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Particle Image Velocimetry Study of Turbulence Characteristics in a Vessel Agitated by a Dual Rushton Impeller

Chinese Journal of Chemical Engineering 2008年第5期16卷 700-708页

作者：刘心洪包雨云李志鹏高正明 John m. smith School of Chemical Engineering Beijing University of Chemical Technology Beijing 100029 China Fluids and Systems Research Centre School of Engineering （J2） University of Surrey Guildford GU2 7XH UK

Particle Image Velocimetry （PIV） has been used to investigate turbulence characteristics in a 0.48 m diameter stirred vessel filled to a liquid height （ H = 1.4T ） of 0.67 m. The agitator had dual Rushton impellers of 0.19 m diameter （ D = 0.4T ）. The developed flow patterns depend on the clearance of the lower impeller above the base of the vessel, the spacing between the two impellers, and the submergence of the upper impeller below the liq- uid surface. Their combinations can generate three basic flow patterns, named, parallel, merging and diverging flows. The results of velocity measurement show that the flow characteristics in the impeller jet flow region changes very little for different positions. Average velocity, trailing vortices and shear strain rate distributions for three flow patterns were measured by using PIV technique. The characteristics of trailing vortex and its trajectory were described in detail for those three flow patterns. Since the space-resolution of PIV can only reach the sub-grid rather than the Kolmogorov scale, a large-eddy PIV analysis has been used to estimate the distribution of the turbulent kinetic energy dissipation. Comparison of the distributions of turbulent kinetic energy and dissipation rate in merging flow shows that the highest turbulent kinetic energy and dissipation are both located in the vortex regions, but the maxima are at somewhat different lo- cations behind the blade. About 37% of the total energy is dissipated in dual impeller jet flow regions. The obtained distribution of shear strain rate for merging flow is similar to that of turbulence dissipation, with the shear strain rate around the trailing vortices much higher than in other areas.

关键词： dual Rushton impeller flow pattern large-eddy particle image velocimetry trailing vortex kinetic energy dissipation rate

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Regeneration of adhesive tail pad scales in the New Zealand gecko (Hoplodactylus maculatus) (Reptilia, Squamata; Lacertilia) can serve as an experimental model to analyze setal formation in lizards generally

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Zoological Research 2017年第4期38卷 191-197页

作者： lorenzo Alibardi Benno meyer-Rochow Comparative Histolab and Department of Bigea Dipartimento di Biologia University of Bologna Bologna 40126 Italy Research Institute of Luminous Organisms Tokyo 100-1623 Japan Department of Genetics and Physiology Oulu University Oulu FIN 90140 Finland

During the regeneration of the tail in the arboreal New Zealand gecko （Hoplodactylus maculatus） a new set of tail scales, modified into pads bearing setae 5-20 μm long, is also regenerated. Stages of the formation of these specialized scales from epidermal pegs that invaginate the dermis of the regenerating tail are described on the basis of light and electron microscopic images. Within the pegs a differentiating clear layer interfaces with the spinulae and setae of the Oberh^utchen according to a process similar to that described for the digital pads. A layer of clear cytoplasm surrounds the growing tiny setae and eventually comities around them and their spatular ends, later leaving the new setae free- standing on the epidermal surface. The fresh adhesive pads help the gecko to maintain the prehensile function of its regenerated tail as together with the axial skeleton （made of a cylinder of elastic cartilage） the pads allow the regenerated tail to curl around twigs and small branches just like the original tail. The regeneration of caudal adhesive pads represents an ideal system to study the cellular processes that determine setal formation under normal or experimental manipulation as the progressive phases of the formation of the setae can be sequentially analyzed.

