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11.
K. Karami M. Jamil M. Roos S. Ghaffari A. Abdolmaleki 《Astrophysics and Space Science》2012,340(1):175-184
We study the entropy-corrected version of the new agegraphic dark energy (NADE) model and dark matter in a spatially non-flat Universe and in the framework of Hořava-Lifshitz cosmology. For the two cases containing noninteracting and interacting entropy-corrected NADE (ECNADE) models, we derive the exact differential equation that determines the evolution of the ECNADE density parameter. Also the deceleration parameter is obtained. Furthermore, using a parametrization of the equation of state parameter of the ECNADE model as ω Λ(z)=ω 0+ω 1 z, we obtain both ω 0 and ω 1. We find that in the presence of interaction, the equation of state parameter ω 0 of this model can cross the phantom divide line which is compatible with the observation. 相似文献
12.
Na Liu Thomas N. Buckley Xinguang He Xinping Zhang Cicheng Zhang Zidong Luo Hailong Wang Nasrin Sterling Huade Guan 《水文研究》2019,33(12):1670-1685
Plant transpiration depends on environmental conditions, and soil water availability is its primary control under water deficit conditions. In this study, we improve a simplified process‐based model (hereafter “BTA”) by including soil water potential (ψsoil) to explicitly represent the dependence of plant transpiration on root‐zone moisture conditions. The improved model is denoted as the BTA‐ψ model. We assessed the performance of the BTA and BTA‐ψ models in a subtropical monsoon climate and a Mediterranean climate with different levels of water stress. The BTA model performed reasonably in estimating daily and hourly transpiration under sufficient water conditions, but it failed during dry periods. Overall, the BTA‐ψ model provided a significant improvement for estimating transpiration under a wide range of soil moisture conditions. Although both models could estimate transpiration (sap flow) at night, BTA‐ψ was superior to BTA in this regard. Species differences in the calibrated parameters of both models were consistent with leaf‐level photosynthetic measurements on each species, as expected given the physiological basis of these parameters. With a simplified representation of physiological regulation and reasonable performance across a range of soil moisture conditions, the BTA‐ψ model provides a useful alternative to purely empirical models for modelling transpiration. 相似文献
13.
Kerman province, located in the south eastern Iran, is dominated with clays which can be used in different projects. The liner system within a landfill is constructed to control leachate migration and can be constructed by low permeable natural soils or plastic lining materials, environmentally however, natural materials is preferred that usually need to be amended in order to meet requirements recommended by environmental agencies. This research examines the possibility of using the Kerman collapsible clay as a liner layer material. A set of laboratory test was conducted on pure soil samples and additive treated samples. The moderate collapse potential of the used soil is decreased with wet compaction and under the effect of additive-soil reactions. Laboratory investigations showed that lime and bentonite treatment improved the hydraulic conductivity. The results revealed hydraulic conductivities on the order of 10?8 m/s. The obtained values met the 1.0E?07 m/s criterion required by Iranian standards. Unconfined compression tests were also performed on pure soil and additive amended samples. The unconfined compression strength values demonstrated gradual decreases with the addition of bentonite and considerable increases with adding lime such that with adding 1% lime the unconfined compression strength increased by 75%. This study verified that the Kerman collapsing clay can be used as a liner material using lime and bentonite as additives. 相似文献
14.
Vahid Nourani Biswajeet Pradhan Hamid Ghaffari Seyed Saber Sharifi 《Natural Hazards》2014,71(1):523-547
Without a doubt, landslide is one of the most disastrous natural hazards and landslide susceptibility maps (LSMs) in regional scale are the useful guide to future development planning. Therefore, the importance of generating LSMs through different methods is popular in the international literature. The goal of this study was to evaluate the susceptibility of the occurrence of landslides in Zonouz Plain, located in North-West of Iran. For this purpose, a landslide inventory map was constructed using field survey, air photo/satellite image interpretation, and literature search for historical landslide records. Then, seven landslide-conditioning factors such as lithology, slope, aspect, elevation, land cover, distance to stream, and distance to road were utilized for generation LSMs by various models: frequency ratio (FR), logistic regression (LR), artificial neural network (ANN), and genetic programming (GP) methods in geographic information system (GIS). Finally, total four LSMs were obtained by using these four methods. For verification, the results of LSM analyses were confirmed using the landslide inventory map containing 190 active landslide zones. The validation process showed that the prediction accuracy of LSMs, produced by the FR, LR, ANN, and GP, was 87.57, 89.42, 92.37, and 93.27 %, respectively. The obtained results indicated that the use of GP for generating LSMs provides more accurate prediction in comparison with FR, LR, and ANN. Furthermore; GP model is superior to the ANN model because it can present an explicit formulation instead of weights and biases matrices. 相似文献
15.
