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91.
Application of the ALE technique for underwater explosion analysis of a submarine liquefied oxygen tank 总被引:1,自引:0,他引:1
The design of submarines has continually evolved to improve survivability. Explosions may induce local damage as well as global collapse to a submarine. Therefore, it is important to realistically estimate the possible damage conditions due to underwater explosions in the design stage. The present study applied the Arbitrary Lagrangian–Eulerian (ALE) technique, a fluid–structure interaction approach, to simulate an underwater explosion and investigate the survival capability of a damaged submarine liquefied oxygen tank. The Lagrangian–Eulerian coupling algorithm, the equations of state for explosives and seawater, and the simple calculation method for explosive loading were also reviewed. It is shown that underwater explosion analysis using the ALE technique can accurately evaluate structural damage after attack. This procedure could be applied quantitatively to real structural design. 相似文献
92.
The household economy of pastoralists and wage-labourers in the Richtersveld, South Africa 总被引:2,自引:1,他引:2
The Richtersveld is situated in an arid environment and its inhabitants are confronted with various hazards. Based on data collected during 22 months of ethnographic fieldwork, the livelihood strategies of Richtersvelders are explored. Besides a thorough examination of the diversified economy, the internal institutional arrangements for pooling and redistributing resources within households are analysed in this paper. Encouraging household members to engage in different activities and to share their income—as well as skills to manage the household budget properly—are integral to diversification and reducing the vulnerability of households. This study has shown that even in a community marked by considerable dependence on wage labour, almost three-quarters of the households are directly involved in stock farming. Although pastoralism still plays an important role for households, it has shifted from being the core economic activity to being an insurance against unemployment and contributing to subsistence. Stock farming serves to build up resilience through the diversification of economic activities inside the household. In the South African context, the relevance of activities dependent on land has implications not only for rural development, but also for post-apartheid land and agrarian reform. 相似文献
93.
We review the definitions, population trends, and characteristics of megacities. Characteristics of megacities are, apart
from their size, their complexity in terms of administration, infrastructure, traffic, etc., and at the same time the speed
of change. Vulnerabilities and risk potential are discussed using the examples of Mexico City and Mumbai. We present the experience
accumulated in the 6 years work of the Earthquakes and Megacities Initiative (EMI, ) with more than 20 large cities around the world, mostly located in the developing world. On this background we analyze obstacles
that keep megacities from developing an efficient approach towards disaster mitigation and define a strategy that might overcome
these problems. The key element of this strategy is the development of a Disaster Risk Management Master Plan (DRMMP) for
cities. Currently the Istanbul Earthquake Master Plan (IEMP) serves as best example for an appropriate strategy for disaster
reduction in megacities. 相似文献
94.
Mountain regions are subject to a variety of hazardous processes. Earthquakes, landslides, snow avalanches, floods, debris
flows, epidemics and fires, among other processes, have caused injury, death, damage and destruction. They also face challenges
from increased populations, and expansion and intensification of␣activities, land uses and infrastructure. The combination
of a dynamic bio- geophysical environment and intensified human use has increased the vulnerability of mountain social–ecological
systems to risk from hazards. The ability of social–ecological systems to build resilience in the context of hazards is an
important factor in their long-term sustainability. The role of resilience building in understanding the impact of hazards
in mountain areas is examined and illustrated, in part, through examples from Canada and India. Resilient social–ecological
systems have the ability to learn and adjust, use all forms of knowledge, to self-organize and to develop positive institutional
linkages with other social–ecological systems in the face of hazards. The analysis suggests that traditional social–ecological
systems built resilience through avoidance, which was effective for localized hazards. The more recent development and implementation
of cross-scale institutional linkages is shown to be a particularly effective means of resilience building in mountain social–ecological
systems in the face of all hazards. 相似文献
95.
Small island developing states (or SIDS) are exposed to a large number of natural hazards and many characteristics of small
island developing states make them particularly vulnerable to the impacts of natural hazards. In spite of this acknowledged vulnerability, there are relatively few studies which focus
on the impacts of natural hazards in these countries. This paper presents a review of our current state of knowledge of impacts
in small island developing states and highlights a number of research needs. Central to these is the need to integrate natural
hazards research within a sustainable development context and the need to exploit existing procedures such as government coordinated
disaster impact assessments to generate a detailed understanding of natural hazards impacts. 相似文献
96.
