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Systematic distortion in cosmic microwave background maps

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Science china(physics,Mechanics & Astronomy) 2009年第5期52卷 804-808页

作者： LIU Hao 1,3.&LI TiPei 1,2.1Key Laboratory of Particle Astrophysics,{2. of high {3. physics,chinese Academy of sciences,Beijing 100049,china 2.enter for Astrophysics,Tsinghua University,Beijing 100084,china 3.Graduate University of chinese Academy of sciences,Beijing 100049,china Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China Graduate University of chinese Academy of sciences Beijing China Center for Astrophysics Tsinghua University Beijing China

To minimize instrumentally the induced systematic errors,cosmic microwave background(CMB)anisotropy experiments measure temperature differences across the sky using pairs of horn antennas, temperature map is recovered from temperature difference obtained in sky survey through a map-making *** inspect and calibrate residual systematic errors in the recovered temperature maps is important as most previous studies of cosmology are based on these *** analyzing pixel-ring coupling and latitude dependence of CMB temperatures,we find notable systematic devia- tion from CMB Gaussianity in released Wilkinson Microwave Anisotropy Probe(WMAP)*** detected deviation cannot be explained by the best-fit LCDM cosmological model at a confidence level above 99%and cannot be ignored for a precision cosmology study.

关键词： cosmology cosmic microwave background methods data analysis

Optimal reactions for the synthesis of superheavy nucleus ^(2.0)Hs

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Science china(physics,Mechanics & Astronomy) 2006年第6期49卷 641-648页

作者： LIU Zuhua1,3.& BAO Jingdong1,2.1. Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University, Beijing 100875, china 2. {2. Department, Beijing Normal University, Beijing 100875, china 3. china institute of Atomic energy, Beijing 102.13. china Key Laboratory of Beam Technology and Material Modification of Ministry of Education Beijing Normal University Beijing China china institute of Atomic {2. Beijing China physics Department Beijing Normal University Beijing China

The superheavy nucleus 2.0Hs is expected to be a “double-magic” deformed nucleus. We have calculated its cross sections of evaporation residue for the reactions 2.8Cm(2.Mg,4n)2.0Hs, 2.4Pu(3.Si,4n)2.0Hs, 2.0}U(3.S,4n)2.0Hs and 2.6Ra(48Ca,4n)2.0Hs using a two-parameter Smoluchowski equation. It is found from our results that 2.6Ra(48Ca,4n)2.0Hs and 2.0}U(3.S,4n)2.0Hs are two optimal reactions for the synthesis of the superheavy nucleus 2.0Hs due to their large negative Q-values.

关键词： diffused fusion barrier,Smoluchowski equation,superheavy nuclei.

Isospin-dependent relativistic microscopic optical potential in the Dirac Brueckner-Hartree-Fock method

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Science china(physics,Mechanics & Astronomy) 2004年第2期47卷 189-198页

作者： RONG Jian1 & MA Zhongyu1,2.3.1. china {2. of Atomic energy, Beijing 102.13. china 2. Center of Nuclear Theoretical physics, National Laboratory of Heavy Ion Accelerator of Lanzhou, Lan-zhou 73.000, china 3. {2. of Theoretical physics, {12. Academy of sciences, Beijing 100080, china Correspondence should be addressed to Rong Jian (email: jrong@***) china institute of Atomic {2. Beijing China Center of Nuclear Theoretical physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou China institute of Theoretical physics Chinese Academy of Sciences Beijing China

The relativistic microscopic optical potential in the asymmetric nuclear matter is studied in the framework of the Dirac Brueckner-Hartree-Fock method. A new decomposition of the Dirac structure of the nuclear self-energy in nuclear matter is adopted. The self-energy of a nucleon with E > 0 in nuclear matter is calculated with the G matrix in the Hartree-Fock approach. The optical potential of a nucleon in the nuclear medium is identified with the nucleon self-energy. The energy and asymmetric parameter dependence of the relativistic optical potentials for proton and neutron are discussed. The resulting Schroedinger equivalent potentials have reasonable behaviors of the energy dependence. The asymmetric parameter dependence of relativistic optical potentials and Schroedinger potentials are emphasized.

关键词： Dirac Brueckner Hartree-Fock, relativistic microscopic optical potential, asymmetric nuclear matter, isospin-dependence.

