Downloads & Free Reading Options - Results

We develop a Green's function approach to quasiparticle excitations of open-shell systems within the GW approximation. It is shown that accurate calculations of the characteristic multiplet structure require a precise knowledge of the self energy and, in particular, its poles. We achieve this by constructing the self energy from appropriately chosen mean-field theories on a fine frequency grid. We apply our method to a two-site Hubbard model, several molecules and the negatively charged nitrogen-vacancy defect in diamond, and obtain good agreement with experiment and other high-level theories.

We calculate the bulk photovoltaic response of the ferroelectrics BaTiO$_3$ and PbTiO$_3$ from first principles by applying "shift current" theory to the electronic structure from density functional theory. The first principles results for BaTiO$_3$ reproduce eperimental photocurrent direction and magnitude as a function of light frequency, as well as the dependence of current on light polarization, demonstrating that shift current is the dominant mechanism of the bulk photovoltaic effect in BaTiO$_3$. Additionally, we analyze the relationship between response and material properties in detail. The photocurrent does not depend simply or strongly on the magnitude of material polarization, as has been previously assumed; instead, electronic states with delocalized, covalent bonding that is highly asymmetric along the current direction are required for strong shift current enhancements. The complexity of the response dependence on both external and material parameters suggests applications not only in solar energy conversion, but to photocatalysis and sensor and switch type devices as well.

Simulations of defects in paramagnetic materials at high temperature constitute a formidable challenge to solid state theory due to the interaction of magnetic disorder, vibrations, and structural relaxations. CrN is a material where these effects are particularly large due to a strong magneto-lattice coupling and a tendency for deviations from the nominal 1:1 stoichiometry. In this work we present a first-principles study of nitrogen vacancies and nitrogen interstitals in CrN at elevated temperature. We report on formation energetics, the geometry of interstital nitrogen dimers, and impact on the electronic structure caused by the defects. We find a vacancy formation energy of 2.28 eV with a small effect of temperature, a formation energy for N interstitial in the form of a $\big $ oriented split-bond of 3.77 eV with an increase to 3.97 at 1000 K. Vacancies are found to add three electrons while split bond interstitial adds one electron to the conduction band. The band gap of defect-free CrN is smeared out due to vibrations, though it is difficult to draw conclusion about the exact temperature at which the band gap closes from our calculations. However, it is clear that at 900 K there is a non-zero density of electronic states at the Fermi level. At 300 K our results indicate a boarder case were the band-gap is about to close.

We performed density functional theory (DFT) calculations for a bi-layered heterostructure combining a graphene layer with a MoS2 layer with and without intercalated Li atoms. Our calculations demonstrate the importance of the van der Waals (vdW) interaction, which is crucial for forming stable bonding between the layers. Our DFT calculation correctly reproduces the linear dispersion, or Dirac cone, feature at the Fermi energy for the isolated graphene monolayer and the band gap for the MoS2 monolayer. For the combined graphene/MoS2 bi-layer, we observe interesting electronic structure and density of states (DOS) characteristics near the Fermi energy, showing both the gap like features of the MoS2 layer and in-gap states with linear dispersion contributed mostly by the graphene layer. Our calculated total density of states (DOS) in this vdW heterostructure reveals that the graphene layer significantly contributes to pinning the Fermi energy at the center of the band gap of MoS2. We also find that intercalating Li ions in between the layers of the graphene/MoS2 heterostructure enhances the binding energy through orbital hybridizations between cations (Li adatoms) and anions (graphene and MoS2 monolayers). Moreover, we calculate the dielectric function of the Li intercalated graphene/MoS2 heterostructure, the imaginary component of which can be directly compared with experimental measurements of optical conductivity in order to validate our theoretical prediction. We observe sharp features in the imaginary component of the dielectric function, which shows the presence of a Drude peak in the optical conductivity, and therefore metallicity in the lithiated graphene/MoS2 heterostructure.

