Low‐cost monitoring of snow height and thermal properties with inexpensive temperature sensors

Small, self‐recording temperature sensors were installed at several heights along a metal rod at five locations in a case study catchment. For each sensor, the presence or absence of snow cover was determined on the basis of its insulating effect and the resulting reduction of the diurnal temperature oscillations. Sensor coverage was then converted into a time series of snow height for each location. Additionally, cold content was calculated. Snow height and cold content provide valuable information for spring flood prediction. Good agreement of estimated snow heights with reference measurements was achieved and increased discharge in the study catchment coincided with low cold content of the snow cover. The results of the proposed distributed assessment of snow cover and snow state show great potential for (i) flood warning, (ii) assimilation of snow state data and (iii) modelling snowmelt process. Copyright © 2010 John Wiley & Sons, Ltd.     

Comparison of genetic algorithms and shuffled complex evolution approach for calibrating distributed rainfall–runoff model

Three methods, Shuffled Complex Evolution (SCE), Simple Genetic Algorithm (SGA) and Micro‐Genetic Algorithm (µGA), are applied in parameter calibration of a grid‐based distributed rainfall–runoff model (GBDM) and compared by their performances. Ten and four historical storm events in the Yan‐Shui Creek catchment, Taiwan, provide the database for model calibration and verification, respectively. The study reveals that the SCE, SGA and µGA have close calibration results, and none of them are superior with respect to all the performance measures, i.e. the errors of time to peak, peak discharge and the total runoff volume, etc. The performances of the GBDM for the verification events are slightly worse than those in the calibration events, but still quite satisfactory. Among the three methods, the SCE seems to be more robust than the other two approaches because of the smallest influence of different initial random number seeds on calibrated model parameters, and has the best performance of verification with a relatively small number of calibration events. Copyright © 2009 John Wiley & Sons, Ltd.     

基于图论算法的单元上布线

Pal等提出一个纯粹的图论算法体系TAH（Track Assignment Heuristic），该算法用理想的或接近理想的轨道数解决了许多非常有名的通道布线的例子，其中有两层VH通道布线模型、三层HVH通道布线模型、多层Vi-Hi和ViHi＋1通道布线模型，这种算法推广应用到了两层和三层的单元上布线中，实验结果表明取得了良好的效果。     

确定全球厘米级精度大地水准面的可能性和方法探讨

阐述确定厘米级精度大地水准面所面临的挑战,评述各种大地水准面的定义,提出一种确定1°×1°厘米级精度全球大地水准面的新思路和新方法:在已知相应厘米级精度全球重力位模型、地形密度分布模型以及平均海面高模型的前提下,利用虚拟压缩恢复法可实现全球1°×1°厘米级精度大地水准面的目标。初步论证实现此目标的可能性和条件,并简要介绍一个模拟实验结果。     

顾及多尺度分割参数的FNEA面向对象分类

首先对分形网络演化（FNEA）算法做了介绍,通过试验对比4种分割方法棋盘分割、四叉树分割、多尺度分割、光谱差异分割的效果。此外,通过eCognition Developer 8.7分析软件对影像进行多尺度分割预处理,从5开始,以5为单位向上递增,共选取12组参数进行分割试验,采用面向对象CART分类器对分割后影像分类。对比分类效果图可知,小尺度分割参数对分类效果能有较好的提升;对比总体精度及Kappa系数可知,小尺度分割参数分类精度优于大尺度分割参数,且当分割参数Scale为10时,分类精度达到最好的级别。     

