一类椭圆型方程Cauchy问题的正则化(英文)

ＲＥＧＵＬＡＲＩＺＡＴＩＯＮＯＦＡＣＡＵＣＨＹＰＲＯＢＬＥＭＦＯＲＡＥＬＬＩＰＴＩＣＥＱＵＡＴＩＯＮ＊ＸｕＤｉｎｇｈｕａ１）ＬｉＭｉｎｇｚｈｏｎｇ２）１）ＤｅｐａｒｔｍｅｎｔｏｆＦｕｎｄａｍｅｎｔａｌＣｏｕｒｓｅｓ,ＥａｓｔＣｈｉｎａＧｅｏｌｏｇｉｃ...     

THE MOTION PROPERTIES OF THE STARS CONFINED TO THE SYMMETRIC AXIS OF AN OSCILLATION KUZMIN DISK

ＴＨＥＭＯＴＩＯＮＰＲＯＰＥＲＴＩＥＳＯＦＴＨＥＳＴＡＲＳＣＯＮＦＩＮＥＤＴＯＴＨＥＳＹＭＭＥＴＲＩＣＡＸＩＳＯＦＡＮＯＳＣＩＬＬＡＴＩＯＮＫＵＺＭＩＮＤＩＳＫＦｕＹａｎｎｉｎｇ１，２）ＳｕｎＹｉｓｕｉ１）（１）ＤｅｐａｒｔｍｅｎｔｏｆＡｓｔｒｏｎ...     

APPROXIMATE SOLUTIONS OF SOME BOUNDARY VALUE PROBLEMS FOR PARABOLIC EQUATIONS AND THEIR ERROR ESTIMATES

ＡＰＰＲＯＸＩＭＡＴＥＳＯＬＵＴＩＯＮＳＯＦＳＯＭＥＢＯＵＮＤＡＲＹＶＡＬＵＥＰＲＯＢＬＥＭＳＦＯＲＰＡＲＡＢＯＬＩＣＥＱＵＡＴＩＯＮＳＡＮＤＴＨＥＩＲＥＲＲＯＲＥＳＴＩＭＡＴＥＳＨｕＭｉｎｄｅ（胡敏德）；ＷｅｎＧｕｏｃｈｕｎ（闻国椿）（Ｌｏｇｉｓｔ...     

MAGNETIC RELAXATION AT EARLY TIMES AND FLUX DIFFUSION BARRIER V（J，B，T） FOR Ti－1223 DOPED WITH Pb AND Ba BY COMPLEX AC SUSCEPTIBILITY MEASUREMENTS

ＭＡＧＮＥＴＩＣＲＥＬＡＸＡＴＩＯＮＡＴＥＡＲＬＹＴＩＭＥＳＡＮＤＦＬＵＸＤＩＦＦＵＳＩＯＮＢＡＲＲＩＥＲＶ（Ｊ，Ｂ，Ｔ）ＦＯＲＴｉ－１２２３ＤＯＰＥＤＷＩＴＨＰｂＡＮＤＢａＢＹＣＯＭＰＬＥＸＡＣＳＵＳＣＥＰＴＩＢＩＬＩＴＹＭＥＡＳＵＲＥＭＥＮＴＳＤ...     

A COMPARATIVE STUDY OF THE TWO TRANSLATIONS OF MOONLIGHT ON THE LOTUS POND

ＡＣＯＭＰＡＲＡＴＩＶＥＳＴＵＤＹＯＦＴＨＥＴＷＯＴＲＡＮＳＬＡＴＩＯＮＳＯＦＭＯＯＮＬＩＧＨＴＯＮＴＨＥＬＯＴＵＳＰＯＮＤ①ＬｉｕＸｉａｏｈｕａⅠ．ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｉｓｐａｐｅｒｉｓｉｎｔｅｎｄｅｄｔｏｍａｋｅａｃｏｍｍｐａｒａｔｉｖｅ...     