We performed density functional theory (DFT) calculations for a bi-layered heterostructure combining a graphene layer with a MoS2 layer with and without intercalated Li atoms. Our calculations demonstrate the importance of the van der Waals (vdW) interaction, which is crucial for forming stable bonding between the layers. Our DFT calculation correctly reproduces the linear dispersion, or Dirac cone, feature at the Fermi energy for the isolated graphene monolayer and the band gap for the MoS2 monolayer. For the combined graphene/MoS2 bi-layer, we observe interesting electronic structure and density of states (DOS) characteristics near the Fermi energy, showing both the gap like features of the MoS2 layer and in-gap states with linear dispersion contributed mostly by the graphene layer. Our calculated total density of states (DOS) in this vdW heterostructure reveals that the graphene layer significantly contributes to pinning the Fermi energy at the center of the band gap of MoS2. We also find that intercalating Li ions in between the layers of the graphene/MoS2 heterostructure enhances the binding energy through orbital hybridizations between cations (Li adatoms) and anions (graphene and MoS2 monolayers). Moreover, we calculate the dielectric function of the Li intercalated graphene/MoS2 heterostructure, the imaginary component of which can be directly compared with experimental measurements of optical conductivity in order to validate our theoretical prediction. We observe sharp features in the imaginary component of the dielectric function, which shows the presence of a Drude peak in the optical conductivity, and therefore metallicity in the lithiated graphene/MoS2 heterostructure.

We performed density functional theory (DFT) calculations for a bi-layered heterostructure combining a graphene layer with a MoS2 layer with and without intercalated Li atoms. Our calculations demonstrate the importance of the van der Waals (vdW) interaction, which is crucial for forming stable bonding between the layers. Our DFT calculation correctly reproduces the linear dispersion, or Dirac cone, feature at the Fermi energy for the isolated graphene monolayer and the band gap for the MoS2 monolayer. For the combined graphene/MoS2 bi-layer, we observe interesting electronic structure and density of states (DOS) characteristics near the Fermi energy, showing both the gap like features of the MoS2 layer and in-gap states with linear dispersion contributed mostly by the graphene layer. Our calculated total density of states (DOS) in this vdW heterostructure reveals that the graphene layer significantly contributes to pinning the Fermi energy at the center of the band gap of MoS2. We also find that intercalating Li ions in between the layers of the graphene/MoS2 heterostructure enhances the binding energy through orbital hybridizations between cations (Li adatoms) and anions (graphene and MoS2 monolayers). Moreover, we calculate the dielectric function of the Li intercalated graphene/MoS2 heterostructure, the imaginary component of which can be directly compared with experimental measurements of optical conductivity in order to validate our theoretical prediction. We observe sharp features in the imaginary component of the dielectric function, which shows the presence of a Drude peak in the optical conductivity, and therefore metallicity in the lithiated graphene/MoS2 heterostructure.

A complete treatise of practical navigation demonstrated from it's first principles: together with all the necessary tables. To which are added, the useful theorems of mensuration, surveying, and gauging; ... By Archibald Patoun, ... The second edition. 1739.. Digitized from IA40310403-66 . Previous issue: bim_eighteenth-century_anthropologia-nova-or-_drake-james_1717_2 . Next issue: bim_eighteenth-century_report-of-william-chapma_chapman-william_1793 .

Using first-principles based Density Functional Theory (DFT), we have investigated the structural instabilities in the austenite phases of Mn$_{2}$Ni{\it X} ({\it X}= Al, Ga, In, Sn) magnetic shape memory alloys (MSMA). A complete softening is observed in the acoustic TA$_{2}$ branches for all the materials along [$\xi\xi$0] directions leading to the instability in the austenite structure which effectively stabilizes into martensitic structure. The reasons behind this softening are traced back to the repulsion from the optical T$_{2g}$ branches and to the nesting features in the Fermi surfaces. The vibrational density of states, the force constants and the elastic moduli are also computed and analyzed, which reconfirm the underlying mechanism behind the instabilities. The results indicate that the phonon anomalies are related to the occurrence of possible pre-martensitic phases which can be quite complex.

