We use sets of de Broglie-Bohm trajectories to describe the quantum correlation effects which take place between the electrons in helium atom due to exchange and Coulomb interactions. A short-range screening of the Coulomb potential is used to modify the repulsion between the same spin electrons in physical space in order to comply with Pauli's exclusion principle. By calculating the electron-pair density for orthohelium, we found that the shape of the exchange hole can be controlled uniquely by a simple screening parameter. For parahelium the interelectronic distance, hence the Coulomb hole, results from the combined action of the Coulomb repulsion and the nonlocal quantum correlations. In this way, a robust and self-interaction-free approach is presented to find both the ground state and the time evolution of nonrelativistic quantum systems.
{"title":"Electron-Pair Densities with Time-Dependent Quantum Monte Carlo","authors":"I. Christov","doi":"10.1155/2013/424570","DOIUrl":"https://doi.org/10.1155/2013/424570","url":null,"abstract":"We use sets of de Broglie-Bohm trajectories to describe the quantum correlation effects which take place between the electrons in helium atom due to exchange and Coulomb interactions. A short-range screening of the Coulomb potential is used to modify the repulsion between the same spin electrons in physical space in order to comply with Pauli's exclusion principle. By calculating the electron-pair density for orthohelium, we found that the shape of the exchange hole can be controlled uniquely by a simple screening parameter. For parahelium the interelectronic distance, hence the Coulomb hole, results from the combined action of the Coulomb repulsion and the nonlocal quantum correlations. In this way, a robust and self-interaction-free approach is presented to find both the ground state and the time evolution of nonrelativistic quantum systems.","PeriodicalId":15106,"journal":{"name":"Journal of Atomic and Molecular Physics","volume":"22 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2013-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81163132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Industrial applications need regular testing for the lifetime, movement, strength, and performance of manufacturing machines during production process. Since speckle photography is a simple economic technique, it is used in investigating object response under mechanical and thermal effects depending on the movement of the speckle patterns with respect to the deformation strength and direction. In the present work, the cross-correlation technique is used to analyze the speckle patterns by iterative method to define both values and directions of rigid body translation and expansion. In order to check the accuracy of the cross-correlation technique, the results are compared with the displacement values given by analyzing the Young's interference fringes resulted from the Fourier transformation of the speckle patterns. This noncontact technique is found to be accurate and informative depending on the stability and sensitivity of the optical system. This method of measurement is an effective tool in studying the hard cases of objects and machines under various effects.
{"title":"Speckle Cross-Correlation Method in Measuring Fine Surface Displacements","authors":"M. Bahrawi, N. Farid, M. Abdel-hady","doi":"10.1155/2012/976376","DOIUrl":"https://doi.org/10.1155/2012/976376","url":null,"abstract":"Industrial applications need regular testing for the lifetime, movement, strength, and performance of manufacturing machines during production process. Since speckle photography is a simple economic technique, it is used in investigating object response under mechanical and thermal effects depending on the movement of the speckle patterns with respect to the deformation strength and direction. In the present work, the cross-correlation technique is used to analyze the speckle patterns by iterative method to define both values and directions of rigid body translation and expansion. In order to check the accuracy of the cross-correlation technique, the results are compared with the displacement values given by analyzing the Young's interference fringes resulted from the Fourier transformation of the speckle patterns. This noncontact technique is found to be accurate and informative depending on the stability and sensitivity of the optical system. This method of measurement is an effective tool in studying the hard cases of objects and machines under various effects.","PeriodicalId":15106,"journal":{"name":"Journal of Atomic and Molecular Physics","volume":"51 2","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2012-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2012/976376","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72466672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The refractive indices of the cholesteric liquid crystal solution were measured using multiwavelength (visible range) refractometer for three different wavelengths. Measurements were made at different temperatures for various concentrations of the solution, mixing CLC in a soluble solvent. Vuks equation describes the wavelength and temperature dependence of refractive indices of anisotropic crystalline materials. We have used a simplified version of Vuks equation relating only to macroscopic indices and verified its validity for five-different-concentration solution at various temperatures. The result is also used to obtain molecular polarizabilities and temperature dependent material constants of our sample.
