威海市海产加工企业时空演变及选址影响因素研究

海洋渔业是海洋产业中开发利用最早的产业之一,在整个国民经济中占据重要地位。文章运用核密度分析法以及负二项分析方法,对2000-2020年威海市海产加工企业的时空演变特征及新增海产加工企业选址的影响因素进行分析。分析结果表明：威海市海产加工业的集聚核心逐渐由单一核心向双核心演变;前期海产加工企业集聚主要受地理因素的影响,后期多因政策、经济等因素产生集聚;街道内原有海产企业数量以及与高速收费站的距离均是影响新增海洋渔业企业选址的因素。     

中国铁路客运流联结的城市时间可达性

基于中国铁路客户服务中心提供的客运流数据,采集全国地级以上行政单元(未含港澳台数据)间铁路客运运行的最短历时,基于GIS网络分析和空间分析等方法,选取时间可达性和一日交流圈2个指标对城市可达性进行测度和分析。研究发现:①城市时间可达性水平划分为7个级别,在空间上呈现中心-外围式圈层结构,中心区域沿铁路干线和高速铁路线轴向扩展,廊道效应明显,东部、中部地区的城市时间可达性优于西部地区。②城市之间的时间可达性小于2.0 h的城市对在空间上构成了由京广、京沪、京哈、京福、杭深、青太、徐兰、沪汉蓉、沪昆、广昆等高速铁路连接的"五纵五横"带状分布格局。时间可达性小于10.0 h的城市对覆盖了"胡焕庸线"东南部的大部分区域,城市带转为城市网络。③直辖市、省会/首府城市一日交流圈以31个城市为中心,按照时间可达性由小到大呈现轴向扩展,廊道效应明显。基于城市一日交流圈划分了19个城市群和拉萨城市圈,为城市群的划分提供方法借鉴。     

中国城市化过程中生态环境研究的文献计量分析

中国城市化过程中生态环境研究成果丰富,总结其演变过程利于把握该领域现状与趋势。本文从城市化文献视角对中国城市化过程中的生态环境研究在研究成果、研究子领域、研究主题、理论和方法等方面进行总结。结果表明,从2005年起中国城市化文献中关于生态环境的研究呈加速增长的态势;资源领域的国土资源和产业子领域,生态领域内经济子领域和环境领域内气候和城市环境子领域受到了较多的关注;＂土地利用＂和＂热岛效应＂一直是最热的关键词,分别占全部关键词出现频次的0.15%和0.09%,＂热岛效应＂和＂气候变化＂则是近期热点;主要理论涉及生态学、数理模型、资源与环境经济学、环境科学等,其中生态足迹理论从2002年起一直占据主流,STIRPAT模型、环境库兹涅茨曲线等综合理论模型是近期热点理论;依方法来源和主要应用领域将1992-2011年主要方法分为4类,即统计类（65.17%）、系统类（13.11%）、机理类（11.79%）和测评类（9.93%）。灰色系统分析和R/S分析近年来常见的方法。由此得出主要结论：中国城市化研究对城市土地利用、城市热岛、气候变化和水资源等大尺度的生态环境问题更加重视,对城市环境健康等微观尺度生态环境问题关注相对不足;以STIRPAT和多种土地利用变化模型为代表,综合自然和经济理论采用系统建模方法评价和模拟城市化过程中的生态环境效应将是未来研究的重点。     

丘陵地貌区高程内插适宜方法选择——以长春净月潭为例

对不同的地貌区进行空间内插时选择的适宜方法不同,以典型丘陵地貌区长春市净月潭地区的高程为研究对象,用ArcGIS 9.2分别作反距离权重法、最近邻点法、趋势面分析和克里金法做高程内插。应用交叉检验方法对其内插的精度作出分析,检验其科学性和可靠性,得出反距离权重法、最近邻点法、趋势面法、样条函数法和克里金法高程内插的不同精度,并对各种方法的适用性进行讨论。结果表明最近邻点法精度最高,以下依次为普通克里金插值法、样条函数、反距离权重法、趋势面法。为类似于净月潭地区的丘陵地貌区高程内插提供选择参考。     

长牡蛎基因组微卫星引物的开发和特性描述

长牡蛎于20世纪80年代从日本引进中国.在我国,长牡蛎已经成为重要的贝类养殖产业之一.本实验从全基因组上筛查微卫星序列,在微卫星筛查的范围、数目和类型上是传统的富集文库法开发微卫星所无法比拟的.利用基因组微卫星序列总共设计了104对引物,54对引物能扩增出目的片段,其中有34对引物显示多态性扩增,占32.7％,20对引...     

