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Simultaneous enantioseparation and simulation studies of atenolol,metoprolol and propranolol on Chiralpak^■IG column using supercritical fluid chromatography

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Journal of Pharmaceutical Analysis 2021年第6期11卷 746-756页

作者： Pranav A.Pandya Priyanka A.Shah Pranav S.Shrivastav Department of Chemistry School of SciencesGujarat UniversityAhmedabad380009India

Enantioseparation of threeβ-blockers,i.e.,atenolol,metoprolol and propranolol,was studied on amylose tris(3-chloro-5-methylphenylcarbamate)immobilized chiral stationary phase using supercritical fluid chromatography(SFC).The effect of organic modifiers(methanol,isopropanol and their mixture),column temperature and back pressure on chiral separation ofβ-blockers was *** chromatographic separation with respect to resolution,retention,and analysis time was achieved using a mixture of CO_(2) and 0.1%isopropyl amine in isopropanol:methanol(50:50,V/V),in 75:25(V/V)*** the optimized conditions,the resolution factors(Rs)and separation factors(a)were greater than3.0 and 1.5,***,with increase in temperature(25-45℃)and pressure(100-150 bars)there was corresponding decrease in retention factors(k),a and ***,a reverse trend(a and Rs)was observed for atenolol with increase in *** thermodynamic data from van’t Hoff plots revealed that the enantioseparation was enthalpy driven for metoprolol and propranolol while entropy driven for *** understand the mechanism of chiral recognition and the elution behavior of the enantiomers,molecular docking studies were *** binding energies obtained from simulation studies were in good agreement with the elution order found experimentally and also with the free energy *** method was validated in the concentration range of 0.5-10μg/m L for all the *** limit of detection and limit of quantitation ranged from 0.126 to 0.137μg/m L and 0.376-0.414μg/m L,*** method was used successfully to analyze these drugs in pharmaceutical preparations.

关键词： Enantioseparation Supercritical fluid chromatography β-blockers Chiralpak^(■)IG column Molecular docking binding energy

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Nuclear structure study of some bubble nuclei in the light mass region using mean field formalism

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Chinese Physics C 2015年第6期39卷 47-53页

作者： Mahesh K.Sharma R.N.Panda Mano j K.Sharma S.K.Patra School of Physics and Material Sciences Thapar University

We study the structural properties of some light mass nuclei using two different formalisms(i) a recently developed simple effective interaction in the frame work of microscopic non-relativistic Hartree-Fock method and(ii)the well-known relativistic mean field approach with NL3 parameter set. The bulk properties like binding energy, root mean square radii and quadrupole deformation parameter are estimated and compared with the available experimental data. The predicted results of both the formalisms are well comparable with the experimental observations. The analysis of density profiles of these light mass nuclei suggest that22 O,23F,34 Si and46Ar have bubble like structure.

关键词： binding energy charge radius relativistic mean field simple effective interaction non-relativistic mean fields

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Toward precision mass measurements of neutron-rich nuclei relevant to r-process nucleosynthesis

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Frontiers of physics 2015年第4期10卷 1-25页

作者： B. H. Sun Yu. A. Litvinov I. Tanihata Y. H. Zhang School of Physics and Nuclear energy Engineering Beihang University Beijing 100191 China International Research Center for Nuclei and Particles in the Cosmos Beijing 100191 China Key Laboratory of High Precision Nuclear Spectroscopy and Center for Nuclear Matter Science Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China GSI Helmholtzzentrum fiir Schwerionenforschung Planckstrafle 1 64291 Darmstadt Germany

The open question of where, when, and how the heavy elements beyond iron enrich our Universe has triggered a new era in nuclear physics studies. Of all the relevant nuclear physics inputs, the mass of very neutron-rich nuclides is a key quantity for revealing the origin of heavy elements beyond iron. Although the precise determination of this property is a great challenge, enormous progress has been made in recent decades, and it has contributed significantly to both nuclear structure and astrophysical nucleosynthesis studies. In this review, we first survey our present knowledge of the nuclear mass surface, emphasizing the importance of nuclear mass precision in r-process calculations. We then discuss recent progress in various methods of nuclear mass measurement with a few selected examples. For each method, we focus on recent breakthroughs and discuss possible ways of improving the weighing of r-process nuclides.

