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迈克耳孙干涉仪测量He-Ne激光波长的最佳测量区间 被引量:4
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作者 申文高 《物理实验》 1994年第5期235-236,230,共3页
迈克耳孙干涉仪测量He-Ne激光波长的最佳测量区间申文高(湖南大学物理系410012)用迈克耳孙于涉仪的点光源非定域干涉测量He—Ne激光波长时,当两反射镜间隔之差很小时或很大时都会带来误差,误差值一般偏大.木文通过... 迈克耳孙干涉仪测量He-Ne激光波长的最佳测量区间申文高(湖南大学物理系410012)用迈克耳孙于涉仪的点光源非定域干涉测量He—Ne激光波长时,当两反射镜间隔之差很小时或很大时都会带来误差,误差值一般偏大.木文通过分析,给出了最佳的测量区间.测波长... 展开更多
关键词 迈克耳孙干涉仪 氦-氖激光 波长 最佳测量区间
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欧姆表测量区间的选择与误差特性
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作者 刘玉明 《内蒙古民族大学学报(自然科学版)》 1995年第2期154-156,162,共4页
本文通过分析得出了用欧姆表测量电阻的误差范围,以及倍进率为10的欧姆表合理的测量区间为3R_0──R_0。
关键词 欧姆表 误差 测量区间
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浅谈动圈仪表的最佳测量区间
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作者 朱立吾 《计量与测试技术》 2000年第3期30-30,共1页
本文提出了确定动圈式仪表最佳测量区间的方法 ,是采用对已知仪表的测量函数关系式以及它的误差传递公式取极小值来求得。举例论证加以说明。作者告诉人们只有正确掌握仪表的最佳测量区间 ,才能获得高精确度的测量结果。
关键词 测量函数关系式 最佳测量区间 动圈式仪表
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地铁盾构区间施工测量技术研究 被引量:16
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作者 边大勇 卢小平 +1 位作者 李永强 张光胜 《测绘通报》 CSCD 北大核心 2011年第4期51-55,共5页
结合哈尔滨地铁八标段盾构区间施工测量方案和实际测量工作,从控制测量、联系测量和盾构机施工测量3个主要方面介绍地铁盾构区间施工各环节的主要测量工作,并以盾构机施工测量为重点,详细介绍盾构机施工测量的各项技术方法。在介绍各项... 结合哈尔滨地铁八标段盾构区间施工测量方案和实际测量工作,从控制测量、联系测量和盾构机施工测量3个主要方面介绍地铁盾构区间施工各环节的主要测量工作,并以盾构机施工测量为重点,详细介绍盾构机施工测量的各项技术方法。在介绍各项观测技术的同时,还将探讨提高各项施工测量精度的方法和措施。对其他地铁盾构区间施工测量工作有一定的借鉴作用。 展开更多
关键词 地铁 盾构 区间施工测量
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核电厂3H/14C混合样品测量计数区间的优化
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作者 苏凯 胡海 郑庆云 《产业与科技论坛》 2021年第9期39-40,共2页
核电机组运行过程中,在主回路系统中会产生3H和14C核素,部分3H和14C以气体/液态流出物形式排放至环境中,这是核电厂环境辐射的重要源项,因此准确测量3H和14C的活度具有重要的意义。对于单纯的3H或者14C的样品,可以通过液体闪烁仪测量其... 核电机组运行过程中,在主回路系统中会产生3H和14C核素,部分3H和14C以气体/液态流出物形式排放至环境中,这是核电厂环境辐射的重要源项,因此准确测量3H和14C的活度具有重要的意义。对于单纯的3H或者14C的样品,可以通过液体闪烁仪测量其全部能量范围内的计数来确定其活度,但对于3H/14C混合样品需要优化各自的能量区域,以减少相互的影响。通过分别测量3H、14C源的样品确认最佳测量区间,再通过配制混合源的方式进行实验测量,最终确定了当3H测量区间为:0.7~13Kev,14C测量区间为13~130Kev,两者相互影响达到最小化。 展开更多
关键词 3H 14C 混合样 测量区间
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集成光学电场探头测量HEMP的系统误差分析 被引量:3
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作者 石跃武 周辉 +6 位作者 聂鑫 朱志臻 王伟 杨静 孙蓓云 相辉 冯寒亮 《强激光与粒子束》 EI CAS CSCD 北大核心 2015年第7期145-149,共5页
讨论了集成光学电场探头测量高空电磁脉冲(HEMP)的系统误差。根据探测器传输函数和HEMP的表达式得出了误差方程。并通过对HEMP表达式的特征分析,对误差方程进行了简化。通过方程的求解,分析了探测器和HEMP波形的各项参数对测量结果的影... 讨论了集成光学电场探头测量高空电磁脉冲(HEMP)的系统误差。根据探测器传输函数和HEMP的表达式得出了误差方程。并通过对HEMP表达式的特征分析,对误差方程进行了简化。通过方程的求解,分析了探测器和HEMP波形的各项参数对测量结果的影响。结果表明:误差随着双指数波幅值、半宽/前沿和探测器工作点漂移的增大而增大;探测器的5%和10%系统测量误差对应的最大测量幅值分别为半波电场的0.165倍和0.23倍。该结论可为此类探测器的使用提供参考。 展开更多
关键词 高空核爆电磁脉冲 电光探头 电场测量 系统误差 线性测量区间
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水下单信标导航算法研究及置信区间分析 被引量:4
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作者 王燕 张新宇 +1 位作者 孙思博 付进 《哈尔滨工程大学学报》 EI CAS CSCD 北大核心 2022年第1期119-129,共11页
为了优化单信标导航算法中导航点的选取以提高导航精度,本文分析并比较了不同水下单信标导航算法的置信区间。考虑了3种典型的水下单信标导航算法:基于时延信息的单信标导航算法、基于方位角信息的单信标导航算法以及联合使用时延和方... 为了优化单信标导航算法中导航点的选取以提高导航精度,本文分析并比较了不同水下单信标导航算法的置信区间。考虑了3种典型的水下单信标导航算法:基于时延信息的单信标导航算法、基于方位角信息的单信标导航算法以及联合使用时延和方位角信息的单信标导航算法。本文首先基于偏微分矩阵建立了3种方法的导航误差和各测量误差的关系式,在此基础上利用导航误差的协方差矩阵分析了时延测量误差和方位角测量误差对3种方法导航结果置信区间分布的影响。此外,本文从水平位置精度因子和置信椭圆这2个角度对3种方法导航结果的置信区间的分布进行了比较。理论推导及仿真表明:时延测量误差和方位角测量误差基于导航点和声信标的相对几何位置关系影响置信区间的分布,且基于时延的单信标导航算法的导航结果和基于方位角的单信标的导航算法的导航结果具有互补的特性。 展开更多
关键词 单信标导航 时延 方位角 测量误差:置信区间 置信椭圆 水平位置精度因子 精度分析
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地铁盾构区间施工测量技术研究
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作者 任娜 《中文科技期刊数据库(引文版)工程技术》 2016年第4期00001-00001,共1页
在地铁施工过程中,盾构区间的施工测量是保障盾构正常推进的重要方式。通过做好盾构区间的施工测量,可以有效保障工程建设质量。本文对地铁盾构区间的施工测量技术进行简单分析。
关键词 地铁施工 盾构施工 区间测量 测量技术
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两种商品定量试剂盒分析性能的验证试验 被引量:2
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作者 杨曙梅 浦江 +2 位作者 张芹 王惠民 丛辉 《检验医学与临床》 CAS 2013年第3期301-302,304,共3页
