Calibration of local magnitude scale for Hindukush continental subduction zone

Hindukush is an active subduction zone where at least one earthquake occurs on daily basis. For seismic hazard studies, it is important to develop a local magnitude scale using the data of local seismic network. We have computed local magnitude scale for Hindukush earthquakes using data from local network belonging to Center for Earthquake Studies (CES) for a period of three years, i.e. 2015–2017. A total of 26,365 seismic records pertaining to 2,683 earthquakes with magnitude 2.0 and greater, was used with hypocentral distance less than 600 km. Magnitude scale developed by using this data comes to be M_L = logA + 0.929logr + 0.00298r – 1.84. The magnitude determined through formulated relation was compared with that of standard relation for Southern California and relation developed by the same authors for local network for Northern Punjab. It was observed that Hindukush region has high attenuation as compared to that of Southern California and Northern Punjab which implies that Hindukush is tectonically more disturbed as compared to the said regions, hence, seismically more active as well. We have calculated station correction factors for our network. Station correction factors do not show any pattern which probably owes to the geological and tectonic complexity of this structure. Standard deviation and variance of magnitude residuals for CES network determined using Hutton and Boore scale and scale developed in this study were compared, it showed that a variance reduction of 44.1% was achieved. Average of magnitude residuals for different distance ranges was almost zero which showed that our magnitude scale was stable for all distances up to 600 km. Newly developed magnitude scale will help in homogenization of earthquake catalog. It has been observed that b-value of CES catalog decreases when magnitude is calculated by using newly developed magnitude scale.     

建国50年来我国金红石矿产地质勘查及研究历史的回顾

我国金红石矿床地质勘查可分为 1949～ 196 6年、196 7～ 1976年、1977～ 1985年、1986～ 1999年四个阶段 ,实行金红石专门找矿的最后一个阶段发现矿床的速度远高于综合找矿的前三个阶段 ,共发现矿床 5 9处 ,探明储量 1亿t。相应的系统地质研究分为 1980～ 1989年初步研究、1990～ 1999年深入研究两个阶段。成矿理论体系初步形成 :矿床有 11个成因类型、5个成矿区带 ;矿床主要在变质岩地区沿深大断裂分布 ;成矿时代主要为晚元古代末期、泥盆纪、中生代及第四纪 ;成矿主要与板块的三次活动有关。     

Macrophyte‐driven transient storage and phosphorus uptake in a western Wisconsin stream

Investigations of phosphorus cycling and transport in streams lend insight into potential mechanisms of nutrient sequestration and can help mitigate human impacts. In this study, we examined the relationship between transient storage and phosphorus uptake in a cold‐water stream in western Wisconsin. Hydrological characteristics, nutrient spiralling metrics, macrophyte biomass, and geomorphological properties were quantified in 7 reaches of Spring Coulee Creek using injections of a conservative tracer alone or with added PO₄^3?. Fraction of median travel time due to transient storage (F_med²⁰⁰) was correlated with macrophyte biomass (r = .794, p = .033), and PO₄^3? uptake velocity was correlated with F_med²⁰⁰ (r = .756, p = .049). Stepwise linear regression was used to build models for transient storage and uptake velocity. Macrophyte biomass, stream bed slope, and riffle to pool ratio accounted for 99.6% of the variation in transient storage (p < .001). Transient storage, canopy cover, and slope accounted for 98.0% of the variation in uptake velocity (p = .002). This study shows that transient storage, primarily resulting from macrophyte beds, can be a significant factor regulating phosphorus uptake in stream ecosystems.     

个体与环境交互作用下中国成人超重肥胖情况变化趋势及影响因素研究

论文基于中国25个省份内635个社区的29586个成年居民2010—2016年的纵向追踪调查数据,分别利用非线性发展模型和多层Logistic回归模型,阐释中国居民超重肥胖情况的变化趋势,同时探究其在个体与环境交互作用下的影响机制。研究发现：① 以身体质量指数衡量的中国成人超重肥胖发生风险逐年增加,其中女性、年龄、有配偶人群、日均锻炼时长负向作用于成人身体质量指数增长速率;② 中国成人超重肥胖差异具有多层级性,个体层面社会经济属性、饮食习惯和行为方式,社区层面建成环境和自然环境,省域层面城市化水平,均能影响成人超重肥胖发生;③ 不同层级间超重肥胖影响因子具有交互作用关系,环境能通过影响个体心理状态及行为选择对个体健康结果的作用,间接作用于居民超重肥胖结果。研究结果旨在帮助中国成人居民达到更好的健康状态,以及为相关政府部门制定促进人口健康的政策提供理论依据。     