{"title":"Experimental Verification of Vuks Equation Using Hollow Prism Refractometer","authors":"A. Kanwar, P. Yadav","doi":"10.1155/2012/689831","DOIUrl":"https://doi.org/10.1155/2012/689831","url":null,"abstract":"The refractive indices of the cholesteric liquid crystal solution were measured using multiwavelength (visible range) refractometer for three different wavelengths. Measurements were made at different temperatures for various concentrations of the solution, mixing CLC in a soluble solvent. Vuks equation describes the wavelength and temperature dependence of refractive indices of anisotropic crystalline materials. We have used a simplified version of Vuks equation relating only to macroscopic indices and verified its validity for five-different-concentration solution at various temperatures. The result is also used to obtain molecular polarizabilities and temperature dependent material constants of our sample.","PeriodicalId":15106,"journal":{"name":"Journal of Atomic and Molecular Physics","volume":"8 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2012-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91383243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Previously (Chen et al., 2004), it was shown that dielectric cylinder can form focal spots with small diameters and long depth. This type of focal spot was called photonic nanojet. In this paper, it was shown that dielectric cylinder of radius 595 nm (1.12 of wavelength) forms near the surface a photonic nanojet with diameter equal to 0.31 of wavelength and depth of focus equal to 0.57 of wavelength. Adding truncated concentric rings with radiuses equal to radiuses of zone plate to the cylinder increases the depth of focus to 1.18 of the wavelength. The diameter and intensity of focal spot near the cylinder surface remain unchanged.
先前(Chen et al.， 2004)的研究表明，介质圆柱体可以形成直径小、深度长的焦斑。这种类型的焦斑被称为光子纳米射流。结果表明，半径为595 nm(波长1.12)的介质圆柱体在表面附近形成了直径为0.31波长、聚焦深度为0.57波长的光子纳米射流。在圆柱体上加入半径等于带片半径的截断同心圆，使聚焦深度增加到波长的1.18。柱面附近焦斑的直径和强度保持不变。
{"title":"Elongated Photonic Nanojet from Truncated Cylindrical Zone Plate","authors":"S. Stafeev, V. Kotlyar","doi":"10.1155/2012/123872","DOIUrl":"https://doi.org/10.1155/2012/123872","url":null,"abstract":"Previously (Chen et al., 2004), it was shown that dielectric cylinder can form focal spots with small diameters and long depth. This type of focal spot was called photonic nanojet. In this paper, it was shown that dielectric cylinder of radius 595 nm (1.12 of wavelength) forms near the surface a photonic nanojet with diameter equal to 0.31 of wavelength and depth of focus equal to 0.57 of wavelength. Adding truncated concentric rings with radiuses equal to radiuses of zone plate to the cylinder increases the depth of focus to 1.18 of the wavelength. The diameter and intensity of focal spot near the cylinder surface remain unchanged.","PeriodicalId":15106,"journal":{"name":"Journal of Atomic and Molecular Physics","volume":"162 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2012-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72840785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Christian, E. McCoy, G. S. McDonald, J. Sánchez-Curto, P. Chamorro-Posada
We consider arbitrary angle interactions between spatial solitons and the planar boundary between two optical materials with a single power-law nonlinear refractive index. Extensive analysis has uncovered a wide range of new qualitative phenomena in non-Kerr regimes. A universal Helmholtz-Snell law describing soliton refraction is derived using exact solutions to the governing equation as a nonlinear basis. New predictions are tested through exhaustive computations, which have uncovered substantially enhanced Goos-Hanchen shifts at some non-Kerr interfaces. Helmholtz nonlinear surface waves are analyzed theoretically, and their stability properties are investigated numerically for the first time. Interactions between surface waves and obliquely incident solitons are also considered. Novel solution behaviours have been uncovered, which depend upon a complex interplay between incidence angle, medium mismatch parameters, and the power-law nonlinearity exponent.
