检索结果-南通市图书馆

possible Origin of Magnetic Fields in Very Dense Stars

在线全文

学校读者我要写书评

暂无评论

Chinese physics Letters 2004年第11期21卷 2117-2119页

作者： A.pérezMartínez H.pérezRojas H.j.MosqueraCuesta GrupodeFisicaTeorica ICIMAFCalleENo.309VedadoLaHabanaCuba CentroBrasileirodepesquisasFísicas LaboratóriodeCosmologiaeFísicaExperimentaldeAltasEnergiasRuaDr.XavierSigaud150Cep22290-180.UrcaRiodeJaneiroRJBrazil

We discuss the bosonization of a relativistic very dense Fermi gas in a magnetic field and the consequent Bose-Einstein condensation of the resulting relativistic vector gas of charged particles. The model may be applied to paired spin-up electrons. We show that such systems may maintain self-consistently magnetic fields of order 10(10) - 10(13) G. That pairing could be the origin of large magnetic fields in some white dwarfs and neutron stars. For fields large enough (similar to10(13) for white dwarfs), the system becomes unstable and collapses.

关键词： Quantum gases liquids and solids Gravitation and cosmology Statistical physics and nonlinear systems Astrophysics and astroparticles

Report　on　Rare　Earth　Market　Evolution　and　Involvement　of　Rhone－poulenc　in　the　Market

维普期刊数据库评论

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 Rare Earths 1995年第2期13卷 128-132页

作者： Matthews j D Vanderstricht j p(Rhone-poulenc Rare Earths and Gallium) Rhone-poulenc Rare Earths and Gallium La Rochelle France

The first production of rare earths by the business now called Rhone poulenec Rare Earths and Gallium was at the tum of the ceritury in Normandy, northern France under the name Societedes Terres Rares. Manufacturing of rare earths started at La Rochelle on the west coast of France in 1946 and at Freeport in Texas in 1981 . Since 1988 we have maintained a production unit in japan also, originally in cooperation with Sumitomo Metal Mining and more recently with Santoku Metal Industries.

关键词： Rare earths Rare earth market Rhone-poulenc

肾上腺素对促肾上腺皮质激素分泌的影响及其作用机制的初步探讨

在线全文

学校读者我要写书评

暂无评论

中国医学科学院学报 1987年第3期9卷 193-197页

作者：许荣(火昆),Antunes-Rodrigues j,mccann SM 中国医学科学院基础医学研究所生理研究室巴西Sao paulo大学美国Texas大学卫生科学中心北京

对颈外静脉预先置入硅橡胶导管的大鼠注射肾上腺素,应用放射免疫测定法,直接测定血浆促肾上腺皮质激素(ACTH)浓度的改变,以了解肾上腺素影响肾上腺皮质活动的机理。实验在脑内正中隆起损伤和假损伤两组动物中进行,结果外周给肾上腺素兴... 详细信息

对颈外静脉预先置入硅橡胶导管的大鼠注射肾上腺素,应用放射免疫测定法,直接测定血浆促肾上腺皮质激素(ACTH)浓度的改变,以了解肾上腺素影响肾上腺皮质活动的机理。实验在脑内正中隆起损伤和假损伤两组动物中进行,结果外周给肾上腺素兴奋垂体前叶释放ACTH,从而兴奋肾上腺皮质的活动;作用点在下丘脑,兴奋促肾上腺皮质激素释放激素(CRF)的分泌,而非直接作用于腺垂体.

关键词：肾上腺素促肾上腺皮质激素促肾上腺皮质激素释放激素正中隆起

On the analytical solution of transient friction in channel flows

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1447-1466页

作者： F.j.GARCíA-GARCíA p.FARINAS-ALVARINO Department of Naval&Industrial Engineering Polytechnic School of EngineeringUniversity of A CorunaCampus Industrial de FerrolFerrol 15403A CorunaSpain Integraciones Técnicas de Seguridad S.A.Pol.Ind.Espiritu SantoC/Nobel15Cambre 15650A CorunaSpain

The transient friction in channel mean flows is the sum of two contributions,i.e.,the underlying laminar flow(ULF)and the purely turbulent component(pTC),and the contributions are analyzed separately by theoretical *** is found that,the transient friction may be higher or remarkably lower than that in equal-Reynolds number steady-state *** universal time constant for plane-parallel laminar flows is reported,and the role of the time constant in a turbulent mean flow is *** is shown that the time constant is related to the turbulence's frozen ***,a study of the logarithmic layer during the transient flow is accomplished,which shows that the logarithmic layer is destroyed.

