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11.
River basins are an extremely important source of freshwater for Africa and the impact of climate change on these communities constitutes an important question worth studying. Among these basins, the Niger River Basin is an ideal candidate for meso-level theory testing of climate change-induced political violence because of its importance as one of the largest sources of freshwater in Africa, its high vulnerability to climate change, and its location in a politically unstable region. This paper utilizes the benefits of GIS to test whether effects of water insecurity on the various incidences of political violence are conditional on economic, geographic, and social means of connectivity. Our analysis uses the density of secondary road networks, the geographic distance to the Niger River, and a shared co-ethnicity with one's head-of-state to evaluate the impact of hydrological stress and its subsequent risk for political violence across nine West African countries from 1997 to 2012. Using climatological data and an econometric de-trending method, we measure the separate, substantive impact that individualized changes in precipitation trend and precipitation variability have for the incidence of ACLED's political violence events, conditional on local economic, geographic, and social factors. Our results reveal a complicated web of circumstances under which certain forms of political violence are more/less likely to be observed. The implications of this analysis serve as a call for a closer inspection of the micro-channels by which climate stress impacts heterogeneous communities in the developing world.  相似文献   
12.
    
Investigations at the Carson site (22CO505), located in Coahoma County, Mississippi, have uncovered data on the development of a large Mississippian mound center dating to the period from A.D. 1200 through European contact. Recent sediment coring, excavation, artifact analyses, and radiocarbon and optically stimulated luminescence (OSL) dating shed light on earthworks and household structures at Carson, and on Mississippian culture in the Yazoo Basin more generally. Sediment coring demonstrates a laterally transgressing Mississippi River system deposited coarse sandy ridges and clay-filled swales underneath a surface horizon comprised of variously coarse to medium-fine sediment originating from generalized overbank flooding. In some instances, flood-borne sediments were found on mound flanks, indicating that at times river-based flooding may have interrupted mound construction. Sediment coring and trench excavation also demonstrate that Carson’s Mound D was built in four stages, with Stages II and III comprising the major stages of earth moving. Excavations on the mound summit reveal evidence of several superimposed structures that were burned in place and likely used for the production of stone, shell, and wooden craft items, perhaps related to Mississippi Ideational Interaction Sphere (MIIS) paraphernalia. Here we describe recent investigations at Carson and present preliminary findings; forthcoming publications will emphasize strategies of power, monumentality, craft production, and Mississippian exchange systems.  相似文献   
13.
    
In Pincevent (Paris Basin), archeaozoologists have observed a variation of hunting strategies between Magdalenian levels IV0 and IV20. Previous works on human‐prey interaction showed that hunters modelled their behaviour on their prey; therefore, re constructing animal behaviour in order to reconstruct human strategies could enable better interpretation of these levels. This study aims to contribute to a global understanding of the variation between these level's hunting strategies using microwear texture analysis. This proxy, which can be used to reconstruct diet, will enable to detect changes in the behaviour pattern of the prey. The decision was made to focus this study on reindeer (Rangifer tarandus) as it was one of the two most exploited resources on this site, alongside horses. The enamel surface of teeth from two populations of reindeer, hunted and found in levels IV0 and IV20, showed a variation of diet between levels. Environmental and ecological matters are discussed with an aim to understanding this variation of behaviour in reindeer populations and highlight a change of strategic behaviour among hunters.  相似文献   
14.
    
Lions reached their northernmost distribution in the Carpathian Basin at a time when the climate turned cooler and drier and the complex Late Neolithic settlement network, marked by human populations concentrated on and around tells, disintegrated. A perforated distal phalanx and a calcaneus of lion (Panthera leo L., 1758) from two different Copper Age (5th–4th millennium cal BC) settlements in Hungary contribute to mapping the distribution of Holocene lions in southeast Europe. Previous discoveries of lion bones (representing all parts of the body) have offered evidence of local lion hunting and probable consumption. The new finds also illustrate the cognitive significance of lions and help reconstruct their phenotypic size. The perforated phalanx discussed in this paper represents the large dewclaw of a powerful male, the first ever worked lion bone available in Hungary. The calcaneus offers additional metric information interpreted in light of measurements taken on extant individuals from both Asia and Africa. Inseparable environmental and cultural factors leading to the occurrence and extinction of prehistoric lions in the Carpathian Basin are reviewed in light of these new data.  相似文献   
15.
在地理环境相对封闭的楠溪江流域,以血缘宗族为纽带沿江分布的古村落群,在宋代已经形成了基本的格局。发展至今,多数古村落已绵延数百年,创造出了独具特色的宗族文化。在流域宗族文化形成的同时,学术文化也迅速发展,至宋时达到高峰,出现了文化繁荣、政治显赫的时代,形成永嘉事功学派。  相似文献   
16.
    
