Fast radio bursts(FRBs)are short pulses observed in radio frequencies usually originating from cosmological distances.The discovery of FRB 200428 and its X-ray counterpart from the Galactic magnetar SGR J1935+2154suggests that at least some FRBs can be generated by magnetars.However,the majority of X-ray bursts from magnetars are not associated with radio emission.The fact that only in rare cases can an FRB be generated raises the question regarding the special triggering mechanism of FRBs.Here we report long time spin evolution of SGR J1935+2154 until the end of 2022.According to v and v,the spin evolution of SGR J1935+2154 could be divided into two stages.The first stage evolves relatively steady evolution until 2020 April 27.After the burst activity in2020,the spin of SGR J1935+2154 shows strong variations,especially for v.After the burst activity in 2022October,a new spin-down glitch with△v/v=(-7.2±0.6)×10^(-6)is detected around MJD 59876,which is the second event in SGR J1935+2154.At the end,spin frequency and pulse profile do not show variations around the time of FRB 200428 and radio bursts 221014 and 221021,which supply strong clues to constrain the trigger mechanism of FRBs or radio bursts.
断层封闭性既是地下储气库建库阶段需要重点分析的建库条件与储气库运行期间的重要安全指标,同时也是达容达产的地下储气库进行增压扩容时应该进行研究的重要部分。本文以板南区块白6储气库为例,分析储气库断层分布特征,通过三维地质模型,将断层两端地层属性投影至断层模型上,建立断层泥比率(SGR)三维模型,从而对断层封闭性进行定量表征,并与基于数据计算的断层泥比率(SGR)结果进行对比。结果表明:研究区断层封闭主要为岩性对接封闭与断层岩封闭中的泥岩涂抹封闭。断距较大的F1、F4、F5断层两盘砂泥对接,封闭性较好;F3断层断距较小,断层两端砂泥对接、砂砂对接、泥泥对接三种情况均存在,泥比率整体均在50%之上,封闭性较好;F8断层断距较小,断层两端以泥泥对接、砂泥对接为主,少量位置砂砂对接,泥比率在20%以上,多数位置处于40%以上,封闭性较好;F9断层两侧地层以泥泥对接为主,其中砂泥对接区域泥比率整体在15%左右,封闭性较差。Fault sealing is a critical condition to analyze during the construction phase of underground gas storage facilities and a significant safety indicator during their operation. It is also an important aspect to study when increasing pressure and expanding capacity in gas storage facilities that have reached their designed capacity. This paper takes the Bai-6 gas storage facility in the Ban South Block as an example to analyze the fault distribution characteristics of the gas storage. Through a three-dimensional geological model, the stratigraphic properties at both ends of the faults are projected onto the fault model to establish a three-dimensional Shale Gouge Ratio (SGR) model, thereby quantitatively characterizing fault sealing. The results are compared with the SGR results calculated from data. The results show that fault sealing in the study area is mainly due to lithological juxtaposition sealing and fault roc
In October 2022,the magnetar SGR J1935+2154 entered the active outburst state.During the episode,the InsightHXMT satellite carried out a long observation that lasted for 20 days.More than 300 bursts were detected,and a certain amount of persistent radiation signals were also accumulated.This paper mainly introduces the results of persistent radiation profile folding and period search based on Insight-HXMT data.At the same time,the burst phase distribution characteristics,spectral lag results of burst,the spectral characteristics of zero-lag bursts and the time-resolved spectral evolution characteristics of high-flux bursts are reported.We found that there is no significant delay feature during different energy bands for the bursts of SGR J1935+2154.The observed zero-lag burst does not have a unique spectrum.The time-resolved spectrum of the individual burst has consistent spectral types and spectral parameters at different time periods of the burst.We also find that the burst number phase distribution and the burst photon phase distribution have the same tendency to concentrate in specific regions of the persistent emission profile.
Bozhong A Oilfield is located in the northeast of Huanghekou Sag in the Bohai Bay Basin, and is a complex fault block oilfield. The main oil bearing horizon is the lower Minghuazhen Member, belonging to shallow water delta sedimentation. For the rolling exploration and evaluation of adjacent fault blocks, this paper uses the mudstone smear method to analyze and accurately characterize the lithological contact relationship between the two walls of the fault. Based on the establishment of different reservoir docking modes on the two walls of the fault, the sealing parameters are calculated to evaluate the sealing ability of the fault, thereby evaluating its reservoir formation characteristics, and predicting the height of the oil column. The above methods provide geological basis for further rolling expansion and potential tapping in the study area and surrounding areas, and have guiding significance for exploration and rolling potential tapping in similar blocks in the Bohai Sea.
The magnetar SGR 1935+2154 is reported to have an anti-glitch,accompanied by fast radio bursts,and transient pulsed radio emission.In the wind braking model,this triplet event tells people that(1) SGR 1935+2154 does not have a strong particle wind and can be approximated by magnetic dipole braking in the persistent state;(2) its antiglitch is due to an enhanced particle wind,similar to the first anti-glitch in magnetars;(3) its transient pulsed radio emission may be due to a decreasing emission beam during the outburst;(4) the enhanced particle acceleration potential and pulsar death line may not be the dominate factor.