{"title":"Helmholtz Bright Spatial Solitons and Surface Waves at Power-Law Optical Interfaces","authors":"J. Christian, E. McCoy, G. S. McDonald, J. Sánchez-Curto, P. Chamorro-Posada","doi":"10.1155/2012/137967","DOIUrl":"https://doi.org/10.1155/2012/137967","url":null,"abstract":"We consider arbitrary angle interactions between spatial solitons and the planar boundary between two optical materials with a single power-law nonlinear refractive index. Extensive analysis has uncovered a wide range of new qualitative phenomena in non-Kerr regimes. A universal Helmholtz-Snell law describing soliton refraction is derived using exact solutions to the governing equation as a nonlinear basis. New predictions are tested through exhaustive computations, which have uncovered substantially enhanced Goos-Hanchen shifts at some non-Kerr interfaces. Helmholtz nonlinear surface waves are analyzed theoretically, and their stability properties are investigated numerically for the first time. Interactions between surface waves and obliquely incident solitons are also considered. Novel solution behaviours have been uncovered, which depend upon a complex interplay between incidence angle, medium mismatch parameters, and the power-law nonlinearity exponent.","PeriodicalId":15106,"journal":{"name":"Journal of Atomic and Molecular Physics","volume":"117 1","pages":"1-21"},"PeriodicalIF":0.0,"publicationDate":"2012-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90488620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Polarized IR spectra of 2-furanacetic acid and of 2-furanacrylic acid crystals were measured at 293 K and 77 K in the 𝑣O−H and 𝑣O−H band frequency ranges. The corresponding spectra of the two individual systems strongly differ, one from the other, by the corresponding band shapes as well as by the temperature effect characterizing the bands. The crystal spectral properties remain in a close relation with the electronic structure of the two different molecular systems. We show that a vibronic coupling mechanism involving the hydrogen bond protons and the electrons on the π-electronic systems in the molecules determines the way in which the vibrational exciton coupling between the hydrogen bonds in the carboxylic acid dimers occurs. A strong coupling in 2-furanacrylic acid dimers prefers a “tail-to-head-” type Davydov coupling widespread by the π-electrons. A weak through-space coupling in 2-furanacetic acid dimers is responsible for a “side-to-side-” type coupling. The relative contribution of each exciton coupling mechanism in the dimer spectra generation is temperature and the molecular electronic structure dependent. This explains the observed difference in the temperature-induced evolution of the compared spectra.
{"title":"Temperature and H/D Isotopic Effects in the IR Spectra of the Hydrogen Bond in Solid-State 2-Furanacetic Acid and 2-Furanacrylic Acid","authors":"H. Flakus, Anna Jarczyk-Jedryka","doi":"10.1155/2012/125471","DOIUrl":"https://doi.org/10.1155/2012/125471","url":null,"abstract":"Polarized IR spectra of 2-furanacetic acid and of 2-furanacrylic acid crystals were measured at 293 K and 77 K in the 𝑣O−H and 𝑣O−H band frequency ranges. The corresponding spectra of the two individual systems strongly differ, one from the other, by the corresponding band shapes as well as by the temperature effect characterizing the bands. The crystal spectral properties remain in a close relation with the electronic structure of the two different molecular systems. We show that a vibronic coupling mechanism involving the hydrogen bond protons and the electrons on the π-electronic systems in the molecules determines the way in which the vibrational exciton coupling between the hydrogen bonds in the carboxylic acid dimers occurs. A strong coupling in 2-furanacrylic acid dimers prefers a “tail-to-head-” type Davydov coupling widespread by the π-electrons. A weak through-space coupling in 2-furanacetic acid dimers is responsible for a “side-to-side-” type coupling. The relative contribution of each exciton coupling mechanism in the dimer spectra generation is temperature and the molecular electronic structure dependent. This explains the observed difference in the temperature-induced evolution of the compared spectra.","PeriodicalId":15106,"journal":{"name":"Journal of Atomic and Molecular Physics","volume":"35 1","pages":"1-17"},"PeriodicalIF":0.0,"publicationDate":"2012-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81930887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I present a time-dependent density functional study of the 20 low-lying excited states as well the ground states of the zinc dimer Zn2, analyze its spectrum obtained from all electrons calculations performed using time-depended density functional with a relativistic 4-component and relativistic spin-free Hamiltonian as implemented in Dirac-Package, and show a comparison of the results obtained from different well-known and newly developed density functional approximations, a comparison with the literature and experimental values as far as available. The results are very encouraging, especially for the lowest excited states of this dimer. However, the results show that long-range corrected functionals such as CAMB3LYP gives the correct asymptotic behavior for the higher states, and for which the best result is obtained. A comparable result is obtained from PBE0 functional. Spin-free Hamiltonian is shown to be very efficient for relativistic systems such as Zn2.