关键词： Gecko lizard Regeneration Epidermis Tail pad scales Adhesion Prehensile function Ultrastructure

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What we have learned from randomized trials of prostate cancer screening

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Asian Journal of Andrology 2011年第3期13卷 369-373,510页

作者： Richard m Hoffman Anthony Y smith medicine Service New Mexico VA Health Care System Albuquerque NM 87108 USA Department of medicine University of New Mexico School of Medicine Albuquerque NM 87108 USA Department of Surgery University of New Mexico School of Medicine Albuquerque NM 87108 USA

The introduction of prostate-specific antigen （PSA） for prostate cancer screening in the late 1980s led to an epidemic of prostate cancer, particularly in developed countries. However, the first valid reports from randomized controlled trials on the efficacy of screening were not published until 2009. men in the screening group in the European Randomized Study of Screening for Prostate Cancer were 20% less likely than those in the control group to die from prostate cancer. The absolute difference was only 0.7/1000, implying that over 1400 men needed to be screened to prevent one prostate cancer death. Screening was also associated with a 70% increased risk for being diagnosed with prostate cancer. The American Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial found no survival benefit for screening. Results were not conclusive because a substantial proportion of study subjects had previously undergone PSA testing, over half of the control group had PSA testing, follow-up was relatively short, and fewer than 100 subjects died from prostate cancer. Balancing the potential survival benefit from screening is the risk of overdiagnosis--finding cancers that would not otherwise cause clinical problems^and the risk of treatment complications, including urinary, sexual and bowel dysfunction. Prostate cancer screening efforts would benefit from improved biomarkers, which more readily identify clinically important cancers. Cancer control efforts might also need to include chemoprevention, though currently available agents are controversial. In the meantime, oatients need to be supoorted in achievine informed decisions on whether to be screened for orostate cancer.

关键词： cancer screening prostate-specific antigen prostatic neoplasms randomized controlled trials as topic

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A Hybrid model Evaluation Based on PCA Regression Schemes Applied to Seasonal Precipitation Forecast

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Atmospheric and Climate Sciences（大气和气候科学） 2024年第3期 328页

作者： Pedro m.González-Jardines Aleida Rosquete-Estévez maibys Sierra-lorenzo Arnoldo Bezanilla-morlot

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建立数字式行点阵记录仪标准特性的必要性

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遥测遥控 1989年第6期10卷 55-60页

作者： Grant m.smith Dave Gaskill 张伟

各地的遥测数据接收处理站都在用数字式行点阵记录仪来取代传统的笔式记录仪。前者具有多方面的优越性,并在实际应用中日益成为必不可少的设备。但由于工作原理和记录方式完全不同,人们很难将这两类记录仪的性能进行全面的类比,因此,在... 详细信息

各地的遥测数据接收处理站都在用数字式行点阵记录仪来取代传统的笔式记录仪。前者具有多方面的优越性,并在实际应用中日益成为必不可少的设备。但由于工作原理和记录方式完全不同,人们很难将这两类记录仪的性能进行全面的类比,因此,在打算淘汰已经使用日久的笔式记录仪就使人举棋不定。目的:为数字式记录仪建立一套通用的标准特性;介绍有关的术语,以便对新旧系统进行正确的并且是可重复的比较。

关键词：数字式记录仪遥测记录特性

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ζ-Carotene Isomerase Suppresses Tillering in Rice through the Coordinated Biosynthesis of Strigolactone and Abscisic Acid

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molecular Plant 2020年第12期13卷 1784-1801页

作者： Xue Liu Qingliang Hu Jijun Yan Kai Sun Yan Liang meiru Jia Xiangbing meng Shuang Fang Yiqin Wang Yanhui Jing Guifu Liu Dianxing Wu Chengcai Chu Steven m.smith Jinfang Chu Yonghong Wang Jiayang Li Bing Wang State Key Laboratory of Plant Genomics and National Center for Plant Gene Research(Beijing)Institute of Genetics and Developmental BiologyInnovation Academy for Seed DesignChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Rice Biology Institute of Nuclear Agriculture SciencesZhejiang UniversityHangzhou 310029China School of Natural Sciences University of TasmaniaHobart 7001Australia State Key Laboratory of Plant Genomics and National Center for Plant Gene Research(Beijing)Institute of Genetics and Developmental BiologyThe CAS Center for Excellence in Molecular Plant SciencesChinese Academy of SciencesBeijing 100101China College of Life Sciences Shandong Agricultural UniversityTaian 271018China

