Understanding rock behavior is crucial in mine geotechnical engineering to ensure construction efficiency,mitigate rock-related hazards,and promote environmental sustainability.Coda Wave Interferometry(CWI),a non-dest...Understanding rock behavior is crucial in mine geotechnical engineering to ensure construction efficiency,mitigate rock-related hazards,and promote environmental sustainability.Coda Wave Interferometry(CWI),a non-destructive ultrasonic testing method,has been widely employed to assess micro-damage evolution in rocks induced by perturbations in scatterer position,velocity,or source location due to its exceptional sensitivity.However,challenges persist in evaluating cross-scale rock behavior influenced by nonlinear deformation and multi-field interactions under multiple coupled perturbations.A comprehensive review of the perturbation factors affecting rock damage evolution and potential failure mechanisms is essential for presenting available knowledge in a more systematic and structured manner.This review provides an in-depth analysis of the CWI technique,encompassing its origins,theoretical framework,and classical data processing methodologies.Additionally,it explores the diverse applications of CWI in assessing rock behavior under various perturbation factors,including temperature variations,fluid infiltration,and stress conditions,with a particular emphasis on nonlinear deformation and multi-field coupling effects.Furthermore,a novel method for calculating relative velocity changes in coda waves is introduced,enabling a more precise characterization of the entire rock failure process.The study also proposes a cutting-edge concept of ultra-early and refined monitoring and warning technology for mine rock disasters,leveraging the advancements in CWI.Finally,the review highlights the potential future developments of CWI in high-level intelligent mining scenarios,particularly its integration with ambient noise interferometry and microseismic coda wave analysis.This work serves as a valuable reference,contributing to the refinement of CWI applications for assessing complex rock behavior and enhancing the accuracy of rock disaster prediction and early warning systems.展开更多
The approach of evaluating the final scores of multi-criteria decision-making(MCDM)methods according to the strength of association with real-life rankings is interesting for comparing MCDM methods.This approach has r...The approach of evaluating the final scores of multi-criteria decision-making(MCDM)methods according to the strength of association with real-life rankings is interesting for comparing MCDM methods.This approach has recently been applied mostly to financial data.In these studies,where it is emphasized that some methods show more stable success,it would be useful to see the results that will emerge by testing the approach on different data structures more comprehensively.Moreover,not only the final MCDM results but also the performance of normalization techniques and data types(fuzzy or crisp),which are components of MCDM,can be compared using the same approach.These components also have the potential to affect MCDM results directly.In this direction,in our study,the economic performances of G-20(Group of 20)countries,which have different data structures,were calculated over ten different periodic decision matrices.Ten different crisp-based MCDM methods(COPRAS,CODAS,MOORA,TOPSIS,MABAC,VIKOR(S,R,Q),FUCA,and ELECTRE III)with different capabilities were used to better visualize the big picture.The relationships between two different real-life reference anchors and MCDM methods were used as a basis for comparison.The CODAS method develops a high correlation with both anchors in most periods.The most appropriate normalization technique for CODAS was identified using these two anchors.Interestingly,the maximum normalization technique was the most successful among the alternatives(max,min–max,vector,sum,and alternative ranking-based).Moreover,we compared the two main data types by comparing the correlation results of crisp-based and fuzzy-based CODAS.The results were very consistent,and the“Maximum normalization-based fuzzy integrated CODAS procedure”was proposed to decision-makers to measure the economic performance of the countries.展开更多
