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991.
Increasing penetration by the market into the governing of agri-environments, and the use of market-oriented approaches in an attempt to produce more sustainable outcomes, is a characteristic feature of what scholars have called the ‘neoliberalisation of nature’. While accepting that neoliberal forms of governing tend to extend market relations into new domains, a number of scholars have argued that they may at the same time create spaces of resistance, open up progressive political possibilities, or incorporate alternative rationalities of governing. This literature has so far focused primarily on the policy and/or programme level with limited connection made to the growing body of research that explores landholder responses to specific market instruments. We address this gap by focusing on a market instrument – Wimmera Habitat Tender – in the State of Victoria, Australia, which aims to provide incentives for farmers in managing native vegetation. This case study explores how a specific tender-based market instrument seeks to construct natural resource managers as neoliberal subjects, as well as the complex ways in which farmers contest or resist the neoliberal governing of their agri-environmental practices. Through our analysis we contend that closer scrutiny of how the techniques underpinning market-based environmental instruments are taken up or resisted contributes to a more robust understanding of the environmental possibilities created by market instruments, as well as the challenges involved in attempts to neoliberalise nature. 相似文献
992.
东南极拉斯曼丘陵泥质麻粒岩变质作用演化 总被引:5,自引:0,他引:5
普里兹湾拉斯曼丘陵代表了东南极一条重要的早古生代的~530Ma泛非期(Pan-African)高级构造活动带。然而,该区早期的晚元古代的~1000Ma格林维尔期(Grenvellian)高级变质作用的演化历史至今仍有争论。该区呈透镜状产出的泥质麻粒岩峰期矿物组合(M1)为石榴石+堇青石+斜方辉石+钾长石+石英,峰期石榴石变斑晶发育堇青石或堇青石+斜方辉石反应边(M2)。利用Thermocalc程序在KFMASH模式体系对该泥质麻粒岩进行的定量模拟表明,其峰期矿物组合是由反应石榴石+黑云母+石英=堇青石+斜方辉石+钾长石+熔体形成的。利用Themocalc平均P-T计算方法获得峰期M1变质P-T条件为~0.9GPa和~900℃,而叠加的M2组合反映了一个减压冷却的过程,其变质P-T条件为~0.7GPa和800~850℃。结合已有的年代学数据,认为该区泥质麻粒岩的峰期M1矿物组合反映晚元古代(~1000Ma)格林维尔期挤压D1构造事件,而叠加的M2矿物组合与M3蠕虫状结构则形成于早古生代泛非期(~530Ma)D2~D3高级扭压剪切构造期间。该扭压事件导致了面状高低应变带的发育以及进步花岗岩和伟晶岩的侵入。 相似文献
993.
Chris Yakymchuk Lyal B. Harris Laurent Godin 《International Journal of Earth Sciences》2012,101(2):463-482
Centrifuge analogue modelling illustrates the progressive development of active folds in multilayers upon a ductile substrate
during layer-parallel shortening. Models simulate folding of a mechanically stratified sedimentary sequence upon migmatitic
gneisses in a large hot orogen, or upon a thick basal evaporite ± shale sequence in deeper levels of fold belts. The absence
of a weak low-viscosity and low-density layer at the interface promotes infolding of the cover sequence and ductile substrate,
whereas a planar upper surface to the basal ductile substrate is preserved when it is present. Whilst fold style, wavelength,
and deformation of the interface with the ductile substrate differ depending on whether a low-viscosity and low-density layer
is present at the base of the cover sequence, there is no marked systematic curvature of fold axes as seen in previous sandbox
models for fault-bend or fault propagation folding during bulk shortening. Bulk shortening of a layered sequence with relatively
thick individual layers above a ductile substrate promotes a regular and upright train of buckle folds, whereas thinner layers
promote a more irregular distribution of buckle folds with variable vergence, style, and amplitude. Buckle folds above a ductile
substrate progressively develop during bulk shortening from open and upright, to angular and tight, and may further develop
into cuspate structures above relatively weak horizons. Relatively thick weak horizons within the layered sequence during
bulk shortening interrupt regular fold patterns up structural section and allow out-of-phase folds to develop above and below
the weak horizon. 相似文献
994.
