基于腾讯位置数据的中国城市居民航空出行时空特征

随着中国经济社会的快速发展,航空出行成为居民出行方式的重要组成部分,并影响着城市格局。本文基于2019年4月28日—5月10日国内215个机场的腾讯定位请求数据,分析中国城市居民在工作日和五一假日两个场景下的航空出行时空特征,进而探究其与城市格局的关系。结果表明：①中国城市居民航空出行在空间上,总体呈现东部沿海高于内陆地区,且中部地区相对较低的特点;②在时间上,多集中在工作日,且京津冀、长三角、粤港澳大湾区、成渝等经济发达地区的中心城市更偏向“工作日优势型”,而中部地区及西南部地区的非区域中心城市更偏向“假日优势型”,并呈现以24小时为周期的下降、上升和波动的日变化,与工作日相比,五一假日提前2小时进入波动期,且居民假日航班时间选择更偏向在下午3点和晚上8点前后;③在工作日和假日两类场景下,所呈现的聚类等级分化与其所在城市规模之间关联性较强,在一定程度上接近城市金字塔的规模等级分布特征。     

区域经济发展差异研究进展与展望

区域经济发展差异研究一直是学者们关注的重点领域,且研究成果丰厚,主要集中在四个方面:区域经济发展差异的空间格局研究、时间演变研究、趋势预测研究和形成原因研究。但研究中还存在一些不足,针对问题,对区域经济发展差异研究提出了6个方面的展望:加强对欠发达区域经济发展差异研究、加强对边缘区经济发展差异研究、加强对城市及小尺度地域内部经济发展差异研究、加强对区域经济发展差异预测和预警研究、加强对区域经济发展差异动力机制研究、加强对区域经济发展差异对策研究。     

广州跨国机构的时空过程及其动力因素研究

在"思想全球化,行动地方化"的今天,跨国行为的迅猛发展导致众多跨国机构在城市的落户。随着跨国机构的不断发展且在国际社会发挥重要作用,相关研究逐渐引起关注。广州作为中国最重要的城市之一,外贸地位重要,国际化发展程度较高,但是跨国机构在城市的发展却极少受到关注。选取进驻广州的跨国机构为研究对象,通过分析跨国机构的类型及结构功能,研究其在广州的空间历程及其进驻因素。探讨广州跨国机构的时空分布过程及其内外影响因素的研究表明,伴随着广州城市空间重构和重心东移,跨国机构的时空特征表现为不断向城市东部分布和转移的过程:从历史时期在沙面的国际化经营,到改革之初在环市东的初步集聚,而2000年以后则表现为向天河北和珠江新城的分布和迁移。跨国机构进驻广州的原因,一方面源于广州区域中心功能、优越的地理和交通位置、发达的对外贸易的吸引;另一方面则体现了跨国机构发挥其地区总部管理和辐射功能的需要,并在此基础上地方和全球网络联系的建立。     

北宋时期疫灾地理研究

北宋时期(960-1127年)有记载的疫灾年份59个,疫灾频度为35.1%。其疫灾多发生于春、夏季节,秋、冬季节较少发生。整个北宋时期,疫灾频度呈周期性波动上升趋势,除960-969年上接五代疫灾周期和1120-1129年下接南宋疫灾周期外,其余时间可以划分出3个波长为50年的波动周期,第一波(970-1019年)疫灾频度为10%-40%;第二波(1020-1069年)疫灾频度为20%-60%;第三波(1070-1119年)疫灾频度为20%-70%。疫灾主要发生在黄河中下游、江淮之间及长江中下游地区,华南地区很少有疫灾流行,且疫灾都与战争有关。长江三角洲和开封地区为全国一级疫灾中心,成都、西安、洛阳、长沙为次一级疫灾中心。这些疫灾中心的形成,既与其人口密度相对较高有关,也与其人口流动性相对较高有关。     

An Examination of the Spatial–Temporal Isolation Model in a Nilotic Population: Variation across Space and Time in Nubians Using Cranial Discrete Traits

Nubian biological evolution has come under much scrutiny in preceding years with strong opinions dividing scholars' beliefs as to how it occurred. A new approach is necessary to elucidate subtleties of their population structure in order to shed light on the complex subject. This study employs a spatial–temporal model in an effort to test if in situ biological evolution was the mechanism for biological change. Biological distance was calculated from the phenotype using 20 cranial discrete traits observed in Nubian samples from the sites of Semna South, Kerma, and the islands of Hesa and Biga. The periods represented at Semna South are Meroitic, X‐Group and Christian, whereas the Kerma site yielded skeletal material from the Kerma period, and the islands of Hesa and Biga date to the Christian period. Mahalanobis D² with a tetrachoric matrix was used to calculate biological distances among the samples, and three‐way Mantel tests were applied to the distance, spatial and temporal matrices. Time was not significantly correlated with biological distance. However, an inverse relationship of time and biological distance is expected under the spatial–temporal model. A lack of significant geographic correlations, as found here, is unusual in most populations, but given the spatial construct of the sites along the Nile, this relationship is not completely unexpected. The lack of significant correlation among time, space and biological distance does not support the in situ hypothesis. Copyright © 2011 John Wiley & Sons, Ltd.     

