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101.
WANG Runyuan ZHANG Qiang ZHAO Hong WANG Heling WANG Chunling 《Acta Meteorologica Sinica》2012,26(2):250-259
The heat storage terms over an ideal(non-vegetated) horizontal desert surface may be very important and easily neglected in surface energy balance studies.In this paper,based on a field experiment over the Gobi Desert in the middle part of the Hexi Corridor in Northwest China(39 05 N,100 16 E;1457-m elevation),we studied the energy budget closure and evaluated the contribution of the heat storage terms to the closure of the surface energy balance.There were imbalances of 8% and 15% in summer and winter,respectively,if the heat storage terms were not taken into account.For both seasons,a nearly perfect result of the surface energy closure(99%) was obtained by inclusion of the estimates of heat storage terms.The soil heat storage term improved the surface energy imbalance by about 6% in summer and 13% in winter,and the air enthalpy storage term improved it by about 0.6% in summer and 1% in winter,while the contribution of the atmospheric moisture changes could be ignored. 相似文献
102.
M. Sachpazi A. Galv M. Laigle A. Hirn E. Sokos A. Serpetsidaki J.-M. Marthelot J.M. Pi Alperin B. Zelt B. Taylor 《Tectonophysics》2007,440(1-4):53-65
In this paper we expand over the whole of central Greece, the Moho map centered on the Gulf of Corinth from tomographic inversion of PmP traveltime profile data recorded by several tens of temporary stations. Our approach is based on Pn, Moho refracted waves, from a large regional earthquake recorded by both temporary stations and the permanent Hellenic network. The Moho map shows the large Moho depth under the Hellenides belt. It also highlights the shallower Moho domain towards the Aegean Sea south and east of the Corinth Gulf. The domain of shallow Moho is limited along a NE–SW prolongation ahead of the North Anatolian Fault, from the North Aegean Trough to the western tip of the Gulf of Corinth towards the Gulf of Patras. The Pn time-terms provide corrections for the permanent stations that can be used together with the 1D velocity–depth model for a first-order compensation of lateral heterogeneity and contribute to the accurate and fast location of earthquake hypocenters. As a test we relocated the 1995 Aigion earthquake in this way, using only the sparse data of the permanent stations. Hypocentral coordinates then shift close to those derived by a dedicated dense array deployed after the earthquake, implying improvement of the routine location. 相似文献
103.
104.
地质论文撰写中值得注意的若干问题 总被引:1,自引:0,他引:1
来稿中经常发现在地质学术术语、相关符号及计量单位的使用以及数字、文字的规范化表述等方面存在一些普遍性的问题,它在某种程度上影响着论文的整体质量,因而有必要对其引起足够的重视。 相似文献
105.
106.
Use of fuzzy synthetic evaluation for assessment of groundwater quality for drinking usage: a case study of Southern Haryana,India 总被引:1,自引:0,他引:1
Bhupinder Singh Sudhir Dahiya Sandeep Jain V. K. Garg H. S. Kushwaha 《Environmental Geology》2008,54(2):249-255
A method based on concept of fuzzy set theory has been used for decision-making for the assessment of physico-chemical quality
of groundwater for drinking purposes. Conventional methods for water quality assessment do not consider the uncertainties
involved either in measurement of water quality parameters or in the limits provided by the regulatory bodies. Fuzzy synthetic
evaluation model gives the certainty levels for the quality class of the water based on the prescribed limit of various regulatory
bodies and opinion of the experts from the field of drinking water quality. In this paper, application of fuzzy rule based
optimization model is illustrated with twenty groundwater samples from Sohna town of Gurgaon district of Southern Haryana,
India. These samples were analysed for 15 different physico-chemical parameters, out of them nine important parameters were
used for the quality assessment using fuzzy synthetic evaluation approach. From this study, it has been concluded that all
the water samples are in acceptable category whose certainty level ranges from 44 to 100%. Water from these sources can be
used for the drinking purposes if alternate water source is not available without any health concern on the basis of physico-chemical
characteristics. 相似文献
107.