目的验证甲胎蛋白(AFP)、癌胚抗原(CEA)商品定量试剂盒的分析性能。方法根据"中华人民共和国卫生行业标准WS/T xxx-2008"的要求,对AFP、CEA商品定量试剂盒分析性能进行验证。结果 AFP、CEA定量试剂盒的批内、批间精密度CV值... 目的验证甲胎蛋白(AFP)、癌胚抗原(CEA)商品定量试剂盒的分析性能。方法根据"中华人民共和国卫生行业标准WS/T xxx-2008"的要求,对AFP、CEA商品定量试剂盒分析性能进行验证。结果 AFP、CEA定量试剂盒的批内、批间精密度CV值均小于厂家声称的相应CV值;正确度试验结果的平均偏倚值均低于厂家声称的偏倚值;各项目的测量区间验证值结果与预测值接近,相关系数(r)>0.975,线性理想(斜率b接近1)。结论本研究所验证AFP、CEA定量试剂盒的精密度、正确度和线性范围3个方面均达到了临床应用的实验要求。 展开更多
关键词 性能验证 商品定量试剂盒 精密度 正确度 测量区间
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一种基于平均数据包长度的可变权值调度算法 被引量:3
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作者 李寅 周井泉 《计算机技术与发展》 2012年第9期116-118,122,共4页
近年来随着网络规模的扩大,一些对实时性要求较高的音频、视频业务的出现,对网络QoS保证提出了更高的要求。在区分服务下,分组调度技术是保证网络QoS的核心技术,也是实现网络拥塞控制管理,保证各业务带宽分配公平性的必要手段。调度算... 近年来随着网络规模的扩大,一些对实时性要求较高的音频、视频业务的出现,对网络QoS保证提出了更高的要求。在区分服务下,分组调度技术是保证网络QoS的核心技术,也是实现网络拥塞控制管理,保证各业务带宽分配公平性的必要手段。调度算法是保证网络服务质量(QoS)的核心技术,传统轮询调度WRR算法存在一个公平性问题,并不适用于数据包长度可变的网络。文中基于WRR算法提出一种改进算法,使其可以依据平均数据包长度自适应地改变权值,命名为CWRR。并通过仿真对新算法性能进行分析,如果测量区间是合适的,那么CWRR的公平性比WRR要好。 展开更多
关键词 轮询调度 带宽 测量区间 公平性
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双圈同轴型光纤传感器结构的优化与试验验证 被引量:3
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作者 杨睿 杨瑞峰 +1 位作者 郭晨霞 吴耀 《激光技术》 CAS CSCD 北大核心 2019年第3期324-328,共5页
为了验证用于测量物体表面形貌的双圈同轴型光纤传感器的数学模型的可行性、优化新结构光纤传感器中的参量以提高光纤传感器线性测量范围和灵敏度,采用了不影响调制特性曲线前坡数据的镜子纸作为反射面进行试验验证,并对新结构的光纤传... 为了验证用于测量物体表面形貌的双圈同轴型光纤传感器的数学模型的可行性、优化新结构光纤传感器中的参量以提高光纤传感器线性测量范围和灵敏度,采用了不影响调制特性曲线前坡数据的镜子纸作为反射面进行试验验证,并对新结构的光纤传感器进行了理论分析和数学建模,然后采用粒子群算法对新结构中的倾斜角度进行了优化。结果表明,以镜子纸为反射面所得的试验曲线与仿真调制特性曲线吻合,证明了用于测量物体表面形貌的双圈同轴型光纤传感器的数学模型的可行性;经粒子群算法优化后的倾斜角度为2.33°,此时前坡线性测量区间和灵敏度分别是倾斜角为零时的1.14倍和1.89倍。新结构的双圈同轴型光纤传感器展现出了良好的测量性能和应用前景。 展开更多
关键词 光纤光学 双圈同轴型光纤传感器 粒子群算法 倾斜角 线性测量区间 灵敏度
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光度、色度计量与装置
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《中国光学》 EI CAS 1999年第1期2-2,共1页
O432.3 99010010双光束测色仪中两路CCD信号处理=Two passCCD signal processing in dual—beam colormeasuring instruments[刊,中]/魏森泉,邹文栋,陈学岗,张小林,周哲,刘方宇(江西省科学院.江西。
关键词 测色仪 信号处理 双光束 光电积分 江西省 筛子式 色度计 哈尔滨 科学院 测量区间
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A New Approach to Measurement of Regional Inequality in Particular Directions 被引量:19
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作者 WANG Yang FANG Chuanglin +1 位作者 XIU Chunliang LIU Daqian 《Chinese Geographical Science》 SCIE CSCD 2012年第6期705-717,共13页
Regional inequality is a core issue in geography,and it can be measured by several approaches and indexes.However,the global inequality measures can not reflect regional characteristics in terms of spatiality and non-... Regional inequality is a core issue in geography,and it can be measured by several approaches and indexes.However,the global inequality measures can not reflect regional characteristics in terms of spatiality and non-mobility,as well as correctly explore regional inequality in particular directions.Although conventional between-group inequality indexes can measure the inequality in particular directions,they can not reflect the reversals of regional patterns and changes of within-group patterns.Therefore,we set forth a new approach to measure regional inequality in particular directions,which is applicable to geographic field.Based on grouping,we established a new index to measure regional inequality in particular directions named Particular Direction Inequality index(PDI index),which is comprised of between-group inequality of all data and between-group average gap.It can reflect regional spatiality and non-mobility,judge the main direction of regional inequality,and capture the changes and reversals of regional patterns.We used the PDI index to measure the changes of regional inequality from 1952 to 2009 in China.The results show that:1) the main direction of China's regional inequality was between coastal areas and inland areas;the increasing extent of inequality between coastal areas and inland areas was higher than the global inequality;2) the PDI index can measure the between-region average gap,and is more sensitive to evolution of within-region patterns;3) the inequality between the northern China and the southern China has been decreasing from 1952 to 2009 and was reversed in 1994 and 1995. 展开更多