In seven-shape notation

In seven-shape notation

Book digitized by Google from the library of the University of Michigan and uploaded to the Internet Archive by user tpb.

Book digitized by Google from the library of the University of Michigan and uploaded to the Internet Archive by user tpb.

Book digitized by Google from the library of Oxford University and uploaded to the Internet Archive by user tpb.

Book digitized by Google from the library of Oxford University and uploaded to the Internet Archive by user tpb.

Book digitized by Google from the library of Harvard University and uploaded to the Internet Archive by user tpb.

Book digitized by Google from the library of Harvard University and uploaded to the Internet Archive by user tpb.

Book digitized by Google from the library of Harvard University and uploaded to the Internet Archive by user tpb.

Book digitized by Google from the library of Harvard University and uploaded to the Internet Archive by user tpb.

154 pages ; 19 cm

154 pages ; 19 cm

Bookseller's advertisement: v. 3, p. [1] at the end

Bookseller's advertisement: v. 3, p. [1] at the end

We describe, within an ab-initio approach, the stabilization of the tetragonal phase vs. the monoclinic one in Yttrium-doped Zirconia. The process is believed to be influenced from different mechanisms. Indeed we show that there is a delicate balance between the change in electrostatic and kinetic energy and exchange-correlation effects. In the tetragonal phase the perturbation induced by doping is better screened at the price of sacrificing correlation energy. Our work opens the opportunity to use the same approach to predict the tetragonal phase stabilization of materials like Zirconia or Hafnia, with different and less characterized dopants.

"On the First Principles of the Calculus" is an article from The Analyst, Volume 2 . View more articles from The Analyst . View this article on JSTOR . View this article's JSTOR metadata . You may also retrieve all of this items metadata in JSON at the following URL: https://archive.org/metadata/jstor-2635827

Flake

Flake

"Bibliographical note": pages 455-460. "Checklist of Willa Cather's critical and personal writing, 1891-1896": pages 461-477

The metadata below describe the original scanning. Follow the "All Files: HTTP" link in the "View the book" box to the left to find XML files that contain more metadata about the original images and the derived formats (OCR results, PDF etc.). See also the What is the directory structure for the texts? FAQ for information about file content and naming conventions.

Using the density functional theory (DFT) formulated within the framework of the plane-wave basis projector augmented wave (PAW) method, the temperature-dependent elastic properties of MgRE (RE=Y, Dy, Pr, Sc, Tb) intermetallics with B2-type structure are presented from first-principles. Our calculations are based on the fact that the elastic moduli as a function of temperature mainly results from thermal expansion. The comparison between the predicted results and the available experimental data for a benchmark material NiAl provides good agreements. At $T=0K$, our calculated values of lattice parameter and elastic moduli for MgRE intermetallics show excellent agreement with previous theoretical results and experimental data. While temperature increases, we find that the elastic constants decrease and approach linearity at higher temperature and zero slope around zero temperature.

Using the density functional theory (DFT) formulated within the framework of the plane-wave basis projector augmented wave (PAW) method, the temperature-dependent elastic properties of MgRE (RE=Y, Dy, Pr, Sc, Tb) intermetallics with B2-type structure are presented from first-principles. Our calculations are based on the fact that the elastic moduli as a function of temperature mainly results from thermal expansion. The comparison between the predicted results and the available experimental data for a benchmark material NiAl provides good agreements. At $T=0K$, our calculated values of lattice parameter and elastic moduli for MgRE intermetallics show excellent agreement with previous theoretical results and experimental data. While temperature increases, we find that the elastic constants decrease and approach linearity at higher temperature and zero slope around zero temperature.

