三角剪切断层传播褶皱在祁连山北缘断裂中的应用:以黑河口断层为例

逆冲断层运动学过程研究可为造山作用和盆地演化提供重要的信息。位于青藏高原东北缘的祁连山北缘逆冲断裂（NFT）是一条主要的边界断裂,控制着祁连山晚新生代以来的隆升变形,但对于该断裂系统的运动学过程缺乏研究。甘肃张掖西南莺落峡附近,黑河口断层（祁连山北缘断裂的一部分）穿过红沙沟并导致其阶地面错断和褶皱变形。为了研究该区域褶皱变形特征和断层运动学过程,我们首先在红沙沟区域进行了详细的野外考察并对变形的地层和阶地面进行了测量,然后通过数值模拟方法来验证褶皱模型。红沙沟保存有9级河流阶地,利用差分GPS对阶地面的高程进行了测量,同时在野外测量了部分地层的产状。多处断层剖面表明该区域变形属于基底卷入的构造类型,另外变形的阶地面在近断层处表现出明显的褶皱形态。结合阶地面变形特征以及地层的变形,三角剪切断层传播褶皱模型被初步用于该区域构造变形的解释。模型模拟得到自T5、T6和T7形成以来断层滑动量分别是 44±7m、59±10m和 164±28m;结合T6年代得到自约9万年以来该断层的平均滑动速率为 0.68±0.19mm/a,垂直分量为 0.58±0.13mm/a。根据地层与阶地变形特征,并结合模型模拟结果,我们认为祁连山山前基底断层卷入的构造中,在断层出露地表之前,断层顶端存在一个分散式的三角形变形区,区域的应力状态控制着下伏地层和上覆地貌面的褶皱变形。     

Combined perturbation on near-earth satellite orbits

Using a semi-analytical method, we have obtained a first-order solution of the equations of motion of near-Earth satellites under the combined perturbing effect due to Earth's figure and air drag.     

On the hawking evaporation of Dirac particles in Kerr-Newman spacetime

We have obtained a solution of the Dirac equation near the horizon of a Kerr-Newman black hole and compared it with the solution of the Klein-Gordon equation. We first generalized the work of LIU Liao and XU Dian-yan for a quasi-extreme Kerr black hole to a quasi-extreme Kerr-Newman black hole, then further generalized to a general Kerr-Newman black hole, and thereby verified that the Dirac particles emitted by a general Kerr-Newman black hole do have a black-body energy spectrum.     

Distribution of suspended particulate matter in the northern Bohai Bay in summer and its relation with thermocline

Field observations of suspended particulate matter (SPM) in the Bohai Bay, China have not been widely reported. The aim of this paper is to describe the horizontal and vertical distribution of mass and volume concentrations of SPM, respectively, based on observed data at 312 stations in the northern Bohai Bay during summer of 2006. A numerical model ECOMSED coupled with a sediment transport module was also established to further discuss the mechanism of the thermocline effect on the vertical distribution of SPM. The mass concentrations of SPM exhibited high inshore values and low offshore values in the horizontal distribution; while in the vertical direction, characteristics of the volume concentration of SPM can be divided into two types: one with a sharp peak at depth of 10–15 m and another without. The peak value at the depth of the thermocline was resulted from concentrated phytoplankton. A numerical experiment further displayed that the thermocline can also prevent particles from being resuspended upward.     

Using a New Sky Brightness Monitor to Observe the Annular Solar Eclipse on 15 January 2010

For the future development of Chinese Giant Solar Telescope (CGST) in Western China, a new sky brightness monitor (SBM) has been produced for the site survey for CGST. To critically examine the performance and sensitivity of SBM, we used it in the observation of the annular solar eclipse in Dali City, Yunnan, on 15 January 2010. The observation met good weather conditions with an almost clear sky during the eclipse. The SBM measurement translates into the solar illuminance changes at a level of 2.4×10^?4 I?s^?1 during the eclipse. The time of the minimal sky brightness in the field of view (FOV) is found consistent with the time of maximum eclipse. Two local sky regions in the FOV are chosen to make a time series of the calibrated skylight profiles. The evolution of the sky brightness thus calibrated also shows good consistency with the eclipse, particularly between the second and the third contacts. The minimal sky brightness in each local sky region took place within half a minute from the corresponding predicted contact time. Such small time delays were mainly caused by occasional cirri. The minimal sky brightness measured during the eclipse is a few millionths of I _?? with standard deviation of 0.11 millionths of I _??. The observation supports that the single-scattering process (optically thin conditions) is the main contributor to the atmospheric scattering. We have demonstrated that many important aerosol optical parameters can be deduced from our data. We conclude that the new SBM is a sensitive sky photometer that can be used for our CGST and coronagraph site surveys.     

