共查询到20条相似文献，搜索用时 250 毫秒
1.
Nachasova I. E. Pilipenko O. V. Tsetlin Yu. B. 《Izvestiya Physics of the Solid Earth》2022,58(2):203-215
Izvestiya, Physics of the Solid Earth - Abstract—Archaeomagnetic studies have been carried out for the ceramics from cultural deposits of multilayered archaeological monuments Sakhtysh I and... 相似文献
2.
3.
The natural abundance of 15N (δ15N) has been widely used to detect anthropogenically derived N loads in environmental impact studies. The present study involved retrospective analysis of subsamples of Fucus vesiculosus L. collected during a period of three years (2008–2010) from two sites: a control site, within a coastal reference area, and an area affected by the effluents of a marine land-based fish farm. The isotopic signal in different subsamples of the macroalgae thalli (tissue that has grown during the same period) varied depending on the age of the tissue. Moreover, the isotopic signal decreased significantly with the age of the frond to within a certain range. The δ15N of F. vesiculosus is temporally unstable; therefore, measurement of the δ15N of macroalgal tissues does not allow reliable retrospective biomonitoring of environmental pollution. Further knowledge about the growth and other biological aspects of this species is required. 相似文献
4.
《国际泥沙研究》2007,22(4):327-328
No. 1, 2007 Prediction of the Grain Size of Suspended Sediment: Implications for Calculating Suspended Sediment Concentrations Using Single Frequency Acoustic Backscatter R. A. KUHNLE, D. G. WREN, and J. P. CHAMBERS (pp. 1-15) Numerical Modeling of Heavy Metal Pollutant Transport-Transformation in Fluvial Rivers:A Review S. L. HUANG, Z. H. WAN, and P. SMITH (pp. 16-26) Sediment Transport Capacity-An Improved Bagnold Formula Shu-Qing YANG, Sung-Cheol KOH, In-So… 相似文献
5.
P.ecent progress in studies of experimental rock mechanics and tectonophysics in China 总被引：1，自引：0，他引：1
This paper reviews the recent progress in the studies of experimental rock mechanics and tectonophysics concern-ing seismology and physics of the Earth‘s interior in China. The progress is presented in the following aspects: a) A lot of results of experiment and numerical simulation enrich our knowledge of the brittle fracturing process under the condition with heterogeneity in material and structure; b) Some new results on frictional behavior of non-homogeneous faults reveal the complexity of faulting behavior; c) Some new results on the brittle-plastic tran-sition and plastic flow are obtained; especially the important progress is obtained on theological properties of rocks in the lower crust and the upper mantle; d) A lot of experimental results are obtained on rock physics at high tem-perature and pressure and have been used in study of material composition and state. These results provide useful information for understanding the physical properties and deformation mechanisms of material of the Earth‘s inte-rior and earthquake physics. 相似文献
6.
It is well known that the results of determining earthquake parameters depend to a large extent on data processing algorithms and velocity models of the seismic wave propagation medium used in solving hypocenter problems. In 1992, V.Yu. Burmin developed a hypocentric algorithm that minimizes the functional of distances between the points corresponding to the theoretical and observed travel times of seismic waves from an earthquake source to recording stations. The determination of the coordinates of earthquake hypocenters in this case is much more stable than for the commonly used minimization of the functional of discrepancies in the seismic wave arrival times at a station. Using this algorithm and the refined velocity model of the medium, V.Yu. Burmin and L.A. Shumlyanskaya reinterpreted the earthquake parameters for the Crimea–Black Sea region. The most important result of this reinterpretation was the conclusion about the occurrence of deep earthquakes with a source depth of more than 60 km in the region. This result contradicts the conventional beliefs about the seismicity of the region and therefore aroused strong criticism from experts directly involved in compiling the existing catalogs of regional earthquakes. These comments and criticisms are presented by V.E. Kulchitsky with coauthors in a work published in this issue of the journal. In the present paper, we analyze the comments in detail and respond. In particular, we show that the previously used methods of seismic data processing made it highly unlikely by default that deep earthquakes would appear in the results. As an example, we refer to the use of travel-time curves for depths down to 35 km. It is clear that deep earthquakes could not have been found with this approach. 相似文献
7.
8.
9.
10.
11.
Textual research of Wudu earthquake in 186 B.C. in Gansu Province, China and discussion on its causative structure 总被引：2，自引：0，他引：2
On the basis of the textual research on the historical earthquake data and the field investigation of Wudu earth- quake occurred in 186 B.C., we suggest that the earthquake parameters drawn from the present earthquake catalogs are not definite and amendments should be made. The heavily-damaged area of this earthquake should be located between Jugan township of Wudu County and Pingding township of Zhouqu County. Its epicenter should be in the vicinity of Lianghekou in Wudu County with a magnitude of about 7~7 41 and an intensity of about IX~X. The major axis direction of the heavily-damaged area should be in the WNW direction that is approximately consistent with the strike of the middle-east segment of Diebu-Bailongjiang active fault zone, and the origin time should match up to that of the latest paleoearthquake event [before (83±46) B.C.] obtained by the trench investigation. Certain seismic rupture evidences are still preserved on this fault segment. Therefore, we propose on the basis of comprehensive analysis that the causative structure of the M 7~7 4/1 Wudu earthquake in 186 B.C. should be in the middle-east segment of Diebu-Bailongjiang active fault zone. 相似文献
12.
