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Study on the Occurrence and Epidemic Regularity and Region Division of Rice Blast in Nanchong City 被引量:1
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作者 彭昌家 白体坤 +2 位作者 丁攀 冯礼斌 杨宇衡 《Agricultural Science & Technology》 CAS 2016年第4期927-937,共11页
With the aim to improve the level of monitoring and warning as well as the comprehensive control of rice blast disease, and to feasibly reduce the disease threat in Nanchong City, the methods of GPS and GIS, systemati... With the aim to improve the level of monitoring and warning as well as the comprehensive control of rice blast disease, and to feasibly reduce the disease threat in Nanchong City, the methods of GPS and GIS, systematical monitoring and field survey, rice blast resistance identification, physiologic races of rice blast monitoring, and meteorological data analysis were performed to study the occurrence and epidemic region division, precise demarcation and occurrence and epidemic regularity of rice blast in Nanchong City. This study first completed the epidemic region division and precise demarcation; first clarified the initial affection(beginning period) locations, occurrence characteristics, epidemic trends and characteristics; explicated the existence of four epidemic peak periods of rice blast in the field, where the damage areas of first peak period played a decisive role during the blast epidemic years; in late May, the cumulative occurrence areas and annual occurrence areas presented higher positive correlation with the correlation coefficient of 0.817;and established a prediction model of occurrence areas per year based on the disease field rate at the end of boot stages and the diseased plant rate at dough stages. The results of investigation on the impact factors investigation of blast disease in Nanchong in recent years suggested that the internal causes were the decrease or loss of blast resistance of the rice cultivars, as well as the increase of physiological races with strong resistance to rice blast and the emergence of new virulent physiologic varieties; the external causes were suitable temperature, too much rainy, and sunlight shortage. Between 2010 and 2015, the short-term forecast accuracy for rice blast in Nanchong was up to 100%, and medium-and long-term forecast accuracy was also up to 98% and 95%, respectively, which increased by 5-15% than that before 1997, thereby making the control effect of rice blast in Nanchong increased by 15-30%. 展开更多
关键词 Rice Rice blast region division Occurrence characteristics Epidemic regularity Early warning level
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Localization Algorithm of Indoor Wi-Fi Access Points Based on Signal Strength Relative Relationship and Region Division 被引量:4
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作者 Wenyan Liu Xiangyang Luo +3 位作者 Yimin Liu Jianqiang Liu Minghao Liu Yun Q.Shi 《Computers, Materials & Continua》 SCIE EI 2018年第4期71-93,共23页
Precise localization techniques for indoor Wi-Fi access points(APs)have important application in the security inspection.However,due to the interference of environment factors such as multipath propagation and NLOS(No... Precise localization techniques for indoor Wi-Fi access points(APs)have important application in the security inspection.However,due to the interference of environment factors such as multipath propagation and NLOS(Non-Line-of-Sight),the existing methods for localization indoor Wi-Fi access points based on RSS ranging tend to have lower accuracy as the RSS(Received Signal Strength)is difficult to accurately measure.Therefore,the localization algorithm of indoor Wi-Fi access points based on the signal strength relative relationship and region division is proposed in this paper.The algorithm hierarchically divide the room where the target Wi-Fi AP is located,on the region division line,a modified signal collection device is used to measure RSS in two directions of each reference point.All RSS values are compared and the region where the RSS value has the relative largest signal strength is located as next candidate region.The location coordinate of the target Wi-Fi AP is obtained when the localization region of the target Wi-Fi AP is successively approximated until the candidate region is smaller than the accuracy threshold.There are 360 experiments carried out in this paper with 8 types of Wi-Fi APs including fixed APs and portable APs.The experimental results show that the average localization error of the proposed localization algorithm is 0.30 meters,and the minimum localization error is 0.16 meters,which is significantly higher than the localization accuracy of the existing typical indoor Wi-Fi access point localization methods. 展开更多
关键词 Wi-Fi access points indoor localization RSS signal strength relative relationship region division.
