منابع مشابه
the effect of traffic density on the accident externality from driving the case study of tehran
در این پژوهش به بررسی اثر افزایش ترافیک بر روی تعداد تصادفات پرداخته شده است. به این منظور 30 تقاطع در شهر تهران بطور تصادفی انتخاب گردید و تعداد تصادفات ماهیانه در این تقاطعات در طول سالهای 89-90 از سازمان کنترل ترافیک شهر تهران استخراج گردید و با استفاده از مدل داده های تابلویی و نرم افزار eviews مدل خطی و درجه دوم تخمین زده شد و در نهایت این نتیجه حاصل شد که تقاطعات پر ترافیک تر تعداد تصادفا...
15 صفحه اولAbsence of Short-Term Variability of CTA 102.
Short-time variations in intensity of about 40 percent, with a period of the order of 100 days, have been reported for the quasistellar radio source CTA 102 at 32.5-centimeter wavelength. We have observed CTA 102 at 25.5-centimeter wavelength over a 67-day, period and have detected no significant variations of intensity.
متن کاملthe effect of creative writing instruction on lexical density of advanced efl learners writing
چکیده ندارد.
15 صفحه اولCompact Symmetric Objects as Radio Flux Density Calibrators
We present results from the first intensive monitoring campaign of a sample of Compact Symmetric Objects (CSOs). We observed seven CSOs at 8.5 GHz over a period of eight months, with an average spacing between observations of 2.7 days. Our results show that, as predicted, the flux densities of the CSOs are extremely stable; the mean RMS variability of the sample was 0.7% in flux density. The lo...
متن کاملCOMPTEL observations of the γ-ray blazars 3C 454.3 and CTA 102 during the CGRO mission
We have investigated the MeV behaviour of the γ-ray blazars 3C 454.3 and CTA 102 by analyzing all COMPTEL observations of this sky region during the complete CGRO mission. Both sources are detected by COMPTEL at the upper COMPTEL energies, although their flux estimates may be uncertain by possible minor contributions of nearby unidentified EGRET γ-ray sources. While CTA 102 was only detected at...
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ژورنال
عنوان ژورنال: Nature
سال: 1965
ISSN: 0028-0836,1476-4687
DOI: 10.1038/2061241a0