基于构造应力场识别震源机制解节面中发震断层面——以盈江地区为例

为了识别震源机制解节面中的实际发震断层面,本研究在反演震源处应力场的基础上,进一步计算震源机制解两个节面的不稳定系数,将其中最不稳定的节面视为实际发震断层面.本研究将上述方法应用于地震资料丰富且中强震发震构造研究较为深入的云南盈江地区,获得以下结论: (1) 2008年3月21日和2011年3月10日地震发震断层为震源机制解中NEE向节面,对应震中附近的大盈江断裂; 2008年8月21日地震的发震断层为震源机制解中NS向节面,对应震中附近近NS向苏典断裂; 2014年5月23日地震断层面识别结果为NEE向节面,其发震断层可能为昔马—盘龙山断裂; 2014年5月30日地震的发震断层为震源机制解中NS向节面,其发震断层可能是与苏典断裂平行的断裂.(2)盈江地区总体断层面识别结果显示盈江地区发震断层走向优势分布为近NS向和NEE向,呈现出共轭断层,研究区最大主压应力方向为NNE向; 断层走向和最大主压应力轴走向关系符合安德森断层理论.(3)本研究表明基于应力场识别震源机制解节面中发震断层面方法物理意义明确,实际应用结果合理可靠.

     

Detection of a high-confidence quasi-periodic oscillation in radio light curve of the high redshift FSRQ PKS J0805–0111

In this work,we have searched for quasi-periodic oscillations(QPOs)in the 15 GHz light curve of the FSRQ PKS J0805-0111 monitored by the Owens Valley Radio Observatory(OVRO)40 m telescope during the period from 2008 January 9 to 2019 May 9,using the weighted wavelet Z-transform(WWZ)and the Lomb-Scargle Periodogram(LSP)techniques.This is the first time to search for a periodic radio signal in the FSRQ PKS J0805-0111 by these two methods.Both methods consistently reveal a repeating signal with a periodicity of 3.38±0.8 yr(>99.7%confidence level).In order to determine the significance of the periods,the false alarm probability method was applied,and a large number of Monte Carlo simulations were performed.As possible explanations,we discuss a number of scenarios including the thermal instability of thin disks scenario,the spiral jet scenario and the binary supermassive black hole scenario.We expect that the binary black hole scenario,where the QPO is caused by the precession of binary black holes,is the most likely explanation.FSRQ PKS J0805-0111 thus could be a good binary black hole candidate.In the binary black hole scenario,the distance between the primary black hole and the secondary black hole is about 1.71×10¹⁶ cm.     

融合先验物理信息的高精度智能可控源电磁反演算法

可控源电磁反演利用人工信号获取地下结构信息,为地质勘探和资源开发提供准确的数据支持。然而,传统电磁反演方法面临低分辨率的挑战,主要是由于简化处理和观测数据的限制,导致模型平滑、细节丢失,从而削弱了反演的准确性,影响了电磁勘探的效率。为了解决这一问题,本文提出将传统反演结果与响应数据同时作为深度网络的输入数据,为深度网络反演提供先验物理信息,并结合深度学习算法提升可控源电磁反演的计算效率。通过模型试验,对合成的电阻率模型分别进行了传统反演、智能反演以及融合先验物理信息的智能反演。结果表明,融合先验物理信息的智能反演能够更好地刻画异常体结构特征,有效提升反演效率,并且得到的电阻率参数更符合实际。最后,将该反演技术应用于金川铜镍矿床的可控源数据反演解释,取得了较为可靠的应用效果。     

滇黔桂“金三角”地区晚三叠世地层碎屑物源示踪

三叠系是滇黔桂分布最广泛的岩系,赋存卡林型金矿等各种低温矿产。在前人研究基础上,运用LA-ICP-MS分析技术,对滇黔桂"金三角"地区的碎屑锆石进行了U-Pb测年。结果显示,大部分锆石具岩浆环带,Th/U值大于0.4,锆石U-Pb年龄集中在308~396 Ma、440~680 Ma、727~930 Ma、1004~1266 Ma、1400~1880 Ma、2360~2724 Ma六个区段。通过对比研究区及周围地块的碎屑锆石年龄分布特征,结合研究区岩相古地理、古海流及古流向,综合分析认为,研究区物源以越北古陆为主,同时湘粤桂构造山系和云开地区也可能提供了部分物源。该物源印证了古特提斯洋在印支期逐渐闭合,华南陆块与印支地块沿松马缝合带发生碰撞。     