{"title":"Relativistic Time-Dependent Density Functional Theory and Excited States Calculations for the Zinc Dimer","authors":"O. Kullie","doi":"10.1155/2012/361947","DOIUrl":"https://doi.org/10.1155/2012/361947","url":null,"abstract":"I present a time-dependent density functional study of the 20 low-lying excited states as well the ground states of the zinc dimer Zn2, analyze its spectrum obtained from all electrons calculations performed using time-depended density functional with a relativistic 4-component and relativistic spin-free Hamiltonian as implemented in Dirac-Package, and show a comparison of the results obtained from different well-known and newly developed density functional approximations, a comparison with the literature and experimental values as far as available. The results are very encouraging, especially for the lowest excited states of this dimer. However, the results show that long-range corrected functionals such as CAMB3LYP gives the correct asymptotic behavior for the higher states, and for which the best result is obtained. A comparable result is obtained from PBE0 functional. Spin-free Hamiltonian is shown to be very efficient for relativistic systems such as Zn2.","PeriodicalId":15106,"journal":{"name":"Journal of Atomic and Molecular Physics","volume":"58 1","pages":"1-16"},"PeriodicalIF":0.0,"publicationDate":"2012-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78853326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Gorski, S. Gawinkowski, R. Luboradzki, M. Tkacz, R. Thummel, J. Waluk
Two forms of cyclic, doubly hydrogen-bonded dimers are discovered for crystalline 1H-pyrrolo[3,2-h]quinoline, a bifunctional molecule possessing both hydrogen bond donor and acceptor groups. One of the forms is planar, the other is twisted. Analysis of IR and Raman spectra, combined with DFT calculations, allows one to assign the observed vibrations and to single out vibrational transitions which can serve as markers of hydrogen bond formation and dimer structure. Raman spectra measured for samples submitted to high pressure indicate a transition from the planar towards the twisted structure. Formation of intermolecular hydrogen bonds leads to a large increase of the Raman intensity of the NH stretching band: it can be readily observed for the dimer, but is absent in the monomer spectrum.
