Vortex Rossby Waves in Asymmetric Basic Flow of Typhoons

Wave ray theory is employed to study features of propagation pathways（rays） of vortex Rossby waves in typhoons with asymmetric basic flow, where the tangential asymmetric basic flow is constructed by superimposing the wavenumber-1 perturbation flow on the symmetric basic flow, and the radial basic flow is derived from the non-divergence equation. Results show that, in a certain distance, the influences of the asymmetry in the basic flow on group velocities and slopes of rays of vortex Rossby waves are mainly concentrated near the radius of maximum wind（RMW）, whereas it decreases outside the RMW. The distributions of radial and tangential group velocities of the vortex Rossby waves in the asymmetric basic flow are closely related to the azimuth location of the maximum speed of the asymmetric basic flow, and the importance of radial and tangential basic flow on the group velocities would change with radius. In addition, the stronger asymmetry in the basic flow always corresponds to faster outward energy propagation of vortex Rossby waves. In short, the group velocities, and thereby the wave energy propagation and vortex Rossby wave ray slope in typhoons, would be changed by the asymmetry of the basic flow.

NONLINEAR SATURATION OF BAROCLINIC INSTABILITY IN THE GENERALIZED PHILLIPS MODEL(Ⅱ)- THE LOWER BOUND ON THE DISTURBANCE ENERGY AND POTENTIAL ENSTROPHY TO THE NONLINEARLY UNSTABLE BASIC FLOW

On the basis of the nonlinear stability theorem in the context of Arnol'd's second theorem for the generalized Phillips model,nonlinear saturation of baroclinic instability in the generalized Phillips model is investigatedThe lower bound on the disturbance energy and potential enstrophy to the nonlinearly unstable basic flow in the generalized Phillips model is presented,which indicates that there may exist an allocation between a nonlinearly unstable basic flow and a growing disturbance

Relationship between the Interannual Variations of Total Ozone in the Northern Hemisphere and the QBO of Basic Flow in the Tropical Stratosphere

The harmonic analyses of monthly mean total ozone in the atmosphere over the Northern Hemisphere for 26 years (1960-1985) are made by using the Fourier expansion. The analysed results show that there is obviously a quasi-biennial oscillation (QBO) in the interannual variations of the amplitudes of total ozone. Generally, the amplitudes of wavenumber 1 and 2 during the westerly of the equatorial QBO are larger than those during the easterly. In the early winter, the amplitude of wavenumber 1 during the easterly phase is larger, and in the late winter, it is larger during the westerly phase. These are in good agreement with the observational distributions.

Strongly nonlinear long interfacial waves in uniform basic flows and their dispersion relationship

In this paper, long interfacial waves of finite amplitude in uniform basic flows are considered with the assumption that the aspect ratio between wavelength and water depth is small. A new model is derived using the velocities at arbitrary distances from the still water level as the velocity variables instead of the commonly used depth-averaged velocities. This significantly improves the dispersion properties and makes them applicable to a wider range of water depths. Since its derivation requires no assumption on wave amplitude, the model thus can be used to describe waves with arbitrary amplitude.

INFLUENCE OF THE BASIC FLOW IN THE TROPICS ON THE STATIONARY PLANETARY WAVES AT MIDDLE AND HIGH LATITUDES DURING THE NORTHERN HEMISPHERE WINTER

The relationship between the quasi-stationary planetary waves forced by topography and heat source during the Northern Hemisphere winter is investigated by means of a quasi-geostrophic,34-level,spherical coordinate model with the Rayleigh friction,the Newtonian cooling and the horizontal eddy thermal diffu- sion. The calculated results show that when the basic flow is the westerly in the tropical stratosphere,the amplitude of quasi-stationary planetary wave for zonal wavenumber 2 at middle and high latitudes is larger during the Northern Hemispheric winter;while when the basic flow is the easterly,it is smaller.This is in agreement with the observed results. The calculated results also show that influence of the basic flow in the tropical troposphere on the quasi- stationary planetary waves is larger than that of the basic flow in the tropical stratosphere on the quasi- stationary planetary waves.

Symmetric Development of Meso Perturbation in Zonally Curved Basic Flow

Addressed is a problem as to meso perturbation wave ensemble development in a curved basic flow in the context of a f-plane non-hydrostatic equilibrium acoustic wave filtering model in natural coordinates with the aid of the WKJB and energetic approaches. Results show that the symmetric development depends crucially on the matching of structures of the disturbance wave and background field, and for a smooth (curved) basic flow the wave ensemble evolution hinges upon the spatial imhomogeneity of nonthermal wind of the background field (under nongradient wind balance). Finally, presented is the wave ensemble evolution in relation to the thermal curvature vorticity in the background field.

