On September 8, 2018, an M_S 5.9 earthquake struck Mojiang, a county in Yunnan Province, China. We collect near-field seismic recordings(epicentral distances less than 200 km) to relocate the mainshock and the aftersh...On September 8, 2018, an M_S 5.9 earthquake struck Mojiang, a county in Yunnan Province, China. We collect near-field seismic recordings(epicentral distances less than 200 km) to relocate the mainshock and the aftershocks within the first 60 hours to determine the focal mechanism solutions of the mainshock and some of the aftershocks and to invert for the finite-fault model of the mainshock.The focal mechanism solution of the mainshock and the relocation results of the aftershocks constrain the mainshock on a nearly vertical fault plane striking northeast and dipping to the southeast. The inversion of the finite-fault model reveals only a single slip asperity on the fault plane. The major slip is distributed above the initiation point, ～14 km wide along the down-dip direction and ～14 km long along the strike direction, with a maximal slip of ～22 cm at a depth of ～6 km. The focal mechanism solutions of the aftershocks show that most of the aftershocks are of the strike-slip type, a number of them are of the normal-slip type, and only a few of them are of the thrust-slip type.On average, strike-slip is dominant on the fault plane of the mainshock, as the focal mechanism solution of the mainshock suggests, but when examined in detail, slight thrust-slip appears on the southwest of the fault plane while an obvious part of normal-slip appears on the northeast, which is consistent with what the focal mechanism solutions of the aftershocks display. The multiple types of aftershock focal mechanism solutions and the slip details of the mainshock both suggest a complex tectonic setting, stress setting, or both. The intensity contours predicted exhibit a longer axis trending from northeast to southwest and a maximal intensity of Ⅷ around the epicenter and in the northwest.展开更多
As an achievement of the cooperation with Japan,TOA electromagnetic observation station was established with an 800 m borehole antenna and put into service in 1992 in Dali,Yunnan province,China.Li Wuxian et al.(2003)s...As an achievement of the cooperation with Japan,TOA electromagnetic observation station was established with an 800 m borehole antenna and put into service in 1992 in Dali,Yunnan province,China.Li Wuxian et al.(2003)summarized main anomalous variation characters by analyzing 23 strong earthquakes with magnitudes more than 5.0 recorded in the first ten years.This work mainly presents the electromagnetic changes prior to the last Mojiang MS5.9 earthquake on September 8,2018.First of all,the initial weak signals appeared in two ULF channels out of three observing channels(CH10.01-0.10 Hz,CH20.1-1.0 Hz and CH31-9 kHz)on May 30,2018 at Dali TOA electromagnetic station.The information recorded was characterized by wave-like changes with magnitudes of ACH1≤0.26 mV in CH1 and pulse-like impulses of ACH2≤0.6 mV in CH2,respectively.Then,abnormal information gradually enhanced either in magnitudes or in occurrence frequency.Pulse-like signals were full of lattices of recording paper for CH2 during June24-25 and slopped over the recording paper during June 28-29,with the magnitudes being greater than or equal to 10 mV.At the same time,the clear wave-like signals also appeared in CH1 with a maximum magnitude of^0.6 mV on June 28 and reached its climax.From then on,the information started to decrease from the end of July and only weak signals occasionally occurred till the end of August 2018,when obvious anomaly was recorded again in two ULF channels with maximum magnitudes of ACH1~0.2 mV and ACH2~0.3 mV respectively.Generally,these signals did not appear continuously but group by group and accumulated intensively only in ULF band instead of VLF band during the total period.10 days later,the Mojiang MS5.9 earthquake occurred on September 8,2018,300 km away from Dali TOA station,and a coseismic response was also recorded at this time.Thus,these ULF electromagnetic abnormities could be probably attributed to the Mojiang event.展开更多
