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journal of Thermal Science 2012年第1期21卷 49-59页

作者： C. Azih j.r. Brinkerhoff m.I. Yaras Department of mechanical and Aerospace Engineering Carleton University

Experimental research has long shown that forced-convective heat transfer in wall-bounded turbulent flows of fluids in the supercritical thermodynamic state is not accurately predicted by correlations that have been developed for single-phase fluids in the subcritical thermodynamic state. In the present computational study, the statistical properties of turbulent flow as well as the development of coherent flow structures in a zero-pressuregradient flat-plate boundary layer are investigated in the absence of body forces, where the working fluid is in the supercritical thermodynamic state. The simulated boundary layers are developed to a friction reynolds number of 250 for two heat-flux to mass-flux ratios corresponding to cases where normal heat transfer and improved heat transfer are observed. In the case where improved heat transfer is observed, spanwise spacing of the near-wall coherent flow structures is reduced due to a relatively less stable flow environment resulting from the lower magnitudes of the wall-normal viscosity-gradient profile.

关键词： boundary layer turbulence supercritical fluids improved heat transfer DNS

Germination strategies of annual and short-lived perennial species in the Arabian Desert

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journal of Arid Land 2020年第6期12卷 1071-1082页

作者： Arvind BHATT David j GALLACHEr Paulo r m SOUZA-FILHO Lushan Botanical Garden Chinese Academy of SciencesJiujiang 332900China School of Life and Environmental Sciences The University of SydneyNarrabri NSW 2390Australia multidisciplinary Center of Barra Federal University of Western BahiaBarra 47100-000Brazil

Germination timing is highly regulated in short-lived plant species since it strongly influences recruitment success of *** deserts,the spatiotemporal distribution of plant-available water is highly episodic and unpredictable,making winter months more favorable for seed germination when other abiotic conditions *** hypothesized that changes in photoperiod and thermoperiod would impact germination more in seeds that had undergone in situ *** assessed 21 annual and short-lived perennial species in the Arabian Desert to find(1)if seeds were dormant at maturity,(2)if in situ seed storage increased germination percentage compared with no storage,(3)if photoperiod and thermoperiod germination requirements were influenced by in situ storage,and(4)if a phylogenetic association in seed germination could be *** of each species collected in early 2017 were divided into two *** was tested for germination within one week(fresh seeds).The other was stored in situ at the maternal location(stored seeds)until October 2017 and tested for seed germination in the first week of *** germination was conducted in incubators at two thermoperiods(15℃/20℃ and 20℃/30℃;12 h/12 h),and two photoperiods(12 and 0 h light per day).results indicated that seed germination percentages of 13 species were significantly enhanced by in situ storage.A thermoperiod response was exhibited by stored,but not fresh *** exposure increased germination of fresh seeds but had only a minimal effect on stored *** traits exhibited no phylogenetic *** result indicated that selection pressure for germination strategy was stronger than that for taxonomic traits of these desert species.

关键词： desert species dormancy germination light temperature phylogeny

Structural Ultrafine Grained Steels Obtained by Advanced Controlled rolling

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journal of Iron and Steel research International 2013年第1期20卷 62-70页

作者： r González j O García m A Barbés m j Quintana L F Verdeja j I Verdeja School of Engineering Panamerican UniversityMexico City 03920Mexico E T S I m O Oviedo UniversityOviedo 33004Spain

Steels with ultrafine grains （lower than 5 μm）, which usually known as ultrafine ferrite or ultrafine grained materials, are presently the object of intense research, because of the improvement in resistance and fracture toughness they may reach compared to conventional steels （with grain sizes above this value）. It is shown that the forenamed steels designated in the Euronorm EN 10149-2, which are manufactured by advanced techniques of controlled rolling and mainly used in automotive industry, have an ultrafine grain size in the range of 2.5 to 3.5 μm, and with elastic yield stresses higher than 400 mPa. Based on the morrison-miller criterion, it is shown that values of the strain-hardening coefficient lower than 0.08 would make the industrial application of these steels unfeasible.

关键词： ultrafine grained steel mechanical property manufacturability strain-hardening

Ultrafine Grained HSLA Steels for Cold Forming

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journal of Iron and Steel research International 2010年第10期17卷 50-56页

作者： r González j O García m A Barbés m j Quintana L F Verdeja j I Verdeja School of Engineering Panamerican University ETSImO Oviedo University

The industrial level production of ultrafine grained （or ultrafine ferrite） ferrous alloys was investigated through three examples of steels that complied with the EN 10149-2 Euronorm and were produced by advanced con- trolled hot rolling techniques. The steel samples were tension tested and chemically analyzed, and the microstructure was evaluated through quantitative metallographic techniques to determine parameters such as yield stress, amount of microalloying elements, strain hardening coefficient, grain size, and grain size distribution. These steels were micro- alloyed with Ti, Nb, and mn with ASTm grain sizes of approximately 13--15. The careful control of chemical com- position and deformation during production, giving a specific attention to the deformation sequences, austenite non- reerystallization temperatures and allotropic transformations during cooling, are indispensable to obtain steels with an adequate strain hardening coefficient that allows cold working operations such as bending, stretching or drawing.