关键词： transient friction transient flow unsteady channel flow

A statistical study of the interdependence of solar wind parameters

在线全文

学校读者我要写书评

暂无评论

Chinese journal of Astronomy and Astrophysics 2009年第4期9卷 485-493页

作者： Shollykutty john p. j. Kurian Department of physics St Joseph’s CollegeAlappuzha.Kerala-688012 India physics Research Centre St.Berchmans’ CollegeChanganacherry Kerala-686101 India

Correlation analysis of solar wind parameters, namely solar wind velocity, proton density, proton temperature and mean interplanetary magnetic field （IMF） from the ACE spacecraft data near Earth, was done. To our best knowledge, this study is a novel one since we consider here only the parameters inside the solar wind, including the mean IMF and, hence, the solar wind is a self consistent system. We have proposed a Multiple Linear Regression （MLR） model for the prediction of the response variable （solar wind velocity） using the parameters proton density, proton temperature and mean IMF measured as daily averages. About 60% of the observed value can be predicted using this model. It is shown that, in general, the correlation between solar wind parameters is significant. A deviation from the prediction at the solar maximum is interpreted. These results are verified by a graphical method.

关键词： solar wind-statistical model-correlation-solar wind parameters

A nucleon-pair and boson coexistent description of nuclei

在线全文

学校读者我要写书评

暂无评论

Chinese physics C 2017年第7期41卷 67-72页

作者：戴连荣潘峰 j.p.Draayer Department of physics Liaoning Normal University Dalian 116029 China Department of physics and Astronomy Louisiana State University Baton Rouge LA 70803-4001 USA

We study a mixture of s-bosons and like-nucleon pairs with the standard pairing interaction outside an inert core. Competition between the nucleon-pairs and s-bosons is investigated in this scenario. The robustness of the BCS-BEC coexistence and crossover phenomena are examined through an analysis of pf-shell nuclei with realistic single-particle energies, in which two configurations with pauli blocking of nucleon-pair orbits due to the formation of the s-bosons is taken into account. When the nucleon-pair orbits are considered to be independent of the s-bosons, the BCS-BEC crossover becomes smooth, with the number of the s-bosons noticeably more than that of the nucleon-pairs near the half-shell point, a feature that is demonstrated in the pf-shell for several values of the standard pairing interaction strength. As a further test of the robustness of the BCS-BEC coexistence and crossover phenomena in nuclei, results are given for B（E2; 01^＋→21^＋） values of even-even ^102-130 Sn with ^100Sn taken as a core and valence neutron pairs confined within the 1d（5/2）, 0g（7/2）, 1d（3/2）, 2s（1/2）, 1h（11/2）orbits in the nucleon-pair orbit and the s-boson independent approximation. The results indicate that the B（E2） values are reproduced well.

关键词： shell model interacting boson model the BCS-BEC coexistence

ON THE UNIQUENESS OF THE WEAK SOLUTIONS OF A QUASILINEAR HYpERBOLIC SYSTEM WITH A SINGULAR SOURCE TERM

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2002年第3期23卷 317-324页

作者： j.p.DIAS M.FIGUEIRA Dedicated to the memory of jacques-Louis Lions Dedicated to the memory of Jacques-Louis Lions

This paper is a continuation of the authors' previous paper [1]. In this paper the authors prove, assuming additional conditions on the initial data, some results about the existence and uniqueness of the entropy weak... 详细信息

关键词： Cauchy problem Weak solution Quasilinear hyperbolic system

Comparison of Different Formulations for the Numerical Calculation of Unsteady Incompressible Viscoelastic Fluid Flow

在线全文

学校读者我要写书评

暂无评论

Advances in Applied Mathematics and Mechanics 2010年第4期2卷 483-502页

作者： L.j.Amoreira p.j.Oliveira Departamento de Fisica Unidade de Detecccao RemotaUniversidade da Beira InteriorP6201-001 CovilhãPortugal Departamento de Engenharia Electromecânica Unidade de Materiais Têxteis e PapeleirosUniversidade da Beira InteriorP6201-001 CovilhãPortugal

In this paper we compare different methods currently used in the stabilization of numerical simulations of time-dependent viscoelastic fluid flows described with the Oldroyd-B and related *** methods under consideration,based on the separation of newtonian-like components from the stress tensor,are applied to a finite volume analysis of two simple benchmark problems(the plane poiseuille startup and pulsated flows),for which analytical solutions are *** relative performances of each method are evaluated regarding stability,accuracy and efficiency.

关键词： Time-dependent viscoelastic flows oscilating flow start-up flow computational rheology

Luminescent properties of dysprosium(III) ions in LaAlO_3 nanocrystallites

维普期刊数据库评论

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 Rare Earths 2011年第12期29卷 1195-1197页

作者： K.Lemański p.j.Dereń Institute of Low Temperature and Structure Research Polish Academy of Sciences

The absorption and emission spectra as well as decay time profile of Dy^3＋ ions in LaAlO3 nanocrystals were analyzed. The crystal structure of LaAlO3 was confirmed from XRD measurement. The emission peaks from blue to red came from main emitting level of dysprosium ^4F9/2 to the ground and other excited levels of Dy^3＋ ions. Cross relaxation process led to non-radiative quenching of luminescence, so that the lifetime of the ^4F9/2 energy level ions decreased with increasing amount of doped Dy^3＋ ions. The cross relaxation transfer rates were experimentally determined as a fimction of Dy^3＋ concentration.

关键词： LaAlO3 dysprosium luminescence nanocrystals cross relaxation rare earths