资本积累驱动下不同尺度地理空间的不平衡发展——史密斯马克思主义空间理论探讨

尼尔·史密斯是世界知名的人文地理学者和马克思主义地理学家。他在不平衡发展理论的基础上,整合马克思主义和地理学的资本周期运动、空间一体化与尺度推移等范畴,提出了实现平衡发展的途径,极大地丰富和发展了马克思主义地理学,为研究当代社会空间问题提供了更为具体的分析框架和新的理论解释。其理论的核心是把地理空间视为生产资料、社会产物以及空间关系的总和,认为地理空间生产是特定时期资本增殖的重要方式。目前中国学者虽引进其部分理论,但整体了解还比较欠缺。本文将其理论概括和梳理为空间生产、地理尺度、美式帝国主义、绅士化4个方面,分析资本积累驱动下地理空间的不平衡发展过程,深度解析社会、空间与地理的尺度交错与互动关系,阐明资本周期运动、美式帝国扩张和绅士化的逻辑关联,最后以租隙理论为主剖析了城市尺度的资本周期运动。本文旨在为国内学者研究史密斯的马克思主义空间理论以及马克思主义地理学提供纲要和逻辑线索,并为中国城市化转型和经济增长方式转变提供理论参考和方法启示。     

西部山区县级土地利用制图的尺度选择——以四川省甘孜州为例

针对西部山区县级土地利用总体规划修编工作中暴露出的制图尺度问题,以四川省甘孜州为例,在土地利用制图成果的基础上分析了该区内石渠、甘孜、乡城不同尺度的县级土地利用制图效果。通过对比,探讨了西部山区土地利用制图适宜尺度的选择。结果表明：（1）不同尺度下县级土地利用制图在保持精度前提下,更注重经费和人力投入来合理选择尺度。（2）西部山区土地详细规划制图宜采用大比例尺（1∶5万或更大）;县级重点城镇的土地详细规划,以1∶500或1∶1 000为主。土地利用总体规划制图,州级重点县可以考虑1∶1万-1∶5万尺度,重点城镇采用1∶1 000和1∶500;一般县宜采用1∶5万-1∶10万的尺度;而其他如位于高寒牧区的县可以采取1∶10万-1∶25万的数据。     

Effect of hysteretic smoothness on inelastic response spectra with constant‐ductility

This paper presents an efficient methodology for computing constant‐ductility inelastic response spectra. The computation of constant‐ductility spectra involves numerical root‐finding algorithms to find the strongest structure providing a desired ductility response. Smooth inelastic structural behavior is modeled using a first‐order nonlinear differential equation and the transient structural response is solved using an implicit algorithm requiring Newton iterations at each time step. For structural models with smooth hysteretic behavior (not piece‐wise linear), a simple root‐finding method involving a combination of hyperbolic fits, linear interpolation, and Newton's method converges upon the highest strength (conservative) solution with a small number of iterations. The effect of the hysteretic smoothness on the occurrence of multiple roots is examined for two near‐fault and two far‐fault earthquake records, and for two measures of ductility and for normalized hysteretic energy. The results indicate how the smoothness of the hysteretic behavior affects ductility demand and constant‐ductility response spectra. Copyright © 2010 John Wiley & Sons, Ltd.     

北京市人口密度空间分布及其尺度特性研究

利用北京市第六次人口普查数据,在对人口统计数据进行空间化处理的基础上,分析了城市人口密度分布的统计特征及其空间自相关性,充分证明了北京市人口密度分布具有非常强烈的空间自相关性,并已经凸显出城市人口密度多核心分布模型的特征;在对人口统计数据进行格网化处理的基础上,分析了6种不同尺度下北京市人口密度空间分布的统计学特性和空间自相关性,证明了北京市人口密度的空间分布具有尺度特性;本文进一步对尺度特性影响下的人口密度空间分布特性空间自相关性进行了对比研究,从而揭示出空间自相关性与尺度变化间的规律。     

粤港澳区域联动发展的关键科学问题与重点议题

在新时期新背景下,实现粤港澳区域联动发展具有紧迫性、必要性和重大现实意义。本文认为研究粤港澳区域联动发展需要以区域一体化理论体系、“全球—地方”尺度理论、区域空间相互作用理论体系为主要的理论基础。其关键科学问题是研究“一国两制”下粤港澳尺度的区域联动理论,探索粤港澳区域联动的机制、关键因素、模式与路径;提出了粤港澳区域联动发展关注的4个重点议题：①粤港澳区域一体化/协同理论的研究与探索;②粤港澳地位与作用研究;③粤港澳联动的多尺度、多主体影响机制与模式研究;④粤港澳联动发展的实施路径研究。     

X‐shooting Herbig Ae/Be stars: Accretion probed by near‐infrared He I emission

The Herbig Ae/Be stars are intermediate mass pre‐main sequence stars that bridge the gap between the low mass T Tauri stars and the Massive Young Stellar Objects. In this mass range, the acting star forming mechanism switches from magnetically controlled accretion to an as yet unknown mechanism, but which is likely to be direct disk accretion onto the star. We observed a large sample of Herbig Ae/Be stars with X‐shooter to address this issue from a multi‐wavelength perspective. It is the largest such study to date, not only because of the number of objects involved, but also because of the large wavelength coverage from the blue to the near‐infrared. This allows many accretion diagnostics to be studied simultaneously. By correlating the various properties with mass, temperature and age, we aim to determine where and whether the magnetically controlled mass accretion mechanism halts and the proposed direct disk accretion takes over. Here, we will give an overview of the background, present some observations and discuss our initial results. We will introduce a new accretion diagnostic for the research of Herbig Ae/Be stars, the HeI 1.083 μm line (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