EFFECT OF LOCAL BASIC FLOW STRUCTURE PATTERN IN FORMATION OF BLOCKING HIGHS

The effect of local basic flow structure pattern(BFSP)on a blocking high formation is investigated within the framework of forced dissipation KDV dynamics.The zonal and meridional positions of the high's center excited by a heat source depend on the BFSP selected.

Influences of basic flow on unstable excitation of intraseasonal oscillation in mid-high latitudes

The influences of basic flow fields on the unstable excitation of the intraseasonal atmosphericoscillation in the mid-high latitudes are studied by using a simple nonlinear dynamical model.The results showthat the westerly profile has an important effect on unstable modes in the atmosphere;the growth rates andspectrum distributions of the excited unstable modes are different for the different profiles.For the usualwesterly profile patterns in the real atmosphere,the most unstable mode is in the intraseasonal(30—60 d)frequency band.The local intensity and meridional gradient of the westerlies also clearly affect unstablemodes.The consistency of the results in observational data analyses with that in dynamical theory proved thecorrectness and rationalization of the above-mentioned results.

CALCULATION OF BASIC ENVIRONMENTAL GEOSTROPHIC FLOW AND STATISTICAL STUDY ON TC TRACK AND ITS DEVIATION

Using the T63L16 analysis data with the resolution of 1.875╳1.875 degree of latitude and lon-gitude obtained from National Meteorological Center (NMC) and the real central position information of tropi-cal cyclone (referred to as TC hereafter) numbered by NMC, the basic environmental geostrophic flow at 126 time levels of 25 TCs in 1996 are calculated. The vertical distribution features of the flows are analyzed. Be-sides, the deviation of real TC tracks from the flows (referred as steering deviation hereafter, namely, the de-viation between the real central position of TC and the position calculated according to the steering flow) is also investigated. The result shows that the steering deviation would be different if the domain used to calculate the steering flow is different. The present paper obtains the optimum domain size to calculate the steering flow. It is found that the steering deviation is related to the velocity of steering flow and the initial latitude and intensity of TC itself, and that TC motion has relationship with the vertical shear structure of environmental geostrophic flow. The result also shows that the optimum steering flow is the deep-layer averaged basic flow from 1000 hPa to 200 hPa. Having the knowledge of these principle and features would help make accurate forecast of TC motion.

新时代高校教育、科技、人才一体化布局与科学基金发展策略

在世界新一轮科技产业革命加速演进的背景下,教育、科技、人才“三位一体”统筹布局成为我国全面建设社会主义现代化国家的基础性和战略性支撑。高校是科技强国、人才强国、教育强国三大战略的交汇点,科学基金作为促进创新链—产业链—资金链—人才链—学科链深度融合的重要渠道和枢纽,在一体布局下面临新的要求和挑战。文章围绕如何“有力统筹教育、科技、人才工作”的关键问题,明确新时代高校在教育、科技、人才一体布局的定位、内涵和要求,挖掘教育优先、科技自强、人才引领的现实困境与发展前景,以期为科学基金发展提出有针对性的方案和建议。

高校人才流动与基础研究创新产出

激发创新主体活力,是知识经济时代提升国家创新体系整体效能和建设世界科技强国的重要内容。学术人才流动作为高校间人才竞争的表现形式,能否带来基础研究创新产出的提升以及相应的作用机制尚待明确。基于Web of Science数据库2008—2018年中国高校发表的论文数据,使用固定效应模型和工具变量方法从学术人才流动的视角回答如何提升基础研究科研效率这一问题。研究发现,高校人才流动能够促进知识溢出,从而提升高校基础研究产出效率。机制分析表明,高校之间的人才流动通过研究人员合作论文数量的增加以及流入学者与高校之间更好的匹配来实现高校科研效率的提升。异质性分析表明,高校人才流入对基础研究创新产出的影响在社会科学领域以及人才流向东部高校中更为显著。研究结论为现阶段如何提升基础研究产出效率、释放学术人才红利提供参考。

基本路径测试技术及应用研究

基本路径测试法是一种白盒测试方法,文章将程序流程图映射成流图,探讨了程序的3种基本结构映射成流图的方法,计算了流图的环形复杂度并确定了基本测试路径,从而为每条基本路径设计了测试用例。实践证明,基本路径测试法适用于执行路径较多的程序,通过选择有代表性的路径进行测试,可有效提高测试效率。

