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Advances in Atmospheric Sciences 2011年第1期28卷 187-194页

作者：李倩 hans-F.GRAF 崔雪锋 Key Laboratory of Middle Atmosphere and Global environment Observation Institute of Atmospheric PhysicsChinese Academy of Sciences School of GeoSciences University of Edinburgh Center for Atmospheric Science University of Cambridge State Key Laboratory of earth Surface Processes and Resource ecology College of Global Change and Earth System ScienceBeijing Normal University

Using 1958-2002 NCePNCAR reanalysis data, we investigate stationary and transient planetary wave propagation and its role in wave-mean flow interaction which influences the state of the polar vortex （PV） in the stratosphere in Northern Hemisphere （NH） winter. This is done by analyzing the eliassen-Palm （e-P） flux and its divergence. We find that the stationary and transient waves propagate upward and equatorward in NH winter, with stronger upward propagation of stationary waves from the troposphere to the stratosphere, and stronger equatorward propagation of transient waves from mid-latitudes to the subtropics in the troposphere. Stationary waves exhibit more upward propagation in the polar stratosphere during the weak polar vortex regime （WVR） than during the strong polar vortex regime （SVR）. On the other hand, transient waves have more upward propagation during SVR than during WVR in the subpolar stratosphere, with a domain of low frequency waves. With different paths of upward propagation, both stationary and transient waves contribute to the maintenance of the observed stratospheric PV regimes in NH winter.

关键词： stratospheric polar vortex planetary waves stationary transient

Pacing and predictors of performance during cross-country skiing races:A systematic review

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Journal of Sport and Health Science 2018年第4期7卷 381-393页

作者： thomas stoggl barbara pellegrini hans-christer holmberg department of sport and exercise science university of salzburgHallein/Rif 5400Austria cerism research centre"sport mountainand health"Rovereto 36068Italy department of neuroscience biomedicine and movementuniversity of veronaVerona 37100Italy swedish winter sports research centre mid sweden universityOstersund 83128 Sweden school of sport sciences uit arctic university of norwayTromso 9037 Norway school of kinesiology university of british columbiaVancouverBC V6T 121Canada department of physiology and pharmacology karolinska institutetStockholm 17177Sweden

Background: Cross-country skiing(XCS) racing, a popular international winter sport, is complex and challenging from physical, technical, and tactical perspectives. Despite the vast amount of research focusing on this sport, no review has yet addressed the pacing strategies of elite XCS racers or the factors that influence their performance. The aim was to review the scientific literature in an attempt to determine the effects of pacing strategy on the performance of elite XCS ***: Four electronic databases were searched using relevant subject headings and keywords. Only original research articles published in peerreviewed journals and the english language and addressing performance, biomechanics, physiology, and anthropometry of XCS racers were ***: All 27 included articles applied correlative designs to study the effectiveness of different pacing strategies. None of the articles involved the use of an experimental design. Furthermore, potential changes in external conditions(e.g., weather, ski properties) were not taken into consideration. A comparable number of studies focused on the skating or classical technique. In most cases, positive pacing was observed, with certain indications that higher-level athletes and those with more endurance and strength utilized a more even pacing strategy. The ability to achieve and maintain a long cycle length on all types of terrain was an important determinant of performance in all of the included studies, which was not the case for cycle rate. In general, uphill performance was closely related to overall race performance, with uphill performance being most closely correlated to the success of female skiers and performance on flat terrain being more important for male skiers. Moreover, pacing was coupled to the selection and distribution of technique during a race, with faster skiers employing more double poling and kick double poling,less diagonal stride, and more V2(double dance) than V1(single dance)

关键词：滑雪性能赛跑评论系统预言冬季运动周期长度

The pairwise velocity difference of over 2000 BHB stars in the Milky Way halo

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Research in Astronomy and Astrophysics 2009年第11期9卷 1230-1240页

作者： Xiang-Xiang Xue hans-Walter Rix Gang Zhao National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China Max-Planck-Institute for Astronomy Konigstuhl 17 D-69117 Heidelberg Germany Graduate University of Chinese Academy of Sciences Beijing 100049 China

Models of hierarchical galaxy formation predict that the extended stellar halos of galaxies like our Milky Way show a great deal of sub-structure, arising from disrupted satellites. Spatial sub-structure is directly observed, and has been quantified, in the Milky Way＇s stellar halo. Phase-space conservation implies that there should be sub-structure in position-velocity space. Here, we aim to quantify such position-velocity sub-structure, using a state-of-the art data set having over 2000 blue horizontal branch （BHB） stars with photometry and spectroscopy from SDSS. For stars in dynamically cold streams （＂young＂ streams）, we expect that pairs of objects that are physically close also have similar velocities. Therefore, we apply the well-established ＂pairwise velocity difference＂（PVD） statistic （｜ △Vlos ｜）（△r）, where we expect （｜ △Vlos ｜） to drop for small separations At. We calculate the PVD for the SDSS BHB sample and find 〈｜ △Vlos ｜〉（△r） ≈ const., i.e. no such signal. By making mock-observations of the simulations by Bullock ＆ Johnston and applying the same statistic, we show that for individual, dynamically young streams, or assemblages of such streams, （｜ △Vlos ｜） drops for small distance separations At, as qualitatively expected. However, for a realistic complete set of halo streams, the pair-wise velocity difference shows no signal, as the simulated halos are dominated by ＂dynamically old＂ phase-mixed streams. Our findings imply that the sparse sampling and the sample sizes in SDSS DR6 are still insufficient to use the position-velocity sub-structure for a stringent quantitative data-model comparison. Therefore, alternate statistics must be explored and much more densely sampled surveys, dedicated to the structure of the Milky Way, such as LAMOST, are needed.