Correction of the temperature effect in calibration of a solar radio telescope

This work analyzes the annual fluctuation of the observation data of the Mingantu Solar radio Telescope(MST) in S, C and X bands. It is found that the data vary with local air temperature as the logarithmic attenuation of equipment increases with temperature and frequency. A simplified and effective calibration method is proposed, which is used to calibrate the MST data in 2018–2020, while the correction coefficients are calculated from data in 2018–2019. For S, C and X bands, the root mean square errors of one polarization are 2.7, 5.7 and 20 sfu, and the relative errors are 4%, 6% and 8% respectively. The calibration of MUSER and SBRS spectra is also performed. The relative errors of MUSER at 1700 MHz,SBRS at 2800 MHz, 3050 MHz and 3350 MHz are 8%, 8%, 11% and 10% respectively. We found that several factors may affect the calibration accuracy, especially at X-band. The method is expected to work for other radio telescopes with similar design.     

Modulational behavior of electromagnetic waves in ultra-relativistic electron-positron plasmas

The dynamical properties of electromagnetic (EM) waves in ultra-relativistic electron-positron (EP) plasmas are analytically investigated on the basis of the nonlinear governing equations obtained from a kinetic way. It is shown that the EM wave envelope will collapse and be trapped into a localized region for the modulation interaction with low frequency density variation induced by ponderomotive force. The correlation between the localized strong wave field and the pulsar radio emission is discussed.     

苡茨河泥石流地质灾害及防治

据统计,1992~2013年苡茨河曾多次发生泥石流地质灾害,并造成村民生命财产巨大损失。2013年7月24日再次爆发泥石流,破坏农田71280m2(108亩)。因此在对苡茨河泥石流形成条件、活动特征分析基础上,分析其泥石流的形成机制及其造成巨大危害的原因,预测其发展趋势,在已有治理措施的基础上,提出两种防治对策进行对比,得出一个较为合理的防治方案。     

渤海湾北岸TZ02孔晚新生代沉积环境演化过程

渤海湾北岸晚新生代沉积环境和沉积体系不仅是区域水文地质、工程地质的基础,也为古近纪沉积模式提供“将今论古”的依据。本文依据沉积物色度和粒度,以及沉积物岩性、结构和构造等,将渤海湾北岸TZ02孔划分了6个沉积组合、4个沉积阶段：1）2.10~3.22Ma,沉积组合Ⅰ和Ⅱ,湖盆填充期,发育湖相-泛滥平原相或湖相-曲流河相,该时期处于构造稳定期,干冷气候时期发育河流相、泛滥平原相,湿润气候时期发育湖泊相。2）1.33~2.10Ma,沉积组合Ⅲ,湖盆开始发育期,主要为浅湖相,仅有少量砂体,下部多有机质,上部多钙质淀积结核,指示了盆山之间的构造分异后,湖泊初始发育的特征。3）0.62~1.33Ma,沉积组合Ⅳ,湖盆扩张期,以湖相为主,多砂体,且有短期湖泊水位变浅和成陆过程;指示了盆山构造分异后,盆地加速沉降,湖盆扩张;山体隆起、河流下切,盆地中湖相砂体增多;此时TZ02孔附近为湖相中心,BG10孔为湖泊边缘。4）0~0.62Ma,沉积组合Ⅴ和Ⅵ,湖泊填充期,BG10孔为湖相的沉积中心,而TZ02孔为湖泊的边缘,接受滦河迁移摆动后的沉积物;中更新世后,构造沉降形成湖相,而间冰期发育海相,埋深0~22.5m的海相-河流相更直接地反映了末次冰消期海平面变化过程。

     

一种改进的基于非高斯性最大化的预测反褶积算法

The predictive deconvolution algorithm （PD）, which is based on second-order statistics, assumes that the primaries and the multiples are implicitly orthogonal. However, the seismic data usually do not satisfy this assumption in practice. Since the seismic data （primaries and multiples） have a non-Gaussian distribution, in this paper we present an improved predictive deconvolution algorithm （IPD） by maximizing the non-Gaussianity of the recovered primaries. Applications of the IPD method on synthetic and real seismic datasets show that the proposed method obtains promising results.