We developed a food web model of central Puget Sound to provide science-based support for ecosystem-based management and to
refine our understanding of bottom-up and top-down trophic forcing. Phytoplankton accounted for a large fraction of total
biomass, total throughput, and caused considerable bottom-up effects in most functional groups in a dynamic simulation fit
to time series data from 1981 to 2000. Top-down control was most apparent in the case of bald eagles (Haliaeetus leucocephalus), which exhibited keystone tendencies and appeared capable of causing trophic cascades. Increasing top-down control in several
predator–prey relationships improved model fits to time series data from 1981 to 2000, but not as much as introducing non-equilibrium
dynamics (biomass accumulation terms) to several key vertebrates. Fishing had little effect on system dynamics. Our model
appears well-suited for addressing strategic, scenario-based questions of how the community as a whole will respond to management
actions. 相似文献
995.
Chris Lutes Chase Holton Brian Schumacher John Zimmerman Andrew Kondash Robert Truesdale MS AB. 《Ground Water Monitoring & Remediation》2021,41(2):99-111
Temporal and spatial variability of indoor air volatile organic compound (VOC) concentrations can complicate vapor intrusion (VI) assessment and decision-making. Indicators and tracers (I&T) of VI, such as differential temperature, differential pressure, and indoor radon concentration, are low-cost lines of evidence to support sampling scheduling and interpretation of indoor air VOC sampling results. This study compares peak indoor air chlorinated VOC concentrations and I&T conditions before and during those peak events at five VI sites. The sites differ geographically and in their VI conceptual site models (CSM). Relative to site-specific baseline values, the results show that cold or falling outdoor temperatures, rising cross slab differential pressures, and increasing indoor radon concentrations can predict peak VOC concentrations. However, cold outdoor air temperature was not useful at one site where elevated shallow soil temperature was a better predictor. Correlations of peak VOC concentrations to elevated or rising barometric pressure and low wind speed were also observed with some exceptions. This study shows how the independent variables that control or predict peak indoor air VOC concentrations are specific to building types, climates, and VI CSMs. More I&T measurements at VI sites are needed to identify scenario-specific baseline and peak related I&T conditions to improve decision-making. 相似文献
996.
Seismic sentinel? An analysis of captive giant panda behavior in response to the Lushan earthquake in China 下载免费PDF全文
Yuan Jin Xiaozan Ma Bo Luo Guiquan Zhang Rongping Wei Desheng Li Hemin Zhang Chris Newman Christina Buesching Dingzhen Liu 《地震科学(英文版)》2021,34(6):522-530
It is widely believed that various animal species can sense and respond to the geophysical stimuli that precede earthquakes, especially electromagnetic fields, although supporting field evidence is mostly anecdotal. Here we report on the reactions of four female giant pandas under observation over the three days prior to the Lushan (30.1°N, 103.0°E) magnitude 7.0 earthquake that occurred in Sichuan province, China, on April 20, 2013. We observed no significant generalized behavioral anomalies indicative of them perceiving an impending earthquake. We also observed no startle behaviors in the 5 s prior to tremors commencing, indicating that these pandas either did not detect or did not respond to precursor P-waves. Our findings suggest that although giant pandas have evolved in, and continue to occupy exclusively, a seismically active range in central China, they do not appear to perceive pre-earthquake geophysical warning signs. 相似文献
997.
Yardangs are streamlined ridges that form in arid environments on Earth and Mars through wind-driven abrasion of consolidated substrates. Currently, there is limited consensus on the mechanisms that initiate and establish patterns of yardangs on the landscape. In this work, we examine the spatial organization of yardangs in the Campo de Piedra Pómez ignimbrite deposit of north-western Argentina and identify evidence of antecedent controls on yardang patterns and formation. We mapped 14,826 yardangs in the region using a high-resolution digital elevation model (DEM) and satellite imagery. We classified yardangs as points using a two-stage decision rule based on morphology and spectral characteristics. Point pattern analysis shows that yardangs in the study area are not randomly distributed and commonly exhibit directional anisotropy in point pattern. The anisotropic pattern manifests as bands of closely-spaced yardangs oriented transverse to the dominant northwesterly wind direction. We hypothesize that banding is controlled by pre-existing antecedent topography in the bedrock, such as fumaroles or ridges associated with pyroclastic flow deposits. We present evidence from other locations on Earth and Mars to illustrate that the transverse banding is a common pattern in yardang landscapes. 相似文献
998.
999.
Chris Koen 《Astrophysics and Space Science》1987,132(1):53-56
An explanation for the observed correlation between the ratio (relative amplitude of flux variation)/(relative amplitude of radius variation) and the period of radial pulsation in cepheids is proposed. If the explanation is correct, correlations may be expected for other classes of pulsating stars with the general functional form determined by physical conditions in the atmosphere. 相似文献