甘肃玛曲大水金矿田控矿因素及主矿体特征对比分析

大水金矿田由大水、贡北、格尔托3处大、中型金矿床组成,经过30年巨量探矿工程的投入和持续有效的勘查与研究,整体达到了详查程度,累计查明金资源量约130 t,为典型矿床对比研究提供了理想基地。通过大水金矿田赋矿地层岩性、控矿断裂构造、成矿侵入岩等控矿因素的对比分析认为：大水金矿田赋矿地层岩性以中三叠统马热松多组灰岩为主;控矿断裂、成矿容矿脉岩及其所赋存矿体的规模,以大水特大型金矿明显优于贡北、格尔托中型金矿,大水金矿主要以NWW向压扭性主干断裂与近SN向放射状张性断裂的交汇部位控制厚富主矿体,贡北以EW向、格尔托以NNW与NE向断裂的交汇部位控制主矿体的分布;中酸性岩体及其派生的酸性岩脉与金成矿关系密切,容矿花岗闪长岩（斑）岩脉及其蚀变方解石大脉在陡倾断裂破碎带中的集中分布,往往指示厚富金矿体的赋存地段。通过3个矿区主矿体的规模、品位、资源量分布等特征的对比分析可以看出,主矿体的规模、品位以大水较贡北、格尔托为大、为富,大水、贡北、格尔托金矿的主矿体资源量分别占矿区的75. 62%、78. 51%和79. 58%,且由普查到详查,主矿体资源量占比有所变化,如大水金矿由70. 59%增加到75. 63%,贡北金矿则由88. 24%降低为84. 16%。     

《北京西山地质志》中、英文本比较研究

依据文本对勘的方法,从图片和文字两个方面对《北京西山地质志》中、英文本进行比较研究。图片方面,英文本作了大量的增补和解说,内容更为详实准确。文字方面,中、英文本目录存在明显差异。英文本序言和注释有其独到的价值和意义。中文本正文的细节增补,应是吸收了当时的最新研究成果。中、英文本比较研究为认识《北京西山地质志》的价值与地位提供了准确可靠的学术依据。     

基于多源多时相遥感数据的秋季菜田监测与分析——以北京市大兴区为例

根据北方蔬菜种植生育期特点,选择7~8月份的高分1号(GF1)融合影像、10月份的16 m宽覆盖的GF1影像以及8月份Rapid Eye融合影像,结合耕地本底数据开展提取秋季菜田信息的技术流程研究,并对2013年和2014年大兴区秋季菜田进行了动态监测,同时结合气象等数据分析其时空分布规律和变化原因。     

Concentrations of railway metal theft and the locations of scrap-metal dealers

Metal theft has become a substantial crime problem in many areas. In response, several countries have introduced legislation to regulate scrap-metal recycling yards. However, at present there is little evidence to support this use of the market reduction approach (MRA) in preventing metal theft. The present study sought to test the underlying assumption of the MRA that the presence of a market for stolen property (in this case provided by scrap yards) drives thefts in a local area. This study tested for a spatial association between the locations of scrap yards and those of metal thefts. The density of industry, local burglary rate and road-accessibility of an area were controlled for. Metal thefts from railway lines in England were shown to be significantly more common in areas with more scrap-metal yards, high road accessibility and high population density. The results support the use of the MRA in relation to metal theft.     

新特提斯缝合带中段豆荚状铬铁矿成矿规律对比研究

新特提斯缝合带中的铬铁矿带是全球最重要的豆荚状铬铁矿成矿带之一,尤其是新特提斯缝合带中段,即穆斯林巴赫-科希斯坦-雅鲁藏布江一带,自东向西发育罗布莎、马拉坎德、穆斯林巴赫等若干大型铬铁矿床。本文系统总结和梳理新特提斯缝合带中段蛇绿岩的时空分布特征以及典型豆荚状铬铁矿的矿床特征、赋存规律和控矿因素。研究表明,蛇绿岩形成时代主体为中侏罗世—晚白垩世,自东向西大致呈逐渐变新的趋势,构造侵位的时代相近,为古新世—始新世;马拉坎德、瓦济里斯坦、穆斯林巴赫及贝拉铬铁矿,与罗布莎矿床相似,均属于富铬型铬铁矿,产于SSZ相关构造背景下,显示良好的岩相分带,具有良好的成矿条件;提出下一步找矿方向是针对成矿条件优越的蛇绿岩,解析层序剖面,识别纯橄岩与方辉橄榄岩的岩相分带,确定有利赋矿岩相。