The distribution of the intensity of the Mojiang M_S5.9 earthquake in Yunnan Province is expounded, and the damage characteristics of buildings and the damage ratio and seismic damage index of various building structu...The distribution of the intensity of the Mojiang M_S5.9 earthquake in Yunnan Province is expounded, and the damage characteristics of buildings and the damage ratio and seismic damage index of various building structures in each intensity area are compared with those of The Chinese Seismic Intensity Scale. The main basis and method of seismic intensity assessment are discussed in this paper. It is concluded that: ① The seismic intensity should be based on the earthquake damage of the housing structure, which takes up a high ratio in the seismic intensity assessment. It is recommended that seismic intensity is estimated by calculating the average seismic damage index. ② The highest intensity of the Mojiang M_S5.9 earthquake is Ⅷ degrees, with the long axis trending in the north-west direction. The area above Ⅶ degrees is 5,180 km^2. ③ The intensity distribution of the Mojiang M_S5.9 earthquake meets the national standard and the distribution law of seismic intensity in Yunnan.展开更多
Geological and geochemical characteristics of cherts of the low\|middle parts of the Jinchang Formation indicate that cherts are associated with hydrothermal sedimentation, but the middle\|upper parts of the Jinchang ...Geological and geochemical characteristics of cherts of the low\|middle parts of the Jinchang Formation indicate that cherts are associated with hydrothermal sedimentation, but the middle\|upper parts of the Jinchang Formation are mixed with normal sediments. The cherts are characterized by high Fe, As, Sb, Bi and Ga, low Al and total REE, negative Ce anomaly and HREE enrichment. Their \{δ\{\}\+\{18\}O\} values show that the forming temperatures of the cherts range from 128 ℃ to 146 ℃.展开更多
Diagenetic-metallogenic ages of pyritic cherts formed by the syn-sedimentation of hydrothermal vent and ages of the Jinchang Rock Formation in the Mojiang large nickel-gold deposit in the Ailaoshan gold metallogenic b...Diagenetic-metallogenic ages of pyritic cherts formed by the syn-sedimentation of hydrothermal vent and ages of the Jinchang Rock Formation in the Mojiang large nickel-gold deposit in the Ailaoshan gold metallogenic belt have been discussed on the basis of chronology of isotopic geochemistry. Nickel-gold-bearing pyritic cherts in the mining were formed by syn-sedimentation of hydrothermal vent in the Late Devonian, i.e. age by Sm-Nd isochronal method (t) = (358±8.6) (2σ) Ma and age by Rb-Sr isochronal method (t) = (354.7±0.72) (2σ) Ma. On the other hand, deep-water cherts from the Jinchang Rock Formation of the Upper Devonian in the area were initiated at the same time; that is, age by Sm-Nd isochronal method (t) = (359(+21) (2(7) Ma and age by Rb-Sr isochronal method (t) = (358.02±0.30) (2σ) Ma.展开更多
The emerging viruses within the genus Henipavirus in the family Paramyxoviridae pose a great threat to public biosafety.To develop a quadruple real-time fluorescence-based quantitative reverse transcription polymerase...The emerging viruses within the genus Henipavirus in the family Paramyxoviridae pose a great threat to public biosafety.To develop a quadruple real-time fluorescence-based quantitative reverse transcription polymerase chain reaction(qRT-PCR)assay is pivotal for the early warning of the potential of zoonotic infectious diseases.Specific primers and probes were designed for the relatively conserved regions based on whole genome sequences of Langya virus(LayV),Mojiang virus(MojV),Nipah virus(NiV),and Cedar virus(CedV),followed by the establishment of a quadruple real-time fluorescence-based qRT-PCR detection method.No cross-reactivity was observed with other viral nucleic acids.The optimal linear detection range for LayV,MojV,NiV,and CedV was 10^(1)-10^(8)copies/μL,and the lower limit of detection was 10 copies/μL.Three different DNA concentrations of LayV,MojV,NiV,and CedV(10^(4),10^(5),and 10^(6)copies/μL)were tested 14 times,achieving good repeatability.The standard deviation of the cycle threshold values for each concentration was<0.5 and the coefficient of variation was<3%.Furthermore,the amplification efficiency of quadruple real-time fluorescence-based qRT-PCR was>90%,and the correlation coefficient was>0.99.The established quadru-ple real-time fluorescence-based qRT-PCR assay for the detection of LayV,MojV,NiV,and CedV exhibits good sensitivity,specificity,and repeatability.Therefore,it can be used to detect Henipavirus and other related clinical specimens.展开更多