The electronic structure of an isostructural series of molecular conductors, {\beta}'-X[Pd(dmit)_2]_2 is systematically studied by a first-principles method based on the density-functional theory. The calculated band structures are fitted to the tight-binding model based on Pd(dmit)_2 dimers on the triangular lattice. We find systematic variation in the anisotropy of the transfer integrals along the three directions of the triangular lattice taking different values. The transfer integral along the face-to-face stacking direction of Pd(dmit)_2 dimers is always the largest. Around the quantum spin liquid, X = EtMe_3Sb, the other two transfer integrals become comparable. We also report sensible differences in the distribution of wavefunctions near the Fermi level between the two dmit ligands of the Pd(dmit)_2 molecule.

We show that the position and width of the plasmon resonance in Silver are correctly predicted by ab--initio calculations including self--energy effects within the GW approximation. Unlike in simple metals and semiconductors, quasiparticle corrections play a key role and are essential to obtain Electron Energy Loss in quantitative agreement with the experimental data. The sharp reflectance minimum at 3.92 eV, that cannot be reproduced within DFT--LDA, is also well described within GW.The present results solve two unsettled drawbacks of linear response calculations for Silver.

A sermon from The Three Fundamental Principles.

Recent experiments on Mn doped multiferroic $CoCr_{2}O_{4}$ indicate that a possible distribution of Mn atoms among tetrahedrally and octahedrally coordinated sites in the spinel lattice give rise to different variations in the structural parameters and saturation magnetisations in different concentration regimes of Mn atoms substituting the Cr. A composition dependent magnetic compensation behaviour points to the role conversions of the magnetic constituents. In this work, we have investigated the thermodynamics of cation disorder in $Co\left(Cr_{1-x}Mn_{x}\right)_{2}O_{4}$ system and it's consequences on the structural, electronic and magnetic properties, using results from first-principles electronic structure calculations. We have computed the variations in the cation-disorder as a function of Mn concentration and the temperature and found that at the annealing temperature of the experiment many of the systems exhibit cation disorder. Our results support the interpretations of the experimental results regarding the qualitative variations in the sub-lattice occupancies and the associated magnetisation behaviour, with composition. We have analysed the variations in structural, magnetic and electronic properties of this system with variations in the compositions and the degree of cation disorder from the variations in their electronic structures and by using the ideas from crystal field theory. Our study provides a complete microscopic picture of the effects that are responsible for composition dependent behavioural differences of the properties of this system. This work lays down a general framework, based upon results from first-principles calculations, to understand and analyse the substitutional magnetic spinel oxides $A\left(B_{1-x}C_{x} \right)_{2}O_{4}$ in presence of cation disorder.

In this work we provide an elementary derivation of the indefinite spin groups in low-dimensions. Our approach relies on the isomorphism of Cl(p+1, q+1) to the algebra 2x2 matrices with entries in Cl(p,q), simple properties of Kronecker products, characterization of when an even dimensional real (resp. complex) matrix represents a complex (resp. quaternionic) linear transformation, and basic aspects of the isomorphism between M(4, R) and the quaternion tensor product. Of these the last is arguably the most vital. Among other things it yields naturally, a surprisingly ubiquitous role for an alternative to the standard representation of the symplectic form in dimension four. Our approach has the benefit of identifying these spin groups as explicit groups of matrices within the same collection of matrices which define $Cl(p, q)$. In other words, we do not work in the algebra of matrices that the collection of even vectors in $Cl(p,q)$ is isomorphic to. This is crucial in some applications and also has the advantage of being didactically simple.

We use ab initio simulations to study the static and dynamic properties of a sodium borosilicate liquid with composition 3Na_2O-B_2O_3-6SiO_2, i.e. a system that is the basis of many glass-forming materials. In particular we focus on the question how boron is embedded into the local structure of the silicate network liquid. From the partial structure factors we conclude that there is a weak nanoscale phase separation between silicon and boron and that the sodium atoms form channel-like structures as they have been found in previous studies of sodo-silicate glass-formers. Our results for the X-ray and neutron structure factor show that this feature is basically unnoticeable in the former but should be visible in the latter as a small peak at small wave-vectors. At high temperatures we find a high concentration of three-fold coordinated boron atoms which decreases rapidly with decreasing T, whereas the number of four-fold coordinated boron atoms increases. Therefore we conclude that at the experimental glass transition temperature most boron atoms will be four-fold coordinated. We show that the transformation of [3]B into [4]B with decreasing T is not just related to the diminution of non-bridging oxygen atoms as claimed in previous studies, but to a restructuration of the silicate matrix. The diffusion constants of the various elements show an Arrhenius behavior and we find that the one for boron has the same value as the one of oxygen and is significantly larger than the one of silicon. This shows that these two network formers have rather different dynamical properties, a result that is also confirmed from the time dependence of the van Hove functions. Finally we show that the coherent intermediate scattering function for the sodium atoms is very different from the incoherent one and that it tracks the one of the matrix atoms.

