FY2D卫星与GOES卫星空间粒子观测结果的对比分析

风云二号D星(FY2D)搭载的空间粒子探测器可以观测10～300 MeV的质子和≥350 keV与≥2 MeV的电子.卫星在轨测试阶段,空间粒子探测器观测到了空间环境宁静期间地球同步轨道的电子昼夜周期变化的典型特征,并在卫星发射后的12月15日首次观测到了有代表性的 2级太阳质子事件(SEP),观测到的较高能量质子比较低能量质子更快地恢复到平静时的状态.通过比较FY2D卫星与GOES卫星的探测结果,既显示了同步轨道区域不同位置高能电子通量扰动时间的一致性,也显示了高能电子通量具强烈的晨昏不对称性.通过对太阳质子事件和地磁平静时期该轨道空间高能粒子环境特征的分析和研究,并与GOES卫星同期的观测结果进行相关性分析,结果表明仪器确实具备了监测空间环境扰动和预警能力,探测结果可以用于研究地球同步轨道粒子空间分布、起源和传输等科学目的.     

地震前兆与短临预报探索

针对地震短临预报面临的科学问题,分析研究了地震前兆(近场前兆、远场前兆和大尺度动态前兆)预报地震的物理基础;总结了地震短临前兆时空演化特征和同步耦合现象。高空技术在地震前兆观测中的应用将有利于短临预报实践与探索。     

望儿山金矿床控矿剪切带的空间结构特征

望儿山控矿剪切带由韧性构造和脆性构造、石英脉金矿体和蚀变岩金矿体组成，它们在空间上出现有序的变化规律。从研究构造岩、构造形态及组合样式、节理的优选性和构造运动差异性等方面特征；认为望儿山剪切带控制着金矿床的形成、就位和富集规律。     

介绍大型矿集区的一种富集模式:多重圈闭等温场模式——以铜陵狮子山矿田为例

狮子山矿田是安徽铜陵地区乃至长江中下游地区重要的矿田之一。该矿田目前已探明铜、金等大中小型矿床十多处,按赋存标高自下而上依次为:冬瓜山深部斑岩Cu、冬瓜山Cu、胡村Cu、花树坡Cu、大团山Cu(Au)、老鸦岭Cu、东、西狮子Cu(Au)、鸡冠石Ag、Au、Cu、Pb、Zn,包村Au(Cu)、白芒山Au等矿床,达到大型-超大型规模,引起了国内外矿床地质学家的广泛关注。近年来又发现并勘查出几个独立岩金矿床,且在矿田深部1000多米处又发现了新的矿体,标志着该区找矿工作进入了一个新的阶段。多种矿床类型共存,铜矿与金矿配对,矿床(体)呈多层产出,是矿田的显著特色。矿田内业已发现矽卡岩型、层控矽卡岩型、斑岩型、中低温热液型和风化—淋滤型等矿床;既有以内生作用为主,又有以沉积作用为主的矿床,及二者的复合类型;铜、金可共生、伴生,也可形成各自独立的矿床;自深部斑岩铜矿至C2+3—T2中层状、脉状矿床,成矿垂深大。它们虽产于不同层位的地层中,主要表现为多层楼成矿特点,但其产出受统一构造、岩浆岩等多重圈闭因素制约而构成的统一的等温的岩浆-流体-成矿系统之中。在某种意义上说,狮子山矿田是铜陵地区乃至整个长江中下游成矿带的缩影和典...     

GPS-LEO掩星探测现状和展望

20世纪80年代美国科学家提出利用GPS系统探测地球大气,诞生了GPS气象学。GPS气象学分为地基GPS气象学和空基GPS气象学,目前地基GPS气象学在世界许多国家已进入业务组网应用阶段,空基GPS气象学也取得了飞速发展。本文在介绍了空基GPS掩星探测的发展历史和探测原理的基础上,重点分析了国际上GPS-LEO掩星探测数据处理和应用领域的最新研究和进展,对我国的GPS-LEO掩星探测研究进行了回顾和总结,最后对GPS-LEO掩星探测未来的发展进行了展望。     

Nonlinear coherent four‐wave interaction in space plasma

According to a widespread point of view, intensive electrostatic structures in the E‐region of the auroral ionosphere can be a consequence of the excitation of the modified two‐stream or Farley‐Buneman (FB) plasma turbulence. But in spite of the successes of the theoretical and experimental research of the auroral radar scattering, it is impossible to explain the existence of auroral echoes with large aspect angles (> 2 deg.), the wave propagation perpendicular to the electron drift velocity and wave scales less than 1 m. In this paper the coherent nonlinear interactions of three and four electrostatic FB‐waves are considered analytically and numerically. The evolution of the nonlinear waves is described by a system of magnetohydrodynamic equations. 1) It is shown that the interaction of three and four coherent waves is the main physical mechanism which leads to the saturation of the FB‐instability. 2) If no dissipative and dispersive effects occur, an explosive instability may be excited. 3) The main result of the interaction of coherent waves is the generation of nonlinear waves and nonlinear structures when the waves are damped linearly and propagate perpendicular to the electron drift velocity. This region corresponds to large aspect angles of the small‐scale waves. 4) Further, the wave interaction causes a nonlinear stabilization of the growth of the high‐frequency waves and a formation of local density structures of the charged particles. The results of the numerical models allow to analyse the possibility of scenarios of the two‐stream plasma instability in the collisional auroral E‐region.     

Current-driven plasma turbulence in a magnetic flux tube

The behaviour of a multi-component anisotropic plasma in a magnetic flux tube is studied in the presence of current-driven electrostatic ion-cyclotron turbulence. The plasma transport is considered in both parallel and perpendicular directions with respect to the given tube. As one of the sources of the parallel electric field, the anomalous resistivityof the plasma caused by the turbulence is taken into account. The acceleration and heating processes of the plasma are simulated numerically. It is found that at the upper boundary of the nightside auroral ionosphere, the resonant wave-particle interactions are most effective in the case of upward field-aligned currents with densities of a few 10^—6 A/m². The occurring anomalous resistivity maycause differences of the electric potential along the magnetic field lines of some kV. Further it is shown that the thickness of the magnetic flux tube and the intensity of the convection strongly influence the turbulent plasma heating.