نتایج جستجو برای: constant return to scale
تعداد نتایج: 10753078 فیلتر نتایج به سال:
we describe here a suitable approach for the synthesis of n-unsubstituted monocyclic b-lactams under mild reaction conditions by the annelation of imines with substituted acetylchlorides. in this method the reaily available phtalimidoacetyl chloride were allowed to react with - dibenzylideneiminotoluene (hydrobenzamide) in the presence of an equimolar amount of triethylamine in refluxing toluen...
The cosmological constant is an unexplained until now phenomena of nature that requires an explanation through string effects. The apparent discrepancy between theory and experiment is enourmous and has already been explained several times by the author including mechanisms. In this work the string theory theory of abolished string modes is documented and given perturbatively to all loop orders...
this study examined the effects of collaborative strategic reading and direct instruction in persuasion on iranian high school students persuasive writing and attitudes. students in three intact classes were assigned to one of three treatment conditions: collaborative strategic reading and direct instruction in persuasion or direct instruction in persuasion or a control group. treatment effects...
introduction: the purpose of this research was to evaluate the performance of the hospitals’ managers affiliated to medical university of isfahan by data envelopment analysis (dea) method. also since some attributes of performance are qualitative, analytical hierarchy process (ahp) method was used also to quantify the data. methods: this research was practical in purpose and descriptive-analyti...
this study was conducted to investigate the impact of podcasts as a learning and teaching tool on iranian efl learners’ motivation for listening as well as on their listening comprehension ability. the study also investigated the learners’ perception towards listening to podcasts and examined whether the learners were likely to accept podcasts. out of fifty-five intermediate learners studying e...
nowadays enhancing critical thinking in learners is considered one of the foreign language teachers’ tasks due to its high position in foreign language classrooms. when it comes to selecting materials for language classrooms, there are obviously some criteria that teachers should apply. the present study aimed at a critical thinking based analysis of ten picture story books and ten folktales th...
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...
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