Let G be a graph and let mij (G), i, j≥1, be the number of edges uv of G such that {dv (G), du (G)}={i, j} The M -polynomial of G is introduced with m(g; x, y)=å i≤j mij(G) xi yj It is shown that degree-based topological indices can be routinely computed from the polynomial, thus reducing the problem of their determination in each particular case to the single problem of determining the M -polynomial. The new approach is also illustrated with examples.

در دنیای پیشرفته امروز، به ویژه در حوزه های مهندسی مکانیک و صنایع هوافضا، کامپوزیت ها به دلیل ویژگی منحصربه فرد استحکام بالا در کنار وزن کم، جایگاه برجسته ای یافته اند. با این حال، رفتار پیچیده این مواد، تحلیل دقیق و ابزارهای پیشرفته ای را برای مدل سازی و پیش بینی آسیب های ساختاری آن ها می طلبد. پژوهش حاضر با بهره گیری از ترکیب مدل های چندمقیاسی مزو-ماکرو و مفاهیم مکانیک آسیب پیوسته، رویکردی نوین برای تحلیل و ارزیابی خرابی در ساختارهای کامپوزیتی ارائه می کند. این مطالعه از چارچوب مدل های چندمقیاسی شبه همزمان بهره می گیرد که با استفاده از روش های پیشرفته شبیه سازی المان محدود و ابزارهای پردازش تصویر، امکان تحلیل جامع ترک خوردگی زمینه و شکست الیاف را فراهم می سازد. افزون بر این، زیربرنامه ای مبتنی بر مفاهیم مکانیک خرابی پیوسته در نرم افزار المان محدود میتوان توسعه داد که قادر باشد تکامل آسیب ها، از جمله پیشرفت ترک ها، شکست الیاف و پیش بینی بار نهایی شکست سازه های کامپوزیت را به صورت پیش رونده تحلیل کند. از سوی دیگر، به کارگیری روش های هوش مصنوعی، به ویژه در پردازش تصویر، سبب کاهش زمان و هزینه های محاسباتی شده و دقت تحلیل های مکانیکی را به طرز چشمگیری افزایش داده است. این رویکردهای چندمقیاسی هوشمند نقشی کلیدی در بهینه سازی طراحی و پیش بینی دقیق مکانیزم های خرابی ایفا می کنند. این روش ها، به ویژه در کاربردهای پیچیده و حساس هوافضایی، ابزارهای مؤثری برای ارتقای عملکرد و قابلیت اطمینان ساختارهای کامپوزیت ها به شمار می روند.

In this article the writer has discussed the following question: the necessity of establishing ideal cultural standards in the following areas: the equality of the rights of all citizens, boosting the public welfare, respecting human dignity, guarding individual freedom; observing social discipline, protecting the environment, advocating the partnership of all people in political and social issues with the aim of realizing human and sustainable development in the civil society.The writer has also touched upon the keys concepts of culture, urbanization, sustainable development,discussing the relationship between them.

In this technical paper, the author, who is a professor of linguistics, examines the question of sentence stress in the Persian language in simple sentences. He states at the outset that word stress in Persian usually falls on the last syllable of the word. But not so, the question of sentence stress, which is complicated by a number of factors, such as the intent of the speaker. He then analyses in detail the different elements of the sentence, and points out how these may be stressed depending on the circumstances surrounding the sentence. And he succeeds in formulating a general rule for those sentences in which the predicate consists of more than one group of words. "In these, the sentence stress does not fall on the verb or the verbal core of the verb group. It falls, rather, on the last syllable of the word preceding the verbal core."

Estimation of optimum fertilizer rates is needed because of growing economic and environmental concerns. Optimum fertilizer rates can be determined by fitting statistical models to yield data collected from N fertilizer experiments. The main goal of this research was to compare and evaluate quadratic, square root, Mitscherlich, rectangular hyperbola, linear plus plateau and quadratic plus plateau models for describing the response of sugar beet to N fertilizer. Data used were obtained from a furrow irrigation system experiment with five N fertilizer rates: zero (control), 60, 120, 180, and 240 N kgha-1 with three replications in Ekbatan Research Station, Hamedan, Iran, during 2003 and 2004. Economic optimum N fertilizer rates were obtained based on fertilizer and sugar beet price during 2003 and 2004. Economic, optimum N fertilizer rates varied depending on the fertilizer to crop price ratio and models used. Results of this research showed the quadratic model described the yield responses and economic, optimum N fertilizer rate in sugar beet cultivation better than the other models. Economic, optimum N fertilizer rates due to this model were 235.8 and 248.9 kgha-1 in 2001 and 2002, respectively. Economic optimum N fertilizer rates based on N fertilizer subsidy and non-subsidy prices were 234.7 and 225.1 kgha-1 for 2003 model, and 247.9 and 240.8 kgha-1 for 2004 model, respectively.

Translation is to say something said or written in another language. The principal task of the translator is to render the source language propositions into the target language. The mere faithfulness, however, does not necessarily result in the establishment of rapport between the writer of the source text and the reader of the translation. Translators are also responsible to preserve the information structure in the target language. For Functional Sentence Perspective (FSP), the information conveyed by a sentence is of two parts. One part is believed by the speaker to be shared with the addressee, the other part being totally new for him. The speaker, usually, does not reveal the new information, before the old information. The old information is referred to as "theme", and whatever said about it is referred to as "rheme". The relation between the theme and rheme comprises the information structure of the sentence. This article aims to compare the information structure in the English book "A Short History of Linguistics" and its Persian translation.