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71.
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Na Liu Thomas N. Buckley Xinguang He Xinping Zhang Cicheng Zhang Zidong Luo Hailong Wang Nasrin Sterling Huade Guan 《水文研究》2019,33(12):1670-1685
Plant transpiration depends on environmental conditions, and soil water availability is its primary control under water deficit conditions. In this study, we improve a simplified process‐based model (hereafter “BTA”) by including soil water potential (ψsoil) to explicitly represent the dependence of plant transpiration on root‐zone moisture conditions. The improved model is denoted as the BTA‐ψ model. We assessed the performance of the BTA and BTA‐ψ models in a subtropical monsoon climate and a Mediterranean climate with different levels of water stress. The BTA model performed reasonably in estimating daily and hourly transpiration under sufficient water conditions, but it failed during dry periods. Overall, the BTA‐ψ model provided a significant improvement for estimating transpiration under a wide range of soil moisture conditions. Although both models could estimate transpiration (sap flow) at night, BTA‐ψ was superior to BTA in this regard. Species differences in the calibrated parameters of both models were consistent with leaf‐level photosynthetic measurements on each species, as expected given the physiological basis of these parameters. With a simplified representation of physiological regulation and reasonable performance across a range of soil moisture conditions, the BTA‐ψ model provides a useful alternative to purely empirical models for modelling transpiration. 相似文献
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Richard L. Pfeffer William W. Fowlis Jay Fein James Buckley 《Pure and Applied Geophysics》1970,81(1):263-271
Summary The transition between axisymmetric and wave convection in a rotating, cylindrical annulus of fluid subjected to a horizontal temperature gradient is usually determined in laboratory experiments by visually observing the motion of tracer particles at the top surface of the fluid. More recent transition determinations by means of small transducers suspended within the body of the fluid give evidence of quantitative disagreement with the visual method. The dgree of disagreement and experimental details are discussed in this note.Contribution No. 20 of the Geophysical Fluid Dynamics Institute. 相似文献
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It has been suggested that Porcupine Ridge, west of Ireland, represents a continental fragment displaced westwards relative to Europe at an early stage in the opening of the North Atlantic. This hypothesis presents difficulties, particularly in relation to the magnetic evidence for the onset of seafloor spreading at these latitudes. However, the structure of the Irish continental margin, so far as it is known, appears consistent with a westward rotation of Porcupine Ridge by some 23°; and there are still grounds for supposing that the adjacent Rockall Trough may represent a locus of Mesozoic seafloor spreading with which the rotation could have been associated. 相似文献
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A method is described for etching iron meteorites by heating at 350 °C in dry chlorine gas. Iron is volatilized from low-nickel iron phases, e.g. kamacite, and the residual non-volatile chlorides are removed by solution. The study of the morphological character of the exposed phosphides on 16 specimens from Group IA and IIA showed no distinctive habit restricted to either group. 相似文献
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