关键词： binding energy r-process nucleosynthesis nuclear mass spectrometry

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A Density Functional Investigation of Fluorinated Silicon Clusters

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Chinese Journal of Chemistry 2011年第4期29卷 735-740页

作者：王宏武林 College of Mathematics Physics and Information Engineering Zhejiang Normal University Jinhua Zhejiang 321004 China

Density functional calculations have been carried out on a series of fluorinated empty cages XnFn （n=2-20） with X=Si, Ge, and Sn. It indicates that the fullerene-like cage structure with pentagons turns out to be the most stable with n increasing, and the stability of the XnFn isomers increases with the number of five-membered rings. The HOMO-LUMO gap for Ge （n=6, 10） cages is found to be even larger than the values for Si cages, though in bulk Ge has a smaller band gap than Si. Moreover, calculation of the Gibbs free energy of oligomerization reaction of SiF→1/n （SiF）n showed that this reaction is exothermic even at 900 K, indicating the favorability of their formation from the SiF monomer.

关键词： density functional theory stability binding energy HOMO-LUMO gap

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A Reliability Analysis of Calculated Results for Odd-Even and Odd-Odd Nuclei in Relativistic Mean-Field Theory

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Communications in Theoretical Physics 2006年第1X期46卷 113-118页

作者： DING Bin-Gang ZHANG Da-Li LU Ding-Hui School of Science Huzhou Teachers College Huzhou 313000 China Institute of Modern Physics Zhejiang University Hangzhou 310027 China

We calculate the binding energies of Ni, Cu, Xe, Cs, Pt, Au, Np, Pu isotope chains using two interaction parameter sets NL-3 and NL-Z, and compared the relative errors of the even-even nuclei with those of odd-even nuclei and odd-odd nuclei. We find that the errors of binding energy of odd-even and odd-odd nuclei are not bigger than the one of even-even nuclei. The result shows that comparing with even-even nuclei, there is no systematic error and approximation in the calculations of the binding energy of odd-even and odd-odd nuclei with relativistic mean-field theory. In addition, the result is explained theoretically.

关键词： relativistic mean-field theory binding energy even-even nuclei odd-even nuclei odd-odd nuclei

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Revisiting the island of hexadecapoledeformation nuclei in the A≈150 mass region:focusing on the model application to nuclear shapes and masses

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Communications in Theoretical Physics 2024年第2期76卷 74-88页

作者： Xiao-Yang Wei Hua-Lei Wang Zhen-Zhen Zhang Min-Liang Liu School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China Key Laboratory of High Precision Nuclear Spectroscopy Institute of Modern PhysicsChinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

Based on the potential-energy-surface calculation,the impact of different deformation degrees of freedom on a single-particle structure and binding energies in nuclei around^(152)Nd,located on one of the hexadecapole-deformation islands,is analyzed in a multi-dimensional deformation *** energy maps,curves and tables are presented to indicate nuclear *** calculated equilibrium deformations and binding energies with different potential parameters are compared with experimental data and other *** is found that the inclusion of the hexadecapole deformations,especially the axial one,can improve the theoretical description of both nuclear shapes and *** addition,our calculated potential-energy curve shows that a critical deformation-point,β_(2)≈0.4,exists—the triaxial(hexadecapole)deformation effect can be neglectable but the hexadecapole(triaxial)one plays an important role before(after)such a critical point.

关键词： hexadecapole deformation binding energy potential-energy-surface calculation nuclear property

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Interactions of Heavy Metal Ions with Paddy Soils as Inferred from Wien Effect Measurements in Dilute Suspensions

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Pedosphere 2006年第6期16卷 718-725页

作者： JIANG Jun LI Cheng-Bao ZHAO An-Zhen XU Ren-Kou WANG Yu-Jun S. P. FRIEDMAN Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 China Institute of Soil Water and Environmental Sciences Agricultural Research Organization Voleani Center Bet Dagan 50250 Israel

Interactions of three heavy metal ions, Cu^2＋, Cd^2＋, and Pb^2＋, and, for comparison, Na^＋ with electrodialytic clay fractions （less than 2μm in diameter） of four paddy soils as well as a yellow-brown soil as a control soil were evaluated based on measurements of the Wien effect in dilute suspensions with a clay concentration of 10 g kg^-1 in four nitrate solutions of 2 × 10^-4/z mol L^-1, where z is the cation valence, and a nitric acid solution of 3 × 10^-5 mol L^-1, Field strengths ranging from 15 to 230 kV cm^-1 were applied for measuring the electrical conductivities （ECs） of the suspensions. The mean free binding energies between the various cations and all of the soils determined from exchange equilibrium increased in the order： Na^＋〈 Cd^2＋〈 Cu^2＋〈 Pb^2＋. In general, the ECs of the suspensions in the sodium nitrate solution were smaller than those of the suspensions in the heavy metal solutions because of the lower electrophoretic mobility of sodium compared to the divalent cations. In terms of relative electrical conductivity-field strength relationships, relative electrical conductivity （REC） of suspensions containing various cations at field strengths larger than about 50 kV cm^-1 were in the descending order： Na^＋〉 Cu^2＋〉 Cd^2＋〉 Pb^2＋ for all tested soils. A characteristic parameter of the REC-field strength curves, AREC200, REC at a field strength of 200 kV cm^-1 minus that at the local minimum of the concave segment of the REC-field strength curves, characterized the strength of adsorption of the cations stripped off by the applied strong electrical field, and for all soils the values of AREC200 were generally in the order： Na^＋〈 Cu^2＋ ≤ Cd^2＋〈 Pb^2＋.

