Numeric simulations of in situ observations of interacting ejecta near 1 AU

We use a simple numerical model (González-Esparza, J.A., Santillán, A., Ferrer, J. A numerical study of the interaction between two ejecta in the interplanetary medium: one and two dimensional hydrodynamic simulations, Ann. Geophys. 22, 3741–3749, 2004) to study the evolution of three events in the solar wind reported by Wang et al. (Wang, Y.M., Ye, P.Z., Wang, S. Multiple magnetic clouds: several examples during March–April 2001. J. Geophys. Res. 108, 1370, 2003, doi:10.1029/2003JA009850), where two interacting ejecta detected in situ by ACE near 1 AU were related to CMEs observed previously by SOHO-LASCO. The study is based on a 1-D hydrodynamic model using the ZEUS code (Stone, J.M., Norman, M. ZEUS 2-D: A radiation magnetohydrodynamics code for astrophysical flows in two dimensions, I, the hydrodynamics algorithms and tests, Astrophys. J. 80, 753, 1992). Although this model cannot address either the magnetic field dynamics or the complex geometrical effects intrinsic in the three-dimensional nature of the phenomena, it illuminates the transferring of momentum and evolution of interacting large-scale solar wind disturbances in those cases where there is no merging (magnetic reconnection) between the two ejecta. This model can reproduce, in some cases, characteristics of the events such as transit times and flow signatures as inferred from the two-point measurements from spacecraft.     

基于应用识别的P2P蠕虫检测

对等网中基于漏洞传播的P2P蠕虫是严重的安全威胁.根据P2P蠕虫的传播特点,提出了一种P2P蠕虫检测方法PWD (P2P Worm Detection).PWD主要由基于应用识别技术的预处理和基于未知蠕虫检测技术的P2P蠕虫检测2部分组成,改进了干扰流量的识别和过滤规则,提出了P2P蠕虫检测规则,并引进博弈论的研究方法讨论了检测周期的选取问题.仿真结果和局域网环境下的实验结果都表明,PWD是检测P2P蠕虫和遏制其传播的有效方法.      

CME-geometry and cosmic-ray anisotropy observed by a prototype muon detector network

We analyze the cosmic-ray anisotropy observed by a prototype network of muon detectors during geomagnetic storms associated with coronal mass ejections (CMEs). The network currently consists of multidirectional surface muon detectors at Nagoya (Japan) and Hobart (Australia), together with a prototype detector at São Martinho (Brazil) which has been in operation since March, 2001. In this report, we analyze the anisotropy recorded in both the muon detector and neutron monitor (the Spaceship Earth) networks and find significant enhancements of cosmic-ray anisotropy during geomagnetic storms. Following the analysis by Bieber and Evenson [Bieber, J.W., Evenson, P. CME geometry in relation to cosmic ray anisotropy. Geophys. Res. Lett. 25 (1998) 2955–2958] for the neutron monitor data at 10 GeV, we also derive cosmic-ray density gradients from muon data at higher-energy (50 GeV), possibly reflecting the larger-scale geometry of CMEs causing geomagnetic storms. We particularly find in some events the anisotropy enhancement clearly starting prior to the storm onset in both the muon and neutron data. This is the first result of the CME-geometry derived from simultaneous observations of the anisotropy with networks of multidirectional muon detectors and neutron monitors.     

一种基于P2P网络的语义Web服务发现机制

针对如何高效而又准确地发现分布于各地Web服务的问题,基于P2P网络和语义描述提出一种新型服务发现机制,将服务按照语义动态地注册于由委托(broker)管理的不同节点簇,并将语义相似的节点簇组成虚拟语义网,提高了查询效率;采用反馈机制主动监测拓扑节点,和利用节点簇之间的分裂与聚合机制来保证该模型的有效性和性能.最后通过对原型系统的实现证明了该机制的合理性与有效性.      

CME–flare association during the 23rd solar cycle

The relation between coronal mass ejections (CMEs) and solar flares are statistically studied. More than 10,000 CME events observed by SOHO/LASCO during the period 1996–2005 have been analyzed. The soft X-ray flux measurements provided by the Geostationary Operational Environmental Satellite (GOES), recorded more than 20,000 flares in the same time period. The data is filtered under certain temporal and spatial conditions to select the CME–flare associated events. The results show that CME–flare associated events are triggered with a lift-off time within the range 0.4–1.0 h. We list a set of 41 CME–flare associated events satisfying the temporal and spatial conditions. The listed events show a good correlation between the CME energy and the X-ray flux of the CME–flare associated events with correlation coefficient of 0.76.     