Despite its great technological importance, the magnetoelectric (ME) couplings in \BF are barely understood. By using a first-principles approach, we uncover the {\it dynamic} ME couplings of the long-range spin-cycloid in BiFeO$_3$. Based on a microscopic Hamiltonian, our first-principles approach disentangles the hidden ME couplings due to spin-current and exchange-striction. Beyond the spin-current polarization governed by the inverse Dzyaloshinskii-Moriya interaction \cite{iDM}, various spin-current polarizations derived from both ferroelectric and antiferrodistortive distortions cooperatively produce the strong non-reciprocal directional dichroism or the asymmetry in the absorption of counter-propagating light in BiFeO$_3$. Our systematic approach can be generally applied to any multiferroic material, laying the foundation for revealing hidden ME couplings on an atomic scale and for exploiting optical ME effects in the next generation of technological devices such as optical diodes.

Despite its great technological importance, the magnetoelectric (ME) couplings in \BF are barely understood. By using a first-principles approach, we uncover the {\it dynamic} ME couplings of the long-range spin-cycloid in BiFeO$_3$. Based on a microscopic Hamiltonian, our first-principles approach disentangles the hidden ME couplings due to spin-current and exchange-striction. Beyond the spin-current polarization governed by the inverse Dzyaloshinskii-Moriya interaction \cite{iDM}, various spin-current polarizations derived from both ferroelectric and antiferrodistortive distortions cooperatively produce the strong non-reciprocal directional dichroism or the asymmetry in the absorption of counter-propagating light in BiFeO$_3$. Our systematic approach can be generally applied to any multiferroic material, laying the foundation for revealing hidden ME couplings on an atomic scale and for exploiting optical ME effects in the next generation of technological devices such as optical diodes.

8 p. ; 21 cm.

This paper is in the public domain in USA. Metadata comes from the CrossRef API, see full record in the source URL below.

This paper is in the public domain in USA. Metadata comes from the CrossRef API, see full record in the source URL below.

"Realistic modeling" is a new direction of electronic structure calculations, where the main emphasis is made on the construction of some effective low-energy model entirely within a first-principle framework. Ideally, it is a model in form, but with all the parameters derived rigorously, on the basis of first-principles electronic structure calculations. The method is especially suit for transition-metal oxides and other strongly correlated systems, whose electronic and magnetic properties are predetermined by the behavior of some limited number of states located near the Fermi level. After reviewing general ideas of realistic modeling, we will illustrate abilities of this approach on the wide series of vanadates RVO3 (R= La, Ce, Pr, Nd, Sm, Gd, Tb, Yb, and Y) with distorted perovskite structure. Particular attention will be paid to computational tools, which can be used for microscopic analysis of different spin and orbital states in the partially filled t2g-band. We will explicitly show how the lifting of the orbital degeneracy by the monoclinic distortion stabilizes C-type antiferromagnetic (AFM) state, which can be further transformed to the G-type AFM state by changing the crystal distortion from monoclinic to orthorhombic one. Two microscopic mechanisms of such a stabilization, associated with the one-electron crystal field and electron correlation interactions, are discussed. The flexibility of the orbital degrees of freedom is analyzed in terms of the magnetic-state dependence of interatomic magnetic interactions.