Coda waves are multiply scattered waves that arrive much later than the major waves. Small seismic velocity variations are observed in reservoirs because of small variations in reservoir properties, which affect the f...Coda waves are multiply scattered waves that arrive much later than the major waves. Small seismic velocity variations are observed in reservoirs because of small variations in reservoir properties, which affect the first arrivals. Hence, first arrivals cannot be used to detect small seismic velocity variations. However, small variations can be reliably detected by the coda waves because of the amplification owing to multiple scattering. We investigate the ability of coda wave interferometry to detect seismic velocity variations and monitor time-lapse reservoir characteristics using numerical simulations and experimental data. We use the Marmousi II model and finite-difference methods to build model seismic data and introduce small seismic velocity variations in the target layer. We examine the model seismic data before and after the changes and observe the coda waves. We find that velocity changes can be detected by coda wave interferometry and demonstrate that coda wave interferometry can be used in monitoring time- lapse reservoir characteristics.展开更多
Two large earthquakes(an earthquake doublet)occurred in south-central Turkey on February 6,2023,causing massive damages and casualties.The magnitudes and the relative sizes of the two mainshocks are essential informat...Two large earthquakes(an earthquake doublet)occurred in south-central Turkey on February 6,2023,causing massive damages and casualties.The magnitudes and the relative sizes of the two mainshocks are essential information for scientific research and public awareness.There are obvious discrepancies among the results that have been reported so far,which may be revised and updated later.Here we applied a novel and reliable long-period coda moment magnitude method to the two large earthquakes.The moment magnitudes(with one standard error)are 7.95±0.013 and 7.86±0.012,respectively,which are larger than all the previous reports.The first mainshock,which matches the largest recorded earthquakes in the Turkish history,is slightly larger than the second one by 0.11±0.035 in magnitude or by 0.04 to 0.18 at 95%confidence level.展开更多
An earthquake with M=6.5 happened on January 15, 2000 in Yaoan of Yunnan Province. After the earthquake, a temporary digital network with 6 detectors around the epicenter area was set up. 402 aftershocks were located ...An earthquake with M=6.5 happened on January 15, 2000 in Yaoan of Yunnan Province. After the earthquake, a temporary digital network with 6 detectors around the epicenter area was set up. 402 aftershocks were located more precisely. According to coda short recording observed, the coda averaging quality factor has been acquired via Satos single scattering model analyses, Qc( f )=49f 0.95,f=1.5~20.0 Hz, which has the attenuation characteristics of high structural active region.展开更多
Ultrasonic coda waves are widely usea to stuay hign-trequency scattering, however, ultrasonic coda waves are strongly affected by interference from by boundary-reflected waves. To understand the effect of boundary-ref...Ultrasonic coda waves are widely usea to stuay hign-trequency scattering, however, ultrasonic coda waves are strongly affected by interference from by boundary-reflected waves. To understand the effect of boundary-reflected waves, we performed ultrasonic experiments using aluminum and shale samples, and the rotating staggered-mesh finite-difference method to simulate the wavefield. We analyzed the wavefield characteristics at the different receiving points and the interference characteristics of the boundary-reflected waves with the ultrasonic coda wave, and the effect of sample geometry on the ultrasonic coda waves. The increase in the aspect ratio of the samples delays the interference effect of the laterally reflected waves and reduces the effect on the ultrasonic coda waves. The main waves interfering with the ultrasonic coda waves are laterally reflected PP-, PS-, PPP-, and PPS-waves. The scattering and attenuation of the high-frequency energy in actual rocks can weaken the interference of laterally reflected waves with the ultrasonic coda waves.展开更多
Transgenic Brassica compestris L.spp.chinensis plants expressing a choline oxidase(codA) gene from Arthrobacter globiformis were obtained through Agrobacterium tumefaciens-mediated transformation.In the transgenic pla...Transgenic Brassica compestris L.spp.chinensis plants expressing a choline oxidase(codA) gene from Arthrobacter globiformis were obtained through Agrobacterium tumefaciens-mediated transformation.In the transgenic plants,codA gene expression and its product transportation to chloroplasts were detected by the enzyme-linked immunosorbent assay(ELISA) examination,immunogold localization,and 1 H-nuclear magnetic resonance( 1 H-NMR) . Stress tolerance was evaluated in the T3 plants under extreme temperature and salinity conditions.The plants of transgenic line 1(L1) showed significantly higher net photosynthetic rate(Pn) and Pn recovery rate under high(45°C,4 h) and low temperature(1°C,48 h) treatments,and higher photosynthetic rate under high salinity conditions(100,200,and 300 mmol/L NaCl,respectively) than the wild-type plants.The enhanced tolerance to high temperature and high salinity stresses in transgenic plants is associated with the accumulation of betaine,which is not found in the wild-type plants.Our results indicate that the introduction of codA gene from Arthrobacter globiformis into Brassica compestris L.spp.chinensis could be a potential strategy for improving the plant tolerance to multiple stresses.展开更多