A new principle of synthetic cascade utilization of chemical energy and physical energy

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Science china(Technological sciences) 2005年第2期48卷 163-179页

作者： JIN Hongguang1, HONG Hui1,2. WANG Baoqun1,2. HAN Wei1,2.& LIN Rumou1,2.1. institute of Engineering Thermophysics, {2. Academy of {3., Beijing 100080, china 2. Graduate School of the {2. Academy of {3., Beijing 10003., china institute of Engineering Thermophysics Chinese Academy of Sciences Beijing China Graduate School of the chinese Academy of sciences Beijing China

We propose a new principle of the cascade utilization of both chemical energy and physical energy in energy systems with the integration of chemical processes and thermal cycles. Particularly, a general equation of energy levels of substance, Gibbs free energy of chemical reaction and physical energy is explicitly founded. On the basis of this equation, a chemical-looping combustion and an indirect combustion are investigated. Furthermore, a mechanism of energy release, with the combination of decreasing the energy level of Gibbs free energy and upgrading the energy level of low or middle- temperature thermal energy, is clarified. The promising results obtained here establish a theoretical basis for the further investigation of multi-function systems in which energy and the environment are compatible, and create a new approach to improve the performance of traditional thermal cycles.

关键词： chemical energy, cascade utilization, exergy, energy conversion.

IMAGING IN high energy ASTRONOMY

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空间科学学报 1998年第S1期18卷 12-20页

作者： LI Ti-pei (institute of high Enerpy {2., The {3. Academy of sciences, Beijing 10003.)

Space research is usually costly, and this restricts participation of developing countries. With traditional techniques one must construct high resolution instrument,more and more complicated and expensive, to obtain high resolution results from space observations. It is a difficult task to make observations with both high sensitivity and high resolution. Applying advanced inversion technique, one can subtract more information from old data in public domain,and, furthermore, conduct high sensitive and high-resolution experiments with low-cost low-resolution instruments. So developing and applying data analysis technique is of great importance for developing countries to do basic space *** this paper we summarize efforts of chinese scientists in recent years along this direction on imaging in space high energy astronomy.

关键词： Space astronomy Astronomical satellite Imaging

Statistical theory for hydrogen bonding fluid system of A_aD_d type (I): The geometrical phase transition

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Science china Chemistry 2006年第6期49卷 499-506页

作者： WANG Haijun1,2. HONG Xiaozhong3. GU Fang1 & BA Xinwu1 1. College of Chemistry and Environment Science, Hebei University, Baoding 071002. china 2. International Center for Materials {2., chinese Academy of {3., Shenyang 110016, china 3. College of {2. Science and Technology, Hebei University, Baoding 071002. china College of Chemistry and Environment Science Hebei University Baoding China International Center for Materials physics Chinese Academy of Sciences Shenyang China College of physics Science and Technology Hebei University Baoding China

The influence of hydrogen bonds on the physical and chemical properties of hydrogen bonding fluid system of AaDd type is investigated from two viewpoints by the principle of statistical mechanics. In detail, we proposed two new ways that can be used to obtain the equilibrium size distribution of the hydrogen bonding clusters, and derived the analytical expression of a relationship between the hydrogen bonding free energy and hydrogen bonding degree. For the nonlinear hydrogen bonding systems, it is shown that the sol-gel phase transition can take place under proper conditions, which is further proven to be a kind of geometrical phase transition rather than a thermodynamic one. Moreover, several problems associated with the geometrical phase transition and liquid-solid phase transition in nonlinear hydrogen bonding systems are discussed.

关键词： hydrogen bonding fluid, equilibrium free energy, geometrical phase transition.

Surface Nanocrystallization of Magnesium Alloy AZ91D by high-energy Shot Peening

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Journal of Wuhan University of Technology(Materials Science) 2009年第4期24卷 515-519页

作者：张津 School of Materials Science & Engineering University of Science and Technology Beijing College of Materials Science & Engineering Chongqing University of Technology

high-energy shot peening （HESP）, a method to produce severe plastic deformation by high velocity flying balls, was applied on die cast magnesium alloy AZ91D. Effects of surface nanocrystallization by HESP and heat treatment at different temperatures were investigated. The mi- crostructure evolution was conducted using X-ray diffraction （XRD） and field emission scanning electronic microscopy （FESEM）. The hardness was measured by microhardness tester. The experimental results show that surface nanocrystrallization of AZ91D obtained by HESP would lead to the increase of microhardness. Low temperature heated at 100℃ for 1 h do not change the property obviously. However, both the microstructure and microhardness vary greatly after heat treatment at 400℃ for 1 h.

