AN ILLUSTRATIVE STUDY ON LOCAL LANDSCAPEAND ITS LONG-TERM CHANGES BASED ON IKONOS AND HISTORICAL AERIAL PHOTO   总被引：2，自引：0，他引：2  

RUANRen-zong ErieCELLISt 《中国地理科学(英文版)》2004,14(2):162-169

Nowadays, the research works on landscape at fine scales using high-resolution images are uncommon.This research is based on the analysis of the combination of remote sensing data (1KONOS imagery acquired in 2002 and historical aerial photo taken in 1942). In the paper, the ecotopes in Qiujiadou and Xishao villages in Yixing City of Jiangsu Province in 1942 and 2002 were compared and landscape changes as well as the causes of the considerable changes were analyzed. It was found that the ecotope changes were at greater level in some aspects such as water surface and perennial vegetation coverage etc. This study at fine scale is globally significant for the rural areas, especially for the subsistence agricultural land, which occupies larger percentage in the earth. And it analyzes the structure of landscape based on a new landscape classification system--stratifications method.  相似文献   

Galaxy spectral parametrization in the 2dF Galaxy Redshift Survey as a diagnostic of star formation history     

Darren S. Madgwick  Rachel Somerville  Ofer Lahav  Richard Ellis 《Monthly notices of the Royal Astronomical Society》2003,343(3):871-879

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Numerical simulations of weak lensing measurements     

David J. Bacon  Alexandre Refregier  Douglas Clowe  Richard S. Ellis 《Monthly notices of the Royal Astronomical Society》2001,325(3):1065-1074

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Coronal mass ejection associated with the stationary post-flare arch of 21–22 May 1980     

Marie K. McCabe  Zdeněk F. Švestka  Russell A. Howard  Bernard V. Jackson  Neil R. Sheeley Jr. 《Solar physics》1986,103(2):399-408

By using a combination of X-ray (HXIS), H (Haleakala), white-light corona (Solwind), and zodiacal light (Helios) images on 21–22 May, 1980 we demonstrate, and try to explain, the co-existence of a coronal mass ejection with a stationary post-flare coronal arch. The mass ejection was seen, both by Solwind and Helios, in prolongation of the path of a powerful spray, whereas the active region filament did not erupt. A tentative comparison is made with other occurrences of stationary, or quasi-stationary post-flare coronal arches.  相似文献   

激光拉曼光谱法分析多种显微组分荧光变化及其应用   总被引：1，自引：1，他引：0  

李志明  施伟军  SHERWOOD Neil  刘文斌  蒋宏 《岩矿测试》2008,27(5):341-345

利用激发488 nm激光的氩离子激光器作为RENISHAW inVia型激光拉曼光谱仪的光源,建立了多种显微组分荧光变化(FAMM)分析方法,并对镜质体反射率明显抑制的东营凹陷有效烃源岩进行了测定。结果表明,东营凹陷有效烃源岩的有机质类型越好,镜质体反射率抑制程度越高,有效烃源岩的真实成熟度应主要处于0.64%~1.30%,而不是实测镜质体反射率所反映的0.37%~1.10%。  相似文献   

Kinetics of Cd sorption, desorption and fixation by calcite: A long-term radiotracer study     

Imad A.M. Ahmed  Neil M.J. Crout  Scott D. Young 《Geochimica et cosmochimica acta》2008,72(6):1498-1512

