城市居民日常身体活动时空分异特征及影响因素

依托南京主城区居民日常身体活动调查数据,基于身体活动时空维度,挖掘城市居民日常身体活动时空分异特征,并采用混合效应模型探究身体活动分异的影响因素。研究表明：① 居民日常身体活动时空异质特征明显。工作日/非工作日不同类型身体活动时间安排及个体间差异均显著;工作性、交通性、家务性身体活动空间制约明显,而休闲性身体活动空间分布更具弹性;与工作日相比,非工作日不同类型身体活动空间范围变化收敛与扩散特征并存。② 活动空间范围、个人社会经济属性、自身健康状况对居民日常身体活动分异均具有显著影响。具体而言,居民日常活动空间范围决定身体活动的空间适应与选择;社会分工差异导致不同性别、年龄人群身体活动具有指向性;身体活动时间出现与个人社会经济实力倒置现象;而良好健康状态会激励居民日常身体活动的保持。     

经济地理学视角下创新网络与区域增长研究述评

创新是引领经济发展的第一动力，创新与区域增长之间的关系成为经济地理学者关注的重点领域。文章通过梳理近年来有关创新网络测度、创新网络与区域增长关系、创新网络作用于区域增长方式等方面的文献发现：网络资本可以弥补社会资本在解释企业创新结网经济价值方面的不足，区域增长呈现出网络化特征已成为学界共识，知识流与邻近性能较好地解释创新网络与区域增长的关系机理。然而，当前研究对社会资本如何促进区域增长，网络资本与区域增长关系模型如何构建，不同类型的邻近性与知识对区域增长的影响有何差异等问题尚不明确，建议重视网络资本对区域增长的作用并实证检验二者的关联，同时还应重视创新网络中企业家精神、创新个体心理行为特征等因素对区域增长的影响。     

2020年7月12日唐山MS5.1地震预警处理能力分析

2020年7月12日，河北唐山发生M_S5.1地震，河北省地震预警系统成功地处理并产出了这次地震预警各种结果数据，本文借助此次地震对河北地震预警网内震中距200km范围内台站产出质量以及地震预警前5次处理结果进行详细分析。此次地震发生在河北地震预警网内，平均台间距为10km，首台触发后3s、震后6s发布首次处理结果，与编目结果相比，震级偏差为-1.3，震中位置偏差为2.6km，盲区半径为18km。随着参与定位台站数量增多，震级与位置偏差越来越小，但震级仍整体偏小。河北地震预警网台站产出质量整体较高，其中烈度台作为地震预警最重要的组成部分，是决定预警效果的关键因素。本次地震震中距200km范围内，烈度台平均信噪比为48，震中距50km范围内平均信噪比为112，符合预警系统对信噪比的要求。本次地震预警结果表明，河北地震预警网内台站布局基本合理，波形质量较高，地震预警系统处理软件在本次地震中预警产出效果较好，已经具备了一定的地震预警能力。     

2020年云南省巧家县M_S 5.0地震强震动记录初步分析

2020年5月18日云南省巧家县发生M_S5.0地震,中国数字强震动台网的13个强震台站和昭通简易烈度计示范项目建设的43个烈度计台站,共接收168条强震动记录,经常规处理,绘制震区加速度峰值等值线图,并与云南地区常用地震动衰减关系进行对比,分析加速度峰值较大的几个台站频谱特性,计算地震动能量持时,讨论中小地震中高加速度峰值/低震害现象的成因,得到以下结论:(1) PGA等值线图形状较为平滑,其长轴呈NW—SE向展布;(2)云南地区常用地震动衰减关系预测值总体衰减趋势与观测值一致,但在近场(0—30 km)时,预测值基本偏小;(3)加速度峰值较大的几个台站记录主频集中在1—5 Hz;(4)小河镇台记录的能量持时较短,说明能量衰减较快,属脉冲型记录,不会对建筑物造成较大破坏。     