V. V. Shcherbakova G. V. Zhidkov V. P. Shcherbakov 《Izvestiya Physics of the Solid Earth》2008,44(10):816-821
A large volume of data on the paleointensity H an obtained by A.S. Bol’shakov and G.M. Solodovnikov is ignored in modern reconstructions because the authors did not indicate whether they used the check-point procedure for the detection of chemical alterations in rocks associated with determination of H an. The paper presents new values of H an determined by the Thellier-Coe method with the use of the checkpoint procedure from samples of the Armenian collection of Cretaceous rocks used in published studies of Bol’shakov and Solodovnikov. The new results are close to the published ones and point to a small value of the geomagnetic field in the Cretaceous, thereby corroborating Bol’shakov-Solodovnikov’s hypothesis on a low paleofield in the Mesozoic. Our study of samples of the collection studied confirms the reliability of Bol’shakov-Solodovnikov’s determinations of H an. 相似文献
13.
14.
In the past two decades numerous studies were made to develop and improve the theory and practical computation techniques of synthesizing theoretical seismograms for the model of multi-layered half-space. Today, synthesizing theoretical seismograms in multi-layered half-space is an important tool for understanding the structure of the Earth's interior as well as the seismic source process from well-recorded seismograms data. As part of a review of the state-of-the-art, in this article I shall present a systematic and self-contained theory of elastic waves in multi-layered half-space media based on the developments in the past two decades. 相似文献
15.
16.
Charles W. CARLSTON 《水文科学杂志》2013,58(3):62-84
ABSTRACT Sir Charles Cotton (1964) has pointed out that in an earlier paper (Carlston, 1963) which related drainage density to hydrology, there was insufficient emphasis on the role of climate in its effect on drainage density. Re-examination of the relation of drainage density to base flow in the 15 basins originally described has revealed additional evidence that base flow is affected by precipitation or recharge (a climatic variable), while varying inversely with drainage density. Within the climatic region studied in the earlier paper (the Humid Subtropical Climate of the eastern U. S.), no evidence could be found that amount or intensity of rainfall affected the intensity of flood runoff or the scale of drainage density. In comparison with other climates, however, such as the Marine West Coast Climate, it is possible that the less intense precipitation of a marine climate may result in lower runoff intensities and lower drainage densities, however the lower mean temperatures of such climates may develop soils of generally higher infiltration capacity which would produce lower drainage densities. A progressive increase in aridity results in a decrease in soil and vegetal cover which greatly magnifies the range of drainage densities characteristic of semi-arid regions. In such regions, where the land sur-face has a good infiltration capacity rainfall sinks readily into the dry soil (although recharge to ground water may be negligible), and runoff is virtually zero, as is drainage density, Impermeable terranes devoid of vegetal and soil cover reject the rain, runoff is briefly total and drainage density may be greatly magnified, as in the South Dakota Badlands, where drainage density runs into the hundreds. Arid or Desert Climates should produce erosional landforms with generally high drainage densities, though not reaching the magnitudes of drainage density found in the semi-arid badlands where rainfall intensities are much higher. 相似文献
17.
L. Olayinka ASSEEZ 《水文科学杂志》2013,58(3):61-62
Abstract When a river flows into a reservoir, the solid materials it carries sink to the bottom thus reducing the potential reservoir capacity. The suspended load of eight major western rivers flowing into Kainji Lake was determined as a part of the investigation of the suspended sediment of the reservoir. The sediment content in each sample was determined in parts per million. On the whole the results of this study is in agreement with the previous conclusion that the sediment load of the Niger was low. A range of 29–221 ppm was observed within the reservoir whereas the concentration in the inflowing rivers varied from 122–953 ppm. It was however not possible to determine the total sediment load because discharge data were lacking. The data presented herein confirm the earlier conclusion that the rate of silting is slow but indicate that locally high rate of sediment supply should give cause for anxiety regarding the possible growth of deltas as the months of these rivers. The full potential of this study is difficult to assess at this stage but it has revealed a number of problem areas worth looking into in future years. A number of future studies believed to be capable of giving the necessary data for operation and management of the reservoir are recommended. 相似文献
18.
19.
J. C. SCHÖNFELD 《水文科学杂志》2013,58(1):11-22
Abstract The intrusion of seawater in a tidal river is treated as a diffusion problem, characterized by a coefficient of longitudinal diffusivity. In order to analyse the longitudinal diffusivity, a mathematical model is set up, consisting of two bodies of water, either one besides the other or one on top of the other. The two bodies are assumed to move relatively to each other, as a secondary effect of the tidal flow. It is moreover assumed that there is turbulent exchange of salt between the bodies. It is demonstrated that the diffusion of salt into the river is greatest for an optimum value of the coefficient of exchange between the two bodies. Exchange weaker or stronger than this optimum both diminish the salt intrusion. The theory is applied to the Rotterdam Waterway, for which estimates of the exchange are made. Estimation of the reduction of the turbulence by stratification and hence of the vertical exchange, shows that the observed strong intrusion is explainable. Intensified vertical mixing, for instance as provoked by compressed air, need not always result in less intrusion, and hence should be considered carefully. 相似文献
20.
ANDRÉ RENAUD 《水文科学杂志》2013,58(2):109-116
Abstract The authors give data of water infiltrations in horizontal and vertical columns, and in a two dimensional model. The soils are two mixtures of sand and loam, and a natural sandy loam. The characteristics of these soils are given in the article. As a conclusion, the two dimensional problem can be approached by a linear combination of data in horizontal and vertical columns. 相似文献