The geology of the Torquay district     

W.G. Shannon 《Proceedings of the Geologists' Association. Geologists' Association》1928,39(2):103-IN2

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What risks matter? Public views about assisted migration and other climate-adaptive reforestation strategies     

Guillaume Peterson St-Laurent  Shannon Hagerman  Robert Kozak 《Climatic change》2018,151(3-4):573-587

The world’s forests play an important role in regulating climate change through their capacity to sequester carbon. At the same time, they are also increasingly vulnerable to the impacts of climate change. In the western Canadian province of British Columbia, changes in temperature, precipitation, and disturbance regimes are already impacting forests. In response to these observed and anticipated changes, adapted reforestation practices are being developed and proposed as a means to help forest ecosystems adjust to changing climatic conditions. One such practice under consideration is assisted migration—planting species within or outside of the native historical range into areas that are anticipated to be climatically suitable in the future. We used a survey of British Columbia’s population at large (n?=?1923) to quantify levels of support for a range of potential reforestation options (including assisted migration) to adapt to climate change, and to explore what factors can help predict this support. Our findings reveal that the likely location of potential public controversy resides not with the potential implementation of assisted migration strategies per se, but rather with assisted migration strategies that involve movement of tree species beyond their native range.  相似文献   

两岸地震记录交流初探     

李咸亨  谢礼立 《地震工程与工程振动》1995,15(3):1-3

本文指出了海峡两岸在测量地震震级中存在的差异，并对此开展深入研究，提出了建议。  相似文献   

Atmospheric chemistry of alkanes     

Carter  William P. L.  Atkinson  Roger 《Journal of Atmospheric Chemistry》1985,3(3):377-405

The reactions of the alkanes under atmospheric conditions and in the presence of oxides of nitrogen are reviewed and evaluated. Particular emphasis is placed upon their subsequent reactions after the initial OH radical reaction under conditions where the alkyl peroxy radicals produced react predominantly with NO, rather than with HO₂ and/or RO₂ radicals. Methods are discussed for estimating the overall OH radical rate constants, the number of molecules of NO consumed per alkane molecule reacted, and the products formed and their yields.  相似文献   

Creep of crystals: J.P. Poirier,Cambridge University Press, 1985, xii + 260 pp., £27.50, US$ 49.50, ISBN 0-521-26177-5     

B.K. Atkinson 《Physics of the Earth and Planetary Interiors》1985,41(1):70-71

Fractional crystallization behaviour of a magma ocean extending to lower mantle depths was deduced from estimations of melting relations for the deep mantle and the density relationships between ultrabasic liquid and mantle minerals. The accretional growth of the Earth necessarily involves a molten zone (magma ocean) in the outer layer of the growing Earth. The fractionation by melting during accretion results in primary stratification composed of a molten ultrabasic upper mantle (magma ocean), a perovskite-rich lower mantle, and an iron core. A certain amount of Al₂O₃ and CaO was removed from the magma ocean and retained in the lower mantle due to eclogite fractionation in the early stage of accretion and the perovskite fractionation in the later stage of accretion. Models of the stratification of the upper mantle arising from fractional crystallization of the magma ocean and subsequent convective disturbance were deduced on the basis of estimations of melting relations for the deep mantle and the density relationships between the ultrabasic liquid and mantle minerals. The stratification of the mantle, which is consistent with geophysical constraints is as follows; the upper mantle is composed of two layers, the upper olivine-rich layer and the lower garnet-rich layer with a thickness around 200 km, and the lower mantle with a perovskite-rich composition. In this model, both the 400 and 650 km discontinuities are the chemical boundaries.  相似文献   

The soil resource: Origin and behaviour. H. Jenny,Ecological Studies Vol. 37, Springer-Verlag, 1980. No. of pages: 377. Price: £15.40     

Ken Atkinson 《地球表面变化过程与地形》1982,7(3):296-297

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The gas-phase reaction of ClONO2 with hydrogen chloride     

