نتایج جستجو برای: shielding tensor

تعداد نتایج: 52172  

Journal: :Physical chemistry chemical physics : PCCP 2015
Thomas Spura Hossam Elgabarty Thomas D Kühne

We present an accelerated ab initio path-integral molecular dynamics technique, where the interatomic forces are calculated "on-the-fly" by accurate coupled cluster electronic structure calculations. In this way not only dynamic electron correlation, but also the harmonic and anharmonic zero-point energy, as well as tunneling effects are explicitly taken into account. This method thus allows fo...

Journal: :Journal of the American Chemical Society 2004
Cynthia J Jameson

We report, for the first time, a theoretical prediction of the (129)Xe nuclear magnetic resonance chemical shift tensor of xenon atom in a single crystal of silicalite at near-zero occupancy and the temperature dependence of the Xe NMR chemical shift tensor for the polycrystalline silicalite at maximum occupancy. The former is a measure of the sensitivity of the Xe tensor components to the loca...

Journal: :Journal of the American Chemical Society 2005
David L Bryce Alexander Grishaev Ad Bax

Incomplete motional averaging of chemical shift anisotropy upon weak alignment of nucleic acids and proteins in a magnetic field results in small changes in chemical shift. Knowledge of nucleus-specific chemical shift (CS) tensor magnitudes and orientations is necessary to take full advantage of these measurements in biomolecular structure determination. We report the determination by liquid cr...

Journal: :Journal of the American Chemical Society 2006
E Janette Ruiz Devin N Sears Alexander Pines Cynthia J Jameson

Cryptophane cages serve as host molecules to a Xe atom. Functionalization of cryptophane-A has permitted the development of Xe as a biosensor. Synthetic routes used to prepare cryptophanes result in racemic mixtures of the chiral cages. In the preparation of a tethered cryptophane-A cage for biosensor applications, some achiral and chiral substituents such as left-handed amino acids have been u...

Journal: :Inorganic chemistry 2007
Glen G Briand Andrew D Smith Gabriele Schatte Aaron J Rossini Robert W Schurko

The effect of subtle changes in the sigma-electron donor ability of 4-substituted pyridine ligands on the lead(II) coordination environment of (2,6-Me(2)C(6)H(3)S)(2)Pb (1) adducts has been examined. The reaction of 1 with a series of 4-substituted pyridines in toluene or dichloromethane results in the formation of 1:1 complexes [(2,6-Me(2)C(6)H(3)S)(2)Pb(pyCOH)](2) (3), [(2,6-Me(2)C(6)H(3)S)(2...

R. Gharibi T. Yazdanpanah

We introduce Banach algebras arising from tensor norms. By these Banach algebras we make Arensregular Banach algebras such that tensor product becomes irregular, where is tensor norm. Weillustrate injective tensor product, does not preserve bounded approximate identity and it is notalgebra norm.

In this paper, we calculate the relativistic bulk tensor and shear tensor of the relativistic accretion ows in the Kerr metric, overall and without any approximation. We obtain the relations of all components of the relativistic bulk and shear tensor in terms of components of four-velocity and its derivatives, Christoffel symbols and metric components in the BLF. Then, these components are deri...

In this paper, we study the tensor commutativity degree of pair of finite groups. Erdos introduced the relative commutativity degree and studied its properties. Then, Mr. Niroomand introduced the tensor relative commutativity degree, calculated tensor relative degree for some groups, and studied its properties. Also, he explained its relation with relative commutativity degree. In this paper, w...

Journal: :international journal of pediatrics 0
vahid karami department of medical physics, school of medicine, ahvaz jundishapur university of medical sciences, ahvaz, iran. mansour zabihzadeh department of medical physics, school of medicine, student research committee, ahvaz jundishapur university of medical sciences, ahvaz, iran and department of clinical oncology, golestan hospital, ahvaz jundishapur university of medical sciences, ahvaz, iran nasim shams department of oral and maxillofacial radiology, school of dentistry, ahvaz jundishapur university of medical sciences, ahvaz, iran saman sarikhani department of radiology, school of medicine, ahvaz jundishapur university of medical sciences, ahvaz, iran.

background: gonad shielding has been recommended during pelvic x-rays since the 1950s. the popular method of gonad shielding is placement a lead shield in the midline of the pelvis. the aim of this study was to evaluate the prevalence and utility of gonad shielding in pediatrics undergoing pelvic x-rays.materials and methodsfollowing study approval, we retrospectively retrieved data from the di...

Journal: :health scope 0
vida zaroushani department of occupational health engineering, faculty of medical sciences, tarbiat modares university, tehran, ir iran ali khavanin department of occupational health engineering, faculty of medical sciences, tarbiat modares university, tehran, ir iran; department of occupational health engineering, faculty of medical sciences, tarbiat modares university, tehran, ir iran. tel: +98-2182883849, fax: +98-2182883825 seyed bagher mortazavi department of occupational health engineering, faculty of medical sciences, tarbiat modares university, tehran, ir iran ahmad jonidi jafari department of environmental health engineering, school of public health, iran university of medical sciences, tehran, ir iran

results the results showed that the epoxy plates 6 and 2 mm thick had the highest and the lowest averages of shielding effectiveness at 4.48 db and 1.90 db, respectively. however, increasing the thickness was useful up to 4 mm. in addition, in a similar attenuation pattern, x-band frequency was divided into lower, middle, and upper sections. the lower section had the highest shielding effective...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید