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The output pulse broadening and enhancement factor with polarization mode dispersion

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The output pulse broadening and enhancement factor with pola...

enhancement factors in Ozone Absorption Based on the Surface Renewal Model and its Application

8～(th) Sino-Japanese Joint Meeting on Optical Fibre Science and Electromagnetic Theory

作者： Yu Zhongyuan Zhang Xiaoguang Liu Yumin Yang HongboSchool of Sciences Beijing University of Posts and Telecommunications 100876 China

＜正＞ We analytically calculate the relation between the initial root-mean-square pulse-width and the output average broadening caused by PMD in optical fiber systems. The optimum of the input pulse-width corresponding to ihe minimal output broadening is derived. In particular, the normalized output bit rates and the PMD enhancement factor are obtained.

关键词： polarization mode dispersion pulse broadening enhancement factor

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Chinese Journal of Chemical Engineering 2000年第3期8卷 236-240页

作者：程江杨卓如陈焕钦 C.H.Kuo M.E.Zappi CollegeofChemicalEnglneering SouthChinaUniversityofTechnologyGuangzhou51（~641~China DepartmentofChemicalEngineering MississippiStateUniversityMS39762StarkvilleUSA

Based on the Danckwerts surface renewal model, a simple explicit expression of the enhancement factor in ozone absorption with a first order ozone self-decomposition and parallel second order ozonation reactions has been derived. The results are compared with our previous work based on the film theory. The 2,4-dichlorophenol destruction rate by ozonation is predicted using the enhancement factor model in this paper.

关键词： enhancement factor ozone absorption surface renewal model

Longitudinal Single Bunch Instability Caused by Wake Field of Electron Cloud

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Chinese Physics Letters 2009年第2期26卷 92-94页

作者：刘瑜冬于程辉 Institute of High Energy Physics Chinese Academy of Sciences PO Box 918 Beijing 100049

The electron cloud accumulated in the vicinity of positron beam generates longitudinal electric field during the passage of bunch. The longitudinal interaction between bunch and electron cloud can lead to the distortion of the bunch shape. We use a simple analytic formula to calculate the longitudinal electric field due to electron cloud. Based on the longitudinal wake field, the macro-particle tracking method is used to simulate the variation of bunch longitudinal profile in different electron cloud densities and the simulation also shows that the synchrotron oscillation tune is slightly shifted by the wake field. By comparing the simulation results and the analytical estimation from potential distortion theory, the longitudinal wake field from electron cloud can be seen as a potential well effect.

关键词： field emission molybdenum dioxide enhancement factor

Analysis of Nanostructural Waveguides Using Fourth-Order Accurate Finite Difference Methods with Nonuniform Scheme

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Chinese Physics Letters 2009年第1期26卷 112-114页

作者：嵇阳恽斌峰胡国华崔一平 Advanced Photonics Center School of Electronic Science and Engineering Southeast University Nanjing 210096

We successfully apply fourth-order accurate finite difference methods with nonuniform scheme to analysis the symmetric slot waveguides. The results of numerical simulations show that the present nonuniform formula off... 详细信息

关键词： field emission molybdenum dioxide enhancement factor

Analytical Investigation of Transmission Properties of Metallic Gratings

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Chinese Physics Letters 2008年第12期25卷 4385-4387页

作者：陈俊学王沛王小蕾鲁拥华郑荣升明海 Department of Physics Anhui Key Laboratory of Optoelectronic Science and Technology University of Science and Technology of China Hefei 230026

We re-examine the classical one-dimensional transmission grating to explain the enhanced transmission in the surface impedance approximation. The nearly zero transmission and extraordinary transmission phenomena related to the surface plasmon are presented by analysing the scattering amplitude of waveguide mode at the output surface of grating. It is revealed that the transmission peaks are related to the Fabry-Perot factor and the interaction of surface plasmon and other diffractive orders.

关键词： field emission molybdenum dioxide enhancement factor

Photonic Crystal Fibre SERS Sensors Based on Silver Nanoparticle Colloid

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Chinese Physics Letters 2008年第12期25卷 4473-4475页

作者：谢志国鲁拥华王沛林开群阎杰明海 Anhui Key Laboratory of Optoelectronic Science and Technology Department of Physics University of Science and Technology of China Hefei 230026

A photonic crystal fibre （PCF） surface enhanced Raman scattering （SERS） sensor is developed based on silver nanoparticle colloid. Analyte solution and silver nanoparticles are injected into the air holes of PCF by a simple modified syringe to overcome mass-transport constraints, allowing more silver nanoparticles involved in SERS activity. This sensor offers significant benefit over the conventional SERS sensor with high flexibility, easy manufacture. We demonstrate the detection of 4-mercaptobenzoic acid （4-MBA ） molecules with the injecting way and the common dipping measurement. The injecting way shows obviously better results than the dipping one. Theoretical analysis indicates that this PCF SERS substrate offers enhancement of about 7 orders of magnitude in SERS active area.

