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Exact Periodic-Wave Solutions for(2+1)-Dimensional Boussinesq Equation and (3.1)-Dimensional KP Equation

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Communications in Theoretical Physics 2004年第8期42卷 239-241页

作者： ZHAO Qiang LIU Shi-Kuo FU Zun-Tao school of Physics, peking university, beijing 100871, {3. school of Physics Peking University Beijing 100871 China

The(2+1)-dimensional Boussinesq equation and(3.1)-dimensional KP equation are studied by using theextended Jacobi elliptic-function *** exact periodic-wave solutions for the two equations are obtained.

关键词： Jacobi elliptic-function method (2+l)-dimensional Boussinesq equation (3.l)-dimensional KP equation periodic-wave solutions

A general information theoretical proof for the second law of thermodynamics

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Science china(Physics,Mechanics & Astronomy) 2008年第7期51卷 813-816页

作者： ZHANG QiRen Department of Technical Physics, peking university, beijing 100871, china Department of Technical Physics Peking University Beijing China

It is shown that the conservation and the non-additivity of the information, together with the additivity of the entropy, make the entropy increase in an isolated system. The collapse of the entangled quantum state offers an example of the information non-additivity. Nevertheless, the non-additivity of information is also true in other fields in which the interaction information is important. Examples are classical statistical mechanics, social statistics and financial processes. The second law of thermodynamics is thus proven in its most general form. It is exactly true not only in quantum and classical physics but also in other processes in which the information is conservative and non-additive.

关键词： information conservation non-additivity of information entropy increase

On higher analogues of Courant algebroids

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Science china Mathematics 2011年第3期54卷 437-447页

作者： BI YanHui1 & SHENG YunHe2,3.1Department of Mathematics and LMAM, peking university, beijing 100871, china 2{3. of Mathematics, Jilin university, Changchun 13.012, china 3.3. of Mathematics, Dalian university of Technology, Dalian 116024, china Department of Mathematics and LMAM Peking University Beijing China school of Mathematics Jilin University Changchun China school of Mathematics Dalian University of Technology Dalian China

In this paper, we study the algebraic properties of the higher analogues of Courant algebroid structures on the direct sum bundle TM ⊕∧nT*M for an m-dimensional manifold. As an application, we revisit Nambu-Poisson structures and multisymplectic structures. We prove that the graph of an (n + 1)-vector field π is closed under the higher-order Dorfman bracket iff π is a Nambu-Poisson structure. Consequently, there is an induced Leibniz algebroid structure on ∧nT*M. The graph of an (n+1)-form ω is closed under the higher-order Dorfman bracket iff ω is a premultisymplectic structure of order n, i.e., dω = 0. Furthermore, there is a Lie algebroid structure on the admissible bundle A  ∧nT*M. In particular, for a 2-plectic structure, it induces the Lie 2-algebra structure given in (Baez, Hoffnung and Rogers, 2010).

关键词： higher analogues of Courant algebroids multisymplectic structures Nambu-Poisson structures Leibniz algebroids

Raman OH stretching vibration of ice Ih

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Progress in Natural Science:Materials International 2009年第11期19卷 1651-1654页

作者： Qiang Sun~*,Haifei Zheng The school of Earth and Space Sciences,peking university,beijing 100871,{3. The school of Earth and Space Sciences Peking University Beijing 100871 China

From our recent research on ice Ih(hexagonal ice),we deduce that free OH groups exist at the ice surface and that dangling OH influences the interior of the proton-disordered ***,exploiting recent research by others on water molecular clusters,we propose a new interpretation for the Raman OH stretching vibration of ice *** deconvolute the Raman OH stretching vibration of ice Ihinto four sub-bands,with each sub-band being ascribed to OH vibrations engaged in different types of hydrogen bonding.

关键词： Raman Hydrogen bonding Ice I_h

Progress in cognitive neuroscientific studies of visual awareness

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Progress in Natural Science:Materials International 2009年第2期19卷 145-152页

作者： Qi Li,Haiyan Geng Department of Psychology,peking university,beijing 100871,china Department of Psychology Peking University Beijing 100871 China

The psychological and neural mechanisms of consciousness are among the most baffling problems in cognitive neuroscience. In this field,visual awareness is a topic that has been largely investigated,due to easy manipulation and measurable effects. The present arti-cle begins with the phenomena of dissociations between visual awareness and visual stimulus,visual awareness and visual attention,as well as visual awareness and vision-guided behavior,along with the corresponding experimental evidence. Furthermore,the neural mechanism of visual awareness is also discussed. It has been generally believed that visual awareness is the function of higher-order cerebral areas; however,recent discoveries have demonstrated that feedback from higher-to lower-order cortex areas is necessary for generating consciousness. The present article presents an in-depth analysis regarding this feedback process,and exploring its relation-ship with the generation and mechanisms of consciousness. Finally,theoretical controversies and discrepancies,as well as result con-flicts from various studies,have been collected,compared and discussed. Because the field of consciousness continues to be an extremely mysterious and complicated psychological phenomenon,there is a great need for further studies to explore and clarify this topic.

