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81.
B. Warner 《Planetary and Space Science》1961,5(4):283-284
The hypothesis proposed by Gold that the lunar maria are composed of dust is shown to give a detailed explanation of the present appearance of the maria. It is also shown that many bright rays may not have the extent and intensity as they had when they were formed. 相似文献
82.
Zhenbo Liu Xuezheng Shi Eric Warner Yunjian Ge Dongsheng Yu Shaoxiang Ni Hongjie Wang 《International Journal of Applied Earth Observation and Geoinformation》2008
Locust plagues have been the source of some of the most severe natural disasters in human history. Soil moisture content is among the most important of the numerous factors influencing plague onset and severity. This paper describes a study initiated in three pilot locust plague monitoring regions, i.e., Huangzao, Yangguanzhuang, and Tengnan in Huanghua county, Hebei province, China, to examine the impact of soil moisture status on oriental migratory locust [Locusta migratoria manilensis (L.) Meyen] plague breakout as related to the life cycle, oviposition in autumn, survival in winter, and incubation in summer. Thirty-nine temperature vegetation dryness index (TVDI) data sets, which represent soil moisture content, were extracted from MODIS remote sensing images for two representative time periods: a severe locust plague breakout year (2001–2002) and a slight plague year (2003–2004). TVDI values demonstrated distinctive soil moisture status differences between the 2 years concerned. Soil moisture conditions in the severe plague year were shown to be lower than those in slight plague year. In all three pilot regions, average TVDI value in the severe plague year was 0.07 higher than that in slight plague year, and monthly TVDI values in locust oviposition period (September and October) and incubation period (March, April and May) were higher than their corresponding monthly figures in slight plague year. No remarkable TVDI differences were found in other months during the locust life cycle between the 2 years. TVDI values for September and October (2001), March, April and May (2002) were 0.11, 0.08, 0.16, 0.11 and 0.16 higher than their corresponding monthly figures in 2003–2004 period, respectively. 相似文献
83.
Ryan J. Bunting Oliver Yang Chang Christopher Cowen Richard Hankins Staci Langston Alexander Warner 《The Professional geographer》2018,70(1):34-46
The combination of crime mapping and geospatial analysis methods has enabled law enforcement agencies to develop more proactive methods of targeting crime-prone neighborhoods based on spatial patterns, such as hot spots and spatial proximity to specific points of interest. In this article, we investigate the spatial and temporal patterns of the neighborhood crimes of aggravated assault and larceny in 297 census tracts in Miami–Dade County from 2007 to 2015. We use emerging hot spot analysis (EHSA) to identify the spatial patterns of emerging, persistent, continuous, and sporadic hot spots. In addition, we use geographically weighted regression to analyze the spatial clustering effects of sociodemographic variables, poverty rate, median age, and ethnic diversity. The hot spots for larceny are much more diffused than those for aggravated assaults, which exhibit clustering in the north over Liberty City and Miami Gardens and in the south near Homestead, and the ethnic heterogeneity index has a moderate and positive effect on the incidence of both larceny and aggravated assaults. The findings suggest that law enforcement can better target prevention programs for violent versus property crime using geospatial analyses. Additionally, the ethnic concentration of neighborhoods influences crime differently in neighborhoods of different socioeconomic status, and future studies should account for spatial patterns when estimating conventional regression models. 相似文献
84.
85.
Robin Frederick Warner 《Central European Journal of Geosciences》2012,4(3):357-375
This study of Durance River terrace morphologies in the lower 200 km of the valley shows that terrace ages, elevations and heights above the river generally all increase upstream. It is based on extensive fieldwork checked against geological maps and memoirs. Subdivision of the valley, based on gorges and former tectonic blockages, is relevant because there are no Durance terraces downstream of Mallemort and there are considerable differences between each reach. For most of the Pleistocene, the river was diverted through the Crau Plains to the sea. Below the Mirabeau gorge, there are a few narrow low and middle terraces. The best terrace development is between Mirabeau and the Sisteron defile. Upstream of that barrier there is glacial dominance. Changes in terrace continuity are illustrated by means of height-range diagrams and their rates of dissection have been quantified approximately, based on cosmic ray exposure age modelling. Climate forcing cannot explain all the changes found. The influence of tectonic activity was found to increase in an upstream direction and also with age on the southwestern flanks of the Alps. 相似文献
86.