ased on the empirical formulation formed from coda observations, the digital waveforms from 33 local events with magnitude ML ranging between 2.1 and 3.5, recorded at Changli station of Beijing Telemetered Seismograph...ased on the empirical formulation formed from coda observations, the digital waveforms from 33 local events with magnitude ML ranging between 2.1 and 3.5, recorded at Changli station of Beijing Telemetered Seismographic Network from 1989 to 1991, are used to compute coda Q for the Changli region and the source factors of all earthquakes by single-station coda method. Furthermore, assuming a certain source model, we have obtained the station site frequency response and source spectra, as well as source parameters such as corner frequencies, seismic moments and stress drops and so on. Their variations with time are monitored before and after larger earthquakes. Because the coda method can more effectively reduce the influence of source radiation pattern and a particular propagation path than direct wave method, more data can be used and more accurate results can be obtained, which provided a possible approach to study the source properties and reveal the variation of source parameters before larger earthquakes.展开更多
On the basis of previous studies, this paper in studying the coda Q-valuc of near shocks, has proposed using the sampling depth to describe the effect of lapse time on the Q-value, and has investigated the dependence...On the basis of previous studies, this paper in studying the coda Q-valuc of near shocks, has proposed using the sampling depth to describe the effect of lapse time on the Q-value, and has investigated the dependence of coda wave of earthquakes on frequency and sampling depth. Analysis of digital seismograms recorded by the Yinchuan Telemetric Seismic Network, Ningxia, shows that not only the coda wave Q-value of shocks is strongly dependent on frequency but also its dependence on Samling depth cannot be neglected. In the commonly used formula that describes the dependence cbaracteristics of coda Q-value of endquakes, Q = Qof', the parameter Qo rises obviously whilc n drops when the sampling depth increases, and their changes can be fitted by linear relations. This paper has explained such a characteristic. Whether this characteristic exists universally needs to be verified by more study results because the genetic mechanism of coda wave of earthquakes is more complex.展开更多
基金supported by the National Key Research and Development Program of China(Fund for Young Scientists 2021YFC2900400)Chongqing Outstanding Youth Science Fund project(CSTB2023NSCQ-JQX0027).
文摘Understanding rock behavior is crucial in mine geotechnical engineering to ensure construction efficiency,mitigate rock-related hazards,and promote environmental sustainability.Coda Wave Interferometry(CWI),a non-destructive ultrasonic testing method,has been widely employed to assess micro-damage evolution in rocks induced by perturbations in scatterer position,velocity,or source location due to its exceptional sensitivity.However,challenges persist in evaluating cross-scale rock behavior influenced by nonlinear deformation and multi-field interactions under multiple coupled perturbations.A comprehensive review of the perturbation factors affecting rock damage evolution and potential failure mechanisms is essential for presenting available knowledge in a more systematic and structured manner.This review provides an in-depth analysis of the CWI technique,encompassing its origins,theoretical framework,and classical data processing methodologies.Additionally,it explores the diverse applications of CWI in assessing rock behavior under various perturbation factors,including temperature variations,fluid infiltration,and stress conditions,with a particular emphasis on nonlinear deformation and multi-field coupling effects.Furthermore,a novel method for calculating relative velocity changes in coda waves is introduced,enabling a more precise characterization of the entire rock failure process.The study also proposes a cutting-edge concept of ultra-early and refined monitoring and warning technology for mine rock disasters,leveraging the advancements in CWI.Finally,the review highlights the potential future developments of CWI in high-level intelligent mining scenarios,particularly its integration with ambient noise interferometry and microseismic coda wave analysis.This work serves as a valuable reference,contributing to the refinement of CWI applications for assessing complex rock behavior and enhancing the accuracy of rock disaster prediction and early warning systems.
