排序方式： 共有63条查询结果，搜索用时 15 毫秒
41.
A. Hernán-Caballero I. Pérez-Fournon E. Hatziminaoglou A. Afonso-Luis M. Rowan-Robinson D. Rigopoulou D. Farrah C. J. Lonsdale T. Babbedge D. Clements S. Serjeant F. Pozzi M. Vaccari F. M. Montenegro-Montes I. Valtchanov E. González-Solares S. Oliver D. Shupe C. Gruppioni B. Vila-Vilaró C. Lari F. La Franca 《Monthly notices of the Royal Astronomical Society》2009,395(3):1695-1722
42.
S. Focardi M.C. Fossi L. Lari S. Casini C. Leonzio S.K. Meidel M. Nigro 《Marine environmental research》1995,39(1-4)
The aim of this study was to determine the detoxication capacity and the sensitivity to pollutants of fish living in a pristine environment such as the Antarctic Ocean. Forty specimens of Pagothenia bernacchii collected during the Antarctic summer of 1991–1992 were divided into three groups, and were treated with 10 mg/kg of B(α)P, 50 mg/kg of PCBs and corn oil and sacrificed after 2, 4 and 10 days. The mixed function oxidase activity measured in these fish through the test of BPMO, EROD and BROD activities revealed that both B(α)P and PCBs are effective in inducing this enzyme system. Owing to the slow metabolic rate of this species, related to the low ambient temperature of its natural habitat, the highest level of induction was monitored after 10 days i.e. much later than in fish of temperate seas. 相似文献
43.
Fattahi Nafchi Rohallah Raeisi Vanani Hamid Noori Pashaee Kobra Samadi Brojeni Hosein Ostad-Ali-Askari Kaveh 《Natural Hazards》2022,110(3):1495-1505
Natural Hazards - One of the aquatic structures that are used for protect water channels against bed erosion is serial step-pool. These steps similarity of the vertical drops structure are exposed... 相似文献
44.
Sarfarazi Vahab Fattahi Shahin Asgari Kaveh Bahrami Reza Wang Xiao 《Geotechnical and Geological Engineering》2022,40(6):2881-2896
Geotechnical and Geological Engineering - This paper investigates different configuration of the room and pillar under uniaxial loading using experimental and particle flow code in two dimension... 相似文献
45.
Fabrice Hollender Cécile Cornou Aline Dechamp Kaveh Oghalaei Florence Renalier Emeline Maufroy Clément Burnouf Sylvette Thomassin Marc Wathelet Pierre-Yves Bard Vincent Boutin Clément Desbordes Isabelle Douste-Bacqué Laetitia Foundotos Cédric Guyonnet-Benaize Vincent Perron Julie Régnier Agathe Roullé Mickael Langlais Deborah Sicilia 《Bulletin of Earthquake Engineering》2018,16(6):2337-2365
Data provided by accelerometric networks are important for seismic hazard assessment. The correct use of accelerometric signals is conditioned by the station site metadata quality (i.e., soil class, VS30, velocity profiles, and other relevant information that can help to quantify site effects). In France, the permanent accelerometric network consists of about 150 stations. Thirty-three of these stations in the southern half of France have been characterized, using surface-wave-based methods that allow derivation of velocity profiles from dispersion curves of surface waves. The computation of dispersion curves and their subsequent inversion in terms of shear-wave velocity profiles has allowed estimation of VS30 values and designation of soil classes, which include the corresponding uncertainties. From a methodological point of view, this survey leads to the following recommendations: (1) perform both active (multi-analysis surface waves) and passive (ambient vibration arrays) measurements to derive dispersion curves in a broadband frequency range; (2) perform active acquisitions for both vertical (Rayleigh wave) and horizontal (Love wave) polarities. Even when the logistic contexts are sometimes difficult, the use of surface-wave-based methods is suitable for station-site characterization, even on rock sites. In comparison with previous studies that have mainly estimated VS30 indirectly, the new values here are globally lower, but the EC8-A class sites remain numerous. However, even on rock sites, high frequency amplifications may affect accelerometric records, due to the shallow relatively softer layers. 相似文献
46.
A topology optimization formulation is developed to find the stiffest structure with desirable material distribution subjected to seismic loads. Finite element models of the structures are generated and the optimality criteria method is modified using a simple penalty approach and introducing fictitious strain energy to simultaneously consider both material volume and displacement constraints. Different types of shear walls with/without opening are investigated. Additionally, the effects of shear wall-frame interaction for single and coupled shear walls are studied. Gravity and seismic loads are applied to the shear walls so that the definitions provide a practical approach for locating the critical parts of these structures. The results suggest new viewpoints for architectural and structural engineering for placement of openings. 相似文献
47.
