Solutions of the Schr?dinger equation in the tridiagonal representation with the noncentral electric dipole plus a novel angle-dependent component

A noncentral ring-shaped potential is proposed in which the noncentral electric dipole and a novel angle-dependent component are included, the radial part is selected as the Coulomb potential or the harmonic oscillator potential. The exact solution of the Schr?dinger equation with this potential is investigated by working in a complete square integrable basis that supports a tridiagonal matrix representation of the wave operator. The resulting three-term recursion relation for the expansion coefficients of the wavefunctions (both angular and radial) are presented. The angular/radial wavefunction is written in terms of the Jacobi/Laguerre polynomials. The discrete spectrum of the bound states is obtained by diagonalization of the radial recursion relation.     

Simultaneous Determination of Zoalene and Its Metabolite in Chicken Muscle and Liver by SPE and UPLC�CMS-MS

This paper presents an analytical method for the simultaneous determination of zoalene and its metabolite 3-amino-5-nitro-o-toluamide (3-ANOT) in chicken muscle and liver by solid phase extraction and UPLC?CMS-MS operated in the positive and negative ionization switching mode. Samples were extracted with phosphate buffer solution and purified with OASIS^? HLB cartridge after pH adjustment. The determination was carried out using UPLC?CMS-MS on a Waters Acquity BEH C₁₈ column with 0.1% formic acid in water/acetonitrile as mobile phase with gradient elution. The linearity of the analytical response across the studied range of concentrations (2.0?C1,000 ??g L^?1) was excellent, obtaining correlation coefficients higher than 0.999. Matrix effects had been investigated for zoalene and 3-ANOT. Recovery studies were carried out on spiked chicken muscle and liver blank samples, at four concentration levels (50, 1,500, 3,000, and 4,500 ??g kg^?1 for chicken muscle and 50, 3,000, 6,000, and 9,000 ??g kg^?1 for chicken liver) performing six replicates at each level. Mean recoveries of 77.9?C94.2% with CVs of 3.2?C8.7% were obtained. The method demonstrated to be suitable for the simultaneous determination of zoalene and 3-ANOT in chicken tissues.     

Exact solutions of a new Coulomb ring-shaped potential

A new Coulomb ring-shaped potential is proposed, which results from adding a potential proportional to(cos θ/r ² sin² θ)to a Coulomb potential. The Schrödinger equation with this new model potential is separated into angular and radial components. The exactly wavefunctions and the spectrum equation for bound state are presented by the standard approach.     

Simultaneous determination of clenbuterol, salbutamol and ractopamine in milk by reversed-phase liquid chromatography tandem mass spectrometry with isotope dilution

A simple, sensitive and reliable analytical method was developed for the simultaneous determination of clenbuterol (CLB), salbutamol (SAL) and ractopamine (RAC) in milk by ultra high performance liquid chromatography–positive electrospray ionization tandem mass spectrometry (UHPLC–ESI-MS/MS) with isotope dilution. Samples were directly purified through HLB cartridge. Then the eluate was dried under nitrogen and residues were redissolved in mobile phase. Samples were analyzed by LC–MS/MS on an Acquity UPLC^® BEH C₁₈ column with gradient elution. The samples were quantified using clenbuterol-D₉, salbutamol-D₃ and ractopamine-D₆ as internal standards. The proposed method was validated according to the European Commission Decision 2002/657/EC determining specificity, decision limit (CCα), detection capability (CCβ), recovery, precision, linearity, robustness and stability. CCα values were 0.054, 0.006 and 0.008 μg/kg for CLB, SAL and RAC, respectively. CCβ values were 0.058, 0.007 and 0.009 μg/kg for CLB, SAL and RAC, respectively. The mean recoveries, repeatability (expressed as coefficient of variation, CV_r), and reproducibility (CV_R) varied from 95.8 to 106.2%, from 3.60 to 6.44% (CVr), and from 4.77 to 7.53% (CV_R), respectively. The method is demonstrated to be suitable for the determination of clenbuterol, salbutamol and ractopamine in milk. The total time required for the analysis of one sample, including sample preparation, was about 45 min.     