关键词： binding energy electrical conductivity field strength heavy metal ions paddy soils

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Geometry,Electronic Properties and Magnetism of Be_mO_n(m+n=3,4,5) Clusters

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Chinese Journal of Structural Chemistry 2015年第9期34卷 1451-1457页

作者：黎康宁杨传路王美山马晓光 School of Physics and Optoelectronic Engineering Ludong University

Thirty BemOn （m＋n = 3, 4, 5） stable isomers are obtained with optimization and frequency analysis based on density functional theory and all-electron numerical basis set. The hundreds of initial geometries are built using the ＂binomial＂ scheme. The binding energies, the energy gaps between the highest occupied molecular orbital and the lowest unoccupied molecular orbital, and the magnetic moments of all stable isomers are calculated and analyzed. It is found that the Be-O bonds play an important role in the stability of the clusters, and the total magnetic moments of the isomers mainly depend on the magnetic moment of O atoms, Be atoms and the arrangement of magnetic moments of all atoms.

关键词： BemOn clusters Be-O bond binding energy magnetism

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Rare earth effect of yttrium on formation and property of Cr2O3 oxide film formed on Co-Cr binary alloy

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Progress in Natural Science:Materials International 2006年第1期16卷 72-77页

作者： FELIX A. Congrado AROYAVE M. Hayara College of Materials Science and Engineering National University of Antiuquia Medellin 23715Colombia

The isothermal oxidizing kinetics of Co-40Cr alloy and its yttrium ion-implanted samples were studied at 1000 ℃ in air by thermal-gravity analysis (TGA). Scanning electronic microscopy (SEM) was used to examine the Cr2O3 oxide film's morphology after oxidation. Secondary ion mass spectrum (SIMS) method was used to examine the binding energy change of chromium caused by Y-doping and its influence on formation of Cr2O3 film. Acoustic emission (AE) method was used in situ to monitor the cracking and spalling of oxide films formed on both samples during oxidizing and subsequent air-cooling stages. Theoretical model simulating the film fracture process was proposed to analyze the acoustic emission spectrum both on time domain and on AE-event number domain. It is found that yttrium ion-implantation can remarkably reduce the isothermal oxidizing rate of Co-40Cr and improve the anti-cracking and anti-spalling properties of Cr2O3 oxide film. Reasons for the improvement are mainly that the implanted yttrium can reduce the grain size of Cr2O3 oxide, increase the high temperature plasticity of oxide film, and remarkably reduce the number and size of Cr2O3/Co-40Cr interfacial defects.

关键词： interface binding energy acoustic emission oxidation yttrium.

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Effect of Wigner energy on the symmetry energy coefficient in nuclei

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Chinese Physics C 2016年第9期40卷 41-46页

作者：田俊龙崔海涛高腾王宁 School of Physics and Electrical Engineering Anyang Normal University Department of Physics Guangxi Normal University State Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences

The nuclear symmetry energy coefficient（including the coefficient asym^（4） of the I^4 term） of finite nuclei is extracted by using the differences of available experimental binding energies of isobaric *** is found that the extracted symmetry energy coefficient asym^＊（A,I） decreases with increasing isospin asymmetry I,which is mainly caused by Wigner correction,since esym^＊ is the summation of the traditional symmetry energy esym and the Wigner energy *** obtain the optimal values J = 30.25±0.10 MeV,ass=56.18±1.25 MeV,asym^（4） = 8.33±1.21 MeV and the Wigner parameter x= 2.38 ±0.12 through a polynomial fit to 2240 measured binding energies for nuclei with20 ≤ A ≤ 261 with an rms deviation of 23.42 *** also find that the volume symmetry coefficient J≌ 30 MeV is insensitive to the value x,whereas the surface symmetry coefficient ass and the coefficient asym^（4） are very sensitive to the value of x in the range 1≤x≤*** contribution of the asym^（4） term increases rapidly with increasing isospin asymmetry *** very neutron-rich nuclei,the contribution of the asym^（4） term will play an important role.

关键词： symmetry energy Wigner energy binding energy isobaric nuclei

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