MIXED BOUNDARY VALUE PROBLEM FOR SECOND ORDER SYSTEM OF DIFFERENTIAL EQUATIONS OF THE ELLIPTIC TYPE

ＭＩＸＥＤＢＯＵＮＤＡＲＹＶＡＬＵＥＰＲＯＢＬＥＭＦＯＲＳＥＣＯＮＤＯＲＤＥＲＳＹＳＴＥＭＯＦＤＩＦＦＥＲＥＮＴＩＡＬＥＱＵＡＴＩＯＮＳＯＦＴＨＥＥＬＬＩＰＴＩＣＴＹＰＥＣｈｅｎＱｉｎｇｘｉａｎｇ（陈庆祥）（ＺｈｏｎｇｓｈａｎＵｎｉｖｅｒｓｉｔｙ，Ｇ...     

DISK ACCRETION ONTO MAGNETIC NEUTRON STARS

ＤＩＳＫＡＣＣＲＥＴＩＯＮＯＮＴＯＭＡＧＮＥＴＩＣＮＥＵＴＲＯＮＳＴＡＲＳ￥ＬｉＸｉａｎｇｄｏｎｇ；ＷａｎｇＺｈｅｎｒｕ（ＤｅｐａｒｔｍｅｎｔｏｆＡｓｔｒｏｎｏｍｙ，ＮａｎｊｉｎｇＵｎｉｖｅｒｓｉｔｙ，２１００９３，Ｎａｎｊｉｎｇ，ＰＲＣ）Ｋｅｙｗｏ...     

THE OBLIQUE DERIVATIVE BOUNDARY VALUE PROBLEM FOR ELLIPTIC COMPLEX EQUATIONS OF FOURTH ORDER

ＴＨＥＯＢＬＩＱＵＥＤＥＲＩＶＡＴＩＶＥＢＯＵＮＤＡＲＹＶＡＬＵＥＰＲＯＢＬＥＭＦＯＲＥＬＬＩＰＴＩＣＣＯＭＰＬＥＸＥＱＵＡＴＩＯＮＳＯＦＦＯＵＲＴＨＯＲＤＥＲＹａｎｇＧｕａｎｇｗｕＸｕＫｅｍｉｎｇ（杨广武）（许克明）（ＨｅｂｅｉＵｎｉｖｅｒｓｉｔｙ...     

ON THE EXPONENT SET OF PRIMITIVE LOCALLY SEMICOMPLETE DIGRAPHS

ＯＮＴＨＥＥＸＰＯＮＥＮＴＳＥＴＯＦＰＲＩＭＩＴＩＶＥＬＯＣＡＬＬＹＳＥＭＩＣＯＭＰＬＥＴＥＤＩＧＲＡＰＨＳ￥ＺｈａｎｇＫｅｍｉｎｇ１）；ＢｕＹｕｅｈｕａ２）（１）ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｃｍａｔｉｅｓ，ＮａｎｊｉｎｇＵｎｉｖｅｒｓｉｔｙ，Ｎ...     

MICROSPHERULESINSUZHOUGRANITE：ABLATEDPRODUCTSOFACOMETARYEXPLOSION

ＭＩＣＲＯＳＰＨＥＲＵＬＥＳＩＮＳＵＺＨＯＵＧＲＡＮＩＴＥ：ＡＢＬＡＴＥＤＰＲＯＤＵＣＴＳＯＦＡＣＯＭＥＴＡＲＹＥＸＰＬＯＳＩＯＮＨｕＺｈｏｎｇｗｅｉ１）ＷａｎＹｕｑｉｕ２）ＷａｎｇＥｒｋａｎｇ２）（１）ＤｅｐａｒｔｍｅｎｔｏｆＡｓｔｒｏｎｏｍｙ，...     

圆柱空腔内旋转流动涡破裂随Re变化的实验研究

针对旋转封闭圆柱空腔内的轴对称涡破裂现象,设计了可变旋转Ｒｅ实验系统。实验中空腔高径比Ｈ／Ｒ＝１．７８。采用激光相位多普勒测量技术测量了圆柱空腔轴线上轴向速度分量分布随Ｒｅ变化的情况,定量观测和分析了涡破裂现象的发生、发展过程,测量到涡破裂现象出现和消失这两种临界状态２。     

Mesoscopic superconductor as a ballistic quantum switch.