关键词： AZ91 D surface nanocrystallization HESP microhardnss corrosion resistance

The study of energy bands in nucleus ^(102.Zr

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Science china(physics,Mechanics & Astronomy) 2010年第1期53卷 106-110页

作者： DONG GuoXiang 1,2., YU ShaoYing 1,2.3., LIU YanXin 1 , SHEN CaiWan 1,2.4 & DONG YongSheng 1,2.5I School of Science, Huzhou Teachers College, Huzhou 3.3.00, china 2.School of Science and Information Engineering, Zhejiang Normal University, Jinhua 3.1000, china 3.institute of Theoretical {3., chinese Academy of sciences, Beijing 100080, china 4 Center of Theoretical Nuclear {3., National Laboratory of Heavy Ion Accelerator of Lanzhou, Lanzhou 73.000, china 5 Department of {3., Jining Teachers College, Jining 012.00, china School of Science Huzhou Teachers College Huzhou China School of Science and Information Engineering Zhejiang Normal University Jinhua China institute of Theoretical physics Chinese Academy of Sciences Beijing China Center of Theoretical Nuclear physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou China Department of physics Jining Teachers College Jining China

Theoretical calculations of the energy bands in nucleus 102.Zr are carried out by taking the projected shell model approach, which has reproduced the experimental data. In addition, by analyzing band-head energies, corresponding configurations of yrast band, quasi-particle rotational bands and side bands, we have worked out the microscopic formation mechanism of axially symmetric deformation bands: The low-excitation deformation bands are attributed to the high-j intruder states 1g 7/2.and 1h 11/2.in the N=4, 5 shells; the quasi-particles in the orbit v5/2.[5{2.], v{2.2.[411] and v{2.2.[41{2. in particular play an important role in the deformation of 102.Zr.

关键词： projected shell model yrast band quasi-particle rotational band side band

Constraints on smoothness parameter and dark energy using observational H(z) data

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Research in Astronomy and Astrophysics 2011年第2期11卷 125-136页

作者： Hao-Ran Yu1,Tian Lan1,Hao-Yi Wan2.Tong-Jie Zhang1,3.and Bao-Quan Wang4 1 Department of Astronomy,Beijing Normal University,Beijing 100875,china 2.Business Office,Beijing Planetarium,Beijing 100044,china 3.Center for high {3. physics,Peking University,Beijing 100871,china 4 Department of physics,Dezhou University,Dezhou 2.3.2.0}china Department of Astronomy Beijing Normal University Beijing 100875 China Business Office Beijing Planetarium Beijing 100044 China Center for high energy {2. Peking University Beijing 100871 China Department of physics Dezhou University Dezhou 253023 China

With large-scale homogeneity,the universe is locally inhomogeneous,clustering into stars,galaxies and larger *** property is described by the smoothness parameter α which is defined as the proportion of matter in the form of intergalactic *** we consider the inhomogeneities over a small scale,there should be modifications of the cosmological distances compared to a homogenous *** and Roeder developed a second-order ordinary differential equation（D-R equation） that describes the angular diameter distance-redshift relation for inhomogeneous cosmological ***,we may obtain the D-R equation for observational H（z） data（OHD）.The density-parameter ΩM,the state of dark energy ω,and the smoothness-parameter α are constrained by a set of OHD in a spatially flat XCDM universe as well as a spatially flat XCDM *** using a χ2.minimization method,we get α = 0.81＋0.19-0.2. and ΩM = 0.3.＋0.12.0.06 at the 1σ confidence *** we assume a Gaussian prior of ΩM = 0.2. ± 0.1,we get α = 0.93.0.07-0.19 and ΩM = 0.3.＋*** the XCDM model,α is constrained to α≥ 0.80 but ω is weakly constrained around-1,where ω describes the equation of state of the dark energy（pX = ωρX）.We conclude that OHD constrains the smoothness parameter more effectively than the data of SNe Ia and compact radio sources.

关键词： cosmology -- dark energy -- cosmological parameters