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1.
作者根据雹云等强对流天气的雷达回波参数的数量特征，应用Ｆｉｓｈｅｒ判别分析法，对待识别的强对流天气样本云作出雹云和雷雨云的定性分类判别。用该方法对成都市１９８２～１９９０年的１７３个雹云和雷雨云样本回波资料建模，并对１９９０年的１３个试报样本进行检验。其判别结果与主分量分析法判别结果比较表明该方法用于雹云识别是适合的。 相似文献
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基于Fisher判别分析法的岩溶塌陷预测 总被引：2，自引：0，他引：2
为了更准确地预测岩溶塌陷,基于Fisher判别分析法,首先选择内聚力、内摩擦角、覆盖层厚度、覆盖层厚度减高水位埋深、覆盖层厚度减低水位埋深5个最主要的影响因素作为判别因子;接着以桂林市20组岩溶塌陷案例为学习样本进行计算,建立相应的Fisher线性判别函数;然后利用回代估计法对上述20组样本的预测结果进行逐一检验,其正确率为100%;随后将上述预测结果与前人运用逐步判别、神经网络判别等方法得到的结果进行比较分析,认为Fisher判别分析法具有不需进行模型和参数的选择以及不受人为因素的影响等优点;最后将建立的Fisher线性判别函数用于另外的10组实际案例进行预测分析,预测结果与实际情况完全吻合。结果表明:用Fisher判别分析法进行岩溶塌陷预测,简易方便,正确率高,实用性好;该方法是岩溶塌陷预测的一种新方法。 相似文献
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本文运用差分法、灰色动态滤波、有限富氏级数拟合、契比雪夫多项式拟合等四种方法，同时对１９８４年５月２１日南黄海Ｍｓ６．２级和１９８７年２月１７日射阳Ｍｓ５．１级地震前后时段内的数据资料进行处理，以莱以特准则和格罗布斯准则对处理后的残差序列进行异常超始时间的判别，并对比和综合分析。两种准则相比较，格氏判别在数学上更加严密，结果更为可信。初步研究表明，中强震在震级较高的情况下，用两种准则判别的结果比较接近，而在震级较低的情况下两者判别结果有差异。综合判别结果与总结本地区中强震震例给出的相关经验公式之计算结果相近。 相似文献
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阐述了剪切波速法判别饱和砂土液化的原理,结合武汉地区某工程实例,对场地内埋深超越"规范法"适用范围的砂层进行液化判别,确定场地的临界液化深度。通过与室内动三轴试验的对比得出,2种方法的液化判别结果及确定的临界液化深度均吻合较好,验证了以剪切波速为指标的液化评估方法的可行性。 相似文献
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文章在梧州防洪堤地基勘探试验资料基础上,根据国内外一些规范判别标准,优选了几种简易、具代表性的判别方法,对地基土渗透变形及地震液化可能性进行计算分析,取得了较好一致性。 相似文献
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城市土地资源集约利用程度判别指标体系的构建及依据 总被引：2，自引：1，他引：1
本文利用层次分析法,将各指标因子划分为目标层、准则层和指标层3个层次,采用Saaty1～9标度法计算各指标因子权重,并针对不同空间层次和不同土地用途建立城市土地资源集约利用程度判别指标体系,以期实现对城市土地资源集约利用程度的量化评价。研究发现,宏观层次判别指标体系主要侧重土地经济效益。中观层次判别指标体系中,商服用地主要侧重土地的经济效益;住宅用地主要侧重土地的使用强度;工业用地主要侧重土地的投入强度。微观层次因土地用途和土地级别不同,判别结果会有很大差异。 相似文献
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玄武岩类形成的大地构造环境Ta、Hf、Th、La、Zr、Nb比值对比判别 总被引：3，自引：0，他引：3
玄武质岩浆见于板块构造演化的全过程和各个重要阶段,是所有火成岩中最主要的构造地球化学指示剂,因此,玄武岩类相关元素图解和比值成为研究火成岩成岩作用和形成构造环境判别的首选对象。Ta、Hf、Th、La、Zr、Nb都是高场强元素和较强不相容元素,由于地球化学性质的相似性和在玄武岩类成岩过程中的规律性变化,所以它们是玄武岩类成因研究和构造环境判别图解中使用频率最高的元素,而且两两元素含量之间的比值能较好地区分其形成时的构造环境。在前人发明的玄武岩类Th/Hf-Ta/Hf、Th/Zr-Nb/Zr及La/Zr-Nb/Zr双对数判别图解基础上,运用这6个元素两两组对的Ta/Hf、Th/Ta、Th/Hf、Nb/Zr、Th/Nb、La/Nb值,建立比值判别表,极好地区分了几乎最常见的各种构造环境中有关的玄武岩类。该比值判别表是对双对数判别图解的极好补充。 相似文献
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在测井储层评价中准确识别储层流体性质是其关键。但当储层测井响应特征并不特别明显时,只采用常规测井识别方法不易准确区分气、水层。为此,综合常规测井和试油资料,选取反映气、水层特点的特征参数建立划分气层、气水同层及水层的模糊综合判别因素,利用Logistic统计法确定隶属函数曲线,即以Logistic函数为激活函数,利用模糊统计法确定隶属函数曲线;然后结合权重集建立了模糊综合判别模型对流体的性质进行模糊判别,经检验该方法能较准确地判别出水层、气水同层和气层。 相似文献
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《广东海洋大学学报》2020,(2)
【目的】探讨矢耳石地标法在笛鲷种内及种间中的判别作用。【方法】利用2017年购自广西北海、海南文昌、广东阳江的87尾红鳍笛鲷(Lutjanus erythropterus)和76尾紫红笛鲷(Lutjanus argentimaculatus)成鱼的矢耳石样本,基于地标点法分析耳石的形态差异,运用判别分析检验耳石形态差异在2种笛鲷的种间和同种不同群体间的判别功效。【结果】位于听沟前中部交叉点的两个地标点10、11贡献较大,解释了耳石形态变异的64.88%～65.85%,表明两种笛鲷耳石形态的种间差异和种内群体差异主要集中于听沟前中部。基于耳石形态的地标点方法对2种笛鲷的种间判别成功率为97.4%和100.0%;红鳍笛鲷和紫红笛鲷的种内不同群体判别成功率分别为85.7%、83.3%、80.0%和94.1%、78.1%、81.5%。【结论】矢耳石地标点法可作为2种笛鲷种间和种内判别的有效工具。 相似文献