关键词 regional inequality inequality indexes PDI index particular directions China
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Determinants of invasive strategy in elderly patients with non-ST elevation myocardial infarction 被引量:1
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作者 Antonin Negers Jacques Boddaert +5 位作者 Lucie Mora Jean-Louis Golmard Laura Moisi Ariel Cohen Jean-Philippe Collet Alice Breining 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2017年第7期465-472,共8页
Background Knowledge gaps across literature prevent current guidelines from providing the profile of elderly patients most likely to derive benefit fi^om invasive strategy (IS) in non ST-elevation myocardial infarct... Background Knowledge gaps across literature prevent current guidelines from providing the profile of elderly patients most likely to derive benefit fi^om invasive strategy (IS) in non ST-elevation myocardial infarction (NSTEMI). Furthermore, the benefit of IS in a real-world elderly population with NSTEMI remains unclear. The aims of this study were to determine factors that lead the cardiologist to opt for an IS in elderly patients with NSTEMI, and to assess the impact of IS on the 6-month all-cause mortality. Methods This multicenter prospective study enrolled all consecutive patients aged 〉 75 years old who presented a NSTEMI and were hospitalized in cardiology intensive care unit between February 2014 and February 2015. Patients were compared on the basis of reperfusion strategy (invasive or conservative) and living status at six months, in order to determine multivariate predictors of the realization of an IS and multivariate predictors of 6-month mor- tality. Results A total of 141 patients were included; 87 (62%) underwent an IS. The strongest independent determinants of IS were younger age [odds ratio (OR): 0.85, 95%-confidence interval (CI): 0.78-0.92; P 〈 0.001) and lower "Cumulative Illness Rating Scale-Geriatric" number of categories score (OR: 0.83, 95%CI: 0.73-0.95; P = 0.002). IS was not significantly associated with 6-month survival (OR: 0.80, 95%CI: 0.27-2.38; P = 0.69). Conclusions In real-world elderly patients with NSTEMI, younger patients with fewer comorbidities profited more often from an IS. However, IS did not modify 6-month all-cause mortality. 展开更多
关键词 COMORBIDITY Coronary angiography Decision making MORTALITY Myocardial infarction
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Application of Interval Newton Method to Solve Nonlinear Equations and Global Optimization
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作者 LI Shuang XU Caijun WANG Xinzhou 《Geo-Spatial Information Science》 2003年第1期24-27,33,共5页
The basic principle of interval arithmetic and the basic algorithm of the interval Newton methods are introduced.The prototype algorithm can not find any zero in an interval that has zero sometimes,that is,it is insta... The basic principle of interval arithmetic and the basic algorithm of the interval Newton methods are introduced.The prototype algorithm can not find any zero in an interval that has zero sometimes,that is,it is instable.So the prototype relaxation procedure is improved in this paper.Additionally,an immediate test of the existence of a solution following branch_and_bound is proposed,which avoids unwanted computations in those intervals that have no solution.The numerical results demonstrat that the improved interval Newton method is superior to prototype algorithm in terms of solution quality,stability and convergent speed. 展开更多
关键词 interval algorithm interval Newton method global optimization
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An Urban Open Space Extraction Method: Combining Spectral and Geometric Characteristics 被引量:1