Age Estimation by Tympanic Bone Development in Foetal and Infant Skeletons

This article analyses age‐related changes in the development of the temporal bone in a sample of foetal and infant skeletons to contribute to the estimation of age by means of this skeletal element in bioarchaeological and forensic contexts. The sample was selected from a contemporary documented skeletal collection and is constituted by the temporal bones of individuals of both sexes (n = 37) with ages from 23 weeks of gestation up to 11 postnatal months. Different states of fusion of the tympanic ring and development of the tympanic plate were scored separately, and intra‐observer consistency was evaluated. Both documented chronological age and skeletal estimated age were examined in relation to successive stages of fusion and development in the pre‐ and postnatal periods. It was found that the state of fusion of the tympanic ring is especially useful in the discrimination of foetal and postnatal individuals, whereas the development of the tympanic plate is helpful in the differentiation of individuals from and below 3 postnatal months. Even though a certain degree of overlap between successive stages was observed, the fusion of the tympanic ring and the development of the tympanic plate constitute good indicators of age in foetal and infant skeletons. Copyright © 2015 John Wiley & Sons, Ltd.     

DĒMOKRATIA'S POSSIBLE DISCONNECTION: UNTIMELY ANTIQUITY,TEMPORAL OUTSIDENESS,AND HISTORICAL FUTURES OF POLITICS*

This article discusses notions of possible disconnection in the post-1990s political present that are formulated as untimely articulations of the ancient Greek democratic past and of the concept of dēmokratia. These are modalities of transition that foreground political futurity as emanating neither from anticipation of evental change to come nor from abstract utopianism. Rather, dēmokratia’s projected break with the present and presentism is grounded in transtemporal confrontations and routes of historical memory. These are engagements with antiquity that take hold of and refigure the relation among past, present, and future politics, as well as the inside and outside of democracy, at a horizon of Nachleben (afterlife) that sustains no fixed beginning or end. I discuss these temporalities as disconnective in a sense that differs from historical futures opened up by technoscientific or anthropocenic prospects. Dēmokratia challenges the self-narration of present democracy as a project of the future by positing modalities of outsideness, repotentialization of the past, and interweaving of times and political languages in non-narrative terms. The outcome is a form of futurity that opens up the possibility of imagining not only a novel political subject and community but also a logic of their emergence that enables both to be incessantly reconfigured. Dēmokratia’s possible disconnection works against a sense of lost political futurity, but it needs to be recognized as grounded in a state of loss, insofar as political domination may also be built into future democratic principles. For this reason, it invites a reflexive problematic about the representability and translatability of disconnective political futures and communities.     

PHILOSOPHICAL REFLECTIONS ON THE WAYS OF MEMORY AND HISTORY

Philosopher Jeffrey Barash seeks to clarify the concept of collective memory, which has taken on wide‐ranging meanings in contemporary scholarship. Returning to the original insight of sociologist Maurice Halbwachs during the 1920s, he grounds the concept in the living social memory of the present, whose sphere is widened by its capacity to draw upon a past beyond its ken through the symbolization of its remembrance. He offers two preliminary propositions: first, there is a history to the way philosophers have contextualized collective memory through the ages; second, there is a politics in the transmission of collective memory, highly visible in the uses of memory by mass media in the contemporary age. He builds his argument around four interrelated interpretations concerning: the ever more circumscribed role attributed to collective memory in the passage from antiquity into modernity; the dependence of collective memory upon living memory; the rising power of media to mold collective memory to present purposes; and historical understanding vis‐à‐vis evocation of collective memory as oppositional ways of accessing the past. I close with commentary that places Barash's philosophical interpretation within the context of contemporary historiographical practice, with particular attention to the scholarship of French historian Pierre Nora on the French national memory, and that of German scholars Jan and Aleida Assmann on the preservation and transmission of memorable cultural legacies.     

Kinetics of Stone Degradation of the Castle of Chambord in France

A multidisciplinary approach combining scientific and historical data is developed in order to identify the environmental factors that cause degradation of stones and to attempt to date the onset of degradation and assess the time needed for its development. The method is applied to the Castle of Chambord, a prestigious monument in the Loire Valley in France. The genesis of the two main types of degradation (spalling and flaking) and the kinetics of their development are identified and analysed. The correlation between the different mappings and iconographic documents reveal that flaking develops on any type of fine limestone and can appear less than 60 years after the stone is placed on the castle for Richemont limestone, and less than 10 years for tuffeau. The other main type of degradation, spalling, is limited to tuffeau, but it is more difficult to quantify the kinetics of its development.