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541.
542.
According to the connotation and structure of science and technology resources and some relevant data of more than 286 cities at prefecture level and above during 2001–2010, using modified method—Data Envelopment Analysis(DEA), science and technology(ST) resource allocation efficiency of different cities in different periods has been figured out, which, uncovers the distributional difference and change law of ST resource allocation efficiency from the time-space dimension. Based on that, this paper has analyzed and discussed the spatial distribution pattern and evolution trend of ST resource allocation efficiency in different cities by virtue of the Exploratory Spatial Data Analysis(ESDA). It turned out that:(1) the average of ST resource allocation efficiency in cities at prefecture level and above has always stayed at low levels, moreover, with repeated fluctuations between high and low, which shows a decreasing trend year by year. Besides, the gap between the East and the West is widening.(2) The asymmetrical distribution of ST resource allocation efficiency presents a spatial pattern of successively decreasing from Eastern China, Central China to Western China. The cities whose ST resource allocation efficiency are at higher level and high level take on a cluster distribution, which fits well with the 23 forming urban agglomerations in China.(3) The coupling degree between ST resource allocation efficiency and economic environment assumes a certain positive correlation, but not completely the same. The differentiation of ST resource allocation efficiency is common in regional development, whose existence and evolution are directly or indirectly influenced by and regarded as the reflection of many elements, such as geographical location, the natural endowment and environment of ST resources and so on.(4) In the perspective of the evolution of spatial structure, ST resource allocation efficiency of the cities at prefecture level and above shows a notable spatial autocorrelation, which in every period presents a positive correlation. The spatial distribution of ST resource allocation efficiency in neighboring cities seems to be similar in group, which tends to escalate stepwise. Meanwhile, the whole differentiation of geographical space has a diminishing tendency.(5) Viewed from LISA agglomeration map ofST resource allocation efficiency in different periods, four agglomeration types have changed differently in spatial location and the range of spatial agglomeration. And the continuity of ST resource allocation efficiency in geographical space is gradually increasing. 相似文献
543.
冰芯作为气候环境信息的良好载体,在研究过去大气环流异常中具有其他气候代用指标难以比拟的优势。本文重点综述了南极冰芯气候记录与南半球环状模(SAM-Southern Annular Mode)的关联特征:SAM与冰芯记录为同期变化,冰芯中NO-3、海盐组分(以Na+为代表)和水同位素比值δ18O同SAM指数具有较好的关联性;冰芯中SO2-4和MSA同SAM存在一定的关联,但相关性不显著;西南极冰芯记录的积累率同SAM具有较强的关联。需要说明的是,冰芯中各参数与SAM的相关性存在较大的空间差异。 相似文献
544.
Seung Man An Ho-Young Lee Byungsoo Kim Chae-Yeon Yi Jeong-Hee Eum 《International journal of geographical information science》2014,28(12):2511-2532
A major obstacle of the interdisciplinary communications for decision-making is that each participant prefers the solution from their own area because current collaboration systems cannot effectively mediate among many alternatives. If a visual collaboration system could display multiple alternatives in a single visual presentation, users would be able to compare alternatives with only a few variables, where all other parameters are fixed, at least from a visual perspective. In this study, we developed a visualization tool to support a microscale air quality (MSAQ) management group, the members of which often need to compare the effects of many alternative control methods. The main achievements of this study are: (1) three-dimensional (3D) visualization of the MSAQ using a 3D city model and (2) development of a geospatial spreadsheet (GS) to facilitate visual comparisons, thereby improving decision-making by making it easy to compare differences based on realistic visual display items. A questionnaire-based survey showed that use of the GS could generate a shared perspective and provide a spatiotemporal context for the participants, thereby making it easy to compare, mediate and reach decisions when confronted with many alternatives. 相似文献
545.
Propagation of vertical and horizontal source data errors into a TIN with linear interpolation 总被引:1,自引:0,他引:1
Lei Fan Joel Smethurst Peter Atkinson William Powrie 《International journal of geographical information science》2014,28(7):1378-1400
Digital elevation models (DEMs) have been widely used for a range of applications and form the basis of many GIS-related tasks. An essential aspect of a DEM is its accuracy, which depends on a variety of factors, such as source data quality, interpolation methods, data sampling density and the surface topographical characteristics. In recent years, point measurements acquired directly from land surveying such as differential global positioning system and light detection and ranging have become increasingly popular. These topographical data points can be used as the source data for the creation of DEMs at a local or regional scale. The errors in point measurements can be estimated in some cases. The focus of this article is on how the errors in the source data propagate into DEMs. The interpolation method considered is a triangulated irregular network (TIN) with linear interpolation. Both horizontal and vertical errors in source data points are considered in this study. An analytical method is derived for the error propagation into any particular point of interest within a TIN model. The solution is validated using Monte Carlo simulations and survey data obtained from a terrestrial laser scanner. 相似文献
546.
