A preliminary experience in the use of Chang’E-1 IIM data

The Interference Imaging Spectrometer (IIM) onboard the first lunar satellite of China, Chang’E-1, has acquired 84% of the area between south and north latitude 70°. To contribute to its usability, this paper presents our preliminary experience in the use of IIM data. Firstly, we provide one practicable method for the on-orbit correction of the inhomogeneity of sensor response. Secondly, aiming at the problem that the spectral range of IIM does not cover the absorption peak of the mafic mineral completely, we explore a method to approximate the absorption band center for IIM data. A strong correlation between the absorption band center and the wavelength at which the first derivative equals to 0 (i.e., stagnation point) was revealed. Based on the corrected data and the correlation, the absorption band center of several large craters was mapped. The distribution of rocks and minerals shown in the map of absorption band center for Aristarchus and Copernicus is in agreement with previous studies but with much finer structure. Horizontal and vertical lithologic diversity was detected in Zucchius crater. This paper demonstrates the potential of IIM data for the identification of lunar rocks due to its high spatial and spectral resolution. In a future study we will produce a global map of the absorption band center with greater accuracy and it is expected that this global map will provide complementary information for other hyperspectral data such as SP on KAGUYA or M³ on Chandrayaan-1.     

Two Lunar Mare Soil Simulants

Two new lunar mare soil simulants, NAO-2 and NAO-3, have been created in National Astronomical Observatories (NAO), Chinese Academy of Sciences. These two simulants were produced from low-titanium basalt and high-titanium basalt respectively. The chemical composition, mineralogy, particle size distribution, density, angle of internal friction, and cohesion of both simulants have been analyzed, indicating that some characteristics of NAO-2 and NAO-3 are similar to those of Apollo 14 and Apollo 11 landing site soils. NAO-2 and NAO-3 will be of great benefit to the scientific and engineering research on lunar soil.     

Kinetic Model of Gaseous Alkanes Formed from Coal in a Confined System and Its Application to Gas Filling History in Kuqa Depression, Tarim Basin, Northwest China

Based on the pyrolysis products for the Jurassic low-mature coal under programmed temperature,and chemical and carbon isotopic compositions of natural gas from the Kuqa Depression, the genetic origin of natural gas was determined,and then a gas filling model was established,in combination with the geological background of the Kuqa Depression.The active energy of CH_4,C_2H_6 and C_3H_8 was gotten after the data of pyrolysis gas products under different heating rates(2℃/h and 20℃/h)were fitted by the Gas O...     

基于高级生产者服务业视角的成渝地区城市网络体系

基于高级生产者服务业视角,建立了成渝地区17个最小分析单元(FUR,Functional Urban Region)×149家公司的量化矩阵,进行了基于服务值、连通性和网络性特征的分析,研究了成渝地区的城市网络体系结构及其特征.其中,FUR为重庆都市发达经济圈、渝西走廊地区和绝大部分地级市.结果表明:成都市和重庆都市发...     

中国西部城市绅士化现象及其形成机制——以成都市为例

绅士化是20世纪60年代产生的一种城市社会地理现象,对城市绅士化运动的实证研究是近年来我国人文地理学研究的热点之一,但很少以西部城市为案例进行研究.本文以成都为例,利用质性研究法(Qualitative Research)和深度访谈法探讨了西部城市的绅士化现象及其形成的内在机制.研究结果证实:成都市绅士化运动的产生主要是政府政策、制度创新、产业结构调整、开发商推动和居民个人意愿共同交织作用的结果,在绅士化运动的萌芽期、成熟期一直到最后完成一个周期,都是这几个因素共同作用的结果.成都市的绅士化运动除了在形式上表现出多样化外,在形成机制上也表现为复杂化,并且发现成都市的绅士化运动已与西方国家城市绅士化运动在现象和形成机制上具有相似性.     