Rapid determination of fumonisins B1 and B2 in corn by liquid chromatography-tandem mass spectrometry with ultrasonic extraction

A simple, sensitive, and reliable analytical method is developed for the rapid determination of fumonisin B(1) and fumonisin B(2) in corn by high-performance liquid chromatography-positive electrospray ionization tandem mass spectrometry (LC-ESI-MS-MS). Fumonisin B(1) and fumonisin B(2) are extracted from corn with methanol-water (3:1, v/v) by means of ultrasonic extraction, and directly injected into an LC-MS-MS system after centrifugation. Fumonisin B(1) and fumonisin B(2) are separated on a Zorbax Eclipse XDB-C(18) column with a solution of methanol-water-formic acid as the mobile phase. The method is validated with respect to linearity, accuracy, precision, specificity, and stability. Moreover, the method was applied to real samples and demonstrated to be suitable for the determination of fumonisin B(1) and fumonisin B(2) in corn. The total time required for the analysis of one sample was ~30 min.     

在Si-Ge晶体外延生长中的RHEED花样研究

在晶体衍射理论基础上,利用运动学理论解释了反射式高能电子衍射（reflection high energy electron diffraction, RHEED）在Si-Ge晶体外延生长过程中不同阶段出现的花样．尤其研究了晶体岛状生长之后出现的RHHED透射式衍射花样,并给出了相应的解释．解释了硅锗外延生长过程中的多晶环图案和孪晶衍射图案的含义,并给出各个生长阶段演化的工艺条件． 关键词： 硅锗外延生长 反射式高能电子衍射 表面重构 透射式衍射花样     

Simultaneous Determination of Zoalene and Its Metabolite in Chicken Muscle and Liver by SPE and UPLC–MS-MS

This paper presents an analytical method for the simultaneous determination of zoalene and its metabolite 3-amino-5-nitro-o-toluamide (3-ANOT) in chicken muscle and liver by solid phase extraction and UPLC–MS-MS operated in the positive and negative ionization switching mode. Samples were extracted with phosphate buffer solution and purified with OASIS^™ HLB cartridge after pH adjustment. The determination was carried out using UPLC–MS-MS on a Waters Acquity BEH C₁₈ column with 0.1% formic acid in water/acetonitrile as mobile phase with gradient elution. The linearity of the analytical response across the studied range of concentrations (2.0–1,000 μg L⁻¹) was excellent, obtaining correlation coefficients higher than 0.999. Matrix effects had been investigated for zoalene and 3-ANOT. Recovery studies were carried out on spiked chicken muscle and liver blank samples, at four concentration levels (50, 1,500, 3,000, and 4,500 μg kg⁻¹ for chicken muscle and 50, 3,000, 6,000, and 9,000 μg kg⁻¹ for chicken liver) performing six replicates at each level. Mean recoveries of 77.9–94.2% with CVs of 3.2–8.7% were obtained. The method demonstrated to be suitable for the simultaneous determination of zoalene and 3-ANOT in chicken tissues.

     

Solution of the Dirac equation in the tridiagonal representation with pseudospin symmetry for an anharmonic oscillator and electric dipole ring-shaped potential

An anharmonic oscillatory potential is proposed in which a noncentral electric dipole is included. The pseudospin symmetry for this potential is investigated by working in a complete square integrable basis that supports a tridiagonal matrix representation of the wave operator. The resulting three-term recursion relation for the expansion coefficients of the wavefunctions (both angular and radial) are presented. The angular/radial wavefunction is written in terms of Jacobi/Laguerre polynomials. The discrete spectrum of the bound states is obtained by the diagonalization of the radial recursion relation. The algebraic properties of the energy equation are also discussed, showing the exact pseudospin symmetry.