Rice tillering is an important agronomic trait affecting grain ***,we identified a high-tillering mutant tillering20(t20),which could be restored to the wild type by treatment with the strigolactone(SL)analog rac-GR24.T20 encodes a chloroplast ζ-carotene isomerase(Z-ISO),which is involved in the biosynthesis of ca-rotenoids and their metabolites,SL and abscisic acid(ABA).The t20 mutant has reduced SL and ABA,raising the question of how SL and ABA biosynthesis is coordinated,and whether they have overlapping functions in *** discovered that rac-GR24 stimulated T20 expression and enhanced all-trans-p-carotene ***,rac-GR24 also stimulated expression of Oryza sativa 9-CIS-EPOXY-CAROTENOID DIOXYGENASE 1(OsNCED1)through induction of Oryza sativa HOmEOBOX12(0sHOX12),promoting ABA biosynthesis in shoot *** the other hand,ABA treatment significantly repressed SL biosynthesis and the ABA biosynthetic mutants displayed elevated SL *** treatment reduced the number of basal tillers in both t20 and wild-type ***,while ABA-deficient mu-tants aba1 and aba2 had the same number of basal tillers as wild type,they had more unproductive upper tillers at *** work demonstrates complex interactions in the biosynthesis of carotenoid,SLs and ABA,and reveals a role for ABA in the regulation of rice tillering.

关键词： rice(Oryza sativa L.) tillering ζ-carotene isomerase carotenoid strigolactones abscisic acid

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Hydrophobicity of Highly Ordered Nanorod Polycrystalline Nickel and Silver Surfaces

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Journal of minerals and materials Characterization and Engineering 2019年第5期7卷 279-293页

作者： Jan macko Natalia Podrojkova Radim Hrdy Andrej Orinak Renata Orinakova Jaromir Hubalek Jaroslav Vojtus Zuzana Kostecka Roger m.smith Department of Physical Chemistry University of P.J.Safarik in KosiceKosiceSlovakia Depatrment of microelectronics Brno University of TechnologyBrnoCzech Republic Central European Institute of Technology Brno University of TechnologyBrnoCzech Republic Department of Architectural Engineering Institute of Architectural EngineeringKosiceSlovakia University of Veterinary medicine and Pharmacy KosiceSlovakia Department of Chemistry Loughborough UniversityLoughboroughUK

Highly ordered nickel and silver nanorods arrays prepared by alumina template assisted electrodeposition were investigated to determine the effect of the array geometry on metal surface hydrophobicity and adhesion forces. The nanorod geometry, clustering and pinning were used to characterize surface hydrophobicity and its modulation. A contribution of metal crystallographic orientation to the surface energy was calculated. To characterize nanorod array surface properties and elucidate the source of the particle adhesion effects has been calculated. The dispersive components of surface tension?γSD?and surface polarizability ks, as surface features that markedly characterize hydrophobicity and adhesion, were calculated. The highest hydrophobicity was found for Ag nanorods with aspect ratio of 10 then Ni nanorods with aspect ratio 10. The same geometry of nanorods particles resulted in different surface hydrophobicity and it was ascribed to the orientation of Ag and Ni crystals formed on the top of nanorods. Due to high hydrophobicity nanorod array surfaces could be used as an antifouling surface in medicine to select areas on implant surface not to be colonized by cells and tissues.

关键词： Nanorods Silver Nickel Hydrophobicity Surface Energy Crystallinity

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Ultrastructure of Bat (Pipistrellus kuhlii) Epidermis with Emphasis on Terminal Differentiation of Corneocytes

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Zoological Research 2006年第1期27卷 86-93页

