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BRST quantization and canonical Ward identity of the supersymmetric electromagnetic interaction system

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science china(Physics,Mechanics & Astronomy) 2007年第3期50卷 339-347页

作者： HUANG YongChang1,3.4, JIANG YunGuo1 & LI XinGuo2.3.1 Institute of Theoretical Physics, College of Applied {2.s, Beijing University of Technology, Beijing 10002., china 2.Institute of Modern Physics, chinese {3. of {2.s, Lanzhou 73.000, china 3.Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Collisions, chinese {3. of {2.s, Lanzhou 73.000, china 4 china Center of Advanced {2. and Technology (World Laboratory), Beijing 100080, china Institute of Theoretical Physics College of Applied Sciences Beijing University of Technology Beijing China Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Collisions Chinese Academy of Sciences Lanzhou China china Center of Advanced science and Technology (World Laboratory) Beijing China Institute of Modern Physics Chinese Academy of Sciences Lanzhou China

According to the method of path integral quantization for the canonical constrained system in Becchi-Rouet-Stora-Tyutin scheme, the supersymmetric electromagnetic interaction system was quantized. Both the Hamiltonian of the supersymmetric electromagnetic interaction system in phase space and the quantization procedure were simplified. The BRST generator was constructed, and the BRST transforma- tions of supersymmetric fields were gotten; the effective action was calculated, and the generating functional for the Green function was achieved; also, the gauge generator was constructed, and the gauge transformation of the system was ob- tained. Finally, the Ward-Takahashi identities based on the canonical Noether theorem were calculated, and two relations between proper vertices and propaga- tors were obtained.

关键词： supersymmetric electromagnetic interaction BRST quantization Ward identity

Electron dynamics in collisionless magnetic reconnection with a PIC simulation

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chinese science Bulletin 2009年第3期54卷 456-460页

作者： GUO Jun1,2.1 School of Mathematics and Physics, Qingdao University of science and Technology, Qingdao 2.6042. china 2.State Key Laboratory of {2. Weather, {3. academy of sciences, Beijing 100080, china School of Mathematics and Physics Qingdao University of Science and Technology Qingdao China State Key Laboratory of space Weather Chinese Academy of Sciences Beijing China

Two-dimensional particle-in-cell (PIC) simulation is used to investigate electron dynamics in colli- sionless magnetic reconnection, and the proton/electron mass ratio is taken to be mi /me = 2.6. The results show that the presence of a strong initial guide field will change the direction of the electron flow. The electron density cavities and the parallel electric field can be found in the electron inflow re- gion along the separatrix, and the electron inflow and density cavities only appear in the second and fourth quadrants. What is different from the results with a smaller mass ratio is that new structures appear in the diffusion region near the X line: (1) Narrow regions of density enhancement and density cavities can be found synchronously in this region; and (2. corresponding to the electron density changes near the X line, the strong parallel electric fields are found to occur in the first and third quadrants. These electric fields perhaps play a more important role in acceleration and heating electrons than those fields located in the density cavities.

关键词： PIC模仿磁链接导向场电子动力学

Bifurcation stabilization of nonlinear systems by dynamic output feedback with application to rotating stall control

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science china(Information sciences) 2012年第1期55卷 200-213页

作者： CHEN PengNian1,QIN HuaShu2.WANG Yong3.HONG YiGuang2.1Department of Mathematics,china Jiliang University,Hangzhou 3.0018,china 2.nstitute of Systems science,The {3. academy of sciences,Beijing 100080,china 3.epartment of Mechanics,Peking University,Beijing 100871,china Department of Mathematics China Jiliang University Institute of Systems science The Chinese Academy of Sciences Department of Mechanics Peking University

The paper deals with the problem of stabilization of stationary bifurcation solutions of nonlinear systems via dynamic output *** is emphasized that the parameter of the system is not directly *** introduce the concepts of uniform observability of the inverse of a function of state and input and N-order-input-to-state bifurcation *** on the concepts,we propose a new method for designing dynamic compensators that guarantee bifurcation stability for the closed-loop *** an example,we apply the general theory to active control of rotating stall in axial flow compressors by designing a stabilizing dynamic compensator for the three-state Moore-Greitzer model with a class of cubic compressor characteristics.

