1959-2008年广西西江流域洪涝气候特征

 利用1959-2008年西江流域气象测站降水资料、西江干流及其支流年最高水位资料,建立逐年洪涝发生站次序列,并分析其时空特征和演变规律。结果表明：西江干流发生洪涝的频率比各支流大,各支流的中下游发生洪涝频率比上游大;西江流域洪涝的发生站次具有较显著的阶段性和突变性特征,主要突变发生在1967年和1993年;近16 a洪涝发生频率显著偏多,流域性大洪涝基本集中在这一时期。了解西江流域洪涝变化的规律,有利于提高洪涝灾害评估和预测水平,为防灾减灾提供科学依据。     

Transport of waste heat from a nuclear power plant into coastal water

A numerical and experimental modeling is presented for studying the transport of waste heat from a nuclear power plant into coastal water by using a full-field physical model with scale distortion, a local physical model with normal scale and a depth-averaged k− turbulence model with a modified second-order upwind scheme. Field investigations are also used to provide the calibration and validation of the modeling. A case study simulating the turbulent tidal flow and waste heat transport in the coastal water near Daya Bay Nuclear Power Plant in Southern China was conducted. The experimental result of the case study shows that the water temperature in coastal water was a little oversimulated near the surface and was a little undersimulated near the bottom of heated-water layer by the full-field physical model. The numerical study shows that the depth-averaged k− turbulence model presented a satisfied prediction of turbulent tidal flow and far-field temperature distribution in coastal water, although the near-field stratification due to the heated water effluent was not accounted for. The result of the effect of scale distortion on physical model shows that a full-field physical model with a scale distortion of 10 produced a satisfied result of temperature distribution in the present case study.     

拉林铁路板块缝合带隧道地应力分析

青藏高原板块缝合带为印度板块和欧亚板块两大陆块的缝合区域,带区地质条件复杂,构造运动强烈。川藏线拉林铁路几乎沿雅鲁藏布江缝合带展布,高地应力问题十分突出,但目前针对板块缝合带隧道的地应力研究相对较少。本文采用空心包体法对拉林铁路沿线隧道进行了原位地应力测量,并与成兰、兰渝和锦屏等几个典型工程的地应力进行对比分析。研究表明：拉林铁路沿线隧道埋深大,构造应力突出,总体表现为最大水平主应力 > 垂直主应力 > 最小水平主应力;平均侧压系数（1.0~1.5）分布较为集中且处于较高水平;最大主应力量值大多在20~50 MPa之间,最大主应力与埋深的梯度为0.033 7 MPa/m,方向以北北西-北北东向为主。建议采用仰拱结构减小隧道墙脚处的应力集中现象。     

Characterizing mixed-use buildings based on multi-source big data

To-date few research has successfully integrated big data from multiple sources to characterize urban mixed-use buildings. In this paper, we introduce a probabilistic model to integrate multi-source and geospatial big data (social network data, taxi trajectories, Points of Interest and remote sensing images) to characterize urban mixed-use buildings. The usefulness of our model is demonstrated with a case study of the Tianhe District in megacity Guangzhou, China. The model predicted building functions at 85% accuracy based on ground truth data from field surveys. We further explored the spatial patterns of the identified building functions. Most mixed-use buildings are located along major streets. Our proposed model can identify mixed-use buildings in a city; information is useful for planning evaluation and urban policymaking.     

区域性热带气旋暴雨短期预报系统在MICAPS系统上的移植

利用MICAPS系统上的实时报文资料,以物理量场诊断为动力相似的主要依据,综合热带气旋移动路径及登陆范围来订正,以人机结合方式完成梧州及贺州地区的热带气旋暴雨24h落区预报工具在MICAPS系统上的移植,直观形象地显示预报结果。该工具利用1979～1980年7～9月、1995年7～9月3a的热带气旋实例进行试报,1997～1998年7～9月试运行,均取得较好的预报效果,目前已可以在后汛期台风季节中投入准业务试用。     

内蒙古东部半干旱草原残丘景观区铜多金属元素表生地球化学异常特征及其评价指标体系的构建

分析了研究区内钙积层、风成沙等制约因素对铜多金属元素表生地球化学异常发育的影响,总结了该类特殊景观条件下铜多金属元素表生地球化学异常特征及其在垂向和侧向上的迁移规律。在此基础上,构建了该类景观区铜多金属元素的表生地球化学异常评价指标体系     

水-岩作用的线性规划模型与应用研究——以溪洛渡水电工程为例

采用水-岩作用热力学模拟的方法,以溪洛渡水电站工程为实例,从水化学方面对坝区复杂水文地质条件作了定量分析评价。研究成果充分反映了水-岩作用这种物理化学反应的结果,同时也为正确评价溪洛渡水电站复杂水文地质条件提供了可靠的依据。     

A new approach to GPS ambiguity decorrelation

Ambiguity decorrelation is a useful technique for rapid integer ambiguity fixing. It plays an important role in the least-squares ambiguity decorrelation adjustment (Lambda) method. An approach to multi-dimension ambiguity decorrelation is proposed by the introduction of a new concept: united ambiguity decorrelation. It is found that united ambiguity decorrelation can provide a rapid and effective route to ambiguity decorrelation. An approach to united ambiguity decorrelation, the HL process, is described in detail. The HL process performs very well in high-dimension ambiguity decorrelation tests. Received: 9 March 1998 / Accepted: 1 June 1999     

固体矿产钻探技术的现状和展望

分析了国际钻探市场现状以及固体矿产钻探技术的进展,归纳总结了近１０年来我国固体矿产钻探技术的主要进展,并对发展我国固体太科钻探技术提出了建议。     

24万年来西昆仑山甜水海湖岩芯碳酸盐含量变化与气候环境演化

青藏高原现代气候与环境存在着明显的区域差异。高原西北部的西昆仑山甜水 海地区是高原上气候最干旱的区域。作者于１９９５年６月在该区海拔４８４０ｍ的湖盆首次打钻取芯（ＴＳ９５孔）,获得５７ｍ湖泊岩芯,经对样品的实验室测年和多项环境指标分析,表明,ＴＳ９５孔岩芯覆盖了距今２４０－１７ｋａ间的时间尺度。期间,经历了倒数第二次冰期,末次间冰期,末次冰期早期,末次冰期间冰阶和末次冰盛期几个气候变化阶段。岩芯中