民用机场智慧化程度评价指标的构建

为了解决民用机场在进行智能化程度评价过程中客运核心业务流基础评价指标种类繁多、覆盖范围广泛、指标间关系错综复杂的难题,从智慧程度、覆盖程度和准确程度进行了多角度耦合的基础评价指标通式构建.在此基础上,以航班流为例分别从感知型、预测型和决策型3个方面进行了基础评价指标的构建.研究结果表明,所构建的基础评价指标可根据其所涉及数据的功能属性划分为感知型指标、预测型指标、决策型指标3类,解决了智慧化程度基础评价指标缺失的问题.感知型与预测型指标可从智慧方法、覆盖程度、准确程度3个角度进行刻画,而决策型指标仅需从智慧方法、覆盖程度2个角度进行刻画,构建了多角度耦合的指标通式.从智慧方法角度划分,智慧程度可分为全智慧化管控、半智慧化管控和全人工管控3类状态,而覆盖程度与准确程度可由覆盖率与准确率表征.

人口流动对江苏省基本公共服务供给水平的门槛效应研究

人口流动是精准配置公共服务资源的重要参考。基于江苏省2008—2020年的面板数据,研究人口流动对基本公共服务供给水平的门槛效应。结果显示,人口流动对基本公共服务供给水平具有双门槛效应,即基本公共服务供给水平随人口流动规模的扩大而降低,降低幅度随着人口流动变量跨过门槛值而下降。经济发展水平与产业结构均能显著提升基本公共服务供给水平,财政自主权提升不利于公共服务供给水平的提高。

唐钢新区2922m^(3)高炉高球比生产的操作制度

唐钢新区1号高炉探索球团矿比例从19.5%提高到31%的操作制度,初步探索结果表明,高球比生产对煤气流分布的影响较大。之后,经过一年多的探索,唐钢新区2922m^(3)高炉成功实现40%以上高球比操作,主要操作经验是:根据炉况逐步提高球团矿比例,不可盲目地快速提升;调整装料制度宜采用“稳定边沿,保证中心”的思路,当出现炉墙结厚趋势时,可适当强化边沿气流进行处理,减少大幅调整装料制度;当中心气流减弱、炉缸状态下降时,可适当缩小风口面积,保证风速达到255m/s以上,提高鼓风动能;应将铁水[Si]控制在0.3%~0.4%,炉渣碱度控制在1.15~1.20,保证高炉稳定顺行。

基于Visual Basic的真空系统计算软件开发

阐述了真空系统的流态判别、流导计算及抽气时间、压力变化等计算方法,在此基础上采用Visual Basic 6.0对真空系统计算部分进行了软件开发。软件界面清晰,易于操作,便于技术人员掌握。

基于心流体验的闯关性教学法用于基础护理学教学质量持续改进中的成效

为分析基于心流体验的闯关性教学法在基础护理学教学中的应用价值,采用方便抽样的方法,选取我校21护3班40名中专生为对照组进行常规教学,21护4班40名中专生为试验组,采用基于心流体验的闯关性教学法开展基础护理学教学,对比两组学生期末成绩、护理关怀能力、学习投入情况、评判性思维能力以及受教满意度。研究表明,基于心流体验的闯关性教学法可提高学生基础护理学期末成绩,可促进学生护理关怀能力、学习投入度、评判性思维能力的提升,也可提高学生受教满意度,可推广应用。

基于Visual Basic的局域网实时语音系统的设计

详细描述使用Visual Basic编程工具,通过调用低级音频函数,实现局域网内计算机间的实时语音通信的方法。通过引入发送令牌和问候机制实现简单的流量控制,经分析和实践,达到比较理想的效果,就语音通信模式的扩展提出对策。

基于VisualBasic的新生报名系统的设计与实现

文章从软件设计的角度出发，分别从编程语言的选用，数据流图，数据库，数据表的建立等方面介绍新生报名系统的建立过程。根据需求分析设计的要求，选择相应的算法设计系统，在vb6．0应用程序的基础上，实现如何建立数据库，查询数据库，填写数据库。

社会基本医疗保险对农民工就业流动的影响研究——基于居民医保和职工医保比较的视角

农民工的就业流动是缩小城乡差距、实现共同富裕的重要途径。基于2017年全国流动人口动态监测调查数据,研究社会基本医疗保险对农民工就业流动的影响。研究发现:与职工医保相比,居民医保减少了农民工的流动时间;居民医保促进了流动3次以上的概率;与居民医保相比,职工医保促进了农民工的跨市、跨县流动。异质性结果表明,居民医保弱化了老一代农民工跨市和跨县流动,而职工医保促进了新一代农民工的跨市流动;在户籍地参加居民医保或职工医保都会对农民工就业流动产生“回拉”效果。因此,为了促进农民工就业流动以及削弱流动过程中社会基本医疗保险的牵制作用,应创造条件鼓励更多的农民工参加职工医保;提高医疗保险的统筹层次,减少医疗保险的转移接续障碍。