共查询到20条相似文献,搜索用时 171 毫秒
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文章主要介绍了激光平地机械化技术在天津地区的应用效果,通过技术介绍、效益分析、应用效果等方面充分论述了激光平地机械化技术. 相似文献
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介绍了生态农业技术的概念与特征,分析我国发展生态农业技术的必要性与发展情况,从生态农业接口技术、庭院生态农业技术、高效立体种养技术、农业水肥资源综合利用技术、能源综合开发利用技术等方面具体介绍了生态农业的技术,以期为生态农业的产业化发展提供参考。 相似文献
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我国油气储运相关技术研究新进展 总被引:4,自引:1,他引:3
系统梳理了我国油气储运相关技术的最新研究进展,提出了需要重点关注的其他热点问题。对于油气管道完整性和失效控制技术,强调了失效控制的理念及其与完整性管理相结合的必要性;对于热油管道流动保障技术,介绍了蜡沉积、原油流动特性及停输再启动等研究成果;对于冷热原油交替输送技术,介绍了热力影响因素和数值模拟等研究成果;对于多相混输技术,介绍了各种多相体系数值模拟的研究成果;对于成品油顺序输送混油控制技术,介绍了混油切割方法、混油质量分数模型及混油界面在线跟踪等研究成果;对于腐蚀控制技术,介绍了阴极保护系统数值模拟、杂散电流腐蚀、油流携水等研究成果;对于化学添加剂技术,介绍了复合纳米材料、油品减阻剂、天然气减阻剂等研究成果。 相似文献
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P2P技术与流媒体发展新趋势 总被引:1,自引:0,他引:1
首先介绍了P2P技术的基本概念、技术模式和典型的应用情况,然后对流媒体的特点、相关技术及应用进行了总结,最后对基于P2P平台的流媒体技术作了较全面的介绍与分析. 相似文献
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介绍了磁控溅射的基本原理,以及几种典型的磁控溅射镀膜技术(反应溅射、非平衡磁控溅射、等离子体加强磁控溅射技术);并介绍了利用磁控溅射技术制备钛合金耐冲蚀涂层的新进展。 相似文献
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Optimised Spatial Sampling Scheme for Soil Electriclal Conductivity Based on Variance Quad-Tree (VQT) Method 总被引:1,自引:0,他引:1
The acquisition of precise soil data representative of the entire survey area,is a critical issue for many treatments such as irrigation or fertilization in precision agriculture.The aim of this study was to investigate the spatial variability of soil bulk electrical conductivity(ECb)in a coastal saline field and design an optimized spatial sampling scheme of ECb based on a sampling design algorithm,the variance quad-tree(VQT)method.Soil ECb data were collected from the field at 20m interval in a regular grid scheme.The smooth contour map of the whole field was obtained by ordinary kriging interpolation,VQT algorithm was then used to split the smooth contour map into strata of different number desired,the sampling locations can be selected within each stratum in subsequent sampling.The result indicated that the probability of choosing representative sampling sites was increased significantly by using VQT method with the sampling number being greatly reduced compared to grid sampling design while retaining the same prediction accuracy.The advantage of the VQT method is that this scheme samples sparsely in fields where the spatial variability is relatively uniform and more intensive where the variability is large.Thus the sampling efficiency can be improved,hence facilitate an assessment methodology that can be applied in a rapid,practical and cost-effective manner. 相似文献
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Information on crop acreage is important for formulating national food polices and economic planning.Spatial sampling,a combination of traditional sampling methods and remote sensing and geographic information system(GIS)technology,provides an efficient way to estimate crop acreage at the regional scale.Traditional sampling methods require that the sampling units should be independent of each other,but in practice there is often spatial autocorrelation among crop acreage contained in the sampling units.In this study,using Dehui County in Jilin Province,China,as the study area,we used a thematic crop map derived from Systeme Probatoire d’Observation de la Terre(SPOT-5)imagery,cultivated land plots and digital elevation model data to explore the spatial autocorrelation characteristics among maize and rice acreage included in sampling units of different sizes,and analyzed the effects of different stratification criteria on the level of spatial autocorrelation of the two crop acreages within the sampling units.Moran’s I,a global spatial autocorrelation index,was used to evaluate the spatial autocorrelation among the two crop acreages in this study.The results showed that although the spatial autocorrelation level among maize and rice acreages within the sampling units generally decreased with increasing sampling unit size,there was still a significant spatial autocorrelation among the two crop acreages included in the sampling units(Moran’s I varied from 0.49 to 0.89),irrespective of the sampling unit size.When the sampling unit size was less than3 000 m,the stratification design that used crop planting intensity(CPI)as the stratification criterion,with a stratum number of 5 and a stratum interval of 20%decreased the spatial autocorrelation level to almost zero for the maize and rice area included in sampling units within each stratum.Therefore,the traditional sampling methods can be used to estimate the two crop acreages.Compared with CPI,there was still a strong spatial correlation among the two crop acreages included in the sampling units belonging to each stratum when cultivated land fragmentation and ground slope were used as stratification criterion.As far as the selection of stratification criteria and sampling unit size is concerned,this study provides a basis for formulating a reasonable spatial sampling scheme to estimate crop acreage. 相似文献
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庄晓山 《河北农业大学学报(农林教育版)》2006,8(1):77-78,82
介绍了学习型组织理论,探讨了“学习型组织”理论在高校管理上的现实意义和可行性,并重点从培养整体协作、改变办学风貌、促进改革以及实现可持续化发展等方面剖析了该理论在高校管理实践中的指导作用。 相似文献
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服务现代农业是农业院校理论与实践相结合的有效途径,河北农业大学走出的"太行山道路"曾经享誉全国,"六五"至今,与时俱进,实践内容不断丰富,促进了河北省农业与农村经济发展,表现出了一定的发展优势.对"太行山道路"实践历程进行总结,分析不同阶段其发展特点,得出"太行山道路"的可借鉴之经验并提出该实践模式的完善建议. 相似文献
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从区域可持续发展和工程评价的理论出发,采用层次分析和综合评价相结合的评价方法,即把种类繁多的指标引入模糊化理论方法进行综合评价.在总目标下,天保工程可持续发展能力评价通过多个层次的具体指标来完成--从目标层、状态层、能力层、指标层构建其评价指标体系,计算阿木尔林业局天保工程可持续发展能力的综合指数,对逐年的可持续发展能力展开评价和分析. 相似文献
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浅析团队角色理论的若干问题 总被引:1,自引:0,他引:1
团队角色理论是团队理论体系中的一个重要组成部分,具有较高的学术价值和实践意义。本文在对团队和团队角色基本理论研究概述的基础上,介绍了如何划分团队角色的类型,最后重点对团队的一般角色展开了分析。 相似文献
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目前的模拟信号数字化多是基于对模拟信号等时间间隔采样而得到数字信号来描述该信号特征,而实际应用中往往不能避免采样时钟的非均匀性;传统的频谱分析方法必然产生原理误差。引入随机延迟系统的知识,推导了起数字频谱的一般公式,分析了具有典型分布函数的随机采样情况。 相似文献
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