Analyzing the capability of a radio telescope in a bistatic space debris observation system

A bistatic space debris observation system using a radio telescope as the receiving part is introduced. The detection capability of the system at different working frequencies is analyzed based on real instruments. The detection range of targets with a fixed radar cross section and the detection ability of small space debris at a fixed range are discussed. The simulations of this particular observation system at different transmitting powers are also implemented and the detection capability is discussed. The simulated results approximately match the actual experiments. The analysis in this paper provides a theoretical basis for developing a space debris observation system that can be built in China.     

岩石圈内部第二深度空间金属矿产资源形成与集聚的深层动力学响应

中国的快速工业化发展和经济腾飞必须有大量金属矿产资源的支撑,在共享世界资源的同时,其根本出路在于立足本土．因此提出第二深度空间（500～2000 m）金属矿产资源的找矿勘探新理念．通过对国内外金属矿产资源地球物理勘探发展的概况分析和研究提出：①金属矿产资源的集聚和分布受控于地壳内部物质与能量的交换和其深层动力过程;②在地壳内部第二深度空间存在着丰富的矿产资源,包括大型和超大型矿床;③必须充分发挥高精度地球物理探测方法的效能,并进行综合技术集成．     

云南白水台钙华景区的水化学动态变化研究

本文采用水化学仪器自动记录、现场测定和取样室内分析等相结合的方法,对云南白水台钙华景区水的物理化学动态变化特征进行了综合研究,结果发现: 随着CaCO3 的沉积,水中的主要离子Ca2+ 和HCO-3 浓度、电导逐渐降低; p H值升高。我们对1号泉进行昼夜观测发现: 5月1号泉的水温呈周期性变化,周期约为28小时,而在9月水温保持恒定。对下游( 12号观测点)的动态观测发现水的p H值与水温呈反相关关系,在对中游( 6号观测点)的早、中、晚观测得到了同样的结果。最终我们得出结论: 1号泉水温变化可能受补给水源水温动态变化、降雨和地热影响;中下游pH值和电导率的变化与碳酸钙的沉积速率、碳酸平衡和藻类作用有关。      

层状饱和场地分布荷载的动力Green函数及应用

研究波在层状饱和场地中的传播,在理论和实际工程中均有十分重要的意义.采用Biot基本模型,利用层状饱和土的精确动力刚度矩阵,给出了层状饱和场地中分布荷载作用于与水平向有夹角的倾斜直线时的动力Green函数,解决了利用间接边界元法计算层状饱和场地中任意凹陷地形对地震波散射以及土一结构相互作用中的关键问题.     

张家口断裂发现第四纪晚期活动证据

作者等人在“河北省城市活断层探测与地震危险性评价（张家口项目）”2008年探测工作中对张家口断裂进行了地质调查,多处发现了清楚的第四纪晚期（晚更新世-全新世）断层活动剖面,获得了张家口断裂晚第四纪活动的可靠证据,为张家口市活断层探测打下了坚实基础。     

Application of support vector machine to synthetic earthquake prediction

This paper introduces the method of support vector machine (SVM) into the field of synthetic earthquake pre-diction, which is a non-linear and complex seismogenic system. As an example, we apply this method to predict the largest annual magnitude for the North China area (30°E-42°E, 108°N-125°N) and the capital region (38°E-41.5°E, 114°N-120°N) on the basis of seismicity parameters and observed precursory data. The corresponding prediction rates for the North China area and the capital region are 64.1% and ...     

丹东形变观测洞室改造

“十五”期间,为了新增水管仪、伸缩仪,丹东地震台对形变观测洞室进行了环境改造,新建了仪器基墩,解决了建造仪器基墩过程中遇到的施工难题,为水管仪和伸缩仪运行提供了良好的观测条件。文中介绍的方法对其他台站建造仪器基墩有一定借鉴意义。     

The mechanism for the impact of sea surface temperature anomaly on the ridgeline surface of Western Pacific

Based on the atmospheric circulation data provided by ECMWF and the sea surface temperature data by NOAA, we studied the mechanism for the impact of sea surface temperature anomaly on the ridgeline surface of western Pacific using an improved high truncated spectral model. Our results show that the wave-wave interaction and the wave-mean flow interactions are weaker in the inner dynamic process of atmospheric circulation, when atmospheric circulation is forced by the sea surface temperature of El Niño pattern. With the external thermal forcing changed from winter to summer pattern, the range of ridgeline surface of western Pacific moving northward is smaller, which causes the ridgeline surface of western Pacific on south of normal. On the contrary, the wave-wave interaction and the wave-mean flow interaction are stronger, when atmospheric circulation is forced by the sea surface temperature of La Niña pattern. With the external thermal forcing turning from winter to summer pattern, the ridgeline surface of western Pacific shifts northward about 19 latitude degrees, which conduces the ridgeline surface of western Pacific on north of normal. After moving to certain latitude, the ridgeline surface of western Pacific oscillates with the most obvious 30–60 d period and the 4°–7° amplitude. It is one of the important reasons for the interannual variation of ridgeline surface of Western Pacific that the atmospheric inner dynamical process forced out by different sea surface temperature anomaly pattern is different.     

某地红砂岩多轴受力状态蠕变松弛特性试验研究

与岩石单轴蠕变松弛试验研究相比,多轴的研究结果很少,这一现状的结果是岩石的三维蠕变松弛模型基本是其单轴模型的简单推广,缺乏试验资料的佐证。为了积累宝贵数据,推动岩石多轴蠕变松施模型的发展,利用广东某地的红砂岩开展了以下试验研究：(1) 不同围压下岩石的蠕变松弛特性;(2) 二向受力状态下岩石的蠕变松弛特性;(3) 多轴受力时,饱水和风干状态下岩石蠕变松弛特性的对比。总结、分析试验结果,获取了该种红砂岩多轴蠕变松弛特性的一些基本规律或现象,如：轴压相同时,侧压越高,蠕变量越小;当围压相同、时间相同时,应力 越高,则 的松弛量也越大。这些结果对于岩石力学的基础研究及现场施工设计均具有较大意义。     

均匀设计在岩土工程概率分析中的应用

基于神经网络的响应面蒙特卡罗方法,通过引入均匀设计来安排RBF神经网络的训练样本集,将均匀设计和RBF网络的优势有机地结合起来：一方面尽量减少训练样本点的数量;另一方面,训练样本点均匀地充满参数空间,有利于提高具有较强局部逼近能力的RBF网络的预测精度。应用该方法进行挡土墙结构抗滑移稳定性的概率分析,结果表明该方法与直接蒙特卡罗模拟的结果相当吻合,能够满足实际工程的精度要求。分析还表明,随机因素对挡土墙结构抗滑移稳定性的影响程度由大到小依次为基底摩擦系数、填土摩擦角、填土重度和填土对挡土墙墙背的摩擦角。