关键词： ultrafine steel metallography strain hardening Euronorm

Preparation of Amorphous Film on Ni-S Alloy by Electroplating method

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Chinese Chemical Letters 1998年第11期9卷 0-0,0-0页

作者： Du m. Gao r.j. Wei X.j. Ocean Univ Qingdao Coll Chem & Chem Engn Qingdao 266003 Peoples R China NE Univ Technol Dept Nonferrrous Met Shenyang 110006 Peoples R China

Beginning from the formation of amorphous alloy film and its use of proAnse, this paper obtains the Ni-S amorphous alloy film by electroplating method using a bath containing Na2S2O3, and considers the deposition conditions in detail. The composition of Ni-S alloy film changes with the cathodic current density, Na2S2O3 content in the bath solution and bath pH, but the structure of the film is detendned by the sulphur content in the deposit. X-ray diffraction (XrD) patterns show that films containing about 15-30% sulphur consist of amorphous alloy. In addition, the process of Ni-S alloy film deposition and the relation between the plating conditions and deposits were studied.

关键词： Ni-S alloy electroplating amorphous structure

mineral dust resuspension under vibration: Onset conditions and the role of humidity

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Particuology 2020年第3期18卷 112-119页

作者： F.j.Balladore j.G.Benito r.O.Unac A.m.Vidales Departamento de mineria Facultad de Ciencias Fisico Matematicas y NaturalesUniversidad Nacional de San LuisChacabuco 917D5700HHWSan LuisArgentina INFAP CONICETDepartamento de FisicaFacultad de Ciencias Fisico Matematicas y NaturalesUniversidad Nacional de San LuisEjercito de los Andes 950D5700HHWSan LuisArgentina

The vibration of dusty surfaces inevitably causes re-entrainment of particles into the *** that movement of mineral dust particles deposited on a surface begins at a critical frequency (fc) and amplitude,an experimental laboratory study was conducted to determine the onset conditions for resuspension of a vibrated granular *** determined the resuspension state diagram as a function of frequency and amplitude of a sinusoidal vibration,the granulometry of the dust and the thickness of the soil *** mitigation effect of humidity was also *** frequencies ranged between 2.5 and 23 Hz when amplitudes were less than 12 *** results were independent of bed thickness and perturbation *** all particle sizes observed,fc decreased monotonically with A,contrasting with behavior observed for individual *** dry samples,fe for large size classes was markedly less when A was greater than 6 mm;while thefc for fine fractions only decreased once amplitudes reached 10 *** with wet granular soils demonstrated that wetting above an optimum humidity did not necessarily impede movement and caused *** study provides guidelines for managing resuspension of granular soils subjected to vibrations.

关键词： resuspension Vibration Granular soil mineral dust Critical frequency Humidity

Optimization of performance of the Km2A full array using the Crab Nebula

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Chinese Physics C 2024年第6期48卷 169-178页

