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Spontaneous chiral-symmetry breaking of lattice QCD with massless dynamical quarks

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Science china(physics,Mechanics & Astronomy) 2007年第1期50卷 6-14页

作者： LUO XiangQian department of physics,School of physics and engineering,Sun Yat-Sen university,Guangzhou 510275,china 1. department of physics School of Physics and Engineering Sun Yat-Sen University Guangzhou 510275 China

One of the most challenging issues in QCD is the investigation of spontaneous chiral-symmetry breaking, which is characterized by the non-vanishing chiral condensate when the bare fermion mass is zero. In standard methods of the lattice gauge theory, one has to perform expensive simulations at multiple bare quark masses, and employ some modeled functions to extrapolate the data to the chiral limit. This paper applies the probability distribution function method to computing the chiral condensate in lattice QCD with massless dynamical quarks, without any ambiguous mass extrapolation. The results for staggered quarks indicate that this might be a promising and efficient method for investigating the spontaneous chiral-symmetry breaking in lattice QCD, which deserves further investigation.

关键词： lattice QCD spontaneous chiral-symmetry breaking dynamical quarks

Current distribution and stability of LTS/HTS hybrid superconducting conductors

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Science china(Technological Sciences) 2010年第7期53卷 2000-2007页

作者： GUAN XiaoJin1,2, WANG YinShun1 & ZHOU WeiWei3 1 Key Laboratory of HV and EMC beijing, North china Electric Power university, beijing 102206, china 2 department of physics, Baoding university, Baoding 071000, china 3 Institute of Electrical engineering, Chinese Academy of Sciences, beijing 100190, china 1. Key Laboratory of HV and EMC beijing North China Electric Power University Beijing 102206 China2. Department of Physics Baoding University Baoding 071000 China3. Institute of Electrical Engineering Chinese Academy of Sciences Beijing 100190 China

Current distribution and stability of a hybrid LTS/HTS superconductor, consisting of multifilamentary NbTi/Cu and Bi2223/Ag tapes, were numerically analyzed according to power-law models. The results showed that most of current passed through the LTS and the current increased in the HTS with temperature rise when the transport current was below the critical current of the hybrid conductor. The quench propagation velocity of the hybrid conductor was smaller but its minimum quench energy was larger than those of LTS conductors, indicating that the stability of the hybrid superconducting conductor was effectively improved and a high engineering current density was simultaneously achieved. Finally, a hybrid sample, made by soldering Bi2223/Ag tape onto NbTi/Cu conductor, was prepared and tested successfully at helium temperature. The experimental results qualitatively agreed with the simulated ones.

关键词： distribution hybrid conductor minimum quench energy quench propagation velocity n value stability

Electronic structure and magnetism of R(Fe,Si)_(12) (R=Y,Nd)

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Science china(physics,Mechanics & Astronomy) 2006年第2期49卷 195-202页

作者： SUN Guang’ai1, CHEN Bo1, DU Honglin2, FAN Zhijian1, GAO Tao3 & QI Xinhua31. Institute of Nuclear physics and Chemistry, china Academy of engineering physics, Mianyang 621900, china 2. department of physics, Peking university, beijing 100871, china 3. Institute of Atomic and Molecular physics, Sichuan university, Chengdu 610065, china 1. Institute of Nuclear physics and Chemistry China Academy of Engineering Physics Mianyang 621900 China 2. department of physics Peking university Beijing 100871 China 3. Institute of Atomic and Molecular physics Sichuan University Chengdu 610065 China

The newly developed full-potential linearized augmented plane wave (LAPW) and local orbitals (lo) based on standard APW methods are briefly introduced, and the structure and magnetic properties of R(Fe, Si)12 compounds (R = Y, Nd) are calculated using the method. The distribution of Si at different sites is analyzed based on total energy of one crystal unit with structure having been optimized. The characters of magnetic mo-ments, total density of states (TDOS) and partial density of states (PDOS) for different crystal sites Si occupies are obtained and analyzed. The results show that the total mag-netic moments of RFe10Si2 (R = Y, Nd) are larger than those of RFe10M2 (M = Ti, V, Cr, Mn, Mo and W) and the hybridization mechanism is seen as follows. Si(8j) reduce the mag-netic moments of Fe at three sites, however, Si(8f) mainly reduce the magnetic moments of Fe(8i) and Fe(8j) atoms. The Curie temperature is markedly enhanced by the introduc-tion of Si atoms according to spin fluctuation of DOS at Fermi level.

关键词： (L)APW+lo method R(Fe Si)12(R = Y Nd) magnetic moment Density of state.

