نتایج جستجو برای: are surface density variations
تعداد نتایج: 5726623 فیلتر نتایج به سال:
the methods which are used to analyze microstrip antennas, are divited into three categories: empirical methods, semi-empirical methods and full-wave analysis. empirical and semi-empirical methods are generally based on some fundamental simplifying assumptions about quality of surface current distribution and substrate thickness. thses simplificatioms cause low accuracy in field evaluation. ful...
among the low–dimensional allotropes of carbon, nanotubes and graphene have attracted very much attention from nano–science and nanotechnology specialists. they have been proposed as building blocks in nanometer device engineering. however, these structures are not defect–free. in this thesis, we focused on defective carbon nanotubes and graphene, and studied the effect of couple of very common...
in this thesis protic and aprotic ammonium-based ionic liquids were synthesized and their surface tensions were measured in the range of 298-373k. the protics are alkyl ammonium-based ils with the carboxylate (formate, acetate, propionate) anion and aprotics are quaternary ammonium-based ils with bis(trifluoromethylsulfonyl)imide anion. capillary rise method was used for surface tension measure...
in this thesis, structural, electronical, and optical properties of inverse pervskite(ca3pbo) in cubic phase have been investigated.the calculation have been done based on density functional theory and according to generalized gradiant approximate (gga) as correlating potential. in order to calculate the configurations, implementing in the wien2k code have been used from 2013 version. first of ...
in this investigation the effect of external field on the electron density of nanostructures of cds, cdse, cdte, gaas and polymeric structure of three, four, five and six units of cds as a kind of nanosolar cells has been studied theoretically. as modeling this system in nanodimension, molecular structures has used. specific properties of molecular structures permit us to consider different sym...
background: st. john’s wort (hypericum perforatum l.) is an important medicinal plant that has been widely used for its antidepressant properties. objective: in this study morphological characteristics variation of populations of h. perforatum were investigated. methods: in this study, different morphological characteristics of 25 h. perforatum populations in iran’s natural habitats were evalua...
Background: St. John’s wort (Hypericum perforatum L.) is an important medicinal plant that has been widely used for its antidepressant properties. Objective: In this study morphological characteristics variation of populations of H. perforatum were investigated. Methods: In this study, different morphological characteristics of 25 H. perforatum populations in Iran’s natural habitats were eva...
the present paper studies the possibility of propagation of torsional surface waves in an inhomogeneous anisotropic layer lying between two heterogeneous half-spaces (upper and lower half-space). both the half-spaces are assumed to be under compressive initial stress. the study reveals that under the assumed conditions, a torsional surface wave propagates in the medium. the dispersion relation ...
the grace mission has provided scientific community time-variable gravity field solutions with high precision and on a global scale. the grace mission was launched on march 2003. this mission consists of two satellites that pursue each other in their orbit. distance between two satellites in orbit is measured continuously to an accuracy of better than 1 micron using kbr system placed in satelli...
Caspian Sea with an average depth of 27m is the largest enclosed water body in the world. Despite its enormity and valuable biotic and economic resources, investigations on the biota and seawater properties are mosaic at best. In previous studies, the monitoring of the chlorophyll-a concentrations in the Southern Caspian Sea was organized based on satellite data sets however, vertical dis...
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