Earliest Triassic shales in the Coal Cliff Sandstone, Caley Formation, Widden Brook Conglomerate and Dooralong Shale (all basal Narrabeen Group) of the Sydney Basin contain a low diversity fossil flora that survived the greatest mass extinction of all time at the Permian-Triassic boundary. Only one species of seed fern is known from this flora and its affinities were unclear until discovery of its reproductive organs and complete large leaves. An ovuliferous reproductive organ, Peltaspermum townrovii sp. nov., can be attributed to the same plant as the leaves because of their identical stomatal apparatus, which is cyclocytic with papillae overhanging the stomatal pit. Polleniferous organs, Permotheca helbyi sp. nov., may have belonged to the same plant, but are only linked by evidence of association on the same bedding plane yielding no other gymnosperms. Pollen masses found within the polleniferous organ include grains identified as Falcisporites australis (de Jersey) Stevens (1981) when found dispersed. The leaves of this plant have long been enigmatic and attributed to ‘Thinnfeldia’ callipteroides or ‘Dicroidium’ callipteroides; however, these genera had very different cuticular structure. Reassessment of the frond architecture of this plant, based on a large, nearcomplete specimen together with information from cuticles and ovuliferous organs, allows reassignment to Lepidopteris callipteroides (Carpentier) comb. nov. The remarkable cuticle thickness, small stomatal size and low stomatal index of these leaves reflect a time of unusually high atmospheric concentrations of carbon dioxide. This plant was an invader of the Sydney Basin from northern Gondwana, spreading southward during the post-apocalyptic earliest Triassic greenhouse.  相似文献   
17.
    
Over 50 identifications of Tertiary pollen are reviewed. The pollen assemblages indicate rain-forest through most of the Tertiary, but the requisites for pollen preservation are biased towards the wetter climates.

The present day geographical affinities of the botanical groups are largely with taxa of the tropical zone and Australia-wide taxa. There is geographic variation in the fossil pollen assemblages when southeastern Australia is compared with Central Australia and Queensland.

The major changes in the fossil floras coincide with climatic change, indicating the influence of climate on the evolution of plant assemblages. The older phytogeographic concepts are inappropriate for the fossil record, especially when considered in conjunction with palaeoclimates and palaeogeography.

It is unfortunate that palynology has given little information of the evolution of floras in drier climatic regimes, or of the evolution of the eucalypts.  相似文献   
18.
    
A new temnospondyl from the Early Triassic Buena Vista Formation (Paraná Basin) in Uruguay is described. The specimen is represented by a skull table fragment which includes the left orbit, and, although fairly incomplete, shows close affinities with the basal temnospondyl clade (Dvinosaurus + Tupilakosauridae). Previously, members of this clade were only known from Upper Permian and Lower Triassic deposits from the Northern Hemisphere. The new specimen described herein together with a recent record from the Lower Triassic of South Africa (Karoo Basin), support the hypothesis of an invasion of members of the basal (Dvinosaurus + Tupilakosauridae) clade into Gondwana as early as the Late Permian.  相似文献   
19.
The brissid echinoid Schizobrissus insignis (Duncan &; Sladen, 1883) is described from the Fulra Limestone (late middle Eocene), in Kachchh, India. Formerly assigned to Peripneustes or to Meoma it is shown that the species possesses a complete subanal fasciole throughout ontogeny, a characteristic feature of Schizobrissus. Eocene species of Schizobrissus and Meoma show several morphological similarities, but diverged during the late Paleogene and early Neogene.  相似文献   
20.
    
Two associated anterior dorsal vertebrae of a primitive archosaur are described from the Early Triassic (Dienerian–Spathian) Bulgo Sandstone at Long Reef, New South Wales, Australia. Character states including anteroposteriorly elongate centra, dorsal neural spines with height greater than length, the possible presence of intercentra, double-headed rib articulations and well-developed apical tables on the neural spines suggest affinity with proterosuchid archosauriforms and permit some comparisons with previously described Australian taxa. The Bulgo Sandstone vertebrae represent the first record of archosaurian body fossils from the Sydney Basin and are one of only a handful of occurrences thus far documented from the Triassic of Australia.  相似文献   
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