天然水中氚的测定方法     

林瑞芬卫克勤  王洪波 《地球化学》1979,(4):347-352

Recommended in this paper is a routine, but improved analybical method for measuring tritium in precipitation aud surface water samples. The measurement of tritium radioactivity is performed on a China-made FJ-353 Model Liquid Scintillation Spectrometer, involving electrolytical concentration with the volume eoncentration by a factor of 100, in conjunction with a liquid scintillation counter. By using the improved distilling apparatus- the sealed low-pressure distillator, the advantage of simplibility in operation is expected in purifying the concentrated water sampIes. The comparison of dioxane scintillator solution with Triton-X-100 emulsion scintillator solution has been made, showing that for the dioxane system, a 17 ml sample contains 3 ml water with the background of 12 cpm and efficiency of 22%, corresponding to 210 TU/cpm, and for the Triton-X-100 system, a 17 ml sample containing 5 ml water has the background of 12 cpm and efficiency of 18%,equivalent to 150 TU/cpm. Furthermore, a brief account has also been given of the process in tritium measurements by way of synthesizing benzene from water with SiO2Al2O3-Cr^ 6 as catalyst without concentration treatment.  相似文献   

地洼区原生金矿的某些成矿特征     

卫万顺 《黄金地质科技》1989,(2):41-50

  相似文献   

农业与气候     

内岛善兵卫  章庆辰  高素华 《沙漠与绿洲气象(新疆气象)》1986,(1)

前言农业生产和气候的关系,历来各国都认为是最重要的.作为主要粮食的谷类作物,在广大地区栽培、生产,但对这些地区的气象环境,很难进行人为的改变.作物的每个生长区域,也都有其不适应性,而阻碍了作物的生长、发育,甚至减产.由于气象、气  相似文献   

太白—镇平一带古板块构造及其卡林型金矿     

卫万顺 《黄金地质》1987,(3)

太白—镇平一带地处塔里木—中朝板块和华南—中南板块之间,属秦祁昆构造域的一部分,是卡林型金矿产出的重要地带。所谓卡林型金矿是指由地下热卤水的循环溶滤作用,沿构造窗、层间破碎带和构造裂隙而形成的微细浸染型金矿床。  相似文献   

西藏羊八井地热水的氢、氧稳定同位素组成及氚含量   总被引：4，自引：0，他引：4  

卫克勤林瑞芬  王志祥 《地球化学》1983,(4):338-346

Isotopic data on drill hole water and surface water samples from the Yengbajain geothermal area as well as an ice sample from the glacial amphitheater in the Mt. Nyainqintanglha to the northwest of the Yangbajain basin are presented in this paper. In consideration of isotopic fractionation during steam separation, the hydrogen and oxygen isotopic ratios for thermal waters collected at the mouths of drill holes have been calibrated. The D/H ratio of thermal waters is similar to that of local precipitation, indicating their meteoric origin. The δ D and δ^18O values of the thermal waters of --150--160 and -17-20‰, respectively are the lowest among those well-known geothermal fields in the world.The recharge area of the geothermal system is at elevation of about 4,800--5,000 m. Drill holes along the axis of a tongueshaped zone where loose Quaternary sediments have been cemented by siliceous material show greater δ D and δ^18O values and discharge tritiumfree thermal waters. It is suggested that the thermal waters may be derived from superhcated water and steam which find their way upwards along the tectonic fractures within the granitic base overlain by Quaternary sediments. The classification of drill hole geothermal waters have been made in accordance with their δ D and δ^18O values and chloride contents. The “oxygen shift” of the thermal waters seems to be 2‰, due to isotopic exchange reactions between geothermal waters and reservoir rocks  相似文献   

用周期分析方法预测全球稻谷总产量   总被引：2，自引：0，他引：2       下载免费PDF全文

李军  杨星卫  汪治澜 《气象》1997,23(7):32-34

应用功率谱和逐步回归周期分析方法对全球稻谷总产量预测进行了探讨，结果表明逐步回归周期分析方法具有很好的拟合精度和较高的预测精度。  相似文献   

地理环境和服饰     

卫杰文 《地理教学》2001,(4):7-8

各具特色的地理环境，在人们的服饰上留下了独特的乡土风情。复杂多样的气候，孕育了绚丽多姿的民族服饰。简便的草裙与炎热的气候相关联，丰厚的皮服与严寒的气候相伴随。地理环境的差异导致服饰的多样。  相似文献   

桑树坪煤矿3号煤层层滑构造发育特征   总被引：1，自引：0，他引：1  

陈练武  卫兆祥 《西北地质》1997,18(4):58-61

本文以桑树坪煤矿3号煤层中揭露的层滑构造为基础，分析了3号煤层中层滑构造的主要表现形式和对煤矿生产的影响，探讨了该区层滑构造形成的主要机理，指出了层滑构造的发育部位和主要滑动方向。  相似文献   

关于黑色页岩矿床成因的一组论文   总被引：1，自引：0，他引：1  

卫三元  李田港 《国外铀金地质》1997,14(3):233-234,246

本文比较系统地介绍了黑色页岩与金属成矿关系的各个侧面。通过评述有关黑色页岩的９篇文章，对黑色页岩的形成环境，成岩方式及对世界上一些著名的金矿床，如密西西比河谷型硫化物矿床，南非兰德铀金矿床的成因提出了新的观点。  相似文献   

非正常情况下北京城市地质安全危机管理的战略思考     

卫万顺 《城市地质》2007,2(4):1-4

为了保证北京城市可持续发展，必须解决可持续发展面临的特殊挑战，有必要进行非正常情况下北京城市地质安全危机管理的战略思考。本文探讨了我市非正常情况下城市地质安全危机管理战略框架，建议制定《非正常情况下城市地质安全危机管理应急预案》和实行定期会商机制，建立完善的监测预警预报系统，实施城市地质安全保障工程，促进首都经济建设和社会可持续发展。  相似文献