作者：曹臻 F.Aharonian 安琪阿西克古白云翔包逸炜 D.Bastieri 毕效军毕玉江蔡金庭曹晴曹文羽曹喆常进常劲帆陈尚明陈恩生陈亮陈林陈龙陈明君陈玛丽陈起辉陈素弘陈天禄陈阳程宁程耀东崔明阳崔树旺崔晓红崔昱东戴本忠代洪亮戴子高单增罗布 D.della Volpe 董绪强段凯凯樊军辉范一中方军方堃冯存峰封莉冯少辉丰晓婷冯有亮 S.Gabici 高博高川东高林青高启高卫高伟康葛茂茂耿利斯 G.Giacinti 龚光华苟全补顾旻皓郭福来郭晓磊郭义庆郭莹莹韩毅昂何会海贺昊宁何佳银何新波何钰 m.Heller 贺远强侯博文侯超侯贤胡红波胡铨胡世聪黄代绘黄天奇黄文俊黄性涛黄晓渊黄勇黄志成季筱璐贾焕玉贾康江琨姜晓巍姜泽军金敏康明铭柯通 D.Kuleshov.K.Kurinov 李兵兵李澄李骢李丹李飞李海波李会财李华阳李军李剑李捷李凯李文龙李文莲李秀荣李昕李一卓李哲黎卓梁恩维梁云峰林苏杰刘冰刘成刘栋刘虎刘海东刘佳刘江来刘金艳刘茂元柳若愚刘四明刘伟刘怡刘以农鲁睿罗晴吕洪魁马伯强马玲玲马欣华毛基荣闵振 W.mitthumsiri 穆慧君南云程 A.Neronov 区子维庞彬宇 P.Pattarakijwanich 裴致远齐孟尧祁业情乔冰强秦家军 D.ruffolo A.Sáiz D.Semikoz 邵澄宇邵琅 O.Shchegolev 盛祥东舒富文宋慧超 Yu.V.Stenkin V.Stepanov 苏扬孙秦宁孙晓娜孙志斌谭柏轩唐庆文唐泽波田文武王超王昌贝王广威王洪光王惠惠王建成汪凯王利苹王玲玉王培汉王冉王为王祥高王祥玉王阳王玉东王岩谨王忠海王仲翔王振王铮韦大明魏俊杰魏永健文韬吴超勇吴含荣武莎吴雪峰吴雨生席邵强夏捷夏君集项光漫肖迪泫肖刚辛广广辛玉良邢祎熊峥徐东莲徐仁峰徐仁新徐伟立薛良闫大海颜景志颜田杨朝文杨帆杨冯帆杨何文杨佳盈杨莉莉杨明洁杨睿智杨深邦姚玉华姚志国叶一锰尹丽巧尹娜游晓浩游智勇于艳红袁强岳华曾厚敦曾婷轩曾玮查敏张彬彬张丰张海明张恒英张建立张丽霞张力张鹏飞张佩佩张瑞张少博张少如张寿山张潇张笑鹏张云峰张毅张勇赵兵赵静赵雷赵立志赵世平郑福周斌周浩周佳能周猛周平周荣周勋秀祝成光祝凤荣朱辉朱科军左雄 LHAASO Collaboration Key Laboratory of Particle Astrophyics&Experimental Physics Division&Computing Center Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China Tianfu Cosmic ray research Center Chengdu 610000China Dublin Institute for Advanced Studies 31 Fitzwilliam Place2 DublinIreland max-Planck-Institut for Nuclear Physics P.O.Box 10398069029 HeidelbergGermany State Key Laboratory of Particle Detection and Electronics China University of Science and Technology of China Hefei 230026China School of Physical Science and Technology&School of Information Science and Technology Southwest Jiaotong UniversityChengdu 610031China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China Center for Astrophysics Guangzhou UniversityGuangzhou 510006China Hebei Normal University Shijiazhuang 050024China Key Laboratory of Dark matter and Space Astronomy&Key Laboratory of radio Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023China Tsung-Dao Lee Institute&School of Physics and Astronomy Shanghai Jiao Tong UniversityShanghai 200240China Key Laboratory for research in Galaxies and Cosmology Shanghai Astronomical ObservatoryChinese Academy of SciencesShanghai 200030China Key Laboratory of Cosmic rays(Tibet University) Ministry of EducationLhasa 850000TibetChina National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China School of Physics and Astronomy(Zhuhai)&School of Physics(Guangzhou)&Sino-French Institute of Nuclear Engineering and Technology(Zhuhai) Sun Yat-sen UniversityZhuhai 519000&Guangzhou 510275China School of Physics and Astronomy Yunnan UniversityKunming 650091China Département de Physique Nucléaire et Corpusculaire Facultéde SciencesUniversitéde Genève24 Quai Ernest Ansermet1211 GenevaSwitzerland Institute of Frontier and Interdisciplinary Science Shandong UniversityQingdao 266237China APC Universit'e Paris Cit'eCNRS/IN2P3CEA/IRFUObservat

The full array of the Large High Altitude Air Shower Observatory(LHAASO)has been in operation since july *** its kilometer-square array(Km2A),we optimized the selection criteria for very high and ultrahigh energyγ-rays using data collected from August 2021 to August 2022,resulting in an improvement in significance of the detection in the Crab Nebula of approximately 15%,compared with that of previous *** the implementation of these new selection criteria,the angular resolution was also significantly improved by approximately 10%at tens of *** aspects of the full Km2A array performance,such as the pointing error,were also calibrated using the Crab *** resulting energy spectrum of the Crab Nebula in the energy range of 10-1000 TeV are well fitted by a log-parabola model,which is consistent with the previous results from LHAASO and other experiments.

