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61.
The significant role of transport in the development of less-developed countries is widely accepted, but the critical importance of seaports is often under-appreciated. Evidence from the Indian Ocean ports of Kenya and Tanzania is used in this paper to illustrate and support the argument that efficient port operation is an essential contributory factor in the development process.  相似文献   
62.
Summary A coupled ocean-atmosphere anomaly model has been developed for simulating ENSO cycle and its mechanism-study in this paper. After a long model run, the coupled model is successful in demonstrating ENSO-like irregular interannual variability and corresponding horizontal spatial structures. Based on the simulated results, the dynamics and the thermodynamics of the model ENSO cycle have been investigated, and in particular the negative feedback mechanisms that act to oppose instability of air-sea interaction, inducing termination of warm and cold events, have been examined. A detailed analysis of the oceanic wave dynamical properties and heat budget of the SST changes in a representative cycle suggest that the negative feedback mechanism to check the unstable growth of a warm event obviously differs from that of a cold event. The mechanism that induces decay and termination of a cold event is closely related to the negative, delayed feedback effect produced by the oceanic dynamical wave reflection at the western boundary. However, independent of the wave reflection effect, the negative feedback mechanism by which the coupled system returns from a warm event is associated with a slowly eastward-propagating coupling mode. Accompanied with the strong unstable development of the equatorial positive SST anomaly, the anomalous upwelling of cold water generated off the equator and the nonlinear anomalous meridional advection generated in the equator west of instability area jointly restrain the instability and finally plunge the system from a mature warm phase into a weak cold phase. A comparison between the results from the present model and the previous works is also discussed in this paper.With 16 Figures  相似文献   
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Barite has been found for the first time in the Swiss Jura (Hirni, Passwang). Small, white crystals of barite with yellow ankerite grow on calcite in different chambers of a Bajocian ammonite. Chemical data (by microprobe analysis) and lattice parameters (refined by leastsquares from powder patterns) are given for the two minerals. There is a distinct correlation between the cell dimensions and the chemical composition for both of them. The genesis is discussed.  相似文献   
66.
This paper examines the regional climatic and environmental changes from the late Pleistocene to middle Holocene in Central-East Asia. A review is made of the published literature that are specific to pelaeoclimate and physical environment in some geographical regions.It is shown that (1) during the late Pleistocene the annual mean temperature was 5°–6° C lower than present in Qinghai-Xizang (Tibet) plateau, 6° to 9° C lower than today in NE China, 6° C lower than today in E China, and 4° C lower than present in Taiwan island; (2) during the middle Holocene, the annual mean temperature was 4° C warmer than present in Qinghai-Xizang (Tibet) plateau, 3° to 4° C warmer than today in NE China, 2° to 3° C warmer than today in Shanghai area, and only 2° to 2.5° C warmer in Taiwan island.  相似文献   
67.
Bohra DM 《GeoJournal》1979,3(1):63-68
In this research paper attempts have been made to analyze the distribution of 68 urban settlements in 14 regions of the country. The value of near-neighbour statistic (R) shows nearly random pattern of urban settlements in some regions and approachingly uniform distribution of urban settlements in other regions. Regional distribution of urban settlements and their growth have been explained in context of region's geographical, economic and industrial frameworks.  相似文献   
68.
中国南方海相含油气保存单元的层次划分与综合评价   总被引:1,自引:0,他引:1  
以最近十年中国南方的海相新区油气勘探评价成果为依托 ,以油气成藏和整体封闭保存体系评价为核心 ,在渝东—湘鄂西、中下扬子和滇黔桂三大区域划分出 9个有利区块 5 1个含油气保存单元 ,并将其归纳为四个层次。综合评价认为 ,方西和石柱保存单元具有较好的整体封存体系 ,属持续性含油气保存单元 ,为首选勘探目标 ;江汉盆地南部、句容—海安区块、南鄱阳坳陷、楚雄盆地东北部具备或基本具备整体封存条件 ,属于沉积重建型含油气保存单元 ,通过精细勘探可望获得商业性油气流 ;楚雄盆地西北部、南盘江坳陷、十万大山盆地和渝东—湘鄂西地区利川复向斜由于晚期强烈构造改造而仅存在部分封存体系 ,需要攻关探索 ;思茅、渝东—湘鄂西地区的花果坪和桑植—石门地区已失去整体封闭保存条件 ,仅局部存在封存体系 ,地质条件高度复杂 ,勘探风险甚高。  相似文献   
69.
