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921.
推进城乡一体化协调发展是事关海南自由贸易港建设成效的重点任务之一,新的发展环境及政策框架正促使海南省城乡关系快速转型。采用变异系数法、耦合协调度模型、回归模型,从城乡空间、经济和社会等维度,分析了建省办特区以来海南省城乡关系演化特征及驱动机制。结果表明:①建省办特区以来,海南省城乡协调综合指数呈现明显的先降后升态势,由1988年的0.319 9到1993年的0.153 9,2019年达0.851 9;②海南省城乡各子系统耦合度和耦合协调度均呈波动上升态势,耦合度主要处于磨合和高水平耦合阶段,耦合协调度由轻度失调转变为初级协调,最后达到中级协调,城乡各子系统间相互作用增强;③海南省城乡关系演化经历城乡二元加剧、城乡二元固化、城乡关系趋缓和城乡一体化初期四个阶段,低水平城乡均衡发展是重要特征,高质量推进城乡一体化协调发展是关键;④经济发展对城乡协调发展影响最为明显,但呈负相关,其次为市场消费、产业结构、乡村发展、交通通达性、城镇发展和政府行为,对外开放对城乡关系演化影响相对较弱;⑤制度创新、对外合作、产业优化、城镇建设和乡村振兴是推进城乡融合发展的重要路径。 相似文献
922.
Yang Han Yunsheng Zhao Yeqiao Wang 《Journal of the Indian Society of Remote Sensing》2014,42(4):727-732
Moisture is one of the important parameters in soil polarized spectrum. It has great significance in soil remote sensing band selection and image interpretation; it also provides the information for soil investigation and analysis on physical and chemical properties. In this paper we tested and analyzed the soil polarized spectrum with different moisture in 350?~?2,500 nm wavelength, to study on the relationship between soil polarized spectral data and moisture, to determine the spectral response and changes in soil moisture, and establish models between spectral data and soil moisture. We also designed a orthogonal test on the various factors that affect soil polarized spectral characteristics, in which we studied soil moisture, polarized angle, detected angle and azimuth of the various factors and their interactions. The results showed it was most significant that the soil moisture and the interaction of soil moisture and polarized angle, followed by the interaction effect of detected angle and moisture, while the polarized angle had a little impact on the soil polarized spectrum. 相似文献
923.
924.
黄平 《测绘与空间地理信息》2014,(5):164-166
随着城市规模的迅速扩大,对输配送电网的服务和管理提出了更高的要求,传统的管理模式已不能适应电力行业的需要。输配送电网GIS主要针对输变电主干网及子干网输配电网设备设施空间分布数据、电网运行状态等信息进行集中管理。系统的建设目标是对电网的网络关系进行分析,开发出基于地理信息技术的电网管理系统,形成以地理位置为查询主线索的多层次多方式的信息管理系统。本文结合长沙电业局的输配送管网建设现状,结合实际工作需求,全面提高电缆管理所的综合服务和管理水平,对电力配网地理信息系统的功能和框架结构等进行全面描述和开发。 相似文献
925.
926.
Carrying Capacity of Marine Region in Liaoning Province 总被引:1,自引:1,他引:1
Carrying capacity is one of important studies on coordinating development of population,resources,and environment.At present,the researches on it mainly concentrate on the carrying capacity for population and economy,such as the water resources carrying capacity,the land resources carrying capacity,the environment carrying capacity,etc.Based on the related theories and methods,this paper creatively proposed the concept and meaning of carrying capacity of marine region,and formed the appraisal system.According to the developing situation of marine economy of Liaoning Province in recent years,and by employing the method of the state space,this paper also measured the carrying capacity and carrying state of marine region and discussed the sustainable problems of marine economy of Liaoning.The research results show that the carrying state of marine region of Liaoning is in the state of overloading at present,but taking a favorable turn. 相似文献
927.
???ú????????????????????????????????2001??3??~2006??7????????????????Satoβ????????????????????????????????β??????(20 s??30 s??40 s)??QC?,????????QC????????????? 35.8 f 0.95??46.0 f 0.94 ??59.4 f 0.93 ??Q0?????????????????????????????????????????????,?о?????Q0???????????QC???????????????????????????????? 相似文献
928.
Xiang‐Jun Liu Zhong‐Ping Lai 《Boreas: An International Journal of Quaternary Research》2013,42(2):333-341
Sand wedges and ice‐wedge casts in the Qinghai Lake area on the northeastern Qinghai‐Tibetan Plateau (QTP) occur within alluvial gravel or river terrace deposits. In this study, we report the results of quartz Optically Stimulated Luminescence (OSL) dating of the infill of five relict sand wedges and one ice‐wedge cast. Combining our dating results with previously published luminescence ages of permafrost wedges in the Qinghai Lake area, we show that sand/ice wedges formed at c. 62 ka, c. 45 ka and between 30 and 15 ka, and that the mean annual air temperature (MAAT) was depressed by at least ~3°C relative to present during the sand/ice‐wedge formation periods. This new work is partially corroborated by post‐LGM proxy records from lakes and aeolian deposits reported from the northeastern QTP. It also significantly extends the palaeoenvironmental record in the region in the period before the LGM, when other proxy records are rare, allowing a better understanding of the palaeoenvironmental conditions on the northeastern QTP. 相似文献
929.
Suspended matter is an important indicator of water quality in freshwater systems. The flood‐induced turbidity current plays a dominant role in the seasonal dynamic of suspended matter in the Liuxihe Reservoir (23°45′50″N; 113°46′52″E), a large, stratified reservoir at the Tropic of Cancer in southern China. Field measurements show that loading and distribution of suspended matter in the reservoir differ in typical wet, dry and medium years, as a result of different discharge volumes and water level variation patterns. Using historical data and the practical demand for water supply and flood control, we generalized two feasible reservoir operational modes: flood impounding mode (drawing down the reservoir to a low level before flood events to impound inflow during the flooding season) and moderate level change mode (drawing down the reservoir to a moderate level before flood events, then keeping the level within the flood control level during runoff events). To examine the effects of different operational modes and outlet depths on the reservoir's flood‐induced turbidity current, a numerical simulation model was applied in three types of hydrological conditions. The results show that the mode with moderate drawdown and recharge processes can decrease loading of suspended matter in spring and promote turbidity current release during flood events, and upper withdrawal can improve the effects of turbid water release. We suggest that more attention should be focused on water quality management in the reservoir operation stage, severe artificial water level fluctuation being avoided and selective withdrawal becoming an optional management measure. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
930.
This paper presents an iterative, incremental pressure‐stabilized fractional step algorithm for coupled hydro‐mechanical problems with mixed formulations of the displacement–pressure ( u –p) model in saturated soil dynamics that allows the use of finite elements with equal low order of interpolation approximation of u and p. In comparison with the original fractional step algorithm, the distinct features of the proposed algorithm lie in its enhanced stability owing to the introduction of both an iteration procedure and a finite increment calculus (FIC) process into the algorithm. The introduction of the iterative procedure makes the velocity term satisfy the momentum conservation equation in an implicit sense and allows much larger time step sizes to be used than those limited in existing explicit and semi‐implicit versions of the algorithm. The introduction of the FIC process removes the dependence of the stability of the proposed algorithm on the time step size, as a result it allows to using the incremental version of the algorithm and evades the minimum time step size requirement presented in the existing versions of the fractional step algorithm that restricts the application of the algorithm to saturated soil dynamics problems with high frequencies. Numerical experiments demonstrate the effectiveness and improved performance of the proposed iterative pressure‐stabilized fractional step algorithm. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献