Roger Atkinson  Sara M. Aschmann  Ernesto C. Tuazon  Mark A. Goodman  Arthur M. Winer 《Journal of Atmospheric Chemistry》1987,5(1):83-90

The gas-phase reaction of ClONO₂ with HCl was investigated using two large-volume environmental chambers with analysis by in situ long pathlength Fourier transform infrared absorption spectroscopy. In these chambers the reaction was observed to proceed, at least in part, by heterogenous routes, and an upper limit to the rate constant for the homogeneous gas-phase reaction of geneous routes, and an upper limit to the rate constant for the homogeneous gas-phase reaction of $$k\left( {{\text{ClONO}}_{\text{2}} + {\text{HCl}}} \right) < 1.5 \times 10^{ - 19} {\text{ cm}}^{\text{3}} {\text{ molecule}}^{{\text{ - 1}}} {\text{ s}}^{{\text{ - 1}}}$$ Was derived at 298±2K. Assuming that this room-temperature upper limit to the rate constant is applicable to stratospheric temperatures, this homogeneous gas-phase reaction can be estimated to be of negligible importance as a ClONO₂ loss process in the stratosphere.  相似文献   

Physics of the earthquake focus,edited by M. A. Sadovskii,A. A. Balkema,Rotterdam, 1986. No. of pages: 250. Price: £20     

B. K. Atkinson 《地震工程与结构动力学》1986,14(5):819-819

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A fracture mechanics study of subcritical tensile cracking of quartz in wet environments   总被引：6，自引：0，他引：6  

Barry Kean Atkinson 《Pure and Applied Geophysics》1979,117(5):1011-1024

Load relaxation and cross-head displacement rate-change experiments have been used to establish log₁₀ stress intensity factor (K) versus log₁₀ crack velocity (v) diagrams for double torsion specimens, of synthetic quartz cracked on thea plane in liquid water and moist air.For crack propagation normal toz and normal tor at 20°C,K _Ic (the critical stress intensity factor) was found to be 0.852±0.045 MN·m^–3/2 and 1.002±0.048 MN·m^–3/2, respectively.Subcritical crack growth at velocities from 10^–3 m·s^–1 to 10^–9 m·s^–1 at temperatures from 20°C to 80°C is believed to be facilitated by chemical reaction between the siloxane bonds of the quartz and the water or water vapour of the environment (stress corrosion). The slopes, of isotherms in theK-v diagrams are dependent upon crystallographic orientation. The isotherms have a slope of 12±0.6 for cracking normal tor and 19.9±1.7 for cracking normal toz. The activation enthalpy for crack propagation in the former orientation in liquid water at temperatures from 20°C to 80°C is 52.5±3.8 kJ·mole^–1.A discussion is presented of the characteristics of theK-v diagrams for quartz.  相似文献   

Stress-dependent morphological features on fracture surfaces of quartz and glass   总被引：1，自引：0，他引：1  

M.G. Norton  B.K. Atkinson 《Tectonophysics》1981,77(3-4)

Stress dependent morphological features have been found on tensile fracture surfaces of natural Brazilian quartz and synthetic quartz specimens which were flexed in air at room temperature. These features are similar to stress dependent morphological features found on fracture surfaces of pyrex, soda-lime and lead glass when deformed in similar experiments. For glass, the relevant morphological feature is the fracture “mirror”, a planar region surrounding the initial flaw. Stress dependent index features chosen for measurement in quartz depend upon the crystallographic orientation on the fracture surface. Their development is related to the crack-system energy but, in contrast to glass, the features are not directly related to crack branching. The experimental results follow an equation of the form: where σ_f is the fracture stress, r* is the size of a particular morphological feature (e.g. the “mirror” radius in the case of glass) and A* is a constant.From the magnitudes of A* and the fracture toughness determined in these experiments we conclude that the natural Brazilian quartz used in this study has significantly higher resistance to fracture than synthetic quartz.  相似文献