～1898年间逐月的沙尘天气日数，基于记录完整月份的沙尘天气日数，统计分析了公元1860～1898年北京沙尘天气日数的平均状况和变化特征。分析发现公元1860～1898年，北京年均沙尘天气记录为10.4天，即使不考虑与现代观测记录标准的差别，亦肯定高于1990年代7.7天/年的平均频次；春季是沙尘天气的高发季节，其占全年沙尘日数的百分比达到70%，其中4月和5月两个月的接近53%；其次为冬季，占20%。与公元1961～2000年相比，公元1860～1898年的春季沙尘天气日数百分比偏高10.9%，沙尘天气在春季的集中程度明显偏高。公元1860～1898年间，年沙尘日数和春季沙尘日数均呈波动减少之势；研究时段内，共出现23次2天以上连续（或持续）的沙尘天气过程，最长的一次持续了4天。这些发现将有益于研究气候变化对沙尘天气影响和分析北京沙尘天气的演变规律。     

蓬莱19-3 油田事故溢油数值模拟

利用FVCOM(Finite-volume coastal ocean numerical model)数值模型和MM5风场预报模式,在对渤海海域水动力场进行数值模拟的基础上,基于"油粒子"的欧拉-拉格朗日跟踪法和随机走动原理,并考虑风对溢油油膜漂移扩散的直接作用,建立了海洋溢油油膜漂移轨迹和扩散的数值预测模型。利用建立的模型对2011年6月蓬莱19-3油田事故溢油进行了数值模拟,模拟结果与RADARSAT卫星遥感监测数据相吻合。研究结果表明:在渤海中部地区夏季事故溢油模拟预测中,风漂移因子取0.024最为合理,模型可用于渤海蓬莱19-3油田附近事故溢油轨迹和扩散的快速预报,从而为该区域的溢油事故应急响应提供科学依据。     

面向重大公共卫生事件的位置服务技术——以COVID-19疫情为例

2020年初暴发的新型冠状病毒肺炎(coronavirus disease 2019,COVID-19)疫情给全球人民生命安全和经济发展带来了严重影响。位置服务以庞大的地理空间信息数据库为依托,能向服务对象提供与地理信息相关的便捷、实时、精准的综合性服务,可很好地运用于紧急救灾、大流量人员追踪、复杂环境下的现场人员管控等事件中。事实证明,位置服务的优势特性在2020年春中国COVID-19疫情防控中起到了非常重要的作用。从北斗车联网平台、基于泛在定位的基础服务、时空大数据分析与疫情防控、智能导航机器人参与抗疫等多个方面阐述了中国COVID-19疫情下的位置服务应用。通过对这些应用及技术手段的分析总结,深化位置服务技术的内涵,可以为今后重大公共卫生事件的应急处置提供解决方案。     

牙鲆芳香化酶Cyp19a多克隆抗体制备及其应用

芳香化酶Cyp19a在鱼类性别决定和性别分化中起关键作用,通过调控体内雌、雄激素的转化来影响鱼类性别表型形成。为深入研究Cyp19a在牙鲆(Paralichthys olivaceus)性腺分化和发育过程中的表达规律及作用机制,本文从牙鲆cDNA中克隆获得1557bp的cyp19a基因编码序列,并成功构建了原核重组表达质粒。经体外重组与纯化获得较高纯度的重组Cyp19a蛋白;以此作为抗原免疫兔子,制备多克隆抗体。用间接酶联免疫吸附剂测定(ELISA)技术检测抗血清效价,评估其免疫原性。结果表明免疫结束后得到的抗体血清效价超过了1∶50000,且纯化后抗体具有较好活性。Western Blot(WB)检测结果表明Cyp19a兔多抗可以特异性识别牙鲆重组Cyp19a蛋白和内源性Cyp19a蛋白。蛋白水平的雌雄性腺差异表达分析显示,牙鲆Cyp19a蛋白在卵巢中高表达,在精巢中微量表达。利用Foxl2和Dmrt1重组蛋白处理牙鲆性腺分化期幼鱼可分别显著上调和下调Cyp19a的表达(P<0.05)。综上所述,本研究成功制备了牙鲆Cyp19a多克隆抗体并进行了应用,为深入研究牙鲆等鱼类性别分化机制提供有力工具。     