关键词： bifurcation control uniform observability dynamic output feedback rotating stall

The gravitational gradient tensor’s invariants and the related boundary conditions

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science china Earth sciences 2010年第5期53卷 781-790页

作者： YU JinHai1,2.3.& ZHAO DongMing4 1 College of Earth science, Graduate University of {2. academy of sciences, Beijing 100049, china 2.Institute of Geodesy and Geophysics, {2. academy of sciences, Wuhan 43.077, china 3.State Key Laboratory of Astronautic Dynamics, Xi’an 710043. china 4 Zhengzhou Institute of Surveying and Mapping, Zhengzhou 450052. china College of Earth science Graduate University of Chinese Academy of Sciences Beijing China Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan China State Key Laboratory of Astronautic Dynamics Xi’an China Zhengzhou Institute of Surveying and Mapping Zhengzhou China

Here we report new approaches of recovering the Earth gravitational field from GOCE (Gravity field and steady-state Ocean Circulation Explorer) gradiometric data with the help of the gradient tensor’s invariants. Our results only depend on GOCE satellite’s position and gradiometry, in other words, they are completely independent of the satellite attitude. First, starting from the invariants, linearization models are established, which can be referred as the general boundary conditions on the satellite’s orbit. Then, the spherical approximation expressions for the models are derived, and the corresponding solving methods for them are discussed. Furthermore, considering effects of J2.term, the spherical approximation models are improved so that the accuracies of the boundary conditions can be theoretically raised to O ( J 2.2.T), which is approximately equivalent to O(T2.. Finally, some arithmetic examples are constructed from EGM96 model based on the derived theories, and the computational results illustrate that the spherical models have accuracies of 10-7 and the order recovering the gravitational field can reach up to 2.0, and the models with regard to effect of J2.term have accuracies of 10-8 and the order can reach up to 2.0.

关键词： the Earth’s gravitational field gravitational gravidiometry tensor’s invariant

Fiducial inference in the pivotal family of distributions

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science china Mathematics 2006年第3期49卷 410-432页

作者： XU Xingzhong & LI Guoying Department of Mathematics, Beijing Institute of Technology, Beijing 100081, china academy of Mathematics and Systems {2., {3. academy of {2.s, Beijing 100080, china Department of Mathematics Beijing Institute of Technology Beijing China academy of Mathematics and Systems science Chinese Academy of Sciences Beijing China

In this paper a family, called the pivotal family, of distributions is considered.A pivotal family is determined by a generalized pivotal model. Analytical results show that a great many parametric families of distributions are pivotal. In a pivotal family of distributions a general method of deriving fiducial distributions of parameters is proposed. In the method a fiducial model plays an important role. A fiducial model is a function of a random variable with a known distribution, called the pivotal random element, when the observation of a statistic is *** method of this paper includes some other methods of deriving fiducial distributions. Specially the first fiducial distribution given by Fisher can be derived by the method. For the monotone likelihood ratio family of distributions, which is a pivotal family, the fiducial distributions have a frequentist property in the Neyman-Pearson view. Fiducial distributions of regular parametric functions also have the above frequentist property. Some advantages of the fiducial inference are exhibited in four {2.s of the fiducial distribution. Many examples are given, in which the fiducial distributions cannot be derived by the existing methods.

关键词： confidence bounds, fiducial distributions, fiducial model, frequentist prop-erty, generalized pivotal model, pivotal family of distributions, testing hypotheses.

Validating global hydrological models by ground and space gravimetry

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chinese science Bulletin 2009年第9期54卷 1534-1542页

作者： ZHOU JiangCun1,2.3. SUN HePing1,2.& XU JianQiao1,2.1 Institute of Geodesy and Geophysics, chinese {2. of sciences, Wuhan 43.077,{3. 2.Key Laboratory of dynamic geodesy, chinese {2. of sciences, Wuhan 43.077,{3. 3.Graduate University of chinese {2. of sciences, Beijing 100049,{3. Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan 430077 China Key Laboratory of dynamic geodesy Chinese Academy of Sciences Wuhan 430077 China Graduate University of chinese academy of {2.s Beijing 100049 China

