雨滴尺度谱谱参数和形状因子的分析

作者计算了３次降不过程的雨滴尺度谱参数，并进行Ｍ－Ｐ分布拟合和Г分布拟合。同时还计算了雨滴谱形状因子Ｓ（Ｚ，Ｒ），分析了形状因子与雨强之间的关系。     

纬向平均的风向改变指数与季节转换

通过定义一个能客观定量描述大气环流四维时空变化的风向改变指数WI,用以研究大气环流的时空演变规律和季节转换。在对纬向平均的WI做了经验正交函数(EOF)分析后,得到了其前四个模态。第一模态揭示的是全年平均的WI空间分布的基态。第二模态反映的是WI场的偏差中呈现准调和变化的部分,热带、副热带、温寒带季风区在该模态中均有明显体现。第三模态反映的是WI场的偏差中呈现非调和变化的部分,该部分揭示了因南北半球海陆分布的差异和因大气、海洋流体的非线性效应,其所造成的从春到秋与从秋到春的季节变化的不对称性以及平流层的二月突变现象。第四模态反映的是全球各层盛行风反向区域从春到夏的北进和从夏到秋南撤的现象。     

GIS and remote sensing integration for environmental applications

Abstract

The combined use of remotely-sensed images and vector GIS data has received considerable interest in recent years. This review article discusses the historical move towards closer integration of remote sensing and GIS technologies and the requirements of integrated software systems to enable remotely-sensed data to be combined with vector datasets for maximum effect. The benefits of integration to users of both GIS and remote sensing for environmental applications are reviewed and some thoughts are given on terminology and future directions in this field.     

An object-based conceptual framework and computational method for representing and analyzing coastal morphological changes

This article presents an object-based conceptual framework and numerical algorithms for representing and analyzing coastal morphological and volumetric changes based on repeat airborne light detection and ranging (LiDAR) surveys. This method identifies and delineates individual zones of erosion and deposition as discrete objects. The explicit object representation of erosion and deposition zones is consistent with the perception and cognition of human analysts and geomorphologists. The extracted objects provide ontological and epistemological foundation to localize, represent, and interpret erosion and deposition patches for better coastal resource management and erosion control. The discrete objects are much better information carriers than the grid cells in the field-based representation of source data. A set of spatial and volumetric attributes are derived to characterize and quantify location, area, shape, orientation, depth, volume, and other properties of erosion and deposition objects. Compared with the conventional cell-by-cell differencing approaches, our object-based method gives a concise and high-level representation of information and knowledge about coastal morphological dynamics. The derived attributes enable the discrimination of true morphological changes from artifacts caused by data noise and processing errors. Furthermore, the concise object representation of erosion and deposition zones facilitates overlay analysis in conjunction with other GIS data layers for understanding the causes and impacts of morphological and volumetric changes. We have implemented a software tool for our object-based morphological analysis, which will be freely available for the public. An example is used to demonstrate the utility and effectiveness of this new method.     

吉林省村域尺度下居民点空间分布特征及优化重组模式

乡村聚落的空间优化与重构是提高土地资源利用效率,改善农村生产生活条件,促进乡村可持续发展的重要手段。以吉林省为例,采用核密度估计方法和景观形状指数分析了农村居民点空间分布特征,基于农户调查数据估算了吉林省不同区域的农村宅基地闲置情况,将农村居民点长期存在的“破碎化”和日益突出的“空心化”相结合,提出了在行政村尺度下农村居民点优化重组的“整小填大”新模式。结果表明：① 吉林省农村居民点规模小且零散分布,尤其中部呈破碎化分布,形态不规则,具有较大的整治潜力;② 吉林省农村宅基地平均闲置率为18.32%,西部地区最高（24.48%）,分别高于东部和中部地区约6%和12%;③“整小填大”模式可使农村居民点数量减少44.6%,增加有效耕地面积1 046.66 km²。     