基金supported by the National Natural Science Foundation of China(project 41804088)the Special Fund of the Institute of Geophysics,China Earthquake Administration(project DQJB19B08)
文摘On September 8, 2018, an M_S 5.9 earthquake struck Mojiang, a county in Yunnan Province, China. We collect near-field seismic recordings(epicentral distances less than 200 km) to relocate the mainshock and the aftershocks within the first 60 hours to determine the focal mechanism solutions of the mainshock and some of the aftershocks and to invert for the finite-fault model of the mainshock.The focal mechanism solution of the mainshock and the relocation results of the aftershocks constrain the mainshock on a nearly vertical fault plane striking northeast and dipping to the southeast. The inversion of the finite-fault model reveals only a single slip asperity on the fault plane. The major slip is distributed above the initiation point, ～14 km wide along the down-dip direction and ～14 km long along the strike direction, with a maximal slip of ～22 cm at a depth of ～6 km. The focal mechanism solutions of the aftershocks show that most of the aftershocks are of the strike-slip type, a number of them are of the normal-slip type, and only a few of them are of the thrust-slip type.On average, strike-slip is dominant on the fault plane of the mainshock, as the focal mechanism solution of the mainshock suggests, but when examined in detail, slight thrust-slip appears on the southwest of the fault plane while an obvious part of normal-slip appears on the northeast, which is consistent with what the focal mechanism solutions of the aftershocks display. The multiple types of aftershock focal mechanism solutions and the slip details of the mainshock both suggest a complex tectonic setting, stress setting, or both. The intensity contours predicted exhibit a longer axis trending from northeast to southwest and a maximal intensity of Ⅷ around the epicenter and in the northwest.
基金the National Natural Science Foundation of China(41774084)
文摘As an achievement of the cooperation with Japan,TOA electromagnetic observation station was established with an 800 m borehole antenna and put into service in 1992 in Dali,Yunnan province,China.Li Wuxian et al.(2003)summarized main anomalous variation characters by analyzing 23 strong earthquakes with magnitudes more than 5.0 recorded in the first ten years.This work mainly presents the electromagnetic changes prior to the last Mojiang MS5.9 earthquake on September 8,2018.First of all,the initial weak signals appeared in two ULF channels out of three observing channels(CH10.01-0.10 Hz,CH20.1-1.0 Hz and CH31-9 kHz)on May 30,2018 at Dali TOA electromagnetic station.The information recorded was characterized by wave-like changes with magnitudes of ACH1≤0.26 mV in CH1 and pulse-like impulses of ACH2≤0.6 mV in CH2,respectively.Then,abnormal information gradually enhanced either in magnitudes or in occurrence frequency.Pulse-like signals were full of lattices of recording paper for CH2 during June24-25 and slopped over the recording paper during June 28-29,with the magnitudes being greater than or equal to 10 mV.At the same time,the clear wave-like signals also appeared in CH1 with a maximum magnitude of^0.6 mV on June 28 and reached its climax.From then on,the information started to decrease from the end of July and only weak signals occasionally occurred till the end of August 2018,when obvious anomaly was recorded again in two ULF channels with maximum magnitudes of ACH1~0.2 mV and ACH2~0.3 mV respectively.Generally,these signals did not appear continuously but group by group and accumulated intensively only in ULF band instead of VLF band during the total period.10 days later,the Mojiang MS5.9 earthquake occurred on September 8,2018,300 km away from Dali TOA station,and a coseismic response was also recorded at this time.Thus,these ULF electromagnetic abnormities could be probably attributed to the Mojiang event.
