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Shielding Calculations for Civil Defense
Health Physics, 1960How the -ray penetration theory developed at the National Bureau of Standards has been applied to fall-out shielding problems is discussed. The concepts of barrier shielding and geometry shielding are discussed, and some comparison with experiment is given. The proposed publication of results is also described. (auth)
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Shielding Calculations: IGLO Method
2007The sections in this article are 1 Introduction 2 The Hamiltonian in a Magnetic Field and the Gauge Problem 3 Chemical Shifts 4 Basic Principles of the IGLO Method 5 DIGLO and MC-IGLO 6 Some Results and Applications 7 Correlation and Relativistic Effects 8 Biographical Sketches Related ...
Werner Kutzelnigg +2 more
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Shielding Calculations: GIAO Methods
2011The article discusses the calculation of NMR shieldings by molecular orbital methods, and analyzes the gauge problem that arises in these calculations. In its simplest form, the gauge problem is the unphysical dependence of the calculated results on the position of the molecule (or the arbitrary gauge origin) in the coordinate frame.
Gábor Magyarfalvi +3 more
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Research on Shielding Effectiveness Calculation Method of Electromagnetic Shielding Materials
Solid State Phenomena, 2020Electromagnetic shielding materials are widely used in engineering. Shielding effectiveness is an important index to measure the shielding effect of electromagnetic shielding materials. A method for calculating the shielding effectiveness of electromagnetic shielding materials is discussed in this paper.
Nan Mei +6 more
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On the shielding effectiveness calculation
Computing, 2013Numerical analysis of the effectiveness of electromagnetic shielding is performed. Its first objective is to propose a new approach to the shielding effectiveness theory based on a high-frequency numerical model that uses integral characteristics in contrast with the standard model.
Kubík Zdeněk +3 more
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Calculations of nuclear electric shielding in molecules
Chemical Physics Letters, 1980Abstract The electric shielding tensor at nuclei in the molecules H 2 O, NH 3 , CH 4 and CO has been evaluated via coupled Hartree-Fock perturbation theory. The average trace of the shielding tensor is linearly dependent on atomic electronegativities in the isoelectronic series H 2 O, NH 3 , CH 4 .
P. Lazzeretti, ZANASI, Riccardo
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2007
The sections in this article are 1 Introduction 2 The Use of Calculations of Chemical Shielding Tensors for the Assignment of the Orientations of the Principal Values Obtained from Disordered Samples 3 The Use of Chemical Shielding Tensor Calculations for the Assignment of 13C Resonances in the Solid Phase 4 Studies of the Additivity ...
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The sections in this article are 1 Introduction 2 The Use of Calculations of Chemical Shielding Tensors for the Assignment of the Orientations of the Principal Values Obtained from Disordered Samples 3 The Use of Chemical Shielding Tensor Calculations for the Assignment of 13C Resonances in the Solid Phase 4 Studies of the Additivity ...
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A comparison of calculated NMR shielding probes
Journal of Molecular Graphics and Modelling, 2004In a strong magnetic field, covalently bonded hydrogen nuclei located over the plane of an anisotropic pi bond-containing functional group experience magnetic shielding (or deshielding) that results from the combined effect of the magnetic anisotropy of the functional group and other nearby covalent bonds plus other intramolecular shielding effects ...
Ned H, Martin +2 more
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Dose calculations about shielded gynecological colpostats
International Journal of Radiation Oncology*Biology*Physics, 1990Although shielded gynecological colpostats have been shown experimentally to reduce doses to bladder and rectal tissue by as much as 50%, nearly all previously described dose computation algorithms ignore applicator heterogeneities. We describe the use of realistic Monte Carlo calculations to study the dosimetric effects of applicator structure. Use of
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The Journal of Chemical Physics, 2005
Two expressions for nuclear-magnetic-shielding tensor components based on analytically differentiating the electronic energy of a system are presented. The first is based on a second-order Douglas-Kroll-Hess approach, in which the off-diagonal block terms of the transformed Dirac Hamiltonian are diminished to second order with respect to both the ...
K, Kudo, H, Fukui
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Two expressions for nuclear-magnetic-shielding tensor components based on analytically differentiating the electronic energy of a system are presented. The first is based on a second-order Douglas-Kroll-Hess approach, in which the off-diagonal block terms of the transformed Dirac Hamiltonian are diminished to second order with respect to both the ...
K, Kudo, H, Fukui
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