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Bidirectional Erbium Doped Fiber Amplifiers

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High Technology.Letters 1995年第1期1卷 66-70页

作者： Zhong, c. Peixuan, J. Ling, L. Peida, y. Beijing Univ of Posts and Telecommunications Beijing China

Bidirectional EDFAs(Bi-EDFAs)featuring bidirectional signal input are *** and noise performances of Bi-EDFAs are analy.ed numerically.and comparedwith that of other optical *** of Bi-EDFAs in fiber networks and otherf... 详细信息

关键词： Erbium doped fiber amplifiers ASE Bidirectional optical amplifiers

EFFEcTS OF METAL IONS ON THE cONFORMATIONAL cHANGES OF DNA

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Acta Metallurgica Sinica(English Letters) 2005年第5期18卷 659-663页

作者： G. Q. Liu y. y. Meng S.H. Liu y.H. Hu Laser Life Science Institute South China Normal University Guangzhou 510631China Department of Medical Oncology Cancer Center Sun Yat-sen University of Medical Sciences Guangzhou 510060 China

DNA takes on multi-different conformations such as A-, B-, c-, D- and Z-form. These conformations can transit to one another when DNA deposited in some metal ions solutions or when changing the concentrations of the same metal ions. Here, several major conformational transitions of DNA induced by.metal ions under different environment were introduced and the mechanism of the interaction of metal ions with DNA was discuss in detail.

关键词： DNA conformation transition mechanism condensation

Molecular Dy.amics Simulation of Behaviours of Non-Polar Droplets Merging and Interactions with Hy.rophobic Surfaces

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Journal of Bionic Engineering 2008年第4期5卷 271-281页

作者： y.y. y.n c.y. Ji School of the Built Environment University of Nottingham Nottingham NG7 2RD UK

This paper presents a molecular dy.amics simulation of the behaviours of non-polar droplets merging and also the fluid molecules interacting with a hy.rophobic surface. Such behaviours and transport phenomena are popular in general microchannel flow boiling and two-phase flow. The droplets are assumed to be composed of Lennards-Jones ty.e molecules. Periodic boundary.conditions are applied in three coordinate directions of a 3-D sy.tem, where there exist two liquid droplets and their vapour. The two droplets merge when they.come within the prescribed small distance. The merging of two droplets apart from each other at different initial distances is tested and the possible larger （or critical） non-dimensional distance, in which droplets merging can occur, is discussed. The evolution of the merging process is simulated numerically.by.employ.ng the Molecular Dy.amics （MD） method. For interactions with hy.rophobic solid wall, a sy.tem with fluid confined between two walls is used to study.the wetting phenomena of fluid and solid wall. The results are compared with those of hy.rophilic wall to show the unique characteristics of hy.rophobic interactions by.microscopic methods.

关键词： molecular dy.amics simulation mist flow droplets merging hy.rophobic wetting

Deflecting Easy.axis of Fe_3O_4 Single cry.tal Nanowires by.Magnetic-field-induced Method

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Journal of Materials Science & Technology 2012年第11期28卷 976-980页

作者： W. Wang S. y. Wang college of Phy.ics and Technology Nanjing Normal University Nanjing 210046 China School of Transportation Southeast University Nanjing 210096 China

In order to control the orientation of easy.axis of magnetic nanowires, FesO4 single cry.tal nanowires with easy.axis perpendicular to wire-axis were prepared successfully.by.means of a magnetic-field-induced method. Analy.is of X-ray.diffraction and electron diffraction pattern showed that there was a wide-angle deflection of easy.axis in the prepared Fe304 nanowires. A high saturation magnetization （82 emu/g） of the FesO4 nanowires was achieved at room temperature. The benefits and mechanism of the deflection of easy.axis from its wire-axis in FesO4 single cry.tal nanowires were discussed. The results are expected to broaden the magnetic properties of traditional ferrite nanowires.

关键词： Magnetic-field-induced Fea04 nanowire Easy.axis

Positron-Lithium Atom and Electron-Lithium Atom Scattering Sy.tems at Intermediate and High Energies

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chinese Phy.ics Letters 2006年第7期23卷 1753-1756页

作者： K. Ratnavelu S. y. Ng Institute of Mathematical Sciences Faculty of Science University of Malaya 50603 Kuala Lumpur Malaysia Department of Phy.ics Faculty of Science National University of Singapore Singapore

The coupled-channel optical method is used to study.positron scattering by.atomic lithium at energies ranging from the ionization threshold to 60eV, The present method simultaneously.treats the target channels and the positronium （Ps） channels in the coupled-channel method together with the continuum effects via an ab-initio optical potential. Ionization, elastic and inelastic cross sections in target channels, and the total cross section are also reported and compared with other theoretical and experimental data. A comparative study.with the corresponding electron-lithium data is also reported.

关键词： cLOSE-cOUPLING THEORy Hy.ROGEN ScATTERING cROSS-SEcTIONS cOLLISIONS

NUMERIcAL ANALy.IS OF THE INFLUENcE OF THE TIP cLEARANcE FLOWS ON THE UNSTEADy.cAVITATING FLOWS IN A THREE- D IMENSIONAL INDUcER

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Journal of Hy.rody.amics 2009年第1期21卷 34-40页

作者： OKITA K. UGAJIN H. MATSUMOTO y. RIKEN Saitama 351-0198 Japan IHI corporation Yokohama 235-8501 Japan Department of Mechanical Engineering The University of TokyoTokyo 113-8656 Japan