阿尔金山北段晚新生代山体抬升的裂变径迹证据

对阿尔金山北段阿克塞 当金山口剖面的裂变径迹研究结果表明 ,该区晚新生代 8Ma左右曾发生较快速抬升。抬升年龄的展布与阿尔金左行走滑断裂带晚期活动在该区所呈现的正花状构造相吻合。     

湘赣边界鹿井铀矿床流体包裹体及成矿机制

位于南岭成矿带南西部的鹿井矿床是华南热液型铀矿的典型代表.为查明其成矿流体来源、性质与演化以及成矿机制,开展了不同成矿阶段石英、萤石及方解石中流体包裹体的显微测温和不同阶段石英的氢?氧同位素分析.矿床地质特征表明成矿过程可划分为(I)粗晶石英+黄铁矿±绿泥石±绢云母、(II)沥青铀矿+硫化物+绿泥石+绢云母+暗灰色微晶...     

Evaluation of a Photosynthesis-Based Canopy Resistance Formulation in the Noah Land-Surface Model

Accurately representing complex land-surface processes balancing complexity and realism remains one challenge that the weather modelling community is facing nowadays. In this study, a photosynthesis-based Gas-exchange Evapotranspiration Model (GEM) is integrated into the Noah land-surface model replacing the traditional Jarvis scheme for estimating the canopy resistance and transpiration. Using 18-month simulations from the High Resolution Land Data Assimilation System (HRLDAS), the impact of the photosynthesis-based approach on the simulated canopy resistance, surface heat fluxes, soil moisture, and soil temperature over different vegetation types is evaluated using data from the Atmospheric Radiation Measurement (ARM) site, Oklahoma Mesonet, 2002 International H₂O Project (IHOP_2002), and three Ameriflux sites. Incorporation of GEM into Noah improves the surface energy fluxes as well as the associated diurnal cycle of soil moisture and soil temperature during both wet and dry periods. An analysis of midday, average canopy resistance shows similar day-to-day trends in the model fields as seen in observed patterns. Bias and standard deviation analyses for soil temperature and surface fluxes show that GEM responds somewhat better than the Jarvis scheme, mainly because the Jarvis approach relies on a parametrised minimum canopy resistance and meteorological variables such as air temperature and incident radiation. The analyses suggest that adding a photosynthesis-based transpiration scheme such as GEM improves the ability of the land-data assimilation system to simulate evaporation and transpiration under a range of soil and vegetation conditions.     

Impact of updraft on neutralized charge rate by lightning in thunderstorms: A simulation case study

The rate of neutralized charge by lightning (RNCL) is an important parameter indicating the intensity of lightning activity. The total charging rate (CR), the CR of one kind of polarity (e.g., negative) charge (CROP), and the outflow rate of charge on precipitation (ORCP) are proposed as key factors impacting RNCL, based on the principle of conservation of one kind of polarity charge in a thunderstorm. In this paper, the impacts of updraft on CR and CROP are analyzed by using a 3D cloud resolution model for a strong storm that occurred in Beijing on 6 september 2008. The results show that updraft both promotes and inhibits RNCL at the same time. (1) Updraft always has a positive influence on CR. The correlation coefficient between the updraft volume and CR can reach 0.96. Strengthening of the updraft facilitates strengthening of RNCL through this positive influence. (2) Strengthening of the updraft also promotes reinforcement of CROP. The correlation coefficient between the updraft volume and CROP is high (about 0.9), but this promotion restrains the strengthening of RNCL because the strengthening of CROP will, most of the time, inhibit the increasing of RNCL. (3) Additionally, increasing of ORCP depresses the strengthening of RNCL. In terms of magnitude, the peak of ORCP is equal to the peak of CR. Because precipitation mainly appears after the lightning activity finishes, the depression effect of ORCP on RNCL can be ignored during the active lightning period.     

Soil property variation mapping through data mining of soil category maps

Spatial information on soil properties is an important input to hydrological models. In current hydrological modelling practices, soil property information is often derived from soil category maps by the linking method in which a representative soil property value is linked to each soil polygon. Limited by the area‐class nature of soil category maps, the derived soil property variation is discontinuous and less detailed than high resolution digital terrain or remote sensing data. This research proposed dmSoil, a data‐mining‐based approach to derive continuous and spatially detailed soil property information from soil category maps. First, the soil–environment relationships are extracted through data mining of a soil map. The similarity of the soil at each location to different soil types in the soil map is then estimated using the mined relationships. Prediction of soil property values at each location is made by combining the similarities of the soil at that location to different soil types and the representative soil property values of these soil types. The new approach was applied in the Raffelson Watershed and Pleasant Valley in the Driftless Area of Wisconsin, United States to map soil A horizon texture (in both areas) and depth to soil C horizon (in Pleasant Valley). The property maps from the dmSoil approach capture the spatial gradation and details of soil properties better than those from the linking method. The new approach also shows consistent accuracy improvement at validation points. In addition to the improved performances, the inputs for the dmSoil approach are easy to prepare, and the approach itself is simple to deploy. It provides an effective way to derive better soil property information from soil category maps for hydrological modelling. Copyright © 2014 John Wiley & Sons, Ltd.