Time-dependent sorption and desorption of Cd on calcite was studied over 210 days utilizing ¹⁰⁹Cd as a tracer to distinguish between ‘labile’ and ‘non-labile’ forms of sorbed Cd. Stabilizing the calcite suspensions for 12 months under atmospheric P_CO2 and controlled temperature was necessary to reliably follow Cd dynamics following initial sorption. Results revealed time-dependant Cd sorption and marked desorption hysteresis by calcite under environmentally relevant conditions. Data obtained were fitted to a first-order kinetic model and a concentric shell diffusion model. Both models described the progressive transfer of Cd²⁺ to a less reactive form within calcite and subsequent desorption of Cd subject to different initial contact times. The kinetic model provided a better fit to the combined sorption and desorption data (R² = 0.992). It differentiates between two ‘pools’ of sorbed Cd²⁺ on calcite, ‘labile’ and ‘non-labile’, in which labile sorbed Cd is in immediate equilibrium with the free Cd²⁺ ion activity in solution whereas non-labile Cd is kinetically restricted. For the diffusion model (R² = 0.959), the rate constants describing Cd dynamics in calcite produced a half-life for Cd desorption of ∼175 d, for release to a ‘zero-sink’ solution. Results from this study allow comment on the likely mechanisms occurring at the calcite surface following long-term Cd sorption.  相似文献   

Effective livelihood adaptation to climate change disturbance: Scale dimensions of practice in Mozambique   总被引：2，自引：0，他引：2  

Henny Osbahr  Chasca Twyman  W. Neil Adger  David S.G. Thomas 《Geoforum》2008,(6):1951-1964

Natural resource-dependent societies in developing countries are facing increased pressures linked to global climate change. While social-ecological systems evolve to accommodate variability, there is growing evidence that changes in drought, storm and flood extremes are increasing exposure of currently vulnerable populations. In many countries in Africa, these pressures are compounded by disruption to institutions and variability in livelihoods and income. The interactions of both rapid and slow onset livelihood disturbance contribute to enduring poverty and slow processes of rural livelihood renewal across a complex landscape. We explore cross-scale dynamics in coping and adaptation response, drawing on qualitative data from a case study in Mozambique. The research characterises the engagements across multiple institutional scales and the types of agents involved, providing insight into emergent conditions for adaptation to climate change in rural economies. The analysis explores local responses to climate shocks, food security and poverty reduction, through informal institutions, forms of livelihood diversification and collective land-use systems that allow reciprocity, flexibility and the ability to buffer shocks. However, the analysis shows that agricultural initiatives have helped to facilitate effective livelihood renewal, through the reorganisation of social institutions and opportunities for communication, innovation and micro-credit. Although there are challenges to mainstreaming adaptation at different scales, this research shows why it is critical to assess how policies can protect conditions for emergence of livelihood transformation.  相似文献   

Ground-Water Studies— Chicagoland Deep Tunnel System     

Istavros S. Papadopulos  William R. Larsen  Forrest C. Neil 《Ground water》1969,7(5):3-15

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Advances in the fatigue assessment of wire ropes     

Alan G. Paton  Neil F. Casey  Joe Fairbairn  William M. Banks   《Ocean Engineering》2001,28(5)

This paper presents the findings from an in-depth analysis of the (axial) stiffness data recorded during tension–tension fatigue tests on wire ropes, particularly in relation to how changes in stiffness during testing relate to changes in rope strength. A linear relationship between stiffness and strength is shown to exist and a methodology presented for quantifying residual strength with applied cycles. New lower bound fatigue lines for six-strand rope and spiral strand are presented which are based on a 10% loss of strength. These new lines have the advantage of having been established using a common discard criterion for wire ropes.  相似文献   

A giant three-stage submarine slide off Norway   总被引：8，自引：0，他引：8  

Tom Bugge  Stein Befring  Robert H. Belderson  Tor Eidvin  Eystein Jansen  Neil H. Kenyon  Hans Holtedahl  Hans Petter Sejrup 《Geo-Marine Letters》1987,7(4):191-198

One of the largest submarine slides known, The Storegga Slide, is located on the Norwegian continental margin. The slide is up to 450 m thick and has a total volume of about 5,600 km3. The headwall of the slide scar is 290 km long and the total run-out distance is about 800 km. The slide involved sediments of Quaternary to Early Tertiary age and occurred in three stages. Earthquakes combined with decomposition of gas hydrates are believed to be the main triggering agents for the slides. The first slide event is tentatively dated to be about 30,000 to 50,000 years B.P. and the two last major events are dated to be at 6,000 to 8,000 years B.P.  相似文献