Several key experiments have revealed a rich variety of vortex structures in mesoscopic superconductors in which only a few quanta of magnetic flux are trapped: these structures are polygon-like vortex 'molecules' and multi-quanta giant vortices. Ginzburg-Landau calculations confirmed second-order phase transitions between the giant vortex states and stable molecule-like configurations. Here we study theoretically the electronic structure and the related phase-coherent transport properties of such mesoscopic superconductor systems. The quasiparticle excitations in the vortices form coherent quantum-mechanical states that offer the possibility of controlling the phase-coherent transport through the sample by changing the number of trapped flux quanta and their configuration. The sample conductance measured in the direction of the applied magnetic field is determined by the transparency of multi-vortex configurations, which form a set of quantum channels. The transmission coefficient for each channel is controlled by multiple Andreev reflections within the vortex cores and at the sample edge. These interference phenomena result in a stepwise behaviour of the conductance as a function of the applied magnetic field, and we propose to exploit this effect to realize a vortex-based quantum switch where the magnetic field plays the role of the gate voltage.     

A one-dimensional chain state of vortex matter.

Magnetic flux penetrates isotropic type II superconductors in flux-quantized vortices, which arrange themselves into a lattice structure that is independent of the direction of the applied field. In extremely anisotropic high-transition-temperature (high-Tc) superconductors, a lattice of stacks of circular 'pancake' vortices forms when a magnetic field is applied perpendicular to the copper oxide layers, while an orthogonal elongated lattice of elliptical Josephson vortices forms when the applied field is parallel to the layers. Here we report that when a tilted magnetic field is applied to single crystals of Bi2Sr2CaCu2O8+delta, these lattices can interact to form a new state of vortex matter in which all stacks of pancake vortices intersect the Josephson vortices. The sublattice of Josephson vortices can therefore be used to manipulate the sublattice of pancake vortices. This result explains the suppression of irreversible magnetization by in-plane fields as seen in Bi2Sr2CaCu2O8+delta crystals, a hitherto mysterious observation. The ability to manipulate sublattices could be important for flux-logic devices, where a 'bit' might be represented by a pancake vortex stack, and the problem of vortex positioning is overcome through sublattice interactions. This also enables the development of flux transducers and amplifiers, considerably broadening the scope for applications of anisotropic high-Tc superconductors.     

船用螺旋桨盘前方诱导速度计算

提出了计算船用螺旋桨盘前方诱导速度场的计算模型及方法。假定桨前方诱导速度可由三部分组成，即ｕ＝ｕＬ＋ｕｂ－ｕＦ，ｕＬ为由 Ｌｅｒｂｓ诱导因子法所计算的诱导速度；ｕＦ为由场点至桨盘处自由涡系在场点处所产生的诱导速度；ｕｂ为桨盘处附着涡在场点处所产生的诱导速度。这三部分诱导速度计算均十分简单，从而避免了由桨盘处开始向后泄向无穷远处自由涡系在场点处所产生的诱导速度计算时所必须进行的一无限数值积分，计算方法中计入了桨叶有限叶数的影响。所作实例计算与试验结果比较，吻合良好。     

三维水翼初始梢涡空泡数的尺度效应

针对梢涡流场和初始梢涡空泡数的尺度效应问题,利用大涡模拟(LES)湍流模型对三维水翼的梢涡流场流速进行模拟计算;为减少误差,对梢涡流域网格进行了局部加密处理,对未发生空化时梢涡内的轴向速度和切向速度进行计算.结果表明,LES湍流模型的流场流速计算结果与实验值吻合较好.同时,介绍了经典初始梢涡空泡数尺度效应公式的推导过程,并利用数值计算的速度环量和涡核半径修正尺度效应公式.     