结合ASIFT和归一化的抗仿射变换遥感影像盲水印算法

针对遥感影像使用过程中,含水印影像经过仿射变换后水印与影像的同步性被破坏,导致水印无法正常检测的问题,本文提出了一种适用于遥感影像的抗仿射变换盲水印算法。首先通过ASIFT算法提取影像具有仿射不变性的特征点,根据特征尺度的大小与特征点间的欧式距离筛选适量特征点,构造对应的正方形特征区域;然后通过计算特征区域的仿射不变矩得出归一化变换函数的参数,对特征区域进行归一化处理,并以归一化特征区域的不变质心为中心提取子区域作为水印嵌入区域,对该区域进行二级离散小波变换,得到水印嵌入区域的低频信息;运用量化嵌入规则将水印嵌入到低频信息中,依次进行低频信息逆小波变换,水印嵌入前后特征区域差值图像反归一化,最后将反归一化差值图像叠加在原始影像特征区域上,完成水印的嵌入。实验选用了3000像素×3000像素的高分二号遥感影像作为载体影像,含版权信息的二值图像作为水印,实验表明：含水印的遥感影像经过旋转、平移、缩放在内的仿射变换后,仍能准确提取水印信息;算法可有效抵抗加噪、滤波、裁剪等常规水印攻击,攻击后影像提取的水印与原水印相关系数均高于0.9;水印具有良好不可感知性;在水印提取时无需原始遥感影像,属于盲水印算法。     

Modelling the runoff-sediment yield relationship using a proportional function in hilly areas of the Loess Plateau, North China

Based on data observed at the 12 small watersheds in hilly areas of the Loess Plateau, North China, the relationship between event runoff volume and sediment yield is examined. The results reveal that the runoff-sediment yield relationship at the inter-event timescale is mainly determined by the runoff-sediment concentration relationship at the intra-event timescale. In the study area, the sediment concentration tends to be stable when the flow discharge exceeds a certain critical value. Many factors that are important for determining the characteristics of low-magnitude events, such as flow discharge, particle size of fluvial sediment, and accumulation of loose material on land surfaces prior to a rainstorm, appear to have little importance for high-magnitude events. Consequently, mean sediment concentration tends to be stable for large flood events, suggesting a strong similarity between the two flow-sediment relationships at inter-and intra-event temporal scales. Furthermore, a proportional function is proposed to predict event sediment yield, and the correspondence between the predicted and observed sediment yields is examined. The performance of the model is good for high-magnitude events, especially extreme events. The applicability of the proposed model at the annual timescale is also discussed.     

欠发达农区外出务工规模及影响因素分析

根据对河南省农区十村11251 户农户的入户调查资料,认为农民外出务工的数量与规模是经济因素、家庭 因素和环境因素综合作用的结果。多元回归模型显示：①外出务工经济收益与成本、家庭人口状况、农户家庭经营 地、农户家庭生活性支出等正向影响农户外出务工的规模;②农区家庭劳动力文化状况中,初中及以下学历人数正 向影响农区外出务工的规模,高中及以上学历人数负向影响农区外出务工的规模;③环境因素中,经济水平因子对 农区外出务工规模的影响是正向的,地形、通达性和土地类型等三个因子对农区外出务工规模的影响是负向的。     

Evaluation of an empirical orthogonal function–based method to downscale soil moisture patterns based on topographical attributes

Soil moisture influences many hydrologic applications including agriculture, land management and flood prediction. Most remote‐sensing methods that estimate soil moisture produce coarse resolution patterns, so methods are required to downscale such patterns to the resolutions required by these applications (e.g. 10‐ to 30‐m grid cells). At such resolutions, topography is known to affect soil moisture patterns. Although methods have been proposed to downscale soil moisture based on topography, they usually require the availability of past high‐resolution soil moisture patterns from the application region. The objective of this article is to determine whether a single topographic‐based downscaling method can be used at multiple locations without relying on detailed local observations. The evaluated downscaling method is developed on the basis of empirical orthogonal function (EOF) analysis of space–time soil moisture data at a reference catchment. The most important EOFs are then estimated from topographic attributes, and the associated expansion coefficients are estimated on the basis of the spatial‐average soil moisture. To test the portability of this EOF‐based method, it is developed separately using four data sets (Tarrawarra, Tarrawarra 2, Cache la Poudre and Satellite Station), and the relationships that are derived from these data sets to estimate the EOFs and expansion coefficients are compared. In addition, each of these downscaling methods is applied not only for the catchment where it was developed but also to the other three catchments. The results suggest that the EOF downscaling method performs well for the location where it is developed, but its performance degrades when applied to other catchments. Copyright © 2011 John Wiley & Sons, Ltd.