东营凹陷红层地球物理特征分析及有利储层预测

东营凹陷深部储层是干燥沉积环境下的一套红层,其中的孔一中储层厚度大、钻遇井少,具有较大勘探潜力。但目标区地层结构复杂,埋深从南到北逐渐变大,井震关系一致性不好,储层预测有很大难度。通过综合分析井震特征、优选地震属性、建立井震厚度关系,使用单一最佳属性法、多元线性回归法、基于学习型的非线性储层预测法,得出以下认识与结论：1）研究区红层具有薄互层典型特征,频率较上覆和下伏地层高,地震反射具有中振、低连、低信噪比特征;2）新研发的基于优势频率的流度因子具有最好的厚度相关性,最大振幅、均方根振幅、过零点数、能量半时也较好;3）无论是多元线性回归还是非线性支持向量机,优化的五属性储层预测效果要好于七属性;4）基于交叉验证的支持向量机方法十分适合深部储层小样本储层厚度预测,效果好于单一最佳属性法和多元线性回归法。     

Itinerant livelihoods: Street vending‐scapes and the politics of mobility in upland socialist Vietnam

This paper explores the politics of mobility for a group of rural inhabitants attempting to diversify their livelihoods in an especially prescribed environment, namely ethnic minority street vendors living and working in upland socialist Vietnam. These Hmong, Yao and Giáy individuals face a political environment where access and trade rights shift on a near‐daily basis because of the impulses of state officials, and where ethnicity is central to determining who gets to be mobile and how. We analyse three groups of itinerant vendors—those vending on the streets of an upland tourist town, the mobile minority wholesalers who supply them and other traders, and vendors who trek with Western tourists—to reveal the nature of this trade environment, while also highlighting the ways in which ethnic minority vendors negotiate, work around and contest vending restrictions in numerous innovative ways. We find that this focus on the micro‐geographies and everyday politics of mobility is essential to understanding how rural Global South livelihoods are fashioned and diversified, in this case revealing specific relationships and negotiations regarding resource access, ethnicity, state authority and livelihood strategies.     

交互作用视角下人口流动性与住房类型对城市入室盗窃空间格局的影响

已有研究发现社区住房类型对城市入室盗窃的空间格局有重要影响,但鲜有学者探讨位于不同人口流动程度社区环境中的不同住房对入室盗窃影响的差异。本研究以中国东南沿海城市ZG市为例,基于日常活动和社会失序等理论,以社区为分析单元,利用入室盗窃警情数据、第六次人口普查数据和兴趣点数据（Point of Interest, POI）,运用空间滞后负二项回归方法,分析人口流动性与住房类型的交互作用对入室盗窃空间格局的影响。结果表明：人口流动性高的社区入室盗窃率较高;自建住房比例对入室盗窃率有显著的正向影响,原公有住房比例和商品房比例则呈显著的抑制作用;交互变量的结果发现,人口流动性与不同类型住房变量的交互作用存在差异,其中,人口流动性与自建住房、经济适用房、原公有住房的交互变量对入室盗窃的发生具有显著的促进作用,而与商品房的交互对入室盗窃的影响并不显著。说明在探讨不同类型住房与入室盗窃的关系时,应重视其所在社区的人口流动程度的影响。     

创新型人才流动的空间结构与影响因素——基于高被引华人科学家履历分析

创新型人才作为重要的生产要素,对促进区域创新和竞争力提升具有决定性的作用。高被引科学家作为科研人员的杰出代表,是创新型人才的重要组成部分。本文以全球高被引华人科学家为研究对象,基于履历数据分析其流动,特别是工作阶段的流动特征;运用Heckman二阶段选择模型,对科学家工作阶段流动的影响因素进行分析,探究复合的人口迁移理论在高端人才流动中的适用性。研究发现：① 高被引华人科学家的人才流动轨迹表明,科学家的移动迁入地主要是国内外的核心城市（度中心性较高的城市）。② 高被引华人科学家工作阶段流动主要发生在中国和美国之间,中国城市多为人才迁入地,美国城市多为人才迁出地。③ 复合的人口迁移模型对高被引华人科学家工作阶段的区位选择解释作用明显。④ 高被引华人科学家国内外城市移动选择的影响因素不同,科学家的国内流动受到地理距离的限制,而迁入城市的拉力是高被引华人科学家产生跨国移动的主要原因。     

The historical logics and geographical patterns of rural-urban governance in China

Journal of Geographical Sciences - The advent of a mobile society has led to profound changes in China’s traditional rural-urban pattern and called for new strategies for urban and rural...     