文摘The approach of evaluating the final scores of multi-criteria decision-making(MCDM)methods according to the strength of association with real-life rankings is interesting for comparing MCDM methods.This approach has recently been applied mostly to financial data.In these studies,where it is emphasized that some methods show more stable success,it would be useful to see the results that will emerge by testing the approach on different data structures more comprehensively.Moreover,not only the final MCDM results but also the performance of normalization techniques and data types(fuzzy or crisp),which are components of MCDM,can be compared using the same approach.These components also have the potential to affect MCDM results directly.In this direction,in our study,the economic performances of G-20(Group of 20)countries,which have different data structures,were calculated over ten different periodic decision matrices.Ten different crisp-based MCDM methods(COPRAS,CODAS,MOORA,TOPSIS,MABAC,VIKOR(S,R,Q),FUCA,and ELECTRE III)with different capabilities were used to better visualize the big picture.The relationships between two different real-life reference anchors and MCDM methods were used as a basis for comparison.The CODAS method develops a high correlation with both anchors in most periods.The most appropriate normalization technique for CODAS was identified using these two anchors.Interestingly,the maximum normalization technique was the most successful among the alternatives(max,min–max,vector,sum,and alternative ranking-based).Moreover,we compared the two main data types by comparing the correlation results of crisp-based and fuzzy-based CODAS.The results were very consistent,and the“Maximum normalization-based fuzzy integrated CODAS procedure”was proposed to decision-makers to measure the economic performance of the countries.
基金sponsored by the 973 Program of China(No.2013CB228604)the Natural Science Foundation of Shandong Province(No.ZR2013DQ020)+1 种基金the Fundamental Research Funds for the Central Universities(No.15CX08002A)the National Natural Science Foundation of China(No.41374123)
文摘Coda waves are multiply scattered waves that arrive much later than the major waves. Small seismic velocity variations are observed in reservoirs because of small variations in reservoir properties, which affect the first arrivals. Hence, first arrivals cannot be used to detect small seismic velocity variations. However, small variations can be reliably detected by the coda waves because of the amplification owing to multiple scattering. We investigate the ability of coda wave interferometry to detect seismic velocity variations and monitor time-lapse reservoir characteristics using numerical simulations and experimental data. We use the Marmousi II model and finite-difference methods to build model seismic data and introduce small seismic velocity variations in the target layer. We examine the model seismic data before and after the changes and observe the coda waves. We find that velocity changes can be detected by coda wave interferometry and demonstrate that coda wave interferometry can be used in monitoring time- lapse reservoir characteristics.
基金the National Key R&D Program of China(No.2022YFF0800601)the National Natural Science Foundation of China(No.U1939204).
文摘Two large earthquakes(an earthquake doublet)occurred in south-central Turkey on February 6,2023,causing massive damages and casualties.The magnitudes and the relative sizes of the two mainshocks are essential information for scientific research and public awareness.There are obvious discrepancies among the results that have been reported so far,which may be revised and updated later.Here we applied a novel and reliable long-period coda moment magnitude method to the two large earthquakes.The moment magnitudes(with one standard error)are 7.95±0.013 and 7.86±0.012,respectively,which are larger than all the previous reports.The first mainshock,which matches the largest recorded earthquakes in the Turkish history,is slightly larger than the second one by 0.11±0.035 in magnitude or by 0.04 to 0.18 at 95%confidence level.
文摘An earthquake with M=6.5 happened on January 15, 2000 in Yaoan of Yunnan Province. After the earthquake, a temporary digital network with 6 detectors around the epicenter area was set up. 402 aftershocks were located more precisely. According to coda short recording observed, the coda averaging quality factor has been acquired via Satos single scattering model analyses, Qc( f )=49f 0.95,f=1.5~20.0 Hz, which has the attenuation characteristics of high structural active region.
