Crustal deformation can provide constraints for studying earthquake rupture and shock wave transmission for the Mw9.0 eastern Japan great earthquake. Using the single- epoch precise point positioning （PPP） method an...Crustal deformation can provide constraints for studying earthquake rupture and shock wave transmission for the Mw9.0 eastern Japan great earthquake. Using the single- epoch precise point positioning （PPP） method and the appropriate positioning flow, we process GPS data from six IGS （International GNSS Service） sites （e.g., MIZU, TSK2, USUD, MTKA, AIRA and KSMV） located in Japan and obtain the positioning results with centimeter scale precision. The displacement time series of the six sites are analyzed using the least squares spectral analysis method to estimate deformations caused by the Mw9.0 mainshock and the Mw7.9 aftershock, and the cumulative displacements after 1 day. Mainshock displacements at station MIZU, the nearest site to the mainshock in the North （N）, East （E）, and Up （U） directions, are -1.202 m, 2.180 m and -0.104 m, respectively, and the cumulative deformations after 1 day are -1.117 m, 2.071 m and -0.072 m, respectively. The displacements at station KSMV, the nearest site to the Mw7.9 aftershock in the N, E and U directions, are -0.032 m, 0.742 m and -0.345 m, respectively. The other sites obviously experienced eastern movements and subsidence. The deformation vectors indicate that the horizontal displacements caused by the earthquake point to the epicenter and rupture. Elastic bounds evidently took place at all sites. The results indicate that the crustal movements and earthquake were part of a megathrust caused by the Pacific Plate sinking under the North American Plate to the northeast of Japan island arc.展开更多
Dendroctonus spp. is one of the most portable pests in imported and ex- ported timber and wooden packages, and it is an important object of the port quarantine. Making rapid and accurate identification of Dendroctonus...Dendroctonus spp. is one of the most portable pests in imported and ex- ported timber and wooden packages, and it is an important object of the port quarantine. Making rapid and accurate identification of Dendroctonus spp. is an im- portant method to reduce the invasion risk of Dendroctonus spp. for China. In this paper, Dendroctonus punctatus, which belongs to the Dendroctonus spp., is intro- duced in detail from the aspects of taxonomic status, biological characteristics, mor- phological characteristics and the invasion risk, providing reference for the identifica- tion of Dendroctonus punctatus in inspection and quarantine.展开更多
The mining area deformation monitoring theory and method using precise point positioning （PPP） ambi- guity resolution （AR） were studied, and an ambiguity fixing model with satellite and receiver combina- tion phas...The mining area deformation monitoring theory and method using precise point positioning （PPP） ambi- guity resolution （AR） were studied, and an ambiguity fixing model with satellite and receiver combina- tion phase delay （CPD） was proposed for zero-differenced PPP ambiguity fixing and its corresponding formula derivation was given. The data processing results for I h at six IGS stations in China show that 93% of ambiguities can be fixed within 10 min and all ambiguities can be fixed within 15 min. After ambi- guity fixing, the positioning accuracy is improved by more than 85% in the E and N directions, with abso- lute positioning accuracy reaching millimeter level, and it was improved by 70% in the U direction, reaching centimeter level; the proposed zero-differenced ambiguity fixing model can effectively improve the convergence rate and positioning accuracy in PPP. Data monitoring continuously conducted for half a year at four COPS stations of Shanxi China Coal Pingshuo Group validated the feasibility of using PPP in mining area deformation monitoring.展开更多
基金supported partially by the National Natural Science Foundation of China(No.40974004 and 40974016)the Key Laboratory of Surveying and Mapping Technology on Island and Reef of NASMG,China(No.2011A01)the Key Laboratory of Advanced Surveying Engineering of NASMG,China(No.TJES1101)
文摘Crustal deformation can provide constraints for studying earthquake rupture and shock wave transmission for the Mw9.0 eastern Japan great earthquake. Using the single- epoch precise point positioning （PPP） method and the appropriate positioning flow, we process GPS data from six IGS （International GNSS Service） sites （e.g., MIZU, TSK2, USUD, MTKA, AIRA and KSMV） located in Japan and obtain the positioning results with centimeter scale precision. The displacement time series of the six sites are analyzed using the least squares spectral analysis method to estimate deformations caused by the Mw9.0 mainshock and the Mw7.9 aftershock, and the cumulative displacements after 1 day. Mainshock displacements at station MIZU, the nearest site to the mainshock in the North （N）, East （E）, and Up （U） directions, are -1.202 m, 2.180 m and -0.104 m, respectively, and the cumulative deformations after 1 day are -1.117 m, 2.071 m and -0.072 m, respectively. The displacements at station KSMV, the nearest site to the Mw7.9 aftershock in the N, E and U directions, are -0.032 m, 0.742 m and -0.345 m, respectively. The other sites obviously experienced eastern movements and subsidence. The deformation vectors indicate that the horizontal displacements caused by the earthquake point to the epicenter and rupture. Elastic bounds evidently took place at all sites. The results indicate that the crustal movements and earthquake were part of a megathrust caused by the Pacific Plate sinking under the North American Plate to the northeast of Japan island arc.
基金Supported by Quarantine Industry Research Special Funds for Public Welfare Projects(201310075-2)Research Project of General Administration of Quality Supervision,Inspection and Quarantine(2012IK276)Changzhou Science and Technology Project(CJ20120027,CJ20130036)~~
文摘Dendroctonus spp. is one of the most portable pests in imported and ex- ported timber and wooden packages, and it is an important object of the port quarantine. Making rapid and accurate identification of Dendroctonus spp. is an im- portant method to reduce the invasion risk of Dendroctonus spp. for China. In this paper, Dendroctonus punctatus, which belongs to the Dendroctonus spp., is intro- duced in detail from the aspects of taxonomic status, biological characteristics, mor- phological characteristics and the invasion risk, providing reference for the identifica- tion of Dendroctonus punctatus in inspection and quarantine.
基金Financial support from the National Natural Science Foundation of China (No. 41074010)the Jiangsu Innovation Works Fund of Postgraduate (No. CXZZ11-0299)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘The mining area deformation monitoring theory and method using precise point positioning （PPP） ambi- guity resolution （AR） were studied, and an ambiguity fixing model with satellite and receiver combina- tion phase delay （CPD） was proposed for zero-differenced PPP ambiguity fixing and its corresponding formula derivation was given. The data processing results for I h at six IGS stations in China show that 93% of ambiguities can be fixed within 10 min and all ambiguities can be fixed within 15 min. After ambi- guity fixing, the positioning accuracy is improved by more than 85% in the E and N directions, with abso- lute positioning accuracy reaching millimeter level, and it was improved by 70% in the U direction, reaching centimeter level; the proposed zero-differenced ambiguity fixing model can effectively improve the convergence rate and positioning accuracy in PPP. Data monitoring continuously conducted for half a year at four COPS stations of Shanxi China Coal Pingshuo Group validated the feasibility of using PPP in mining area deformation monitoring.