IPCC AR6报告解读:强化技术和管理创新的交通运输部门减碳路径北大核心CSCD

IPCC第六次评估报告第三工作组报告交通运输章评估了该行业温室气体的减缓措施和转型路径。1990年以来,全球交通运输部门温室气体排放量一直增长,2019年已经成为全球第四大排放源,仅次于电力、工业以及农业、林业和其他土地利用(AFOLU)部门,其增长速度超过其他最终用途行业。报告强调了交通减排的重要性,主要的减排措施包括三方面:首先是减少需求,其次是对陆路交通部门进行脱碳,再次是对重型的水运和航空运输等进行脱碳。评估的多种燃料和动力技术处于不同的商业化水平,它们未来应用时间节点和规模各有不同。对于陆路交通来说,需要继续推进电气化;对于水运和航空来说需要进一步应用低碳技术,并优化国际管理机制;从中长期来看,所有部门都需要强调运输服务需求管理和运输效率的提升。情景相关的文献评述分析表明,全球温升目标要求全经济部门采取减排措施,特别是交通电气化的减排潜力在很大程度上取决于电力部门的脱碳。如果不采取减缓措施,交通运输部门排放在2050年可能增长65%(相对2010年);如果成功实施减缓战略,该部门的排放量将减少68%,这也与全球1.5℃温升目标要求相一致。关于这些减缓措施的分析和判断,对我国交通运输部门实现碳中和与碳达峰具有重要的参考意义。     

Unusual behavior detection and object ranking from movement trajectories in target regions

Unusual behavior detection has been of interest in video analysis, transportation systems, movement trajectories, and so on. In movement trajectories, only a few works identify unusual behavior of objects around pre-defined points of interest (POI), such as surveillance cameras, commercial buildings, etc., that may be interesting for several application domains, mainly for security. In this article, we define new types of unusual behaviors of moving objects in relation to POI, including surround, escape, and return. Based on these types of unusual behavior, we (i) present an algorithm to compute these behaviors, (ii) define a set of functions to weight the degree of unusual behavior of every moving object in the database, and (iii) rank the moving objects according to the degree of unusual behavior in relation to a set of POIs. We evaluate the proposed method with real trajectory data and show that the closest work does not detect the proposed behaviors and ranks objects considering only one type of unusual movement.     

Fractionation of Ni,Cr and Cu from Soil by Sequential Extraction Procedure and Determination by Inductively Coupled Plasma Optical Emission Spectrometry

Five‐step sequential extractions were employed to fractionation of Ni, Cr and Cu in soil polluted by anthropogenic activities and determine the mobility of the metals. Twelve samples were collected on an agricultural area that was located near an airport and intercity roads in Elazig‐Turkey. Exchangeable, organically bounded, carbonate bounded, adsorbed species on Fe and Mn oxides and residual species (except silicates) of Ni, Cr and Cu were extracted into solution by using CaCl₂, Na₄P₂O₇, Na₂EDTA, NH₂OH–HCl and HNO₃–H₂O₂, respectively. Mobile metal concentrations in fractions and total recoverable in soils were determined by using inductively coupled plasma‐optical emission spectrometry (ICP‐OES). Total recoverable Ni, Cr and Cu concentrations were in the range of 40–119, 45–126 and 23–72 mg kg^?1, respectively. It was observed that total concentrations of metals in some of the samples were higher than the permitted values. The sum of the mobile percentages of metals was found to be lower than 50%. The Ni, Cr and Cu percentages for exchangeable species are in the ranges of 0.18–1.64, 0.03–0.59 and 0.42–2.53%, respectively.     

Place ontologies and a new mobilities paradigm for understanding awareness of vulnerability to terrorism in American cities

There is increasing evidence that people interpret their risk from environmental hazards through places—such as urban neighborhoods. At the same time, heightened levels of mobility are theorized to be leading to a so-called “placeless society” and possibly nullifying theories of locality-based risk perception. The purpose of this study is to combine environmental risk-hazards scholarship with work in urban geography to explore the following question: is perception of vulnerability to terrorism influenced by place and mobility, and if it is, what is the relationship? Drawing on interviews with 93 householders in Boston, Massachusetts, I demonstrate that people perceive vulnerability via understanding the transportation environment as a place—not simply a conduit—and that these perceptions reflect larger societal structures, such as wealth and gender disparities, that combine with (im)mobility and human subjectivity to amplify or attenuate a person’s sense of vulnerability. These findings bring an understanding of subjective experience to the geography of transportation systems, which has not yet been theorized within the urban disaster literature.     

Job Proximity and Accessibility for Workers of Various Wage Groups

This research proposes two indexes, job proximity and accessibility, to measure workers' location advantage by residences with respect to their job markets. Job proximity is designed to capture the spatial separation between residents and jobs. Job accessibility measures one's ability to overcome such separation as may be affected by transportation means, road network, congestion, and intensity of competition for jobs among workers. The research compares the two measures among workers of various wage levels in an attempt to reveal who has the greatest advantage in job access and whether job access is a spatial or nonspatial issue. In Cleveland in 1990, the mean wage rate of 30,000 was a critical turning point: below this level, the higher the mean wage rate in a residential area, the farther the area was away from jobs; above this level, the trend is reversed. In other words, below a wage threshold, workers tend to trade better and more spacious housing (usually farther away from jobs) for more commuting; but above the threshold, workers retreat for saving in commuting (pertaining to their high opportunity cost of commuting). Although low-wage workers enjoy better job proximity, many of them (particularly some inner-city residents) have the worst job accessibility because of their limited transport mobility as indicated by a low level of automobile ownership. Job proximity declines with distance from the CBD and conforms to the monocentric model, as does job accessibility but to a less degree. Since workers with various wages respond differently to job access, the distribution of mean wage rates in the metropolitan area is hardly monocentric.