探地雷达在贵州水利水电勘察中的应用

结合贵州福泉下翁溪水库、芙蓉江沙阡电站、冗各电站3个工程实例,介绍探地雷达勘探在岩溶、断层破碎带等不良地质构造勘察方面的应用.     

华北地台沉积岩型金矿床的找矿勘查意义

冀东地区沉积岩型金矿床主要赋存在中上元古界长城系和蓟县系巨厚钙－镁碳酸盐岩内,金矿化受层间角砾岩带控制。相比之下,内蒙古中西部沉积岩型金矿床主要产出在上元古界青白不钙质粉砂岩和板岩内,矿父母产状受层间构造破碎带控制。尽管上述金矿床的成矿环境、赋矿围岩和成矿时代存在一定差别,但是它们均以埋藏浅、规模大、物质组分简单和易选冶为特点。为突出这两类金矿床的区域性特征,前者命为“长城式”,后者则确定为“阿拉     

河北省沙尘暴时空分布特征及其防治对策研究

该文分析河北省沙尘暴的气候特征 ,并探讨其成因 ,研究结果表明 ,坝上地区是河北省沙尘暴的多发区 ,干旱多大风的春季是发生沙尘暴天气最多的季节。最后提出了以植树种草为核心内容的综合防治对策。     

城市广告业集群分布模式——以深圳为例

广告业是商品经济和消费文化的必然结果,世界发达国家的广告业具有明显的创意和文化产业之特点。我国广告业在改革开放以后获得了恢复和快速发展。以深圳为例,将广告业作为文化产业服务与生产体系,采用广告业业内人士的分类框架,建构和分析了深圳广告产业的基本结构特点。运用GIS空间分析工具,识别了广告业在城市空间的分布和集群形态。结合对广告公司的深入访谈,提出广告业集群的形成和关联机制具有广告主主导型、媒体依赖型、产业关联型、成本导向型、环境氛围导向型和社会关系型等6种模式。由“广告公司-广告主-广告媒介”组成的三角博弈关系以及三方各自可能到达的地理空间范围,共同作用,构成了广告公司生存、发展、区位选择、空间流动和地域拓展的核心动力机制,任何一方的实力和地理空间变化都可能影响一个城市和地域整体广告业的生态格局。     

Identifying separate impacts of climate and land use/cover change on hydrological processes in upper stream of Heihe River,Northwest China

Climate change and land use/cover change (LUCC) are two factors that produce major impacts on hydrological processes. Understanding and quantifying their respective influence is of great importance for water resources management and socioeconomic activities as well as policy and planning for sustainable development. In this study, the Soil and Water Assessment Tool (SWAT) was calibrated and validated in upper stream of the Heihe River in Northwest China. The reliability of the SWAT model was corroborated in terms of the Nash–Sutcliffe efficiency (NSE), the correlation coefficient (R), and the relative bias error (BIAS). The findings proposed a new method employing statistical separation procedures using a physically based modeling system for identifying the individual impacts of climate change and LUCC on hydrology processes, in particular on the aspects of runoff and evapotranspiration (ET). The results confirmed that SWAT was a powerful and accurate model for diagnosis of a key challenge facing the Heihe River Basin. The model assessment metrics, NSE, R, and BIAS, in the data were 0.91%, 0.95%, and 1.14%, respectively, for the calibration period and 0.90%, 0.96%, and ?0.15%, respectively, for the validation period. An assessment of climate change possibility showed that precipitation, runoff, and air temperature exhibited upward trends with a rate of 15.7 mm, 6.1 mm, and 0.38 °C per decade for the 1980 to 2010 period, respectively. Evaluation of LUCC showed that the changes in growth of vegetation, including forestland, grassland, and the shrub area have increased gradually while the barren area has decreased. The integrated effects of LUCC and climate change increased runoff and ET values by 3.2% and 6.6% of the total runoff and ET, respectively. Climate change outweighed the impact of LUCC, thus showing respective increases in runoff and ET of about 107.3% and 81.2% of the total changes. The LUCC influence appeared to be modest by comparison and showed about ?7.3% and 18.8% changes relative to the totals, respectively. The increase in runoff caused by climate change factors is more than the offsetting decreases resulting from LUCC. The outcomes of this study show that the climate factors accounted for the notable effects more significantly than LUCC on hydrological processes in the upper stream of the Heihe River.     