Includes index

Understanding the unusual friction behavior of hydrogen-free diamond-like carbon films in oxygen atmosphere by first-principles calculations 作者： Wang, LP [Wang, Liping][ 1,3 ] 1 Cui, LC [Cui, Longchen][ 2,3 ] 1 Lu, ZB [Lu, Zhibin][ 3 ] 1 Zhou, H [Zhou, Hui][ 2 ] 1 作者单位： 1. Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China 提交时间： 2017-05-02 摘要: The friction coefficients of diamond and hydrogen-free diamond-like carbon films were reported to be in an intermediate range, from 0.2 to 0.4, in oxygen atmosphere, but the mechanism has not been explored. Herein, by using first-principles calculations, we attempt to fill this gap by providing atomistic insights into the bonding behaviors of oxygen atom(s) at interfaces constructed by two self-mated diamond (001) or (111) surfaces. The effect of the interfacial oxygen coverage on the optimized interfacial structures is highlighted. The results show that if the oxygen coverage is not higher than 0.5, the two surfaces tend to be connected by oxygen atoms by formation of CeOeC bonds, and thus high friction is expected. Otherwise, the two surfaces keep being separated, and thus low friction is expected. The interfacial electron distributions are manifested to underlie the structural optimizations. Insights gained here together with the findings of T. E. Derry et al. concerning oxygen coverage on diamond surfaces contribute to understanding the unusual frictional behavior of hydrogen-free diamond-like carbons in oxygen atmosphere. Abstract: The friction coefficients of diamond and hydrogen-free diamond-like carbon films were reported to be in an intermediate range, from 0.2 to 0.4, in oxygen atmosphere, but the mechanism has not been explored. Herein, by using first-principles calculations, 期刊： CARBON 分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 引用： ChinaXiv:201705.00413 (或此版本 ChinaXiv:201705.00413V1 ) doi:10.12074/201705.00413 CSTR:32003.36.ChinaXiv.201705.00413.V1 推荐引用方式： Wang, LP [Wang, Liping][ 1,3 ],Cui, LC [Cui, Longchen][ 2,3 ],Lu, ZB [Lu, Zhibin][ 3 ],Zhou, H [Zhou, Hui][ 2 ].(2017).Understanding the unusual friction behavior of hydrogen-free diamond-like carbon films in oxygen atmosphere by first-principles calculations.CARBON.[ChinaXiv:201705.00413] 版本历史 [V1] 2017-05-02 12:34:40 ChinaXiv:201705.00413V1 下载全文

On the magnetic structure of [Fe1-xMnx]Pt: A first-principles study 作者： Luo, HB [Luo, Hu-Bin][ 1,2 ] 1 Xia, WX [Xia, Wei-Xing][ 1,2 ] 1 Du, J [Du, Juan][ 1,2 ] 1 Zhang, J [Zhang, Jian][ 1,2 ] 1 Liu, JP [Liu, J. Ping][ 3 ] 1 Yan, A [Yan, Aru][ 1,2 ] 1 作者单位： 1. Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS), Ningbo 315201, P. R. China. 提交时间： 2017-05-02 摘要: This study investigates the composition dependence of magnetic structures of (Fe1−xMnx)Pt using first- principles method. A series of possible magnetic configurations are considered in the calculation to compare the relative stabilities after structural optimization, based on which, together with the com- parison between theoretical and experimental magnetic properties, the results largely support the ex- perimental finding in powders. The experimentally found stability of ferrimagnetic state in films with a wide composition range of x ≤ 0.5 is not fully supported by this study. The composition-dependent magnetic structures are discussed according to the exchange interactions. Abstract: This study investigates the composition dependence of magnetic structures of [Fe1-xMnx]Pt using first-principles method. A series of possible magnetic configurations are considered in the calculation to compare the relative stabilities after structural op Magnetic recording Magnetic structure Phase stability Exchange interaction 期刊： JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS 分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 引用： ChinaXiv:201705.00491 (或此版本 ChinaXiv:201705.00491V1 ) doi:10.12074/201705.00491 CSTR:32003.36.ChinaXiv.201705.00491.V1 推荐引用方式： Luo, HB [Luo, Hu-Bin][ 1,2 ],Xia, WX [Xia, Wei-Xing][ 1,2 ],Du, J [Du, Juan][ 1,2 ],Zhang, J [Zhang, Jian][ 1,2 ],Liu, JP [Liu, J. Ping][ 3 ],Yan, A [Yan, Aru][ 1,2 ].(2017).On the magnetic structure of [Fe1-xMnx]Pt: A first-principles study.JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS.[ChinaXiv:201705.00491] 版本历史 [V1] 2017-05-02 12:34:41 ChinaXiv:201705.00491V1 下载全文

