Variation of stream temperature among mesoscale habitats within stream reaches: southern Appalachians

Stream mesoscale habitats have systematic topographic relationships to hyporheic flow patterns, which may create predictable temperature variation between mesoscale habitat types. We investigated whether systematic differences in temperature metrics occurred between mesoscale habitats within reaches of small streams tributary to the upper Little Tennessee River, southern Appalachians. Surface water temperature was recorded over three or four mid‐summer days in four mesoscale habitat types: riffle, main riffle, pool and alcove in 44 stream segments (sites). Temperature metrics were calculated for each mesoscale habitat relative to the mean value of the metric over the stream: Δ maximum temperature, Δ average maximum temperature and Δ maximum daily variation and also for each site: standard deviation of the maximum temperature and average diurnal variation (ADV). Sites were categorized as fully or partially forested. Pool tailouts had statistically significantly lower Δ maximum temperature and Δ average maximum temperature than riffle tailouts in partially forested sites, although differences were small. This was the opposite of what was expected in the presence of hyporheic exchange, indicating hyporheic exchange is not a dominant driver of mesoscale habitat temperatures at these sites. Temperature differences between mesoscale habitat units were small and unlikely to have ecological significance. We also evaluated relationships between stream temperature and riparian condition, watershed % impervious surfaces, watershed % non‐forested and elevation. ADV and standard deviation of the maximum temperature were significantly higher in partially forested sites, indicating that partially forested sites have greater temperature ranges and spatial variation of maximum temperatures. ADV decreased with elevation and increased with % impervious surfaces. Copyright © 2013 John Wiley & Sons, Ltd.     

卫星云图、雷达回波在人工增雨时机选择中的应用

概述了干旱期间选择飞机和高炮人工增雨作业时机的方法，以2000年6～7月哈尔滨地区特大干旱期间进行的飞机和高炮人工增雨作业为例，利用卫星云图和雷达回波资料选择的作业时间和作业区域应是比较有利的。因为从卫星云图中的水汽图、红外和可见光云图上可分析出云系中的含水量、云顶温度、云系强度，在此基础上利用天气雷达跟踪订正，可直接指挥飞机和高炮在有利的区域和时间内进行作业，获得了明显的效果。     

京西木城涧矿区窑坡组沉积体系及相关聚煤因素

通过实测剖面、岩矿鉴定、编制沉积断面图、砂体和煤层等厚图等资料分析,从京西木城涧矿区窑坡组中识别出湖泊沉积体系、河流沉积体系和沼泽沉积体系,并详细阐述了其成因相的岩相构成;在此基础上,指出窑坡组沉积早期为湖泊环境,主体沉积期为总体NE流向的网结河环境,其间伴随湖泊或河流周期性消亡而大面积泥炭沼泽化形成了稳定的可采煤层和含煤沉积旋回。富煤带总体呈NE50°～80°展布,与泥炭沼泽沉积期下伏不同沉积相的压实效应有关,后者通过影响地表起伏和积水深度,控制着泥炭的堆积速率和厚度。     

PHoToNs–A parallel heterogeneous and threads oriented code for cosmological N-body simulation

We introduce a new code for cosmological simulations, PHo To Ns, which incorporates features for performing massive cosmological simulations on heterogeneous high performance computer(HPC) systems and threads oriented programming. PHo To Ns adopts a hybrid scheme to compute gravitational force, with the conventional Particle-Mesh(PM) algorithm to compute the long-range force,the Tree algorithm to compute the short range force and the direct summation Particle-Particle(PP) algorithm to compute gravity from very close particles. A self-similar space filling a Peano-Hilbert curve is used to decompose the computing domain. Threads programming is advantageously used to more flexibly manage the domain communication, PM calculation and synchronization, as well as Dual Tree Traversal on the CPU+MIC platform. PHo To Ns scales well and efficiency of the PP kernel achieves68.6% of peak performance on MIC and 74.4% on CPU platforms. We also test the accuracy of the code against the much used Gadget-2 in the community and found excellent agreement.     

基于3维可视化环境的地质体空间形态分析

针对3维矿床地质体既具有复杂的几何形态特征,又具有连续的矿化分布与控矿作用分布等空间分布场特征,结合3维地质建模软件Datamine的可视化环境,基于线框模型研究了地质体实体建模与3维可视化过程;在此基础上将实体模犁离散化输出为体素模型,提出采用趋势面分析方法和基于数学形态学的分析方法进行地质体空间形态分析,比较和研究了这两种方法提取地质体空间趋势形态和形态起伏特征的过程.实例研究和论证了基于数学形态学滤波的地质体空间形态因素分析和提取方法处理某方向上存在有超覆现象的可行性.     