滇西南与花岗岩有关的锡矿床时空分布与成矿作用

滇西锡矿带与全球著名的东南亚锡矿带具有相似的成矿地质背景,其成矿规律与资源潜力一直是研究热点。本文在前人已有研究的基础上,探讨了滇西南锡矿时空分布规律与成矿作用。滇西南锡矿主要分布在腾冲地体、保山地体与昌宁-孟连造山带。已有的年代学数据显示腾冲地体发育三期锡成矿事件,分别为125～120Ma,75～68 Ma,52～47 Ma。本文在保山地体识别出晚新生代(约32～24 Ma)和晚白垩世(约75 Ma)两期锡成矿作用,进一步厘定了昌宁-孟连造山带东部三叠纪临沧花岗岩体中锡成矿时代为三叠纪(约235～220 Ma)。提出滇西南与三叠纪花岗岩有关的锡成矿作用发生于古特提斯洋闭合后碰撞环境,与早白垩世花岗岩有关的锡矿形成于中特提斯洋闭合后碰撞环境,与晚白垩世—古近纪花岗岩有关的锡成矿作用与新特提斯洋俯冲和板片回撤有关,而保山地体晚新生代锡矿则可能与新生代隐伏的新生代花岗岩有关,其侵位可能与走滑断裂活动诱发的软流圈上涌和地壳熔融有关。滇西南含锡花岗岩多为复式花岗岩体中晚阶段的高分异花岗岩(如二云母花岗岩或白云母花岗岩)。保山地体三叠纪花岗岩中的锡矿成矿时代显著晚于赋矿围岩,应注重加强成矿期花岗...     

加拿大西北航道与俄罗斯北方海航道管理的对比研究

加拿大和俄罗斯分别是北极西北航道与北方海航道的实际管理者。本论文采用对比研究的方式分析两国北极航道管理举措的异同点,以此为切入点,深入解析两国航道主权诉求的异同点,了解两国在诉求北极航道主权及实现航道经济潜能之间的权衡,探究两国对待未来北极航道商业通航的态度。并且,两国不同的北极航道管理举措还可以揭示各自对航道在国家政治军事安全重要性的认知差异、对海域环境保护的不同重视程度。北极航道管理举措折射出两国北极航道的政策现状及走向,围绕其展开的对比研究有助于国际社会更好应对未来北极航道的全面商业通航。     

Effects of urbanization on daily temperature extremes in North China简

The regional changes of daily temperature extremes in North China caused by ur- banization are studied further from observed facts and model estimates on the basis of ho- mogenized daily series of maximum and minimum temperature observations from 268 mete- orological stations, NCEP/DOE AMIP- Ⅱ reanalysis data （R-2）, and the data of simulations by regional climate model （RegCM3）. The observed facts of regional warming on long time scales are obtained by analyzing the indices of temperature extremes during two time periods of 1961-2010 and 1951-2010. For urbanization effect, the contributions to decreases in an- nual and winter diurnal temperature range （DTR） are 56.0% and 52.9%, respectively, and increases in the lowest minimum temperature （TNn） are 35.7% and 26.2% by comparison of urban and rural observations. Obtained by R-2 data with observations for contrast, on the other hand, increase in the number of annual warm nights （TN90p） contributed by urbaniza- tion is 60.9%. And observed facts of regional warming in daily temperature extremes are also reflected in the simulations, but what difference is urbanization progress at rural areas in North China would be prominent in the next few years relative to urban areas to some extent from model estimates.     

基于工程反问题的圆管湍流流体热物性参数反演

给出一种利用测定圆管对流换热温度场求解湍流流体热物性参数的方法。根据边界层理论,对管内湍流强制对流换热控制方程组进行简化,并通过考虑湍流运输中的密度脉动,对传统的混合长度湍流模型进行改进,基于该计算模型求解圆管湍流模型的温度场。采用Levenberg-Marquardt方法通过测量温度场反演了湍流对流换热控制方程中的黏度系数。结果表明,利用反问题方法通过测定温度场反演湍流流动流体的热物性参数具有可行性,精确度较高。     

Effects on Three-Dimensional Geosynchronous Circular SAR Imaging by Orbit Errors

Circular SAR imaging on the geosynchronous orbit is an innovative SAR imaging mode, which can perform high resolution three-dimensional (3D) imaging with continuous observations for a large area. However, for geosynchronous satellites the orbit is severely disturbed by perturbing effects, and the orbit error will be an important factor influencing the SAR imaging on the geosynchronous orbit. In this paper, the effects of the orbit error on performances of 3D geosynchronous circular SAR (GEOCSAR) imaging are analyzed. The error model is firstly made, and then the orbit error propagating into the distance from the radar to the target (range) is derived. Furthermore, the effects of different components of the range error on the quality of focused SAR signals are deduced, based on the 3D GEOCSAR signal model with time-domain correlation algorithm. The analyses and simulations will quantify and verify the required accuracies of GEOCSAR orbit estimation for ensuring the 3D imaging quality.