检索结果-南通市图书馆

Electromagnetic Coupling of Negative Parity Nucleon Resonances N(1535) Based on Nonrelativistic Constituent Quark Model

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2018年第1期69卷 43-49页

作者： Sara Parsaei ali akbar rajabi Faculty of Physics Shahrood University of Technology P.O. Box ***-316 Shahrood Iran Shams Institute of Higher Education Golestan Province Gonbad Iran

The electromagnetic transition between the nucleon and excited baryons has long been recognized as an important source of information for understanding strong interactions in the domain of quark confinement. We study the electromagnetic properties of the excitation of the negative parity the N~*(1535) resonances in the nonrelativistic constituent quark model at large momentum transfers and have performed a calculation the longitudinal and transverse helicity amplitudes. Since the helicity amplitudes depend strongly on the quark wave function in this paper, we consider the baryon as a simple, non-relativistically three-body quark model and also consider a hypercentral potential scheme for the internal baryon structure, which makes three-body forces among three quarks. Since the hyper central potential depends only on the hyper radius, therefore, the Cornell potential which is a combination of the Coulombic-like term plus a linear confining term is considered as the potential for interaction between quarks. In our work, in solving the Schrodinger equation with the Cornell potential, the Nikiforov–Uvarov method employed, and the analytic eigen-energies and eigen-functions obtained. By using the obtained eigen-functions, the transition amplitudes calculated. We show that our results in the range Q^2> 2GeV^2 lead to an overall better agreement with the experimental data in comparison with the other three non-relativistic quark models.

关键词： electroexcitation nonrelativistic constituent quark model the negative parity the N^* (1535) resonances

A new non-microscopic study of cluster structures in light alpha-conjugate nuclei

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2017年第1期41卷 110-114页

作者： Niloufar Zoghi-Foumani Mohammad Reza Shojaei ali akbar rajabi Department of Physics Shahrood University of Technology P. O. Box: ***-316 Shahrood Iran

In this paper, the alpha-cluster state in light alpha-conjugate nuclei is studied and a new suitable local potential model for the α-cluster phase of these nuclei is suggested. Using the generalized Nikiforov-Uvarov（NU）method, the clusterization energy for ^8Be,^12C,^16O and ^20Ne nuclei is calculated. Based on the obtained results, the clustering phenomenon is more probable at energies among excited levels and it happens neither at ground state nor at excited states of light alpha-conjugate nuclei. It is found that the presented formulation for clustering phenomenon reproduces the results of previous experimental and theoretical attempts for the mentioned nuclei. The consistency of the obtained results with the previous experimental and theoretical predictions indicates the reliability of this formulation for various types of alpha-conjugate nuclei.

关键词： light alpha-conjugate nuclei alpha-cluster state cluster-cluster interaction Nikiforov-Uvarov(NU) method

Calculating Binding Energy for Odd Isotopes of Beryllium （7 ≤ A ≤ 13）

在线全文

学校读者我要写书评

暂无评论

Journal of Physical Science and Application 2015年第1期5卷 66-70页

作者： Fahime Mohammadzade ali akbar rajabi Lale Nickhah Department of Physics University of Shahrood Shahrood *** lran

In this article, we present exact solution of the Schr6dinger equation （for an N-identical body-force） for odd-A isotopes of Beryllium in the presence of Yukawa potential by Nikiforov-Uvarov （NU） method. The NU method can be used to solve second order differential equation. By this method, we find the wave equation and binding energy. Numerical results of binding energy are presented and show that these results are in good agreement with experimental values.

关键词： SchrOdinger equation yukawa potential NU method odd isotopes of beryllium binding energy wave equation.

Energy Levels of Spin-1/2 Particles with Yukawa Interaction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Physics 2014年第9期5卷 773-780页

作者： Mohammad Reza Shojaei ali akbar rajabi Maryam Farrokh Niloufar Zoghi-Foumani Department of Physics Shahrood University of Technology Shahrood Iran

In this article, Yukawa interaction is used to study the relativistic spin-1/2 particles and obtain their energy levels. The role of Yukawa potential on the spin and pseudospin symmetry solution is investigated systematically by solving the Dirac equation with attractive scalar S(r) and repulsive vector V(r) potentials. Bound state spectrum and wave functions of Yukawa potential are obtained. It is found that the energy eigenvalues strongly depend on the potential parameters.

