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Origin of.Symmetry Breaking and Conf.nement in Conducting Polymers with Ring Structures

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Communications in Theoretical Physics 2007年第2X期48卷 366-368页

作者： YUAN Yuan Thomas f. George SUN Xin Research Center f.r Quantum Manipulation Fudan University Shanghai 200433 China National Lab of.Inf.ared Physics Shanghai 200083 China Of.ice of.the Chancellor and Center f.r Molecular Electronics Departments of Chemistry & Biochemistry and Physics & Astronomy Univ.ersity of Missouri-St. Louis St. Louis Missouri 63121 USA

A model to describe the main f.atures of.conjugated polymers with ring structures, such as polythiophene and polypyrrole, is constructed. It is shown that the origin of.the symmetry breaking and conf.nement of.a solit... 详细信息

关键词： polymer branch hopping symmetry breaking conf.nement

Can Ebola virus become endemic in the human population？

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Protein & Cell 2016年第1期7卷 4-6页

作者： Gary Wong George f. Gao Xiangguo Qiu Special Pathogens Program National Microbiology Laboratory Public Health Agency of Canada Winnipeg MB CanadaDepartment of Medical Microbiology University of Manitoba Winnipeg MB Canada Department of.Medical Microbiology University of Manitoba Winnipeg MB Canada CAS Key Laboratory of.Pathogenic Microbiology and Immunology Institute of Microbiology Chinese Academy of SciencesBeijing 100101 China National Institute f.r Viral Disease Control and Prevention Chinese Center for Disease Control and PreventionBeijing 100052 China Of.iceof.Director-General Chinese Center for Disease Control and Prevention Beijing 102206 China

The 2014-15 Ebola virus reported during March 2014 Guinea. has shown itself.to （EBOV） outbreak, originally n the Western Af.ican nation of.be resistant to traditional con- tainment methods, with over 28,000 inf.ctions and 11,000 deaths over 18 months. Recently, news that a Scottish nurse had relapsed to EBOV disease with neurological symptoms at 10 months af.er recovery have astonished experts. The prolonged nature of.the outbreak has led to questions whether EBOV can become endemic in the human popula- tion, an undesirable outcome due to the large amount of.resources required to keep this virus under control. In this commentary, we discuss aspects EBOV disease with those caused by pathogens considered endemic in humans, as well as f.ctors which may contribute to sustained EBOV transmission in humans.

关键词： Can Ebola virus become endemic

f.ll-band error control and crack-f.ee surf.ce f.brication techniques f.r ultra-precision f.y cutting of.large-aperture KDP crystals

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f.ontiers of.Mechanical Engineering 2017年第2期12卷 193-202页

作者： f. H. ZHANG S. f. WANG C. H. AN J. WANG Q. XU Department of.Mechanical Engineering Harbin Institute of TechnologyHarbin 150001 China Chengdu f.ne Optical Engineering Research Center Chengdu 610041China

Large-aperture potassium dihydrogen phos- phate （KDP） crystals are widely used in the laser path of.inertial conf.nement f.sion （ICf. systems. The most common method of.manuf.cturing half.meter KDP crystals is ultra-precision f.y cutting. When processing KDP crystals by ultra-precision f.y cutting, the dynamic characteristics of.the f.y cutting machine and f.uctuations in the f.y cutting environment are translated into surf.ce errors at dif.erent spatial f.equency bands. These machin- ing errors should be suppressed ef.ectively to guarantee that KDP crystals meet the f.ll-band machining accuracy specif.ed in the evaluation index. In this study, the anisotropic machinability of.KDP crystals and the causes of.typical surf.ce errors in ultra-precision f.y cutting of.the material are investigated. The structures of.the f.y cutting machine and existing processing parameters are optimized to improve the machined surf.ce quality. The f.ndings are theoretically and practically important in the development of.high-energy laser systems in China.

