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11.
We compared independent mobility (freedom to move around the neighbourhood – or similar – without adult accompaniment) among English and Australian schoolchildren. Parents reported mobility licences granted to their children (e.g. allowing them to cross main roads alone) and accompaniment on local trips. Children reported travel mode to school. We examined associations between mobility licences and independent school journeys, and accompaniment on local trips. Among 10–12-year-olds, English children had more licences than Australian children. Mobility licences were directly associated with independent school journeys among primary but not among secondary schoolchildren who travelled further; and inversely associated with parental accompaniment to other destinations. Influences on parental restrictions should be examined to promote children's independent mobility.  相似文献   
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The thermal histories of archaeological cereal grains have been explored with electron spin resonance spectroscopy by a quantitative study of pyrolysis-induced radical carbon. Comparison with modern samples of heated cereal grain has shown that the g value of the radical carbon signal is characteristic of exposure to a previous maximum temperature, and studies of other signal parameters suggest that further information, such as the duration of previous heating, may be deduced from such studies. The proposed method offers the possibility of quantitatively rigorous measurement in archaeological studies of cultural and technological processes that previously relied upon subjective assessment.  相似文献   
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Dealing with differing and sometimes conflicting criteria for priority‐setting is an essential part of sustainable natural resource management. However, all too often, these ethical and political considerations are neglected within a planning regime based upon apparently ‘objective’ biophysical assessment techniques. Input into associated decision‐making processes is also frequently restricted to a narrow range of ‘stakes’ based upon historical and geographic circumstances. This paper reports on the findings of interviews and discussion groups in the Hunter Valley, New South Wales, which aimed to canvass the diversity of perceptions of distributive and procedural justice in river rehabilitation. A range of biophysical and social criteria for setting priorities in rehabilitation work was identified. Participants also had differing ideas on the composition of decision‐making bodies and on decision‐making processes. The key implications of these findings are that sustainable river management policy needs to openly address differing conceptions of justice and that rehabilitation practice should be holistic, transdisciplinary and concerned with both outcome and process.  相似文献   
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Man's (or, more probably, Woman's) first cereal crops were sown from seed gathered from wild stands, and it was in the course of cultivation that domestication occurred. Experiments in the measurement of domestication rates indicate that in wild-type crops of einkorn, emmer, and barley under primitive systems of husbandry: (a) domestication will occur only if they are harvested when partially or nearly ripe, using specific harvesting methods; (b) exposure to shifting cultivation may sometimes have been required; and (c) under these conditions, the crops could become completely domesticated within 200 years, and perhaps only 20–30 years, without any conscious selection. This paper (a) considers possible delays in the start of domestication due to early crops of wild-type cereals lacking domestic-types mutants; (b) examines the husbandry practices necessary for these mutants to enjoy any selective advantage; (c) considers the state of ripeness at harvest necessary for the crops to respond to these selective pressures; (d) outlines field measurements of the selective intensities arising from analogous husbandry practices applied experimentally to living wild-type crops; (e) summarizes a mathematical model which incorporates the measured selective intensities and other key variables and which describes the rate of increase in domestic-type mutants in early populations of wild-type cereals under specific combinations of primitive husbandry practices; (f) considers why very early cultivators should have used those husbandry methods which, we suggest, led unconsciously to the domestication of wild wheats and barley; and (g) considers whether these events are likely to leave archaeologically recognizable traces.  相似文献   
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Despite its analytic deficiencies and the doctrinaire purposes it has been made to serve, the rational choice approach to political analysis can have considerable explanatory value. Three examples are given of the utility of the sub-field of rent-seeking analysis in illuminating how public resources for agricultural development are allocated in developing countries: rural-urban relations, resource allocation among agricultural services, and irrigation policy.  相似文献   
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The Akko 1 shipwreck was discovered inside the harbour of the old walled city of Akko (Acre, St. Jean d'Acre, Akka), Israel. The ship's hull was built mainly of oak, with closely-set framing timbers that created a solid side. The shipwreck was apparently a result of the naval bombardment of the town in 1840.  相似文献   
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