Summary The Alcsutdoboz-2 (AD-2) core contains 12 magmatic dykes which belong to the Late Cretaceous lamprophyric-carbonatitic association of NE Transdanubia, Hungary. Petrographically, 11 dykes can be considered alkaline lamprophyre (mainly monchiquite), and the remainder might be called carbonatite. The lamprophyre dykes are similar to both alkaline lamprophyres and ultramafic lamprophyres in major element composition, whereas the carbonatite dyke has some features that are similar to carbonatites but others that are dissimilar. Nevertheless, both of the two types of AD-2 dykes possess higher LILE content than the ultramafc lamprophyres and kimberlites, but strongly differ from average carbonatite. Based on the REE pattern, crystal fractionation (mainly of olivine) and separation of a carbonate phase from the parental lamprophyric magma are proposed for genesis of the carbonatite dyke. These characteristics and the compositional zoning of clinopyroxene and mica suggest a complex crystallization history for these dykes. The likeliest origin for the parental lamprophyric melt is through a very small degree of partial melting of metasomatized mantle.
Alkalische Lamprophyre und assoziierte Ganggesteine in Nordost-Transdanubien, Ungarn: die Bohrung Alcsutdoboz-2 (AD-2)
Zusammenfassung Der Kern der Bohrung Alcsutdoboz-2 (AD-2) enthält zwölf magmatische Gänge, die zu der jung-kretazischen Lamprophyr-Karbonatit-Assoziation des nordöstlichen Transdanubiens in Ungarn gehören. Petrographisch gesehen gehören elf Gänge zu den alkalischen Lamprophyren (hauptsächlich Monchiquit), und der Rest kann als Karbonatit bezeichnet werden. Die Lamprophyrgänge sind in ihrer Hauptelementzusammensetzung sowohl alkalischen Lamprophyren wie ultramafschen Lamprophyren ähnlich. Der Karbonatitgang hingegen zeigt Parameter, die denen von Karbonatiten teilweise, aber nicht durchwegs, ähnlich sind. Beide Typen der AD-2-Gänge zeigen höhere LILE-Gehalte als ultramafische Lamprophre und Kimberlite, unterscheiden sich aber deutlich vom durchschnittlichen Karbonatit. Auf der Basis der Seltenen ErdVerteilung, werden Kristallfraktionierung (hauptsächlich von Olivin) und Abtrennung einer Karbonatphase von lamprophyrischen Magma als Vorgänge gesehen, die für die Entstehung der Karbonatit-Gänge relevant sind. Diese Aspekte und die Zonierung der Zusammensetzungen von Klinopyroxen und Glimmer weisen auf eine komplexe Kristallisationsgeschichte dieser Gänge hin. Sehr wahrscheinlich ist die lamprophyrische Ausgangsschmelze durch eine geringfügige teilweise Aufschmelzung von metasomatisiertem Mantel entstanden.
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70.
Zusammenfassung Die alpine Krustenverkürzung (300–400 km oder mehr im Profil der Westschweiz, 400–500 km oder mehr im Profil der Ostschweiz) erfolgte in diskreten orogenen Phasen, welche durch Zeiten langsamerer Bewegung oder eigentlicher Remission getrennt waren. Während der wichtigsten Phase, an der Eozän-Oligozän-Wende, betrug die Relativgeschwindigkeit der nördlichen Platte und der südlichen Kleinplatte einige cm/a.
Crustal shortening in the Central Alps (300–400 km or more in western Switzerland, 400–500 km or more in eastern Switzerland) occurrend in discrete orogenic phases, separated by times of slower movement or of complete stop. During the most important phase, at the turn from the Eocene to the Oligocene, the rate of relative movement of the northern plate and the southern microplate was of the order of several cm/y.

Résumé Le raccourissement de la croûte dans les Alpes Centrales (300–400 km ou davantage en Suisse occidentale, 400–500 km ou davantage en Suisse orientale) se fit par phases orogéniques défines, séparées par des intervalles à mouvement plus lent ou même à arrêt total. Pendant la phase principale, à la fin de l'Eocène ou au début de l'Oligocène, la vitesse relative de la plaque septentrionale et de la microplaque méridionale était de l'ordre de plusieurs cm/a.

(300–400 , , 400–500 , ) , , . , - , /.
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