Giacomo Lari 《Celestial Mechanics and Dynamical Astronomy》2018,130(8):50
The Galilean satellites’ dynamics has been studied extensively during the last century. In the past it was common to use analytical expansions in order to get simple models to integrate, but with the new generation of computers it became prevalent the numerical integration of very sophisticated and almost complete equations of motion. In this article we aim to describe the resonant and secular motion of the Galilean satellites through a Hamiltonian, depending on the slow angles only, obtained with an analytical expansion of the perturbing functions and an averaging operation. In order to have a model as near as possible to the actual dynamics, we added perturbations and we considered terms that in similar studies of the past were neglected, such as the terms involving the inclinations and the Sun’s perturbation. Moreover, we added the tidal dissipation into the equations, in order to investigate how well the model captures the evolution of the system. 相似文献
48.
Kaveh Sookhak Lari John L. Rayner Greg B. Davis Colin D. Johnston 《Ground Water Monitoring & Remediation》2020,40(3):21-29
It is important to estimate what light nonaqueous phase liquid (LNAPL) recovery can be practicably achieved from subsurface environments. Over the last decade, research to address this included a broad field program, laboratory measurements and experimentation, and modeling approaches. Here, we consolidate key findings from the research in the context of current literature and understanding, with a focus on a well-validated, multiphase multicomponent modeling approach to achieve estimates of reasonable endpoints for LNAPL recovery. Simple analytical models can provide approximate saturation distributions and estimates of LNAPL recoverability via transmissivity approximation, but are insufficient to predict LNAPL saturation- and composition-based recovery endpoints for various recovery technologies. This is because they cannot account for multiphase, multicomponent fate and transport and key processes such as hysteresis. Recent advances to improve estimates of the fraction of recoverable LNAPL and its transmissivity are summarized. These advances include further development and application of a well-validated model to characterize active LNAPL recovery endpoints. We present key factors that affect the determination of LNAPL recovery endpoints, and outline how recovery endpoints are affected by natural source zone depletion (NSZD—currently gaining acceptance as a LNAPL remediation option). Major factors include geo-physical characteristics of the formation, magnitude of an LNAPL release and partitioning properties of the key LNAPL constituents of concern. Based on the capabilities of the validated model, the paper also provides a basis to optimize LNAPL recovery efforts. 相似文献
49.
Hydrogeochemical investigation using multivariate analytical methods in Esfadan basin,eastern Iran 总被引：1，自引：0，他引：1
The chemical analyses of 71 water-supply wells in the Esfadan area of eastern Iran were evaluated using statistical methods to determine the hydrogeochemical processes that control groundwater quality. Groundwater in the study area is mainly saline (Na–Cl type water), and statistical analyses show that there are three subgroups of groundwater quality, whose differences reflect the influences of geology. 相似文献
50.
Kaveh Pazand Firuz Aliniya Yousef Ghanbari Hossein Hassani Nasrin Aghavali 《Arabian Journal of Geosciences》2011,5(5):1021-1029
Platinum group elements (PGE) enrichment occurs in Zn–Cu and Ni-rich ophiolities in a number of geological settings. Platinum group elements (PGE) mineralization in Pyroxenite from the Faryab ophiolities of Zagros belt in south Iran was studied. The ophiolite rocks represent blocks of Tethyan oceanic crust that were emplaced on the continental margin during the late Cretaceous period. Much of lower ophiolitic section is composed of homogeneous harzburgite, while upper sections harzburgite interlayer with dunite and pyroxenite are included. This study focused on pyroxenite that includes most of sulfide mineralization in Faryab. More than 500 samples were investigated from polished thin sections; that cover all area of Faryab. The sulfide phases include pyrrhotite, pentlandite, millerite, violarite, smythite, and heazlewoodite. The results show that in almost all the samples Os is below the 2 ppb detection limit, Platinum values vary from <5 to 91 ppb and the light PGE (Ru, Rh, and Pd) relative to the heavy PGE (Os, Ir, and Pt) are more concentrated. Calculation showed that in pyroxenites Pd–Pt is occurring with orthopyroxenite and Rh–Os is occurring in clinopyroxenite. Ni/Pd ratios in Faryab vary between 7 and 356 and Pd/Ir ratio is 0.1–27. This indicates that in Faryab area partial melt of mantle occurred. Pd/Rh ratio in Faryab is 0.1–11, and Pd/Pt varies between 0.2 and 1.5. Pd/Ir ratio in Faryab decreases and shows that PGE in Faryab occurred. 相似文献