太阳耀斑的双带分离运动研究

太阳耀斑是最剧烈的太阳活动现象,耀斑最普遍的观测现象是耀斑带向磁中性线两侧分离.通过一个典型的太阳双带耀斑事件研究耀斑带分离运动的规律.研究发现:耀斑带的分离速度和纵向磁场是负相关的;从爆发时间上看,这种相关在耀斑峰值的时候最弱;耀斑爆发过程中,最强的重联发生在硬X射线辐射源区域.此外,在耀斑爆发期间,磁重联率和耀斑带的分离速度有相似的变化趋势.     

高阶奇异边界积分的新型求积公式

引用国内外有关奇异积分方程理论研究的较新成果,讨论了直线段上含任意阶奇异性的奇异积分的数值求积,按照奇点在单元端点和内点两种情况,分别给出了具体的求积公式。最后用本文公式计算了一个有解析结果可资对比的简单实例,表明本文格式精度高 而计算量小。     

半平面体弹性问题的边界积分公式及应用

从格林函数和双调和函数的基本解出发，将双调和方程的边值问题转化为一个只与边界面力有关的边界积分方程，进而求得具体面力条件下半平面弹性问题的解析解．并用以研究底板岩层中的应力分布，得到了底板应力增量分布的解析计算公式，该公式直观、简洁，便于进行数值计算．     

三维初应变问题中区域变量的边界型积分公式

给出了用边界单元法求解三维初应变问题时区域型变量的边界型积分公式的显式。首先将区域型变量用完全多项式展开,然后利用积分核之间的内在联系以及高阶基本解,将相应的区域型积分转化成边界型积分,并简述了边界型积分公式的应用。     

逻辑基本规律的公式表示

同一律、矛盾律和排中律是思维的三大基本规律,而目前国内大多数逻辑学教材关于同一律、矛盾律和排中律的公式表示却是错误的。就此逐一对这三大规律的公式表示所存在的问题进行了论证。结论是主张取消对同一律、矛盾律和排中律的公式表示。此外,还特别强调了三大逻辑规律作为元逻辑规则的特殊地位。     

极坐标下静磁场的非线性边界元分析(英文)

1 Introduction In rotary electric power devices, e. g. electric machines, most of field boundary are circles or circular arcs. It is difficult to handle accurately with conventional linear elements in Cartesian coordinates. In analysis of many fields, this is considered in following two simplified ways.     

太阳能级硅粉在等离子体中纯化研究

给出了本研究中所采用工业硅的要求和太阳电池功率高达14%的P型硅材料中单一杂质的阀值。针对太阳能级硅的纯化要求和工业硅的特性,提出了等离子体对硅粒“刻蚀提纯”的新概念。增加鞘层厚度将使硅粉浸泡于高动能离子中的几率增加,钝化效应消失从而达到提高纯化速率的目的。所研制的新型纯化系统能够满足硅粒自旋、长沉降时间和重复纯化的条件,所给出的工艺参数能满足鞘层宽、离子浓度高的要求。实验结果显示这种新的提纯方法可望用于太阳能级硅的制备。     

太阳直射辐射和散射辐射的模拟及分离

本文根据北京近10年太阳辐射和空气湿度资料,统计出了昙天、阴天太阳直射辐射强度与总辐射强度之间的关系。建立了识别晴天、昙天、阴天三种天气类型的模式;探讨了太阳直射辐射强度、散射辐射强度的模拟及分离方法。最后,将模拟值与实测值进行了分析比较,结果发现两者十分吻合。     

边界积分方程中强奇异积分的解法

讨论了边界积分方程的几种奇异类型．研究了３种求解强奇异积分的方法：积分核级数展开法、奇异部分分离计算法、正则化方法．     

带电圆柱面上的电场及载流圆柱面上的磁场

运用分析推理和数学计算两种方法,给出长直均匀带电圆柱面上的电场及长直载流圆柱面上的磁场,得到与高斯定斯和安培环路定律相同的结论。     

Magnetic reconnection structures in the boundary layer of an interplanetary magnetic cloud

An interplanetary magnetic diffusion region was detected by WIND during 0735-0850 UT on May 15, 1997 when the front boundary layer of a magnetic cloud passed through the spacecraft about 190 earth radii upstream of the earth. The main signals of magnetic reconnection processes are: (i) Flow reversal was detected at about 0810 UT. The counter-streaming flows have the speeds of about 65 and 41 km/s, respectively, with an angle of about 140 degree between them. (ii) Hall magnetic field was detected. The Hall fields -By and +By, perpendicular to the X-Z plane, with their magnitude up to -7.0 nT, are superposed upon a guide field about 12 nT. (iii) Alfvenic fluctuations are obviously intensified inside the reconnection region; at the front boundary of the reconnection region, a slow-mode-like discontinuity was detected.(iv) Ions are heated intensively inside the reconnection region, with their temperature three times higher than that ahead of the boundary layer; electrons are also heated, with a little enhan     