The projection of an axially symmetric satellite's orbit on a plane perpendicular to the rotation axis (z=const.) is given by the second-order differential equation. $$\frac{{y''}}{{1 + y'^2 }} = \bar \Psi _y - y'\bar \Psi _{x,}$$ where the prime denotes the derivative with respect tox and \(\bar \Psi (x,y)\) is a known function. Two integrability cases have been investigated and it has been shown that for these two cases the integration can be carried out either by quadratures or reduced to a first-order differential equation. Analytical and physical properties are expressed, and it is shown that the equation can be derived from the calssical plane eikonal equation of geometric optics. 相似文献
16.
Kamal SIAHCHESHM Nasrin KHAJEMOHAMMADLO Ali Asghar CALAGARI Ali ABEDINI 《《地质学报》英文版》2021,95(3):846-859
The Aghbolaq skarn deposit is located in the Urumieh-Golpayegan plutonic belt,NW Iran.The garnetite skarn(stage I) has been intensely cross-cut by the magnetite-garnet skarn (stage II) which were,in turn,cut and offset by the orehosting quartz veins/veinlets (stage III).The predominance of andradite (Adr_(82.5–89.1)) and its high Fe~(3+)/Al ratio (up to 1685)apparently supports the high f O_2,salinity and prevalence of magmatic/hydrothermal fluids involved,rather than meteoric waters,during the magnetite-garnet skarn formation.Two major groups of fluid inclusions,namely aqueous (LV,LVS) and aqueous–carbonic (LV_C,LL_CV_C),were recognized in garnet and quartz veins that,especially in growth zones and along intra-granular trails,better display fluid inclusion assemblages (FIAs) than those in clusters.The prograde magnetite-garnet skarn was formed by the metasomatic fluid at relatively high T_h (209–374℃),under a lithostatic pressure of～200 bars.The retrograde mineralized quartz veins were formed at temperatures ranging from 124℃to 256℃,by dilute and less saline(2.57–11.93 wt%Na Cl eq.) hydrothermal fluids under a hydrostatic pressure of～80 bars.The fluid evolution of the Aghbolaq skarn began with an earlier simple cooling of metasomatic fluid during the prograde stage,followed by the later influx of low salinity meteoric fluids during the retrograde stage. 相似文献
17.
Rezaie-Atagholipour M Riyahi-Bakhtiari A Sajjadi M Yap CK Ghaffari S Ebrahimi-Sirizi Z Ghezellou P 《Marine pollution bulletin》2012,64(2):416-421
This study is the first detailed ecotoxicological study of the annulated sea snake, Hydrophis cyanocinctus. Concentrations of lead, cadmium, nickel and vanadium were evaluated in muscle, liver, kidney, skin and blood of the annulated sea snake (H. cyanocinctus) and in the whole bodies of its main prey species (Periophthalmus waltoni and Boleophthalmus dussumieri) in the Hara Protected Area, the Persian Gulf. The mean concentrations of lead and vanadium were highest in the kidney, which identified the kidney as a target organ for metals in sea snakes as it is in other reptilian groups. Mean concentrations of cadmium and nickel were highest in the liver and skin, respectively. Mean cadmium concentrations were significantly higher in the liver compared to prey species, which indicated that prey items may be a source of cadmium for the annulated sea snake in the study area. Data presented here may be considered as a baseline for further ecotoxicological studies in sea snakes. 相似文献
18.
Natural Hazards - “Streets have been turned into rivers”; this is a news headline which we have been hearing more often recently and refers to the floodwaters flowing into cities.... 相似文献
19.
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
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