关键词： field emission molybdenum dioxide enhancement factor

Chemical characteristics of aerosols at coastal station in Hong Kong.Ⅱ. Environmental behavior of trace elements during the April 1995 to April 1996

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Journal of Environmental Sciences 2004年第2期16卷 212-221页

作者： K.S.Lam Z.L.Cheng S.C.Kot C.W.Tsang Department of Civil and Structural Engineering the Hong Kong Polytechnic UniversityResearch Center for Eco-Environmental Sciences Chinese Academy of SciencesDepartment of Mechanical Engineering The Hong Kong University of Science & Technology Clear Water BayDepartment of Applied Biology and Chemical Technology the Hong Kong Polytechnic University Hung Hom Hong Kong ChinaBeijing 100085 ChinaHong Kong ChinaHung Hom Hong Kong China

An one-year of sampling aerosol program was carried out during the period of April 1995 to April 1996 at coastal region, Cape D′Aguilar, in Hong Kong. The trace element composition of aerosol particles(TSP and PM 10 ) were measured and analyzed by using the Instrumental Neutron Activation Analysis(INAA) and Inductive Couple Plasma-Mass Spectrometry(ICP-MS) techniques. The results showed that the polluted elements such as: V, Zn, As, Pb, Cd, Sb, I, Se, Bi, with high enrichment factor(E.F) values, are derived from anthropogenic sources, while Sc, Al, Fe, Mn, Sm, La, Sr are less than 10 in E.F, these elements are related the crust and soil. The concentration of the trace elements are present seasonal variation i.e. summer low and winter high, whereas the V or noncrustal V(V *) present summer high and winter low, this phenomenon might be explained by local or regional oil combustion sources. Use three type of elemental ratio, e.g. La/Sm, Mn */V * and Bi/Al indicate that both TSP and PM 10 of La/Sm ratios are mainly related to soil and dust, Mn */V * are probably represent fossil combustion and Bi/Al are possibly associated with refuse incineration, ferromanganese alloys and aluminum production. The varimax rotation factor analysis for trace elements was performed. By means of the absolute principal component analysis(APCA) and multiple regression, the contribution of trace elements to possible sources and overall means of trace elements were estimated. The results showed that the present station is impacted by the anthropogenic species, although the quantities are different during the summertime and wintertime.

关键词： TSP PM 10 trace elements enhancement factor element ratios seasonal variation factor analysis

Correlations between Strong Range Spread-F and GPS L-Band Scintillations Observed in Hainan in 2004

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Chinese Physics Letters 2009年第1期26卷 375-378页

作者：王国军史建魁尚社平王霄 State Key Laboratory of Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100190

Data from the DPS-4 digisonde and the GPS L-band ionospheric scintillation monitor are employed to study the correlations between strong range spread-F （SSF） and GPS L-band scintillations observed in the ionosphere over Hainan Island, China （19.5°N, 109.1°E geogr., dip lat. 9°N） in 2004. The SSF in the ionogram is different from the general range spread-F because it extends in frequency well beyond FoF2 and makes FoF2 difficult to be determined. The observations show that the SSF phenomenon is frequently accompanied by the occurrence of GPS L-band scintillations. The SSF and GPS L-band scintillations occur frequently in the equinoctial months （March, April, September, and October）, but rarely in the winter （January, February, November, and December） and summer （May-August）; especially, occurrence variations of the SSF and GPS L-band scintillations nearly have a same trend. The SSF and scintillations may be associated with the occurrence of topside plasma bubbles and could be explained by the eneralized Rayleigh-Taylor instability.

关键词： field emission molybdenum dioxide enhancement factor

Viscous Cosmology and Thermodynamics of Apparent Horizon

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Chinese Physics Letters 2008年第12期25卷 4199-4202页

作者： M. Akbar Centre for Advanced Mathematics and Physics National University of Sciences and Technology Peshawar Road Rawalpindi Pakistan

It is shown that the differential form of Friedmann equations of Friedman-Robertson-Walker （FRW） universe can be recast as a similar form of the first law ThdSh = dE＋ WdV of thermodynamics at the apparent horizon of FRW universe filled with the viscous fluid. It is also shown that by employing the general expression of temperature Th=｜k｜/2π=1/2π~rA（1-2~rA/2H^rA）associated with the apparent horizon of an FRW universe and assumed that the temperature Tm of the energy inside the apparent horizon is proportional to the horizon temperature Tm=bTh, we are able to show that the generalized second law of thermodynamics holds in the Einstein gravity provided Th-Tm/~rA≤（ρ＋~P）.

关键词： field emission molybdenum dioxide enhancement factor