GEOGRAPHERS: BIOBIBLIOGRAPHICAL STUDIES, 1977–2000     

PATRICK H. ARMSTRONG  GEOFFREY J. MARTIN 《Geographical review》2000,90(2):256-259

  相似文献   

MORALITY,SPACE, AND THE POWER OF WIND‐ENERGY LANDSCAPES     

MARTIN J. PASQUALETTI 《Geographical review》2000,90(3):381-394

ABSTRACT. Most of us have not known—or cared—where our electricity comes from. Our attitude is changing, however, as we turn toward wind energy, now the fastest‐growing renewable energy resource in the world. Because we cannot extract and transport the raw energy of the wind, reaping its many environmental benefits requires that we cope with the landscape presence of its development wherever it occurs. Sometimes this interferes with the value of open space, and sometimes it may be close to subdivisions. It is the immobility and very visibility of wind power that makes its presence unavoidable. In that regard it cannot be hidden underground, stored in tanks, or moved by trains. It is an energy resource that reminds us that our electricity comes from somewhere. The more we wish to tap the power of the wind, the less we will be able to avoid the responsibilities that our demand for energy brings. This necessary bargain, first evident near Palm Springs, California, is now being experienced wherever wind power is being developed.  相似文献   

INTEGRATED STUDIES OF HYDROLOGY AND WATER QUALITY IN GLACIERIZED CATCHMENTS     

MARTIN SHARP  KEITH RICHARDS 《水文研究》1996,10(4):475-478

  相似文献   

VELOCITY–DISCHARGE RELATIONSHIPS DERIVED FROM DYE TRACER EXPERIMENTS IN GLACIAL MELTWATERS: IMPLICATIONS FOR SUBGLACIAL FLOW CONDITIONS     

PETER W. NIENOW  MARTIN SHARP  IAN C. WILLIS 《水文研究》1996,10(10):1411-1426

Repeated dye tracer tests were undertaken from individual moulins at Haut Glacier d'Arolla, Switzerland, over a number of diurnal discharge cycles during the summers of 1989–1991. It was hoped to use the concepts of at-a-station hydraulic geometry to infer flow conditions in subglacial channels from the form of the velocity–discharge relationships derived from these tests. The results, however, displayed both clockwise and anticlockwise velocity–discharge hysteresis, in addition to the simple power function relationship assumed in the hydraulic geometry approach. Clockwise hysteresis seems to indicate that a moulin drains into a small tributary channel rather than directly into an arterial channel, and that discharges in the two channels vary out of phase with each other. Anticlockwise hysteresis is accompanied by strong diurnal variations in the value of dispersivity derived from the dye breakthrough curve, and is best explained by hydraulic damming of moulins or sub/englacial passageways. Despite the complex velocity–discharge relationships observed, some indication of subglacial flow conditions may be obtained if tributary channels comprise only a small fraction of the drainage path and power function velocity–discharge relationships are derived from dye injections conducted during periods when the supraglacial discharge entering the moulin and the bulk discharge vary in phase. Analyses based on this premise suggest that both open and closed channel flow occur beneath Haut Glacier d'Arolla, and that flow conditions are highly variable at and between sites.  相似文献   

The First Mesozoic Heterodactyl Bird from China   总被引：1，自引：1，他引：0  

ZHANG Zihui HOU Lianhai HASEGAWA Yoshikasu Jingmai O＇CONNOR Larry D. MARTIN Luis M. CHIAPPE 《《地质学报》英文版》2006,80(5):631-635

1 Introduction Enantiornithines were the dominant birds nearly worldwide throughout the entire span of the Cretaceous (Chiappe, 1995; Feduccia, 1996). The adaptive radiation of opposite birds is little known besides the disparity of rostral morphology in Boluochia (Zhou, 1995), Longipteryx (Zhang et al., 2001), Longirostravis ( Hou et al., 2004), and the presence of stomach contents that reflect a diversity of diets. Like the structure of rostrum, differentiation of the locomotor apparatu…  相似文献   

Pleistocene stratigraphy in the Dellen region, central Sweden     

ANN-MARIE ROBERTSSON  JAN-OLOV SVEDLUND  THOMAS ANDRÉN  MARTIN SUNDH 《Boreas: An International Journal of Quaternary Research》1997,26(3):237-260

Robertsson, A.-M., Svedlund, J.-O., Andrén, T. & Sundh, M. 1997 (September): Pleistocene stratigraphy in the Dellen region, central Sweden. Boreas, Vol. 26, pp. 237–260. Oslo. ISSN 0300–9483. The Pleistocene stratigraphy in the Dellen region, central Sweden was studied using field observations made during mapping of Quaternary deposits and fabric analyses in excavated sections. The lithostratigraphy was also studied by seismic refraction measurements, analyses of grain-size distribution and organic carbon content. Biostratigraphical methods applied were pollen and diatom analyses. A general outline of the Pleistocene stratigraphy in the area is presented. Three different till beds are identified, the lowermost suggested to have been deposited during the Saalian glaciation and the other two during the Weichselian glaciation. According to the interpretation of the stratigraphy, it is questioned whether the first Weichselian ice sheet did in fact reach the Dellen area. A clayey sediment sequence at Norra Sannas accumulated during an interglacial, probably the Eemian. Most of the interglacial vegetation succession is reflected in the identified pollen flora. An initial phase with a light-demanding forest of Belula and Pinus was followed by immigration of Alnus, Picea and scattered occurrences of Corylus. A freshwater diatom flora was identified dominated by plankton taxa, e.g. Aulacoseira italica, A. distans and Cyclotella spp. In the lower part of the sequence a brackish-marine flora was registered, representing accumulation in a bay of the Eemian Sea. Fine-grained sediments at the Sundson and Vastansjd sites are interpreted as rebedded Eemian sediments according to the pollen flora. An (Early Weichselian) interstadial age is suggested for sediments found at Bjuraker. Dating by the ¹⁴C- and OSL methods was carried out on the interglacial and interstadial sediments, respectively. The ages range from approximately 19000 to 92000 BP. Correlation of interglacial vegetation history with central Finland and other areas is discussed.  相似文献   

Topographic effects in stratified flows resolved by a spectral method     

KJELL ARILD ORVIK  MARTIN MORK 《地球，A辑:动力气象学与海洋学》1993,45(2):114-126

  相似文献   

A NEW HISTORY OF CANTERBURY. By S. Eldred-Grigg, John Mclndoe     

PETER PERRY 《New Zealand geographer》1984,40(2):121-121

  相似文献   

Impact of drought stress and other factors on seasonal land biosphere CO₂ exchange studied through an atmospheric tracer transport model     

WOLFGANG KNORR  MARTIN HEIMANN 《Tellus. Series B, Chemical and physical meteorology》1995,47(4):471-489

  相似文献   

Promoting Business Networks     

SEAN GOLDFINCH  MARTIN PERRY 《New Zealand geographer》1997,53(1):41-46

Interest in the role cooperative networks can play in small business development is increasing. Evidence from a survey of three network promoting small business associations based in three different cities is examined and a number of different ways the agencies could deliver their services are suggested. Two networking initiatives by the New Zealand Trade Development Board are then considered. It is concluded that individual networking initiatives need to be developed and evaluated as part of a broad policy push to facilitate the development of an environment more conducive to business cooperation.  相似文献