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1.
A problem which has arisen in discussions of an elm-disease explanation for the Neolithic elm decline has been the lack of fossil records of Scolytus scolytus (F.) (elm bark beetle), which is the main carrier of the fungus which causes the present epidemic of Dutch Elm Disease. Now, the discovery of wing cases of two individuals from elm decline deposits at Hampstead Heath, London, proves that the beetle was present in Britain during this episode. The deposits in which it occurs are described, and the various implications for elm disease causing, aiding or at least occurring during this stage of the early Neolithic are discussed.  相似文献   
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The soluble and exchangeable ions for a soil profile from the Roonka archaeological site. Lower Murray Basin, South Australia, are compared with the total elemental content of the soils. Since the chemical composition of post-mortem ionic substitution phases and secondary minerals in archaeological bone will depend on the availability of ions to the soil solution under field conditions, it is suggested that models addressing diagenesis in bone employ soluble and exchangeable ions rather than total elemental soil data.  相似文献   
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ABSTRACT

Fungal spores and other ‘non-pollen palynomorphs’ are an overlooked and valuable analytical resource available to palaeoecologists and archaeologists as part of a multi-proxy dataset. Both complementary and antagonistic data gleaned from these analyses are useful for making inferences concerning past human behaviour, as anthropic activity may have many microbotanical correlates. The use of fungal spores in palaeoecology and archaeology is reviewed, followed by analysis of pollen, fungal spores, and microcharcoal from a sediment core collected at Mtwapa Creek, Kenya. These proxies are analysed against palaeoclimatic data from the region in order to identify unexpected patterns and hypothesise as to possible scenarios which might have created them, and conclude with suggestions for further research.  相似文献   
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Economic globalisation has led to a huge increase in demand for food, goods and services by expanding urban middle class populations. These demands cause environmental changes that in turn feed back upon the urban environment and human population. While the global changes are well researched, the cumulative significance of local environmental changes is less well known. Yet, the local changes may have greater impact on the decisions which individuals make that affect soil erosion and land degradation. People respond to family circumstances and to local economic opportunities in ways that most suit the needs of their families and households. Several demonstration projects that were not adopted offer lessons in understanding how people make their land‐use decisions. An understanding of people's past experiences, present needs and views of the future helps those seeking to improve environmental management to promote policies and actions that are likely to succeed by being acceptable to those involved.  相似文献   
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To help improve the well‐being of the local people, a joint Vietnamese‐UK team set out to establish a way of estimating soil and nutrient losses under different land management scenarios, using field data extrapolated through remote sensing and GIS, to obtain catchment‐wide estimates of the impact of land cover change. Immigration from remote provinces to the Dong Phu District of Binh Phuóc Province, about 120 km north of Ho Chi Minh City, has led to disruption of soil surface stability on easily eroded clayey sandstones, creating rapid nutrient depletion that affects crop yields and siltation in the channel of the Rach Rat river downstream. The poor farmers of the areas see crop yields drop dramatically after two or three years of cultivation due to the fertility decline. Soil loss varies dramatically between wet season and dry season and with ground cover. Erosion bridge measurements showed a mean loss of 85.2 t ha?1 y?1 under cassava saplings with cashew nuts, 43.3 t ha?1 y?1 on uncultivated land and 41.7 t ha?1 y?1 under mature cassava. The rates of erosion were higher than those reported in many other parts of Vietnam, reflecting the high erodibility of the friable sandy soils on the steep side‐slopes of the Rach Rat catchment. However, although the actual measurements provide better soil loss data than estimates based on the parameters of soil loss equations, a large number of measurement sites is needed to provide adequate coverage of the crop and slope combinations in this dissected terrain for good prediction using GIS and remote sensing.  相似文献   
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A simple scheme for soil sampling and subsequent analysis for total soil phosphorus using perchloric acid digestion is described and its application illustrated by samples from the native farmstead of the Roman period at Cefn Graeanog in North Wales. The floor deposits of three distinctive buildings were analysed, and the data obtained enhanced by Trend Surface Analysis to produce generalized maps of the phosphorus distribution, together with levels of significance of such distribution patterns. These were then used to clarify the details of the interpretation of the usage of the various types of building. Data for soil phosphorus concentration clearly reveal the pattern of erosion of constructed floors, the presence of features such as hearths and drains, and can be used to reveal patterns not otherwise discernible by excavation techniques.  相似文献   
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James Arthur Prescott was a prominent soil scientist whose career responded to an increasingly complex, recognisably Australian web of interpenetrating spatial scales, served to promote revolutionary global advances in his chosen field, and in the process negotiated the blurred boundaries between ‘pure’ and ‘applied’ research. Encounters with this instructive life suggest that, while resolutions of pivotal anxieties might turn on ineluctably personal qualities, they also reflect a dynamic interplay between international, imperial, national and state contexts. Prescott's innovative contributions to soil science, fruits of a tenaciously consolidated career, influenced resource appraisal and environmental management across a prodigious continental expanse. A sustained focus on local and regional development brought him into contact with a wide range of contemporaries, including pioneering geographers, and culminated in his election to a Fellowship of the Royal Society.  相似文献   
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South‐western Australia is a globally significant hotspot of Proteaceae diversity. This review reports on changes in the abundance and diversity of Proteaceae in south‐western Australia. Using palynology, the data were obtained from three sediment sequences from the Eocene, Pliocene and Holocene, as well as a modern pollen rain study, in the context of a vegetation history framework. The total percentages of Proteaceae pollen in pollen counts indicate that the number of Proteaceae in the vegetation are highest at present, slightly lower, yet still high in the Eocene, reduced by the Pliocene and lowest in the Holocene. It was found that Proteaceous genera can contribute up to 50% of the total modern pollen rain. Sediment from Lake Lefroy showed Nothofagus‐dominated rainforest occurred in the Middle to Late Eocene. Proteaceae species were at least as diverse as today, contributing up to a maximum of 42% of the total pollen rain, and varying across small lateral distances. A laminated Pliocene age sequence from Yallalie confirmed other studies that south‐western Australia was covered by a rich vegetation mosaic consisting of heath and wet rainforest elements. Proteaceae species were a consistent component of the counts, although diversity and abundance (maximum 5%) were low. A Holocene record from Two Mile Lake, near the Stirling Range, recorded little environmental change. Proteaceae species were noted in low abundance, at a maximum of 3.5% of the total pollen count. It is likely that both changing pollination mechanisms and changes in associated vegetation are important in determining the dispersal of Proteaceous pollen.  相似文献   
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