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111.
Topographically Forced Rossby Wave Instability and the Development of Blocking in the Atmosphere 总被引:1,自引:0,他引:1
In this paper, the linear stability of disturbance superimposed on basic state Rossby wave forced by topography is investigated, and pointed out that when a certain criterion is satisfied by the basic flow and the height of topography for the subresonance, the small disturbance may be unstable. Furthermore, we also compare the evolution of the instability disturbance with the development of blocking in the Pacific, and we suggested that the topographically forced Rossby wave instability may provide a possible mechanism for the development of blocking in the Pacific. 相似文献
112.
113.
In this paper, four problems are discussed: (1) the monsoon circulation over southern Asia; (2) the seasonal variation of
the general circulation of the atmosphere; (3) the influence of the monsoon on the rainfall in southwestern China; and (4)
the source region of water vapor for the rainfall in the Changjiang valley. 相似文献
114.
本文研究了以磷酸三丁酯为固定相,大孔聚乙烯苯(X-5型)为担体的浸渍树脂、垂直型反相色谱柱,对铀分离富集的基本性能,以及铀(Ⅳ)-间硝基苯基萤光酮(m-NPF)一氨三乙酸(NTA)-吐温-80显色体系的反应条件,提出了TBP(X-5)分离,m-NPF-NTA-吐温-80光度法测定铀,经标准样品验证,结果满意。 相似文献
115.
The Daba Mountains define the southern margin of the East Qinling orogenic belt, and form the boundary of the Sichuan basin
in the north and northeast. The Daba Mountains can be divided into two structural belts by the NW-striking Chengkou fault,
namely the northern Dabashan thrust-nappe belt and the southern Dabashan foreland fold-and-thrust belt. The southern Dabashan
fold-and-thrust belt is a southwestward extruding thin-skinned thrust wedge, showing obvious belted change in deformation
style and deformation intensity along the dip direction, and can be divided further into three sub-belts, i.e. the imbricate
thrust sub-belt characterized by imbricate stepped-thrust sheets, the thrust-fold sub-belt characterized by the combination
of the equally-developed thrusts and related folds, and the detachment-fold sub-belt characterized by box folds and closed
overturned-isoclinal folds on the outcrops. Several kinds of structures have been recognized or inferred, including imbricate
thrust system, passive-roof duplex (triangle zone), fault-related folds, back-thrust system and pop-up structure. The NE-SW
compressive stress from the Qinling orogenic belt and detachment layers in the covering strata are the two most important
determinants of deformation style. After the collision between the North China block and Yangtze block at the end of the Middle
Triassic, the northward intracontinental subduction along the southern edge of the Qinling orogenic belt was initiated, which
led to the corresponding southward thrusting in the upper crust. The thrusting propagated towards the foreland through the
Jurassic and extended to the southernmost part of the southern Daba Mountains around the end of the Early Cretaceous, with
thrusting deformation to be preferentially developed along major detachment layers and progressing upwards from the Lower
Sinian through the Lower Cambrian and Silurian to Middle-Lower Triassic.
Translated from Geotectonica et Metallogenia, 2006, 30(3): 294–304 [译自: 大地构造与成矿学] 相似文献
116.
A macroscopic transport model is developed, following the Taylor shear dispersion analysis procedure, for a 2D laminar shear flow between parallel plates possessing a constant specified concentration. This idealized geometry models flow with contaminant dissolution at pore-scale in a contaminant source zone and flow in a rock fracture with dissolving walls. We upscale a macroscopic transient transport model with effective transport coefficients of mean velocity, macroscopic dispersion, and first-order mass transfer rate. To validate the macroscopic model the mean concentration, covariance, and wall concentration gradient are compared to the results of numerical simulations of the advection–diffusion equation and the Graetz solution. Results indicate that in the presence of local-scale variations and constant concentration boundaries, the upscaled mean velocity and macrodispersion coefficient differ from those of the Taylor–Aris dispersion, and the mass transfer flux described by the first-order mass transfer model is larger than the diffusive mass flux from the constant wall. In addition, the upscaled first-order mass transfer coefficient in the macroscopic model depends only on the plate gap and diffusion coefficient. Therefore, the upscaled first-order mass transfer coefficient is independent of the mean velocity and travel distance, leading to a constant pore-scale Sherwood number of 12. By contrast, the effective Sherwood number determined by the diffusive mass flux is a function of the Peclet number for small Peclet number, and approaches a constant of 10.3 for large Peclet number. 相似文献
117.
论述了在市场条件下从事隧洞工程经营工作中的信息网络建立,项目的论证与投标以及内部招标的有关问题,旨在探讨市场条件下如何提高隧洞工程的经营工作水平。 相似文献
118.
山西省雾的分析和预报 总被引:7,自引:0,他引:7
公路为山西省经济发展做出巨大的贡献。为保证公路安全畅通,本文对影响公路安全行驶的重要天气--雾的地理和时间分布进行分析,并根据雾的发生条件,提出了雾的预报思路。 相似文献
119.
经验GREEN函数法研究丽江6.0级强余震的地震动及破裂特征 总被引:1,自引:1,他引:1
利用经验Green函数方法,用1996年云南丽江地震后的ML4.7级地震合成了这次地震的最大余震Ms6.0的加速度记录,通过与实际记录在频域和时域的对比研究,分析研究了地震动特征和这次最大余震的可能破裂特征,并对经验Green函数方法进一步的改进方向进行了探讨。 相似文献
120.