超慢速扩张环境下超镁铁质岩系统的热液硫化物成矿机理以及启示

西南印度洋63.5°E热液区是在超慢速扩张洋脊发现的首个超镁铁质岩热液系统。对取自该区的热液硫化物样品进行了系统的矿物学和地球化学分析，矿物学分析结果表明:该热液区硫化物为富Fe型高温硫化物，且经历了较深程度的氧化蚀变，大量中间态的Fe氧化物充填在硫化物矿物间的孔隙及内部解理中；这些硫化物相以白铁矿为主，其次是等轴古巴矿和少量铜蓝，缺乏黄铁矿、闪锌矿。据推断，该区的热液成矿作用分为4个阶段:低温白铁矿阶段→高温等轴古巴矿阶段→自形白铁矿阶段→后期海底风化阶段（少量铜蓝以及大量的Fe的羟氧化物）。与之相对应，地球化学分析结果表明这些硫化物的Fe含量较高（31.57%~44.59%），Cu含量次之（0.16%~7.24%），而Zn含量普遍较低（0.01%~0.11%）；微量元素较为富集Co（328×10-6~2 400×10-6）和Mn（48.5×10-6~1 730×10-6）。该区硫化物中较高含量的Fe、Co与超镁铁质岩热液系统相似，明显高于镁铁质岩热液系统。独特的热液硫化物矿物学特征和元素组成可能与该区普遍出露的地幔岩、橄榄岩蛇纹石化作用以及拆离断层的广泛发育的环境有关。     

Carbon pools and fluxes in the China Seas and adjacent oceans

The China Seas include the South China Sea, East China Sea, Yellow Sea, and Bohai Sea. Located off the Northwestern Pacific margin, covering 4700000 km~2 from tropical to northern temperate zones, and including a variety of continental margins/basins and depths, the China Seas provide typical cases for carbon budget studies. The South China Sea being a deep basin and part of the Western Pacific Warm Pool is characterized by oceanic features; the East China Sea with a wide continental shelf, enormous terrestrial discharges and open margins to the West Pacific, is featured by strong cross-shelf materials transport; the Yellow Sea is featured by the confluence of cold and warm waters; and the Bohai Sea is a shallow semiclosed gulf with strong impacts of human activities. Three large rivers, the Yangtze River, Yellow River, and Pearl River, flow into the East China Sea, the Bohai Sea, and the South China Sea, respectively. The Kuroshio Current at the outer margin of the Chinese continental shelf is one of the two major western boundary currents of the world oceans and its strength and position directly affect the regional climate of China. These characteristics make the China Seas a typical case of marginal seas to study carbon storage and fluxes. This paper systematically analyzes the literature data on the carbon pools and fluxes of the Bohai Sea,Yellow Sea, East China Sea, and South China Sea, including different interfaces(land-sea, sea-air, sediment-water, and marginal sea-open ocean) and different ecosystems(mangroves, wetland, seagrass beds, macroalgae mariculture, coral reefs, euphotic zones, and water column). Among the four seas, the Bohai Sea and South China Sea are acting as CO_2 sources, releasing about0.22 and 13.86–33.60 Tg C yr~(-1) into the atmosphere, respectively, whereas the Yellow Sea and East China Sea are acting as carbon sinks, absorbing about 1.15 and 6.92–23.30 Tg C yr~(-1) of atmospheric CO_2, respectively. Overall, if only the CO_2 exchange at the sea-air interface is considered, the Chinese marginal seas appear to be a source of atmospheric CO_2, with a net release of 6.01–9.33 Tg C yr~(-1), mainly from the inputs of rivers and adjacent oceans. The riverine dissolved inorganic carbon (DIC) input into the Bohai Sea and Yellow Sea, East China Sea, and South China Sea are 5.04, 14.60, and 40.14 Tg C yr~(-1),respectively. The DIC input from adjacent oceans is as high as 144.81 Tg C yr~(-1), significantly exceeding the carbon released from the seas to the atmosphere. In terms of output, the depositional fluxes of organic carbon in the Bohai Sea, Yellow Sea, East China Sea, and South China Sea are 2.00, 3.60, 7.40, and 5.92 Tg C yr~(-1), respectively. The fluxes of organic carbon from the East China Sea and South China Sea to the adjacent oceans are 15.25–36.70 and 43.93 Tg C yr~(-1), respectively. The annual carbon storage of mangroves, wetlands, and seagrass in Chinese coastal waters is 0.36–1.75 Tg C yr~(-1), with a dissolved organic carbon(DOC) output from seagrass beds of up to 0.59 Tg C yr~(-1). Removable organic carbon flux by Chinese macroalgae mariculture account for 0.68 Tg C yr~(-1) and the associated POC depositional and DOC releasing fluxes are 0.14 and 0.82 Tg C yr~(-1), respectively. Thus, in total, the annual output of organic carbon, which is mainly DOC, in the China Seas is 81.72–104.56 Tg C yr~(-1). The DOC efflux from the East China Sea to the adjacent oceans is 15.00–35.00 Tg C yr~(-1). The DOC efflux from the South China Sea is 31.39 Tg C yr~(-1). Although the marginal China Seas seem to be a source of atmospheric CO_2 based on the CO_2 flux at the sea-air interface, the combined effects of the riverine input in the area, oceanic input, depositional export,and microbial carbon pump(DOC conversion and output) indicate that the China Seas represent an important carbon storage area.     