同杆并架多回输电线附近的工频电磁场

建立了同杆并架多回输电线附近工频电磁场的数学模型 ,运用计算机辅助分析软件对三相四回输电模型进行了计算 ,分析比较了线路参数变化时 ,电场强度和磁场强度的变化规律     

Fundamental solutions for transversely isotropic magneto-electro-elastic media and boundary integral formulation

Smart or intelligent materials with piezoelectric and/or piezomagnetic, due to their ability of converting energy from one form to the other(among magnetic, electric, and mechanical energies) have been widely used in such hi-tech areas as electrics, laser, supersonics, microwave, infrared, etc. Furthermore, composites made of piezoelectric/piezomagnetric materials exhibit a magneto- electric effect that is absent in single-phase piezoelectric or piezomagnetic materials[1,2]. In order to study …     

Active magnetic control algorithm for small satellite

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Response of magnetic fields at geosynchronous orbit and on the ground to the sudden changes of IMF B Z

The rapid change in the Earth’s magnetosphere caused by solar wind disturbances has been an important part of the solar wind-magnetosphere interaction.However most of the previous studies focused on the perturbation of the Earth’s magnetic field caused by solar wind dynamic pressure changes.In this paper,we studied the response of geosynchronous magnetic field and the magnetic field to the rapid southward turning of interplanetary magnetic field during the interval 1350 1420 UT on 7May 2007.During this event,BZ component of the interplanetary magnetic field decreased from 15 nT to 10 nT within 3 min(1403 1406 UT).The geosynchronous magnetic field measured by three geosynchronous satellites(GOES 10 12)first increased and then decreased.The variations of magnetic field strength in the morning sector(9 10 LT)were much larger than those in the dawn sector(5 LT).Meanwhile,the H components of geomagnetic field on the ground have similar response features but exhibit latitude and LT dependent variations.Compared with H components,the D components do not have regular variations.Although the solar wind dynamical pressure encounters small variations,the magnetic field both in space and on the ground does not display similar variations.Therefore,the increase of geomagnetic field in the dawn sector is caused by the southward turning of IMF(interplanetary magnetic field)BZ.These results will help to better understand the coupling process of geomagnetic filed and interplanetary magnetic field.     

以电磁轴承支撑挠性转子的鲁棒控制器设计

研究了含有参数不确定性的以电磁轴承支撑挠性转子的鲁棒H∞控制器，折衷考虑转子系统的外激励干扰衰减和转子系统参数摄动，将参数摄动转化为外扰动输入，建立了以电磁轴承支撑挠性转子H∞标准模型．数值仿真表明：建立的H∞标准模型合理；采用H∞控制设计的电磁轴承主动控制系统，能够有效的抑制参数摄动引起的扰动和持续的外激励干扰．     

主动磁控小卫星模糊控制算法研究

为了缩短小卫星姿态捕获的时间及提高控制精度，针对卫星入轨后的主动磁阻尼与磁捕获控制，结合磁控力矩约束条件，提出了一种模糊控制算法，针对各轴向的磁偶极子进行了控制器设计。分析结果表明，该算法在输入反馈信号数值较小时，可以显著地改善系统的灵敏度和动态特性。计算机仿真结果表明，该算法鲁棒性好，控制精度高，捕获时间相对较短。     

A new type counter electrode for dye-sensitized solar cells

A new type counter electrode for dye-sensitized solar cells (DSCs) was proposed which consists of substrate, aluminum film and platinum film. The new type counter electrode can obviously improve the photoelectric conversion efficiency of DSCs from 3.46% to 7.07% under the standard AM1.5 irradiation condition. Advantages and shortcomings of this new type counter electrode in terms of electrical properties, optical properties and anti-corrosive properties were analyzed. As a result, some improvements were proposed. Supported by the Key Foundation for Fundamental Research of Tianjin Municipal Science & Technology Commission in China ( Grant No. 06YFJZJC01700) and the National Basic Research Program of China (“973“ Project) (Grant Nos. 2006CB20260, 2006CB202603)     

磁悬浮系统自抗扰广义预测控制

针对负载扰动以及轨道“台阶”现象可能导致磁浮列车失稳的问题,将自抗扰广义预测控制（LADRC-GPC）理论引入磁浮列车悬浮系统,设计了一种新型悬浮控制器。控制器采用分层控制策略,内层利用扩张状态观测器(ESO)对系统进行动态补偿,得到被控对象的受控自回归滑动平均模型(CARMA) ,降低了对被控对象数学模型的依赖程度。外层以内层控制为被控对象,采用广义预测控制（GPC）对系统进行动态优化控制,提高了控制器的跟踪性。通过仿真和实验与PID控制算法、线性自抗扰控制（LADRC）算法比较,结果表明:自抗扰广义预测控制算法具有较好的跟踪性与鲁棒性,在较大负载扰动时仍能保持较小的误差。