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171.
系统介绍了双块式轨枕蒸养环节坑式与通道式两种生产工艺和管道布置,并对两种生产工艺在不同气候条件下的能耗进行了对比,以期促进蒸养生产工艺的应用.  相似文献   
172.
Results of breeding bird censuses in 1979 and 1980 were used to compare the relationships of both species and guilds to forest habitats in the White Mountains of New Hampshire. Several age classes of 11 forest cover types were studied: northern hard-woods (Fagus-Betula-Acer), spruce (Picea), spruce-fir (Picea-Abies), birth (Betula), swamp hardwoods (Acer-Pinus-Tsuga), pine (Pinus strobus andP. resinosa), balsam fir (Abies), aspen (Populus tremuloides andP. grandidentata), northern red oak (Quercus), oak-pine (Quercus-Pinus), and hemlock (Tsuga). All types were even-aged; only northern hardwoods had an additional uneven-aged condition. Forest cover types were also pooled to consider generalized habitats: hardwoods, mixed forest, or softwoods. Results of ordinations based on censuses of 74 bird species indicate that foraging guilds are more related to general cover types than are nesting substrate guilds, but bird species reflect habitat differences to a greater degree than do either guild scheme. Also, considerable overlap occurs in bird species distribution between hardwoods and mixed forests; softwoods show little overlap with other types. Discriminant function and classification analyses revealed that bird species composition can be used to correctly classify general forest habitats more accurately (83.8%) than either foraging (63.2%) or nesting substrate guilds (58.4%). These results indicate that, of the habitats studied, avian species compositions are more characteristic than are foraging or nesting substrate guild composition, which tend to be similar across forest habitats.  相似文献   
173.
Flood area and damage estimation in Zhejiang,China   总被引:1,自引:0,他引:1  
A GIS-based method to estimate flood area and damage is presented in this paper, which is oriented to developing countries like China, where labor is readily available for GIS data collecting, and tools such as, HEC-GeoRAS might not be readily available. At present local authorities in developing countries are often not predisposed to pay for commercial GIS platforms. To calculate flood area, two cases, non-source flood and source flood, are distinguished and a seed-spread algorithm suitable for source-flooding is described. The flood damage estimation is calculated in raster format by overlaying the flood area range with thematic maps and relating this to other socioeconomic data. Several measures used to improve the geometric accuracy and computing efficiency are presented. The management issues related to the application of this method, including the cost-effectiveness of approximate method in practice and supplementing two technical lines (self-programming and adopting commercial GIS software) to each other, are also discussed. The applications show that this approach has practical significance to flood fighting and control in developing countries like China.  相似文献   
174.
通过对松花江河冰的物理力学性能试验和松花江公路大桥桥墩的流冰动压力测量、桥面的脉动测量 ,依据国内外对冰 -结构相互作用的分析 ,提出了适合我国黑龙江冰情特点的春季流冰冰荷载的计算方法。  相似文献   
175.
176.
安全生产培训可为安全生产形势的稳定好转提供保障。本文结合安全生产工作实际,在不断摸索和总结培训工作经验的基础上,对如何做好地(市)、县(市)领导干部的安全生产培训工作,特别是培训的目的、方式和方法等方面有了更加清晰的认识。在此基础上对今后如何开展地(市)、县(市)领导干部的安全生产培训工作提出一些建议,如设置模块教学、理好传统教育与现代培训的关系、加大培训力度,扩大培训范围等方式和方法,以增强培训效果。  相似文献   
177.
在标准受限空间中,通过热态灭火实验对比分析了纯水细水雾和含氯化钴添加剂细水雾在不同添加荆浓度、工作压力下对煤油火的抑制效果.实验结果表明:含有氯化钴的细水雾比纯水细水雾具有更好的抑制效果.而细水雾的灭火时间并不是随着氯化钴的浓度变化而呈线性变化的,而是存在着一个最佳灭火浓度.实验表明:浓度为1.75%时的灭火效果最好.系统的工作压力也对细水雾的灭火性能有影响,在较高的工作压力下,细水雾的平均灭火时间较短.  相似文献   
178.
Circular economy (CE), with its basic principle of Reduce, Reuse, and Recycle, has been determined as the key strategy for the national development plan by the Chinese government. Given the economy-wide material flow analysis (EW-MFA) that leaves the inner flow of resource reutilisation unidentified, the reutilisation-extended EW-MFA is first introduced to evaluate and analyse the material input, solid waste generation, and reutilisation simultaneously. The total amount of comprehensive reutilisation (CR) is divided into three sub-flows, namely, reutilisation, recycle, and reuse. Thus, this model is used to investigate the resource CR in China from 2000 to 2010. China’s total amount of CR and its sub-flows, as well as the CR rate, remain to have a general upward trend. By the year 2010, about 60% of the overall solid waste generation had already been reutilised, and more than 20% of the total resource requirement was reutilised resource. Moreover, the growth patterns of the CR sub flows show different characteristics.Interpretations of resource reutilisation-related laws and regulations of CE and the corresponding policy suggestions are proposed based on the results.  相似文献   
179.
180.
河北省矿产资源行业生产资源配置效率的动态分析   总被引:1,自引:0,他引:1  
矿产资源行业作为国民经济的基础行业,一方面其产出支撑着国民经济的发展,另一方面其投入关乎不可再生资源的最优利用,是解决当前我国环境资源问题的关键环节。正是以矿产资源的最优利用为出发点,在国内矿产资源形势严峻和环渤海经济区经济发展急需大量矿产资源的背景下,选取河北省12个与矿产资源直接相关的行业,运用生产前沿面理论的非参数方法,定量计算并研究这12个行业从1997-2005年生产资源配置效率的理论值及其动态变化趋势,并通过宏观政策分析和生产资源配置效率结构分解分析,找出影响河北省矿产资源行业综合效率变化的因素,进而提出提高河北省矿产资源行业生产资源配置效率的措施。  相似文献   
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