Characteristics of Seismic Wave Propagation in the Binchuan Region of Yunnan Using a Dense Seismic Array and Large Volume Airgun Shots

The Binchuan region of Yunnan is a structurally complex region with mountains, basins, and active faults. In this situation,seismic wave propagation exhibits complex characteristics due to strong heterogeneity of underground media instead of following the great-circle path. In order to obtain a high-resolution shallow crustal structure, a dense seismic array was deployed during March 21 to May 30, 2017 in this area. To better understand the complexities of seismic wave propagation in this region, we perform array-based frequency-domain beamforming analysis and single-station based polarization analysis to investigate the characteristics of seismic wave propagation, using airgun-generated P-wave signals recorded by dense array stations in this experiment. The results from these two methods both reveal similar but complex characteristics of seismic wave propagation in the Binchuan basin. The azimuth anomalies off the great-circle path are quite large with values up to 30°, which is caused by strong structural heterogeneity in the very shallow crust. Our research provide a better understanding of the complex geologic structures in this area and provide guidance for detecting concealed faults and distribution of velocity anomalies.     

新疆天文台26米望远镜L波段接收机线-圆偏振的转换

新疆天文台南山基地26 m射电望远镜L波段接收机使用线偏振馈源接收电磁波信号用于脉冲星观测。分子谱线观测和VLBI国际联测需要圆偏振信号,因此希望接收机能够观测圆偏振信号。论述了将线偏振电磁波转换为圆偏振电磁波的方案,研究了90 °电桥在偏振转换中的作用,介绍了偏振转换的调试方法。在圆偏振模块中使用90 °电桥完成线偏振信号到圆偏振信号的转换,两路圆偏振信号的隔离度达到使用要求,满足圆偏振观测的需求。这种线偏振信号到圆偏振信号的转换方式不影响接收机的系统温度。     

An operator perturbation method of polarized line transfer V. Diagnosis of solar weak magnetic fields

We present an application of the PALI (Polarized Approximate Lambda Iteration) method to the resonance scattering in spectral lines formed in the presence of weak magnetic fields. The method is based on an operator perturbation approach, and can efficiently give solutions for oriented vector magnetic fields in the solar atmosphere.     

改革开放以来广东省空间极化研究

改革开放２０年来广东省的空间结构演化表明：传统的核心－边缘模式已发生了很大的变化,区域出现多极化且次级核心区形成。广州华南中心城市的地位已经被香港所取代,韶关、湛江、汕头、潮阳等老中心城市地位不断下降,深圳、珠海、东莞、中山、顺德、南海和番禺等新兴城市正发展成为新区域增长中心。珠江三角洲经济发展开始向外围地区扩展,出现了反极化的趋势。全省空间差异扩大,形成了多层次的空间极化格局。     

地球内部各圈层介质的地球各向异性与地球动力学

地球内部各圈层的结构和构造在本质上是不均匀的各向异性的,各向异性的研究不论是对深化地球本体的认识,还是在资源、能源、灾害和环境以及全球变化的研究中均具有重要作用。本文基于这一科学问题的本质性和重要性着重讨论了以下５个问题：１）各向异性介质中地震波场效应与判据;２）复杂介质地震各向异性－Ｓ波分裂的成因分析;３）当今Ｓ波分裂监测技术的进展与探索;４）地震各向异性在不同科学问题研究中的效能;５）地震各向     

Application of fluorescence spectroscopic techniques and probes to the detection of biopolymer degradation in natural environments

The activities and substrate specificities of extracellular enzymes in natural systems are not well understood, despite their critical role in microbial remineralization of organic carbon. These enzymes initiate organic carbon degradation by selectively hydrolyzing high molecular weight substrates to lower molecular weight products which can be transported into cells. A set of single- and dual-labeled fluorescent polysaccharides was synthesized and characterized to explore a variety of approaches for measuring enzymatic hydrolysis of biopolymers via photophysical techniques, focusing particularly on rapid and robust optical techniques which are amenable to field measurements in remote locales. A shotgun-labeling approach yielded dual-labeled probes that exhibited substantial donor fluorophore quenching. The photophysical response of these probes to hydrolysis via purified enzymes was investigated in the lab, and fluorescence polarization proved to be a rapid and reliable technique for monitoring probe hydrolysis. Initial field results were also obtained from hydrolysis experiments in sediment porewaters. Because polarization measurements are rapid and simple, this approach could be used to follow the extracellular enzymatic hydrolysis of a wide range of biopolymers which fuel microbial metabolism.     

ADS辅助实现线极化到圆极化的转换

给出C波段双圆极化低噪声接收机中圆极化输出的实现方案,研究了利用90°电桥进行线- 圆极化转换时两个线极化通道增益及相位的平衡度对圆极化隔离的影响。分析了如何通过调节一对同轴电缆的长度差来补偿相位不平衡,并借助ADS软件计算了该长度差,实现了线-圆极化转换,取得接收机两个圆极化之间的隔离度好于20dB的效果。     

The solution of the vector radiative transfer equation using the discrete ordinates technique: Selected applications

The paper is devoted to the presentation of a newly developed radiative transfer code SCIAPOL_1.0 for a plane-parallel turbid slab illuminated by the monodirectional wide beam. The SCIAPOL_1.0 is based on the discrete-ordinates solution of the vector radiative transfer equation.The code is applied to a number of problems, including studies of the applicability of the scalar approximation for the calculation of light reflectance from aerosols, clouds, and molecular atmospheres. We also study the accuracy of the single scattering approximation as applied to the calculation of light reflection from molecular and cloudy atmospheres and propose new approximations for the calculation of the reflection function and the degree of light polarization under unpolarized light illumination conditions.     

椭球雨滴群旋转轴取向对双线偏振多普勒雷达参量影响的计算分析

以椭球粒子的电磁波散射理论为基础, 主要研究椭球雨滴群旋转轴在空间的取向特征, 建立粒子旋转轴空间取向与风场、 雷达天线仰角间的关系。在考虑粒子传输效应的情况下, 分析了旋转轴取向对双线偏振雷达探测参数ZDR和LDR的影响, 为提高双线偏振多普勒天气雷达观测资料的精度提供了理论依据。     

The Class 0 source Barnard 1c

We present our most recent results from an ongoing study of the Class 0 source Barnard 1c in Perseus. This source is of particular interest because it exhibits evidence of strong alignment of grains all the way to the core’s centre, which is contrary to all other low-mass protostellar cores observed to date. Our goal is to clarify the source of poor alignment in other sources by identifying the source of strong alignment in B1c. A central cavity has been identified in N₂H⁺ emission; its anticorrelation with C¹⁸O emission suggests that heating in the centre has released CO from grain mantles, in turn destroying N₂H⁺. We present sensitivity-limited, high spatial resolution polarimetry data from the SubMillimeter Array and discuss the potential implications of these data.