关键词： cosmology dark matter-- galaxies individual (Milky Way) -- galaxy halo -- stars horizontal-branch- stars kinematics

Heat Transfer and Hydrodynamics in Annular Chromatography: CFD-Simulation and experiments

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Journal of Thermal Science 2000年第2期9卷 129-134页

作者： hans－JoergBart JorgBrozio 等 UniversitaetKaisersautern LehrstuhifuerThermischeVerfachrenstechnikPostfach3049D－67653KaiserslauternGermanyE－amil：bart@mv.uni－kl.de UniversitaetKaisersautern LehrstuhifuerThermischeVerfachrenstech

Continuous annular chromatography(CAC) is a separation process for multicomponent liquid mixtures. The performance of the apparatus can be seriously decreased by temperature gradients inside the adsorbent bed. It is shown, that the temperature gradients can be significantly reduced by a pre-heating of the entering liquid in the apparatus itself. Heat transfer and hydrodynamics in the porous media are described by two different modelling approaches. Both are based on a pseudo-homogeneous model for heat transfer with temperature dependent fluid viscosities. The first model considers one-dimensional fluid now and two-dimensional heat transfer. The second, more rigorous one is a three-dimensional model for heat transfer and hydrodynamics. The simulation results obtained with both models are in good agreement with experimental results. The experiments have been performed with glass beads as the stationary phase and water as the liquid phase under different boundary conditions. The temparature profiles inside the packed bed have been measured with thermocouples.

关键词：热传输流体力学模拟实验

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恶性间皮瘤29例分析

中国肿瘤临床 1991年第4期18卷 227-229页

作者：周晓南 hans.,e Department of Respiratory Disease Ningxia Medical College Ningxia China

本文回顾加拿大金斯顿总医院从1950～1987年经组织活检或尸检证实的恶性间皮瘤死亡病例29人,发现该病逐年增长,男与女之比为3:1,胸膜间皮瘤与腹膜间皮瘤之比亦为3:1,近半数患者年龄为50～59岁。胸膜间皮瘤的初始症状为气短、胸痛、咳嗽... 详细信息

本文回顾加拿大金斯顿总医院从1950～1987年经组织活检或尸检证实的恶性间皮瘤死亡病例29人,发现该病逐年增长,男与女之比为3:1,胸膜间皮瘤与腹膜间皮瘤之比亦为3:1,近半数患者年龄为50～59岁。胸膜间皮瘤的初始症状为气短、胸痛、咳嗽和体重减轻,胸片表现为胸腔积液、块影和胸膜增厚,原发灶约2/3在右侧。腹膜间皮瘤主要表现为腹块、腹痛及腹水,预后较胸膜间皮瘤更差。手术组预后略好,其他各治疗组与未治组的存活时间无显著性差异。分析各组患者确诊时的一般状况、接受治疗者所承担的风险、痛苦及花费,建议今后对已确诊的恶性间皮瘤病人,特别是Ⅱ期以上患者,在未有更有效疗法前,均可停止治疗,任其安乐死亡。

关键词：恶性间皮瘤胸膜腹膜预后

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丑小鸭

Solubility Product of Ni-Struvite, NH4NiPO4·6H2O, at 25°C

丛书名： WOW！不可思议的漫画英语

2011年

作者： (丹)安徒生(hans Christian andersen)原

本书选取了小朋友们最喜爱的故事丑小鸭，寓教于乐，让小朋友们在阅读故事的乐趣中学习英语。

ISBN: (纸本)7564041609

本书选取了小朋友们最喜爱的故事丑小鸭，寓教于乐，让小朋友们在阅读故事的乐趣中学习英语。

关键词：漫画

来源：畅想之星图书光盘版（南... 评论

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Advances in Chemical engineering and Science 2017年第2期7卷 206-214页

作者： hans e. Lundager Madsen Chemistry Department University of Copenhagen Copenhagen Denmark

Solubility product of a sparingly soluble salt is an important parameter in both pure and applied physical chemistry such as determination of values of thermodynamic functions or environmental implications of components of the substance. This paper presents the determination of the solubility product of ammonium nickel phosphate hexahydrate (Ni-struvite) at 25°C by analysis of equilibria attained from both supersaturated and undersaturated solutions, i.e. precipitation and dissolution, respectively. Writing the dissolution process as NH4NiPO4·6H2O → NH3 + Ni2+ ++ 6 H2O, the value pKsp = 11.03 ± 0.03 is found for both precipitation and dissolution. The solubility is a little lower than that of the isomorphous Mg salt. This is to be expected from the lattice dimensions of the two phases, the crystals of Ni-struvite being slightly more compact.

关键词： Ammonium Nickel Phosphate Ni-Struvite Solubility Product

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卖火柴的小女孩(英文)