关键词： γ-ray Crab Nebula significance

Spectral hole burning effects initiated by uniform signal intensities in a gain-flattened EDFA

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Chinese Optics Letters 2011年第2期9卷 11-14页

作者： A.r.Sarmani S-j Sheih F.r.mahamd Adikan m.A.mahdi Wireless and Photonics Networks research Center Faculty of Engineering Universiti Putra Malaysia Taiwan International Securities Group Department of Electrical Engineering Faculty of Engineering Universitiy of Malaya

Spectral hole burning （SHB） effects in a gain-flattened erbium-doped fiber amplifier （EDFA） are demonstrated to be significant in the presence of large signal power around the 1530-1532-nm wavelength range. These are the first effects reported in a setup employing equivalent power level distribution of 40 channels ranging from 1530 to 1561 nm. To explain this, the introduction of a new local population variable into the laser equation is required to support the original inversion ratio that is determined by the pump lasers. In the analysis section, spectroscopic parameters and high signal powers are considered to be other contributing parameters to the change in the gain characteristics. An improvement to this theoretical basis is suggested by implementing mathematical modeling to validate similarities between the gain shape of simulation to that obtained in the experiment.

关键词： Erbium Fiber amplifiers Pumping (laser) Spectroscopic analysis

Auxin signaling gets oxidative to promote root hair growth

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molecular Plant 2024年第5期17卷 696-698页

作者： Victoria Berdion Gabarain miguel A.Ibeas Hernan Salinas-Grenet jose m.Estevez Fundación Instituto Leloir&IIBBA-CONICET Av.Patricias Argentinas 435Buenos Aires C1405BWEArgentina Centro de Biotecnología Vegetal Facultad de Ciencias de la VidaUniversidad Andres BelloSantiagoChile ANID Millennium Science Initiative ProgramMillennium Nucleus for the Development of Super Adaptable Plants(MN-SAP)SantiagoChile ANID Millennium Science Initiative ProgramMillennium Institute for Integrative Biology(iBio)SantiagoChile

root hairs(rHs)emerge as cylindrical cell protrusions from the root epidermis in a polar manner,and these outgrows increase the rhizosphere space to acquire water and nutrients,anchor the plant,and interact with various soil *** is one of the key hormones to promote rH growth,and high levels of auxin are directly promoted by low levels of macronutrients in the soil,such as phosphate(Bhosale et al.,2018)and nitrates(jia et al.,2023).The nutritional signals for roots,which rapidly change in both time and place within the soil,are tightly linked to signaling pathways that execute swifts on cellular processes to adjust to a challenging *** rapid alkalinization factors(rALFs)are peptides that are released outside the cell and act as peptide-hormone *** attach to the extracellular domains of members of the Catharanthus roseus rECEPTOr-LIKE KINASE 1-LIKE family,specifically FErONIA(FEr)in conjunction with its co-receptor LOrELEI-LIKE-GPIANCHOrED PrOTEIN 1.

关键词： soil outside alkali

Effect of La on the Corrosion Behavior and mechanism of 3Ni Weathering Steel in a Simulated marine Atmospheric Environment

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Acta metallurgica Sinica(English Letters) 2024年第2期37卷 308-324页

作者： Gang Niu rui Yuan r.D.K.misra Na Gong Zhi-Hui Zhang Hao-Xiu Chen Hui-Bin Wu Cheng-jia Shang Xin-Ping mao Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing100083China Laboratory for Excellence in Advanced Steel research Department of MetallurgicalMaterials and Biomedical EngineeringUniversity of Texas at El PasoEl PasoTX79968USA Institute of materials research and Engineering Agency for ScienceTechnologyand ResearchSingapore138634Singapore Department of materials Science and Engineering University of TorontoTorontoONM5S 3E4Canada

The corrosion behavior and mechanism of 3Ni weathering steel in a simulated oceanic atmospheric environment are investigated in order to comprehend the impacts of La,as determined through electrochemical analysis and rust layer *** results of this study demonstrate that the addition of La enhances the corrosion resistance of 3Ni weathering steel in the marine atmospheric environment,thereby reducing the corrosion rate and improving the protection of the rust *** influence of La on corrosion resistance can be attributed to two primary ***,La functions as a grain refiner,minimizing the potential difference of the micro-regions on the substrate surface,thereby significantly reducing the corrosion of bare steel in the marine ***,La inhibits the process of Fe_(3)O_(4) oxidation back toγ-FeOOH during corrosion at the local site,thus decreasing the formation ofγ-FeOOH and enhancing the charge transfer *** research work may serve as a reference for expanding the application of rare earth elements in the field of weathering steel.

关键词： Weathering steel rare earth rust layer Corrosion behavior Corrosion resistance