山西地震带地震活动频度特征

由一系列断陷盆地所组成的山西地震带是地震活跃的场所,了解山西地震带的活动特征,不仅对研究地震活动规律、获取信息有一定的意义,而且对山西煤炭、重化工建设也有实用价值.本文对山西地震带地震的频度特征作了探讨.试图利用不同盆地的活动图象来了解现今地震较活跃的区域,并以此确立监视的重点.     

四川省矿产资源简况

四川省的矿产资源丰富,矿种比较齐全.建国以来,已探明储量的矿种81种,其中名列全国储量前三名的有:天然气、铁、钒、钛、钴、锶、钙芒硝、熔炼水晶、光学     

山西省一次连阴雨过程分析

山西省一次连阴雨过程分析苗玉芝，任璞（山西省气象台０３０００６）１概况秋季连阴雨是常在早秋引起气温下降，造成连日持续降水的湿冷天气过程。规定：降水日数≥５天，过程雨量≥３０ｍｍ为一次连阴雨过程。１９９４年１０月１４日～２０日，我省中南部地区出现了一次...     

滇东寒武纪早期磷块岩的沉积相

本文根据近年内取得的资料,提出对滇东寒武纪早期磷块岩形成条件的认识,着重于沉积相带的划分:(1)磷块岩属半封闭海湾浅水型滨海相的潮坪沉积环境,有一系列浅水与暴露的相标志。(2)磷块岩的分布依附于沉积相。富磷矿赋存于潮间相带,而潮下“台盆”相带沉积有贫的厚层磷块岩。矿石结构既反映了沉积时水动力能量上的差异,也显示出不同的沉积环境:内碎屑结构具化学——机械特征,形成于强搅动环境中;凝胶状结构属化学沉积,形成于宁静低能环境中;球粒结构属于上两种结构的过渡产物。(3)磷块岩的岩性序列为:白云岩——磷质磷块岩、白云质磷块岩、硅质磷块岩——硅质岩。磷块岩矿床的贫富、厚薄、类型上有变化,主要反映在白云质、硅质两者配比不同。     

网页制作中元信息标记的应用

介绍了网页制作中元信息标记的功能,以及利用实现页面自动刷新、自动跳转的技巧。     

METEOROLOGICAL AND CHEMICAL CONTROLS ON THE VERTICAL DISTRIBUTION OF BEIJING SUMMER COARSE AND FINE AEROSOLS

Vertical profiles of fine and coarse aerosol particles were determined by cascade impaetors at the meteorological tower in Beijing for three days and one night, July 18-23, 1980. Coarse mode aerosols showed a maximum concentration at 47 m when there was an inversion at about 140 m height, and a rather uniform distribution when there was no inversion. This may indicate a two-component origin of coarse particles at the tower site, one being surface dust and the other being tall stack emissions. Fine mode aerosols showed more complex vertical profiles. Median particle size distributions of most metals were bimodat, indicating distinct coarse particle dispersion and fine accumulation mode processes. A chemical thermodynamfc calculation indicates that fine mode Si can result from the reduction of silica to volatile SiO during coal combustion with limited air supply, a process which should release substantial amounts of carbon monoxide to the atmosphere.     

于光远与国土经济学

于光远同志是我国著名经济学家。他不仅在经济理论学方面有许多建树,同时还创建了许多应用经济科学。如“国土经济学”就是他创建的一门重要的应用经济科学。他不单提出了国土经济学的一系列理论问题,而且还进行了大量关于国土经济学的科学实践活动。为我国国土经济学的产生和发展做出重要贡献。     

Landslide susceptibility using weights-of-evidence approach and multi-source data in Longzhong ecologically vulnerable area：a case study of Tianshui City北大核心CSCD

Analysis and assessment of landslide susceptibility using 3S technology and mathematical statistical model is still the current hot topics. It is very important for selection of unit and factor and model to the landslide susceptibility assessment reasonably. Tianshui City is selected as the study area which is in the typical regions of Longzhong ecologically vulnerable area. Based on the weights-of-evidence approach（WOE）and two kinds of assessment units（grid-unit,GU,slope-unit,SU）and also two resolutions（30 m,10 m）,a total of four differ⁃ ent data sets（GU30,SU30,GU10,SU10）is established. Then quantitative analysis and contrast assessment di⁃ vision of the loess landslide susceptibility in the study area though selected four kinds of thirteen factors. The re⁃ sults show that stratum lithology,altitude,relief amplitude,roughness and slope are the key control factors of landslide development in the area. The geological factors and topographic factors control and determine the for⁃ mation and development of the landslides in study area. The susceptibility value of stratum lithology is the high⁃ est value. Statistical analysis of susceptibility division is carried out according to the point and area of landslide respectively. The landslide ratio shows that the division based on the slope-unit is higher than that of the grid-unit. Landslide susceptibility area in highest division based on the slope-unit and 10m high resolution is account⁃ ed for the highest. Therefore,it has higher precision in landslide susceptibility analysis and assessment that us⁃ ing the slope-unit and high resolution data. The landslide susceptibility result is consistent with the actual land⁃ slide development in the study area. The division results can also be used for the landslide prevention and control and national spatial planning in the study area. © 2023 Chinese Journal of General Practitioners. All rights reserved.     

冈底斯北段赛利普组火山岩地球化学特征及地质意义

冈底斯北段赛利普组火山岩Al_2O_3、K_2O含量较高,K_2O/Na_2O比值2,TAS图解为粗安岩类,属钾玄岩系列;岩石强烈富集K、Rb、Ta、Nb、Ce等大离子亲石元素和轻稀土元素,并具明显的Ti负异常,稀土元素总量高,轻稀土强烈富集,重稀土元素亏损,Ce异常变化较大Eu变化不明显,说明岩石由岩浆与地壳经过不同程度的部分熔融作用所形成。通过采取多种测试手段及野外地质露头相互交切关系,将赛利普组形成起始时代划分为第四纪更新统时期。     

东昆仑东段金水口石榴堇青石花岗岩成因——石榴子石证据

为了查明东昆仑东段金水口地区的石榴堇青石花岗岩的成因和地质意义,对其中的石榴子石进行了岩相学和矿物化学研究。根据石榴子石的产状和成分,在该花岗岩中初略识别出岩浆型和转熔型两种成因的石榴子石。前者较少,与长石、石英共生,细小,自形,不含矿物包裹体,富MnO贫MgO,具MnO成分环带;后者较多,与黑云母共生,晶粒较大,它形,常含矿物包裹体,贫MnO富MgO,不具MnO成分环带。两种石榴子共存表明花岗岩为原地深熔成因或混合岩化成因,表明该地区的白沙河岩组片麻岩在早古生代曾经历过减压升温过程。