{"title":"Polymorphism, Hydrogen Bond Properties, and Vibrational Structure of 1H-Pyrrolo[3,2-h]Quinoline Dimers","authors":"A. Gorski, S. Gawinkowski, R. Luboradzki, M. Tkacz, R. Thummel, J. Waluk","doi":"10.1155/2012/236793","DOIUrl":"https://doi.org/10.1155/2012/236793","url":null,"abstract":"Two forms of cyclic, doubly hydrogen-bonded dimers are discovered for crystalline 1H-pyrrolo[3,2-h]quinoline, a bifunctional molecule possessing both hydrogen bond donor and acceptor groups. One of the forms is planar, the other is twisted. Analysis of IR and Raman spectra, combined with DFT calculations, allows one to assign the observed vibrations and to single out vibrational transitions which can serve as markers of hydrogen bond formation and dimer structure. Raman spectra measured for samples submitted to high pressure indicate a transition from the planar towards the twisted structure. Formation of intermolecular hydrogen bonds leads to a large increase of the Raman intensity of the NH stretching band: it can be readily observed for the dimer, but is absent in the monomer spectrum.","PeriodicalId":15106,"journal":{"name":"Journal of Atomic and Molecular Physics","volume":"1 1","pages":"1-11"},"PeriodicalIF":0.0,"publicationDate":"2012-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83112055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Implantable wireless devices may allow localized real-time biomedical treating and monitoring. However, such devices require a power source, which ideally, should be self-powered and not battery dependent. In this paper, we present a novel self-powered light therapeutic device which is designed to implement blood irradiation therapy. This device is self-powered by a miniaturized turbine-based generator which uses hydraulic flow energy as its power source. The research presented in this paper may become the first step towards a new type of biomedical self-operational micromechanical devices deployed for biomedical applications.
{"title":"A Self-Powered Medical Device for Blood Irradiation Therapy","authors":"Avigail D. Amsel, A. Rudnitsky, Z. Zalevsky","doi":"10.1155/2012/963187","DOIUrl":"https://doi.org/10.1155/2012/963187","url":null,"abstract":"Implantable wireless devices may allow localized real-time biomedical treating and monitoring. However, such devices require a power source, which ideally, should be self-powered and not battery dependent. In this paper, we present a novel self-powered light therapeutic device which is designed to implement blood irradiation therapy. This device is self-powered by a miniaturized turbine-based generator which uses hydraulic flow energy as its power source. The research presented in this paper may become the first step towards a new type of biomedical self-operational micromechanical devices deployed for biomedical applications.","PeriodicalId":15106,"journal":{"name":"Journal of Atomic and Molecular Physics","volume":"36 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2012-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79565249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Sobczyk, B. Czarnik-Matusewicz, M. Rospenk, M. Obrzud
The aim of the present paper is an analysis of the hydrogen bond properties for the acid-base systems depending on the ability to the proton transfer in the formulation of the Bronsted approach. After definition of the proton transfer equilibrium expressed by using the equation log𝐾PT=𝜉Δ𝑝𝐾𝑁, various examples of different physical properties, such as dipole moments, IR spectra, and nuclear magnetic resonances, are presented which correlate with the Δ𝑝𝐾𝑁 value. In such a way, a critical state of hydrogen bonding can be defined that corresponds to the potential of the proton motion for either single minimum or double minimum with low barrier. A particular attention in this paper found electronic spectra which have not been analysed so far and the quantitative analysis of the vibrational polarizability which can reach very high values of the order of electronic polarizability.
{"title":"Proton Transfer Equilibria and Critical Behavior of H-Bonding","authors":"L. Sobczyk, B. Czarnik-Matusewicz, M. Rospenk, M. Obrzud","doi":"10.1155/2012/217932","DOIUrl":"https://doi.org/10.1155/2012/217932","url":null,"abstract":"The aim of the present paper is an analysis of the hydrogen bond properties for the acid-base systems depending on the ability to the proton transfer in the formulation of the Bronsted approach. After definition of the proton transfer equilibrium expressed by using the equation log𝐾PT=𝜉Δ𝑝𝐾𝑁, various examples of different physical properties, such as dipole moments, IR spectra, and nuclear magnetic resonances, are presented which correlate with the Δ𝑝𝐾𝑁 value. In such a way, a critical state of hydrogen bonding can be defined that corresponds to the potential of the proton motion for either single minimum or double minimum with low barrier. A particular attention in this paper found electronic spectra which have not been analysed so far and the quantitative analysis of the vibrational polarizability which can reach very high values of the order of electronic polarizability.","PeriodicalId":15106,"journal":{"name":"Journal of Atomic and Molecular Physics","volume":"1 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2012-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89723703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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