首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   258篇
  免费   14篇
  2024年   2篇
  2023年   5篇
  2022年   5篇
  2021年   10篇
  2020年   10篇
  2019年   10篇
  2018年   16篇
  2017年   16篇
  2016年   11篇
  2015年   8篇
  2014年   12篇
  2013年   43篇
  2012年   10篇
  2011年   11篇
  2010年   9篇
  2009年   13篇
  2008年   16篇
  2007年   9篇
  2006年   6篇
  2005年   10篇
  2004年   5篇
  2003年   5篇
  2002年   5篇
  2001年   5篇
  2000年   2篇
  1999年   1篇
  1998年   3篇
  1997年   1篇
  1995年   2篇
  1994年   1篇
  1993年   6篇
  1992年   2篇
  1985年   1篇
  1981年   1篇
排序方式: 共有272条查询结果,搜索用时 15 毫秒
1.
We analyze the response of municipalities to the occurrence of natural disasters in terms of spending behavior, use of upper-tier transfers and recovery, using balance sheet data of about 8,000 Italian municipalities for the period 2000–2015, and the universe of earthquakes events. We find evidence of increasing expenditure for about 12 years after the shocks, with asymmetric responses between earthquake-related and unconditional grants, and heterogeneous flypaper effects across the country. While in northern municipalities expenditure tends to regress to pre-earthquake levels, southern municipalities stick to higher expenditure levels when grants drop. This evidence is coupled with a faster recovery of private income and housing prices in northern municipalities.  相似文献   
2.
We have investigated the environmental history of human occupation and the development of agriculture in the eastern interior Lake District of Finland. The material consists of archaeological data, which is reviewed in topographical and agrogeological context, and pollen analytical evidence of agricultural indices from eight precisely dated (varved) lake sediment sequences. Before the Viking Age, archaeological evidence, consisting of stray finds, dwelling sites, and graves, is very scarce. Iron Age finds are clearly confined to the lowland environs with silty and clayey soils. During the Viking Age, the number of stray finds multiplies and the first cemeteries are established. Comparison between Viking and Crusade Period finds reveals a topographic shift toward higher locations and morainic soils. Most of the cup-stones are located on upland sites—that is, not in connection with known Iron Age sites. These are interpreted as medieval indicators of slash-and-burn farming of the fertile but stony supraaquatic morainic soils. There is pollen analytical evidence of sporadic cultivation in the area from the Bronze Age onward. Afterca. AD 700, the occurrence of cereal pollen grains becomes regular but remains discontinuous at each site until after the turn of the millennium. There is then an exponential rise in the cereal pollen rain, indicating a fully agricultural population.  相似文献   
3.
New industrial innovation policies like smart specialization aim at boosting economic growth by diversification towards more complex and higher value economic activities. This paper proposes a conceptual and analytical framework to support the design and implementation of such policies considering place-specific preconditions, particularly the differentiation of the regional system of innovation and entrepreneurship and the degree of current industrial diversification. The paper expands on the links between these preconditions and the barriers and opportunities for industrial diversification. Consequently, it proposes an archetypical place-based policy framework covering overall policy objectives as well as measures at the level of actors, networks, and the institutional and organizational support structures.  相似文献   
4.
ABSTRACT

This article argues that some of the contemporary attention given to sustaining habitation of regions and communities beyond capacity and prospects of economic growth can be understood by introducing the concept of ‘vicarious habitation’. By this term is understood ‘the notion of rural habitation performed by an active minority but on behalf of a much larger number, who (implicitly at least) not only understand, but, quite clearly, approve of what the minority is doing’. In many late modern societies, a substantial portion of the population seems willing to pay symbolically and politically to let a minority act on their behalf as caretakers of rural peripheries left behind by structural transformations. Signs of vicarious habitation occur that may vary in form and importance from country to country. Empirically, the argument is substantiated by Norwegian examples.  相似文献   
5.
Two sets of twelve Portland limestone tablets were attached to carousels outside and under the open, lightweight shelter at Bishop’s Palace (Witney, England) for 18 months to assess the influence of shelters on soiling and microbiological growth on stone. At the start, and at 6-month intervals, tablets were analysed using microscopy (optical and SEM), colour measurement (spectrophotometry), weight change measurement and salt content determination (ion chromatography). Concentrations of NO2 and SO2 were also monitored for a month using diffusion tubes. In addition, results were compared with those obtained by the UK National Materials Exposure Programme (NMEP) on chemical weathering rates. Differences in soiling and biological growth on sheltered and unsheltered samples, and their influence on limestone decay were established. The shelter is likely to reduce biological growth by modifying the micro-environmental conditions. However, it may also exacerbate dust deposition, which might increase decay rates in the long-term.  相似文献   
6.