非均匀双流等离子体中波传播耦合波动方程

我们利用麦克斯韦方程组和矩方程组,研究了非均匀双流等离子体在电流源作用下,激发波的耦合过程。给出了三模[P_e,P_i,E_o]耦合的普遍方程▽2[P]-[C]·▽[P]+[K2][P]=[D][▽·(ω_p2E_o)]。作为一特例,本文首先研究了均匀、有损失(v≠0)双流等离子体中,等离子体波的耦合过程。指出v≠0,即使在均匀等离子体中,也将产生电子等离子体波和离子等离子体波间耦合。但不出现光学模和等离子体模间耦合。      

基于半无码的P(Y)码自相关GNSS-R海面测高方法

针对传统GPS C/A码延迟测高方法测高精度低和互相关测高方法时延波形信噪比低的问题,研究了基于半无码的P（Y）码自相关海面测高方法。首先,通过理论测高精度模型,对比分析了C/A码和P（Y）码的测高精度;然后,描述了L1、L2双频反射信号基于半无码的P（Y）码自相关处理架构,并论述了测高模型和L1、L2双频电离层时延误差修正方法;最后,利用模拟的L1、L2反射信号对比分析了基于半无码的P（Y）码自相关、C/A码自相关以及信号互相关方法的海面测高精度。结果表明:相比于C/A码自相关和信号互相关测高精度,基于半无码的P（Y）码自相关的测高精度分别提高了3.97倍和1.47倍。      

Propagation and interaction of interplanetary transient disturbances. Numerical simulations

We study the heliocentric evolution of ICME-like disturbances and their associated transient forward shocks (TFSs) propagating in the interplanetary (IP) medium comparing the solutions of a hydrodynamic (HD) and magnetohydrodynamic (MHD) models using the ZEUS-3D code [Stone, J.M., Norman, M.L., 1992. Zeus-2d: a radiation magnetohydrodynamics code for astrophysical flows in two space dimensions. i – the hydrodynamic algorithms and tests. Astrophysical Journal Supplement Series 80, 753–790]. The simulations show that when a fast ICME and its associated IP shock propagate in the inner heliosphere they have an initial phase of about quasi-constant propagation speed (small deceleration) followed, after a critical distance (deflection point), by an exponential deceleration. By combining white light coronograph and interplanetary scintillation (IPS) measurements of ICMEs propagating within 1 AU [Manoharan, P.K., 2005. Evolution of coronal mass ejections in the inner heliosphere: a study using white-light and scintillation images. Solar Physics 235 (1–2), 345–368], such a critical distance and deceleration has already been inferred observationally. In addition, we also address the interaction between two ICME-like disturbances: a fast ICME 2 overtaking a previously launched slower ICME 1. After interaction, the leading ICME 1 accelerates and the tracking ICME 2 decelerates and both ICMEs tend to arrive at 1 AU having similar speeds. The 2-D HD and MHD models show similar qualitative results for the evolution and interaction of these disturbances in the IP medium.     

量子点与TiO2电极参数对光阳极电子寿命及性能影响

通过对P25Ti O2光阳极薄膜厚度、敏化的量子点种类及量子点敏化方法研究,探讨了使用连续离子层吸附反应法的敏化方法(SILAR)时,P25Ti O2薄膜厚度与光阳极电子寿命的关系,以及量子点种类、共敏化工艺对光阳极光电性能的影响.采用电化学阻抗(EIS)、开路电压衰减(OCVD)及紫外-可见吸收方法,对影响光阳极光电性能的Ti O2薄膜厚度、量子点种类及共敏化工艺因素进行测试分析.实验结果表明:当光阳极薄膜厚度为12μm时,电子复合几率最小,光阳极的电子寿命相对最长;采用连续离子层吸附反应法(SILAR)对多种量子点共敏化的光阳极(Ti O2/Cd S/Cd Se/Zn S)与单一量子点敏化的光阳极(Ti O2/Cd S)相比,短路电流提高了34%,光转换效率提高了42%;合适的共敏化工艺也有助于提高光阳极的电子寿命、光谱吸收范围和吸收强度.     