The effect of Nb additive on Te-induced stress corrosion cracking in Ni alloy: a first-principles calculation 作者： LIU Wen-Guan 1,2 HAN Han 1,2 REN Cui-Lan 1,3 YIN Hui-Qin 1,2 HUAI Ping 1,2 ZOU Yang 1,2 XU Hong-Jie 1,2 作者单位： 1. Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China 2. Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Chinese Academy of Sciences, Shanghai 201800, China 3. Key Laboratory of Interfacial Physics and Technology, Chinese Academy of Sciences, Shanghai 201800, China 提交时间： 2023-06-18 摘要: Nb can improve the resistance of Ni-based Hastelloy N alloy to Te-induced intergranular embrittlement. First-principles calculations are performed to research this mechanism by simulating the Ni(111) surface and the 5(012) grain boundary. The calculated adsorption energy suggests that Te atoms prefer diffusing along the grain boundary to forming the surface-reaction layer with Nb on surface of the Ni alloy. First-principles tensile tests show that the Nb segregation can enhance the cohesion of grain boundary. The strong Nb-Ni bonding can prevent the Te migration into the inside of the alloy. According to the Rice-Wang model, the strengthening/embrittling energies of Nb and Te are calculated, along with their mechanical and chemical components. The chemical bonds and electronic structures are analyzed to uncover the physical origin of the different effects of Te and Nb. Our work sheds lights on the effect of Nb additive on the Te-induced intergranular embrittlement in Hastelloy N alloy on the atomic and electronic level. Nb Hastelloy N Te First-principles calculations Stress corrosion cracking Molten salt reactor 期刊： Nuclear Science and Techniques 分类： 核科学技术 >> 裂变堆工程技术 投稿状态： 已在期刊出版 引用： ChinaXiv:202306.00447 (或此版本 ChinaXiv:202306.00447V1 ) DOI:dx.doi.org/10.13538/j.1001-8042/nst.25.050603 CSTR:32003.36.ChinaXiv.202306.00447.V1 推荐引用方式： LIU Wen-Guan,HAN Han,REN Cui-Lan,YIN Hui-Qin,HUAI Ping,ZOU Yang,XU Hong-Jie.(2023).The effect of Nb additive on Te-induced stress corrosion cracking in Ni alloy: a first-principles calculation.Nuclear Science and Techniques.doi:dx.doi.org/10.13538/j.1001-8042/nst.25.050603 版本历史 [V1] 2023-06-18 17:37:40 ChinaXiv:202306.00447V1 下载全文

Mapping the magnetic exchange interactions from model Hamiltonian to density functional theory is a crucial step in multi-scale modeling calculations. Considering the usual magnetic force theorem but with arbitrary rotational angles of the spin moments, a spurious anisotropy in the standard mapping procedure is shown to occur provided by bilinear-like contributions of high order spin interactions. The evaluation of this anisotropy gives a hint on the strength of non-bilinear terms characterizing the system under investigation.

