river birch

与river birch相关的网络例句 [注：此内容来源于网络，仅供参考]

A review of river management history in various countries is used in this thesis to discuss the future development trends of river management and the relationship between river health and river management.Based on the characterization and assessment of river health, Five components of stream condition are presented in this thesis to characterize river health: water quality, aquatic life, physical form, hydrology and streamside zone. It is obtained by comparing the methods and criteria that have been developed by others and reviewing the river assessment practices in various countries. Accounting for the features of urbanization region in plain river network, an indicator system for river health assessment which provides scores for 5 subindices and 17 indicators is established. With almost 200 stream reaches in Shanghai as objective of study and Liwa stream and Zhangjiabang Creek as case study, the application of river health assessment in the planning, baseline survey and post-project appraisal of river management is explored by collecting historical literature and field monitoring. Consequently, some suggestions to improve river management effectiveness are presented from the angle of river health.

本文回顾河流管理漫长历程并指出当前国际发展趋势，进而辨析河流健康状况与河流管理的关系；以河流健康状况的表征和评价为核心，通过对国外RIVPACS、AUSRIVAS、IBI、RCE、ISC等河流健康状况评价方法的分析和比较，以及对美国、英国、澳大利亚、南非等国家河流健康状况评价实践的总结，尝试从理化参数、生物指标、形态结构、水文特征、河岸带状况5个方面全面表征河流健康状况；结合中国东部平原河网地区自身特点，通过评价原则、评价指标、评价标准、评价权重确定等步骤，初步构建了包含河流水文、河流形态、河岸带状况、河流水质以及河流生物5个一级指标(共17个指标)的河流健康状况评价指标体系；在此基础上，采用资料收集与现场实测相结合的方法，以上海近200条中心河道为研究对象，以丽娃河和张家浜为典型案例，分别就河流健康状况在河流管理规划、现状评估以及后评估中的应用进行实证研究，并尝试探讨如何从这三个阶段利用河流健康状况评估改进河流管理的对策。

The paper sees Horton code as a primary characteristic value and generalizing condition of the river network, and selects, simplifies and generalizes river based on scale of before and after generalization,, The main contents of paper include:(1)Reviews generalization concept, arithmetic operators, methods, influence factor and frame of map generalization and design, analyze core theory of feature —oriented map generalization, discuss the main context and applicable method of river feature generalization(2) Summarizes natural form and spatial configuration characteristic of the river network, and describe the river network using digraph Paper mostly researches tree —like river, identifies the direction of river based on the angle of the main and secondary reach, and identifies the main river based on most length and predominant continuation of the flow direction along the major channel , then receives the grade of river by recursion and structuralize river network, builds hiberarchy rank system of river based on Horton coding(3)Designs the model of river network based on Horton code, and organizes the data of node, branch and river.

本论文把Horton编码作为水系网的一个主要特征值并以此作为综合条件，并根据综合前后的比例尺对水系网进行选取、化简和概括。论文的主要工作包括：(1)总结地图综合的概念、算子分解、实现方法、主要影响因素和总体设计框架，分析面向地理特征的制图综合的核心理论支撑，在此基础上讨论水系专题要素综合的主要内容和综合适用的方法。(2)总结水系网的自然形态和空间结构特征，用图论对水系网进行描述。以树状水系作为主要研究对象，依据树状水系的主支流交汇关系确定水系流向，依据水系中主流的长度最长和主流保持原有的流向趋势确定主流，按此递归得到河流的不同级别，对基于河段组织的水系网结构化，自动建立水系的Horton编码。(3)设计基于Horton码的水系网模型，对结点、河段、河流和河系的数据进行有效的组织。

The main reason why quarter-sawn board of Birch had smaller dry compressing shear strength than flat-sawn board of Birch in normal conditions was that Birch had different shear strength to the grain between quarter-sawn board and flat-sawn board. Meanwhile xylary rays in flat-sawn board were transversely cut and left a lot of pores in the flat-sawn board, so adhesive can enter these pores and turn into adhesive nail. While these pores provided a kind of tunnel for water, so cause this phenomenon that wet compressing shear strength of flat-sawn board of Birch was smaller than that of quarter-sawn board of Birch. The possible reason why quarter-sawn board of Oak had greater dry compressing shear strength than flat-sawn board of Oak in normal conditions was that ratio of springwood on quarter-sawn board and flat-sawn board was different.

造成柞木径切板的常态压缩剪切强度比弦切板的常态压缩剪切强度大的主要原因是，在径切板和弦切板上早材胶接的比例不同，径切板的胶合强度试件上早材胶接的比例相对少，而弦切板的胶合强度试件上早材胶接的比例比径切板的胶合强度试件上早材胶接的比例相对大，由于早晚材胶接过程中强度决定于早材，这部分胶接强度比较低，这就使得柞木径切板的常态压缩剪切强度比弦切板的大；同时在柞木弦径面胶接过程中由于实际胶接面积的不同也能造成弦径面上API胶粘剂与之形成的化学键的数量不同，这也是造成柞木径切板的常态压缩剪切强度比弦切板的大的原因之一。

与river birch相关的网络解释 [注：此内容来源于网络，仅供参考]

Its river birch and upland beech：她河边的桦树,高地的山毛榉

Its hills bent low within my reach, 她弯腰向我靠近的山岭, | Its river birch and upland beech 她河边的桦树,高地的山毛榉, | Were mine, of my own country, 统统属于我,属于我的祖国,亲爱的母亲.

river birch;black birch;water birch：水白桦

矮桦 dwarf birch, | 水白桦 river birch;black birch;water birch | 高原桦 mountain birch;fjeldbirch