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Hybrid silicon modulators

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Chinese Optics Letters 2009年第4期7卷 280-285页

作者： J.e.Bowers Department of electrical and Computer engineering University of California Santa Barbara

A number of active elements have been demonstrated using the hybrid silicon evanescent platform, including lasers, amplifiers, and detectors. In this letter, two types of hybrid silicon modulators, flflfilling the building blocks in optical communication on this platform, are presented. A hybrid silicon electroabsorp- tion modulator, suitable for high speed interconnects, with 10-dB extinction ratio at -5 V and 16-GHz modulation bandwidth is demonstrated. In addition, a hybrid silicon Mach-Zehnder modulator utilizing carrier depletion in multiple quantum wells is proved with 2 *** voltage-length product, 150-nm optical bandwidth, and a large signal modulation up to 10 Gb/s.

关键词： Bandwidth electroabsorption modulators Modulation Modulators Optical communication Quantum well lasers Semiconducting indium compounds Semiconductor quantum wells Silicon Silicon detectors

Optical properties of Weyl semimetals

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National Science Review 2019年第2期6卷 206-208页

作者： Joel e.Moore Department of Physics University of California Materials Science Division Lawrence Berkeley National Laboratory

The behavior of electrons in ordinary metals is dominated by physics near the Fermi surface. Indeed, many of the first successes of the quantum theory of solids, such as understanding the large specific heat of metals, followed from applications of the Fermi surface concept. Great effort has been devoted in recent years to semimetals in which the Fermi surface shrinks to a set of Dirac or Weyl points, where four

关键词： As Ta Optical properties of Weyl semimetals

Investigations of the Sheath effect on the Resultant Magnetic Field of a Cylindrical Monopole Plasma Antenna

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Plasma Science and Technology 2015年第2期17卷 153-158页

作者： Moses e.eMeTeRe Department of Physics Covenant University Canaan Land

The functionality of the plasma antenna has been narrowed to types and brand names only. The physics of its operation has been neglected and has stagnated technological innovations. The magnetic field in the sheath and plasma were investigated. Notable specifications were worked out in the proposed improved cylindrical monopole plasma antenna. The occurrence of femto spin demagnetization was discovered between the duration of switch on and switch off of the antenna. This phenomenon seems transient because magnetization is highest at the switch on/off point.

关键词： cylindrical monopole plasma antenna magnetic field size Schr6dinger spin

environmental chemical study on the marsh of Fatimid cemetery at Aswan City, egypt

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Journal of environmental Sciences 2002年第4期14卷 464-473页

作者： M.e.Soltan Chemistry Department Faculty of Science

environmental chemical study were carried out on the Fatimid cemetery marsh at Aswan City(24°1'N and 32°9'e), egypt. Marsh contents(warter, soil, sediment, metal and nonmetal bearing salts, and emergent weed) were analysed to known the source of marsh water, speciation of the different elements between the marsh contents, and the toleration of emergent weed (Phargmites australies) for different metals and their bioaccumulation coefficients. Thus, metals(Ca, Mg, Na, K, Ni, Fe, Mn, Cu, Zn, Cd and Pb) and nonmetals(CO 2- 3, HCO - 3, Cl -, SO 2- 4, PO 3- 4, NO - 3, SiO 2, organic matter and pH value) were determined in the samples. According to the chemical analysis, and applying the base exchange equation(water type) and calculate the hydrochemical parameters for marsh water samples, we can indicate that the marsh water is ground water with Na SO 4 type and deep meteoric genesis. Topsoil of marsh dry land characterized by CaCl as dominant salt,while NaCl is a dominant salt in subsoil. The elevated pH values of marsh contents minimized the metal solubilities in different samples. Phragmites australies showed a strong ability to accumulate Mn and Fe in the aerial part in opposite to Co, Ni and Cd.