Letting failure be: COVID-19, PhD fieldwork and to not (want to) learn from failures

The ongoing COVID-19 pandemic has prompted researchers to rethink their fieldwork. My doctoral fieldwork plans, which involved conducting ethnographic research amongst Afghan refugees and migrants in New Delhi and Kolkata, were upended because of the recurring waves of the pandemic and the lockdowns/curfews that were imposed in their wake (2020−2022). Locked out of my field, my inability to conduct my research as planned amounted to a failure that could not be redeemed, especially because of time constraints. Using autoethnographic vignettes of my encounters in the lead up to the eventual suspension of in-situ fieldwork, I critically reflect on how I approached and felt towards failures in/of field and how these encounters speak back to the discourse on failure in academia. In doing so, this article advocates for the need to revisit failures simply for what they are, without necessarily demanding and/or (self) expecting that we recast them as stepping stones towards success. By challenging the neo-liberal desire to re-present failures in a productive light, I argue we can make greater room for more supportive discussions around failures without committing ourselves to the task of having to find triumph in (every) adversity.     

Understanding the mobility patterns of Mass Rapid Transit (MRT) passengers amid COVID-19 in Singapore using smart card data

The Mass Rapid Transit (MRT) is one of the major modes of public transportation in Singapore. Understanding the mobility patterns of MRT passengers has implications for improving transportation efficiency. As a city-state with a high population density, Singapore provides a representation of balanced urban dynamics that informs smart urban planning. In this paper, we investigated and visualized (using both static maps and dynamic web map applications) the spatiotemporal characteristics of Singapore's MRT commuting patterns before the COVID-19 pandemic (January 2020) and during the first outbreak (May 2020) and the Omicron wave of the pandemic (February 2022), using MRT smart card data. We also investigated the relationship between the passenger flows of individual MRT stations and the nearby land use types. Our results showed that the spatial patterns of Singapore's MRT commuters match the polycentric urban structure. In addition to central areas, several regional centres were identified as passenger hotspots in multiple time periods. Furthermore, during the outbreak of the pandemic, especially in the period of the ‘circuit breaker’, there was a major decline in MRT passenger flows and a decrease in average MRT commuting distances during weekend/holiday peak hours. Lastly, correlations between passenger flows of MRT stations and the proportion of nearby land use types have been identified.     

中国COVID-19疫情扩散的时空模式及影响因素

在2020年全球暴发新型冠状病毒肺炎（COVID-19）疫情的背景下,揭示中国疫情扩散时空模式及影响因素对于科学制定防疫策略具有重要作用。针对2020年1月24日—3月18日期间中国COVID-19疫情从快速扩散到逐步控制的完整过程,基于累计确诊病例数据,以317个地级市为对象,建立疫情扩散时空模式判别模型,结合峰位置、半峰间距、峰度、偏度等参数,解析时空模式的基本特征;基于交通可达性、城市关联程度和人口流动构建多元Logistic回归模型,揭示时空模式的关键影响因素。结果显示：① 距武汉市直线距离588 km为判别疫情扩散4种空间模式的有效边界,综合同一空间模式下的时间过程类别,得到13类疫情扩散时空模式。② 蛙跳型的疫情扩散相对严重;除近距离蛙跳型以外,其余空间模式的疫情扩散时间过程差异明显;各种时空模式的新增确诊病例峰值大多为2020年2月3日;所有普通类城市的平均半峰间距约为14 d,与COVID-19病毒的潜伏期一致。③ 与武汉市的人口关联度主要影响蔓延型和近距离蛙跳型空间模式,与武汉市的通航状况对远距离蛙跳型空间模式具有正向影响,迁出人口数量对蛙跳型空间模式有显著作用,综合型空间模式受初级和次级疫情暴发地的双重影响。不同城市应根据自身的疫情扩散时空模式,在疫情期间高度重视交通管控,从关键环节遏制疫情扩散。