Influences of large-scale climatic phenomena, such as the E1Nifio/La Nifia-Southem Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO), on the temporal variations of the annual water discharge at the Lijin station in the Huanghe (Yellow) River and at the Datong station in the Changjiang (Yangtze) River were examined. Using the empirical mode decomposition-maximum entropy spectral analysis (EMD- MESA) method, the 2- to 3-year, 8- to 14-year, and 23-year cyclical variations of the annual water discharge at the two stations were discovered. Based on the analysis results, the hydrological time series on the inter- annual to interdecadal scales were constructed. The results indicate that from 1950 to 2011, a significant downward trend occurred in the natural annual water discharge in Huanghe River. However, the changes in water discharge in Changjiang River basin exhibited a slightly upward trend. It indicated that the changes in the river discharge in the Huanghe basin were driven primarily by precipitation. Other factors, such as the precipitation over the Changjiang River tributaries, ice melt and evaporation contributed much more to the increase in the Changjiang River basin. Especially, the impacts of the inter-annual and inter-decadal climate oscillations such as ENSO and PDO could change the long-term patterns of precipitation over the basins of the two major rivers. Generally, low amounts of basin-wide precipitation on interannual to interdecadal scales over the two rivers corresponded to most of the warm ENSO events and the warm phases of the PDO, and vice versa. The positive phases of the PDO and ENSO could lead to reduced precipitation and consequently affect the long-term scale water discharges at the two rivers. 相似文献
547.
???1999??2012???????????????????????????????λ????????????????????????λ??????GPS??????????????????????仯?????????о?????????????λ??GPS????????仯??????????????????仯?????????????????????????????????????λ????????GPS?????????С????ζ??????????????????????λ???????GPS?????????????ζ??????3??????????λ?仯????GPS????????????????г???????? 相似文献
548.
Wave effect on the ocean circulations through mass transport and wave-induced pumping 总被引:2,自引:0,他引:2
The wave Coriolis-Stokes-Force-modified ocean momentum equations are reviewed in this paper and the wave Stokes transport is pointed out to be part of the ocean circulations. Using the European Centre for Medium-Range Weather Forecasts 40-year reanalysis data (ERA-40 data) and the Simple Ocean Data Assimilation (SODA) version 2.2.4 data, the magnitude of this transport is compared with that of wind-driven Sverdrup transport and a 5-to-10-precent contribution by the wave Stokes transport is found. Both transports are stronger in boreal winter than in summers. The wave effect can be either contribution or cancellation in different seasons. Examination with Kuroshio transport verifies similar seasonal variations. The clarification of the efficient wave boundary condition helps to understand the role of waves in mass transport. It acts as surface wind stress and can be functional down to the bottom of the ageostrophic layer. The pumping velocities resulting from wave-induced stress are zonally distributed and are significant in relatively high latitudes. Further work will focus on the model performance of the wave-stress-changed-boundary and the role of swells in the eastern part of the oceans. 相似文献
549.
基于数值模拟的渤海海域地震海啸危险性定量化研究 总被引:1,自引:1,他引:0
根据地震海啸产生的条件,结合渤海海域的地形特征、地质构造、地震学特征和历史地震及海啸记录对渤海海域潜在的地震海啸进行了数值模拟研究。分析了渤海可能引发地震海啸的震源区域,讨论了渤海发生海啸灾害的可能性。文中通过数值模拟再现了渤海历史上几次规模较大的地震事件可能引发的海啸情景,研究分析了可能的地震海啸在渤海及周边海域的传播过程及波动特征.地震海啸传播模型采用基于四叉树原理的自适应网格加密技术,有效解决了局部分辨率与计算效率之间的矛盾。数值计算包括地震海啸产生及传播过程。利用该模型对渤海潜在的地震海啸进行了数值计算,基于数值计算结果定量阐述了渤海海域潜在地震海啸对渤海局部岸段及北黄海沿岸的影响,给出了渤海可能地震海啸危险性划分;研究结果将为我国海啸危险性分析和海啸预警技术研究工作提供技术支持。 相似文献
550.
本文研究了水环境急性低氧胁迫对卵形鲳鲹Trachinotus ovatus选育群体血液生化指标的影响。实验设计了急性低氧试验组和对照组,每组3个平行。结果显示,急性低氧胁迫后选育群体的血清离子含量与对照组相比都有不同程度的升高,其中钠、氯、钙浓度与对照组相比差异显著(p0.05),铁浓度极显著高于对照组(p0.01);血清蛋白、尿酸、肌酐、血脂、血糖等指标的差异较大,其中尿酸、肌酐极显著高于对照组(p0.01),总蛋白、总胆固醇显著低于对照组(p0.05);血清中肌酸激酶含量极显著高于对照组(p0.01),肌酸激酶同工酶显著高于对照组(p0.05),γ-谷氨酰转肽酶含量显著低于对照组(p0.05);其他指标均有不同程度的升高或降低,但差异不显著。研究表明,急性低氧胁迫造成卵形鲳鲹鳃、肾、心脏和肝脏损伤,免疫力下降。 相似文献