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Multi-dimensional and Multi-threshold Airframe Damage Region Division Method Based on Correlation Optimization
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作者 CAI Shuyu SHI Tao SHI Lizhong 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2021年第5期788-799,共12页
In order to obtain the image of airframe damage region and provide the input data for aircraft intelligent maintenance,a multi-dimensional and multi-threshold airframe damage region division method based on correlatio... In order to obtain the image of airframe damage region and provide the input data for aircraft intelligent maintenance,a multi-dimensional and multi-threshold airframe damage region division method based on correlation optimization is proposed.On the basis of airframe damage feature analysis,the multi-dimensional feature entropy is defined to realize the full fusion of multiple feature information of the image,and the division method is extended to multi-threshold to refine the damage division and reduce the impact of the damage adjacent region’s morphological changes on the division.Through the correlation parameter optimization algorithm,the problem of low efficiency of multi-dimensional multi-threshold division method is solved.Finally,the proposed method is compared and verified by instances of airframe damage image.The results show that compared with the traditional threshold division method,the damage region divided by the proposed method is complete and accurate,and the boundary is clear and coherent,which can effectively reduce the interference of many factors such as uneven luminance,chromaticity deviation,dirt attachment,image compression,and so on.The correlation optimization algorithm has high efficiency and stable convergence,and can meet the requirements of aircraft intelligent maintenance. 展开更多
关键词 airframe damage region division multi-dimensional feature entropy MULTI-THRESHOLD correlation optimization aircraft intelligent maintenance
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Optimal structural design for a certain near-space composite propeller of airship using adaptive region division blending model
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作者 Weigang AN Tianyu LIN Shigen WANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2024年第5期301-316,共16页
Near-space airship is a frontier and hotspot in current military research and development,and the near-space composite propeller is the key technology for its development.In order to obtain higher aerodynamic efficien... Near-space airship is a frontier and hotspot in current military research and development,and the near-space composite propeller is the key technology for its development.In order to obtain higher aerodynamic efficiency at an altitude of 22 km,a certain near-space composite propeller is designed as a long and slender aerodynamic shape with a 10 m diameter,which brings many challenges to the composite structure design.The initial design is obtained by the composite structure variable stiffness design method using based on fixed region division blending model.However,it weighs 23.142 kg,exceeding the required 20 kg.In order to meet the structural design requirements of the propeller,a variable stiffness design method using the adaptive region division blending model is proposed in this paper.Compared with the methods using the fixed region division blending model,this method optimizes region division,stacking thickness and stacking sequence in a single level,considering the coupling effect among them.Through a more refined region division,this method can provide a more optimal design for composite tapered structures.Additionally,to improve the efficiency of optimization subjected to manufacturing constraints,a hierarchical penalty function is proposed to quickly filter out the solutions that do not meet manufacturing constraints.The above methods combined with a Genetic Algorithm(GA)using specific encoding are adopted to optimize the near-space composite propeller.The optimal design of the structure weighs 18.831 kg,with all manufacturing constraints and all structural response constraints being satisfied.Compared with the initial design,the optimal design has a more refined region division,and achieves a weight reduction of 18.6%.This demonstrates that a refined region division can significantly improve the mechanical performance of the composite tapered structure. 展开更多
关键词 Structural optimization Composite tapered structure Genetic algorithm Adaptive region division Manufacturing constraint Near-space composite propeller
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Regional Division of Production and Development Strategy of Citrus in Hunan Province
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作者 杨玉 邓文 +3 位作者 李健权 王卫红 黄国林 张平 《Agricultural Science & Technology》 CAS 2012年第9期2029-2033,共5页
