Based on the observations of 36 gPhone gravimeters in 2015, the background noise levels in the seismic frequency band（200-600 s） and sub-seismic band（1-6 h） are calculated. The differences in the PSD（power spectr...Based on the observations of 36 gPhone gravimeters in 2015, the background noise levels in the seismic frequency band（200-600 s） and sub-seismic band（1-6 h） are calculated. The differences in the PSD（power spectrum density） of each band of gPhone gravimetric gauges in different surrounding environments were analyzed and compared with Peterson＇s NLNM（new low-noise model） which is derived from the envelope at the power spectrum density of 75 seismograph stations around the world. The results showed that： the influence of station type on the noise magnitude of gPhone gravimeter is very small; The seismic band noise magnitude（hereinafter referred to as SNM） and the sub-seismic band noise magnitude（hereinafter referred to as SSNM） in the coastal gPhone gravimeter are higher than those of inland stations. Although the local hydrological change has a great influence on the gravity observation, the rainfall is not directly relative to the noise magnitude of the instrument. Except 3 coastal stations, the eight stations which had the highest amplitudes in the SNM were located near the seismic belt. This indicates that the SNM of the gPhone Gravimeter may reflect some seismic information.Compared with the NLNM model, the PSD of the gPhone gravimeter is lower than the NLNM model in the long period band（〈3×10^（-5）Hz）, indicating that the gPhone gravimeter is more suitable for detecting long-period signals（〉10 h） than the seismometer.展开更多
Magnetotransport experiments including tilt fields are performed on ultrahigh mobility L-shaped Hall-bar samples of GaAs/AlGaAs quantum wells. The low-temperature longitudinal resistivity （ρxx） data demonstrate tha...Magnetotransport experiments including tilt fields are performed on ultrahigh mobility L-shaped Hall-bar samples of GaAs/AlGaAs quantum wells. The low-temperature longitudinal resistivity （ρxx） data demonstrate that a striking even-odd asymmetric transport exists along the [110] direction at half filling in N ≥ 2 high Landau levels. Although the origin for the peculiar even-odd asymmetry remains unclear, we propose that the coupling strength between electrons within the same Landau level and between the neighboring two Landau levels should be considered in future studies. The tilt field data show that the in-plane field can suppress the formation of both bubble and stripe phases.展开更多
The overexploitation of underground water leads to the continuous drawdown of groundwater levels, change of water quality and dry-up in dynamic water level observation wells. Due to land subsidence, the well pipes upl...The overexploitation of underground water leads to the continuous drawdown of groundwater levels, change of water quality and dry-up in dynamic water level observation wells. Due to land subsidence, the well pipes uplift and the observation piping systems are damaged. These environmental geology problems can present serious difficulties for the identification of earthquake anomalies by groundwater level observation. Basied on hydrogeological theories and methods, the paper analyzes the relations of the water balance state of aquifers with stress-strain conditions and the water level regime, and then discusses preliminarily the theory and method for identifying well water level anomalies in a groundwater overdraft area. The result shows that we can accurately judge the nature of the anomaly according to the diffusion character of the drawdown funnel in the well area in combination with the aforementioned theory and method and multi-year variation patterns obtained from existing data. The results of the research are helpful for distinguishing the influence of single centralized water pumping from the long-term overdraft of water on the water level, correctly recognizing water level anomalies in the groundwater overdraft area and increasing the level of earthquake analysis and prediction.展开更多
Time-series InSAR analysis（e.g., permanent scatterers（PSInSAR）） has been proven as an effective technology in monitoring ground deformation over urban areas. However, it is a big challenge to apply this technology...Time-series InSAR analysis（e.g., permanent scatterers（PSInSAR）） has been proven as an effective technology in monitoring ground deformation over urban areas. However, it is a big challenge to apply this technology in coastal regions due to the lack of man-made targets. An distributed scatterers interferometric synthetic aperture radar（DSInSAR） is developed to solve the problem of insufficient samples and low reliability in monitoring coastal lowland subsidence, by applying a spatially adaptive filter and an eigendecomposition algorithm to estimating the optimal phase of statistically homogeneous distributed scatterers（DSs）. Twenty-four scenes of COSMO-Sky Med images acquired between 2013 and 2015 are used to retrieve the land subsidence over the Shangyu District on south coast of the Hangzhou Bay, Zhejiang Province, China. The spatial pattern of the land subsidence obtained by the PS-InSAR and the DSInSAR