this thesis basically deals with the well-known notion of the bear-invariant of groups, which is the generalization of the schur multiplier of groups. in chapter two, section 2.1, we present an explicit formula for the bear-invariant of a direct product of cyclic groups with respect to nc, c>1. also in section 2.2, we caculate the baer-invatiant of a nilpotent product of cyclic groups wuth resp...

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...

the purpose of this study is to investigate the relationships between teachers’ immediacy behaviors and iranian students’ willingness to talk in english classes. analysis of the results from willingness to talk scale represents a relatively high level of willingness to talk in english classrooms among iranian language learners. the total mean score of students’ willingness to talk was 66.3 ou...

in this thesis, phosphorus ylides [phbppy], [no2bppy] and [brbppy] have been synthesized through the formation of phosphonium salt and dihydrogenation, followed by the reaction of pd(oac)2 and the orthopalladated dinuclear complexes [pd(?-cl)(phbppy)]2, [pd(?-cl)(no2bppy)]2 and [pd(?-cl)(brbppy)]2 have been produced. the reaction of dinuclear complexes and bidentate ligands [l = bipy (2,2-bipyr...

one of the most important number sequences in mathematics is fibonacci sequence. fibonacci sequence except for mathematics is applied to other branches of science such as physics and arts. in fact, between anesthetics and this sequence there exists a wonderful relation. fibonacci sequence has an importance characteristic which is the golden number. in this thesis, the golden number is observed ...

چکیده مورچه‏ها با حمایت از شپشک‏ها در مقابل دشمنان طبیعی، می‏توانند برنامه‏های کنترل بیولوژیک آن‏ها را مختل ‏نمایند. طی سال‏های 1389 و 1390 با نمونه‏برداری از باغات مرکبات شهرستان‏های ساری و بهشهر، فون و فراوانی نسبی مورچه‏هایِ همراه با شپشک‏ها مورد مطالعه قرار گرفت. همچنین، تاثیر تراکم‏های مختلف کاست کارگر گونه‏ی santschi lasius turcicus بر میزان تغذیه و فراسنجه‏های واکنش تابعی حشرات ماده و لا...