[Objective] The aim was to research regional division of citrus production and development strategies in Hunan Province. [Method] According to Rural Statisti- cal Yearbook in Hunan Province during 2002-2011, Citrus in... [Objective] The aim was to research regional division of citrus production and development strategies in Hunan Province. [Method] According to Rural Statisti- cal Yearbook in Hunan Province during 2002-2011, Citrus in Hunan province were divided into three production regions, namely, superior region, sub-superior and non- superior region. On the base of the divisions, the ecological regionalization and brand strategy, Optimization of regional distribution and developing strategy were proposed, with consideration of avoiding frozen zones, in this paper. [Result] Fresh and processing bases of mandarin orange (C.unshiu Marc), and specialty industries of seedless ponkan(C.reticulata Blanco), Bingtang orange (C.sinensis Osbeck Bing- tangcheng), Dayongjuhuaxinyou (Cgrandis (L.) Osbeck Dayongjuhuaxinyou) and An- jiangxiangyou (C.grandis (L.) Osbeck Anjiangxiangyou) should be constructed, where fresh fruit is dominant, supplemented by canned fruit and juice. Industry belt of sat- suma orange, fresh or processing food, is mainly built, for proportion of early and earlier ripe satsuma orange is over 50% of total yield in Xiangzhong citrus zone; in- dustry belt of excellent fresh navel orange and processing sweet orange should be highlighted in Xiangnan. [Conclusion] The research provides references for decision- making for governments, especially on optimization of citrus production regions and development of citrus industry. 展开更多
关键词 CITRUS regional division STRATEGY Hunan Province
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Airframe Damage Region Division Method Based on Structure Tensor Dynamic Operator
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作者 CAI SHUYU SHI LIZHONG 《Journal of Shanghai Jiaotong university(Science)》 EI 2022年第6期757-767,共11页
In order to improve the accuracy of damage region division and eliminate the interference of damage adjacent region,the airframe damage region division method based on the structure tensor dynamic operator is proposed... In order to improve the accuracy of damage region division and eliminate the interference of damage adjacent region,the airframe damage region division method based on the structure tensor dynamic operator is proposed in this paper.The structure tensor feature space is established to represent the local features of damage images.It makes different damage images have the same feature distribution,and transform varied damage region division into consistent process of feature space division.On this basis,the structure tensor dynamic operator generation method is designed.It integrates with bacteria foraging optimization algorithm improved by defining double fitness function and chemotaxis rules,in order to calculate the parameters of dynamic operator generation method and realize the structure tensor feature space division.And then the airframe damage region division is realized.The experimental results on different airframe structure damage images show that compared with traditional threshold division method,the proposed method can improve the division quality.The interference of damage adjacent region is eliminated.The information loss caused by over-segmentation is avoided.And it is efficient in operation,and consistent in process.It also has the applicability to different types of structural damage. 展开更多
关键词 airframe damage region division dynamic operator structure tensor feature distribution double fitness function intelligent maintenance
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Regional Geochemical Division—A Tool for Delineating Geochemical Block 被引量:3
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作者 Chen Ming Yan Guangsheng Department of Geology, China University of Geosciences, Beijing 100083 Fan Jizhang Li Jingchao Geomathematics Institute, Changchun University of Science and Technology, Changchun 130026 《Journal of Earth Science》 SCIE CAS CSCD 2000年第2期58-61,共4页
Regional geochemical division is a mapping technique to divide an area into slices where the associations between geochemical elements are relatively simple and uniform. The result of division is expressed on a 2 D ma... Regional geochemical division is a mapping technique to divide an area into slices where the associations between geochemical elements are relatively simple and uniform. The result of division is expressed on a 2 D map. The scheme of regional geochemical division includes non supervised pattern recognition, elementary statistics and factor analysis. A practical example in a gold prospecting area in Jilin, China, and the corresponding explanation are presented. Regional geochemical division is a basic approach to the delineation of the geochemical blocks as well. 展开更多
关键词 regional geochemical exploration regional geochemical division C transformation pattern RECOGNITION geochemical block association of elements.
