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 ...

plagiarism in esl/efl learning contexts has been established as a dynamic and multi-layered phenomenon and has become a topic engaging many researchers in a heated debate in recent years. comparisons of student-generated texts with their source texts have shown that students rely on source texts in their writings and copying is a major strategy used by both l1 and l2 writers. in our country a...

supervisors play an undeniable role in training teachers, before starting their professional experience by preparing them, at the initial years of their teaching by checking their work within the proper framework, and later on during their teaching by assessing their progress. but surprisingly, exploring their attributes, professional demands, and qualifications has remained a neglected theme i...

in this project, some new polyaspartimides, (pas)s, have been synthesized form michael addition reaction between new synthetic bismaleimide (bmi) and some aromatic diamines. a characteristic property of this polyaspartimides is a pendent carboxylic group, which introduced to these polymers from new bismaleimide. bismaleimides (bmi) is one of the interesting compounds, which can be self-polymeri...

in this thesis, a new optically active poly(amide-imide) (pai) was synthesized by the indirect polycondensation reaction of the l-phenylalanine based diacid chloride and 4,4?-diaminodiphenylether in the presence of triethylamine in n-methyl-2-pyrrolidone. the formation of pai was confirmed by ftir, 1h nmr and elemental analysis. in next step, the surface of titanium dioxide (tio2) nanoparticles...

there has been a gradual shift of focus from the study of rule systems, which have increasingly been regarded as impoverished, … to the study of systems of principles, which appear to occupy a much more central position in determining the character and variety of possible human languages. there is a set of absolute universals, notions and principles existing in ug which do not vary from one ...

abstract ion selective electrodes (ises) are electrochemical sensors that respond selectivity to the activity of ionic species. an ion-selective electrode is an electrochemical device that uses a thin selective membrane or film as the recognition element, and is an electrochemical half-cell equivalent to other half-cells of the zeroth (inert metal in a redox electrolyte). in common methods o...

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...

abstract: the present thesis includes ; one preface and 11speeches , that each speech considered in different researches . the prefact part , studied grammer back ground , the first speech considered a brief description about grammatical credits . the second speech considered the different typs of sentences , from structure and meaning points of view . the third speech considered the verb es...

this work is presented in five parts. in the first part preparation of the starting complex [pt(c^n)cl(dmso)], 1, in which c^n = n(1),c(2?)-chelated, deprotonated 2-phenylpyridine, and dmso = dimethylsulfoxide, and its reaction with 1 equiv of the biphosphine ligands bis(diphenylphosphino)amine, dppa, or bis(diphenylphosphino)methane, dppm, to give the complex [pt(c^n)cl(dppa)], 2, or [pt(c^n)c...