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101.
ABSTRACT

Mainstream ecological thought is explored in three sections: (i) Epistemological traits. Given the typical scientific development and the necessity of preserving our intellectual heritage, the conservatism outlined in (i) is cyclical, so its stages are graphically summarized. (ii) Methodological benchmarks antithetically derived from (i), in order to get faster advancement consistent with the growing environmental challenges which spur ecological development. (iii) The renaissance of an old paradigm. This section exposes the misunderstanding of the physical concept of equilibrium by the mainstream ecological thought; this explains its current state. Consequently, section (iii) also summarizes the evolution of a recent set of proposals (organic biophysics of ecosystems) that rescues the foundational paradigm of ecosystem ecology based on physics, neglected by the mainstream thought before producing its most valuable results. We highlight that the main problems emerge from the weakness of integration between ecology, physics and epistemology, and spurious links between ecology and neoclassical economics.  相似文献   
102.
段娟 《当代中国史研究》2012,(6):100-109,128
三线建设是中国在中西部地区进行的一场以备战为指导思想,以交通、国防科技和基础工业为主体的大规模的基本经济建设。近20年来,关于三线建设决策的形成、实施、评价以及与当前西部大开发的关系等相关问题的研究,一直是学术界关注的热点,无论在文献资料的公布方面,还是在相关问题的研究方面,都取得了很大进展。通过梳理近20年来的研究成果,可看出目前的研究仍存在一些薄弱环节,需要学者们继续挖掘档案资料、拓宽研究视野、丰富研究方法,并开展国内外学术交流,以促进研究的进一步深入。  相似文献   
103.
Of the parasite eggs discovered in ancient samples from Korean archaeological sites, Paragonimus spp. are of particular importance in that they are regarded as one of the most insidious trematode infection sources. Although their infection prevalence decreased rapidly in the early 20th century, archaeoparasitological studies on the species are still required, as historical knowledge of paragonimiasis remains far from comprehensive. Fortunately, we recently were given a chance to examine a medieval Korean mummy in a good state of preservation. Using morphological techniques, we discovered evidence of ectopic paragonimiasis in the sample from the 17th-century female. When the ITS 2 gene was extracted, amplified and sequenced from Paragonimus eggs, it showed 100% homology to the sequences of modern Paragonimus westermani reported from Korea and Japan, forming a cluster distinct from South Asian P. westermani. Our report is the first-ever analysis of ancient Paragonimus DNA from any archaeological field in the world. The ectopic paragonimiasis diagnosis made in this study, especially involving the liver sample, also is the first of its kind in archaeoparasitology.  相似文献   
104.
ABSTRACT In this paper, we introduce a new spatially constrained clustering problem called the max‐p ‐regions problem. It involves the clustering of a set of geographic areas into the maximum number of homogeneous regions such that the value of a spatially extensive regional attribute is above a predefined threshold value. We formulate the max‐p ‐regions problem as a mixed integer programming (MIP) problem, and propose a heuristic solution.  相似文献   
105.
Regional policies seek to enable regions to increase their competitiveness and development, and as such one priority Objective of activities financed by Structural Funds is higher employment, higher productivity and economic activity. How efficiently the regions apply the funds is a fundamental issue for the development and continuity of regional policies. We therefore consider that determining the efficiency of European regional policies is an issue of high importance, and this is the main aim of this study. We have considered it appropriate to use the available information to apply a mathematical technique known as Data Envelopment Analysis (DEA), which allows us to calculate the technical efficiency and inefficiency of the Structural Funds applied in the Objective 1 regions for the period 2000–2006. Furthermore, we wish to determine if the regions have been more efficient in creasing their levels of employment or in increasing productivity. Our study applies this methodology along with other methods like regression analysis, profit analysis and factorial analysis to determine the variation in the rate of unemployment and productivity in these European Regions. The study reveals that only eight regions are efficient, although none of them is run in all the models.  相似文献   
106.
107.
The objective in current design practice for parking structures is that energy is dissipated through the formation of plastic hinges at the base of shear walls while floor diaphragms remain elastic and are vertically supported by a combination of shear walls and gravity resisting columns. Unfortunately, this objective is not always achieved due to inaccuracies in current methods for calculating demands on shear walls and in calculating the capacity of shear walls (IBC 2003 International Building Code. International Conference of Building Officials. Whittier, CA.  [Google Scholar], ACI code). When demands are overestimated and capacity underestimated, then diaphragm can fail prior to flexural yield of shear walls as was observed in several parking structures in the 1994 Northridge earthquake.