关键词： marsh water soil sediment emergent weed egypt

Seven possible states of geospatial data with respect to map projection and definition: a novel pedagogical device for GIS education

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Geo-Spatial Information Science 2018年第4期21卷 288-293页

作者： Steven e.Greco Department of Human ecology University of CaliforniaDavisCAUSA

Conceptually,the theory and implementation of“map projection”in geographic information system(GIS)technology is difficult to comprehend for most introductory students and novice *** this difficulty is the concept of a“map projection file”that defines map projection parameters of geo-spatial *** problem of the“missing projection file”appears ubiquitous for all users,especially in practice where data is widely *** common problem is inadvertent misapplication of the“Define Projection”tool that can result in a GIS dataset with an incorrectly defined map projection *** education should provide more guidance in differentiating the concepts of map projection versus projection files by increasing understanding and minimizing common errors.A novel pedagogical device is introduced in this paper:the seven possible states of GIS data with respect to map projection and *** seven possible states are:(1)a projected coordinate system(PCS)that is correctly defined,(2)a PCS that is incorrectly defined,(3)a PCS that is undefined,(4)a geographic coordinate system(GCS)that is correctly defined,(5)a GCS that is incorrectly defined,(6)a GCS that is undefined,and(7)a *** created automated troubleshooting tools to determine a missing map projection file are discussed.

关键词： GIS education map projection error map projection file define projection

Strategies for creating living, additively manufactured, open-cellular metal and alloy implants by promoting osseointegration,osteoinduction and vascularization: An overview

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Journal of Materials Science & Technology 2019年第2期35卷 231-241页

作者： Lawrence e.Murr Department of Metallurgical Materials and Biomedical Engineering The University of Texas at El Paso W.M.Keck Center for 3D Innovation The University of Texas at El Paso

Additive manufacturing of porous, open-cellular metal or alloy implants, fabricated by laser or electron beam melting of a powder bed, is briefly reviewed in relation to optimizing biomechanical compatibility by assuring elastic(Young's) modulus matching of proximate bone, along with corresponding pore sizes assuring osseointegration and vasculature development and migration. In addition, associated, requisite compressive and fatigue strengths for such implants are described. Strategies for optimizing osteoblast(bone cell) development and osteoinduction as well as vascularization of tissue in 3 D scaffolds and tissue engineering constructs for bone repair are reviewed in relation to the biology of osteogenesis and neovascularization in bone, and the role of associated growth factors, bone morphogenic proteins, signaling molecules and the like. Prospects for infusing hydrogel/collagen matrices containing these cellular and protein components or surgically extracted intramedullary(bone marrow) concentrate/aspirate containing these biological and cell components into porous implants are discussed, as strategies for creating living implants, which over the long term would act as metal or alloy scaffolds.

关键词： Additive manufacturing Open cellular metal and alloy implants electron beam melting Living implant strategies Vascularization Osseointegration Osteoinduction

effect of Cambering on the Aerodynamic Performance of Heaving Airfoils

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Journal of Bionic engineering 2009年第4期6卷 398-404,406-407页

作者： Joel e.Guerrero Postdoctoral Research Fellow Department of CivilEnvironmental and Architectural EngineeringUniversity of GenoaVia Montallegro 1Genoa16145Italy

In the present work,a parametric numerical study is conducted in order to assess the effect of airfoil cambering on the aerodynamic performance of rigid heaving *** incompressible Navier-Stokes equations are solved in their velocity-pressure formulation using a second-order accurate in space and time finite-difference *** tackle the problem of moving boundaries,the governing equations are solved on overlapping structured *** numerical simulations are performed at a Reynolds number of Re=1100 and at different values of Strouhal number and reduced *** results obtained show that the airfoil cambering geometric parameter has a strong influence on the average lift coefficient,while it has a smaller impact on the average thrust coefficient and propulsive efficiency of heaving airfoils.