Detect early stage lung cancer by a LAMP microfluidic chip system with a real-time fluorescent filter processor

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Science china Chemistry 2012年第4期55卷 508-514页

作者： WANG TongZhou1, ZHANG Ye1, HUANG GuoLiang1,2,3, WANG Can2, XIE Lan1, MA Li2, LI ZhiYong2, LUO XianBo2, TIAN Hao2, LI Qiang1, LI Xin1, LV ZhouYan1 & BAO XiaoFan11department of Biomedical engineering, School of Medicine, tsinghua university, beijing 100084, china 2National engineering Research center for beijing Biochip Technology, beijing 102206, china 3Yangtze Delta Region Institute of tsinghua university, Hangzhou 330401, china 1. department of Biomedical engineering School of Medicine Tsinghua University Beijing 100084 China2. National Engineering Research Center for Beijing Biochip Technology Beijing 102206 China3. Yangtze Delta Region Institute of Tsinghua University Hangzhou 330401 China

This work presents a promising clinical molecular diagnostics for early stage lung cancer. This novel diagnostic method utilized the loopmediated isothermal amplification （LAMP）, micro fluidic chips and a confocal optical detector with a nonlinear fluorescent filter processor. An isothermal amplification based microfluidic chip for the early diagnostics of lung cancer was developed and a confocal optical detector was improved by a novel real-time fluorescent filter to sensitively monitor the DNA amplification procedure with high signal to noise ratio and fluorescence collecting ability. Experiment showed that a rapid diagnostic of lung cancer by detecting the existence of the CEA mRNA could be performed in only 5 laL of reaction assay in less than 45 min. While the traditional intube RTPCR set consumed more than 25 -μL of the assay and took more than 90 rain.

关键词： microfluidic chip – isothermal amplification – lung cancer – confocal detection – non linear filter

The numerical method for three-dimensional impact with friction of multi-rigid-body system

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Science china(physics,Mechanics & Astronomy) 2006年第1期49卷 102-118页

作者： ZHAO Zhen1,2, LIU Caishan2 & CHEN Bin2 1. beijing Institute of Graphic Communication, beijing 102600, china 2. department of Mechanics & engineering Science, Peking university, beijing 100871, china beijing Institute of Graphic Communication Beijing 102600 China department of Mechanics & engineering Science Peking University Beijing 100871 China

The differential equations for planar impacts reduce to an algebraic form, and can be easily solved. For three dimensional impacts with friction, there is no closed-form solution, and numerical integration is required due to the swerve behavior of tangential impulse during collisions. The dynamic governing equations in the impact process are built up in impulse space based on the Lagrangian equation in this paper. The coefficient of restitution defined by Poisson is used as the condition of impact termination. A valid nu- merical method for solving three-dimensional frictional impact of multi-rigid body system is established. The singular cases of tangential movement in sticking point are especially noticed and analyzed. Several examples are present to reveal the different kinds of tan- gential movement modes varied with the normal impulse during collision.

关键词： multi-rigid body, impact, friction.

The principle of relativity, kinematics and algebraic relations

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Science china(physics,Mechanics & Astronomy) 2010年第4期53卷 591-597页

作者： GUO HanYing1, HUANG ChaoGuang2,3, WU HongTu4 & ZHOU Bin5 1Institute of Theoretical physics, Chinese Academy of Sciences, beijing 100190, china 2Institute of High Energy physics, Chinese Academy of Sciences, beijing 100049, china 3Theoretical physics center for Science Facilities, Chinese Academy of Sciences, beijing 100049, china 4department of Mathematics, Capital Normal university, beijing 100048, china 5department of physics, beijing Normal university, beijing 100875, china 1. Institute of Theoretical physics Chinese Academy of Sciences Beijing 100190 China2. Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China3. Theoretical Physics Center for Science Facilities Chinese Academy of Sciences Beijing 100049 China4. Department of Mathematics Capital Normal University Beijing 100048 China5. Department of Physics Beijing Normal University Beijing 100875 China

Based on the relativistic principle and the postulate of universal invariant constants (c, l), all kinematic symmetries can be set up as the subsets of the Umov-Weyl-Fock-Hua transformations for the inertial motions. ... 详细信息

关键词： principle of relativity with (c l) Umov-Weyl-Fock-Hua transformations kinematics special relativity triple

Micro-plate magnetic chemiluminescence immunoassay and its applications in carcinoembryonic antigen analysis

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Science china Chemistry 2010年第4期53卷 812-819页

作者： LI ZhiYong1, ZHANG QianYun2, ZHAO LiXia1, LI ZhenJia3, HU GuoMao3, LIN Jin-Ming2 & WANG Shan4 1State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research center for Eco-Environmental Sciences, Chinese Academy of Sciences, beijing 100085, china 2department of Chemistry, tsinghua university, beijing 100084, china 3beijing Chemclin Biotech Co., Ltd., beijing Academy of Science and Technology, beijing 100094, china 4School of Chemistry and Chemical engineering, Xianyang Normal College, Xianyang 712000, china 1. State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China2. Department of Chemistry Tsinghua University Beijing 100084 China3. Beijing Chemclin Biotech Co. Ltd. Beijing Academy of Science and Technology Beijing 100094 China4. School of Chemistry and Chemical Engineering of Xianyang Normal College Xianyang 712000 China

