Plateforme d'Enseignement à Distance de l'Université Oran 1 Ahmed Ben Bella
مدونة الموقع
أي شخص بالعالم
In this short paper, we present an interesting and welcome connection between two different approaches to the mathematical structure of the standard genetic code, we have considered in the last years. The first one relies on the use of the unique number 23! and the second is based on the atomic composition of the four ribonucleotides UMP, CMP, AMP and GMP, the building-blocks of RNA, where several Fibonacci numbers are seen to occur.
[ تم التعديل: الجمعة، 29 مايو 2020، 10:48 PM ]
أي شخص بالعالم
محاضرات مقياس مخبر السمعي البصري ماستر السداسي الثاني تخصص سمعي بصري الدكتور بن دريس أحمد
عزيزي الطالب تجد في الملف المدرج أسفله ملخص عن محاضرات المقياس إضافة للمحاضرات التي قمنا بتقديمها قبل الحجر
وفقك الله
[ تم التعديل: الجمعة، 9 فبراير 2024، 7:30 PM ]
أي شخص بالعالم
[ تم التعديل: السبت، 9 مايو 2020، 3:12 PM ]
أي شخص بالعالم
Abstract
Quantum mechanical studies were carried out in order to understand and describe the nature and strength of the hydrogen bond topology in three dimensional water cluster systems (H2O)n, in the size range 6–20 molecules. Optimal structures and vibrational frequencies of cage like water clusters are computed at the Hartree–Fock (HF) and the electronic density functional theory (DFT) level of theory with a detailed data analysis. Theoretical results are compared to experimental data when available. The general tendency is a decrease of the global minimum energy as the cluster size increases. The nearest neighbour separation between oxygen atoms decreases exponentially when the cluster size increases. The present work suggests that DFT results are in a good agreement with the corresponding HF data, however slight differences remain with regard to values of the nearest neighbour separation between oxygen atoms. The Morokuma’s decomposition of the total interaction energy performed on two and three-dimensional clusters lead to a better understanding of the cluster formation with a strong polarization energy component.