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详细介绍了一种确定三维网中相对稳定点组的方法。依据一组点间的几何关系是否保持不变可以判别这一组点是否相对稳定。文中阐述了该方法的实施步骤,且给出了一个实例,证明了方法的有效性。该方法还可用来判别某些ＧＰＳ点是否位于同一构造块体上 相似文献
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基于DEM提取坡谱信息的不确定性 总被引：3，自引：1，他引：2
坡谱是黄土高原地学分析新方法、新思路的探索。本文基于坡谱不确定性的概念及其过程分布模型的论述,以陕北黄土高原国家1∶10000和1∶50000DEM数据为基本信息源,分析了坡谱不确定性的产生原因、主要影响因素与影响规律,阐述了坡谱提取与应用中应注意的主要问题,为正确应用坡谱进行地学分析提供重要依据。 相似文献
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State and Development： Changes in Livelihood Strategies in Garhwal with Special Reference to Ecotourism in the Gangotri Region 总被引：1，自引：0，他引：1
GitanjaliChaturvedi 《山地科学学报》2004,1(3):223-238
The object of the paper is to provide an insight into the changes in livelihood strategies of the people in the Garhwal Himalayas over time. From sustaining an economy based on transit trade and subsistence agriculture, there has been a shift towards tourism in recent times. This shift has been due to the tradition of pilgrimage to the higher reaches and also due to promotion by the state by developing infrastructure and providing incentives. The paper is divided into four parts. In the first part, the policies of the colonial state and the events leading to the destruction of forests and the impoverishment of the self-sustaining semi-pastoral economy in the Garhwal Himalayas are outlined. It is argued that the destruction of forests and subsequently, the economy of the Himalayas were directly responsible for the large-scale migration to the plains. This also led to further exploitation of forests by the people who were unfamiliar with any other form of livelihood. The paper also discusses the policies of the newly independent Indian state and sees them as an extension of the British policy of large-scale exploitation of Himalayan forests for the purpose of development and economic growth. In the third section, the growth of ecotourism as a direct outcome of the orocess of deforestation and as resulting from the need of society to conserve and yet to earn a livelihood is discussed. The case study of the Gangotrir egion examines the dilemma faced by the people of Garhwal in sustaining their livelihood, income or the development in the area. In addition, tourism has fostered monopolies of groups external to the region thereby contributing neither to the income or the development in the area. In addition, there is an added threat to the environment-deforestation, and erosion-a direct outcome of increased and unplanned tourism. Such problems demand state intervention and management of t.ourism. The conclusion to the paper asserts that in order that the requirements of the society to progress and to sustain itself in its natural habitat are not compromised, it is essential to increase the process of democratization by strengthening local