去中心化和（逆）全球化背景下中国人文地理学的批判性理论探索与方法创新

文章以去中心化和（逆）全球化为背景评估中国的人文地理学研究现状与未来去向。笔者认为近年贸易保护主义和中美争端的不断升级会减缓但不会扭转知识全球化的长期趋势。中国人文地理学者不应该对进入世界舞台失去信心,而应该勇敢正视当前理论和研究创新的重要机遇和挑战。文章通过对比中国人文地理学科与西方同行的研究,发现两者有不少共同的历史和传统,包括研究命题、研究框架和解释方式。比较而言,中国人文地理学更加规范统一、富有组织和系统性,并积极支持国家发展议程;而西方人文地理学强调个人自由、多样性、天马行空（“Blue-sky enquiry”）以及独立于政府的批判性视角。文章指出三种不同的价值观作为供中国人文地理学者进行理论批判的重要视角。其他可能的理论探索方式包括将问题置于不同的时间和空间,使用不同的数据和方法进行多重验证,从基本假设出发来进行理论解构,批判性地辨析因果关系,以及在不同的尺度下重新检视研究问题等。中国人文地理应通过更好地理解三种不同的地理知识,建立有利于激励研究创新的评估体系,探索国际研究和跨学科研究的前沿领域,促进比较研究,以及融合利用不同风格的研究方法等策略来促进研究创新。文章结尾提出三种可能的（逆）全球化情景供中国人文地理学者思考如何迈向充满新挑战和新机遇的未来。     

美国基础设施状况和重建计划

2018年2月发布的《美国重建基础设施立法纲要》是近年来美国在基础设施领域的重大改革之一,将对美国乃至世界基建投资、新技术普及、城乡发展产生深远影响。论文基于相关文献和资料,总结了美国基础设施落后的状况,从资金分配入手探讨了“重建计划”内在逻辑,并针对其可行性进行了分析,得出以下几点启示：有针对性、特定领域的基建投资仍是实现高质量发展的重要工具;地方政府与私营部门进入国家基建领域具有积极意义;基建计划的金融化、杠杆化不可避免,但需严防其过度;基建投资在短期上对低技术岗位有明显带动作用。     

超越“演化”:老工业区重构研究进展与范式反思

老工业区重构是经济地理学的重要研究议题。在全球化步伐放缓和全球制造业下行的宏观背景下,老工业区已愈来愈成为各国发展战略制定的核心对象。对近十年有关老工业区重构的中外文献进行细致梳理,指出了当下研究存在范式应用多元化的趋势,但这些范式在概念使用、尺度聚焦、时空侧重和机制解释上存在显著差异,缺乏相互融合和优势互补,面临现实应用瓶颈。特别是,长期用于解释老工业区重构的演化经济地理学,因其忽视多尺度-多主体-多分析单元的能动性作用而难以有效解释重构过程、机制、结果及其背后的地理性。本文将转型研究中的多层次视角同演化范式相结合,提供了一种具备上下因果辩证解释力的多尺度分析框架,能有效解释老工业区重构问题。在此基础上,探讨了未来研究方向。     

某港口工程地基处理中的强夯影响范围研究

强夯法是地基处理的一种常用方法,而确定强夯影响范围是强夯法应用的关键。结合某港口工程地基处理的实测资料,分析强夯振动在深度和广度上的影响范围,进而得出振动的位移、速度、加速度随距夯击点距离增大而逐渐衰减的曲线关系式。     

From modernization theory towards the ‘clash of civilizations’: directions and paradigm shifts in Samuel Huntington's analysis and prognosis of global development1

This paper critically discusses Samuel Huntington's contribution to development studies. Long before his currently debated work on the clash of civilizations, Huntington wrote on the political order in changing societies. In this highly influential book of the late 1960s he argued on the basis of modernization theory for strong governments to accompany the inevitable and universal process of modernization. His clash of civilizations seems to argue from different assumptions. It insists on the essential differences between cultures based on religion. These cultural differences would now give rise to the most important conflict constellations. In his earlier and later work Huntington insists on the primacy of Western values and the need to defend them. The author critiques the assumptions, concepts and some of the empirical evidence of Huntingtons recent study.