Seppo Mikkola 《Celestial Mechanics and Dynamical Astronomy》1998,68(3):249-255
The inclusion of non-canonical perturbations in symplectic integration schemes has been discussed. A rigorous derivation of
an analog for theWisdom–Holman (1991) method, such that velocity dependent forces can be included, has been outlined. This
is done both by using the δfunction formalism and also by means of formal Hamiltonization. Application to the relativistic
corrections in Solar System integrations is discussed as an example. Numerical experiments confirm the usefulness of the method.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
108.
通过对帕米尔东北侧伽师及其周边地区两条深地震测深剖面S波资料的处理计算,结合P波研究结果,得到了S波二维地壳速度结构和波速比(vP/vS)分布.研究表明:① 塔里木块体平均地壳波速比明显高于西昆仑和天山褶皱带,显示了坚硬、稳定地壳物性特征.下地壳正常偏低的波速比(泊松比)值,说明塔里木块体的下插是该地区地壳运动的主要特征;② 天山褶皱带上地壳岩层相对较软,易于在应力作用下断裂破碎和应力能量释放,是其小震密集分布的重要构造因素;③ 伽师附近正处在下地壳C界面和壳幔边界的上隆顶部或拐点上,是强震群发生的深部构造背景.上地壳中下部的块体边界附近波速比值的交错变化和接触面复杂形态的存在,形成了伽师强震群出现的特殊构造环境.震源处波速比相对较高,剪切模量较小,可能是伽师强震群应力降偏低的主要原因. 相似文献
109.
Robust path-following of underactuated ships: Theory and experiments on a model ship 总被引:1,自引:0,他引:1
A method is proposed to design a new global controller that forces an underactuated ship to follow a reference path under disturbances induced by wave, wind and ocean-current. The controller is designed such that the ship moves on the path with an adjustable forward speed and its total velocity is tangential to the path. The ship under consideration is not actuated in the sway axis, and the mass and damping matrices are not assumed to be diagonal. Nonlinear damping terms are also included to cover both low- and high-speed applications. The new result is facilitated by choosing an appropriate origin of the body-fixed frame, designing a suitable filter of sway velocity, several nonlinear coordinate changes, the backstepping technique, and utilizing the ship dynamic structure. Experimental results on a model ship illustrate the effectiveness of the proposed method. 相似文献
110.
Spatial and temporal structure of Tropical Pacific interannual variability in 20th century coupled simulations 总被引:1,自引:0,他引:1
Tropical Pacific interannual variability is examined in nine state-of-the-art coupled climate models, and compared with observations and ocean analyses data sets, the primary focus being on the spatial structure and spectral characteristics of El Niño-Southern Oscillation (ENSO). The spatial patterns of interannual sea surface temperature (SST) anomalies from the coupled models are characterized by maximum variations displaced from the coast of South America, and generally extending too far west with respect to observations. Thermocline variability is characterized by dominant modes that are qualitatively similar in all the models, and consistent with the “recharge oscillator” paradigm for ENSO. The meridional scale of the thermocline depth anomalies is generally narrower than observed, a result that can be related to the pattern of zonal wind stress perturbations in the central-western equatorial Pacific. The wind stress response to eastern equatorial Pacific SST anomalies in the models is narrower and displaced further west than observed. The meridional scale of the wind stress can affect the amount of warm water involved in the recharge/discharge of the equatorial thermocline, while the longitudinal location of the wind stress anomalies can influence the advection of the mean zonal temperature gradient by the anomalous zonal currents, a process that may favor the growth and longer duration of ENSO events when the wind stress perturbations are displaced eastwards. Thus, both discrepancies of the wind stress anomaly patterns in the coupled models with respect to observations (narrow meridional extent, and westward displacement along the equator) may be responsible for the ENSO timescale being shorter in the models than in observations. The examination of the leading advective processes in the SST tendency equation indicates that vertical advection of temperature anomalies tends to favor ENSO growth in all the CGCMs, but at a smaller rate than in observations. In some models it can also promote a phase transition. Longer periods tend to be associated with thermocline and advective feedbacks that are in phase with the SST anomalies, while advective tendencies that lead the SST anomalies by a quarter cycle favor ENSO transitions, thus leading to a shorter period. 相似文献