PHoToNs–A parallel heterogeneous and threads oriented code for cosmological N-body simulation

We introduce a new code for cosmological simulations, PHo To Ns, which incorporates features for performing massive cosmological simulations on heterogeneous high performance computer(HPC) systems and threads oriented programming. PHo To Ns adopts a hybrid scheme to compute gravitational force, with the conventional Particle-Mesh(PM) algorithm to compute the long-range force,the Tree algorithm to compute the short range force and the direct summation Particle-Particle(PP) algorithm to compute gravity from very close particles. A self-similar space filling a Peano-Hilbert curve is used to decompose the computing domain. Threads programming is advantageously used to more flexibly manage the domain communication, PM calculation and synchronization, as well as Dual Tree Traversal on the CPU+MIC platform. PHo To Ns scales well and efficiency of the PP kernel achieves68.6% of peak performance on MIC and 74.4% on CPU platforms. We also test the accuracy of the code against the much used Gadget-2 in the community and found excellent agreement.     

Simultaneous interpolation and denoising based on a modified thresholding method

Studia Geophysica et Geodaetica - Seismic interpolation can provide complete data for some multichannel processing techniques such as time lapse imaging and wave equation migration. However, field...     

Variation behavior of pore-water pressure in warm frozen soil under load and its relation to deformation

Acta Geotechnica - Containing a considerable amount of unfrozen water, frozen soil may produce excess pore-water pressure under external load, especially at temperatures near the thawing point. The...     

准噶尔盆地西北部P-T转换期不整合的发育演化特征及意义*

二叠纪晚期—三叠纪早期是准噶尔盆地演化的重要转换期,发育了具有特色性的不整合面。本研究以该盆地的西北部为例,综合利用地震和钻井资料,探讨该时期不整合的发育演化特征及其地质意义。研究表明,转换期发育P₃/P₂期主要不整合与T₁/P₃期次要不整合,它们在研究区北部叠加复合,构成了三叠系底界叠合不整合面,在南部被上二叠统所分隔而独立存在;转换期经历了主要不整合的形成、主要不整合被上二叠统超覆、次要不整合与叠合不整合的形成及其被三叠系最终超覆4个演化阶段。不整合的发育演化特征揭示了晚海西期和早印支期构造运动对准噶尔盆地影响的强弱程度、地层记录的“楔形体”内涵以及上二叠统与下三叠统的层序归属。P-T转换期不整合面及其相邻地层形成了有效的油气运移通道、良好的储盖组合和类型众多的圈闭,因此具有重要的油气勘探意义。