structures and by vesting the community with the autonomy to determine its future. The paper therefore argues that ecotourism in the Himalayas undertaken without local involvement is not desirable. The constant need for local monitoring of external agencies or even of the State‘s participation and the need for re-evaluation of environmental standards are cumbersome details that add to the costs of promoting low-impact tourism. To be viable, ecotourism should be community based and the needs of the community, their ideas of conservation should be given prime importance and local community must be encouraged to review the standards governing conservation. Local structures should thus receive patronage and promotion, so that ecotourism becomes a dynamic facet of economic development. 相似文献
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长兴水口顾渚山风景区的紫笋茶,是闻名国内外的优质名茶。本文在实地调查的基础上,分析了紫笋茶优异的品质与地质环境背景条件的相关性。特定的地质背景条件,首先造就了一个避风向阳、雨量充沛的小气候环境;特定的泥盆系与花岗岩类浸入岩的地层背景所形成的土壤,为茶树生长提供了大量的营养物质,特别是有益的微量元素对提高茶叶品质起到了重要作用;同时这一特定的背景条件下,形成了对茶树生长有利的酸性土壤。特定的水文地质背景条件．又提供了充足的水份,还补充了茶树生长所必需的营养物质。通过对环境背景条件的分析,最终提出了长兴县茶叶发展的方向。 相似文献
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当前许多生产企业的生产设备已非常陈旧 ,然而这些企业却不愿更新 ,原因之一就是因为在大多数企业只被允许采用直线法等一般的折旧方法对固定资产进行计提折旧 ,使得企业在固定资产方面的投资收回较慢 ,大大限制了企业在固定资产方面投资的积极性。针对这一现状 ,文章从“实行加速折旧不会减少国家财政收入”入手 ,论述了实行加速折旧的可行性 ,从 3个方面论述了实行加速折旧的必要性。认为扩大加速折旧企业的范围已切实可行。 相似文献
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Results of a series of experiments(on the adsorption of divalent metal ions by dried alginic acid, Na and Ca alginates of different composition and block structure) conducted in this systematic study of the effects of the composition and structure of alginates on the static adsorption equilibrium of divalent metal ions indicate that the properties of alginate adsorption to divalent metal ions are highly different, depending not only on the cations used, but also on the form and structure of the alginates. There is close correlation between the adsorption properties and the structure of the alginates. The selectivity coefficient of Na alginate for Cd-Sr ion exchange tends to increase with the increase of the M/G ratio in alginate, whereas the adsorption capacity of Ca alginate for Cu~(2+) ion decrease with the increase of the G-block or the average length of the G-block ((?)_G) and the total adsorption capacity of alginic acid is found to vary in the same order as the F_(MM)(diad frequency) in alginate in 相似文献
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对象间的关联关系可视化主要是通过图的连边进行表达的,但是对象间的关联关系纷繁复杂,大量的连边交错会造成严重的视觉混乱,图布局和边捆绑都是解决复杂连边造成的视觉混乱问题的有效途径,然而某些节点的地理位置具有实际的含义,只能通过边捆绑方法来减少幅面载负量,进而揭示图的潜在关联规律。以往的边捆绑算法是在边的两端节点固定的前提下,调整边的中间控制点的位置,这样会使得大量边被聚集在一起,不仅会造成二次视觉混乱,且难以在节点级别揭示图的关联趋势。针对这一问题,本文提出了一种以节点为中心的关系边聚类与可视化算法。首先使用方向聚类算法实现隶属于同一个节点的连边的聚类,本文提出的方向聚类方法速度约是K-means算法的13倍,约是DBSCAN算法的6倍,然后对各个连边实现控制点的内插,在此基础上使用FR模型使得控制点位移,并通过弯曲度控制防止“过度弯曲”情况的出现,最后调整边的透明度,使得可视化的结果突出显示边靠近端点处的部分。实验结果表明,本文NCEB算法的幅面载负量L和中点距离变化量△d的约为FDEB算法的二分之一,证明本文算法可以将捆绑位置从边的中间部位移动到节点端,不仅解决了传统边捆绑算法造成的二次视觉混乱问题,而且使得节点周围的连边分布趋势清晰可读,且视觉负载大大降低,有效减少了视觉误差和信息误判。 相似文献
