5个CSS源50cm VLBI观测数据的再处理

本文给出了全球VLBI网50cm数据成图再处理的部分结果.样本包括5个CSS射电源:3C43、3C138、3C186、3C216和3C237.为了便于比较,同时给出了二次成图处理后的图象.通过对这些源的形态描述,并且通过与其它波段高分辨率图的对照,核实了再处理图上各子源的位置,这些低频观测细节,对更好地了解CSS源的本质无疑是十分有益的。     

COMPOSITIONAL VARIATIONS IN MANGANESE NODULES COLLECTED FROM THE NORTH PENRHYN BASIN

Manganese nodules collected from the North Penrhyn Basin are characterized by low content of Mn and Fe, medium content of Ni and Cu , and medium Mn / Fe ratios . The average content of Ni plus Co is 1.11% , maximum 1.89% . Ni content slightly exceeds the Cu content in the nodules. Ni and Cu are strongly correlated with Mn , whereas Co is strongly correlated with Fe . Nodules containing Ni+Cu+Co near or in excess of 1% are rich in Mn and have a high Mn/Fe ratio. Those with highest content of Ni+Cu+Co are concentrated at or near the carbonate compensation depth . Nodules metal contents vary with latitude and have a reciprocal relationship with abundance. Contents of Mn, Ni, Cu and Ni+Cu+Co are high in nodules found at 2 - 6°S and vary decreasingly toward 1°N and 12°S , whereas Co content varies increasingly from 2°S towards 12°S. Nodule compositional variations with latitude are controlled by biological productivity, carbonate compensation depth , sedimentation rate, and bottom current.     

Seismic Response Analysis of Portal Water Injection Sheet Pile

1 Introduction The portal water injection sheet pile (PWISP) is a new type of space-retaining structure developed for the Shengli Oil Company. It was developed based on the combination of the practical needs of hydraulic projects and the technical principle of jet-drilling in the oil indus-try and has been successfully used for disaster prevention and hydraulic projects (Guo, 2002, 2005). It consists of the double-row parallel-prefabricated reinforced concrete sheet piles and the connectio…     

四颗南天脉冲星在1560 MHz上的偏振观测

本文给出88年6月和7月期间在澳大利亚Parkes进行的一次南天脉冲星偏振观测的部分有意义的结果。频率为1560MHz。采用了Jodrell Bank天文台新研制成的2×16×5MHz滤波系统,使这次观测具有很强的消色散能力和较高的灵敏度。这4颗南天脉冲星具有较强的线偏振,为首次获得的高频偏振资料。     

A Scheme for Objective Analysis of Wind Field Incorporating Multi-Weighting Functions in the Optimum Interpolation Method

A method of objective analysis scheme having three different weighting functions for different conditions of the wind flow has been developed for the Indian region, two of which are anisotropic and third one is isotropic. Basically Gandin’s Optimum Interpolation method is used. The “effective” distance between a grid point and observation point used for the anisotropic functions, has been applied to calculate weighting functions following Benjamin and Seaman (1985) and objective analyses were made at the 700 hPa level for three consecutive days from 6 July to 8 July 1979. The quantitative evaluation of the objectively analysed fields have been made by computing the R.M.S. errors. Ana-lyses obtained using multi-weighting functions (anisotropic) and those obtained using ordinary circular functions (isotropic-Gandin, 1963) have been compared. Also, the centres of the monsoon depressions obtained by this method have been compared with those of subjective analyses.     

通过神经网络加速实现大型黏弹性计算

认识重复地震周期活动的影响,其最大的挑战之一是大尺度的黏弹性地震周期模型的计算成本。对于计算密集型黏弹性代码,须在数以千计的时间和位置点上进行评估。因此,研究趋向于采用几个固定的流变结构和模型几何结构,考查所预测的大震后短时间(小于10年)内给定深度处不同时间的形变。训练一个深层神经网络来学习黏弹性解在任意时间、位置和大范围流变结构计算效率的表示,可快速且可靠地完成计算,并具有较高时空分辨率。结果表明,该机器学习方法可以将黏弹性计算速度提高50 000%以上。这种加速量级将使得在更大的模型参数范围内、在比以前更大的时空尺度上和数千个地震周期内,模拟几何结构复杂的断层成为可能。     

光学-近红外相机CASCAM的机械设计

光学近红外相机CASCAM(Chinese Academy of Sciences．Camera)采用光学CCD和近红外阵列HAWMH-1(HgCdTe Astronomical Wide Area Infrared Imaging)探测器，配备兴隆2．16m望远镜可同时进行光学、近红外成像和偏振观测。CASCAM的机械系统主要包括光学箱、真空箱以及致冷设计。其中光学箱是相机光学系统和探测器的载体，同时防止来自光学箱外部的红外热辐射；真空箱位于光学箱外部，它是整个系统的机械支撑，保证相机有良好的真空密封性能，并和真空泵、冷冻机一起构成了相机的致冷系统。     

CARAIB陆地碳循环模型研究进展及其应用

陆地生态系统碳循环是全球变化研究中的重要组成部分,多种模型已用于陆地生态系统碳循环的模拟。文中着重论述了陆地生物圈碳循环模型CARAIB的原理、方法及其应用和最新进展。CARAIB模型主要是基于叶面光合作用子模型、冠层子模型和木质呼吸作用3个子模型的耦合,应用大气环流模式气候数据模拟出生态系统碳存储量和生物群区分布。介绍了欧洲利用植物数字化地理配准数据库重新划分植物群组(BAGs)的方法,比较BAGs与传统的植物功能型(PFTs)划分在方法上的差异,根据植物群组应用CARAIB模型进行生物群区分布模拟,并提出利用CARAIB模型模拟我国陆地碳循环和生物群区分布的可行性,为研究中国植被对气候变化的响应模型和预测提供区域尺度的新方法。