“城市区域”主义下的中国区域治理模式重构——珠三角城际铁路的实证   总被引：1，自引：0，他引：1  

张衔春  栾晓帆  李志刚 《地理研究》2020,39(3):483-494

中国的区域治理模式长期以来呈现出阶段性演化的特征。特别是近些年,传统省-市分层设权的权力组织关系被动态的、反复连续性的博弈所取代。本研究借助政治经济学与人文地理学关于“国家空间再中心化”及组织社会学者的“行政发包制”理论,立足区域基础设施项目,即“珠三角城际铁路网”展开实证,系统分析其规划、建设及运营过程。并聚焦其中的事权与财权动态演变过程,解析省政府的角色定位和省市关系的演变等两大关键问题,揭示中国城市区域治理重构的内在逻辑。研究发现：一方面,省政府的角色定位由“分包商”和“协调者”逐渐转变为协调与发展并重的新角色定位;同时,省市关系由结构化的“行政发包”转化为多轮协商的动态博弈连续体。  相似文献   

Influence of marine phytoplankton, transition metals and sunlight on the species distribution of chromium in surface seawater     

Shun-Xing Li  Feng-Ying Zheng  Hua-Sheng Hong  Nan-sheng Deng  Lu-Xiu Lin 《Marine environmental research》2009,67(4-5):199-206

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凸包插值算法的改进与实现     

宫煦利  梅生强  王泽民  姚宜斌  黄石磊 《测绘信息与工程》2009,34(2):40-42

研究了凸包插值算法在n维欧拉空间构造Delaunay三角网的应用，提出了其三角剖分不惟一的重大缺陷，采用了限制区域生长法解决了这一缺陷。  相似文献   

An evaluation of the exposure in nadir observation of the JEM-EUSO mission     

《Astroparticle Physics》2013

We evaluate the exposure during nadir observations with JEM-EUSO, the Extreme Universe Space Observatory, on-board the Japanese Experiment Module of the International Space Station. Designed as a mission to explore the extreme energy Universe from space, JEM-EUSO will monitor the Earth’s nighttime atmosphere to record the ultraviolet light from tracks generated by extensive air showers initiated by ultra-high energy cosmic rays. In the present work, we discuss the particularities of space-based observation and we compute the annual exposure in nadir observation. The results are based on studies of the expected trigger aperture and observational duty cycle, as well as, on the investigations of the effects of clouds and different types of background light. We show that the annual exposure is about one order of magnitude higher than those of the presently operating ground-based observatories.  相似文献   

便携式高频地波雷达台湾海峡浪高观测   总被引：2，自引：1，他引：1  

ZHOU Hao  ROARTY Hugh  WEN Biyang 《海洋学报(英文版)》2015,34(1):73-78

As an important equipment for sea state remote sensing, high frequency surface wave radar(HFSWR) has received more and more attention. The conventional method for wave height inversion is based on the ratio of the integration of the second-order spectral continuum to that of the first-order region, where the strong external noise and the incorrect delineation of the first- and second-order Doppler spectral regions due to spectral aliasing are two major sources of errors in the wave height. To account for these factors, two more indices are introduced to the wave height estimation, i.e., the ratio of the maximum power of the second-order continuum to that of the Bragg spectral region(RSCB) and the ratio of the power of the second harmonic peak to that of the Bragg peak(RSHB). Both indices also have a strong correlation with the underlying wave height. On the basis of all these indices an empirical model is proposed to estimate the wave height. This method has been used in a three-months long experiment of the ocean state measuring and analyzing radar, type S(OSMAR-S), which is a portable HFSWR with compact cross-loop/monopole receive antennas developed by Wuhan University since 2006. During the experiment in the Taiwan Strait, the significant wave height varied from 0 to 5 m. The significant wave heights estimated by the OSMAR-S correlate well with the data provided by the Oceanweather Inc. for comparison, with a correlation coefficient of 0.74 and a root mean square error(RMSE) of 0.77 m. The proposed method has made an effective improvement to the wave height estimation and thus a further step toward operational use of the OSMAR-S in the wave height extraction.  相似文献   

便携式消费级无人机相机标定有效性评估   总被引：1，自引：0，他引：1  

李冀  熊晶  熊保颂  吴星宇  张朝阳  李雪 《测绘通报》2021,(4):131-135

本文针对近年来在各行业中广泛使用的便携式消费级无人机开展了相机标定有效性研究,分别通过室内标定场和后处理软件对相机进行标定和自标定,在对比无相机标定、飞前相机标定、飞后相机标定和自标定迭代校正等方法所得成图精度后,对不同相机标定方案的有效性进行了评估。结果表明：各种方案成图总体精度差别不大;飞前、飞后相机标定与无相机标定的成图精度相当;自标定迭代校正的成图精度略高于其他方案。可见采用航拍照片自标定参数迭代校正的方法更适合于飞行控制精度和成像系统稳定性都不高的便携式消费级无人机相机标定。  相似文献   

对地观测高光谱激光雷达发展及展望     

龚威  史硕  陈必武  宋沙磊  牛铮  王成  管海燕  李伟  高帅  林沂  孙嘉  杨健  杜霖 《遥感学报》2021,25(1):501-513

对目标空间三维—光谱信息的高分辨一体化获取与应用,是对地观测技术发展的前沿科学问题。结合高光谱成像与激光雷达测距的技术优势,对地观测多光谱/高光谱激光雷达遥感技术手段应运而生,并成为遥感技术未来发展的重要方向。本文分3个阶段详细回顾了对地观测高光谱激光雷达系统的发展历程,并针对其独有数据类型阐述了数据处理研究方面的探索研究。最后,重点分析了高光谱激光雷达在测绘领域、农林业领域的重大应用潜力,展望了未来对地观测高光谱激光雷达发展面临的机遇和挑战。  相似文献   

Spatial and temporal analysis of drought using entropy-based standardized precipitation index: a case study in Poyang Lake basin,China     

Xingjun Hong  Shenglian Guo  Lihua Xiong  Zhangjun Liu 《Theoretical and Applied Climatology》2015,122(3-4):543-556

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The Influence of Merges with Various Mass Ratios on the Spins of Black Holes     

Zhang Jin-jin  Du Pu  Wang Jian-min 《Chinese Astronomy and Astrophysics》2010,34(1):13-22

The distribution of black hole spins in consideration of only the effect of merges is discussed. The angular momentum after merging is treated via the post-Newtonian approximation, and the effects of merges under different conditions are simulated by adopting the Monte Carlo method. The obtained results indicate that the major merge cannot make the distribution of black hole spins stable, but the minor merge can make the black hole spin smoothly slow down. The distribution of black hole spins can stay at a stable level with the overwhelming proportion of small spins, when the mass ratio of merging black holes takes the form of power-law function. In addition, based on the simulated results, the possible relationship between radio-loud active galactic nuclei (AGNs) and black hole spins is also discussed. Finally, the distribution of radio loudness is calculated and presented.  相似文献   

我国高放废物处置库的选址与能动断层研究     

李愿军 《震灾防御技术》2007,2(4):401-408

随着我国核电工业建设步伐的加快,高放废物处置库的场址选择成为当前极为紧迫的课题。本文分析了甘肃北山高放废物处置库的选址现状,提出应加快相关核安全法规的建设以指导场址的选择;应对北山地区补充地震地质调查工作,特别是对区内的几条断层要进行断层能动性的研究。这对场址的适宜性是一个带有颠覆性的问题。  相似文献