宇宙线μ子能谱及其应用

完成由两块大面积塑料闪烁体组成的粒子望远镜的研制,并测得合肥地区地面宇宙线μ子能谱.简要报道这台粒子望远镜的实际应用.     

行星际超低噪声三维能量粒子谱仪设计

太阳系能量粒子的起源和加速一直是空间物理学的重要前沿课题之一.在行星际空间中观测到的太阳系能量粒子主要分为两类：一类是持续存在的“太阳风能量粒子”,另一类是间歇性的“太阳能量粒子事件”.受限于以往行星际粒子探测器的灵敏度还不足够高,人类迄今仍未洞悉这些能量粒子起源和加速的物理过程与本质.本文设计了技术指标均为国际领先水平的行星际超低噪声三维能量粒子谱仪,采用双端望远镜结构（一端利用薄膜阻挡质子技术实现高灵敏电子探测,另一端利用磁场偏转电子技术实现高灵敏质子探测）,结合多层、多像素半导体探测器阵列和覆盖近4π立体角的大视场设计,实现对行星际空间中20～1 000 keV电子和25～12 000 keV质子的三维分布进行高时间分辨率、高角度分辨率和高能量分辨率探测,用以揭示太阳系能量粒子起源和加速的机理,满足我国行星际探测和即将开展的深空探测的迫切需求.     

太阳X-EUV成像望远镜

太阳X_EUV成像望远镜用来监测和预报影响空间天气变化的太阳活动,专门服务于空间天气预报研究. 望远镜工作在4～100?的X射线波段和195?极紫外谱段,视场角45′,角度分辨5″,提供全日面、高分辨的成像观测. 文中分析了太阳X、EUV波段的成像观测应用,介绍了X_EUV望远镜的基本设计,分析了望远镜对不同温度日冕等离子体的敏感性、对不同太阳活动现象的响应及反演日冕等离子体参数过滤片的组合利用. 太阳X_EUV成像望远镜集成了掠入射望远镜和正入射望远镜两套系统,扩展了单一X射线望远镜的成像功能,能够观测更多的太阳爆发先兆现象或者伴生现象,是目前国际上同类仪器中最新的太阳成像监测仪器.     

用中微子望远镜揭示地球

用中微子望远镜揭示地球许智莫纳斯特斯基地球物理学家为探查难以接近的地球内部而求助于天空。一个研究小组利用能够探测宇宙中微子的新天文仪器，希望把这些来自空间的虚无缥缈的粒子用作行星级ＣＡＴ扫描器以揭示地球内部结构。上周（１９９３年１２月上旬──译注）在...     

云南天文台望远镜基墩振动观测与分析

本文叙述了云南天文台1米望远镜基墩和太阳精细结构望远镜基墩振动的观测方法,分析了基墩振动位移和频率特征,计算了1米望远镜基墩的振动倾角和阻尼比,为今后设计望远镜基墩提供数据。     

基于粒子群优化算法的叠前角道集子波反演

本文探讨了粒子群优化(PSO)算法在叠前地震角道集子波反演中的应用.在基本最优PSO算法的基础上,提出了对粒子更新速度进行平滑滤波的改进最优粒子群算法.由于代表子波的粒子的维数较大,如果粒子的各维元素相互独立,将导致粒子速度更新紊乱,影响搜索速度.通过对粒子速度进行三点均值滤波,加强了单个粒子各维元素的相互联系,并防止了粒子速度逃逸,使粒子更快地向有利于最优解的位置收敛.该方法应用于叠前角道集子波的反演中,取得了较好的子波反演效果,证明了本文方法的有效性.     

“资源一号”卫星星内粒子探测器对扰动事件的观测

本文比较了在太阳平静和扰动时期“资源一号”卫星星内粒子探测器对卫星舱内高能粒子的观测结果，发现在平静时期观测结果很好地反映了辐射带高能粒子在该高度上的分布情况.在扰动时期，粒子探测器观测到高能粒子分布出现重大变化，本文进一步讨论了影响高能粒子在近地空间分布的可能因素.     

基于改进粒子群算法的地震标量波方程反演

针对标准粒子群优化(PSO)算法存在易出现早熟而陷入局部最优以及进化后期收敛速度慢等缺陷,通过考虑粒子所处位置间相互作用,提出了一种改进的并行粒子群优化算法.由于引入粒子位置间的相互影响,减少了粒子搜索过程盲目性,因此能有效提高算法的收敛速度.数值试验表明,这种改进的粒子群算法适用于二维标量波方程的速度反演,且算法具有...     

风云一号C星空间粒子成分探测器及SAA区粒子辐射实测分析

FY 1C星空间粒子成分探测器能够实现对质子能谱、电子积分通量及重离子成分的同时测量.在第23周太阳活动峰年期间,空间粒子成分探测器对860km高度的南大西洋负磁异常区高能粒子辐射进行了长达3年的连续探测.本文根据实测结果,得出了南大西洋负磁异常区粒子辐射特征,分析了太阳质子事件和地磁暴对南大西洋负磁异常区粒子辐射的影响.     