Otolith development in larval and juvenile Schizothorax davidi: ontogeny and growth increment characteristics

Laboratory-reared Schizothorax davidi larvae and juveniles were examined to assess the formation and characteristics of David’s schizothoracin otoliths.Otolith development was observed and their formation period was verifi ed by monitoring larvae and juveniles of knownage.The results revealed that lapilli and sagittae developed before hatching,and the first otolith increment was identified at 2 days post hatching in both.The shape of lapilli was relatively stable during development compared with that of sagittae;however,growth of four sagittae and lapilli areas was consistent,but the posterior area grew faster than the anterior area and the ventral surface grew faster than the dorsal surface.Similarly,the sum length of the radius of the anterior and posterior areas on sagittae and lapilli were linearly and binomially related to total fish length,respectively.Moreover,daily deposition rates were validated by monitoring knownage larvae and juveniles.The increase in lapilli width was 1.88±0.080 0μm at the ninth increment,which reached a maximum and the decreased gradually toward the otolith edge,whereas that of sagittae increased more slowly.These results illustrate the developmental biology of S.davidi,which will aid in population conservation and fish stock management.     

LSQRD及解的分辨分析

较详细地介绍了ＬＳＱＲＤ（Ｌｅａｓｔ Ｓｑｕａｒｅ ＱＲ Ｄｅｃｏｍｐｏｓｉｔｉｏｎ） 反演方法以及“检测版”分辨分析方法,并举实例检验其应用。对于大型稀疏方程组的求解,ＬＳＱＲＤ 是一种内存需求小、计算效率高和抗噪能力较强的算法。“检测版”试验表明,ＬＳＱＲＤ也可以对迭代解进行有效的可靠性估计,以指导对反演结果的利用。     

西部大地形变数据库设计与建设

介绍西部大地形变数据库的设计与建设.     

Micromorphological features of diagnostic horizons in several soils in southwest China: Implication for soil taxonomic classification

The comparative studies on micromorphological features in diagnostic horizons of Stagnic Anthrosols, Ustic Ferrosols and Ustic Vertosols in southwestern China were conducted to underpin the rationale for Chinese Soil Taxonomy. The following findings were explored: (1) Stagnic Anthrosols had the specific micromorphological features, e.g., the humic formation in anthrostagnic epipedon, the platy structures in plow subhorizon, the secondary formation of ferromanganese and the weakly optical-orientation clay do...     

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Sea surface temperature and salinity reconstruction based on stable isotopes and Mg/Ca of planktonic foraminifera in the western Pacific Warm Pool during the last 155 ka

Changes in sea surface temperature(SST), seawater oxygen isotope(δ 18 O sw), and local salinity proxy(δ 18 O sw-ss) in the past 155 ka were studied using a sediment core(MD06-3052) from the northern edge of the western Pacifi c Warm Pool(WPWP), within the fl ow path of the bifurcation of the North Equatorial Current. Our records reveal a lead-lag relationship between paired Mg/Ca-SST and δ 18 O during Termination II and the last interglacial period. Similarity in SST between our site and the Antarctic temperature proxy and in CO 2 profi le showed a close connection between the WPWP and the Antarctic. Values of δ 18 O sw exhibited very similar variations to those of mean ocean δ 18 O sw, owing to the past sea-level changes on glacial-interglacial timescale. Calculated values of δ 18 O sw-ss refl ect a more saline condition during high local summer insolation(SI) periods. Such correspondence between δ 18 O sw-ss and local SI in the WPWP may refl ect complex interaction between ENSO and monsoon, which was stimulated by changes in solar irradiance and their infl uence on the local hydrologic cycle. This then caused a striking reorganization of atmospheric circulation over the WPWP.