A statistical study of CME-associated flare during the solar cycle 24

We investigate on the relationship between flares and coronal mass ejections (CMEs) in which a flare started before and after the CME events which differ in their physical properties, indicating potentially different initiation mechanisms. The physical properties of two types flare-correlated CME remain an interesting and important question in space weather. We study the relationship between flares and CMEs using a different approach requiring both temporal and spatial constraints during the period from December 1, 2008 to April 30, 2017 in which the CMEs data were acquired by SOHO/LASCO (Solar and Heliospheric Observatory/Large Angle Spectrometric Coronagraph) over the solar cycle 24. The soft X-ray flare flux data, such as flare class, location, onset time and integrated flux, are collected from Geostationary Environmental satellite (GOES) and XRT Flare catalogs. We selected 307 CMEs-flares pairs applying simultaneously temporal and spatial constraints in all events for the distinguish between two associated CME-flare types. We study the correlated properties of coincident flares and CMEs during this period, specifically separating the sample into two types: flares that precede a CME and flares that follow a CME. We found an opposite correlation relationship between the acceleration and velocity of CMEs in the After- and Before-CMEs events. We found a log-log relation between the width and mass of CMEs in the two associated types. The CMEs and flares properties show that there were significant differences in all physical parameters such as (mass, angular width, kinetic energy, speed and acceleration) between two flare-associated CME types.     

基于对等网络的自适应安全协作框架研究

提出一种新型的基于对等网络架构的无集中的安全协作框架.灵活有效地支持多种安全服务,如安全管理、安全数据的存储和共享、安全信息发布等;给出了一种适应大规模动态网络环境的支持管理结构自动构造和安全组件自配置的层次和对等方式混合的安全管理方法;基于P2P(Peer-to-Peer)网络的动态特性实现了安全协作框架对于节点变化和安全协作需求的自适应;无集中的结构消除了集中管理的性能和带宽瓶颈,在网络攻击状态下有较强生存能力.      

Simulation of cometary jets in interaction with the solar wind

The influence of cometary jets on the solar wind interaction is studied with a 3D hybrid simulation. Anisotropic outgassing patterns were until recently not considered in cometary simulations, despite strong anisotropies found at observations. Comet 67P Churyumov–Gerasimenko, the target of the ROSETTA mission, was chosen as a case study for a simulation series. The cometary outgassing at 2.7 AU is modeled to originate from a single sun-facing jet with different levels of collimation, from isotropy to extremely thin jets. As no bow shock is present at this distance, solar wind patterns resulting from the anisotropic outgassing become more apparent. We find narrower jets to increase the standoff distance of the plasma interaction structures. Also, the Mach cone is wider and stronger for certain jet profiles. The magnetic field remains unable to propagate through the coma, resulting in strong draping patterns for narrow jets due to the increased standoff distance.     

SMESE: A SMall Explorer for Solar Eruptions

The SMall Explorer for Solar Eruptions (SMESE) mission is a microsatellite proposed by France and China. The payload of SMESE consists of three packages: LYOT (a Lyman imager and a Lyman coronagraph), DESIR (an Infra-Red Telescope working at 35–80 and 100–250 μm), and HEBS (a High-Energy Burst Spectrometer working in X- and γ-rays).

The status of research on flares and coronal mass ejections is briefly reviewed in the context of on-going missions such as SOHO, TRACE and RHESSI. The scientific objectives and the profile of the mission are described. With a launch around 2012–2013, SMESE will provide a unique tool for detecting and understanding eruptions (flares and coronal mass ejections) close to the maximum phase of activity.     

Short term topological changes of coronal holes associated with prominence eruptions and subsequent CMEs

We study the short-term topological changes of equatorial and polar coronal hole (CH) boundaries, such as a variation of their area and disintegration, associated to reconnection with nearby (within 15° distance) quiescent prominence magnetic fields leading to eruptions and subsequent Coronal Mass Ejections (CMEs). The examples presented here correspond to the recent solar minimum years 2008 and 2009. We consider a temporal window of one day between the CH topological changes and the start and end times of prominence eruptions and onset of CMEs. To establish this association we took into account observational conditions related to the instability of prominence/filaments, the occurrence of a CME, as well as the subsequent evolution after the CME. We found an association between short-term local topological changes in CH boundaries and the formation/disappearance of bright points near them, as well as, between short-term topological changes within the whole CH and eruptions of nearby quiescent prominences followed by the appearance of one or more CMEs.     