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Climatic Characteristics of Hail Disaster and Division of Defense Region in Guizhou Province 被引量:3
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作者 WU Zhe-hong ZHAN Pei-gang 《Meteorological and Environmental Research》 CAS 2011年第8期63-66,共4页
[Objective] The aim was to study the climatic characteristics of hail disaster from 1984 to 2006 in Guizhou Province,China.[Method] Through statistical analysis,the climatic characteristics and disaster characteristic... [Objective] The aim was to study the climatic characteristics of hail disaster from 1984 to 2006 in Guizhou Province,China.[Method] Through statistical analysis,the climatic characteristics and disaster characteristics of hail from 1984 to 2006 in Guizhou Province were annalyzed and compared with previous results,then the classification standards of hail disaster were established,finally the defense zoning map of hail disaster in Guizhou Province was made.[Result] According to the statistical analysis on the historical data of hail disaster from 1984 to 2006,the frequency hail was 1 243 times in Guizhou in 23 years,that is,annual average frequency reached 54 times;annual average hailing days were 0.1-2.7 d in Guizhou Province,and the average frequency of hail was 3.8 times during each hail process;the frequency of hail was below 30 times in 52% of years and 30-80 times in 35% of years among 23 years.Hail could appear in the whole year,and 74% of hails occurred in spring,while winter had the fewest times.The results above were basically consistent with those of previous studies.Hail disaster mainly resulted in casualties and direct economic loss,and was divided into four grades according to direct economic loss,namely Grade I(extremely severe hail disaster),Grade II(severe hail disaster),Grade III(comparatively severe hail disaster) and Grade IV(medium hail disaster).The defense zoning map of hail disaster in Guizhou Province was made based on the frequency of hail and severe hail disaster,that is,the defense region at Grade I mainly distributed in Liupanshui City(in western Guizhou) and southern Guizhou;the defense region at Grade II was in the west,south and northeast of Guizhou Province,while the rest was at Grade III.[Conclusion] The study was of reference value for the defense of hail disaster in Guizhou Province. 展开更多
关键词 Hail disaster Climatic characteristics division of defense region Guizhou Province China
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Regional Clustering and Synchronization of Provincial Business Fluctuations in China 被引量:2
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作者 SONG Tao ZHENG Tingguo XIA Kai 《Chinese Geographical Science》 SCIE CSCD 2018年第4期571-583,共13页