关键词： ultra-precision f.y cutting large-aperture KDP crystals spatial f.equency processing error

Ef.ects of.Impurity on Microstructure and Hardness in Pure Al Subjected to Dynamic Plastic Def.rmation at Cryogenic Temperature

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Journal of.Materials Science & Technology 2011年第7期27卷 628-632页

作者： f. Huang N.R. Tao K. Lu Shenyang National Laboratory f.r Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

Microstructure and hardness were investigated in pure Al samples with dif.erent purities （5N： 99.999%, 4N： 99.993%, and 2N： 99.7% in weight） subjected to dynamic plastic def.rmation at cryogenic temperatures. The saturated sizes of.ref.ned grains/subgrains in these samples induced by plastic def.rmation are about 240 nm without an obvious impurity ef.ect, but the dislocation density in 2N Al is evidently higher than that in other samples. Boundary misorientations f.r 5N and 4N Al are below 10° with average values of.2–3°, while the average misorientation f.r 2N Al is obviously larger, being about 14°. Microhardness of.LNT-DPD 2N Al is higher than that of.5N and 4N Al, owing to the enhanced dislocation density as their grain/subgrain sizes are almost identical.

关键词： Aluminum Impurity Nanostructure Grain ref.nement

Is maturity index an ef.icient tool to assess the ef.ects of.the physical disturbance on the marine nematode assemblages?—A critical interpretation of.disturbance-induced maturity successions in some study cases in Maldives

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Acta Oceanologica Sinica 2016年第4期35卷 89-98页

作者： SEMPRUCCI f. COLANTONI P. BALSAMO M. Dipartimento di Scienze Biomolecolari (DiSB) Università di Urbino

Maturity index（MI）, based on nematode lif. strategies, has been proposed in 1990 to assess the possible variations of.the terrestrial and f.eshwater nematode assemblages induced by anthropogenic activities. It was subsequently applied also to marine ecosystems and, even if.comparatively not yet very popular, it of.ers a good method to assess the ecological quality in relation to a wide range of.anthropogenic drivers. However, f.w data are available on its response to physical stress, a key f.ctor especially in the coastal areas. In this study, marine nematode genera f.om two study cases carried out in Maldives are used to test both MI and lif. strategy traits（i.e.,c-p classes） f.r detecting the ef.ects of.physical disturbance. The results conf.rm that nematodes are well adapted to physical stress showing a general high rate of.recovery. C-p scaling and MI did not seem to be appropriate f.r revealing this disturbance type probably because there are no empirical evidences on the lif. strategy of.several genera, and a possible dif.erential response to various disturbance types may be hypothesized.

关键词： marine nematodes bioindicators maturity index hydrodynamism tsunami Maldives

Antibacterial and antif.ngal activities of.dif.erent parts of.Tribulus terrestris L. growing in Iraq

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Journal of.Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第2期9卷 154-159页

作者： f.ras A. AL-BAYATI Hassan f. AL-MOLA Department of.Biology College of Education University of Mosul Mosul-00964 Iraq

Antimicrobial activity of.organic and aqueous extracts f.om f.uits, leaves and roots of.Tribulus terrestris L., an Iraqi medicinal plant used as urinary anti-inf.ctive in f.lk medicine, was examined against I l species of.pathogenic and non-pathogenic microorganisms： Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Corynebacterium diphtheriae, Escherichia coli, Proteus vulgaris, Serratia marcescens, Salmonella typhimurium, Klebsiella pneumoniae, Pseudomonas aeruginosa and Candida albicans using microdilution method in 96 multiwell microtiter plates. All the extracts f.om the dif.erent parts of.the plant showed antimicrobial activity against most tested microorganisms. The most active extract against both Gram-negative and Gram-positive bacteria was ethanol extract f.om the f.uits with a minimal inhibitory concentration （MIC） value of.0.15 mg/ml against B. subtilis, B. cereus, P. vulgaris and C. diphtheriae. In addition, the same extract f.om the same plant part demonstrated the strongest antif.ngal activity against C. albicans with an MIC value of.0.15 mg/ml.