关键词： Visual awareness Neural mechanism Feedback process Cortical areas

Unbounded Solutions of Almost Periodically Forced Pendulum-Type Equations

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Acta Mathematica Sinica,English Series 2001年第3期17卷 391-396页

作者： Hai HUANG Institute of mathematical Sciences,peking university,beijing 100871.P.R.{3. E-mail:hhjq@*** Institute of mathematical Sciences Peking University Beijing 100871 P. R. China

In this paper,we prove that the forced pendulum-type equation +Gx（x,t）=p（t）,where G（x,t）∈C1（R2） with 1-periodicity in x satisfies the conditions:sup（x,t）∈R2|Gx（x,t）|t→∞{supx∈R|（Gt（x,t））/t|}=0,possesses infinitely many unbounded solutions on a cylinder S1×R for any almost periodic function p（t） with nonvauishing mean value.

关键词： Pendulum-type equation Instability Unbounded solution Almost periodic

What Can the Redshift Observed in EXO 0748-676 Tell Us?

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Chinese Journal of Astronomy and Astrophysics 2003年第1期3卷 33-37页

作者： Ren-Xin XuDepartment of Astronomy, school of Physics, peking university, beijing 100871 rxxu@*** Department of Astronomy School of Physics Peking University Beijing 100871 China

The mass-radius relations for bare and crusted strange stars are calculated with the bag model. Comparing these relations with the observed one derived from the redshift of EXO 0748–676, we come to the conclusion that it is incorrect to say that EXO 0748–676 cannot be a strange star. Various strange star models can show that EXO 0748–676 could have a mass of (1.3.~ 1.7)M☉ and a radius of (8.4 ~ 11.4) km. It is proposed that a proportion of nascent strange stars could be bare and have masses ~ 0.1M☉, and their masses increased over a long period of accretion.

关键词： stars: fundamental parameters dense matter stars: neutron

Implications of micro-compositions of garnet and biotite from high-grade meta-pelites

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Progress in Natural Science:Materials International 2006年第2期16卷 209-214页

作者： ZHOU Xiwen, WEI Chunjing, and ZHANG Shangkun ( Institute of Geology, CAGS, beijing 10003., china school of Earth and Space Sciences, {3., beijing 100871, china china university of Geo-Sciences, beijing 100083. china) Institute of Geology CAGS Beijing 100037 China school of Earth and Space Sciences Peking University Beijing 100871 China china university of Geo-Sciences Beijing 100083 China

Based on detailed studies on the compositional zoning of garnet and biotite in pelitic rocks from the Jingshan group of granulite facies in north Jiaodong, P-T pseudosections with isopleths of Fe/(Fe + Mg) in garnet and biotite were calculated in the KF-MASH system for two representative rocks of sillimanite-garnet-cordierite-biotite gneiss ( Vbi/ Vg>1 ) and sillimanite-garnet gneiss (Vbi/ Vg2) using the software THERMOCALC and the internally consistent thermodynamic dataset. With a comparison of the calculated Fe/(Fe+ Mg) values in garnet and biotite in the peak P-T fields constrained by peak mineral assemblages with the measured ones, it is concluded that the coarse garnet crystals with diffusion zoning from high grade meta-pelites can preserve their peak compositions even when they have experienced a cooling event, and that biotite crystals surrounded by fetsic minerals in biotite-rich rocks with Vbi/Vg> 1 can nearly preserve their peak compositions, and biotites in garnet-rich rocks with Vbi/Vg2 cannot preserve their peak compositions due to the influence of grain-boundary fluid.

关键词： high-grade meta-pelites THERMOCALC P-T pseudosection peak compositions of garnet and biotite.

Towards a degradation-based mechanism for adaptive overload control

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Science china(Information Sciences) 2012年第12期55卷 2708-2722页

作者： WANG ZiYou 1,2,ZHOU MingHui 1,2 & MEI Hong 1,2 1 Software Institute,school of Electronics Engineering and Computer Science,peking university,beijing 100871,{3. 2 Key Laboratory of High Confidence Software Technologies(peking university),Ministry of Education,beijing 100871,{3. Software Institute School of Electronics Engineering and Computer Science Peking University Beijing China Ministry of Education Key Laboratory of High Confidence Software Technologies (Peking University) Beijing China

Uncontrolled overload is one of the major causes of the system's decline in reliability and performance for web *** also harms the construction of trustworthy *** paper presents a degradationbased mechanism to adaptively control overload in complex,dynamic web *** our mechanism,the bottlenecks in the application's performance are determined by internally monitoring the performance and resource utilization state of the application,which is decomposed into a set of *** locating the bottlenecks,two decision algorithms are proposed to dynamically and adaptively generate proper degradation plans without *** degrading the service which consumes critical resources and has a low priority from the perspective of business logic,the application can keep providing key services even when overload *** implement a prototype and conduct a case study on a wiki *** also evaluate our approach and demonstrate its effectiveness in simulated overload *** handling overload,we make a breakthrough in building trustworthy software in an open,dynamic and rapidly changing environment.

关键词： overload service degradation resource monitoring performance management