Coupled lateral-torsional behaviour of frame structures under earthquake loading     

M. R. Maheri  A. M. Chandler  R. H. Bassett 《地震工程与结构动力学》1991,20(1):61-85

A series of parametrically defined experimental model structures has been tested under earthquake base loading using the SERC national U.K. earthquake simulator. The models have been designed with variable ratios of torsional to lateral stiffness, and with both symmetric and asymmetric mass distributions. This paper first describes the tests carried out to determine the basic dynamic model properties and the establishment of idealized analytical models which give accurate predictions of model behaviour under steady-state loading and free-vibration conditions. Secondly, a detailed discussion is made of the two highly coupled structural models having uncoupled torsional to lateral frequency ratio R_f = 1.2, commenting on the ability of the modal analysis procedures to predict accurately the maximum recorded responses. It is concluded that the theory underestimates the significance of the fundamental torsional mode of vibration in the combined structural response, and overestimates the contribution of the first lateral mode. These effects compensate each other on the side of the structure which is most severely affected by torsional response, but produce large inaccuracies on the side of the building which is commonly assumed to be affected beneficially by torsional coupling.  相似文献   

Late Pleistocene climate inferences from a water balance model of Jakes Valley,Nevada (USA)     

Cornelia Barth  Douglas P. Boyle  Benjamin J. Hatchett  Scott D. Bassett  Christopher B. Garner  Kenneth D. Adams 《Journal of Paleolimnology》2016,56(2-3):109-122

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ECONOMIC DEVELOPMENT IN THE HUMID TROPICS     

I.G. Bassett 《New Zealand geographer》1969,25(1):72-73

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Slim pickings: Fairtrade cotton in West Africa     

Thomas J. Bassett 《Geoforum》2010,41(1):44-55

This paper examines the extent to which certified fairtrade cotton programs in West Africa present an alternative to the conventional cotton economy. Two fairtrade programs operating in Burkina Faso and Mali serve as case studies. The paper argues that fairtrade cotton fails to offer an alternative to conventional cotton because it works within the same commodity chain that impoverishes farmers in the first place. Cotton grower organizations seek more power within the conventional cotton sector to increase incomes and improve the living standards of all cotton growers. They are also active at the international level to eliminate the inequities of international trade. It is in these arenas that cotton growers are struggling to improve their incomes and livelihoods. Fairtrade does not address these fundamental inequities and power relations. The slim pickings of these programs are further evident in the very small amount of cotton produced and marketed as fair trade. Plans to expand production from less than 1% to 10% by 2012 are unrealistic in light of the introduction of genetically modified cotton and the limited market demand for fairtrade cotton. Despite these limitations, fairtrade cotton programs are producing some positive effects, notably women’s participation in cash crop cultivation, higher cotton quality, and the diffusion of organic farming techniques. An innovative direct marketing agreement linking the National Cotton Growers’ Union of Burkina Faso with the US women’s apparel company Victoria’s Secret indicates that alternative trading relations can be constructed outside the conventional commodity chain.  相似文献   

Sounding the dark cosmos     

Bruce A Bassett  Bob Nichol  Daniel J Eisenstein 《Astronomy& Geophysics》2005,46(5):5.26-5.29

Bruce Bassett, Bob Nichol and Daniel J Eisenstein explain why the Wide-Field Multi-Object Spectrograph will need to look so far into the universe, over such a wide area, in order to map sound waves from the dawn of time.  相似文献   

Breaking global temperature records after Mt. Pinatubo     

Gilbert W. Bassett Jr.  Zhiyong Lin 《Climatic change》1993,25(2):179-184

The probability of setting global temperature records is reconsidered in light of cooling due to the Mt. Pinatubo eruption. The cooling resets temperature by moving it away from the top of its 100-year range. Depending on the statistical model for temperature, this reset can lead to a much lower probability for a record in the next few years. The exercise illustrates how record setting depends on the underlying model, the current record value, and - if there is serial correlation- the current temperature.  相似文献   

Optimizing baryon acoustic oscillation surveys – I. Testing the concordance ΛCDM cosmology     

David Parkinson  Chris Blake  Martin Kunz  Bruce A. Bassett  Robert C. Nichol  Karl Glazebrook 《Monthly notices of the Royal Astronomical Society》2007,377(1):185-197

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VON THUNEN'S 'ISOLATED STATE'. An English Edition of 'Dcr Isolierte Staat' by Johann Heinrich Von Thunen     

I. G. Bassett 《New Zealand geographer》1967,23(1):91-92

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High-pressure polymorphism of FeO? An alternative interpretation and its implications for the Earth's core     

Lin-gun Liu  Pouyan Shen  William A. Bassett 《Geophysical Journal International》1982,70(1):57-66

Summary. It has been reported that no stoichiometric FeO can be formed at temperatures above about 600°C regardless of pressure. The stoichiometry of Fe _X O quenched from static high pressure and temperature experiments appears to decrease with increasing pressure in the range 100–300kbar. On the basis of these observations, we have re-interpreted the recent shock results on Fe_0.94O, and have found that the Hugoniot data can be reasonable interpreted by the same shift in stoichiometry as observed in the static high-pressure experiments instead of a first-order transformation as proposed. If oxygen is assumed to be the light component of the outer core, the outer core can be chemically homogeneous only if the stoichiometry of Fe _X O decreases with increasing pressure. A constant stoichiometry would demand that the oxygen content decreases by a factor of 2 from the top to the bottom of the outer core. A chemically homogeneous outer core is consistent with a convecting outer core.  相似文献   

Geochemical tracers to evaluate hydrogeologic controls on river salinization     

Moore SJ  Bassett RL  Liu B  Wolf CP  Doremus D 《Ground water》2008,46(3):489-501

The salinization of rivers, as indicated by salinity increases in the downstream direction, is characteristic of arid and semiarid regions throughout the world. Historically, salinity increases have been attributed to various mechanisms, including (1) evaporation and concentration during reservoir storage, irrigation, and subsequent reuse; (2) displacement of shallow saline ground water during irrigation; (3) erosion and dissolution of natural deposits; and/or (4) inflow of deep saline and/or geothermal ground water (ground water with elevated water temperature). In this study, investigation of salinity issues focused on identification of relative salinity contributions from anthropogenic and natural sources in the Lower Rio Grande in the New Mexico-Texas border region. Based on the conceptual model of the system, the various sources of water and, therefore, salinity to the Lower Rio Grande were identified, and a sampling plan was designed to characterize these sources. Analysis results for boron (delta(11)B), sulfur (delta(34)S), oxygen (delta(18)O), hydrogen (delta(2)H), and strontium ((87)Sr/(86)Sr) isotopes, as well as basic chemical data, confirmed the hypothesis that the dominant salinity contributions are from deep ground water inflow to the Rio Grande. The stable isotopic ratios identified the deep ground water inflow as distinctive, with characteristic isotopic signatures. These analyses indicate that it is not possible to reproduce the observed salinization by evapotranspiration and agricultural processes alone. This investigation further confirms that proper application of multiple isotopic and geochemical tracers can be used to identify and constrain multiple sources of solutes in complex river systems.  相似文献