نتایج جستجو برای: 2 demonstrate the step
تعداد نتایج: 16514541 فیلتر نتایج به سال:
pollution has become a very serious threat to our environment. monitoring pollution is the rst step toward planning to save the environment. the use of dierential equations, monitoring pollution has become possible. in this paper, a ritz-collocation method is introduced to solve non-linear oscillatory systems such as modelling the pollution of a system of lakes. the method is based upon bernoul...
the space now known as complete erdos space ec was introduced by paul erdos in 1940 as the closed subspace of the hilbert space ?2 consisting of all vectors such that every coordinate is in the convergent sequence {0} ? { 1 n : n ? n}. in a solution to a problem posed by lex g. oversteegen we present simple and useful topological characterizations of ec. as an application we determine the ...
We apply the dressing method to a string solution given by a static string wrapped around the equator of a three-sphere and find that the result is the single spike solution recently discussed in the literature. Further application of the method allows the construction of solutions with multiple spikes. In particular we construct the solution describing the scattering of two single spikes and c...
A reliable speech enhancement method is important for speech applications as a pre-processing step to improve their overall performance. In this paper, we propose a novel frequency domain method for single channel speech enhancement. Conventional frequency domain methods usually neglect the correlation between neighboring time-frequency components of the signals. In the proposed method, we take...
بررسی تنوع ژنتیکی ژنوتیپهای بومی پیاز ایرانی در مقایسه با انواع خارجی چکیده: برنامه های اصلاحی گیاهان بر اساس تنوع و انتخاب صفات برتر کمی و کیفی صورت می گیرد. لذا، ارزیابی تنوع ژنتیکی، اولین مرحله در برنامه های اصلاحی است. در این راستا، استفاده از روش های جدید مطالعهی تنوع ژنتیکی ضروری به نظر می رسد. در این بررسی تعیین تنوع ژنتیکی سیزده ژنوتیپ پیاز ایرانی در مقایسه با دو ژنوتیپ خارجی با است...
chromanone derivatives demonstrate remarkable cytotoxity against a varieties of cancer cell lines. novel 9-[hydroxy(substitutedphenyl)methyl]-2,2-dimethyl-2,3,8,9- tetrahydro-4h,10h-pyrano[2,3-f]chromene-4,10-diones as glyasperin analogues were synthesized in four steps from known 4-chromone 1. the key step was the preparation of chromane dione 5a by regioselective intramolecular cyclization re...
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...
this work is presented in five parts. in the first part preparation of the starting complex [pt(c^n)cl(dmso)], 1, in which c^n = n(1),c(2?)-chelated, deprotonated 2-phenylpyridine, and dmso = dimethylsulfoxide, and its reaction with 1 equiv of the biphosphine ligands bis(diphenylphosphino)amine, dppa, or bis(diphenylphosphino)methane, dppm, to give the complex [pt(c^n)cl(dppa)], 2, or [pt(c^n)c...
هدف تحقیق حاضر بررسی تاثیر نشانه های فرا گفتمان متنی بر فهم متون انگلیسی به وسیله ی زبان اموزان فارسی زبان است.این تحقیق علاوه بر این کوشیده است تا میزان اگاهی این زبان اموزان و نحوه ی تعامل انان را با متون خوانده شده در زبان انگلیسی به وسیله ی پرسش نامه ی تهیه شده بررسی کند.بر اساس محتوای یک متن انگلیسی یازده سوال درست /غلط طرح گردید و یک مرتبه با ان متن و یک مرتبه با نسخه ای که نشانه ها...
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