晋冀蒙地区的垂直形变特征

基于1998、2006和2013年3期水准复测资料,平差计算得到1998~2006年和2006~2013年的垂直形变速率及其垂直形变速率梯度。根据计算结果研究晋冀蒙地区的地壳垂直形变运动趋势以及主要断裂带的活动性,分析区域垂直形变速率和垂直形变速率梯度的演变。结果揭示出吕梁山地块后一时段上升速率增加、太行山地块由前一时段上升变为后一时段下降、盆地地带变化复杂的垂直形变态势。     

土地集约利用数据库实时更新系统的研制

针对PDA产品信息采集不全、屏幕小不易图形编辑、维护保管难及数据库更新不及时等问题,文章将更新数据的编辑、审核和更新入库功能移至服务器端。在系统结构设计、数据库设计以及功能设计等基础上,利用组件式GIS开发、空间数据拓扑分析、软件系统集成、地理建模等先进技术,对土地集约利用数据库实时更新系统进行开发,实现了土地集约利用评价数据库采集和更新内外业一体化,进而实现与"土地集约利用终端系统"的完美对接,为土地集约利用评价系统提供了实时、准确的数据源。     

The non-linear redshift-space power spectrum of galaxies

We study the power spectrum of galaxies in redshift space, with third-order perturbation theory to include corrections that are absent in linear theory. We assume a local bias for the galaxies: i.e., the galaxy density is sampled from some local function of the underlying mass distribution. We find that the effect of the non-linear bias in real space is to introduce two new features: first, there is a contribution to the power which is constant with wavenumber, whose nature we reveal as essentially a shot-noise term. In principle this contribution can mask the primordial power spectrum, and could limit the accuracy with which the latter might be measured on very large scales. Secondly, the effect of second- and third-order bias is to modify the effective bias (defined as the square root of the ratio of galaxy power spectrum to matter power spectrum). The effective bias is almost scale-independent over a wide range of scales. These general conclusions also hold in redshift space. In addition, we have investigated the distortion of the power spectrum by peculiar velocities, which may be used to constrain the density of the Universe. We look at the quadrupole-to-monopole ratio, and find that higher order terms can mimic linear theory bias, but the bias implied is neither the linear bias, nor the effective bias referred to above. We test the theory with biased N -body simulations, and find excellent agreement in both real and redshift space, providing the local biasing is applied on a scale whose fractional rms density fluctuations are < 0.5.     

Two new large-separation gravitational lenses from SDSS

We present discovery images, together with follow-up imaging and spectroscopy, of two large-separation gravitational lenses found by our survey for wide arcs [the CAmbridge Sloan Survey Of Wide ARcs in the skY (CASSOWARY)]. The survey exploits the multicolour photometry of the Sloan Digital Sky Survey to find multiple blue components around red galaxies. CASSOWARY 2 (or 'the Cheshire Cat') is composed of two massive early-type galaxies at   z = 0.426  and 0.432, respectively, lensing two background sources, the first a star-forming galaxy at   z = 0.97  and the second a high -redshift galaxy  ( z > 1.4)  . There are at least three images of the former source and probably four or more of the latter, arranged in two giant arcs. The mass enclosed within the larger arc of radius ∼11 arcsec is  ∼33 × 10¹² M_⊙  . CASSOWARY 3 comprises an arc of three bright images of a   z = 0.725  source, lensed by a foreground elliptical at   z = 0.274  . The radius of the arc is ∼4 arcsec and the enclosed mass is  ∼2.5 × 10¹² M_⊙  . Together with earlier discoveries like the Cosmic Horseshoe and the 8 o'clock Arc, these new systems, with separations intermediate between the arcsecond-separation lenses of typical strong galaxy lensing and arcminute-separation cluster lenses, probe the very high end of the galaxy mass function.     

Relationship between flow speed variability of three tidewater glaciers and surface melt intensity in Greenland between 1979 and 2006

The margin of the Greenland ice sheet has undergone rapid changes over the past decade as a result of the thinning, acceleration, and retreat of many fast-flowing tidewater outlet glaciers. Satellite observations show that three major tidewater outlet glaciers in Greenland retreated between 2000 and 2005, with synchronous increases in flow speed, causing a deficit in ice sheet mass budget and the potential for sea level rise. In this study, we investigated whether this acceleration was related to surface melt processes, and found that both flow speed and positive degree day (PDD) anomalies of the three glaciers varied together, indicating a causal relationship. Jakobshavn Isbræ had lower flow speeds before 2000, during which PDD anomalies were negative, except for modest warming in 1993 and 1995. From 1999–2000, during which it is thought a threshold was passed, the flow speed of the glacier started to increase. However, the two glaciers in east Greenland showed a delayed response. Abrupt warming occurred in the vicinity of the two glaciers around 2001, but flow speed did not increase until 2003 for the Helheim Glacier, and until 2004 for the Kangerdlugssuaq Glacier. Furthermore, the two eastern glaciers switched to a deceleration mode more quickly than Jakobshavn Isbræ. The observed differences in both acceleration and deceleration among the glaciers suggest that the relationship between surface melt and outlet glacier dynamics is not simple but complex.     