飞机座舱显示界面脑力负荷测量与评价

脑力负荷是影响飞行安全的重要因素之一,对飞行员脑力负荷进行客观测量,对于飞机座舱显示界面脑力任务的工效评价与优化设计具有重要意义.基于ERP（Eveat Related Potential）技术,选取失匹配负波（MMN,Mismatch Negativity）和P3a成分为指标,采用三刺激“oddball”模式,在飞行模拟任务条件下开展了三级脑力负荷的测量与评价研究.实验结果表明,MMN峰值和P3a峰值对脑力负荷变化敏感,随着脑力负荷的增加,MMN峰值显著增加,而P3a峰值显著降低,反应了被试者对异常信息的自动加工能力的提高以及朝向注意能力的减弱.与新异刺激相比,由偏差刺激所诱发的MMN与P3a成分对于与飞行任务相关的脑力负荷具有更好的敏感性,将可用于进一步的脑力负荷分级评价.      

Interplanetary coronal mass ejections during the descending cycle 23: Sheath and ejecta properties comparison

We have used Omniweb data in order to identify the sheath and the ejecta boundaries of 67 shock-driving interplanetary coronal mass ejections during the time period 2003–2006. We examine and compare their statistical properties (speed, magnetic field strength, proton density and temperature, proton plasma beta), with those of the typical solar wind. We also calculate their passage time and radial width. We study the correlation between the ejecta and sheath characteristics.     

Solar flares,CMEs and solar energetic particle events during solar cycle 24

We present here a study of Solar Energetic Particle Events (SEPs) associated with solar flares during 2010–2014 in solar cycle 24. We have selected the flare events (≥GOES M-class), which produced SEPs. The SEPs are classified into three categories i.e. weak (proton intensity?≤?1?pfu), minor (1?pfu?<?proton intensity?<?10?pfu) and major (proton intensity?≥?10?pfu). We used the GOES data for the SEP events which have intensity greater than one pfu and SOHO/ERNE data for the SEP event less than one pfu intensity. In addition to the flare and SEP properties, we have also discussed different properties of associated CMEs.     

Regional 4-D modeling of the ionospheric electron density

The knowledge of the electron density is the key point in correcting ionospheric delays of electromagnetic measurements and in studying the ionosphere. During the last decade GNSS, in particular GPS, has become a promising tool for monitoring the total electron content (TEC), i.e., the integral of the electron density along the ray-path between the transmitting satellite and the receiver. Hence, geometry-free GNSS measurements provide informations on the electron density, which is basically a four-dimensional function depending on spatial position and time. In addition, these GNSS measurements can be combined with other available data including nadir, over-ocean TEC observations from dual-frequency radar altimetry (T/P, JASON, ENVISAT), and TECs from GPS-LEO occultation systems (e.g., FORMOSAT-3/COSMIC, CHAMP) with heterogeneous sampling and accuracy.     

Evolution of coronal mass ejections in the early stage

This work reports the investigation of two coronal mass ejections (CME) observed in white light, H, EUV and X-ray by various instruments both in space and on ground on February 18, 2003 and January 19, 2005, respectively. The white light coronal images show that the first CME began with the rarefaction of a region above the solar limb and was followed by the formation of its leading edge at the boundary of the rarefying region at altitude of 0.46 R from the solar surface. The rarefaction coincided the slow rising phase of the filament eruption, and the CME leading edge was observed to form as the filament eruption started to accelerate apparently. In the early stage of the second CME, a bright loop was first observed above the solar limb with height of 0.37 R in EUV images. We found that the more gradual CMEs initial process, the larger the timing difference between CMEs and their associated flares. The lower part of the filament brightened in H images as the filament rose to a certain height. These brightenings imply that the filament may be heated by magnetic reconnection below the filament in the early stage of the eruption. We suggest that the possible mechanism which led to the formation of the CME leading edge and cavity is magnetic reconnection which occurred under the filament when it reached a certain height.