一种新的地震子波提取与层速度反演方法

粒子群优化算法是近十年发展起来的一种基于群智能的非线性全局最优化新方法.本文详细介绍了粒子群优化算法的基本原理,并将其应用到子波提取与层速度反演中.通过模拟数值算例,从不同角度研究了粒子群优化算法的可行性及其效率问题.试算结果表明,粒子群优化算法在不同分辨率、不同信噪比、不同相位子波合成的地震记录反演中效果明显.     

A Monte Carlo study of rainfall forecasting with a stochastic model

A procedure for short-term rainfall forecasting in real-time is developed and a study of the role of sampling on forecast ability is conducted. Ground level rainfall fields are forecasted using a stochastic space-time rainfall model in state-space form. Updating of the rainfall field in real-time is accomplished using a distributed parameter Kalman filter to optimally combine measurement information and forecast model estimates. The influence of sampling density on forecast accuracy is evaluated using a series of a simulated rainfall events generated with the same stochastic rainfall model. Sampling was conducted at five different network spatial densities. The results quantify the influence of sampling network density on real-time rainfall field forecasting. Statistical analyses of the rainfall field residuals illustrate improvement in one hour lead time forecasts at higher measurement densities.     

Earthquake Engineering and Engineering Vibration Aims And Scope

正This journal is established by the Institute of Engineering Mechanics(IEM),China Earthquake Administration,to promote scientific exchange between Chinese and foreign scientists and engineers so as to improve the theory and practice of earthquake hazards mitigation,preparedness,and recovery.To accomplish this purpose,the journal aims to attract a balanced number of papers between Chinese and     

Foreword

Destructive earthquakes have caused great damage in China and the United States and collapsing buildings havecaused many deaths and injuries. The field of earthquake engineering studies earthquake hazards, the occurrence ofearthquakes of various magnitudes, the nature of the ground shaking during an earthquake, the vibration of structuresduring earthquakes, the strengthening of existing structures and the design of new structures to be earthquake resistant,and finally, how to cope with earthquake damage and restore a city to normal functioning. Such efforts are in progressin both countries, but unfortunately, the language barrier interferes with the free flow of information between China andthe Untied States. It would be mutually beneficial if some means could be developed to promote the exchangeof information across the Pacific Ocean. This new journal has been established for this purpose and its success willbe an important step in promoting earthquake engineering in China and the United States.     

WORLD ASSOCIATION FOR SEDIMENTATION AND EROSION RESEARCH(WASER)

正President:Giampaolo Di Silvio,Italy Vice Presidents:Ulrich C.E.Zanke,Germany Zhao-yin Wang,China The World Association for Sedimentation and Erosion Research(WASER),inaugurated on Oct.19,2004,is an independent non-governmental,non-profit organization.The mission of WASER is to promote international co-operation on the study     

Enhancing remote sensing research on global change to improve our understanding on Earth system processes

正Global Change includes climate change and other environmental changes caused by the joint interaction among various layers of Earth. From the positive side, global change provides new opportunities to human and other living forms on Earth. In the meantime, it creates tremendous challenges and negative impact. At present, the negative impacts have reached all primary processes of the global ecosystem and every aspect of human society, especially causing degradation of the ecosystem. For instance, intensive deforestation causes decline of biodiversity; global warming causes sea level rise and increases     

Solute concentrations in the lower niger river and the source rock contribution

Water quality analyses for the Niger River for the 1980/81 hydrological year are presented. The samples were collected from the main river at Lokoja, and from two main tributaries, the Kaduna and the Benue Rivers. Different water types were distinguished by the concentrations of major ions. The type Ca > Na > Mg > K - HCO₃ > SO₄ > Cl was represented at all stations during at least part of the year. Chloride was found to dominate the sulphate ion in the Kaduna and Niger, while the Benue maintained a higher concentration of sulphate relative to chloride all year round. Distinct patterns of seasonal variation in the ion concentrations were observed, particularly for the samples collected at Lokoja. Low ion concentrations were prominent during periods of high discharge, while low flow periods coincided with high dissolved ion concentrations. The contribution of rainwater to the total dissolved solids in the river waters was assessed indirectly using rainwater chemistry data from the Gulf of Guinea. The estimated rainwater contribution to the Lower Niger amounts to 5.15 mg 1^?1. Geochemical weathering calculations involving reactions of the four major minerals of granitic rocks - anorthite, biotite, albite, and K-feldspar - with carbon dioxide and water, can account for the average water composition of the Lower Niger. The proportion of the ionic components was also related to the occurrence of the respective element in the minerals.