نتایج جستجو برای: n level
تعداد نتایج: 1965004 فیلتر نتایج به سال:
Let $R$ be a ring, and let $n, d$ be non-negative integers. A right $R$-module $M$ is called $(n, d)$-projective if $Ext^{d+1}_R(M, A)=0$ for every $n$-copresented right $R$-module $A$. $R$ is called right $n$-cocoherent if every $n$-copresented right $R$-module is $(n+1)$-coprese-nted, it is called a right co-$(n,d)$-ring if every right $R$-module is $(n, d)$-projective. $R$...
single-valence electron atoms are an important class of atoms. their oscillator strengths are their important properties. knowing the oscillator strengths one can easity calculate the transition probabilities of the spectral lines and hence the lifetimes of energy levels of most atoms. the oscillator strengths of the spectral lines of most atoms are not knoen with sufficient accuracy due to the...
An assessment of the nitrogen fertilization efficiency should not only include quantitativeand qualitative yield changes, but also an analysis of formation some indicators such as: Nharvest index (NHI), N use efficiency (NUE), N utilization efficiency (NUtE), N agronomicefficiency (NAE), N physiological efficiency (NPE) and N apparent recovery fraction (NRF).The objective of the study was the e...
it is definitely necessary to understand the concept and behavior of causation of life insurance policies and its determinants for insurance managers, regulators, and customers. for insurance managers, the profitability and liquidity of insurers can be increasingly influenced by the number of causation through costs, adverse selection, and cash surrender values. therefore, causation is a materi...
abstract this study examines the relationship between reading anxiety and difficulty of texts as well as the relationship between reading anxiety and students perceived difficulty of the texts. since difficulty is a relative concept, i limited its definition by sticking to the readability formula. we also took students perceived difficulty levels into account. therefore, in the present study, ...
the fullerene structures of c20cage and bowl,c20h10 and their n-doped structures as c20cage nh,c20bowl nh, c20h10nh, c20h10n and their isomers are optimized using the mpw1pw91/6-31g level of the theory. magnetic shielding tensors of 14n and 13c atoms are calculated by the same level of the theory. results show that doping an n atom on fullerenes affects differently on the chemical shielding of ...
The fullerene structures of C20cage and bowl,C20H10 and their N-doped structures as C20cage NH,C20bowl NH, C20H10NH, C20H10N and their isomers are optimized using the MPW1PW91/6-31G level of the theory. Magnetic shielding tensors of 14N and 13C atoms are calculated by the same level of the theory. Results show that doping an N atom on fullerenes affects differently on the chemical shielding of ...
substitution of two or four carbon atoms by nitrogen in the corannulene molecule as a carbon nanostructure was done and the obtained structures were optimized at mp2/6-31g(d) level of theory. calculations of the nucleus-independent chemical shift (nics) were performed to analyze the aromaticity of the corannulene rings and its derivatives upon doping with n at b3lyp/6-31g(d) level of theory. re...
Background: The 25-hydroxyvitamin D3(25-OH D3)deficiency is a common problem worldwide, and it is aprevalent incidence in neonates. Different studies investigated the relationship of vitamin D deficiency with neonatal mortality and morbidity. This study aimed to evaluate the relationship between vitamin D deficiency and respiratory distress in preterm neonates.Methods: A prospective cohor...
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