关键词： Antimicrobial activity Tribulus terrestris Urinary tract inf.ctions

Magnetic Behaviour of.Sm2Co7/f./Sm2 Co7, Nanocomposite Trilayers with Cr and Ti Additions

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Chinese Physics Letters 2009年第3期26卷 255-257页

作者： f. Shahzad S. A. Siddiqi J. Zhou Advaaced Light Source Berkeley Lab University of California Berkeley CA 94720 USA Centre f.r Solid State Physics University of the Punjab Lahore-54590 Pakistan Department of.Physics University of California Berkeley California 94720 USA

Trilayered Sm2Co7/f./Sm2Co7 spring exchange magnets are f.bricated by dc magnetron sputtering on MgO substrates. Very thin layers （0.3-0.7 nm） of.Cr and Ti are added at the interf.ces of.the two magnetic phases. The thickness of.StucCo7 is kept at 20nm and f. at 6nm while the thickness of.Cr and Ti are varied as 0.3, 0.5, and 0.7nm. The base pressure of.sputtering chamber is kept below 10^-7 Torr and Ar pressure at 3-8m Torr. The samples are characterized by x-ray dif.raction （XRD） and SQUID magnetometer. We report improvement in exchange coupling of.nonacomposite magnets by addition of.thin layers of.Cr at interf.ces.

关键词： MAGNETIC materials MAGNETIC properties COMPOSITE materials LAYER structure (Solids) MICROf.BRICATION NANOSTRUCTURED materials ADDITION reactions SAMARIUM

Ef.ect of.competing solutes on arsenic(Ⅴ) adsorption using iron and aluminum oxides

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Journal of.Environmental Sciences 2007年第8期19卷 910-919页

作者： Youngran Jeong f.N Maohong Johannes Van Leeuwen Joshua f. Belczyk Department of.Civil Construction and Environmental Engineering Iowa State University Ames IA 50011 USA. Center f.r Sustainable Environmental Technology Iowa State University Ames IA 50011 USA Bailey PVS Canonsburg PA 15317 USA

The study f.cused on the ef.ect of.several typical competing solutes on removal of.arsenic with f.2O3 and Al2O3. The test results indicate that chloride, nitrate and sulf.te did not have detectable ef.ects, and that selenium（Ⅳ）（Se（Ⅳ）） and vanadium（Ⅴ）（V（Ⅴ）） showed slight ef.ects on the adsorption of.As（Ⅴ） with f.2O3. The results also showed that adsorption of.As（Ⅴ） on A12O3 was not af.ected by chloride and nitrate anions, but slightly by Se（Ⅳ） and V（Ⅴ） ions. Unlike the adsorption of.As（Ⅴ） with f.2O3, that with f.2O3 was af.ected by the presence of.sulf.te in water solutions. Both phosphate and silica have signif.cant adverse ef.ects on the adsorption of.As（Ⅴ） adsorption with f.2O3 and Al2O3. Compared to the other tested anions, phosphate anion was f.und to be the most prominent solute af.ecting the As（Ⅴ） adsorption with f.2O3 and Al2O3. In general, f.2O3 has a better perf.rmance than Al2O3 in removal of.As（Ⅴ） within a water environment where multi competing solutes are present.

关键词： adsorption arsenic iron oxide aluminum oxide sulf.te selenium(Ⅳ) vanadium(Ⅴ) phosphate silica

Numerical Investigation of.Tip Clearance Ef.ects in an Axial Transonic Compressor

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Journal of.Thermal Science 2012年第2期21卷 109-119页

作者： R. Ciorciari A. Lesser f. Blaim R. Niehuis Institute f.r Jet Propulsion University of Federal Armed Forces Munich Werner-Heisenberg-Weg 39 D-85577 Neubiberg

Numerical investigations of.the Darmstadt transonic single stage compressor (DTC), in the Rotor1-Stator1 conf.guration, aimed at advancing the understanding of.the ef.ect of.dif.erent rotor tip gaps and transition modelling on the blade surf.ces are presented. Steady three dimensional Reynolds Averaged Navier Stokes (RANS) simulations were perf.rmed to obtain the f.ow f.elds f.r the dif.erent conf.gurations at dif.erent operating conditions using the RANS-Solver TRACE. The stage geometry and the multi-block structured grid were generated by G3DMESH and a grid sensitivity analysis was conducted. f.r the clearance gap region, a f.lly gridded special H-grid was chosen. Comparisons were made between the f.ow characteristic at design speed, representative f.r a transonic f.ow regime, and at 65% speed, representative f.r a subsonic f.ow regime. The computations were used to analyse the f.ow phenomena through the tip clearance region f.r the dif.erent conf.gurations and their impact on the perf.rmance of.the compressor stage.

关键词： f.ow in axial compressor surge and stall tip clearance f.ow multimode transition model.