2016-12-25智利MW7.6地震震前电离层TEC异常探测

使用IGS发布的GIM数据,利用奇异谱(singular spectrum analysis, SSA)和四分位距法(inter quartile range, IQR)对2016-12-25智利MW7.6地震进行震前电离层异常探测。 研究表明,2种方法探测到的电离层主要异常特征基本一致,在震前4 d和震前7 d分别探测到明显的正异常和负异常,电离层异常自东向西移动,峰值点出现在震中附近,且震前4 d共轭区域出现明显的电离层正异常变化。相较于IQR探测,SSA探测突出了电离层主要的异常时间段和空间异常特征,但幅度和范围偏小,两者互为补充,可以探测出更加明显的地震电离层异常效应特征。由于距发震时间较短,在排除外界环境干扰因素后,认为此次电离层异常可能由智利地震引起。
     

智利MW8.8地震重力变化的GRACE观测与构造活动分析

利用GRACE重力卫星数据获取智利地区长期重力变化,提取特征点重力变化时间序列,分析2010 年智利MW8.8地震震前、同震及震后的重力变化,并将GRACE观测到的同震重力变化与球体位错理论模拟结果进行对比分析。结果表明,地震造成发震断层上、下盘显著的重力正负变化;特征点重力变化时序均清晰地揭示出地震造成的重力变化跃迁现象及震后3个强余震的异常信号,特别是震源域特征点重力在地震前2007~2010年呈现出“减小-增加-减小-增加-发震”的变化特征;GRACE观测到的同震重力变化与球体位错理论模拟结果在量级和分布形态上具有较好的一致性;地震不同阶段发震断层两盘重力变化亦有所差异,且受震后地层粘滞性效应影响,发震断层邻域重力变化呈持续性正负变化趋势。     

四川盆地中部中侏罗统沙溪庙组沉积期古环境与古气候演化——以永浅1井为例

四川盆地中部中侏罗统沙溪庙组沉积期古环境与古气候研究对揭示该时期盆内的沉积格局、重建古地理及油气形成与演化具有重要的理论和实践意义。本文以四川盆地中部永浅1井的47件泥岩样品为研究对象,通过主微量元素的变化特征恢复研究区沙溪庙组沉积期的古环境与古气候演化过程。研究结果表明,Sr/Ba比值、Rb/K2O比值、Ca/Mg比值和Ca/(Ca+Fe)比值指示川中地区中侏罗统沙溪庙组沉积期整体为淡水环境,但在沙溪庙组一段沉积中、晚期出现了短暂的水体盐度升高;V/(V+Ni)比值、U/Th值、V/Cr比值与Ni/Co比值指示沙溪庙组沉积期整体为间歇暴露的浅水氧化环境,局部为弱氧化或还原环境;C值、CIA值和Rb/Sr比值等指标显示,沙溪庙组沉积期古气候总体为温暖湿润的气候环境,但期间发生波动性干旱,在温暖湿润和半干旱—半湿润之间频繁波动。多元地球化学参数为川中地区中侏罗统沙溪庙组沉积期的古气候演化和区域性古气候对比提供了新的证据。     

中部地区人才的资源化开发及机制创新研究

从人才是第一资源概念出发,较详细的论述了人才资源属性及特征.在此基础上,分析了我国中部地区人才资源的现状及存在问题,认为加快人才资源化开发是实现中部地区崛起的关键,强化人才资源化过程中的机制创新则是实现中部地区人力资源大区和经济大区走向人才资源强区和经济强区的必须过程.最后对区域人才资源化的机制和体制创新进行了较为详尽的论证.     

中原城市群建设与河南旅游发展研究

中原城市群是河南省委省政府积极实施"中心城市和中心城镇带动战略的重要举措".城市群的发展必然促使交通系统更加完善,人均GDP增长更加迅速,招商引资更加强进,总体实力进一步增强,管理体制更加健全.从改善交通线路、扩大客源、提高旅游资源的互补开发等方面论述了中原城市群对河南旅游业发展的促进作用,同时提出了建立中原城市群综合旅游的初步设想.     

Imposex in Three Marine Gastropod Species in Chile and Potential Impact on Muriciculture

A survey of imposex was conducted between the Bay of San Vicente, Concepción, Chile (36° 50′) and the Bay of Renocavi, Puerto Montt, Chile (41° 35′), to determine if imposex is occurring in an area of collection and cultivation of the gastropod, Chorus giganteus. Imposex was recorded in three chilean muricids C. giganteus, Xanthochorus cassidiformis and Nucella crassilabrum complex. Percentage of imposex in females sampled ranged from 0% to 100%. The degree of expression of imposex was not so severe as to elicit sterility in the individuals surveyed. Incidence of imposex was as high as 47% in areas of harvest of C. giganteus for reproductive and cultivation studies for commercial production of this species. A six percent incidence of imposex was observed in Nucella proximal to the facility for cultivation of C. giganteus. Gastropods of the genus Nucella are used in other countries to monitor incidence of imposex and have demonstrated sensitivity toward tributyltin (TBT), the associated causal agent. Since sex of individuals in muriciculture is determined by the presence or absence of a penis, imposex may lead to erroneous classification of males and females. The incidence and severity of imposex in C. giganteus and related species may have a negative impact on sustainable cultivation and harvest of gastropods in Chile.     

Downtown office location dynamics and transformation of central Seoul, Korea

In recent years, central Seoul has been experiencing a dynamic transformation. In the process of reorganization of the urban industrial structure including tertiarization and quaternarization of the economic base of Seoul, business services are growing very rapidly and large scale urban renewal projects are quickly implemented. Downtown office activities become a nucleus for economic performance of Seoul and high-rise office buildings steer the landscape transformation of central Seoul. Even though there appears to exist some evidence that office districts have dispersed to several subcenters, major office activities are still concentrated in central Seoul. This paper redefines office industry in a narrow sense comprising only relevant economic sectors and office buildings as office activity-functioning units. It then explores the industrial networking and territorial specialization of office activities focusing on the dual process of concentration and dispersion in Seoul. The changing characteristics of the downtown linkages of office activities in this post-industrial era transforms the spatial economy of central Seoul into a more flexible and volatile system, while territorial concentration of power and control functions are fortified at the same time. Finally, the paper addresses the development of manufacturing- tertiary-quaternary industrial complexes, which can be regarded as emerging industrial clusters, producing the cultural economy of urban space and images for clients and customers, in relation to urban competitiveness and territorial specialization of large metropolitan areas. This revised version was published online in July 2006 with corrections to the Cover Date.     

The Inverse Problem for Collinear Central Configurations

We consider the problem: given a collinear configuration of n bodies, find the masses which make it central. We prove that for n ≤ 6, each configuration determines a one-parameter family of masses (after normalization of the total mass). The parameter is the center of mass when n is even and the square of the angular velocity of the corresponding circular periodic orbit when n is odd. The result is expected to be true for any n. This revised version was published online in July 2006 with corrections to the Cover Date.