In this article, we propose a novel, multilevel, dynamic factor model, to determine endogenously clustered regions for the investigation of regional clustering and synchronization of provincial business fluctuations i... In this article, we propose a novel, multilevel, dynamic factor model, to determine endogenously clustered regions for the investigation of regional clustering and synchronization of provincial business fluctuations in China. The parameter identification and model estimation was conducted using the Markov Chain Monte Carlo method. We then conducted an empirical study of the provincial business fluctuations in China(31 Chinese provinces are considered except Hong Kong, Macao, and Taiwan due to the data unavailability), which were sampled from January 2000 to December 2015. Our results indicated that these provinces could be clustered into four regions: leading, coincident, lagging, and overshooting. In comparison with traditional geographical divisions, this novel clustering into four regions enabled the regional business cycle synchronization to be more accurately captured. Within the four regional clusters it was possible to identify substantial heterogeneities among regional business cycle fluctuations, especially during the periods of the 2008 financial crisis and the ‘four-trillion economic stimulus plan'. 展开更多
关键词 regional division business cycle synchronization multilevel dynamic factor model variance decomposition
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川滇地区莫霍面深度和地壳厚度 被引量:13
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作者 徐志萍 王夫运 +2 位作者 姜磊 徐顺强 唐淋 《地震地质》 EI CSCD 北大核心 2018年第6期1318-1331,共14页
利用滑动平均法从川滇地区布格重力异常场分离出主要反映莫霍面起伏的低频布格重力异常场,将地震模型转换、并经过高程改正的密度模型作为初始模型,根据不同构造单元之间莫霍面上、下密度差不同,采用Parker法对低频布格重力异常场进行... 利用滑动平均法从川滇地区布格重力异常场分离出主要反映莫霍面起伏的低频布格重力异常场,将地震模型转换、并经过高程改正的密度模型作为初始模型,根据不同构造单元之间莫霍面上、下密度差不同,采用Parker法对低频布格重力异常场进行分区反演,得到了该区莫霍面深度和地壳厚度分布。结果显示:研究区西北部青藏块体从边缘向内部莫霍面深度和地壳厚度加深和增厚,分别为52~62km和54~66km;四川盆地莫霍面深度为38~42km;从南东向北西川滇菱形块体莫霍面深度为42~62km;红河断裂带以西的滇西地块,从南向北莫霍面深度为34~52km;龙门山、红河断裂带是莫霍面深度变化的梯度带;红河断裂带两侧自北向南莫霍面深度差异逐渐增加;攀枝花裂谷下方的莫霍面未发现明显隆起。川滇地区莫霍面深度分布明显受印度板块与欧亚板块碰撞及其向中南半岛侧向俯冲的制约。文中采用分区反演得到的莫霍面深度模型与已有的人工地震探测结果之间的均方差<1. 7km,同时通过与整体反演结果对比,表明在不同构造单元的地壳速度、密度结构存在明显差异的区域,以高分辨地震探测结果为约束,开展分区密度界面反演工作,可有效提高反演结果的可靠性。 展开更多
关键词 布格重力异常 川滇地区 分区密度界面反演 莫霍面深度
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贵州发展油茶种植业的区域划分 被引量:14
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作者 黄彩梅 刘海燕 +1 位作者 邹天才 周盛勇 《贵州农业科学》 CAS 北大核心 2011年第5期218-221,共4页
为科学规划油茶种植业的发展,通过集成贵州自然气候、土壤类型及地形特征等资料,结合油茶生物学特性及其适宜栽培的生态环境,对贵州油茶种植业发展的区域适应性进行了研究。结果表明:贵州油茶种植业发展可划分为3个优先发展栽培区,即黔... 为科学规划油茶种植业的发展,通过集成贵州自然气候、土壤类型及地形特征等资料,结合油茶生物学特性及其适宜栽培的生态环境,对贵州油茶种植业发展的区域适应性进行了研究。结果表明:贵州油茶种植业发展可划分为3个优先发展栽培区,即黔东南、黔西南和铜仁地区的大部分区域;1个较适宜栽培区,即黔中山原地区;1个次适宜栽培区域,即黔北及黔东北山原山地的部分地区;1个不适宜栽培区,黔西北中山山地丘陵地区由于海拔高、积温低、降雨量少,不适宜栽培油茶。 展开更多
关键词 油茶种植 产业发展 区域适应性 区域划分 贵州
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SAR Images Despeckling Based on Bayesian Estimation and Fuzzy Shrinkage in Wavelet Domains 被引量:3
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作者 吴艳 王霞 廖桂生 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2006年第4期326-333,共8页
An efficient despeclding algorithm is proposed based on stationary wavelet transform (SWT) for synthetic aperture radar (SAR) images. The statistical model of wavelet coefficients is analyzed and its performance i... An efficient despeclding algorithm is proposed based on stationary wavelet transform (SWT) for synthetic aperture radar (SAR) images. The statistical model of wavelet coefficients is analyzed and its performance is modeled with a mixture density of two zero-mean Gaussian distributions. A fuzzy shrinkage factor is derived based on the minimum mean square error (MMSE) criteria with Bayesian estimation. In the case above, the ideas of region division and fuzzy shrinkage arc adopted according to the interscale dependencies among wavelet coefficients. The noise-free wavelet coefficients are estimated accurately. Experimental results show that the algorithm proposed is superior to the refined Lee filter, wavelet soft thresbolding shrinkage and SWT shrinkage algorithms in terms of smoothing effects and edges preservation. 展开更多
