城乡融合背景下半城市化地区识别与演变研究——以苏州市为例

半城市化地区作为城乡景观混杂交错、城乡功能相互渗透的过渡性地域,推进这类地区的良性发展是促进城乡融合发展的关键。对半城市化地区空间范围的精确识别是对其实施精准管控的基础前提,对半城市化地区演变规律的科学把脉可为其未来的发展规划提供重要参考。然而,由于半城市化地区的复杂性、动态性和模糊性,目前对该类地区的精细尺度定量识别研究不多。基于此,论文综合考虑半城市化地区的复杂多维特征,在多源遥感数据支持下,建立了一种高精度的半城市化地区识别方法体系：① 构建了一套覆盖社会经济和空间格局2大维度的半城市化地区识别综合指标体系;② 运用空间网格化技术和线性加权建立了半城市化特征值的计算方法; ③ 结合滑动t检验与概率密度分析实现了半城市化特征临界值的确定。最后以苏州市为实例,运用建立好的方法体系,在1 km×1 km尺度下识别出了该市2010、2015和2018年的半城市化地区空间范围,并在此基础上进一步探讨了其时空演变规律,以期为苏州市以及其他地区未来的城市化进程提供参考。实证结果显示,苏州市的半城市化地区在空间上围绕中心城区不连续分布,在时间上总体呈现减少趋势,尤其是2015—2018年间下降幅度明显,表明苏州市城镇化发展趋于有序,乡村工业化与城市的无序蔓延有所放缓。     

Religious composition of Punjab's urban population, 1981

The author analyzes the religious composition of the urban population in Punjab, India, for the period 1971-1981. Aspects considered include the relationship between religious composition and size-class of urban centers, changes in the size of urban religious populations, and the different spatial patterns of various religious communities.     

二维有限差分时间域电磁偏移

我们已推出一种二维有限差分时间域（ＦＤＴＤ）偏移算法,有限差分方法的优点在于它能很地应用于各种电导率背景模型,比较ＦＤＴＤ算法和积分方程（ＩＥ）算法的电磁偏移计算结果表明,有限差分法结果比ＩＥ结果能更好地反映电导异常,对于含有榀 的数据也可提供稳定的图像。Ｍｉｎｄｃｏ的地球物理学家们,跨跃日本的Ａｗａｊｉ岛的Ｎｏｊｉｍａ断裂带,开展了ＴＤＥＭ法工作,并利用有限差分偏移方法测定了与断裂有关的导电破碎     

The dust coma of Comet P/Giacobini-Zinner in the infrared

We present 1-20 micrometers photometry of P/Giacobini-Zinner obtained at the NASA Infrared Telescope Facility, during 1985 June-September (r = 1.57-1.03 AU). A broad, weak 10 micrometers silicate emission feature was detected on August 26.6; a similar weak emission feature could have been hidden in the broadband photometry on other dates. The total scattering and emitting cross section of dust in the inner coma was similar to that in other short-period comets, but a factor of 10 (r = 1.56 AU) to 100 (r = 1.03 AU) lower than the amount of dust in Comet Halley. The thermal emission continuum can be fit with models weighted toward either small or large absorbing grains. The dust production rate near perihelion was approximately 10(5) g/s (small-grain model) to approximately 10(6) g/s (large-grain model). The corresponding dust/gas mass ratio on August 26 was approximately 0.1-1. A silicate-rich heterogeneous grain model with an excess of large particles is compatible with the observed spectrum of Giacobini-Zinner on August 26. Thus, weak or absent silicate emission does not necessarily imply an absence of silicates in the dust, although the abundance of silicate particles < or = 1 micrometer radius must have been lower than in Comet Halley.     

The organochlorine contamination history of the Mersey estuary, UK, revealed by analysis of sediment cores from salt marshes

Sediment profiles in the Banks, Ince and Widnes Warth salt marshes in Northwest England contain a mappable record of historic pollution. For persistent organochlorine compounds this stretches back over 90 years. The PCB and HCH profiles can be successfully rationalised by dating methods, and they can be related to the dates of initial production and subsequent withdrawal from use of these chemicals as a result of restrictive environmental legislation. HCB has a more complex pollution profile as it has been manufactured in Northwest England, both deliberately as a pesticide and accidentally as a by-product of several chlorination processes, dating back to the start of the 20th century. The concentrations of degradation products of DDT are relatively constant through the sediment profile and are dominated by op'- and pp'-DDD with only minor contributions from the most toxic species, pp'-DDT. The quantities of these compounds resident in the reservoir of pollutants under these marshes have been calculated, and have fallen progressively in the last 30-50 years.     

对舟山围涂的思索——从顺母围涂谈起

解放以来,舟山人民与沧海争地,发动千军万马,共围海涂15.8万亩,其中改造为田地的3.3万亩,盐田6.5万亩,用于海水养殖2.1万亩,已围涂总利用率75％以上。其对缓解海岛的土地缺少、乡村剩余劳力的安排和出口创汇起了重要作用。然而,在众多的围涂工程中,也有少数工程在经济效益和社会效益、生态效益的权衡中,弊明显地超过了利,从长远的角度考虑,严格地     

ActiveX技术在海洋声信号处理中的应用

在Visual Basic6．0中应用ActiveX技术与Matlab混合编程，来处理海洋水声信号及海洋环境噪声实测数据，能够发挥各自的软件优势，既实现软件运行的无缝联接，又能大大简化繁琐的数据计算。     

改进总体最小二乘迭代解法在病态平差模型中的应用

讨论了总体最小二乘法在解病态矩阵中的问题。利用改进后的总体最小二乘迭代算法研究测量平差在病态方程中的应用。实验证明,该算法解决了方程的病态性,且精度与最小二乘方法具有一致性。     

锦屏一级坝基岩体质量爆破开挖损伤评价

锦屏一级水电站大坝为双曲拱坝,设计坝高305m,拱坝建基岩体以Ⅱ、Ⅲ₁级岩体为主,开挖过程中岩体质量受爆破开挖影响发生程度不等的损伤。为定量评价岩体质量损伤等级,利用开挖爆破检测成果,采用开挖后岩体松弛深度、松弛岩体开挖前后单孔声波衰减率作为岩体质量损伤分级评价的指标,探索一种快速检测、评价岩体质量损伤等级的划分标准,完成坝基开挖后岩体质量损伤的分级分区评价,提出不同损伤等级处理的建议,并评价处理效果。