关键词： heaving airfoils structured overlapping grids incompressible Navier-Stokes equations airfoil cambering

Investigation of genome structure of a cinnamyl alcohol dehydrogenase locus in a basal angiosperm hardwood species, Liriodendron tulipifera L., reveals low synteny

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Journal of Systematics and evolution 2011年第5期49卷 396-405页

作者： Scott e.SCHLARBAUM Department of Forestry Wildlife and FisheriesInstitute of AgricultureThe University of Tennessee

Basal angiosperms contain a wide diversity of floral and growth forms and gave rise to the largest recent angiosperm *** none of the basal angiosperm genomes has been sequenced,examining large bacterial artificial chromosome(BAC) inserts remains the main approach to providing a first glimpse of the structure and organization of their *** this study,we sequenced a 126.9-kbp BAC contig harboring a cinnamyl alcohol dehydrogenase gene(LtuCAD1) in a basal angiosperm species,Liriodendron tulipifera L.,an important timber tree species with significant ecological and economic values.A key enzyme in lignin biosynthesis,CAD catalyzes the final step in the synthesis of *** carried out phylogenetic analyses of seven full-length CAD family genes(LtuCAD1-7) obtained from a comprehensive Liriodendron expressed sequence tag *** phylogenetic tree suggests that LtuCAD1 is the primary CAD gene involved in lignifications as it is the only Liriodendron CAD grouped with the bona fide CADs *** well as the LtuCAD1,the BAC contig contained fragmented sequences for one integrase,eight hypothetical proteins,two gag-pol polyproteins,one RNase H family protein,and one chromatin binding *** analysis with other angiosperm species suggests that the genomic segment in this BAC has undergone frequent *** study is our initial step in identifying and understanding lignin biosynthesis genes from basal angiosperm *** knowledge can help bridge the information gap between hardwood(angiosperm) and softwood(gymnosperm) species and benefit potential breeding and biotechnology application for enhanced production of biomass and digestibility in ***.

关键词： BAC contig cinnamyl alcohol dehydrogenase(CAD) gene order lignin biosynthesis synteny.

High level arsenic resistance in bacteria present in biooxidation tanks used to treat gold-bearing arsenopyrite concentrates:A review

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中国有色金属学会会刊：英文版 2008年第6期18卷 1311-1318页

作者： D.e.RAWLINGS Department of Microbiology University of StellenboschPrivate Bag X1

在连续流动的、搅动的坦克过程使用到金忍受的毒砂集中的对待的微生物引起的协会变得在很多年适应了砷的高集中。主导的微生物， Acidithiobacillus caldus 和 Leptospirillum ferriphilum，被发现包含砷抵抗基因的二个集合。艺术基因... 详细信息

在连续流动的、搅动的坦克过程使用到金忍受的毒砂集中的对待的微生物引起的协会变得在很多年适应了砷的高集中。主导的微生物， Acidithiobacillus caldus 和 Leptospirillum ferriphilum，被发现包含砷抵抗基因的二个集合。艺术基因的一个集合在所有是在场的不管他们是否是，种孤立高度砷抵抗。艺术基因的第二个集合在象 Tn21 一样 transposons 上是在场的并且在测试的所有紧张被发现那被使适应了砷的高集中。在在场的砷抵抗 transposons 在。caldus 和 L。ferriphilum 为他们密切相关，却足够地不同独立地被获得了而非从一个细菌被传递了给其它。transposons 在 escherchia coli 是置换地活跃的并且被显示比测试这是可能的定位 chromosomally 的艺术基因授与砷抵抗的高水平。相同的 Transposons 包含砷抵抗基因或仔细与从 L 的 transposon 有关。ferriphilum，原来在南非发现，也在两 L 被发现。ferrooxidans 和 L。ferriphilum 从南美洲和欧洲孤立。一个 arsB 基因大美人在。caldus 被两个都表明了 chromosomal 艺术基因的能力授与砷抵抗的底层在的相应再结合生产在。caldus 和为猛烈异种的创造的一个基因系统的发展。

关键词：砷电阻因子转座子微生物毒砂