The long-term continuous gravity observations obtained by the superconducting gravimeters (SG) at seven globally-distributed stations are comprehensively analyzed. After removing the signals related to the Earth's tides and variations in the Earth's rotation, the gravity residuals are used to describe the seasonal fluctuations in gravity field. Meanwhile, the gravity changes due to the air pressure loading are theoretically modeled from the measurements of the local air pressure, and those due to land water and nontidal ocean loading are also calculated according to the corresponding numerical models. The numerical results show that the gravity changes due to both the air pressure and land water loading are as large as 100×10-9 m s-2.in magnitude, and about 10×10-9 m s-2.for those due to the nontidal ocean loading in the coastal area. On the other hand, the monthly-averaged gravity variations over the area surrounding the stations are derived from the spherical harmonic coefficients of the GRACE-recovered gravity fields, by using Gaussian smoothing technique in which the radius is set to be 600 km. Com-pared the land water induced gravity variations, the SG observations after removal of tides, polar mo-tion effects, air pressure and nontidal ocean loading effects and the GRACE-derived gravity variations with each other, it is inferred that both the ground- and space-based gravity observations can effec-tively detect the seasonal gravity variations with a magnitude of 100×10-9 m s-2.induced by the land water loading. This implies that high precision gravimetry is an effective technique to validate the re-liabilities of the hydrological models.

关键词：重力测量水文模型模型验证和空间地面重力变化季节性波动空气压力

On the local wellposedness of 3.D water wave problem with vorticity

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science china Mathematics 2007年第8期50卷 1065-1077页

作者： Ping ZHANG~1 Zhi-fei ZHANG~2.1 academy of Mathematics and Systems science,{2. academy of sciences,Beijing 100080,china 2.School of Mathematical sciences,Peking University,Beijing 100871,china academy of Mathematics and Systems science Chinese Academy of Sciences Beijing China School of Mathematical sciences Peking University Beijing China

In this article, we first present an equivalent formulation of the free boundary problem to 3.D incompressible Euler equations, then we announce our local wellposedness result concerning the free boundary problem in Sobolev space provided that there is no self-intersection point on the initial surface and under the stability assumption that $\frac{{\partial p}}{{\partial n}}(\xi )\left| {_{t = 0} } \right. \leqslant - 2._0 < 0$ being restricted to the initial surface.

关键词： water-waves free boundary incompressible Euler equations primary 3.Q3. 76B03 secondary 3.J67 3.L80

Stability of proton and maximally symmetric minimal unification model for basic forces and building blocks of matter

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science china(Physics,Mechanics & Astronomy) 2007年第3期50卷 303-310页

作者： WU YueLiang Institute of Theoretical Physics, chinese academy of {2.s, Beijing {3., china Institute of Theoretical Physics Chinese Academy of Sciences Beijing China

With the hypothesis that all independent degrees of freedom of basic building blocks should be treated equally on the same footing and correlated by a possible maximal symmetry, we arrive at a 4-dimensional space-time unification model. In this model the basic building blocks are Majorana fermions in the spinor repre- sentation of 14-dimensional quantum space-time with a gauge symmetry GM4D = SO(1,{2.×SU({2.)×U(1)A×SU({2.F. The model leads to new physics including mirror particles of the standard model. It enables us to issue some fundamental questions that include: why our living space-time is 4-dimensional, why parity is not con- served in our world, how the stability of proton is, what the origin of CP violation is and what the dark matter can be.

关键词： gauge symmetry space-time symmetries beyond standard model and unification

REVIEW OF MIDDLE AND UPPER ATMOSPHERIC RESEARCH IN china

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空间科学学报 1998年第S1期18卷 53-60页

作者： WANG Ying-jian(Center for space science and Applied Researeh,The {2. {3. of sciences, Beijing 100080)

In past two years, the studies of planetary waves, gravity waves, photochemical processes and effects of solar and human activities in china have made encouraging progress. Some new instruments, e.g., VHF radar, sodium lidar,mesospheric microwave measurements and tilting filter photometer etc., have bring into operation, it enhances the observing ability to middle and upper atn1osphere greatly. In this paper main progress of the research in the upper stratosphere, mesosphere and lower thermosphere in china in the past two years is reviewed.

关键词： Middle and upper atmosphere Middle atmospheric dynamics Middle atmospheric photochemistry Atmospheric remote sensing