排序方式： 共有81条查询结果，搜索用时 15 毫秒
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Ashraf Samaneh AghaKouchak Amir Nazemi Ali Mirchi Ali Sadegh Mojtaba Moftakhari Hamed R. Hassanzadeh Elmira Miao Chi-Yuan Madani Kaveh Mousavi Baygi Mohammad Anjileli Hassan Arab Davood Reza Norouzi Hamid Mazdiyasni Omid Azarderakhsh Marzi Alborzi Aneseh Tourian Mohammad J. Mehran Ali Farahmand Alireza Mallakpour Iman 《Climatic change》2019,152(3-4):379-391
Climatic Change - By combining long-term ground-based data on water withdrawal with climate model projections, this study quantifies the compounding effects of human activities and climate change... 相似文献
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A multiple rocking wall-frame(MRWF)system,in which the wall panels are directly connected to the adjacent beams and foundation is presented herein.In the MRWF s... 相似文献
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Victor Salinas Arantza Ugalde Ahmad Kamayestani Mehrab Jokar Mojtaba Moradi Gharibvand Antonio Villaseñor Ghasem Heidari 《Geophysical Prospecting》2019,67(6):1652-1663
From August 2016 to July 2017, a passive seismic survey was conducted in South Western Iran as a part of a pilot project aimed to improve the imaging in geologically complex areas. Passive seismic methods have shown to be a useful tool to infer the physical properties of the underground geological structures where traditional hydrocarbon exploration methods are challenging. For this purpose, a dense passive seismic network consisting of 119 three-component borehole seismic stations was deployed over an area of 400 km2 around the city of Dehdasht. This paper focuses on the details of the network design, which was devoted to high-resolution seismological applications, including local earthquake tomography and seismic attenuation imaging. In this regard, we describe the instrument types and the station installation procedures used to obtain high-quality data that were used to retrieve three-dimensional models of P- and S-wave velocity and P-wave attenuation in the area using tomographic inversion techniques. We also assess the network performance in terms of the seismic ambient noise levels recorded at each station site, and we revise the horizontal orientation of the sensors using surface waves from teleseismic earthquakes. 相似文献
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The cross section for a neutron-deuteron(nd) radiative capture is calculated using the pionless effective field theory including isospin symmetry breaking(ISB) corrections up to higher order.The triton is studied as a three-body bound state and one has to take into account various ISB effects,relativistic corrections and external electromagnetic currents.The isospin violation in nd radiative capture is improved compared to the one at NLO and N2LO.The cross section is determined to beσtot= [0.505 ± 0.003] mb up to N2LO.A satisfactory agreement between theory and experiment for the calculated cross section has been found by insertion of three-body forces and ISB effects. 相似文献
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R. F. Motlagh J. Valiallahi M. Baghdadi 《International Journal of Environmental Science and Technology》2018,15(7):1573-1580
Death Valley located in the Zagros Mountains, Khuzestan Province, Iran, along the Bangeston Fault line is a unique landscape. Water flows from a hot headstream through a colorful bed into the valley for about 2 km down-run and disappears through the alluvial deposits. This spring and its surrounding area were found to be deadly for both animals and humans. In the last decade, it has been reported that five persons and many animals have died. The reason for the toxicity of this water has not yet been specified. Attempts have been made to find out the secret behind death. The purpose of this paper is to study the Death Valley, which is located in the south of Iran (Tashan), as well as the lethal agent and other index mineral compounds in its water. Air analysis was performed near the headstream to find more about the fatal gas in the area. The results showed that the concentration of hydrogen sulfide was as high as 400 ppm near the spring during hot season, which could lead to pulmonary edema and death. Water in the area contains a high concentration of sulfide (1780 mg/L), which is a characteristic of thermal or hot spring waters. This gas is available along the stream and also far from the spring. The amount of spring water is high enough to be exploited for remedial purposes. 相似文献
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Mohammad Vaghefi Mohammad Javad Tabib Nazhad Motlagh Seyyed Shaker Hashemi Sahar Moradi 《Arabian Journal of Geosciences》2018,11(5):102
