SIGNIFICANCE AND CHARACTERISTICS OF OPHIOLITE SUITE IN LAJI SHAN, SOUTHERN QILIAN MOUNTAINS, QINGHAI PROVINCE,CHINA

SIGNIFICANCE AND CHARACTERISTICS OF OPHIOLITE SUITE IN LAJI SHAN, SOUTHERN QILIAN MOUNTAINS, QINGHAI PROVINCE,CHINAthedoctoralprogramofhighereducation (970 49119)     

Introduction to Large High Altitude Air Shower Observatory (LHAASO)

Since the century discovery of cosmic ray, the origin of cosmic ray is always a mystery. The study on the origin of high-energy cosmic ray is in an interdiscipline between the very high-energy (VHE) gamma-ray astronomy and the cosmic ray physics. The Large High Altitude Air Shower Observatory (LHAASO) is a unique and new generation cosmic-ray station with the advantages of high altitude, all-weather, and large-scale. It takes the function of hybrid technology to detect cosmic rays and to upgrade greatly the resolving power between gamma rays and cosmic rays. The LHAASO is expected to make the full-sky survey to find new gamma-ray sources, to obtain the highest sensitivity of gamma-ray detection at the high energy band of > 30 TeV, and to make the very high precision measurement on the component energy spectra of cosmic rays in a broad energy range of 5 orders of magnitude, in order to provide the evidence for revealing the mystery of the origin of cosmic ray. This paper describes the detector structure, performance superiority and scientific motivation of the LHAASO.     

Research on Receiver Anti-RFI of Delingha 13.7 m Telescope

In astronomical observations, the radio frequency interference (RFI) will cause pseudo spectra and reduce the reliability and validity of observational data. The RFI mitigation, which includes many technical innovations of devices and the method studies of data processing, aims at reducing the influence of RFI on the radio astronomical observation. Various efforts were made to improve the anti-RFI capability of the multi-beam receiver (Superconducting Spectroscopic Array Receiver, SSAR) of the Delingha 13.7 m telescope. The interference transmission path was analyzed. The concepts of the device RFI direct coupling coefficient and the device RFI system coupling coefficient were proposed. The proportions of interference introduced in the receiver system by the different devices were quantified, and the interference-susceptible devices in the system were located. After the anti-RFI treatment of the interference-susceptible devices, the anti-RFI capability of the receiver system is improved by 30 dB in average, and the astronomical observation efficiency of the telescope is increased by more than 10%.     

Studying Solar Eruptions from Reconstructed Coronal Magnetic Field

The Sun is the celestial body in the sky with the closest relationship with the Earth. The violent eruptive activities happening on the Sun can greatly impact the human living environment and lead to disastrous consequences. It is well accepted that solar eruptions including the solar flare, prominence eruption and coronal mass ejection are the different manifestations of a single physical process powered by the magnetic free energy gradually stored in the corona prior to eruptions. Therefore, mapping the three-dimensional structure of coronal magnetic field is a prerequisite to understand the initiation mechanism of solar eruptions. Due to the technological and methodological difficulties, routine observations of the coronal magnetic field are still unavailable. Therefore, a number of methods have been developed to reconstruct the coronal magnetic field. This paper mainly reviews the applications of various reconstruction methods to the studies of the solar eruptions in the recent ten years.     

Structural Evolvement of Heating Treatment of Mg/Al-LDH and Preparation of Mineral Mesoporous Materials

Although hydrotalcite, or layered double hydroxides (LDHs), is not a common mineral, it is an important material that can be easily synthesized in laboratory. In this study, structural evolvement and BET surface area changes of heat treated Mg/Al-LDH is evaluated by XRD, TEM and N2-BET analyses. The results indicate that the magnesium-aluminum LDH with carbonate as interlayer anion, periclase-like oxides was formed at temperatures of 400-800℃. Meanwhile, 2-3 nanometer mesoporous were formed during decomposition of LDH. However, the heat treated samples still preserve the morphology of the original LDH plates. Periclase-like formed from LDH heat treatment may re-hydrolyze and recover the structure of LDH. However, crystallinity of the recovered LDH is lower than that of the original LDH. This heat treatment will result in formation of (Mg, Al)-oxide nano-crystals and nanopores among the nano-crystals. When heating temperature exceeds 1000, the periclase-like (Mg, Al)-oxide is transformed into a composite with periclase (MgO) and spinel phases. The periclase can be re-hydrolyzed and dissolved in HCl solution. After acid treatment, the sample with a high surface area is composed of spinel nano-crystals and nanopores among them. Our results will provide a new and economic way to synthesize mesoporous materials through pathways of phase transformation of precursor materials with different composition.     