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作者 ZHUGuobin DanG.Blumberg 《Geo-Spatial Information Science》 2004年第4期249-254,共6页
This paper introduces an advanced method based on remote sensing and Geographic Information System for urban open space extraction combining spectral and geometric characteristics. From both semantic and remote sensin... This paper introduces an advanced method based on remote sensing and Geographic Information System for urban open space extraction combining spectral and geometric characteristics. From both semantic and remote sensing perspectives, a hybrid hierarchy structure and class organization of open space are issues and mapped from one to another. Based on per-pixel and segmentation mechanism separately, two classification approaches are performed. Owing to prior of spatial aggregation and spectral contribution, the segmentation-based classification exhibits its superiority over a pixel-based classification. Finally a GIS-based post procedure is hired to eliminate some unsuitable open space components in both spatial and numerical constraints on the one hand, and separate open space some fabrics from fused remote sensing classes by defining their Shape Index on the other hand. The case study of Beer Sheva based on ASTER data proves this method is a feasible way for open space extraction. 展开更多
关键词 urban open space remote sensing geographic information systems (GIS) SEGMENTATION classification (ASTER
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基于单片机的智能电表设计
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作者 李泊文 车前 《开封大学学报》 2023年第4期76-78,共3页
设计了一种基于单片机的智能电表,不仅能测量自安装后的总电量,还能测量区间电量与瞬时电量,以达到实时监测和记录区间家庭用电情况的目的。本设计有较高的精度,并有一定的抗干扰能力。
关键词 单片机 智能电表 AD转换 区间测量 瞬时测量
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Field Capacity in Black Soil Region, Northeast China 被引量:9
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作者 DUAN Xingwu XIE Yun +2 位作者 LIU Gang GAO Xiaofei LU Hongmei 《Chinese Geographical Science》 SCIE CSCD 2010年第5期406-413,共8页
In this work, 23 black soil profiles were surveyed and 113 soil samples were collected to determine the field capacity (FC) of the black soil in Northeast China. The effectiveness of three methods measuring FC, the Wi... In this work, 23 black soil profiles were surveyed and 113 soil samples were collected to determine the field capacity (FC) of the black soil in Northeast China. The effectiveness of three methods measuring FC, the Wilcox method (WM), the undisturbed soil pressure plate method (PUM) and the air-dried sieved soil pressure plate method (PDM) were compared to select a suitable laboratory measurement method. Results show that the FC values measured by PDM are greater than those measured by PUM, and the values measured by PUM are greater than those measured by WM. PUM is more suitable for the determination of FC in the study area. One regression equation between PUM and PDM has been established through which undisturbed soil can be replaced by air-dried sieved soil, which is easier to get, to measure FC. FCs vary from 23.50% to 37.00%, with an average of 31.65%, which differ greatly among the 23 black soil profiles. FC is found to be significantly positively correlated with the silt content, clay content and bulk density of the soil, but significantly negatively correlated with the sand content. An empirical pedotransfer function is established to estimate the FC using available soil physical and chemical properties. 展开更多
关键词 Wilcox method plate method pedotransfer function field capacity black soil
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Using a 3D Interval Type-2 Fuzzy Interpolation System to Improve Modeless Robots Measurement and Calibration Accuracy
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作者 Ying Bai Dali Wang 《Journal of Control Science and Engineering》 2016年第2期71-81,共11页
