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991.
Due to the limitation of site number, manpower and material resources, it is hard to gain a deep understanding of the plane distribution and internal structure of the thermal conditions by routine methods to study the thermal landscape characteristics of the ground surface. Using remote sensing method to study and analyze heat island effect has many advantages, such as high resolution, wide coverage and dense samples. In order to study, in advance and synchronously, the thermal distribution ch… 相似文献
992.
993.
Geodynamic characteristics of tectonic extension in the northern margin of South China Sea 总被引:1,自引:0,他引:1
Based on the geothermal and gravitation methods, this paper investigated the rheological and thermal structure of the lithosphere
under the northern margin of South China Sea. The result shows that the temperature of the upper crust is 150–300°C lower
than that of the lower crust, and the viscous coefficient of the upper crust is 2–3 orders of magnitude larger than that of
the lower crust. It reveals that the upper crust is characterized by brittle deformation while the lower crust by ductile
deformation. A channel of lower-viscosity should be formed between the upper and lower crust when the lithosphere is scattered
and spreads out toward ocean from northwest to southeast along the northern margin of South China Sea. And, a brittle deformation
takes place in the upper part of the lithosphere while a ductile deformation takes place in the lower part of the lithosphere
due to different viscous coefficients and temperature. The layered deformation leads the faulted blocks to rotate along the
faulting and the marginal grabens to appear in the northern margin of South China Sea in Cenozoic tectonic expansion. 相似文献
994.
Non-hibernating mammals that live in seasonal and arid environments change their non-shivering thermogenesis (NST) capacity to maintain homeothermy. Metabolic capabilities of animals, such as NST, are considered adaptive plastic traits because they have a broad range of possible phenotypes with different ambient temperatures (i.e. the reaction norm). Consequently, we determined the reaction norm for NST in Octodon degus (Bennett, 1832; mb=189 g) andPhyllotis darwini (Waterhouse, 1837; mb=61 g) from the mesic habitat of central Chile, and inPhyllotis xanthopygus (Waterhouse, 1837; mb=67 g) from the high Andean plains of northern Chile, an arid and seasonal habitat. Octodon degus showed a 22% increase in NST with thermal acclimation, whereas P. xanthopygus showed a 112% increase, and P. darwini showed a 117% increase in NST, being the largest change observed. These results are in agreement with our hypothesis of evolutionary inertia, which states that observed metabolic plasticity in Phyllotis species is consequence of their high Andean origin, in spite of the fact the actual habitat ofP. darwini is the less seasonal central valley of Chile. 相似文献
995.
This paper investigates the nonlinear prediction of monthly rainfall time series which consists of phase space con-tinuation of one-dimensional sequence, followed by least-square determination of the coefficients for the terms of the time-lag differential equation model and then fitting of the prognostic expression is made to 1951-1980 monthly rainfall datasets from Changsha station Results show that the model is likely to describe the nonlinearity of the an-nual cycle of precipitation on a monthly basis and to provide a basis for flood prevention and drought combating for the wet season. 相似文献
996.
Recent developments in stochastic and statistical methods in hydrology and environmental engineering presented in the upcoming sequence of research papers are evaluated, compared and put into proper perspective. These papers are being published as a memorial to Professor T. E. Unny who was a founding Editor of the journalStochastic Hydrology and Hydraulics. As explained in this introductory paper, other activities that took place to celebrate Professor Unny's lifetime academic accomplishments include an international conference held in his honor at the University of Waterloo in June, 1993 and the publication of a four-volume conference proceedings in 1994. 相似文献
997.
Abstract Apatite and zircon fission-track (FT) analyses of the Shimanto accretionary complex and its vicinities, southwest Japan, unraveled the episodic material migration of the deep interiors of the accretionary complex. Apatite data with 100°C closure temperature (Te) generally indicate ~10 Ma cooling throughout the Shimanto complex. In contrast, zircon data with 260°C Te exhibit a wide range of apparent ages as a consequence of paleotemperature increase to the zircon partial annealing zone. In the Muroto and Kyushu regions, maximum temperatures tend to have been higher in the northern, older part of the complex, with indistinguishable temperature differences between coherent and melange units adjacent to each other. It thus suggests, along with vitrinite reflectance data, that older accretionary units occurring to the north sustain greater maximum burial during the accretion-burial-exhumation process. Zircon data suggest two cooling episodes: ~70 Ma cooling at widespread localities in the Cretaceous Shimanto Belt and Sambagawa Belt, and ~15 Ma cooling in the central Kii Peninsula. The former is consistent with 40Ar/39Ar cooling ages from the Sambagawa Belt, whereas the latter slightly predates the widespread 10 Ma apatite cooling ages. These data imply that the extensive material migration and exhumation took place in and around the Shimanto complex in Late Cretaceous as well as in Middle Miocene. Considering tectonic factors to control evolution of accretionary complexes, the episodic migration is best explained by accelerated accretion of sediments due to increased sediment influx at the ancient Shimanto trench, probably derived from massive volcano-plutonic complexes contemporaneously placed inland. Available geo- and thermochronologic data suggest that extensive magmatism triggered regional exhumation twice in the past 100 Ma, shedding new light on the cordilleran orogeny and paired metamorphism concepts. 相似文献
998.
Application of a Shape-Preserving Advection Scheme to the Moisture Equation in an E-grid Regional Forecast Model 总被引:20,自引:1,他引:20
This paper presents a methodology which is very useful to design shape-preserving advection finite difference scheme on general E-grid horizontal arrangement of variables through introducing a two-step shape-preserving positive definite advection scheme in the moisture equation of the LASG-REM (LASG regional E-grid eta-coordinate forecast model). By trial-forecasting six local heavy raincases, the efficiency of the shape-preserving advection scheme in practical application has been examined. The LASG-REM with the shape-preserving advection scheme has a good forecasting ability for local precipitation. 相似文献
999.
本文论述了渍害遥感识别的主要标志,通过土壤热惯量、土壤含水量及土壤温度等渍害相关因子的讨论,阐明了渍害遥感识别的基本原理及几种主委方法。由于渍害涉及诸多因素,本文给出了以地学相关分析为基础的渍害判别模型。本研究表明,用遥感方法研究渍害是切实可行的。 相似文献
1000.
雷州半岛硅藻土煅烧中的结构变化 总被引:5,自引:4,他引:5
本文应用X射线衍射、红外光谱、扫描电镜等手段,对广东海康、徐闻的硅藻土在煅烧过程中热结构变化进行了探讨。结构表明,煅烧使硅藻内部矿物的微观结构发生变化而引起形变,主要为SiO2从无序含水的蛋白石转变为有序的方石英晶体。形变温度随其硅藻的种类和杂质不同而各异。本研究为这两地硅藻土的开发提供了科学依据。 相似文献