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...

abstract: in the paper of black and scholes (1973) a closed form solution for the price of a european option is derived . as extension to the black and scholes model with constant volatility, option pricing model with time varying volatility have been suggested within the frame work of generalized autoregressive conditional heteroskedasticity (garch) . these processes can explain a number of em...

chapter one is devoted to a moderate discussion on preliminaries, according to our requirements. chapter two which is based on our work in (24) is devoted introducting weighted semigroups (s, w), and studying some famous function spaces on them, especially the relations between go (s, w) and other function speces are invesigated. in fact this chapter is a complement to (32). one of the main fea...

1.0 overview it seems that grammar plays a crucial role in the area of second and foreign language learning and widely has been acknowledged in grammar research. in other words, teaching grammar is an issue which has attracted much attention to itself, and a lot of teachers argue about the existence of grammar in language teaching and learning. this issue will remind us a famous sentence f...

Biodiversity is one of the important concepts in ecology and vegetation management, and plays an important role in the health, production, and evaluation of ecosystems. Species diversity is a major part of biodiversity and one of the most important parameters of ecosystem changes. In this research, the data of the rangeland evaluation different climate zones of Isfahan province were used in fiv...

tourism , today as one of the ways to make money, create jobs , and social and political interactions is considered. this paper aims to examine the strengths and weaknesses of tourism development in mahmoud abad ( mazandaran ). the research method in this study is " descriptive - analytical " and to collection of data used field methods such as questionnaires and documentation - library. the sa...

چکیده: پژوهش حاضر به بررسی تطبیقی اعتماد اجتماعی در بین دبیران زن و مرد مقطع راهنمایی شهر ایلام می پردازد. امروزه در جوامع شاهد گسترش ارتباطات هستیم و با توجه به این که دامنه کنش های اجتماعی از حد روابط با آشنایان و دوستان فراتر رفته و به تعامل با کنشگران غربیه و نا آشنا گسترش یافته است، لزوم وجود اعتماد، بیش از پیش احساس می شود. اما با توجه به نقش دبیران در نهادهای آموزشی، در انتقال ارزش ها و...

abstract the variables affecting the nature of reading comprehension can be classified into two general categories: reader’s variables, and text variables (alderson, 2000). despite the wave of research on vocabulary knowledge as reader’s variable, the role of this knowledge in c-test as a text-dependent test and its interaction with lexical cohesion of the test as a text feature has remained a...

this study attempted to explore if teaching english collocations through two different modes of awareness-raising and input flooding has any possible differential effect on immediate retention as well as retention in a delayed assessment. it also compared the possible differential effect of teaching english collocations implicitly and explicitly on actively using the items in writing. m...