基金supported by the Strategic Leading Science and Technology Programme(Class B)of the Chinese Academy of Sciences(No.XDB10010400)
文摘Ultrasonic coda waves are widely usea to stuay hign-trequency scattering, however, ultrasonic coda waves are strongly affected by interference from by boundary-reflected waves. To understand the effect of boundary-reflected waves, we performed ultrasonic experiments using aluminum and shale samples, and the rotating staggered-mesh finite-difference method to simulate the wavefield. We analyzed the wavefield characteristics at the different receiving points and the interference characteristics of the boundary-reflected waves with the ultrasonic coda wave, and the effect of sample geometry on the ultrasonic coda waves. The increase in the aspect ratio of the samples delays the interference effect of the laterally reflected waves and reduces the effect on the ultrasonic coda waves. The main waves interfering with the ultrasonic coda waves are laterally reflected PP-, PS-, PPP-, and PPS-waves. The scattering and attenuation of the high-frequency energy in actual rocks can weaken the interference of laterally reflected waves with the ultrasonic coda waves.
基金Project supported by the National Science Foundation of China (No.30571146)the National Key Basic Research Special Foundation of China(No.G1999011700)
文摘Transgenic Brassica compestris L.spp.chinensis plants expressing a choline oxidase(codA) gene from Arthrobacter globiformis were obtained through Agrobacterium tumefaciens-mediated transformation.In the transgenic plants,codA gene expression and its product transportation to chloroplasts were detected by the enzyme-linked immunosorbent assay(ELISA) examination,immunogold localization,and 1 H-nuclear magnetic resonance( 1 H-NMR) . Stress tolerance was evaluated in the T3 plants under extreme temperature and salinity conditions.The plants of transgenic line 1(L1) showed significantly higher net photosynthetic rate(Pn) and Pn recovery rate under high(45°C,4 h) and low temperature(1°C,48 h) treatments,and higher photosynthetic rate under high salinity conditions(100,200,and 300 mmol/L NaCl,respectively) than the wild-type plants.The enhanced tolerance to high temperature and high salinity stresses in transgenic plants is associated with the accumulation of betaine,which is not found in the wild-type plants.Our results indicate that the introduction of codA gene from Arthrobacter globiformis into Brassica compestris L.spp.chinensis could be a potential strategy for improving the plant tolerance to multiple stresses.
文摘ased on the empirical formulation formed from coda observations, the digital waveforms from 33 local events with magnitude ML ranging between 2.1 and 3.5, recorded at Changli station of Beijing Telemetered Seismographic Network from 1989 to 1991, are used to compute coda Q for the Changli region and the source factors of all earthquakes by single-station coda method. Furthermore, assuming a certain source model, we have obtained the station site frequency response and source spectra, as well as source parameters such as corner frequencies, seismic moments and stress drops and so on. Their variations with time are monitored before and after larger earthquakes. Because the coda method can more effectively reduce the influence of source radiation pattern and a particular propagation path than direct wave method, more data can be used and more accurate results can be obtained, which provided a possible approach to study the source properties and reveal the variation of source parameters before larger earthquakes.
文摘On the basis of previous studies, this paper in studying the coda Q-valuc of near shocks, has proposed using the sampling depth to describe the effect of lapse time on the Q-value, and has investigated the dependence of coda wave of earthquakes on frequency and sampling depth. Analysis of digital seismograms recorded by the Yinchuan Telemetric Seismic Network, Ningxia, shows that not only the coda wave Q-value of shocks is strongly dependent on frequency but also its dependence on Samling depth cannot be neglected. In the commonly used formula that describes the dependence cbaracteristics of coda Q-value of endquakes, Q = Qof', the parameter Qo rises obviously whilc n drops when the sampling depth increases, and their changes can be fitted by linear relations. This paper has explained such a characteristic. Whether this characteristic exists universally needs to be verified by more study results because the genetic mechanism of coda wave of earthquakes is more complex.
