Distribution of <Superscript>226</Superscript>Ra in the Arctic Ocean and the Bering Sea and its hydrologic implications

Radium-226 (²²⁶Ra) activities were measured in the surface water samples collected from the Arctic Ocean and the Bering Sea during the First Chinese National Arctic Research Expedition. The results showed that ²²⁶Ra concentrations in the surface water ranged from 0.28 to 1.56 Bq/m³ with an average of 0.76 Bq/m³ in the Arctic Ocean, and from 0.25 to 1.26 Bq/m³ with an average of 0.71 Bq/m³ in the Bering Sea. The values were obviously lower than those from open oceans in middle and low latitudes, indicating that the study area may be partly influenced by sea ice meltwater. In the Bering Sea, ²²⁶Ra in the surface water decreased northward, probably as a result of the exchange between the ²²⁶Ra-deficient sea ice meltwater and the ²²⁶Ra-rich Pacific water. In the Arctic Ocean, ²²⁶Ra in the surface water increased northward and eastward. This spatial distribution of ²²⁶Ra reflected the variation of the ²²⁶Ra-enriched river component in the water mass of the Arctic Ocean. The vertical profiles of ²²⁶Ra in the Canadian Basin showed a concentration maximum at 200 m, which could be attributed to the inputs of the Pacific water or/and the bottom shelf water with high ²²⁶Ra concentration. This conclusion was consistent with the results from ²H, ¹⁸O tracers.     

Basic characteristics of active tectonics of China

Active tectonics is inferred to all the structures which have been active since the late Pleisto-cene, 100—120 ka B.P., are still active recently, and will be active in a certain time period in the future, such as active faults, active folds, active basi…     

Statistical models for the assessment of nitrate contamination in urban groundwater using GIS

The purpose of this study is to develop statistical models for groundwater quality assessment in urban areas using Geographic Information Systems (GIS). To develop the models, the concentrations of nitrate (expressed as nitrogen, NO₃-N), which are different according to the type of land use, well depth and distribution of rainfall, were analyzed in the Seoul (the capital of South Korea) area. Data such as land use, location of wells and groundwater quality data for nitrate contamination were collected and a database constructed within GIS. The distribution of NO₃-N concentrations is not normal, and the results of the Mann-Whitney U-test analysis show the difference of NO₃-N concentration by well depth and by distribution of rainfall. In both the shallow and deep wells, the radius of influence is 200 m in the dry season and 250 m in the rainy season, showing the tendency to increase in the rainy season. The results of correlation and regression analysis indicate that mixed residential and business areas and cropped field areas are likely to be the major contributor of increasing NO₃-N concentration. Land uses are better correlated with NO₃-N in deep wells than in shallow wells.     

鞍山汤岗子地热田控热构造分析

汤岗子地热田受活动性深断裂寒岭壳断裂的控制.地热田包括东、西两个热储,其储热构造走向相近,而倾向相反,构成陡倾斜反"S"型构造.区域构造、导热构造和储热构造,在平面展布上呈"F"形.     

Spatial and temporal trend of sewage pollution indicated by coprostanol in Macao Estuary,southern China

Bottom sediments and a ²¹⁰Pb dated sedimentary core in Macao Estuary were quantitatively analyzed with GC-MS for coprostanol and other sterols. Higher coprostanol concentrations were detected at Port Interior and Lower Qianshan River, indicative of serious sewage pollution from densely populated Macao Island and Zhuhai City. However, very low concentrations of coprostanol were detected around Coloane Island as well as Port Exterior and Maliuzhou River except sites adjacent sewage outlets. Coprostanol pollution in Macao Estuary originates mainly from locally direct discharge of untreated wastewater. The concentrations of coprostanol in ZJ-9 were mainly in range of 150–280 ng/g with an average of 210 ng/g for more than 20 years from early 1970s to early 1990s. However, it increased obviously since 1993, and reached the highest in 1995–1996. However, a sharp decrease of coprostanol concentration from 470 to 31 ng/g after 1996 was observed corresponding to the first wastewater treatment plant in Taipa Island going into action.     

论中国东部大型盆地区及邻区地质-地球物理复合尺度解析

作为对中国东部陆缘地带大型盆地区及邻区地质－地球物理综合研究的部分结果,本文的基本认识：（1）穿过松辽盆地的1孙吴－双辽断裂可能是东倾伯低角度壳内断裂;（2）松辽盆地和渤海湾盆地可能属于“混合型裂谷盆地”;（3）东海盆地台北坳陷处在多期次张性应力场环境中,使在其西部附近产生张性正断层系;（4）欧亚大陆东部新生代区域构造运动总体处于右旋走滑拉张环境,其动力因素包括板块运动和地幔物质运动;（5）研究区莫霍面具有较为复杂的变化;（6）复合尺度研究方法是地质－地球物理综合分析的必要手段。     

地理坐标下网格化数据等值线的处理及编程

分析了均匀网格化数据等值线处理的具体步骤 ,介绍了非均匀网格分布数据的均匀网格化处理中的 3种方法 :按距离加权的最小二乘法 (N— P法 )、按方位取点加权法和加权最小二乘法拟合法 (M— S法 ) ,提供了 N— P法和 M— S法的 C 源程序     

中南半岛影响南海夏季风建立和维持的数值研究

利用美国大气研究中心研制的第三代公共气候模式(CCM3)模拟了中南半岛对南海夏季风的建立和维持的影响,数值试验结果表明,中南半岛对南海夏季风的建立和维持起了非常重要的作用.同时还就中南半岛影响南海夏季风建立和维持的机制进行了讨论.     

城市虚拟现实研究初探

虚拟城市是 3维城市地理信息系统的前沿领域 ,该文对在微机上如何建立虚拟城市作了初步探讨 ,把建立虚拟城市的方法分为 3维真实场景建模、海量数据环境下的场景漫游以及确定任意时刻声音文件的调入时机三个部分。重点介绍了控制三维场景漫游、自适应层次细节模型、简单碰撞检测的实现方法 ,并提出了采用泰森模型调用声音文件的新思路。最后给出在VC 开发环境下用OpenGL建立虚拟城市的应用实例。     

谭庄水库供水工程自控管理系统的研发与应用

为确保聊城热电厂新扩建2×300MW机组用水和满足东昌湖水位稳定要求,谭庄水库工程控制系统采用先进的DCS控制系统和无线数据通讯方式,结合工程运行要求,在设备保护、闸门控制、水位(流量)测控、管路渗漏检测、远程数据传输等环节,采用了科学先进的系统控制策略和控制方式,不仅提高了整个水库运行管理的自动化水平,并首次对15公里外的东昌湖水位实行了实时监测和调节控制,充分保障了"江北水城"水环境的特殊要求.