Standardization of vulnerability maps 总被引:3,自引:0,他引:3
Groundwater vulnerability assessment schemes are used for the estimation of potential groundwater contamination at different
scales and on different administrative levels. However, the term vulnerability is not standardized and the available methods
are not able to give a unique assessment of vulnerability creating thus uncertainty in the interpretation and in further application
concerning decision creation processes. To judge the information of vulnerability maps certainly and to value the general
trends of vulnerability assessment of different methods, four different vulnerability methods of the parametric system group
have been applied on a karst area in southwestern Germany to perform a comparative assessment and correlation of these vulnerability
assessment methods, namely DRASTIC, PI, EPIK, and GLA. It is shown that by means of simple statistical considerations the
first highly different vulnerability maps could be made more coherent after reclassification. The reclassified vulnerability
assessments show a more consistent vulnerability distribution pattern and provide the possibility of area-wide validation
of the maps as the chosen vulnerability classification is theoretically connected to the mean transit time of percolation
water and is largely independent of the applied vulnerability assessment method. 相似文献
97.
How might geographers respond ‘generously’ to a disaster on the scale of the Indian Ocean tsunami? Critical geographers and other left intellectuals have chosen to stress the way pre-existing social forces conditioned human vulnerability, and have implied that ordinary people ‘here’ were implicated in the suffering of others ‘there’ through their positioning in chains of causality. Critics have also sought to expose the bias, unjustness and inappropriateness of post-tsunami patterns of donation and programs of aid and recovery. A supplement to this mode of critique is offered in the form of a view of disasters and human vulnerability that hinges on the idea of the self as ‘radically passive’: that is, as inherently receptive to both the stimuli that cause suffering, and to the demands of others who are suffering. All forms of thought – including geography and disaster studies should themselves be seen as ‘vulnerable’ and responsive to the impact to disasters. The idea that every ‘self’ bears the trace of past disasters – and past gifts of others – forms the basis of a vision of bodies and communities as always already ‘fractured’ by disaster – in ways which resist being ‘brought to light’. This offers a way of integrating human and physical geographies through a shared acknowledgement of what is unknowable and absent. It is also suggestive that gratitude might be an appropriate response to a sense of indebtedness to others – for who we are, as much as for what we have done. 相似文献
98.
Estimating the confidence of earthquake damage scenarios: examples from a logic tree approach 总被引:1,自引:0,他引:1
Earthquake loss estimation is now becoming an important tool in mitigation planning, where the loss modeling usually is based
on a parameterized mathematical representation of the damage problem. In parallel with the development and improvement of
such models, the question of sensitivity to parameters that carry uncertainties becomes increasingly important. We have to
this end applied the capacity spectrum method (CSM) as described in FEMA HAZUS-MH. Multi-hazard Loss Estimation Methodology, Earthquake Model, Advanced Engineering Building Module. Federal Emergency Management Agency, United States (2003), and investigated the effects of selected parameters. The results demonstrate that loss scenarios may easily vary by as
much as a factor of two because of simple parameter variations. Of particular importance for the uncertainty is the construction quality of the structure. These results represent a warning against simple acceptance of unbounded damage scenarios and strongly
support the development of computational methods in which parameter uncertainties are propagated through the computations
to facilitate confidence bounds for the damage scenarios. 相似文献
99.
An earthquake scenario for the microzonation of Sofia and the vulnerability of structures designed by use of the Eurocodes 总被引:3,自引:0,他引:3
Paskaleva Ivanka Dimova Silvia G.F. Panza Giuliano Vaccari Franco 《Soil Dynamics and Earthquake Engineering》2007,27(11):1028-1041
The study of the site effects and the microzonation of a part of the metropolitan Sofia, based on the modelling of seismic ground motion along three cross-sections are performed. Realistic synthetic strong motion waveforms are computed for scenario earthquakes (M=7) applying a hybrid modelling method, based on the modal summation technique and finite differences scheme. The synthesized ground motion time histories are source and site specific. The site amplification is determined in terms of response spectra ratio (RSR). A suite of time histories and quantities of earthquake engineering interest are provided. The results of this study constitute a “database” that describes the ground shaking of the urban area. A case study of experiment-based assessment of vulnerability of a cast-in-situ single storey, industrial, reinforced concrete frame, designed according to Eurocodes 2 and 8 is presented. The main characteristics of damage index and storey drift are discussed for the purposes of microzonation. 相似文献
100.