A sociodemographic typology of middle-level regions in the USSR     

Fedorov GM 《Soviet geography》1983,24(4):289-297

"Oblast-level regions of the USSR are grouped and mapped in nine types and a number of subtypes to reflect a combination of demographic factors: level of urbanization, urban and rural population growth, and population density. The typology can be used to devise sets of spatially differentiated measures to carry out a demographic policy and to regulate the sociodemographic evolution of regions."  相似文献   

Sediment oxygen profiles in a super-oxygenated antarctic lake     

Wharton RA  Meyer MA  McKay CP  Mancinelli RL  Simmons GM 《Limnology and oceanography》1994,39(4):839-853

Perennially ice-covered lakes are found in the McMurdo Dry Valleys of southern Victoria Land, Antarctica. In contrast to temperate lakes that have diurnal photic periods, antarctic (and arctic) lakes have a yearly photic period. An unusual feature of the antarctic lakes is the occurrence of O2 at supersaturated levels in certain portions of the water column. Here we report the first sediment O2 profiles obtained using a microelectrode from a perennially ice-covered antarctic lake. Sediment cores collected in January and October 1987 from Lake Hoare in Taylor Valley show oxygenation down to 15, and in some cases, 25 cm. The oxygenation of sediments several centimeters below the sediment-water interface is atypical for lake sediments and may be characteristic of perennially ice-covered lakes. There is a significant difference between the observed January and October sediment O2 profiles. Several explanations may account for the difference, including seasonality. A time-dependent model is presented which tests the feasibility of a seasonal cycle resulting from the long photoperiod and benthic primary production in sediments overlain by a highly oxygenated water column.  相似文献   

Integrated chemostratigraphy and biostratigraphy of the Windermere Supergroup, northwestern Canada: implications for Neoproterozoic correlations and the early evolution of animals     

Narbonne GM  Kaufman AJ  Knoll AH 《Geological Society of America bulletin》1994,106(10):1281-1292

The thick, richly fossiliferous succession of the upper Windermere Supergroup, Mackenzie Mountains, northwestern Canada, provides a test of integrated biostratigraphic and chemostratigraphic frameworks in terminal Proterozoic correlation. The C- and Sr-isotopic abundances of lower Keele Formation carbonates approximate those for other pre-Varanger samples, confirming that the simple disc-like fossils of the underlying Twitya Formation predate all known diverse Ediacaran faunas. "Tepee" and Sheepbed carbonates record strong post-glacial isotopic excursions; in contrast, delta13C values for Gametrail through Risky carbonates vary only within the narrow range of about +l% to +2%. A second negative excursion occurs in Ingta Formation carbonates that immediately underlie the paleontologically determined Precambrian-Cambrian boundary. The upper Windermere profile as a whole compares closely with curves determined for other terminal Proterozoic successions. The lowermost diverse Ediacaran assemblages in the Sheepbed Formation correlate chemostratigraphically with the oldest fauna in Namibia, but the two assemblages differ in taxonomic composition. Blueflower assemblages correlate both chemostratigraphically and taxonomically with faunas from Australia, China, Siberia, and elsewhere. Increasing data support the hypothesis that paleontological and geochemical data together provide a reliable means of correlating terminal Proterozoic sedimentary rocks throughout the world.  相似文献   

爱尔兰克朗提布伦特奥陶纪硬砂岩中的金矿比     

斯蒂.  GM 郝梓国 《国外矿床地质》1991,(1):27-48

  相似文献   

魏格纳     

肖承邺  杨宝仁  刘新美 《山西地震》1985,(1)

魏格纳是德国人,1880年11月1日出生在柏林.魏格纳年青时在大学里攻读天文学和气象学,1905年获博士学位.1906年他应邀参加丹麦探险队,前往北极圈内的格陵兰探险,其间还参加乘气球远航的飞行,并创造了连续飞行52小时的当时世界纪录.回国后,任德国马尔堡大学天文学和气象学讲师.1924年应聘任奥地利格拉茨大学大气与地球物理学教授.  相似文献   

傅承义(Fu Cheng-yi)     

肖承邺  杨宝仁  刘新美 《地震地磁观测与研究》1985,(2)

地球物理学家、中国科学院地学部委员傅承义先生,1909年10月7日出生于福建省闽侯县。傅承义先生1933年毕业于清华大学物理系,留校任教七年,于1940年赴加拿大和美国留学,1941年获加拿大麦吉尔大学物理学硕士学位,1944年获美国加利福尼亚州理工大学地球物理学博士学位,1947年5月回国。解放后,傅承义先生一直在中国科学院地球物理研究所任研  相似文献   

John Milne(米尔恩)     

肖承邺  杨宝仁  刘新美 《山西地震》1984,(3)

地震学家、地质学家米尔恩是英国人,于1850年12月30日出生在英国利物浦。米尔恩青年时代在英国皇家矿业学院学习地质和矿物学。1875年,英国政府派他作为英国专家组的地质学家,去日本协助指导矿山工作。1876年,日本政府聘请他担任东京工程学院地质学和矿物学教授,后又被东京帝国大学任命为世界上第一位地震学教授。1895年7月米尔恩结束了在日本的工作,回国后继续地震研究工作和社会活动,并被英国不列颠科学促进协会任命为地震学研究委员会干事。  相似文献   

李四光(Li Sukuang)     

杨宝仁 《地震地磁观测与研究》1984,(4)

地质学家李四光是中国科学院地学部学部委员,1884年10月26日出生于湖北黄冈县回龙山镇。李四光1905年去日本留学,1912年又前往英国伯明翰大学地质系留学,学习采矿和地质,1919年获该大学学士和硕士学位。1920年受聘任北京大学地质系教授,主讲岩  相似文献   

Oxygen budget of a perennially ice-covered Antarctic lake     

Wharton RA  McKay CP  Simmons GM  Parker BC 《Limnology and oceanography》1986,31(2):437-443

A bulk O2 budget for Lake Hoare, Antarctica, is presented. Five years of seasonal data show the lake to be persistently supersaturated with O2. Oxygen is carried into the lake in glacial meltstreams and is left behind when this water is removed as ice by ablation and sublimation. A diffusive loss of O2 from the lake through the summer moat is suggested. Measured values of the total O2 in the water column indicate that the time scale of O2 turnover is much longer than a year. Based on these results we suggest that the amount of O2 in the water does not change significantly throughout the year and that the lake is also supersaturated with N2.  相似文献   

根据宽频带P波波形快速确定Mω     

Tsuboi  S 杨宝仁 《世界地震译丛》1996,(4):62-69

本文通过对发生在日本及其周围５￣７级地震的宽频带地震图的分析，发展通过对初至Ｐ波波形确定矩震级的技术，理论上我们把在宽频带地震仪记录的Ｐ波段位移作为一个挖的源时间函数，并对其积分，得到在每个台站的标量矩。我们的结果表明，对多道记录的组合，能在没有进行震源机制校正的情况下给出一个好的矩震级估计值，这个技术相当简单和稳健，因此，它将有效地对大地震可能引起的海啸进行快速评定。  相似文献