川滇地区应变率场分布及其变化特征研究

基于GPS多期复测资料, 利用最小二乘配置方法计算川滇地区应变参数, 分析该区域应变率场分布及其变化特征并探讨其分布与强震关系。 研究结果表明: ① 各时段应变率场空间分布的明显变化应属于大于GPS资料误差的真实地壳构造形变信息; ② 最大剪应变率及第一、 第二剪应变率的结果反映了走滑断裂对区域变形的显著控制; ③ 主应变率, 东西、 南北向应变率场动态结果反映的汶川地震孕震的空间尺度较大; ④ 在本区大致反映北东向与北西向剪切变形的第一剪应变率、 东西向应变率、 南北向应变率及最大剪应变率与6级以上地震对应较好。     

冀东北地区中低温对流型地热系统的氟指示意义研究

为查明冀东北地区中低温对流型地热系统中氟的富集过程,通过对地热流体水化学特征和同位素数据的分析,研究地热流体中氟的分布特征、富集规律、水化学过程及影响因素。结果表明:研究区地热流体F^-含量为1.36~23.83 mg/L,呈现北高南低的趋势;在HCO3^-—Na^+和SO4^2-·HCO3^-—Na^+等Na型水中富集程度高于HCO3^-—Ca^2+和HCO3^-—Ca^2+·Mg^2+等Ca型水;碱性环境、温度和循环深度是影响氟离子富集的主要因素;水岩作用、含氟矿物溶解及阳离子交换作用,是控制高氟地热水水化学特征的主要地球化学过程。氟浓度异常可为寻找地热资源提供基础参考线索,为地热资源的科学合理利用提供科学依据。     

西藏地区重磁场特征及藏东构造格局新认识

根据新编制的1∶100万西藏地区重磁图发现,在西藏东部雁石坪—昌都地区存在一组北西向构造,它与西藏中西部发育的近东西向构造呈相交而不是相接关系,这与地质上通常认为的西藏地区主体呈北西—东西—北西西向的平卧"S"型构造格局观点相异,从而对西藏地区东部的地质构造格局有了新的认识。文中清晰地展示了这组北西向构造及近东西向构造的重磁场面貌,并推测认为这组北西向构造可能是从祁连山—东昆仑山北西向构造中沿东昆仑断裂分裂出来的,而先前认为的北西向构造与近东西向构造相接的观点反映的应是侏罗纪之后受印度地块向北推挤,上覆浅层构造特征,这个新发现对认识西藏地区地质构造格局具有重要意义。     

MT—1型煤岩层通讯机的性能设计及通讯距离

借助均匀导电全空间中垂直偶极产生的电场表达式,导出通讯性能参数与通讯距离的关系式,再依据使用要求(如额定穿透距离、轻便、本安防爆等),以关系式为基础选定和估算出MT-1的各项技术指标。对实际的层状地层,当电磁波顺(煤、岩)层传播时,由于波导效应,通讯距离会比设计值大;当垂直岩层通讯时,采用能延长的水平偶极距收发和低阻发射抽头增强发射电流可增加通讯距离。这一点在工业性试验中得到了证实。     

四川仪陇—平昌地区长兴组−飞仙关组层序地层及沉积演化

四川仪陇—平昌地区,特别是环开江−梁平海槽区域的长兴组—飞仙关组蕴藏着大量油气资源,但其三级层序划分方案有待统一。基于最新的钻井岩心、测井、野外露头资料综合分析,识别出岩性岩相突变界面及局部暴露不整合界面2种Ⅱ型层序界面,将仪陇—平昌地区的长兴组−飞仙关组划分为4个三级层序,建立了层序地层格架。该区目的层主要发育典型的镶边台地沉积体系,至晚期海槽消失,发育陆表海型台地体系开阔台地及蒸发台地。长兴组沉积期,开江−梁平海槽范围逐渐扩大,高位域是生物礁发育的有利阶段,由于SQ2晚期海平面急速下降,其生物礁规模较SQ1时期有所减小;飞仙关组沉积早期海平面快速上升,鲕粒滩难以形成,随后进入整体海退阶段,至SQ3高位域时期,鲕粒滩连片发育。层序划分方案与礁、滩储层发育特征匹配,能够应用于下一步油气勘探。