Climate change,environmental degradation and migration 总被引:1,自引:0,他引:1
Climate change will have a progressively increasing impact on environmental degradation and environmentally dependent socio-economic
systems with potential to cause substantial population displacement. The key concerns in Less Developed Countries (LDCs) will
include serious threats to food security and health, considerable economic decline, inundation of coastal areas, and degradation
of land and fresh water resources (Reuveny in Polit Geogr, 2007). The relationship between environmental change and potential humanitarian crises has been captured by: McGregor (Geography
and refugees: patterns and processes of change, Belhaven Press, London, pp 159–70, 1993), Kibreab (Environment and Population Change, International Union for the Scientific Study of Population, Liège, 1994), Kibreab (Disasters 21(1):20–38, 1997), Myers (Bioscience 43:752–761, 1993), Myers and Kent (Environmental exodus: an emergent crisis in the global arena, Climate Institute, Washington, DC, 1995), Black (New Issues in Refugee Research, Working Paper no. 34, 2001), Lee (Environmental matters: conflict, refugees and international relations, World Human Development Institute Press, Seoul
and Tokyo, 2001), Castles (Environmental Change and Induced Migration: Making Sense of the Debate Working Paper No. 70, 2002), Christian Aid (Human tide: the real migration crisis, Christian Aid, London, 2007), and Massey et al. (, 2007). However, we know little about the interplay between environmental change and stresses on ecological systems, resulting
socio-economic vulnerability and potential outcomes in terms of population displacement or induced migration. So far these
relationships are poorly conceptualized, lack systematic investigation, and are reduced to simplistic causal explanations.
This leads to misleading conclusions that deny the complex multivariate processes—environmental, political, social, and economic—
which are the root causes of environmentally induced migration and/or conflict. When people are faced with severe environmental
degradation they have one of three options: (1) stay and adapt to mitigate the effects; (2) stay, do nothing and accept a
lower quality of life; or (3) leave the affected area. The process of movement and migration is usually subject to a complex
set of push and pull forces, where push forces relate to the source area while pull factors relate to the destination. These
forces are in constant flux, as much as environmental change, and interact with socio-economic and political conditions including
state or government decision making powers, which can tip the balance at any point by either denying movement or the right
to settle elsewhere. The paper focuses on how environmental change and environmental hazards contribute to the migration by
exploring the mechanisms through which vulnerability and migration are linked—via livelihoods, relocation policies, and other
factors. The paper begins by outlining important definitions of what is environmentally induced migration. The paper also
considers the question of whether migration is a process that reduces or increases vulnerability. The paper draws on multidisciplinary
literature including ecology, environment, and climate change; sociology of migration; anthropology of displacement; and economics;
but also on preliminary from various case studies in Egypt, Vietnam, and Mozambique. 相似文献
87.
88.
N. Mhlahlo D. A. H. Buckley V. S. Dhillon S. B. Potter B. Warner P. Woudt G. Bolt J. McCormick R. Rea Denis J. Sullivan F. Velhuis 《Monthly notices of the Royal Astronomical Society》2007,380(1):133-141
We report on the detection of an ∼5900 s quasi-periodic variation in the extensive photometry of TX Col spanning 12 yr. We discuss five different models to explain this period. We favour a mechanism where the quasi-periodic variation results from the beating of the Keplerian frequency of the 'blobs' orbiting in the outer accretion disc with the spin frequency and from modulated accretion of these 'blobs' taking place in a shocked region near the disc/magnetosphere boundary. 相似文献
89.
Timothy J. Taylor Carmen T. Agouridis Richard C. Warner Christopher D. Barton Patrick N. Angel 《水文研究》2009,23(23):3372-3381
Heavily compacted lands, typical of traditional surface mine reclamation techniques, have been shown to hinder tree growth, increase levels of flooding, and produce suboptimal water quality. Utilizing loose‐dumped spoil, in accordance with the Forestry Reclamation Approach (FRA), has demonstrated success with regards to promoting tree growth and survival; however, additional information is needed to assess the potential of FRA to ameliorate other environmental concerns related to water quantity. To better understand the hydrologic characteristics of loose‐dumped spoil, key hydrograph parameters (discharge volume, peak discharge, discharge duration, lag time, and response time) were monitored for three common spoil types: (1) predominately brown weathered sandstone, (2) predominately gray weathered sandstone, and (3) a mixture of both sandstones and shale. Although spoil types were found to differ hydrologically, these differences were relatively minor. Measured discharge volumes were low (averaging 12% of rainfall for all events and treatments), peak discharge rates were small (between 2·5 × 10?5 and 3 × 10?3 m3/s), and the duration of discharge was long (6 days on average). From a hydrologic perspective, the results of this study indicate that mine spoils need not be segregated for reclamation as long as the spoil is placed in accordance with the loose‐dumped techniques as outlined in the FRA. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
90.