This video is part of the panel "Restoring First Principles" held in Washington, D.C., on February 9, 2012. ABOUT THE AUTHOR: Dr. Stephen P. Halbrook is a Senior Fellow at the Independent Institute. Dr. Halbrook received his J.D. from the Georgetown University Law Center and Ph.D. in social philosophy from Florida State University, and he has taught legal and political philosophy at George Mason University, Howard University, and Tuskegee Institute. His many books also include That Every Man Be Armed: Evolution of a Constitutional Right. Buy the books by Stephen P. Halbrook: "The Founders’ Second Amendment: Origins of the Right to Bear Arms": https://www.independent.org/store/book.asp?id=72 "Gun Control in the Third Reich: Disarming the Jews and 'Enemies of the State'”: https://www.independent.org/store/book.asp?id=106 "Gun Control in Nazi-Occupied France: Tyranny and Resistance": https://www.independent.org/store/book.asp?id=127 "Securing Civil Rights: Freedmen, the Fourteenth Amendment, and the Right to Bear Arms": https://www.independent.org/store/book.asp?id=85 "That Every Man Be Armed: The Evolution of a Constitutional Right": https://www.independent.org/store/book.asp?id=23 INDEPENDENT INSTITUTE ONLINE: FACEBOOK: https://www.facebook.com/independentinst TWITTER: http://twitter.com/independentinst YOUTUBE: https://www.youtube.com/user/independentinstitute WEBSITE: http://www.independent.org

This video is part of the panel "Restoring First Principles" held in Washington, D.C., on February 9, 2012. ABOUT THE AUTHOR: Dr. Stephen P. Halbrook is a Senior Fellow at the Independent Institute. Dr. Halbrook received his J.D. from the Georgetown University Law Center and Ph.D. in social philosophy from Florida State University, and he has taught legal and political philosophy at George Mason University, Howard University, and Tuskegee Institute. His many books also include That Every Man Be Armed: Evolution of a Constitutional Right. Buy the books by Stephen P. Halbrook: "The Founders’ Second Amendment: Origins of the Right to Bear Arms": https://www.independent.org/store/book.asp?id=72 "Gun Control in the Third Reich: Disarming the Jews and 'Enemies of the State'”: https://www.independent.org/store/book.asp?id=106 "Gun Control in Nazi-Occupied France: Tyranny and Resistance": https://www.independent.org/store/book.asp?id=127 "Securing Civil Rights: Freedmen, the Fourteenth Amendment, and the Right to Bear Arms": https://www.independent.org/store/book.asp?id=85 "That Every Man Be Armed: The Evolution of a Constitutional Right": https://www.independent.org/store/book.asp?id=23 INDEPENDENT INSTITUTE ONLINE: FACEBOOK: https://www.facebook.com/independentinst TWITTER: http://twitter.com/independentinst YOUTUBE: https://www.youtube.com/user/independentinstitute WEBSITE: http://www.independent.org

This video is part of the panel "Restoring First Principles" held in Washington, D.C., on February 9, 2012. ABOUT THE AUTHOR: Dr. Stephen P. Halbrook is a Senior Fellow at the Independent Institute. Dr. Halbrook received his J.D. from the Georgetown University Law Center and Ph.D. in social philosophy from Florida State University, and he has taught legal and political philosophy at George Mason University, Howard University, and Tuskegee Institute. His many books also include That Every Man Be Armed: Evolution of a Constitutional Right. Buy the books by Stephen P. Halbrook: "The Founders’ Second Amendment: Origins of the Right to Bear Arms": https://www.independent.org/store/book.asp?id=72 "Gun Control in the Third Reich: Disarming the Jews and 'Enemies of the State'”: https://www.independent.org/store/book.asp?id=106 "Gun Control in Nazi-Occupied France: Tyranny and Resistance": https://www.independent.org/store/book.asp?id=127 "Securing Civil Rights: Freedmen, the Fourteenth Amendment, and the Right to Bear Arms": https://www.independent.org/store/book.asp?id=85 "That Every Man Be Armed: The Evolution of a Constitutional Right": https://www.independent.org/store/book.asp?id=23 INDEPENDENT INSTITUTE ONLINE: FACEBOOK: https://www.facebook.com/independentinst TWITTER: http://twitter.com/independentinst YOUTUBE: https://www.youtube.com/user/independentinstitute WEBSITE: http://www.independent.org