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81.
82.
广州市制造业2007年气象服务效益评估   总被引:6,自引:5,他引:1  
根据典型单位选取原则,确定广船国际股份有限公司为广州市制造行业2007年气象服务效益评估典型单位。通过与典型单位专家共同设计气象服务效益评估计量方法(增加产值法),并对该单位气象服务效益进行详细的调查、研讨,得出第1阶段结果,气象服务的净效益值为1.479077亿元人民币。通过对广船在内的广州市制造业5个不同企业共25位专家,进行气象服务效益再调查,最终得出广州市制造业2007年气象服务效益为12.5亿元人民币。  相似文献   
83.
综述2009年1~3月广州地区的天气气候特征,指出各月广州气象短信采编的特色和重点,并将该段时间的气象短信内容按月串联汇总,用生动的短信文字清晰勾画出各月天气变化趋势.表明在正确的服务理念指引下,采编员们撰写出来的短信内容既丰富多彩,又不乏连贯性.  相似文献   
84.
SSQ-1型数字磁带记录水平摆式倾斜仪   总被引:2,自引:0,他引:2       下载免费PDF全文
SSQ-1型数字磁带记录水平摆式倾斜仪是测量地倾斜变化的高灵敏度仪器.它采用Zllner 双吊丝悬挂的石英水平摆接收地倾斜信号,通过电涡流传感器把摆端的位移变成电信号输出,由袖珍计算机采集数据并进行数字显示、数字打印及数字磁带记录,由笔绘记录连续监测仪器的工作情况.仪器的格值用胀盒————水银杯产生的已知倾角,通过计算机进行标定,格值为0.3——0.5m()/mV经台站试验,白家疃台东西向固体潮观测结果为r(O1):0.64900.0179,a(O1):-3.831.58r(K1):0.80490.0128,a(K1):1.400.90r(M2):0.66990.0040,a(M2):-0.270.34r(S2):0.73160.0075,a(S2):2.830.58r(M3):0.84970.0964,a(M3):1.616.51   相似文献   
85.
水下重力匹配导航作为辅助手段,能够有效克服惯性导航系统在水下长时间航行产生的误差积累.重力场的不规则性,使得不同海域重力场适配性存在差异,重力特征变化显著的海域匹配精度较高,反之精度较低.在适配性评价基础上,对导航路径进行规划有助于提高作业任务可行性,合理规避不利因素.本文采用重力异常标准差、粗糙度等特征参数对海域重力场适配性进行评价,形成重力场适配格网参考图,引入A*算法规划起始点和目标点间路径,达到了有效规避非适配区、提高航路设计合理性的目的.传统A*算法存在的问题是,规划路径折线较多、线路总弯曲度大,本文设计了一种改进方法,通过前后向对比分析,对单个路径节点逐个进行筛选过滤,有效减少了冗余航向调整,实现了路径的平滑优化.  相似文献   
86.
The Indian Sundarbans, a diversified coastal wetland on the southern fringe of the State of West Bengal, harbors a luxuriant biodiversity and acts as a potential refuge of living marine resources. Girdled with thick mangrove foliage, this estuarine delta system offers an excellent nursery ground for most of the brackishwater finfish and shellfish. Since supply of hatchery-produced tiger prawn seed (Penaeus monodon) is highly inadequate in West Bengal, the aquaculture farms of this region largely depend on the supply from natural resources. Being motivated by a regular cash income, the majority of coastal people from Sundarbans have adopted prawn seed collection as their profession almost throughout the year as an important source of earning. The users are neither trained nor guided at any stage from collection to marketing and are fully dependent on traditional methods. They first sort out the tiger prawn seeds (mainly the postlarval stage PL 20) accounting only 0.25-0.27% of the total catch and thereafter the major portion of the haul are thrown away on the beach flats or the tidal mudflats. This wasted by-catch contains the juveniles of economic and uneconomic varieties of finfish and shellfish along with a bulk of holoplankters and meroplankters (non-target species). This practice causes several ecological and occupational consequences, namely, (i) the huge destruction of the pelagic biota that can lead to severe stock depletion as well as hamper the energy transference through the marine ecosystem food webs; (ii) constant dragging of nets along the coast and tidal creeks paves the way for soil erosion, uprooting the mangrove seedlings and saltmarsh vegetation; (iii) the water quality is deteriorating in the catchment areas due to mud erosion and (iv) due to constant contact with the seawater, the collectors are affected with waterborne diseases, skin infections, reproductive tract disease in women and many other contagious diseases.This paper, in addition to identifying the challenge to environmental quality and resource abundance, emphasizes the need for grass-root public education so that local people come to understand, support and implement sustainable resource conservation and environmental protection activities now and in the future. As a follow-up course of action, the authors have initiated a general awareness program for developing consciousness among the coastal people regarding proper use of natural resources. Initiatives are taken for educating coastal people by holding workshops and seminars with the use of educational resource materials. Exclusive awareness camps and grass root level training for coastal people are also being proposed as a future course of action by means of exhibitions, audiovisuals etc. It is proposed that local government bodies come forward to mitigate this problem with scientific and rational approaches and to take proper actions towards conservation.  相似文献   
87.
88.
地应力与巷道布置关系的理论研究   总被引:4,自引:0,他引:4  
初始地应力是地下工程围岩稳定与支护结构设计的一个基本参数。介绍了地应力计算原理 ,并根据矿井实测地应力资料 ,分析了初始地应力场与巷道布置及巷道破坏形式的关系。为今后选择巷道掘进方向和改进巷道支护方案提供了依据。  相似文献   
89.
Generating MODFLOW grids from boundary representation solid models   总被引:3,自引:0,他引:3  
Complex stratigraphy can be difficult to simulate in MODFLOW models. MODFLOW uses a structured grid that requires that each grid layer be continuous throughout the model domain. This makes it difficult to explicitly represent common features such as pinchouts and embedded seams in a MODFLOW model. In this paper, we describe a method for automatically generating MODFLOW-compatible grids from boundary-representation solid models. Solid models are data structures developed originally for computer-aided design applications that define the geometry of three-dimensional objects. Solid models can be used to represent arbitrarily complex stratigraphy. The elevations defined by the solids are then extracted from the solids in a manner that preserves the continuous-layer requirement imposed by MODFLOW. Two basic approaches are described: The first method adjusts the MODFLOW grid dimensions (layer elevations) to fit the solid model boundaries, and the second method creates a regular MODFLOW grid and adjusts the material properties to match the changes in stratigraphy. One of the main benefits of using solid models to define stratigraphy for MODFLOW models is that it provides a grid-independent definition of the layer elevations that can be used to immediately re-create the MODFLOW grid geometry after any change to the grid resolution.  相似文献   
90.
应用水文地质调查法、地下水动力学法和数理统计法对黄沙坪铅锌矿中深部矿床水文地质特征进行了深入的研究,认为该矿床水文地质类型为水文地质条件中等偏简单,以溶蚀裂隙为主的直接顶板型岩溶充水矿床。  相似文献   
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