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.     

Relationship between air temperature oscillations and solar variability on short and medium time scales

The contemporary science of climate change is increasingly focusing on the temporal and spatial characteristics of temperature oscillations and determining possible underlying causes.In particular,the effect of variations in solar irradiance on the variability of the climate remains a hot topic of debate.Most studies focus on the effects of solar variation on the Earth's climate on long time scales.This study presents the responses of regional climates to solar variations on shorter time scales using two da...     

基于LTL Tableau的自动机构造

基于线性时序逻辑(LTL)的模型检验是使用较为广泛的技术。该种模型检验最终归结为有穷自动机的判空问题,其复杂性来源于性质和模型乘积自动机的状态空间膨胀。作者提出了一种构造迟滞交换Co-Büchi自动机(Stuffer Alternating Co-Büchi)的具有线性复杂度的方法,该方法能够降低最终乘积自动机的空间复杂度。     

规范多agent系统动态模型及其属性验证机制

针对规范多Agent系统（NMAS）并发性、动态性和规范性的特点,提出了一种规范多Agent系统动态模型和基于模型检验的属性验证机制.其中动态模型包括行为约束规范语言TNAL和联合行为转移结构两大部分.TNAL以现实世界法律法规为参考,实现了规范的时态特性和道义特性的建模.联合行为转移结构以多Agent联合行为作为状态转移标记,以规范剪枝后的计算树描述规范系统的动态语义,使系统属性描述语言和规范语言相互独立.以CTL*作为系统属性描述语言,借助现有模型检验工具即可实现NMAS的属性验证,这种实现方式使系统验证工作具有更高的灵活性.     

基于连续小波变换的风光发电资源多尺度评估

针对区域风光发电资源评估问题,提出一种基于连续小波变换的多尺度评估方法。从美国国家航空航天局(National Aeronautics and Space Administration, NASA)中获取风速和光照强度再分析数据,并利用虚拟发电系统模型预处理为发电容量系数。综合考虑储量、波动性和互补性等资源属性,构建量化指标对区域风光发电资源进行分析,以时间和空间两个角度挖掘区域资源的分布特征。利用连续小波变换方法提取不同尺度上的风光波动性和互补性特征,评估风光互补发电对出力波动的平抑作用,并探究最佳的互补尺度。以枣庄市为例,对提出方法的有效性进行验证。算例分析表明:风光资源具有波动性和互补性,在最佳尺度上规划互补发电系统能够有效平抑功率波动。     

基于连续介质力学的形变地球重力场描述

地球重力场的时空结构与分布特性无论在基础理论研究还是在地理空间信息建设中都具有重要意义.地球表面上的观测仪器检测到的只是某一个质点的重力变化,但是理论研究却是基于引力和引力位场方程进行的.基于连续介质力学的基本理论,给出了地球密度变化、引力和引力位变化的Lagrange和Euler描述,明确了重力场变化的若干概念,它对于高精度地球重力场时空变化的理论研究具有参考价值.     

The variation of the estimated GPS instrumental bias and its possible connection with ionospheric variability

Based on the analysis of the satellite DCB data estimated by our method and the Center for Orbit Determination in Europe(CODE)from 1999 to 2011,the features of the temporal variation of differential code biases(DCB)are studied.Summarily,there are three types of variations in DCB on different time scales.The first one is the day-to-day variation that exhibits more obviously in solar maximum years.The second one is the variation with about one year periodic variation that behaves more obviously from 1999 to 2004.The last one is the monotonously descending tendency from 1999 to 2010.Considering the basic ionospheric approximation in DCB estimation method,the features of the variability of the ionospheric morphology from 1999to 2010 are also displayed based on the ionospheric characteristic parameters.It can be concluded that the day-to-day and annual variation of the estimated global positioning system(GPS).DCB is related to the ionospheric variability.The variation of DCBs on solar cycle time scale includes the real hardware DCBs and pseudo-DCBs induced by ionospheric variation.No doubt,these kinds of"pseudo"variations of DCB will affect the precision of ionospheric total electron content(TEC)derived from the GPS data.In addition,this study is helpful for evaluating the influence of ionospheric weather on TEC derivation and is also useful for developing one estimation method of DCB with more stability and precision through introducing a more practical ionospheric model.     

PSD空间定位的非线性误差补偿模型及归一化

PSD是一种高分辨率、实时性好的光电位置敏感器件，因而具有广泛的应用前景.但在光照度变化条件下，输出信号存在非线性飘移，因而影响了作为位置检测传感器的检测精度，尤其在3D测量时适用性受到了限制.针对这个问题，提出了一种PSD位置传感器的非线性误差补偿方法.该方法针对目标的空间距离变化所产生的PSD输出非线性飘移，采用归一化模型进行误差修正，很大程度上改进了PSD的输出一致性，使基于PSD的3D测量系统性能得以提高.     