作者： lorenzo ALIBARDI 意大利博洛尼亚大学生物进化实验系

The ultrastrncture of the skin of air-adapted mammals （bats） is not known. The study at the electron microscope of the skin of the back and the flying membrane of Pipistrellus kuhlii showed that the thickness of the epidermis is very low （10- 12μm）, and that 1 - 2 flat spinosus cells are present beneath the stratum corneum which is formed by very thin corneoeytes that resemble those of avian apteric epidermis. The stratum granulosum is discontinuous and few small （less than 0.3μm large） keratohyalin granules are present. The epidermis is reduced to one flat basal layer in contact with the stratum corneum in many areas of the flying membrane. Transitional corneoeytes are almost absent suggesting that the process of eornification is very rapid. In the basement membrane numerous hemidesmosomes are present and form attachment points for the dense dermis underneath. Numerous collagen fibrils directly contact with the hemidesmosomes and the dense lamella of the basement membrane. Sparse elastic fibrils allow the stretching of the epidermis during flight and the rapid folding of the epidermis after flying without damaging the epidermis. Like in avian epidermis, the production of lipids is high in bat keratinocytes, and multilamellar bodies discharge lipids extra- and intra-cellularly. This may compensate the lack of a thick fat layer in the dermis of the flying membrane as lipids may help in thermical insulation against the cooling air currents flowing on the bat skin during flight. Fur hairs are very thin （4 - 7 μm）, and they have an elaborated cuticle made of pointed expansions similar in texture with that of the cortex. Cuticle ceils form hook-like grasping points that allow to keep hairs stuck together. In this way the pelage remains compact in order to maintain body temperature.

关键词： Bat Skin Epidermis Hairs Comification Ultrastructure

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海洋磁异常的磁源层—DSDP 第83航次的部分成果

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海洋石油 1986年第1期 59-61页

作者： Guy m.smith 李培廉

深海钴探计划第83航次是钻入未受扰动的洋壳最深的一次钻探,这次钻探提供了喷发岩层下部和席状岩墙杂岩上部300米的岩样。本文介绍了采自83航次的岩石的磁性,并提出它们适于作为海洋磁异常磁源层的问题。我们发现,由于广泛的热液蚀变作... 详细信息

深海钴探计划第83航次是钻入未受扰动的洋壳最深的一次钻探,这次钻探提供了喷发岩层下部和席状岩墙杂岩上部300米的岩样。本文介绍了采自83航次的岩石的磁性,并提出它们适于作为海洋磁异常磁源层的问题。我们发现,由于广泛的热液蚀变作用,83航次剖面的喷发岩局部被不充分地磁化而成为属源层。另一方面,席状岩墙杂岩则已充分磁化,与当前基于蛇绿岩研究确立的海洋磁化模式相反,席状岩墙杂岩可以是海洋磁异常的磁源层。磁性对岩石蚀变史的密切依从关系,使得这些成果可扩大到其它未知区。

关键词：席状岩墙杂岩岩层磁性岩石磁异常 DSDP 蛇绿岩超基性岩磁源

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Circularly polarized luminescence of enantiopure carboline-based europium cryptates under visible light excitation

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Journal of Rare Earths 2020年第5期38卷 564-570页

作者： Carolin Dee Francesco Zinna Elisabeth Kreidt lorenzo Arrico Aurora Rodriguez-Rodriguez Carlos Platas-Iglesias lorenzo Di Bari michael Seitz University of Tübingen Institute of Inorganic ChemistryAuf der Morgenstelle 1872076TubingenGermany Dipartimento di Chimica e Chimica Industriale Universita di PisaVia Moruzzi 1356124PisaItaly Centro de Investigacions Cientificas Avanzadas(CICA)and Departamento de Quimica Universidade da CorunaCampus da Zapateira-Rua da Fraga 1015008A CorunaSpain

The enantiomers of carboline-based cryptates were successfully resolved by chiral *** complexes show high configurational stability under harsh conditions and their absolute configuration was determined by comparing theoretical and expe rimental electronic circular dichroism *** e nantiopure cryptates exhibit strong circularly polarized luminescence with a maximum dissymmetry factor glum=0.25 for the f-f transition 5 D0→7 F1(λ=594 nm)under visible light excitation atλgx=400 nm.

关键词： molecular lanthanoid complexes Lanthanoid luminescence Chirality Circularly polarized luminescence(CPL) Carboline Cryptates

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