Isolation and biological characteristics of aerobic marine magnetotactic bacterium YSC-1

1 INTRODUCTION Magnetotactic bacteria are able to respond and orient along the direction of terrestrial or artificial magnetic field, a behavior referred to as magneto- taxis. In the majority of magnetotactic bacteria, the magnetosomes are 25–120 nm in d…     

Rupture process of the 2015 Pishan earthquake from joint inversion of InSAR,teleseismic data and GPS

An earthquake of Mw6.4 occurred in Pishan County in Xinjiang Province, northwestern Tibetan Plateau, on July 3,2015. The epicenter was located on an active blind thrust system located at the northern margin of the Western Kunlun Mountain Orogenic Belt southwest of the Tarim Basin. We constructed a shovel-shaped fault model based on the layered-crust model with reference to the seismic reflection profile, and obtained the rupture process of the earthquake from the joint inversion of Interferometric Synthetic Aperture Radar(InSAR) measurements, far-field waveform data, and Global Positioning System(GPS) data. The results show that the seismic fault dips southward with a strike of 109°, and the rupture direction was essentially northward. The fault plane rupture distribution is concentrated, with a maximum recorded slip of 73 cm. The main features of the fault are as follows: low inclination angle(25°–10°), thrust slip at a depth of 9–13 km, rupture propagation time of about 12 s, no significant slip in soft or hard sedimentary layers at 0–4 km depth and propagation from the initial rupture point to the surrounding area with no obvious directionality. The InSAR time-series analysis method is used to determine the deformation rate in the source region within 2 years after the earthquake, and the maximum value is ~17 mm yr-1 in the radar line-of-sight direction. Obvious post-earthquake deformation is evident in the hanging wall, with a similar trend to the coseismic displacement field. These results suggest that the Pishan earthquake has not completely released the accumulated energy of the region, given that the multilayer fold structure above the blind fault is still in a process of slow uplift since the earthquake. Post-earthquake adjustment models and aftershock risk analysis require further study using more independent data.     

建平地区三座庙序列侵入岩侵位机制讨论

通过野外对三座庙序列侵入岩的岩体平面与剖面形态、岩体的内部构造、岩石与围岩的构造型式、接触带的度形特征等宏观地质特征的研究,推测岩体侵入位机制为强力挤入方式定位,即气球膨张式。笔者运用岩石的有限应变测量原理和方法,结合岩组分析及流变学、现代变形理论,对三座庙序列的侵入岩岩石做了有限应变测量和岩组分析工作,所得定量资料为确定岩体的浸位机制提供了理论依据。三种岩石有限应变测量,即:算术平均法、长短轴法、Rf/φ曲线法的富林指数k值均在0相似文献   

渤海、黄海、东海海面热量平衡的平均状况——Ⅰ.资料处理和计算方法

渤、黄、东海海面热量平衡状况对该海域海洋水文和中国气候有着重要的影响。我们对该海域热量平衡各分量的年平均和年变化进行了计算,并分别就资料处理和计算方法、年平均状况、年变化特征等几个方面进行了分析。本文作为该项研究的第一部分,讨论了所用的资料和计算公式,提出了在稳定温度层结条件下的交换系数的校正方法。     

熊耳山—外方山区爆破角砾岩型金矿床的特征和有关找矿问题

熊耳山—外方山爆破角砾岩型祁雨沟金矿床和店访全矿床产于熊耳裂陷。由于控矿构造部位、地质营力作用和成矿流体的性质不同,分属祁雨沟式、店坊式,两者具不同的找矿标志。其中,祁雨为式具有较为重要的经济意义。在寻找分布在太华群一能耳群不整合面拆离断层带的祁雨沟式全矿床的同时,要注意寻找其它类型金矿,尤其要注意开发砂金矿,有利于减少污染,保护环境。     

长白山天池火山区长白-敦化剖面结晶基底的探测和研究

时间项分析法中,应用广义最小二乘法进行反演,对长白山天池火山区岩浆系统的长白—敦化(L1)剖面的Pg波到时进行了计算处理,得到了Pg波时间项及基底速度值;取上部地壳的介质平均速度为4．5km/s,经反演求得了各点的深度值,给出了长白山天池火山区结晶基底的厚度分布。结晶基底厚度一般在2．0km左右,而在长白山天池下方结晶基底最厚处接近4．0km;在万宝和敦化附近各有一不太明显的凹陷,其原因可能与在这两个位置处有几条断裂穿过有关。     

普弄巴金矿床黄铁矿的标型特征

笔者对本地区金矿床中黄铁矿的晶体结构形态、物理性质、微量元素及同位素进行了研究，结果表明：黄铁矿晶形呈五角十二面体，八面体－五角十二面体、立方体－五角十二面体聚晶富Ａｕ；黄铁矿的晶胞参数（ａ）、热电系数（α）与砷、金关系密切，基本上成正相关关系；黄铁矿质变热电系数的测定表明本区金矿床为中低温矿床；本区金矿床中的黄铁矿多数为空穴型，据其空间分布特征，认为本区金矿床深部可能有一定勘探远景；同位素研究表     

Evidence for Tibetan Plateau Uplift in Qaidam Basin before Eocene-Oligocene Boundary and Its Climatic Implications

Geometry analysis of the Hongsanhan (红三旱) Section in the northwestern Qaidam basin illustrates the typical growth strata in the Xiaganchaigou (下干柴沟) Formation. The age and sedimentation rates of the Xiaganchaigou and the Shangganchaigou (上干柴沟) formations were determined by the high-resolution magnetostratigraphy. This result shows that the growth strata began to form at ca. 38.0 Ma and increased sedimentation rates occurred at ca. 37.0 Ma. The uplift of the Tibetan plateau before the Eocene-Oligocene boundary is confirmed, which enables us to better understand the relationship between climatic changes and the tectonic uplift. This uplift event could have resuited in the regional drying by blocking the moisture and contributed to the Eocene-Oligocene boundary global cooling event due to the declining atmospheric CO2 concentrations by increased weathering of the mountains.     

青藏高原东南缘多尺度重力场变化特征及孕震机理分析

利用川西地区2017—2021年多期地面重力观测和地磁观测资料,对马尔康M_S6.0地震进行分析,并使用重磁场年变归一化融合分析结果对地震的发震位置进行分析,获得了融合分析结果和马尔康地震要素之间的相关关系。结果表明：区域重力场异常变化与川西地区断裂带在空间上关系密切,马尔康震中地区重力场变化较为微弱,变化量等值线始终在零值线左右,但在周边地区变化剧烈;岩石圈磁场年变化结果显示,震前岩石圈磁场水平矢量从区域整体弱变,到震中持续弱变和外围整体趋同后反向弱变,弱变量级较小且方向散乱;融合归一化震前一年期重磁场年变化数据,根据核密度曲线的重叠范围和峰值差较小的条件,可以判定出强震发震的区间范围（30°N～33°N,101°E～104°E）,2022年6月芦山M_S6.1和马尔康M_S6.0地震就发生在该区间范围内。进一步将川西地区按1°×1°的格网划分后,马尔康地区重磁变化核密度曲线峰值差逐年减小,并在发震前重力变化和地磁变化峰值差达到最小。马尔康地区重力场和岩石圈磁场的磁化率变化在孕震过程中逐年趋于一致,证明了区域内存在物质和能量的交换和动力作用,引起了活动断层物质变迁和构造变形,在地表产生了相应的重力变化和岩石圈内磁场变化。重磁场的年变融合分析对强震发震位置的判定具有一定的指导意义。