Energy dispersion of complex non-isolated vortices

Energy dispersion is a fundamental scientific problem in the study of natural disasters such as typhoons, heavy rain and earthquakes. The problem has been addressed by both multi-discipline research and forecast studies. The dynamics of isolated circular vortex energy dispersion have been solved. However, the disastrous results of typhoons and heavy rain often occur due to non-isolated circular vortices, the dynamics of which are explored in this paper. The energy dispersion characteristics of non-isolated vortices with complex structural patterns are examined using a linearized nondivergent barotropical vorticity equation model. In the initial field, a tropical cyclone (TC) vortex and a meso-scale vortex coexist, forming a complex structural pattern. An analytic solution based on a Fourier transform and simulations using a two-dimensional model show the following. (1) A wave train of TC-G-D may be created by the energy dispersion where the line connecting the three member centers of the wave train is parallel to the x axis in the case of an initial TC vortex without a meso-scale vortex. (2) A wave train of TC-G-D may also be created by energy dispersion. However, the line connecting the three member centers of the wave train would no longer be parallel to the x axis. Instead, they would form a triangle in the presence of the initial TC vortex with the meso-scale vortex. (3) There is a nonlinear relationship between the initial intensity of the meso-scale vortex and the base angle of the triangle. These results have the potential to be applied in the field of typhoon forecasting.     

不同侧风类型影响下的飞机尾涡数值模拟研究

在航空飞行中,低空风切变极易对处在起飞爬升或进近着陆阶段的飞机带来安全隐患,严重时会导致飞机失速甚至坠毁。低空风切变往往还具有持续时间短、尺度小、突发性强等特点。因此在中国民航和通用航空业高速发展的背景下,加强对飞机遭遇低空风切变的数值模拟仿真和研究具有重要意义和实际价值。采用SST模型并使用FLUENT计算尾涡演化,通过构建H-B尾涡耗散二维模型,应用ANSYS FLUENT UDF(user defined function)编译环境侧风不同的7种情况进行尾涡耗散机理的数值模拟,通过对比成都双流机场实地探测的尾涡发现在非线性垂直切变影响下侧风和涡诱导速度的叠加会导致尾涡对周围的压力分布不对称,引起尾涡对倾斜。     

C形起动时鱼尾模型的流场结构

在活鱼观察实验的基础上,用对称和非对称两种模型模拟了鱼类尾鳍C形起动时周围的流场结构,测量了模型受到的力和力矩.通过氢气泡和PIV方法研究了对称和非对称尾鳍C形起动时产生的旋涡结构特征;通过涡量矩理论定性分析了旋涡流场结构与C形起动模型动力学特征的关联.     

涡流发生器对3/4汽车模型风洞流场品质的影响

采用数值计算的方法对3/4开口回流式汽车风洞喷口处的涡流发生器进行了研究.对比研究了三种不同片数的涡流发生器对流场品质的影响.首先采用定常雷诺时均纳维斯托克斯方程求解了流场的定常特性,接着采用大涡模拟(LES)方法对流场的非定常特性进行了研究.并就两种计算方法给予了相应的试验验证.对比计算结果得到涡流发生器可以在一定程度上提高流场均与性,尤其是三片式涡流发生器的工况能较好地拓宽风洞测试区的高流速区域的范围,降低测试区的静压梯度,减小试验段内的湍流度和剪切层内的湍流度,延长测试段内低湍流区的长度,分散流场内的脉动能量,降低低频颤振敏感频率区的能量聚集.     

Observation of individual vortices trapped along columnar defects in high-temperature superconductors

Many superconductors do not entirely expel magnetic flux-rather, magnetic flux can penetrate the superconducting state in the form of vortices. Moving vortices create resistance, so they must be 'pinned' to permit dissipationless current flow. This is a particularly important issue for the high-transition-temperature superconductors, in which the vortices move very easily. Irradiation of superconducting samples by heavy ions produces columnar defects, which are considered to be the optimal pinning traps when the orientation of the column coincides with that of the vortex line. Although columnar defect pinning has been investigated using macroscopic techniques, it has hitherto been impossible to resolve individual vortices intersecting with individual defects. Here we achieve the resolution required to image vortex lines and columnar defects in Bi2Sr2CaCu2O8+delta (Bi-2212) thin films, using a 1-MV field-emission electron microscope. For our thin films, we find that the vortex lines at higher temperatures are trapped and oriented along tilted columnar defects, irrespective of the orientation of the applied magnetic field. At lower temperatures, however, vortex penetration always takes place perpendicular to the film plane, suggesting that intrinsic 'background' pinning in the material now dominates.