In this study, scouring around piers perpendicular to flow (PPF) and piers toward the flow (PTF) under clear-water condition was examined by placing a set of triad cylindrical piers with a 5-cm diameter and a 15-cm center to center distance at the positions of 60, 90, and 120° of the bend at a constant flow rate of 70 l per second. Natural sand of uniform grain size and average diameter of 1 mm with a uniformity coefficient of 1.3 was used as bed material of the flume. According to the results of this study, the maximum scouring depth occurred in the PPF test situated at the position of 90° of the bend. In such a position, the maximum depth of scouring hole was equal to 1.1 times the depth of the flow at the beginning of the bend. Also, where the piers were positioned in PTF and PPF modes in a 60° angle, the maximum area of scouring hole was observed around piers and sediment piles at the downstream side of the piers. The maximum height of sedimentation occurred in the PPF test situated at the 90° position of the bend. Such a stack was as high as 0.7 times the flow depth at the beginning of the bend and was observed at the 156° position of the bend, at a 20% distance of the flume width from the inner bank. Further results as well as discussion and analysis are among other points presented in the article. 相似文献
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Mojtaba Babaei Mirsattar Meshinchi-Asl Hossein Zomorrodian 《Arabian Journal of Geosciences》2014,7(6):2363-2366
In this paper, we have developed a least-squares minimization method to estimate the depth of a buried conducting sphere using electromagnetic induction (EMI) data. This approach is basically based on the solving a set of algebraic linear equations to estimate the depth of sphere embedded in an insulating media. In electromagnetic induction method, the transmitter coil produces the incident magnetic and electric fields that obey the Maxwell’s equations. In the receiver coil, the received response is created in two modes—eddy-current mode (V ec) derived from the perfectly conductor placed in the shallow depth and another mode called current-channeling response (V cc) which depends on the conductivity of the medium. As expected, these responses differ depending on the direction of the incident field related to the receiver coil’s axis. In our case, the transmitter coil’s axis is parallel to the ground surface, and only the eddy-current response is measured in the receiver coil. The validity of this new method is demonstrated through studying and analyzing synthetic EMI anomalies, using simulated data generated from a known model with different random error components and a known statistical distribution. 相似文献
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In this research, the hydraulic conductivity changes in uniformly graded sands, due to injection pressure increase, were experimentally evaluated using a cell-type radial model. Conducted tests, simulating variation of media permeability at different depths along a recharge well, were monitoring variations of the samples’ hydraulic conductivity at predetermined three different overburden pressures. The startup low pressure inflow was afterward altered by increasing the injection pressure up to the point at which hydraulic conductivity started to change at each run; we called it the threshold injection pressure. The corresponding hydraulic conductivity at such pressure was measured. As the increased permeability was a function of distance to the simulated recharge, it was deemed too beneficial to develop an equation to enable predicting this new hydraulic conductivity at different distances. Findings indicate that in uniformly graded sands under overburden pressure up to 68.64 kPa, the hydraulic conductivity in the threshold injection pressure—compared to its primary amount up to 45 cm from borehole wall—show a remarkable growth. However, this growth rate for greater distances up to 60 cm is negligible. Furthermore, in the threshold injection pressure, the hydraulic conductivity seems not to be time dependent. But, in constant injection pressures above the threshold injection pressure, the hydraulic conductivity shows some sort of time dependency. 相似文献
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We present CCD B and V light curves,obtained in the year 2006,and a photometric solution of the low-mass ratio contact binary ASAS 021209+2708.3. With our data we were able to determine six new times of minimum light and refine the orbital period of the system to 0.3181963 days.The light curves are analyzed using the 2003 version of the Wilson-Devinney program and the analysis was performed with and without adding a spot on the surface of one star because the light curves appear to exhibit a typical O’Conne... 相似文献