滑坡钢筋砼格构防治"倒梁法"内力计算研究

格构锚固技术能有效地控制滑坡深部和浅表破坏,提高锚固体系的整体刚度。目前在格构 锚杆体系的设计中,大多采用经验设计钢筋砼格构,常导致配筋不合理,不仅造成浪费,而且可能埋下工程隐患。本文采用“倒梁法”对格构梁的内力计算方法进行研究,对滑坡防护钢筋格构进行如下简化:(1)锚杆对格构梁的作用以垂向力为主,轴向力可以忽略不计。(2)纵向格构梁的刚度大于横向格构梁的刚度,因而横向格构梁的内力计算可以简化,钢筋砼格构可以作为在锚杆施力下的超静定连续梁。结合三峡工程库区巫山新城秀峰寺滑坡格构防护工程设计,通过“三弯矩方程”进行了格构梁内力实例计算,为格构梁的合理设计提供了依据。     

Transport rate of calcareous sand in unidirectional flow

This paper examines the transport of calcareous sand in unidirectional flow and its prediction through existing sediment transport models. A flume experiment of four sand samples collected on Oahu, Hawaii, provides 29 sets of sediment transport data in the bed-form and suspended transport stages. The measured transport data are compared with direct predictions from four energy-based transport models developed for siliceous particles. Corrections for the grain-size, fall velocity, and critical velocity of calcareous sand based on recent research are applied to the models and the results are compared with the direct calculations and measured data. The comparison illustrates the important role particle shape plays in the transport of calcareous sand. All four sediment transport models give consistent predictions and good agreement with the majority of the measured data. Two of the models respond positively to the corrections in both the bed-form and suspended transport stages indicating that such an approach may provide an interim solution for the transport of calcareous sand.     

空气反循环连续取样施工中卡钻事故的预防与处理

利用空气反循环连续取样钻进技术,在露天矿山进行生产勘探施工,对所遇到的卡钻问题进行原因分析,确定了相应的操作规程,以便预防卡钻事故的发生,并通过施工辅助孔和套铣技术,在处理卡钻事故方面取得了很好的效果。     

Shell‐shape and morphometric variability in Mytilus galloprovincialis from micro‐tidal environments: responses to different hydrodynamic drivers

Tidal conditions differently influence inter‐tidal organisms in terms of general physiological and metabolic responses. In this study we investigated the morphological response in shells of Mytilus galloprovincialis native to different micro‐tidal coastal environments in the Northern Adriatic Sea. Our purpose was to highlight the ecophenotypic variability across tidal levels and to elucidate how tidal currents and waves produced by anthropogenic activities may play a part in modulating shell morphology. Three sampling sites were selected: an open‐sea area 15 km off‐shore and two sites within the lagoon of Venice, the first near one of its three inlets, and the other one in the proximity of Venice city centre. At each sampling site, organisms were seasonally collected at different depths within their vertical zonation, either in the inter‐tidal zone – i.e. at both the highest and lowest tide zonation limits, and subtidally. The mussel shells were analysed by investigation of their morphometric relationships (height/length and width/length ratios) and by elliptic Fourier analysis of the shell contours. Shell thickness and condition index were also evaluated for a better comprehension of energy allocation/partitioning. Estimates based on long‐term measurements, visual observation, wind statistics and wave growth laws allowed an evaluation of the forces acting on shells. At the open‐sea site, the observed phenotypic variability of both shell shape and thickness was clearly related to the tidal vertical zonation. At the two lagoon sites, the currents generated by tidal flow through the inlet and the waves caused by the frequent passage of boats influenced both shell shape and thickness. A trade‐off between protection and growth was apparent along the tide gradient, as emphasized by the differences in the partitioning and allocation of energy between shell and flesh production.     

多维地震作用下大跨空间结构的减震控制分析

考虑到多维地震输入对网架结构的不利影响,基于形状记忆合金超弹性,研制出一种兼具自复位、高耗能及放大功能于一体的形状记忆合金复合黏滞阻尼器(Hybrid Shape Memory Alloy Viscous Dampers,简称HSMAVD),并通过试验研究该阻尼器在循环荷载作用下的力学性能;然后以平面四角锥网架模型为基础,将该阻尼器替换部分网架结构杆件,并分析该阻尼器减震控制效果。结果表明形状记忆合金与黏滞阻尼器复合后具有良好的协同工作能力,可有效发挥形状记忆合金的超弹性和黏滞阻尼器的速度相关特性,使其具有稳定的滞回性能和良好的耗能能力;采用阻尼杆件替换原杆件的方法既能对结构进行有效的减震控制,又不改变原有的结构形式,是一种优越的减震控制方法,并为HSMAVD被动控制系统在结构抗震中的实际应用提供新思路。