This paper is an extended research for a novel technique used in the pose error compensations of the robot and manipulator calibration process based on an IT2FEI (interval type-2 fuzzy error interpolation) method. R... This paper is an extended research for a novel technique used in the pose error compensations of the robot and manipulator calibration process based on an IT2FEI (interval type-2 fuzzy error interpolation) method. Robot calibrations can be classified into model-based and modeless methods. A model-based calibration method normally requires that the practitioners understand the kinematics of the robot therefore may pose a challenger for field engineers. An alternative yet effective means for robot calibration is to use a modeless method; however with such a method there is a conflict between the calibration accuracy of the robot and the number of grid points used in the calibration task. In this paper, an interval type-2 fuzzy interpolation system is applied to improve the compensation accuracy of the robot in its 3D workspace. An on-line type-2 fuzzy inference system is implemented to meet the needs of on-line robot trajectory planning and control. The simulated results given in this paper show that not only robot compensation accuracy can be greatly improved, but also the calibration process can be significantly simplified, and it is more suitable for practical applications. 展开更多
关键词 Type-2 fuzzy interpolations interval type-2 fuzzy logic modeless robotic calibrations robot kinematics type-2 fuzzycontrol.
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Measuring coordination of economy-society and resource-environment based on major function oriented zoning: a case study of Pearl River Delta 被引量:2
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作者 FANG Zhong-quan WANG Zhang-jun 《Ecological Economy》 2010年第3期264-271,共8页
A reasonable coordination degree assessment of the social-economic development level and the resource-environment quality level are essential to ident the key factory of the development, and vital to determine the app... A reasonable coordination degree assessment of the social-economic development level and the resource-environment quality level are essential to ident the key factory of the development, and vital to determine the appropriate development strategy and achieve sustainable development. The major function oriented zoning plays a role in spatial coordination mainly' by spatial guidance and restriction, so. the proposal of major function oriented zoning gives a new train of thought to generate a coordination evaluation of economy-society and the resource-environment system, From the view of major function oriented zoning that considers resource environmental bearing capacity, existing development density and development potential, this paper constructs an index system and model of coordination evahtation with a case study on Pearl River Delta. The results have shown: (I) It can reveal the conflicts of economic-social development and resource-environment quality to ac- curately consider resource environmental bearing capacity, existing development densio~ and development po- tential; (2) The coordination degree between social-economy system and resource-environment system in Pearl River Delta continued to decline in the past 10 years. The spatial extent of coordination evoh,es.from coordina- tion in the whole Pearl River Delta to imbalance in the core areas, and at present, the uncoordinated areas have already diffused from core areas to the outlying regions: (3) Most regions of the Pearl River Delta are in uncoordinated condition When considering the coordination degree of economic-social development and resollrceenvironment quality, not as coordinated as some scholars considered. 展开更多
关键词 Major function oriented zoning Economy-society system Resource-environment system Coordination evalu- ation: the Pearl River Delta
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