Prediction method for October 2003 solar storm

Aiming at two intense shock events on October 28 and 29, 2003, this paper presents a two-step method, which combines synoptic analysis of space weather ——“observing” and quantitative prediction ——“palpating”, and then uses it to test predictions. In the first step of “observing”, on the basis of observations of the solar source surface magnetic field, interplanetary scintillation (IPS) and ACE spacecraft, we find that the propagation of the shocks is asymmetric relative to the normal direction of their solar sources, and the Earth is located near the direction of the fastest speed and the greatest energy of the shocks. As the two fast ejection shock events, the fast explosion of coronal mass of the extremely high temperature, the strong magnetic field, and the high speed background solar wind are also helpful to their rapid propagation. In the second step of “palpating”, we adopt a new membership function of the fast shock events for the ISF method. The predicted results show that for the onset time of the geomagnetic disturbance, the relative errors between the observational and the predicted results are 1.8% and 6.7%; and for the magnetic disturbance magnitude, the relative errors are 4.1% and 3.1%, re- spectively. Furthermore, the comparison among the predicted results of our two-step method with those of five other prevailing methods shows that the two-step method is advantageous. The results tell us that understanding the physical features of shock propagation thoroughly is of great importance in improving the prediction precision.     

基于相空间重构的支持向量回归机在振动数据预测中的应用

支持向量回归机是近年来发展起来的一种通用的机器学习方法,后来被广泛应用于预测领域。在对模型进行训练时,输入特征在很大程度上影响了预测的精度。所以对于特征的选择一直是人们所关注的问题。提出了一种基于相空间重构的支持向量回归机方法。该方法首先对时间序列进行相空间重构,然后利用重构的相空间中的相点作为特征输入,对模型进行训练。经实验验证,该方法能够根据时间序列内在规律,自适应的构造输入特征,提高预测结果的精度。     

The electromagnetic wave experiment for CSES mission: Search coil magnetometer

The seismic activities on the Earth can produce a disturbance of the electromagnetic field and particles in the ionosphere. The search coil magnetometer(SCM) mounted on China Seismo-Electromagnetic satellite(CSES) is designed to measure the magnetic field fluctuation of low frequency electromagnetic waves in the frequency range of 10 Hz–20 k Hz. The SCM comprises a three-axis search coil sensor mounted on a 4.5 m boom and an electronic box inside satellite module. The sampling rate of the SCM is 51.2 k Hz and the time resolution of the power spectrum density(PSD) is 2 s. The frequency resolution is 12.5 Hz.There are three operation modes: survey, detailed survey and calibration. In the survey mode, the SCM can provide a PSD in the whole frequency range of 10 Hz–20 k Hz and wave forms in the low frequency range below 2 k Hz while in the detailed survey mode the SCM can provide both PSD and wave forms in the whole frequency range of 10 Hz–20 k Hz. The sensitivity of the SCM instrument is 5.0×10~(-4) n T Hz~(-1/2) at 10 Hz, 5.0×10~(–5) n T Hz~(-1/2) at 200 Hz, 3.4×10~(-5) n T Hz~(-1/2) at 2 k Hz and 1.1×10~(-4) n T Hz~(-1/2) at 20 k Hz. The telemetry rate is ~0.85 Mbps in the survey mode and ~3.0 Mbps in the detailed survey mode. The phase difference between three axes can be made generally with a precision of less than 1.0°. The dynamic range of the SCM instrument is over 100 d B. The orthogonality of three mechanical axes of search coil senor is better than 0.13°. The performance of SCM can satisfy the requirement of scientific objectives of CSES mission.     

核设备设计地震动包络标准PSD的拟合及试验研究

核设备的抗震设计是核电厂抗震领域的一个重要问题,为了实现核电厂设备典型反应谱(RRS)匹配和标准功率谱密度(PSD)包络的设计地震动拟合,提出了一个标准PSD生成方法,该方法基于2014版《标准审查大纲》(SRP)建议的核电厂厂址设计地震动拟合方法,考虑迭代相关及随机相位谱对迭代收敛效率的影响,并通过在传统频域法拟合人...     

日全食对大地电磁场影响的研究

大地电磁测深法（Magnetotelluric,MT）是利用空间中分布广泛,频率范围很宽（10^-4～10^4Hz）的天然交变电磁场进行测量的一种频率域电磁测深法。其所直接测量的天然大地电磁场具有结构复杂性,随时间空间变化的多变性,所以研究大地电磁场的成因,组成及变化对提高大地电磁测深法的精度具有重要意义。本文通过对2009年7月22日日全食期间在武汉近郊采集的MT数据来分析研究日食效应对大地电磁场的影响,其特征表现为：①大地电磁场振幅极小值出现在食甚前约2h。②日食期间大地电磁场振幅与变化幅度都会减弱。③日食活动主要影响4～0．1Hz范围内的电磁波。     

深空探测科学仪器研究进展

深空探测是对宇宙中地球以外的行星、卫星、小行星和彗星等星体或空间环境的探测活动.合理选择深空探测科学仪器,了解被测星体的物理及化学性质、地表地貌、动态特性以及有机物和水的存在,对人类了解地外水和生命信息、认识太阳系的起源和演化有着重要意义,是深空探测的重要任务.本文总结了深空探测的科学目标,介绍了近50年来典型深空探测...     

