辽宁省凤城市林家金矿地质特征及成因探讨

林家金矿的赋矿地层为早元古界辽河群变质岩系,矿体形态产状严格受断裂控制,呈脉状、扁豆状产出,沿走向呈舒缓的波状,局部有膨缩变化,矿床成因类型为岩浆期后中低温热液充填交代型金矿床。     

基于ENVI-met模式的城市近地表气温模拟与分析-以南京市部分区域为例

城市不同下垫面与建筑物空间形态对近地表气温等微气候要素产生了重要影响。开展城市气温时空变化模拟与影响因素分析,对于城市热环境评价与城市规划具有重要意义。论文基于高空间分辨率Geoeye-1立体影像,在建筑物高度、下垫面覆盖类型信息提取的基础上,选择南京一中、光华东街、玄武湖、头陀岭4个区域,采用ENVI-met微气候模式,以城市基本气象站南京站的实时气象数据作为背景气象场,模拟不同区域近地表气温的时空分布特征,并利用区域自动气象站观测数据进行精度检验。结果表明:在时间变化上,ENVI-met模拟气温与实测值之间吻合程度较高;在空间分布上,南京一中与光华东街区域气温时空分布规律总体相似,但城市空间形态的差异使得局部区域气温变化不同,玄武湖区域气温由陆地中心向外围呈递减趋势,而头陀岭地形复杂多变,白天气温变化剧烈,夜间空间变化较小。     

基于形态分割的高分辨率遥感影像道路提取

基于灰度形态学,提出一种从高分辨率遥感图像提取道路网络的方法.首先利用灰度形态特征对遥感影像进行分割,进而得到基本的道路网络轮廓.然后在此基础上,利用线段特征匹配方法提取道路网络.提出的方法能适应于从道路和背景区别不很清楚的遥感图像中提取道路.实验结果也表明,本文方法能有效地从遥感影像中提取道路网络.     

基于SPOT遥感影像的九段沙潮沟信息提取及分维研究

以长江口九段沙为研究区, 应用灰度形态学提取了九段沙湿地的潮沟信息, 并对提取出的潮沟信息分区域采用网格法进行了分维研究, 得出了九段沙不同区域潮沟的分维值, 并对分维值进行了比较与分析。比较发现, 九段沙不同区域的分维值, 上沙最大, 下沙次之, 中沙最小。而在不同区域的不同岸段中, 处于上沙北部沿岸的潮沟分维值大于上沙其它地区; 处于中沙、下沙西北-东南沿岸的潮沟分维值分别大于中沙、下沙的其它地区。这主要与它们所处地理位置水动力条件不同有关。另外也计算了九段沙南岸与北岸的分维值, 发现南岸的分维值要大于北岸, 这与其发育时间、水动力条件和长江口深水航道工程等有一定联系。     

Morphological analysis and recognition of scanned raster nautical chart

In current practice in the development of hydrographic information systems, the automatic acquisition of spatial data has been considered to be very difficult. One of the key problems is recognition and correct separation of a feature from a complex graphic background. For these problems, this article presents a new concept of graph subsets to describe graph structures and composition rules of symbols in nautical charts. Based on this concept, morphological methods and operations in graph theory are unified into a coherent mathematical framework specially designed for analysis and recognition of binary chart images. In particular, an experimental system composed of feature extraction, symbol recognition, geometric reasoning, and intelligent control is developed for automatic digitization of nautical charts.     

The fauna and chemical composition of some athalassic saline waters in New Zealand

The fauna and chemical composition of two athalassic saline waters located near central Otago are discussed, and available rainfall and evaporation data for the region summarised. One water (dominated by Na and C1) had a salinity of 15‰ and contained the rotifer Brachionus plicatilis, the copepod Microcyclops monacanthus, the ostracod Diacypris, and larvae of the dipteran Ephydrella The second water (dominated by Na and HCO₃) had a salinity of 6‰ and contained larvae of Ephydrella (adults of E. novaezealandiae occurred on the shore), and the hemipterans Sigara arguta, Anisops wakefieldi and Anisops assimilis The relationship between Microcyclops monacanthus and M. arnaudi (an Australian species), and the basis of their current taxonomic separation is discussed in some detail.

At a minimum, the faunas of Australian and New Zealand athalassic saline waters have in common the following distinctive (non‐cosmopolitan) forms: Ephydrella, Diacypris, and two closely related halobiont species of Microcyclops     

Studies on twelve common bivalve larvae,with notes on bivalve spawning seasons in New Zealand

Twelve common bivalve larvae occurring in the plankton from the Bay of Islands (35°15'S, 174°10'E), Wellington Harbour (41°16'S, 174°51'E), and off Raumati Beach (40°56'S, 174°58'E), New Zealand, during 1970–72 are described and, wherever possible, provisionally identified. The seasonal occurrences of these larvae in the plankton are also described. Information on the spawning cycles of some New Zealand adult bivalves is reviewed; although some species have a short (4 months or less) spawning season, for most it is much longer, possibly with ‘trickle’ spawning through several months of the year.     

A new species of Plaxiphora (Mollusca: Polyplacophora) from southern New Zealand

Plaxiphora boydeni n.sp. from wave‐exposed rocky shores of southern New Zealand is described and illustrated. This is the first published record of the genus from the New Zealand mainland. P. boydeni is readily distinguished from the 2 other New Zealand species of the genus, which occur in the subantarctic region, by the absence of bristle‐tufts on the girdle.     

Critical depths for passage in braided rivers,Canterbury, New Zealand

Riffles and points of divergence of branch channels in braided rivers are critical controls upon passage of fish and recreational boats because they are points at which depths are at a minimum. Depths on randomly selected riffles were measured in braided reaches of the Ashley, Hurunui, and Rakaia Rivers and related to discharge; minimum depths encountered in extended reaches of these rivers at a range of flows have also been measured. The data can be used to predict minimum available passage depths at a specified flow, or conversely, to predict the discharge required to maintain a specified minimum passage depth. However, presently available estimates of critical minimum depths required for various instream uses (migration of salmonids, jetboating) appear excessively conservative, and minimum depth requirements must be more accurately determined before instream flow needs can be properly assessed.