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Intermediate processes and critical phenomena: Theory, method and progress of fractional operators and their applications to modern mechanics

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Science China(physics,Mechanics & Astronomy) 2006年第3期49卷 257-272页

作者： XU Mingyu1 & TAN Wenchang2 1. Institute of Applied Mathematics, School of Math & System Science, Shandong university, Jinan 250100, China 2. State Key Laboratory of Turbulence and Complex Systems & department of Mechanics and Engineering Science, peking university, beijing 100871, China 1. Institute of Applied Mathematics School of Math & System Science Shandong University Jinan 250100 China 2. State Key Laboratory of Turbulence and Complex Systems & department of Mechanics and Engineering Science Peking University Beijing 100871 China

From point of view of physics, especially of mechanics, we briefly introduce fractional operators (with emphasis on fractional calculus and fractional differential equa- tions) used for describing intermediate processes and critical phenomena in physics and mechanics, their progress in theory and methods and their applications to modern me- chanics. Some authors’ researches in this area in recent years are included. Finally, prospects and evaluation for this subject are made.

关键词： fractional operators,intermediate processes,critical phenomena,modern mechanics

^(234.Th/^(238)U disequilibrium and particulate organic carbon export in the northwestern South China Sea

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Acta Oceanologica Sinica 2011年第3期30卷 55-62页

作者： MA Hao ZENG Zhi YU Wen HE Jianhua CHEN Liqi CHENG Jianping YIN Mingduan ZENG Shi department of Engineering physics Tsinghua University Beijing 100084 China Key Laboratory of Global Change and Marine-atmospheric Chemistry State Oceanic Administration Xiamen 361005 China Key Laboratory of Particle ＆ Radiation Imaging （Tsinghua university） Ministry of Education Beijing 100084 China Key Laboratory of High Energy Radiation Imaging Fundamental Science for National Defense Beijing 100084 China

234.h was utilized as a tracer of particulate organic carbon （POC） export in the northwestern South China Sea （SCS） on the basis of the data collected at four stations during a spring cruise. Depth profiles of dissolved and particulate 234.h activities were measured in the upper 60m, showing a significant deficit relative to 23Su over the investigated stations. A stratified structure of 234.h-23su disequilibrium was in general observed in the upper 60 m water column, indicating that the euphotic zone of the northwestern SCS in this reason can be divided into two layers, an upper and lower layer, with different export rates. POC export fluxes were estimated from a one-dimensional steady state model of 234.h fluxes in combination with the measurement of POC/234.h ratios on suspended particles. The POC export in this region ranged from 8.2 to 20.0 mmol/（m2.d）, with an average of 16.0 mmol/（m2-d）, and was slightly higher than those previously reported in the southern SCS.

关键词： 234.h 23su disequilibrium POC export South China Sea

Doping-free carbon nanotube optoelectronic devices

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Science Bulletin 2012年第Z1期 149-156页

作者： WANG Sheng*,ZHANG ZhiYong & PENG LianMao* Key Laboratory for the physics and Chemistry of Nanodevices,department of Electronics,peking university,{4. 100871,China

Semiconducting carbon nanotubes(CNTs) possess outstanding electrical and optical properties because of their special one-dimen-sional(1D) *** are direct bandgap materials,which makes them ideal for use in optoelectronic devices,*** emitters and light *** determine their light absorption and light emission processes due to the strong Coulomb interactions between electrons and holes in *** this paper,we review recent progress in CNT photodetectors,photovoltaic devices and light *** particular,we focus on the doping-free CNT optoelectronic devices developed by our group in recent years.

关键词： carbon nanotube diode photodetector LED solar cell doping-free

High-performance doping-free carbon-nanotube-based CMOS devices and integrated circuits

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Science Bulletin 2012年第Z1期 135-148页

作者： ZHANG ZhiYong*,WANG Sheng & PENG LianMao Key Laboratory for the physics and Chemistry of Nanodevices and department of Electronics,peking university,{4. 100871,China

Ballistic n-type carbon nanotube(CNT)-based field-effect transistors(FETs) have been fabricated by contacting semiconducting single-walled CNTs(SWCNTs) using Sc or *** n-type CNT FETs were pushed to their performance limits through further optimizing their gate structure and *** CNT FETs outperformed n-type Si metal-oxide-semiconductor(MOS) FETs with the same gate length and displayed better downscaling behavior than the Si MOS *** with the demonstration of ballistic p-type CNT FETs using Pd contacts,this technological advance is a step toward the doping-free fabrication of CNT-based ballistic complementary metal-oxide-semiconductor(CMOS) devices and integrated *** full advantage of the perfectly symmetric band structure of the semiconductor SWCNT,a perfect SWCNT-based CMOS inverter was demonstrated,which had a voltage gain of over *** adjacent n-and p-type FETs fabricated on the same SWCNT with a self-aligned top-gate realized high field mobility simultaneously for electrons(3000 cm2 V-1 s-1) and holes(3300 cm2 V-1 s-1).The CNT FETs also had excellent potential for high-frequency applications,such as a high-performance frequency doubler.