To clarify.the influences of the tip clearance flows on the unsteady.cavitating flow, the three-dimensional unsteady.cavitating flows through both the two-dimensional cascades and the three-dimensional inducer with and without tip clearance are performed numerically. The governing equations for the compressible fluid flow with the DES turbulence model are employ.d with the assumption of the isentropic process of liquid phase. The evolution of cavities is represented as the source/sink of vapor phase. The basic equations in the curve linear coordinate are solved by.the finite difference method. As the results of the three-dimensional cavitating flows through the two-dimensional cascades, the tip clearance flows from the pressure side to the suction side of the blade produces the tip vortex cavitation, which affects the sheet cavitation on the leading edge of the next blade and enhances the blockage effect near the casing than the flows without tip clearance. On the other hand, in the case of the three-dimensional inducer, the large backflow cavitation is observed around the inlet of the inducer, where the cavities are developed on the casing by.the tip clearance flows. The large pressure gradient between the non-cavitating pressure side and the cavitating suction side enhances the tip clearance flows. The calculation considering the tip clearance reproduces the developed cavitation region similar to that of experimental visualizations. Additionally. the backflow cavitation rotates with the speed slower than the rotation speed of the inducer. Then, the rotation of backflow cavitation causes the periodic fluctuation of the outlet pressure greater than that of the inlet pressure.

关键词： cavitation inducer tip clearance flow numerical analy.is

A model of regional economic development with increasing returns

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Journal of Zhejiang University.Science A(Applied Phy.ics & Engineering) 2007年第1期8卷 164-170页

作者： QIAN Edward y. y.O y.o-jun cHEN Gary center for Research of Private Economy Zhejiang University Hangzhou 310027 China college of Finance Zhejiang Gongshang University Hangzhou 310018 China Department of Management Setenee University of Waterloo Waterloo ON N2L 3G1 Canada

This paper develops mathematically.and empirically.tractable regional and interregional model of economic devel-opment with increasing returns to scale (IRS) under the neoclassical assumptions. A one-sector, two-region model in which one region exhibits IRS is presented and the whole nation presents constant returns to scale. The development of the local IRS economy.is shown to be constrained to a “moving equilibrium” path. The preliminary.empirical results are sufficiently.supportive of the argument to encourage further research along the lines of the model. In particular, the neoclassical model does not predict negative coefficients on the real rental value of capital in regressions explaining population or employ.ent relative to that in the nation.

关键词： Economic development Increasing returns Moving equilibrium

Methoprene does not affect juvenile hormone titers in honey.bee （Apis mellifera） workers

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Insect Science 2018年第2期25卷 235-240页

作者： Zachary.y. Huang Stephanie Lin Kiheung Ahn Department of Entomology Michigan State University East Lansing Michigan USA Ecology Evolutionary Biology and Behavior Michigan State University East Lansing Michigan USA BEAcON center for the Study.of Evolution in Action Michigan State University East Lansing Michigan USA and 4High School Honors Science Program 2007 Michigan State University East Lansing Michigan USA

Methoprene, a juvenile hormone （JH） analog, is a widely.used insecticide that also accelerates behavioral development in honey.bees （Apis mellifera）. JH regulates the transition from nursing to foraging in adult worker bees, and treatment with JH or methoprene have both been shown to induce precocious foraging. To determine how methoprene changes honey.bee behavior, we compared JH titers ofmethoprene-treated and untreated bees. Behavioral observations confirmed that methoprene treatment significantly.increased the number of precocious foragers in 3 out of 4 colonies. In only.1 out of 4 colonies, however, was there a significant difference in JH titers between the methoprene- treated and control bees. Further, in all 4 colonies, there was no significant differences in JH titers between precocious and normal-aged foragers. These results suggest that methoprene did not directly.affect the endogenous JH secreted by.corpora allata. Because methoprene caused early.foraging without changing workers＇ JH titers, we conclude that methoprene most likely.acts directly.on the JH receptors as a substitute for JH.

关键词： behavioral development juvenile hormone analog juvenile hormone metho-prene precocious foraging

Attuned design of demand response program and M-FAcTS for relieving congestion in a restructured market environment

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Frontiers in Energy 2015年第3期9卷 282-296页

作者： y. HASHEMI H. SHAy.GHI B. HASHEMI Technical Engineering Department University of Mohaghegh Ardabili Ardabil *** Iran Network Studies Group Bakhtar Regional Electric Company Arak *** Iran

This paper addresses the attuned use of multi- converter flexible alternative current transmission sy.tems （M-FAcTS） devices and demand response （DR） to perform congestion management （cM） in the deregulated environment. The strong control capability.of the M- FAcTS offers a great potential in solving many.of the problems facing electric utilities. Besides, DR is a novel procedure that can be an effective tool for reduction of congestion. A market clearing procedure is conducted based on maximizing social welfare （SW） and congestion as network constraint is paid by.using concurrently.the DR and M-FAcTS. A multi-objective problem （MOP） based on the sum of the pay.ents received by.the generators for changing their output, the total pay.ent received by.DR participants to reduce their load and M-FAcTS cost is sy.tematized. For the solution of this problem a nonlinear time-vary.ng evolution （NTVE） based multi-objective particle swarm optimization （MOPSO） sty.e is formed. Fuzzy.decision-making （FDM） and technique for order preference by.similarity.to ideal solution （TOPSIS） approaches are employ.d for finding the best compromise solution from the set of Pareto-solutions obtained through multi-objective particle swarm optimization-nonlinear time-vary.ng evolution （MOPSO-NTVE）. In a real power sy.tem, Azarbaijan regional power sy.tem of Iran, comparative analy.is of the results obtained from the application of the DR ＆ unified power flow controller （UPFc） and the DR ＆ M-FAcTS are presented.

关键词： multi-converter flexible alternative currenttransmission sy.tems (M-FAcTS) demand response,