Two important trends will strongly influence growth in emerging economies: one is the increasing role of services as drivers displacing manufacturing that has hitherto been the principal engine of growth in advanced and developing economies alike; the second is the parallel rise of trade in services both directly and embodied in products. The paper shows how the competitiveness and profitability of firms is becoming closely linked to the quality and innovativeness of services, and how the bundling of services with manufactures is the key to earning high returns over the longer term. Between 25 and 40 percent of value added in manufacturing is now in the form of services with high-end manufacturing becoming increasingly services-intensive. The future therefore, seems to lie in the cultivation of product-services systems that harness the full potential of manufacturing and associated pre- and post-production services such as design, R&D, marketing, and post-sale maintenance, especially of sophisticated equipment. The policy implications for emerging economies such as Russia, India, and China are manifold; e.g. for workforce skill development; for innovation systems (the nature of innovation and the orientation of R&D); for the contribution of capital to growth in a services-centered economy; for the maximizing of productivity gains from tradable and non-tradable services, which have been productivity laggards in the past; and for the creation of a facilitating institutional environment.  相似文献   
7.
This paper presents a review of services sector development in China. It is found that China’s services have recently emerged as the dominant contributor to economic growth and job creation. Trade in services has also increased dramatically, although China maintains a huge deficit. In comparison with economies at a similar stage of development, however, China’s services sector is lagging behind. Both GDP and employment shares of the services sector are relatively small. Services trade also accounts for a relatively small share of China’s total trade. In particular, China’s new services are underdeveloped. As per capita income rises and resultant urbanization accelerates, the country’s services sector is expected to expand further and hence play a key role in rebalancing China’s economy away from its over-reliance on manufacturing and exporting. To reach this goal, further reforms and prudent government policies are needed.  相似文献   
8.
The present study utilises dental histological methods to analyse enamel micro‐defects as indicators of early life stress in indigenous Muchik individuals interred at two sites: La Capilla Santa María Magdalena de Eten (CSMME) (n = 15) and La Capilla del Niño Serranito (CNS) (n = 15), both located in the Lambayeque Valley region of northern Peru. Individuals interred at CNS date to the Early Colonial Period (AD 1533–1610), and individuals interred at CSMME date to the Middle/Late Colonial Period (AD 1625–1760), thus permitting comparison of childhood stress events between the Early and Middle/Late Colonial Periods. Results reveal a high prevalence of Wilson bands at both sites, although a lower prevalence at the CSMME was observed in comparison with the CNS. This indicates that, over time, Muchik individuals in this town may have been able to acclimate to life under Spanish oppression. Stress chronologies suggest that early life stress possibly resulted from inadequate and less than desirable food and/or water available for supplemental feeding during early infancy, especially around the ages of 4 and 5 months. Furthermore, results show that individuals with enamel defects in the form of Wilson bands at both the CNS and CSMME had an earlier mean age‐at‐death (9.6 and 4.05 years, respectively) in comparison with those without observed Wilson bands (19.75 and 8.8 years, respectively). These results underscore the importance of not only regional and temporal studies of the biological consequences of Spanish contact in the Americas but also of investigating the relationship between early life stress and adult health and longevity in archaeological populations. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
9.
A range of archaeological and palaeoclimatic studies use isotopic analyses of ungulate hypsodont tooth enamel. Such studies commonly assume a constant growth rate, though this has not been fully tested. Here, we use stable isotope analyses of sequential enamel samples to study horse tooth growth. We fit the data using models corresponding to constant and exponentially decreasing rates of growth, and compare the results to metrical data showing the geometry and timing of apposition. The results indicate enamel apposition and maturation advances at an exponentially decreasing rate. An understanding of this variable growth rate is crucial for interpreting isotopic data from equid teeth.  相似文献   
10.
K. Samanian 《Archaeometry》2015,57(4):740-758
The technique of oil painting was introduced to Iran via a cultural exchange with Europe in the Safavid period (ad 1501–1736). Since the first attempt at scientific conservation of wall paintings in Iran in the 1960s, the nature of green pigment used in Persian wall paintings has not been clear, although work on contemporary miniature paintings has identified malachite and verdigris. PLM, FT–IR, SEM/EDX, GC–MS and the study of contemporary historical treatises of the Safavid period were the main tools used in the present study to identify the green pigments in Persian (oil‐based) wall paintings. Eight samples taken from the two famous Safavid buildings, Chehel Sotoon Palace and the Sukias House in Isfahan, were analysed. Here, the identification of copper‐based pigment and of verdigris in oil as oleate amends the existing knowledge of the green pigment used in these paintings. It also suggests that oleate was introduced to Persian artists via the European influence on Persian painting as a result of cultural exchange in the Safavid period, when the technique of Persian painting changed from tempera to oil painting. However, as verdigris in oil and resin can appear as oleate over time, it is unknown whether the Persian artists did this deliberately or accidentally.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号