关键词： carbon nanotube field-effect transistor doping-free complementary metal-oxide-semiconductor high frequency

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不确定关系的经典类比

物理学报 1996年第3期45卷 353-359页

作者：黄湘友北京大学物理系北京100871

与量子力学不确定关系相类似的关系在经典力学中也存在。利用这关系计算了几个具体实例。从计算中可看出一个波函数经典极限下只能描述系综。

关键词：不确定关系量子力学经典力学

Random walk modeling of wake dispersion for the exhaust tower of an underground tunnel in urban area

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Journal of Environmental Sciences 1999年第4期11卷 474-479页

作者： JIANG Wei\|mei\+1, YU Hong\|bin\+1, LI Xin\+2 (1.department of atmospheric Sciences, Nanjing university, Nanjing 210093, China 2.LAPC, Institute of atmospheric{4.,Chinese Academy of Sciences, beijing 100029, China) department of atmospheric Sciences Nanjing University Nanjing 210093 China LAPC Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

In this paper, some experimental studies on the impact of effluent from an exhaust tower of an underground tunnel with special construction are reported. By measuring the flow field downstream of the tower in NJU meteorological wind tunnel, some flow characteristics in the make area were established. Based on these, an advanced random\|walk dispersion model was set up and applied successfully to the simulation of dispersion in the wake area. The modelling results were in accordance with wind tunnel measurements. The computed maximum of ground surface concentration in the building case was a factor of 3-4.higher than that in the flat case and appeared much closer to the source. The simulation indicated that random walk modelling is an effective and practical tool for the wake stream impact assessment.

关键词： exhaust tower air pollution in urban area atmospheric dispersion random walk modelling

THE SOLVABILITY FOR A CLASS OF SINGULARLY PERTURBED QUASI-LINEAR DIFFERENTIAL SYSTEM

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Acta Mathematica Scientia 2008年第3期28卷 495-500页

作者：莫嘉琪王辉林万涛 department of Mathemtics Anhui Normal University Division of Computational Science E-Institutes of Shanghai Universities at SJTUShanghai 200240China department of Mathematics Huzhou Teachers'CollegeHuzhou 313000China Chinese Academy of Meteorological Sciences LASG Institute of Atmospheric PhysicsChinese Academy of Sciences

The solvability for a class of singularly perturbed Robin problem of quasilinear differential system is considered. Using the boundary layer corrective method the formal asymptotic solution is constructed. And using t... 详细信息

关键词： Solvability singular perturbation differential system boundary layer

Nonfactorizable B→xc0K Decay and QCD Factorization

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Communications in Theoretical physics 2007年第11期48卷 885-890页

作者： MENG Ce~1 GAO Ying-Jia~1 CHAO Kuang-Ta~(1,2)1 department of physics,peking university,{4. 100871,China2 China Center of Advanced Science and Technology (World Laboratory),{4. 100080,China

We study the unexpectedly large rate for the factorization-forbidden decay B→xK within the QCDfactorization *** use a non-zero gluon mass to regularize the infrared divergences in vertex ***-point singularities arising from spectator corrections are regularized and carefully estimated by the off-shellness *** find that the contributions arising from the vertex and leading-twist spectator corrections are numericallysmall,and the twist-3 spectator contribution with chiral enhancement and linear end-point singularity becomes *** reasonable choices for the parameters,the branching ratio for B→xK decay is estimated tb be in the range(2～4.×10,which is compatible with the Belle and BaBar data.

关键词： B meson decay QCD factorization charmonium

A quantification model for apoptosis in mouse embryos in the early stage of fetation

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Science China(Life Sciences) 2009年第10期52卷 922-927页

作者： WANG PengFei1, FU JianHua1, MA WanYun1, CHEN DieYan1, Lü DanYu2 & BAI WenJia3 1 Key Laboratory for Atomic and Molecular Nanosciences of Education Ministry, department of physics, Tsinghua university, beijing 100084. China 2 department of Anatomy & Histology and Embryology, School of Basic Medical Sciences peking university Health Science Center, beijing 100083, China 3 department of Automation, Tsinghua university, beijing 100084. China 1. Key Laboratory for Atomic and Molecular Nanosciences of Education Ministry Department of Physics Tsinghua University Beijing 100084 China 2. department of Anatomy & Histology and Embryology School of Basic Medical Sciences Peking University Health Science Center Beijing 100083 China 3. department of Automation Tsinghua University Beijing 100084 China

Apoptosis is the most important inducement and modulator for embryos in the early stage of fetation, i.e. after the 8-cell stage, mostly the morula and blastula stage, to proceed to the stage of nonlinear development. Using a two-photon laser scanning microscopy (TPLSM) system, we obtained 3-dimensional (3D) fluorescent images of preimplantation mouse embryos. A model for quantification was established. The statistical results for the spatial location of apoptosis bodies in embryos was obtained following image processing, as well as investigation of the kinetics of apoptosis. It was found that most (70%) apoptosis occurred in the trophectoderm, and the departure between the centroid and geometric center of embryos had a step transition when embryos developed into the 32-cell stage, which was consistent with the theoretical prediction that the blastocele would induce a symmetry break of the distribution of cells in embryos.

关键词： apoptosis preimplantation mouse embryo TPLSM quantification model