Eigenvalue and inelastic dynamic response analyses were performed in order to investigate the effects of diaphragm flexibility on wall responses and of wall overstrength on diaphragm responses. The elongated periods of parking structures due to diaphragm flexibility were found to significantly decrease seismic force demand on shear walls relative to what is calculated using codes of practice in which diaphragms are assumed to be rigid. This leads to the over design of shear walls, which further compounds the problem by preventing the flexural yielding of these walls and thereby driving inelastic response to diaphragms. Various degrees of diaphragm flexibility, shear wall layout, seismic zone, and the number of stories were considered in these analyses.

Inelastic static pushover analyses were preformed to investigate the design and capacity evaluation of shear walls. The results illustrate that the shear capacity of walls may be close to twice that calculated by codes of practice. The largest overstrengths were observed in shear walls with low height-to-length ratios in which a significant portion of the lateral load was taken by direct strut action to the foundation and without placing demands on the longitudinal tension reinforcement in the shear walls. The article concludes that methods in codes of practice for calculating shear wall demands and capacities need to be improved if good seismic performance of parking structures is to be achieved.  相似文献   
108.
The authors propose a scheme of economic regionalization for Cuba, based on Soviet Marxist principles. These include the idea of objective existence of a region, independently of man's will; the need for considering future developmental prospects; energy supply; the prerequisites for integrated development of the regional economy; the presence of a regional specialization; maximum promotion of a geographical division of labor, and the factor of the country's defense capability. The resulting system of six regions in described.  相似文献   
109.
Late Bronze Age Handmade Burnished Ware (HMBW) from Tell Kazel was studied by thin-section petrography and neutron activation analysis in order to investigate its manufacturing technology and origin of production. Results show that the majority of the HMBW fabric groups point to a local area of production while a few petrographic loners might have been produced elsewhere in the Akkar Plain or imported. The manufacturing technique, in terms of clay paste recipe, forming and finishing techniques, is however new in the Tell Kazel pottery assemblage, hinting at the work of foreigners present at the site. The historical and archaeological contexts further suggest that these foreigners were some of the Sea Peoples and the stylistic and analytical data further reinforce the link between the northern Levant and the western Mediterranean.  相似文献   
110.
Many Pleistocene caves and rock shelters contain evidence of carnivore and human activities. For this reason, it is common to recover at these sites faunal remains left by both biological agents. In order to explain the role that carnivores play at the archaeological sites it is necessary to analyse several elements, such as the taxonomical and skeletal representation, the age profiles, the ratio of NISP to MNI, the anthropogenic processing marks on the carcasses (location and purpose of cutmarks and burning and bone breakage patterns), carnivore damage (digested bones, location and frequencies of toothmarks and bone breakage), length of the long bones, frequencies of coprolites and vertical distribution of the faunal remains, inter alia. From this, the documentation of carnivores in a faunal assemblage with a clear anthropogenic component can be understood from three main phenomena: (1) the carnivores as accumulators and the use of the site as a den; (2) carnivores as scavengers of hominid refuse and; (3) carnivores as hominids’ prey. Of these three phenomena, the last one is the least documented at the Middle Pleistocene sites. From this perspective, here we present the case of the anthropogenic use of a lion (Panthera leo fossilis) from level TD10-1 of Gran Dolina (MIS 9, Sierra de Atapuerca, Burgos, Spain). The lion bone remains show signs of direct interaction between this big cat and human groups that occupied Gran Dolina in these chronologies. From this perspective, the aim of this paper is to contribute to the knowledge of the role developed by large carnivores in the anthropogenic contexts and to provide data on human use of these predators at the European Middle Pleistocene sites.  相似文献   
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