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Gold and tin of fluid-magmatic systems： causes of combination-separation of concentration elements 
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下载免费PDF全文 The aim of the investigation is to reveal possible causes of isolation and co-occurrence of the economically significant concentrations of gold and tin. Comparative analysis of the different-rank factors that influenced migration and concentration of these elements show that different geochemical properties of Au and Sn are responsible for isolation of their big concentrations giving rise to independent metallogenic provinces, zones, and ore nodes. These differences resulted in individualization of the element migration ways to the level of ore concentration within the fluid-magmatic columns. Three main factors influenced the Au and Sn migration activity: different patterns of metal connection with the melt structure, different relation with oxygen, and different relation with other strong oxidizers. By the moment when ore-bearing fluid became isolated from magmas, the metallogenic signature of the melts, contrasting in redox-potential, had already been defined that was confirmed by the fact that tin ores associate predominantly with the granitoids of ilmenite series and gold ores with those of magnetite series. The fluid-magmatic systemswith an intermediate degree of the melt reduction-oxidation may be considered the potential producers of the combined metal concentrations. In these cases, the combined concentrating of tin and gold is plagued by an opposite direction of the oxidation-reduction reactions when their most common minerals are formed: the main migration form of Sn+2 must be oxidized (with cassiterite portioning) , and the forms of Au+ or Au+3 must be reduced (with native gold portioning) . Probably, because of this the combined tin and gold concentrations are dominated by one of the metals with a tendency of accumulation in different-stage mineral complexes. 相似文献
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从小岩体成大矿和岩浆通道成矿理论的提出、发展、完善及其主要成矿控制因素展开探讨,结合典型矿床实例,指出这两种理论在勘查实践中的贡献和应用价值,并比较其异同点。小岩体成大矿与岩浆通道成矿理论的主要区别在于:小岩体成大矿理论中岩浆管道与岩浆通道成矿理论并非同一概念;深部熔离预富集是前者的主要控制因素;前者是硫化物深部熔离-脉冲式贯入占主导,而后者是硫化物就地熔离-局部聚集为主;在硫化物熔离机制方面,后者要求外来硫的加入是必需条件,而前者认为外来硫的加入并非不可或缺,在岩浆深部就可以发生硫化物不混溶作用;在成矿物质聚集方式上,后者认为含矿岩浆分凝和上侵是连续过程,而前者则强调岩(矿)浆上侵是脉动式过程。在找矿实践过程中要重视小岩体,并注重含矿小岩体的下盘和岩浆上升的管道位置,这些地区是扩大区域找矿前景、增加资源储量最具潜力的部位。 相似文献
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黄土高原"千沟万壑"的地貌形态,在多尺度空间下表现出显著自相似性,具有"局部无规则,宏观有规律"的纹理特征.目前,黄土高原地形纹理的提取方法及应用已经得到初步发展,但依然缺乏在理论层面的框架体系.本文在已有学者研究成果的基础上,限定黄土高原为研究范围,明确提出黄土高原地形纹理的概念模型,即内涵、特征、分类及表达.将内涵... 相似文献