A micro-plate magnetic chemiluminescence immunoassay was developed for rapid and high throughput detection of carcinoembryonic antigens (CEA) in human sera. This method was based on a sandwich immunoreaction of fluorescein isothiocyanate (FITC)-labeled anti-CEA antibodies, CEA antigens, and horseradish peroxidase (HRP)-conjugated anti-CEA antibodies in mi- cro-plate. The immunomagnetic particles coated with anti-FITC antibodies were used as the solid phase for the immunoassay. The separation procedure was carried out by a magnetic plate adaptor and the luminol-hydrogen peroxide (H2O2)-HRP system was employed for the chemiluminescence detection. The proposed method combined the advantages of the micro-plate reactor and magnetic particle separation technology with the linear range of 5-250 ng mL·1. The detection limit of CEA was 0.61 ng mL·1. The coefficient of the variation was less than 7% and 13% for intra-assay and inter-assay precision, respectively. Compared with the commercial micro-plate chemiluminescent kit, the proposed method showed a good correlation.

关键词： micro-plate magnetic chemiluminescence immunoassay carcinoembryonic antigen tumor marker

Synthesis of superheavy nuclei with ^(238)U target

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Science china(physics,Mechanics & Astronomy) 2009年第10期52卷 1482-1488页

作者： LIU ZuHua1,3 & BAO JingDong2,4 1 Key Laboratory of Beam Technology and Material Modification of Ministry of Education,beijing Normal university,beijing 100875,china 2 department of physics,beijing Normal university,beijing 100875,china 3 china Institute of Atomic Energy,beijing 102413,china 4 center of Theoretical Nuclear physics,National Laboratory of Heavy Ion Accelerator of Lanzhou,Lanzhou 730000,china Key Laboratory of Beam Technology and Material Modification of Ministry of Education Beijing Normal University Beijing 100875 China department of physics Beijing Normal University Beijing 100875 China china Institute of Atomic Energy Beijing 102413 China center of Theoretical Nuclear physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou 730000 China

The production of superheavy nuclei with Z=108-116 via hot fusion reactions of the neutron-rich projectiles with 238U target is systematically *** results show that the production cross sections of superheavy nuclei do not decrease monotonously as the atomic number Z *** cross sections of the superheavy nuclei at Z = 112 and 115 are enhanced as compared with the whole Z-trend in synthesis of the superheavy nuclei,which clearly illustrates that the reactions with large negative Q-value and shell correction are more favorable to synthesize superheavy nuclei.

关键词： superheavy nuclei fusion reaction cross section 238U target

Heating effect and biocompatibility of bacterial magnetosomes as potential materials used in magnetic fluid hyperthermia

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Progress in Natural Science:Materials International 2012年第1期22卷 31-39页

作者： Rui-ting Liu a,Jie Liu a,c,Jie-qiong Tong a,c,Tao Tang a,b,Wei-Chao Kong a,c,Xiao-wen Wang a,Ying Li b,Jin-tian Tang a a Key Laboratory of Particle & Radiation Imaging(tsinghua university),Ministry of Education,department of engineering physics,tsinghua university,beijing 100084,china b State Key Laboratories for Agrobiotechnology and College of Biological Sciences,china Agricultural university,beijing 100083,china c department of Pharmaceutics,beijing university of Chinese Medicine,beijing 100102,china [a] Key Laboratory of Particle & Radiation Imaging (tsinghua university) Ministry of Education Department of Engineering Physics Tsinghua University Beijing 100084 China [b] State Key Laboratories for Agrobiotechnology and College of Biological Sciences China Agricultural University Beijing 100083 China [c] department of Pharmaceutics Beijing University of Chinese Medicine Beijing 100102 China

Magnetic fluid hyperthermia(MFH) promises to be a viable alternative in the treatment of localized cancerous *** treatment consists of introducing nanoparticles as energy absorbent agents in tumor tissue under an oscillating magnetic field,where nanoparticles dissipate energy in the form of heat,causing a localized rise in the temperature and tumor cell *** magnetic fluid under study is artificial magnetic *** work seeks to introduce the new natural biologic magnetic material bacterial magnetosomes(BMs) to be used in *** of magnetosomes and chemically synthesized magnetic nanoparticles(MNPs),such as morphology,magnetic properties and their heating effects under magnetic field were *** studies using human breast cancer cells MCF-7 indicated that cell viability could be significantly decreased by the heat derived from BMs and MNPs under alternative magnetic *** of BMs and MNPs was compared in terms of evaluating their acute toxicity in mice and their decomposition abilities in vitro,and it showed that magnetosomes exhibit a lower *** findings provide evidence for beneficial activities of magnetosomes in MFH and support the continued investigation of it to be applied in biomedicine.

关键词： Magnetosome Synthesized magnetic nanoparticles Magnetic fluid hyperthermia Properties Biocompatibility