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71.
A.E. Dodonov V.G. Trifonov T.P. Ivanova V.Yu. Kuznetsov F.E. Maksimov D.M. Bachmanov T.A. Sadchikova A.N. Simakova H. Minini A.-M. Al-Kafri O. Ali 《Quaternary International》2008,190(1):158
In order to provide new data on the neotectonics and geodynamic properties of western Syria, studies of marine terraces have been carried out. The most attention was paid to the lower terraces in the range of 3–5 to 30–35 m above sea level, because they have more complete distributions along the shore. The lower terraces were examined along the coastal area from Tartus to Latakia, and along the carbonate cliff on Arwad Island. Seven 230Th/U dates for these terraces are in the range of 85–130 ka, suggesting the age interval of the last interglacial (MIS 5). New dates on the lower terraces provide a basis for stratigraphical and geomorphological interpretation as well as neotectonic reconstruction. According to the geomorphological data and lithological composition of those terraces, two main uplifted blocks can be established. One coincides with the Latakia block, and another corresponds to the western margin of the Banias volcanic plateau. These blocks are divided by a subsided structure corresponding to the Nahr el Kebir graben. The amplitude of neotectonic uplifting in the Latakia and Banias blocks reaches 15–20 m for the Late Pleistocene. 相似文献
72.
Remarks on the Definition and Estimation of Friction Velocity 总被引:2,自引:1,他引:2
Rudolf O. Weber 《Boundary-Layer Meteorology》1999,93(2):197-209
One of the mainscaling parameters in similarity theory of the atmospheric boundary layer is friction velocity. Unfortunately, several definitions of friction velocity exist in the literature. Some authors use the component of the horizontal Reynolds stress vector in the direction of the mean wind vector to define friction velocity. Others define the friction velocity by means of the absolute value of the horizontal Reynolds stress vector. The two definitions coincide only if the direction of the mean wind vector is parallel to the horizontal Reynolds stress vector. In general, the second definition gives larger values for the friction velocity. Over complex terrain the situation is further complicated by the fact that the terrain following flow is not necessarily horizontal. Thus, several authors have proposed to use terrain following coordinate systems for the definition of friction velocity. By means of a large dataset of fast-response wind measurements with an ultrasonic anemometer the friction velocities resulting from the different definitions are compared. Furthermore, it is shown that friction velocity can be well estimated from horizontal wind speed, and even better from simple horizontal or vertical turbulence parameters. 相似文献
73.
Oceanology - Abstract—The paper studies carbon transformation and transfer processes in the crust and mantle. Sediments dragged into subduction zones are dewatered, broken down, and altered... 相似文献
74.
R. O. Davis 《地震工程与结构动力学》1992,21(3):253-274
Pounding of adjacent buildings is modelled by an impact oscillator subjected to harmonic excitation. Non-linear impact stiffness is represented by a Hertz-type relationship. Spectra of impact velocity are presented for a range of model parameters. These spectra are characterized by a strong peak near a period equal to one half the natural period of a similar non-impacting oscillator. Bands of response are found in which periodic multiple impacts and non-periodic or chaotic impacts occur. 相似文献
75.
The available observational data on the pollution of tributaries and areas of the Caspian Sea by petroleum hydrocarbons and
products are examined. The possible petroleum input from sources in the sea is assessed using up-to-date data of satellite
observations of sea surface pollution by oil films. The hydroecological CNPSi-model is applied to studying water pollution
processes by petroleum hydrocarbons in ten areas chosen in the Caspian Sea and the subsequent biodegradation of those pollutants.
The model calculations of the within-year dynamics of petroleum hydrocarbon concentrations use mean annual observational data
on within-year variations in water mediium characteristics (water temperature, light intensity, and transparency), as well
as the morphometric parameters of sea areas (the area, mean depth, and water volumes). The characteristics of water exchange
between the areas were evaluated using a hydrodynamic model. The model calculations were used to characterize the within-year
variations in petroleum hydrocarbon concentrations, the biomasses of petroleum-oxidizing bacteria, the characteristics of
their oxidation activity and bioproduction, and the internal fluxes of petroleum hydrocarbons (their input from various sources,
horizontal and vertical transport, and biotransformation) in different sea areas. Calculation results were used to compile
annual balances for the processes of input and consumption of petroleum hydrocarbons in the chosen and aggregated sea areas. 相似文献
76.
Ocean Dynamics - A climatological monthly mean data set for temperature and salinity in the area of the North Sea and Baltic Sea is presented. More than 3.1 million temperature observations (2.9... 相似文献
77.
Evolution of melt composition during intrusion of basalts into a silicic magma chamber 总被引:3,自引:0,他引:3
P. Yu. Plechov I. S. Fomin O. E. Mel’nik N. V. Gorokhova 《Moscow University Geology Bulletin》2008,63(4):247-257
The article describes heat exchange between basaltic and rhyolite melts accompanied by fractional crystallization of phases in a basaltic melt. A numerical model has been developed for the homogenization mechanism of magma composition during intrusion of basaltic magma batches into felsic magma chambers. The results of numerical modeling demonstrate that the time needed for cooling the basalts and their fractionation to rhyolite melts is much shorter than the time required for chemical interaction based on diffusive mechanisms. 相似文献
78.
79.
80.
A. Glabert O.S. Pokrovsky C. Reguant J. Schott A. Boudou 《Journal of Geochemical Exploration》2006,88(1-3):110
This work is devoted to the physico-chemical study of cadmium and lead interaction with diatom–water interfaces for two marine planktonic (Thalassiosira weissflogii = TW, Skeletonema costatum = SC) and two freshwater periphytic species (Achnanthidium minutissimum = AMIN, Navicula minima = NMIN) by combining adsorption measurements with surface complexation modeling. Reversible adsorption experiments were performed at 20 °C after 3 h of exposure as a function of pH, metal concentration in solution, and ionic strength. While the shape of pH-dependent adsorption edge is similar among all four diatom species, the constant-pH adsorption isotherm and maximal binding capacities differ. These observations allowed us to construct a surface complexation model for cadmium and lead binding by diatom surfaces that postulates the constant capacitance of the electric double layer and considers Cd and Pb complexation with mainly carboxylic and, partially, silanol groups. Parameters of this model are in agreement with previous acid–base titration results and allow quantitative reproduction of all adsorption experiments. 相似文献