中国城市经济网络结构空间特征及其复杂性分析

通过对当前城市体系研究进展和分析方法的阐述与总结,结合统计物理中复杂网络分析 工具,采用GIS、Matlab 和数据库等技术手段,构建城市联系网络,一定程度上突破了传统的等级 或位序城市关系研究,最后以2003 年和2007 年的Top1、Top5 和Top10 网络(城市联系强度的最大 值、前5、前10 名所连接的城市)为例证进行实证研究。研究表明：① 可将中国城市划分为北方城 市区、长江城市区、南部城市区３大城市区,形成了“三极多核”的空间格局。全国城市网络的联 系方向主要集中在环渤海地区、长三角地区和珠三角地区的主要城市(如北京、上海、广州)。但 是,从三大地区内部差异来看,环渤海地区城市等级性明显,长三角地区和珠三角地区呈现多核 化发展趋势,即城市网络化发展加强。Top10 网络反映各个城市前10 名的联系方向有所分散,即 呈现“最大联系极化、联系广度分散化”的发展趋势;② 从Top5、Top10 网络与随机网络、空间邻 近网络的对比来看,中国城市的实际网络既具有空间邻近网络这种规则网络的高聚类系数,又 具有随机网络所拥有的稀疏、长距离连接特性,表现为高聚类系数和短路径的双重特性,呈现 “小世界”网络特征;③ 从聚类系数的纵向变化看,2007 年比2003 年的城市网络连接更加分散, 区域的开放程度正在提高;④ 2007 年的平均路径长度稍有下降,说明全国城市网络中城市联系 更为紧密,连接通道增多。     

全无缝桥梁接线路面拉伸力学特性理论和实验研究

为了掌握和模拟全无缝桥梁接线路面弹塑性拉伸特性,本文基于钢筋和混凝土的单轴拉伸平均应力-应变本构模型,推导出接线路面的宏观弹塑性拉伸P-Δ理论模型;并对室内总长28 m的接线路面足尺模型,进行了拉伸试验。结果显示:(1)接线路面的理论与实验拉伸P-Δ骨架曲线在钢筋屈服前后都吻合得很好,可以直接用于全无缝桥梁抗震设计和损伤评估;(2)接线路面实验模型的拉伸变形量Δ高达14 cm时,仍未拉断,其延性甚好、有利于抗震。     

基于文化价值观的中国城市居民住房选择——以成都市为例

在城市快速转型与变迁过程中,中国城市居民的住房选择既受限于传统文化价值观长期根深蒂固的影响,又受到西方国家现代文化思潮的不断冲击,从而确立了随时代变迁的多样化的文化价值观体系。基于文化价值观视角,分析了中国城市居民的住房选择模式和机理,初步构建了计划经济体制下和转型期中国城市居民住房选择的理论模型。进而,以成都市为例,采用大规模面对面深度访谈式调查方法获取原始数据,揭示了文化价值观对中国居民住房选择的影响。研究表明:文化价值观一般会通过宏观和微观区位选择观、教育观、抚养和赡养观、婚姻观和养老观等四大途径单独或耦合影响城市居民住房的选择方式和结果,且随着后辈的成长和长辈年龄的增长,代际居住模式呈现出一种中国特有的家庭周期性分异规律。     

非洲城市二元社会空间结构模式

以城市中心变迁和阶层居住分化为研究视角,探究了非洲近代、现代2个时期的城市二元社会空间结构特征与模式。结果表明：不同时期,非洲城市内部的二元社会空间结构存在显著差异。随着欧洲殖民进程的结束,社会空间结构从旧二元向新二元转变。近代时期,非洲城市空间形态表现出典型的双城模式,殖民者与本地人的居住空间被严格区分;现代时期,非洲城市表现出新旧中心并存模式,中上阶层与贫民居住空间存在明显分异。政治、经济、人口与社会等因素是城市二元社会空间结构形成的重要驱动力。最后,为促进非洲城市社会空间的可持续发展提出了建议。     

Urban redevelopment,gentrification and gentrifiers in post-reform inland China: A case study of Chengdu,China

Since its process evolved in recent years, the definition of gentrification has expanded to cover different forms of social upgrading, new spaces and new actors around the world. Studies on gentrification in Chinese cities began to take off in the 2000 s. However, they all mainly focused on the newly emerging global cities and there has been a lack of investigation on provincial cities. Furthermore, discussions on gentrifiers′ profiles and their motivations for housing choice are absent from literature on Chinese gentrification. Therefore, this paper aims to assess the relevance of the broad definition of gentrification in provincial Chinese cities through empirical research on urban redevelopment projects in Chengdu, and to examine the characteristics of gentrifiers(as new incoming residents) in it. The results show the rationality of gentrification processes as urban redevelopment in Chengdu, and reveal original outcomes on the corresponding gentrifiers′ profiles and the motivations behind their housing choice, which are different from the general features of gentrifiers in standard Western gentrification research.