关键词： Yukawa Interaction Dirac Equation Spin and Pseudospin Symmetry Spin-1/2 Particles

Celiac disease in South-West of Iran

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2006年第27期12卷 4416-4419页

作者： Rahim Masjedizadeh Eskandar Hajiani Jalal Hashemi ali akbar Shayesteh Karim Moula Tahereh rajabi From the Division of Gastroenterology and Hepatology Department of Internal MedicineAhwaz Jundishapur University of Medical SciencesAhwazIran Department of pathology Ahwaz Jundishapur University of Medical SciencesAhwazIran

AIM： Celiac disease is characterized by life-long gluten intolerance. Clinical features of patients with celiac disease are variable. Studies about the prevalence of celiac disease in our country are scarce and there is no study on the prevalence of celiac disease in southern Iran. In the current study, clinical, laboratory and histological features of 52 patients with celiac disease were evaluated. METHODS： In a cross sectional study we retrospectively studied the characteristics of 52 celiac patients at Ahwaz JundiShapour University Hospitals （AJSUH） from November 1, 1999 to 1st Sep 2004. Intestinal biopsy and serum antigliadin and anti-endomysium antibodies were used for the diagnosis of patients. Mucosal lesions were classified according to the criteria of Marsh. Antigliadin antibodies were measured with a commercial enzyme-linked immunosorbent assay. Anti-endomysium antibodies were analyzed by indirect immunofluorescence with the use of a section of monkey esophagus. Routine hematological and biochemical analyses and measurement of immunoglobulin levels were undertaken.RESULTS： Male： female ratio was 1.08. The mean ＋ SD patient age was 21 ＋ 4.5 years （range 10-70 years） and the most common symptoms were diarrhea and weight loss （78.8%） followed by fatigue （73.1%）, pallor （65.4%）, anorexia （40.4%）, abdominal distention （32.7%）, and failure to thrive （23.1%）. Diarrhea and weight loss and fatigue were the most common findings. Iron deficiency anemia was found in 63.2% of patients and this became normal after adoption of a gluten-free diet in all patients. Immunoglobulin A, IgG antigliadin antibodies and IgA anti-endomysium antibodies were found in 33 and 48 cases, 78.8% and 85.4% of patients, respectively. Biopsy of the small intestine revealed that 90.4% of patients had typical lesions according to the Marsh classification. CONCLUSION： Although classical presentation was seen in most of the patients, atypical clinical manifestations of celiac disease should

关键词： Celiac disease IgG endomysial autoantibodies Southern Iran

Seroepidemiology of hepatitis C and its risk factors in Khuzestan Province, South-West of Iran:A case-control study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2006年第30期12卷 4884-4887页

作者： Eskandar Hajiani Jalal Hashemi Rahim Masjedizadeh ali akbar Shayesteh Esmail Idani Tahereh rajabi Division of Gastroenterology and Hepatology Department of Internal Medicine Ahwaz Jundishapur University of Medical Sciences Ahwaz Iran Department of Internal Medicine Ahwaz Jundishapur University of Medical Sciences Ahwaz Iran Department of Pathology Ahwaz Jundishapur University of Medical Sciences Ahwaz Iran

AIM：To evaluate possible risk factors for the spread of hepatitis C infection and to analyze the characteristics of the epidemiological and clinical patterns among the patients with hepatitis C infection. METHODS： During a five-year period a cross-sectional study was conducted among HCV positive individuals referred to the Ahwaz JundiShapour University Hospitals （AJSUH） and Hepatitis Clinic from 1 Sept 1999 to 1 Sept 2003. The control group consisted of first time blood donors referred to the Regional Blood Transfusion organization. Enzyme-linked immunosorbent assay and recombinant immunoblot assay anti-hepatitis C virus （HCV） tests were performed for two groups. Positive serum specimens were retested using polymerase chain reaction （PCR） for HCV RNA. Risk factors were evaluated using a questionnaire. Reported risk factors among infected subjects （＂HCV-positive＂） were compared to those of subjects never exposed （＂HCV-negative＂） to HCV. RESULTS： A total of 514 subjects were studied for HCV, of which 254 were HCV-positive and 260 HCV- negative donors comprised the control group. Mean age of the patients was 28.4 （Std 15.22） years. HCV-positive subjects were more likely to be of male gender （63% versus 37%）. Transfusion 132 （52%）, non-intravenous （n-iv） drug abuse and iv drug abuse 37 （14.5%）, haemodialysis 25 （10%）, receiving wounds at war and extramarital sexual activities （2.4%）, tattooing （3.6%） were found to be independent risk factors of being HCV-positive. No apparent risk factors could be demonstrated in 29 （11.2%） of the positive cases. CONCLUSION： Our data indicate that a history of transfusion and iv drug abuse and haemodialysis are important risk factors for HCV infection in our area and that more careful pretransfusion screening of blood for anti- HCV must be introduced in our blood banks. Improvements in certain lifestyle patterns, and customs in this area may be essential to prevent transmission of the infection.