甘肃陇山地区葫芦河群变质玄武岩及大地构造环境恢复

葫芦河群变质玄武岩以其高不相容元素、稀土元素和低MgO、Cr和Ni含量有别于现代洋中脊玄武岩和岛弧玄武岩,在FeO-MgO-Al_2O_3和Ti/100-Zr-Y×3判别图上,均落在大陆玄武岩区。在剖面上,与变质玄武岩整合接触的巨厚的变砂岩和大量出现的火山角砾岩和集块岩是浅海环境的标志;密集的辉绿岩墙群是拉张性大地构造环境的特征。因此,本文认为葫芦河群变质玄武岩原岩形成于陆内裂陷海盆环境。     

农田土壤湿度的人工神经网络预测诊断系统

采用人工神经网络（ＡＮＮ）方法，研制了农田土壤湿度预测，诊断分析系统，该系统根据不同的土壤湿度特点和影响因子，可自动提供时间序列拓展的人工神经网络预测模型和人工神经网络的混合预测模型进行土壤湿度的动态预测。并提供不同降水量的土壤湿水分渗透深度诊断分析，系统采用中文菜单显示的人机对话方式操作，使具有准动力学特性，多种可调参数和网络结构的ＡＮＮ方法变得简便易于操作。实际使用表明，该系统对土壤湿度的预测     

姬塬地区长8油层组层序地层格架内成岩相展布特征

通过岩心观察并充分利用普通薄片、铸体薄片、阴极发光、X-衍射和扫描电镜等资料,对姬塬地区长8油层组储层的成岩作用、成岩矿物、成岩阶段和成岩演化序列特征等进行了研究。根据成岩作用类型及强度、成岩矿物等将储层划分为绿泥石衬边弱溶蚀、不稳定组分溶蚀、压实致密、高岭石充填和碳酸盐胶结5种成岩相。并通过岩心薄片资料刻度测井归纳出不同成岩相在GR、AC等测井曲线及其组合上的响应特征,由此实现各单井储层成岩相的连续划分。对长8油层组层序界面和基准面旋回与成岩相展布的关系进行了研究,结果表明层序界面附近不稳定组分溶蚀相及高岭石充填相较为发育,且各井之间对比性良好,同时层序界面也控制了碳酸盐胶结;中期基准面旋回的最大湖泛面处均发育井间可对比的压实致密相,长82中期基准面下降半旋回砂体一方面易于遭受溶蚀产生次生孔,另一方面由于受沉积驻留和碎屑组分影响导致压实强度较弱,因此物性总体比长81砂体好。     

2008年1月贵州冻雨的数值模拟和层结结构分析

针对2008年初发生在贵州地区的严重冻雨过程,分别从环流背景、低空急流和水汽输送条件等方面分析了准静止锋维持的原因,并选取本次灾害最严重的第3次过程为典型个例,利用WRF模式针对准静止锋影响下的贵州冻雨进行数值模拟来研究冻雨的发生机制。模拟结果较好地反映出高低空环流形势场特征,强雨雪降水带的走向、落区,以及地面温度的分布,均与观测基本吻合。通过分析高分辨率模式的模拟结果,揭示了准静止锋上贵州地区冻雨的层结结构特征及云物质在冻雨区的分布特征。研究结果表明,贵州中部的冻雨区除一般的三层结构(包含冰晶层、暖层和冷层)外,还具有典型的两层结构特征,即:高空的固体降水粒子稀少,900~600 h Pa深厚的逆温层和0℃以上的暖层使中低空存在大量液态粒子,下落的液滴经过近地面的浅薄冷层,形成大量过冷却雨滴,而后降落至地面迅速冻结。     

The hydrodynamical characteristics of nearshore waters and the discharging process of mud flats— A case study of the mud flats near Lianyungang,China

It is apparent that there is a difference between mud coasts and sand coasts in such aspects as sediment components, hydrodynamics of nearshore waters, and the formative process in configuration, and profile. The intensity distribution of waves affecting the mud flats in Lianyungang, and the conditions determining tidal water levels, are discussed in this paper. A mathematical model which describes the erosion process of mud flats has been derived on the basis of the results of tests for the mud process in seawater. The model is satisfactory for the actual mud flat profile change in Lianyungang with artificial mud discharges.