基金sponsored by the Sparkle Program of Earthquake Science,CEA(XH17032)
文摘The distribution of the intensity of the Mojiang M_S5.9 earthquake in Yunnan Province is expounded, and the damage characteristics of buildings and the damage ratio and seismic damage index of various building structures in each intensity area are compared with those of The Chinese Seismic Intensity Scale. The main basis and method of seismic intensity assessment are discussed in this paper. It is concluded that: ① The seismic intensity should be based on the earthquake damage of the housing structure, which takes up a high ratio in the seismic intensity assessment. It is recommended that seismic intensity is estimated by calculating the average seismic damage index. ② The highest intensity of the Mojiang M_S5.9 earthquake is Ⅷ degrees, with the long axis trending in the north-west direction. The area above Ⅶ degrees is 5,180 km^2. ③ The intensity distribution of the Mojiang M_S5.9 earthquake meets the national standard and the distribution law of seismic intensity in Yunnan.
文摘Geological and geochemical characteristics of cherts of the low\|middle parts of the Jinchang Formation indicate that cherts are associated with hydrothermal sedimentation, but the middle\|upper parts of the Jinchang Formation are mixed with normal sediments. The cherts are characterized by high Fe, As, Sb, Bi and Ga, low Al and total REE, negative Ce anomaly and HREE enrichment. Their \{δ\{\}\+\{18\}O\} values show that the forming temperatures of the cherts range from 128 ℃ to 146 ℃.
基金This work was supported by the National Natural Science Foundation of China (Grants No. 49925309)the State Key Project of Fundamental Research Planning (Grants No. 1999043200) and the Yunnan Province-Chinese Academy of Sciences Corporation Project (G
文摘Diagenetic-metallogenic ages of pyritic cherts formed by the syn-sedimentation of hydrothermal vent and ages of the Jinchang Rock Formation in the Mojiang large nickel-gold deposit in the Ailaoshan gold metallogenic belt have been discussed on the basis of chronology of isotopic geochemistry. Nickel-gold-bearing pyritic cherts in the mining were formed by syn-sedimentation of hydrothermal vent in the Late Devonian, i.e. age by Sm-Nd isochronal method (t) = (358±8.6) (2σ) Ma and age by Rb-Sr isochronal method (t) = (354.7±0.72) (2σ) Ma. On the other hand, deep-water cherts from the Jinchang Rock Formation of the Upper Devonian in the area were initiated at the same time; that is, age by Sm-Nd isochronal method (t) = (359(+21) (2(7) Ma and age by Rb-Sr isochronal method (t) = (358.02±0.30) (2σ) Ma.
基金supported by the National Key R&D Program of China(Grant No.2022YFC2601200).
文摘The emerging viruses within the genus Henipavirus in the family Paramyxoviridae pose a great threat to public biosafety.To develop a quadruple real-time fluorescence-based quantitative reverse transcription polymerase chain reaction(qRT-PCR)assay is pivotal for the early warning of the potential of zoonotic infectious diseases.Specific primers and probes were designed for the relatively conserved regions based on whole genome sequences of Langya virus(LayV),Mojiang virus(MojV),Nipah virus(NiV),and Cedar virus(CedV),followed by the establishment of a quadruple real-time fluorescence-based qRT-PCR detection method.No cross-reactivity was observed with other viral nucleic acids.The optimal linear detection range for LayV,MojV,NiV,and CedV was 10^(1)-10^(8)copies/μL,and the lower limit of detection was 10 copies/μL.Three different DNA concentrations of LayV,MojV,NiV,and CedV(10^(4),10^(5),and 10^(6)copies/μL)were tested 14 times,achieving good repeatability.The standard deviation of the cycle threshold values for each concentration was<0.5 and the coefficient of variation was<3%.Furthermore,the amplification efficiency of quadruple real-time fluorescence-based qRT-PCR was>90%,and the correlation coefficient was>0.99.The established quadru-ple real-time fluorescence-based qRT-PCR assay for the detection of LayV,MojV,NiV,and CedV exhibits good sensitivity,specificity,and repeatability.Therefore,it can be used to detect Henipavirus and other related clinical specimens.
