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...

abstract in first part of this project, the use of a new and biguanid-like catalyst supported on silica as a recyclable catalyst provides a new route for the synthesis of a variety of arylalkylidene rhodanine derivatives through knoevenagle reaction in at present of solvent at room temperature. rhodanine derivatives and especially arylalkylidene rhodanines have proven to be attractive compound...

according to coates’s (2004, as cited in zhang, 2010) definition of "conversational dominance" (p.111), it refers to the phenomenon of a speaker dominating others in interaction. specifically, it means how a speaker makes use of certain strategies to get the floor and maintain the floor. thus, the amount of talk is the main measurement for the dominance of the conversation. whether a speaker do...

دسته ای از ترکیبات شیمیائی که مخصوصا با گسترش زندگانی جدید (ماشینی)اهمیت فرآینده ای پیدامی کنند، افزودنیهای مختلف غذائی میباشند که در صنایع مربوطه بکار گرفته می شوند بکارگیری بخشی از این موا تحت عنوان طعم دهنده ها بمنظور تامین طعم و مزه طبیعی درفرآورده های صنعتی تقریبا اجتناب ناپذیر گشته و همگام با توسعه تولیدات روبه توسعه می رود. یک شناخت سیستماتیک و جامع از خواص و آثار اینگونه مواد طبیعتا مست...

attempts have been made to study the thermodynamic behavior of 1,3 butadiene purification columns with the aim of retrofitting those columns to more energy efficient separation schemes. 1,3 butadiene is purified in two columns in series through being separated from methyl acetylene and 1,2 butadiene in the first and second column respectively. comparisons have been made among different therm...

abstract the current study sets out 1) to investigate the strategic needs of iranian efl learners in reading literary and non-literary texts; 2) to shed some light on the differences between reading literary and non-literary texts; and 3) to specify the differences in the interaction of participants with texts while reading two literary subgenres ( i.e., short story and literary essays). to ...

abstract the cr(iii) and zn(ii) complexes with 2-((9,10-dihydro-1-hydroxy-9,10-dioxaanthracen-4-yloxy)carbonyl)benzoic acid as ligand have been prepared by reacting cr(no3) and zn(no3)2 and ligand in cloroform. the cr and zn complexes with 2-((9,10-dihydro-1-hydroxy-9,10-dioxaanthracen-4-yloxy)carbonyl) were also prepared in chloroform and aceton solutions. the uv-visible and ft-ir spectra of...

most specialists in the field of foreign language teachingconsiderreading skill as an interactive process between the reader’s prior knowledge and the text.accordingly, the activation of prior knowledge for an effective comprehension is very important. it is generally agreed that the pre-reading phase is the stage where this type of interaction and activation may be enhanced throughcertain stra...

the present study was an attempt to conduct a contrastive analysis between general english (ge) and english for specific purposes (esp) texts in terms of cohesion and cohesive devices. to this end, thirty texts from different esp and ge textbooks were randomly selected. then they were analyzed manually to find the frequency of cohesive devices. cohesive devices include reference, substitution, ...

abstract the aim of this study was threefold: (1) to investigate the relationship between knowledge of semantic prosody and efl learners general language proficiency; (2) to examine the relationship between qualitative as well as quantitative knowledge of words, and (3) to compare the performance of efl learner on receptive and productive measures of semantic prosody. the study is based on a...