نتایج جستجو برای: energy bond gap
تعداد نتایج: 852533 فیلتر نتایج به سال:
In this study, the adsorption of 4-hydroxy phenyl-azobenzene on the surface of (4, 0) zigzag open-end boron nitride nanotube (BNNT) has been investigated by quantum calculations. In order to find the preferred adsorption site, different positions and orientations were considered. The impacts of donor-acceptor electron delocalization on the structural and electronic properties and reactivity of ...
The dioxygen molecule has been the subject of valence bond (VB) studies since 1930s, as it was considered as the first "failure" of VB theory. The object of this article is to provide an unambiguous VB interpretation for the nature of chemical bonding of the molecule by means of modern VB computational methods, VBSCF, BOVB, and VBCI. It is shown that though the VBSCF method can not provide quan...
antioxidants are made for the struggle and reconstruction of the damaged cells, because of their ability in destroying the free radicals. on account of their importance, a theoretical procedure was applied for the study of the molecular structure and radical scavenging activity of six hydroxyphenols which have been introduced as antioxidant compounds. all geometry structures were optimized by m...
To evaluate the effect of a dentin adhesive on sclerotie dentin, contraetion gap width and shear bond strength were measured, Dent{n cavity wall was pretreated with an experimental dentin bonding system w{th and without a dentin primer, or with a commercial dentin bonding system. In the experimental dentin bonding groups, contraction gap width of sclerotic dentin was signifieantly smaller than ...
In this work, the effects of inner radius and width variation on energy spectrum and persistent current in hexagonal graphene quantum rings with zigzag edges have been studied by using the tight-binding model. Our investigation show that the energy spectra of these rings are grouped into subbands which each one consists of six coupled energy levels that separated by energy gaps. The pattern o...
دست یابی به سیل ایده آل در ترمیم های کامپوزیتی یکی از مهمترین اهداف دندانپزشکی ترمیمی در سالهای اخیر بوده است. بررسی نفوذ رنگ رایج ترین شیوه مطالعه ریز نشت است. این روش از ارزیابی سه بعدی حساسیت کمتری دارد. به دلیل فقدان مطالعات ارزیابی ریزنشت کامپوزیت ها به روشfluid filtration در دندان های شیری، در این تحقیق بر آن شدیم تا میزان ریزنشت باندینگهایself etch و total etchرا در دندان های شیری به روش...
abstract the influence of cation?? and anion?? interactions on the strength and nature of n…h hydrogen bond has been investigated by quantum chemical calculations in s-triazine…3hf complex. ab initio calculations were performed at mp2/6-311++g(d,p) level of theory. the natural bond orbital (nbo) analysis and the bader’s quantum theory of atoms in molecules (aim) were also used to elucidate t...
ION REACTIONS The technique for estimation of activation energies for simple atom transfer reactions was developed by Johnston and coworkers (1963, 1966). The method is based upon the concept of conservation of bond order during the reaction process. Here bond order is defined as a number which is related to the strength of the chemical bond, hence bond energy-bond order (BEBO). In this notatio...
A tight binding molecular dynamics calculation has been conducted to study the size and coordination dependence of bond length and bond energy of Pd atomic clusters of 1.2-5.4 nm in diameter. It has been found that the bond contraction associated with bond energy increases in the outermost layer about 0.24 nm in a radial way, yet in the core interior the bond length and the bond energy remain t...
Abstract The effect of anharmonicity (coupling) in the field theory generally results dissipation plane waves. It has been appreciated that and ensuing waves can be accompanied by emergence gapped momentum state. Here, we show same lead to a energy state dispersion relation where frequency (energy) gap emerges explicitly. We discuss several notable properties states connections between them.
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