中国乡村旅游重点村的空间特征与影响因素

乡村旅游重点村是推进乡村旅游高质量发展的典型示范,对优化乡村旅游供给、引领乡村旅游发展具有重要意义。本文运用最邻近指数、核密度估计等方法分析了中国1000个乡村旅游重点村的空间分布格局和结构特征,揭示了乡村旅游重点村的空间分异规律。运用多元线性回归、矢量缓冲分析、地理探测器等方法剖析了影响乡村旅游重点村空间分布的主要因素。研究发现：① 乡村旅游重点村总体呈“东多西少”的空间分布格局。省际空间密度分层特征明显,“双核心—环核群—带状区”的空间分布规律突出。② 乡村旅游重点村的空间分布具有显著的空间正相关性,地域间呈冷点分散、热点集中的空间分异格局。③ 6类乡村旅游重点村的核密度呈一高五低、分异鲜明的类型特征。④ 乡村旅游重点村空间分布格局的形成是自然生态、社会经济、交通配套、景区资源、政策环境五大因素共同影响的结果。人均GDP和居民消费支出具有显著正向影响,客源市场距离及交通通达距离是负向影响因素。⑤ 各类乡村旅游重点村空间分布的驱动因素各异,与村落资源禀赋和发展特点具有密切关系。     

江苏沿江地区的空间结构与区域发展

江苏沿江地区的空间结构是距上海市距离和到最近长江港口距离２个因素综合作用的结果,据此可由江苏沿江地区人均ＧＤＰ的分布状态而反推出上海市市区的人均ＧＤＰ值。近１０年来该地区的长江南侧形成了一条新的发展轴线,表明苏南的区域空间结构已 基本成型。就港口与区域的关系而言,该地区的长江南北两侧,均遵循港口与区域与互动的协调发展模式。这一发展规律的揭示,对轴线尚未成型的江北区域的发展,具有重要的指导意义。在此     

南极考察站废弃物对贼鸥食性的影响

对南极乔治王岛菲尔德斯半岛贼鸥的食性生态进行观测与研究 ,结果表明 ,本区贼鸥的食物结构中 ,自然生态类食物百分组成 ,棕贼鸥 (C .s.lonnbergi)占 63.4% ,灰贼鸥 (C .maccormic ki)占 77.8%。同期 ,取自考察站的人类废弃物中垃圾食物的百分组成分别为 36.6%和 2 2 .3%。贼鸥食性对考察站废弃物有一定的依赖性 ,与本区环境质量下降 ,尤其考察站对废弃物的疏于管理有着直接的关系。由此表明 ,强化南极考察人员环境意识 ,建立封闭式废弃物管理系统 ,对保护南极环境有重要意义     

中国城市网络的空间组织及其复杂性结构特征

全球化、信息化与快速城市化深刻影响了中国的城市体系,多区位企业组织所形成的城市网络正处于日益复杂的空间嬗变过程.基于2010年企业名录的总部—分支机构型关联数据,研究构建了330×330的地级以上城市网络连接关系,并运用复杂网络分析工具来探索中国城市网络的空间组织特征.研究发现:①中国的城市网络联系呈现以“北京—上海—广深—成都”为核心的菱形空间结构,不同等级的网络流强度具有显著的空间异质性,城市网络的空间组织是一个择优性和地理邻近性复杂作用的过程;②中国城市网络正处于一个简单随机向复杂有序结构的转化期,整体大尺度的网络结构还有待形成;③中国城市网络整体表现出明显的小世界网络效应;④中国城市的二值点度网络为明显的异配性连接特征,而加权强度网络连接则一定程度上表现出“富人圈”的现象;⑤中国城市网络的层级性并不明显,城市网络的点度和强度的关系呈非线性增加特征.     

我国省区间工业结构的异同与结构转换的调控途径

通过计算分析,本文认为我国省区之间工业部门结构既有趋同性,又存在趋异性;趋同性是基本合理的,而趋异性预示着各省区产业结构进一步调整的方向。我国省区工业结构差异主要发现在综合专业化能力、部门深层结构、结构质量三方面。以此为依据,本文提出了我国省区工业结构转换的调控途径。