关键词 SAR image despeclding fuzzy shrinkage factor MMSE region division. Bayesian estimation SWT
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面向城乡统筹的空间管制规划 被引量:16
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作者 金继晶 郑伯红 《现代城市研究》 北大核心 2009年第2期29-34,共6页
空间管制是城乡规划中的一项重要内容。文章调查了相关地区空间管制规划成果,通过统计分析,在归类对比的基础上提出城乡空间管制类型、结构与策略,以期使空间管制规划编制更加科学规范。
关键词 空间管制 分区结构 禁建区 限建区 适建区
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苏通大桥建设与南通区位的优势转化 被引量:5
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作者 丁宪浩 《南通师范学院学报(哲学社会科学版)》 2002年第1期53-57,共5页
苏通大桥的建设将从根本上改变南通的经济区位 ,将南通从上海强辐射圈的外缘拉入上海经济区的核心圈 ,使南通从交通网络的神经末梢升格为重要的交通枢纽。南通在区域分工中的角色应重新定位 ,通过积极发展特色经济 ,努力建成国际性物流... 苏通大桥的建设将从根本上改变南通的经济区位 ,将南通从上海强辐射圈的外缘拉入上海经济区的核心圈 ,使南通从交通网络的神经末梢升格为重要的交通枢纽。南通在区域分工中的角色应重新定位 ,通过积极发展特色经济 ,努力建成国际性物流仓储中心北翼分中心 ,具有国际竞争力的加工与贸易城市 ,面向国内国际大市场的绿色食品生产供应基地 ,上海等大都市的后花园。南通区位优势必须转化为经济优势 ,为此须调整发展思路 ,由自成体系转变为主动融合进上海板块 ,为优势转化确立观念基础 ;调整发展战略 ,由偏重于GNP的增长转变为切实实施可持续发展战略 ,为优势转化提供生态及技术基础 ;调整产业结构 ,由原有的支柱产业转向发展特色支柱产业 。 展开更多
关键词 苏通大桥 经济区位 区域分工 优势转化
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基于M型结构的企业商物分流 被引量:1
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作者 于强 《河北大学学报(哲学社会科学版)》 CSSCI 北大核心 2006年第4期52-57,共6页
地域部门化和顾客部门化的分部型企业组织,即M型结构,是目前我国大型企业普遍采取的基本组织形式。在此组织模式下推行销售物流与商流的分离,对于优化企业业务流程,提升企业竞争力具有重要意义。对比分析了M型结构下企业商物分流前后的... 地域部门化和顾客部门化的分部型企业组织,即M型结构,是目前我国大型企业普遍采取的基本组织形式。在此组织模式下推行销售物流与商流的分离,对于优化企业业务流程,提升企业竞争力具有重要意义。对比分析了M型结构下企业商物分流前后的业务模式特点及其在降低企业物流成本、提高服务水平等方面的重大改善,阐述了构建区域物流平台对企业商物分流的必要性及其构建原则,并就完善企业销售物流体系中的几个关键问题提出了意见建议。 展开更多
关键词 销售物流 M型结构 商物分流 区域物流平台
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中国自然灾害的分布与分区减灾对策 被引量:25
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作者 高庆华 《地学前缘》 EI CAS CSCD 2003年第U08期258-264,共7页
文中以中生代以来的地壳运动形成的纬向构造带、北东—北北东向构造带、北西—北北西向构造带、经向构造带所控制的山川地貌及相关的地质环境、气候环境和生态环境为基础 ,综述了中国重大自然灾害的空间分布格局 ,提出了自然灾害宏观分... 文中以中生代以来的地壳运动形成的纬向构造带、北东—北北东向构造带、北西—北北西向构造带、经向构造带所控制的山川地貌及相关的地质环境、气候环境和生态环境为基础 ,综述了中国重大自然灾害的空间分布格局 ,提出了自然灾害宏观分布之东西分区、南北分带的规律 ;从自然灾变、承灾体的密度、价值和脆弱性及社会减灾能力三重因素 ,分析揭示了中国自然灾害的直接损失具有东部和南部高、西部和北部低 ,相对损失呈现中南部高 ,向东、向西和向北都逐渐降低的空间展布特征和自然灾害在时间上呈波动增长的特点。基于中国自然灾害分布的地区差异性 ,文章强调在中国必须实行分区减灾 ,即 ,根据灾情和国情的不同划分减灾区 ,采取不同的减灾对策。基于此 ,文中将中国划分为城市减灾区、东部沿海减灾区、中部减灾区、西部减灾区和海洋减灾区 ,同时还分别提出了与各减灾区特点相适应的分区减灾对策。 展开更多
关键词 自然灾变 自然灾害 灾害分布 减灾区 分区减灾对策
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Multi-path routing algorithm in WSN using an improvedparticle swarm optimization 被引量:2
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作者 LI Hui-ling DU Yong-wen XU Ning 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2019年第4期361-368,共8页