关键词： Epidemiological patterns Hepatitis C virus Risk factors South-West of Iran

Using neural network modeling to improve the detection accuracy of land subsidence due to groundwater withdrawal

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第7期21卷 2320-2333页

作者： ali M.rajabi ali EDALAT Yasaman ABOLGHASEMI Mahdi KHODAPARAST Department of Engineering Geology University of TehranTehran ***Iran Department of Civil Engineering University of QomQom ***Iran

Despite the high efficiency of remote sensing methods for rapid and large-scale detection of subsidence phenomena,this technique has limitations such as atmospheric impact and temporal and spatial decorrelation that affect the accuracy of the *** paper proposes a method based on an artificial neural network to improve the results of monitoring land subsidence due to groundwater overexploitation by radar interferometry in the aliabad plain(Central Iran).In this regard,vertical ground deformations were monitored over 18 months using the Sentinel-1A SAR *** model the land subsidence by a multilayer perceptron(MLP)artificial neural network,four parameters,including groundwater level,alluvial thickness,elastic modulus,and transmissivity have been *** model's generalizability was assessed using data derived for 144 *** to the results,the neural network estimates the land subsidence at each ground point with an accuracy of 6.8 mm.A comparison between the predicted and actual values indicated a significant *** MLP model can be used to improve the results of subsidence detection in the study area or other areas with similar characteristics.

关键词： DInSAR Land subsidence Groundwater withdrawal aliabad plain Artificial neural network

Bound States for Hypercentral Singular and Exponential Potentials

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2006年第4期45卷 669-674页

作者： A.A. rajabi Physics Department Shahrood University of Technology P.O. Box ***-316 Shahrood iran

With a view to obtaining an exact closed form solution to the Schroedinger equation for a variety of hypercentral potentials, we investigate further application of an ansatz. This method is good enough for many kinds of potentials, but in this article it applies to a type of the hypercentral singular potentials V（x） = ax^2 ＋ bx^-4＋ cx^-6 and exponential hypercentral Morse potential U （x） = Uo （ e^-2ax - 2 e^-ax） for three interacting particles. The Morse potential is used for diatomic molecule while this method will be successfully used for many atomic molecules. The three-body potentials are more easily introduced and treated within the hyperspherical harmonic formalism. The internal particle motion is usually described by means of Jacobi relative coordinates p, A, and R, in terms of three particle positions r1, r2, and r3. We discuss some results obtained by using harmonic and anharmonic oscillators, however the hypercentral potential can be easily generalized in order to allow a systematic anaiysis, which admits an exact solution of the wave equation. This method is also applied to some other types of three-body, four-body, ..., interacting potentials.

关键词： hyperspherical harmonic anharmonic three-body Jacobian hypercentral hyperradial

Second-order modeling of non-premixed turbulent methane-air combustion

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2021年第11期28卷 3545-3555页

作者： ali ERSHADI Mehran rajabi ZARGARABADI Faculty of Mechanical Engineering Semnan UniversityP.O.B.35131-191SemnanIran Department of Mechanical Engineering Dezful BranchIslamic Azad UniversityDezfulIran

The main purpose of this research is the second-order modeling of flow and turbulent heat flux in nonpremixed methane-air combustion.A turbulent stream of non-premixed combustion in a stoichiometric condition,is numerically analyzed through the Reynolds averaged Navier-Stokes(RANS) *** modeling radiation and combustion,the discrete ordinates(DO) and eddy dissipation concept model have been *** Reynolds stress transport model(RSM) also was used for turbulence *** THF in the energy equation,the GGDH model and high order algebraic model of HOGGDH with simple eddy diffusivity model have been *** the numerical results of the SED model(with the turbulent Prandtl 0.85) and the second-order heat flux models with available experimental data follows that applying the second-order models significantly led to the modification of predicting temperature distribution and species mass fraction distribution in the combustion *** of turbulent Prandtl number in the combustion chamber shows that the assumption of Pr_(t) of 0.85 is far from reality and Pr_(t) in different areas varies from 0.4 to 1.2.

关键词： combustion modeling turbulent Prandtl number second-order models Reynolds stress transport model