An asynchronous and parallel time-marching method: Application to three-dimensional MHD simulation of solar wind

An asynchronous and parallel time-marching method for three-dimensional (3D) time-dependent magnetohydrodynamic (MHD) simulation is used for large-scale solar wind simulation. It uses different local time steps in the corona and the heliosphere according to the local Courant-Friedrichs-Levy (CFL) conditions. The solar wind background with observed solar photospheric magnetic field as input is first presented. The simulation time for the background solar wind by using the asynchronous method is <1/6 of that ...     

多频混凝土搅拌机的非线性动力学行为

目的提出椭圆螺旋线族轴心轨迹型拟周期运动的概念,建立混凝土搅拌机力学模型与运动微分方程,分析搅拌机的非线性动力学行为．方法将转子动力学理论、非线性振动理论和混沌振动理论用于分析混凝土搅拌机的动力学行为,利用计算机仿真的方法,在一定的具体参数下,结合波形图、轴心轨迹图、相平面图和poincare截面图,分析搅拌机系统非线性动力学行为．结果计算机仿真结果表明：当搅拌轴转速在工作转速时,在一定的具体参数下,搅拌机在运转过程中,出现混沌或拟周期运动;发现椭圆螺旋线族轴心轨迹型拟周期运动,具有主频和分频特征．结论椭圆螺旋线族轴心轨迹型拟周期运动和混沌运动,有利于提高混凝土的微观匀质性和混凝土强度．     

Asynchronous rotation scan for synthetic aperture interferometric radiometer

Synthetic aperture interferometric technique has wide applications in optics, radio astronomy and microwave remote sensing areas. With the increasing demands of high resolution imaging observation, a new time-sharing sampling scheme of asynchronous rotation scan is proposed to meet the technical challenge of achieving a large equivalent aperture and overcome the operating barriers of space borne application. This configuration is basically composed by two asynchronously and concentrically rotating antenna groups, whose revolving radii and speeds are different. The synthetic aperture system with asynchronous rotation scanning scheme can effectively solve the trade-off problem of system complexity, and greatly simplify the system hardware at the cost of sacrificing a certain time resolution. The basic rules and design methods of asynchronous rotation scan are investigated The Gridding method is introduced to inverse the spiral sampling data for image reconstruction. The potential applications of geostationary orbit (GEO) earth observation and solar polar orbit (SPO) plasma cloud observation are explored with numerical simulations to validate the significance and feasibility of this new imaging configuration. Supported by the National Natural Science Foundation of China (Grant No. 40574070, 40671121, 40701100 and 40801136) and the National High-Tech Research Program of China (“863” Program) (Grant No. 2006AA12Z141)     

多速率混合系统的模型检查

研究了初始化的多速率混合系统的模型检查问题,即检验初始化的多速率自动机是否满足某个混合区间时序逻辑公式描述的性质．首先定义了一套转换规则把混合区间时序逻辑公式转化为区间时序逻辑公式．接着定义了初始化的多速率自动机状态空间上的等价关系及其对应的域自动机,并且通过构造域自动机对应的标注有限状态自动机,把初始化的多速率混合系统的模型检查问题等价地转换成了可解的区间时序逻辑的模型检查问题．利用区间时序逻辑的模型检查算法加上上述的转换规则,就可以解决初始化的多速率混合系统的模型检查问题．     

太阳非线性无力磁场的边界积分表示公式

颜毅华和樱井2000年就太阳磁场提出了一个具有有限能量的非线性无力场模型,并对磁场给出了一个边界积分表示公式,用边界上的已知磁场值和未知的磁场法向导数值来确定空间任意点的磁场值．文中提出了一个新的直接边界积分公式,仅仅由边界上的已知磁场值确定空间点的磁场值．用颜的公式计算空间点的磁场值时,必须先求出边界上磁场的法向导数,并且求法向导数需要花较长的时间．而用新的直接边界积分公式计算空间点的磁场值时,不需要计算边界上磁场的法向导数,这样就可节省时间．相对于颜所给的公式而言,用新的公式计算磁场具有计算速度快精度高的优点．     

在线消除准-周期干扰的自适应算法

提出了一种基于锁相回路结构的自适应算法。给出了该算法的频域分析及参数设计。该算法可在线估测出准 周期干扰信号的相位及幅值,并能消除准 周期干扰的影响,可被直接嵌入工业控制器而无需改变控制器的结构。通过在卷绕传输系统中的应用验证了该自适应算法能很好地估测出干扰信号的参数,并能有效地抑制准 周期干扰的影响。