To slove the problems of constrained energy and unbalanced load of wireless sensor network(WSN)nodes,a multipath load balancing routing algorithm based on neighborhood subspace cooperation is proposed.The algorithm ad... To slove the problems of constrained energy and unbalanced load of wireless sensor network(WSN)nodes,a multipath load balancing routing algorithm based on neighborhood subspace cooperation is proposed.The algorithm adopts the improved particle swarm optimization(PSO)algorithm,takes the shortest distance and minimum energy consumption as optimization target and divides the nodes in one-hop neighborhood near the base station area into different regions.Furthermore,the algorithm designs a fitness function to find the best node in each region as a relay node and forward the data in parallel through the different paths of the relay nodes.The simulation results show that the proposed algorithm can reduce energy consumption and average end-to-end delay,balance network load and prolong network lifetime effectively. 展开更多
关键词 wireless sensor network(WSN) improved particle swarm optimization(PSO) regional division MULTIPATH LOAD-BALANCING
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宁夏六盘山地区白垩纪地层环境演化研究 被引量:9
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作者 金学强 曹炜华 《宁夏工程技术》 CAS 2006年第1期1-3,共3页
为了探讨宁夏六盘山地区白垩纪地层演化的规律,进行了实际环境的地质调查.发现宁夏六盘山地区白垩纪地层广泛发育,自下而上划分为三桥组、和尚铺组、李洼峡组、马东山组、乃家河组;从沉积特征、地层层序、沉积相表明,六盘山群为一套冲积... 为了探讨宁夏六盘山地区白垩纪地层演化的规律,进行了实际环境的地质调查.发现宁夏六盘山地区白垩纪地层广泛发育,自下而上划分为三桥组、和尚铺组、李洼峡组、马东山组、乃家河组;从沉积特征、地层层序、沉积相表明,六盘山群为一套冲积扇-内陆湖泊相的碎屑岩、泥岩、碳酸盐岩夹膏岩沉积;从岩性组合、沉积特征及总体向上变细的垂向沉积序列看,六盘山群是在盆地持续下沉、湖水不断加深、沉积物供给较为充足的条件下形成的. 展开更多
关键词 六盘山地区 白垩纪 沉积相 沉积环境演化 层序特征
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Identifying and Mapping Wetland-based Ecotourism Areas in the First Meander of the Yellow River:Incorporating Tourist Preferences 被引量:2
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作者 张爱平 钟林生 +2 位作者 徐勇 党丽娟 周彬 《Journal of Resources and Ecology》 CSCD 2015年第1期21-29,共9页
We identified and mapped ecotourism areas in the First Meander of the Yellow River (FMYR) by incorporating tourist preferences, and regional division was also conducted. Considering wetland protection and local natu... We identified and mapped ecotourism areas in the First Meander of the Yellow River (FMYR) by incorporating tourist preferences, and regional division was also conducted. Considering wetland protection and local natural worship, we identiifed available ecotourism areas and used GIS to overlay six layers of the criteria to generate a suitability map of available areas. This process incorporated the opinions of 158 tourists to weight each criterion. Available areas were classiifed into ifve levels of suitability, with class I being the least suitable for ecotourism and class V being the most suitable. Distance from water area was found to be the most important criterion, and presence of forest to be the least important. The results show that a majority of the FMYR is class Ⅱ, Ⅲ or Ⅳ. FMYR was further divided into ifve sub-regions, and it is clear that the particular ecological characteristics and service functions of each sub-region warrant particular development. This study provides useful insights for tourism planners, local managers and visitors. 展开更多
关键词 ECOTOURISM suitable areas wetland protection regional division the First Meander of the Yelow River
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