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71.
The paper deals with the major chemistry and stable isotopes (hydrogen, oxygen, carbon, sulfur, strontium) of waters and solutes from the Salar de Atacama basin (Rio Pedro, Honar Creek and Laguna Chaxa) and Andean Altiplano (Laguna Miñique and Laguna Miscanti). The water inflows of the Salar are chemically quite different, the Rio San Pedro being of Na‐Cl type and the Honar Creek of Na‐HCO3 type, in keeping with the sedimentary‐evaporitic and volcanic nature of the catchment rocks respectively. The δ34S and δ18O values of sulfate and the 87Sr/86Sr ratio of strontium in the streams match those of drained rocks, whereas the δ13C values of dissolved carbonate are largely controlled by vegetation. The lagoons are evaporated meteoric water bodies, and the relative air humidity estimated from the slope of the isotopic evaporation line is in accordance with historical data on air humidity in the area. The Laguna Chaxa is Na‐Cl rich, and its isotopic composition are consistent with a mixed sedimentary‐volcanic provenance of sulfur and strontium solutes. The Laguna Miñique is Na‐SO4 rich, and its sulfate δ34S is nearly identical to that of Laguna Chaxa. The δ13C(HCO3) values are quite different in the Laguna Chaxa and Laguna Miñique, with the former being notably enriched in 13C probably because of preferential uptake of 12C by the high biological productivity occurring in the lagoon. The limited set of new data is interpreted in the context of a much larger literature database. In particular, previous chemical data on inflows and brines in the Salar de Atacama were revisited, and compared with evaporation path models and mineral stability diagrams (boron, lithium and Mg‐minerals) computed using updated software and thermodynamic databases. The modeling shows that the removal of boron and lithium from sulfate‐rich brines possibly occurs, respectively, as ulexite and sulfate salts, and carnallite should be the final magnesium phase of the brine evolution.  相似文献   
72.
Feasts provide a public forum where social statuses can be affirmed or challenged among pre-state societies. Documenting feasting behavior thus provides insight into the construction of prehistoric political power. This paper presents expected material patterns of feasting by focusing on intra-site variability in food preparation, presentation, and consumption. Expectations are evaluated by comparing ceramic, ground stone, obsidian, and faunal data recovered from Conchas phase (900–800 BCE) elite and village midden deposits at Cuauhtémoc in the Soconusco region of southern Mexico. I argue that elite feasting at Cuauhtémoc created political cohesion between elite and non-elite segments of society during the Conchas phase as a new polity emerged that was more socially stratified and politically hierarchical than anything previously known in the region.  相似文献   
73.
孙州霞 《攀登》2007,26(6):167-170
三江源地区的可持续发展,说到底是人的可持续发展,有了高素质的人,才会产生科学的、有远见卓识的人类活动。而教育的功能在于塑造人。因此,正确认识教育在三江源地区可持续发展中的重要功能与作用,其意义非同小可。  相似文献   
74.
This paper uses transaction‐based data to provide new insights into the link between the geographic proximity of businesses and associated economic activity. It develops two new measures of, and a set of stylized facts about, the distances between observed transactions between customers and vendors for a research intensive sector. Spending on research inputs is more likely with businesses physically closer to universities than those further away. Firms supplying a university project in one year are more likely to subsequently open an establishment near that university. Vendors who have supplied a project, are subsequently more likely to be a vendor on the same or related project.  相似文献   
75.
This research compares two current methods for recording bony changes at muscle attachment sites, called entheseal changes (EC); the Mariotti method and the Coimbra method, to evaluate the concordance and comparability of results in a post‐medieval skeletal collection from Aalst, Belgium (n = 116). For both methods, the EC scores produce broadly similar patterns, are symmetrical and differ between age groups. Statistical differences between the upper and lower limb and the lower limb of males and females only occur in the Mariotti method. With careful consideration of the influence of different EC score ranges, the results from the two methods can generally be compared.  相似文献   
76.
Stilt structures in the inter-tidal zone or over shallow water on fringing reefs are widely accepted as a feature of settlements of the Lapita cultural complex in Near Oceania. Claims for similar structures in a pre-Lapita context at the Apalo site in the Arawe Islands, New Britain, Papua New Guinea, have been queried on several grounds. Re-evaluation of the Apalo evidence, together with 10 additional AMS radiocarbon dates, establishes human activity associated with some form of structure and possibly with a ground stone axe about 400–500 years before the Lapita pottery occupation. The paucity of occupational refuse suggests a non-residential structure perhaps associated with water transport. Comparisons with the older Dongan midden site in the Sepik-Ramu basin suggest stilt structures were probably used there as well. An apparent shift in depositional processes between the pre-Lapita and Lapita use of Apalo could reflect changed sea conditions arising from increased ENSO activity.  相似文献   
77.
Glen Docherty has a long history of debris flow activity along the glen’s north east slope, but in early August 2015 a peaty-debris flow was triggered on the glen’s south west slope, involving an initial slide volume of 190?m3 debris/peat, of which 89?m3 consisted of peat. The flow merited study due to (a) its unusual location relative to debris flow activity affecting the rest of the glen, (b) the volume of peat involved and its effect on flow behaviour, (c) the role of immediate post-debris flow fluvial activity and (d) later responses to the event including subsequent weathering, fluvial activity and the potential for debris flow reactivation.  相似文献   
78.
Bioarchaeological research among prehistoric Pacific Coast populations has shown that external auditory exostoses (EAE) are found in high frequencies. On California's northern Channel Islands archaeological research has demonstrated that there was an intense exploitation of red abalone (Haliotis rufescens), particularly between ~8000 and 3500 years ago. If the Island Chumash were free‐diving for red abalone in subtidal waters, EAE should be prevalent in prehistoric populations from Santa Rosa Island. We recorded the presence or absence, number, side and severity of EAE growths for 207 adult individuals from three time periods on Santa Rosa Island. Our results show that ~11% of the total population was affected, including 22.5% of males and ~3.4% of females. The incidence among females increases from 0% in the Early period, to 2.6% in the Middle period, and 6.8% in the Late period. Overall these are lower rates than those reported for other Channel Island and Pacific Coast sites. Given the relatively low percentage of Santa Rosa Islanders affected with EAE, red abalones may have been harvested primarily in shallow waters rather than the deeper subtidal zone. Our data suggest that gender differences in food procurement activities existed on Santa Rosa Island throughout prehistory, congruent with the argument that EAE is an activity‐induced pathology that occurs with prolonged exposure to cold water and wind conditions. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
79.
对青海省重大文体活动进行市场化运作必要性的思考   总被引:1,自引:0,他引:1  
陈雪梅 《攀登》2005,24(4):66-68
文章通过对青海省近几年来重大文体活动运行现状的分析,指出了青海省重大文体活动现行机制中存在的主要问题。在此基础上提出为减轻政府财政压力和进一步提高大型活动的运作效率,必须建立健全市场化机制,通过市场化运作充分挖掘社会力量办重大文体活动的潜力,实现资金筹措多元化,保证青海省重大文体活动健康、持续的发展。  相似文献   
80.
本文依托会展研究、资源基础论和创业研究等理论研究成果,通过文献分析和理论推导,揭示会展经济效应的作用机制,提出了基于创业活动的会展产业经济效应作用过程概念模型。研究发现,会展产业的资源集聚和流动特性满足了创业活动的资源需求,使得新创企业克服新进入缺陷而提高存活率和绩效水平,即会展产业通过影响创业活动进而产生巨大经济效应。在这条具体的传导路径中,资源成为重要传导手段。  相似文献   
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