coincides with each other, but the density of the DSs is three point five times higher than the permanent scatterers（PSs）. Validated by precise levelling data over the same period, the DSInSAR method achieves an accuracy of ±5.0 mm/a which is superior to the PS-InSAR with±5.5 mm/a. The land subsidence in the Shangyu District is mainly distributed in the urban areas, industrial towns and land reclamation zones, with a maximum subsidence rate -30.2 mm/a. The analysis of geological data, field investigation and historical reclamation data indicates that human activities and natural compaction of reclamation material are major causes of the detected land subsidence. The results demonstrate that the DSInSAR method has a great potential in monitoring the coastal lowland subsidence and can be used to further investigate subsidence-related environmental issues in coastal regions.展开更多
[ Objective] Effects of sub-chronic intoxication of 1,8-cineole on body weights, routine blood indexes and biochemical indexes of mice were investigated. [Method] One hundred and sixty mice with body weights of 15 -17...[ Objective] Effects of sub-chronic intoxication of 1,8-cineole on body weights, routine blood indexes and biochemical indexes of mice were investigated. [Method] One hundred and sixty mice with body weights of 15 -17 g were randomly divided into four groups （forty mice per group）. Mice were injected to 1, 8 - cineole with doses of 192.45,64. 15 and 21.38 mg/kg body weight （ test groups） and the water solution of tween-80 with a volume fraction of 0.5% （ control group） respectively. Each mouse was administered orally at the dose of 0.2 mL per 10 g body weight once a day consecutively for 90 d. The body weight, routine blood indexes and serum biochemical indexes of mice were determined on the 30^th d, 60^th d, 90^th d and the 30^th d after stopping the administration of 1,8-cineole. [ Result] The effects of 1, 8-cineole on the body weight, routine blood indexes and serum biochemical indexes of mice with the doses of 64.15 and 21.38 mg/kg body weight had no statistically significant difference compared with the control group （P 〉0.05 ）. 1, 8-cineole with the dose of 192.45 mg/kg body weight exhibited different influences on routine blood indexes and serum biochemical indexes of mice after the oral administration of 1,8-cineole for 60 d and 90 d, and statistically significant differences in many blood biochemical indexes were observed （P 〈 0.05 ）. However, the differences in routine blood indexes and serum biochemical indexes were not statistically significant between the test groups and the control group at the 30＇h d after stopping the administration of 1, 8-cineole （ P 〉 0.05）. [Condusion] 1,8-cineole had sub-chronic oral toxicity to mice. The no observed adverse effect level （NOAEL） of 1,8-cineolc was 64.15 mg/kg body weight and the lowest observed adverse effect level （LOAEL） of 1,8-cineole was 192.45 mg/kg body weight. Effects of 1, 8-cineole on blood biochemical indexes of mice were in short term and reversible.展开更多
To increase accuracy of navigation parameters,a perspective measuring complex with intellectual components is developed.Conception of synthesis optimal structure of the measuring complex is realized basing on a select...To increase accuracy of navigation parameters,a perspective measuring complex with intellectual components is developed.Conception of synthesis optimal structure of the measuring complex is realized basing on a selective method using principles of the functional systems.Selection of measured information is finished by original numeric criterion of observation level of state vector components.Prediction is realized by algorithm of self-organization that makes synthesis of the optimal complication.Therefore mechanism of self-regulation is realized and accuracy of the selective navigation complex is increased.展开更多
This paper presents methods for monitoring frost heave, device requirements, testing principals, and data analysis re- quirements, such as manual leveling observation, automatic monitoring （frost heave, frost depth, ...This paper presents methods for monitoring frost heave, device requirements, testing principals, and data analysis re- quirements, such as manual leveling observation, automatic monitoring （frost heave, frost depth, and moisture）, track dynamic detection, and track status detection. We focused on the requirements of subgrade frost heave monitoring for high speed railways, and the relationship of different monitoring methods during different phases of the railway. The com- prehensive monitoring system of high speed railway subgrade frost heave provided the technical support for dynamic design during construction and safe operation of the rail system.展开更多
In this paper,statistics are taken on the co-seismic response of underground fluid in Yunnan to the Nepal M_S8. 1 earthquake,and the co-seismic response characteristics of the water level and water temperature are ana...In this paper,statistics are taken on the co-seismic response of underground fluid in Yunnan to the Nepal M_S8. 1 earthquake,and the co-seismic response characteristics of the water level and water temperature are analyzed and summarized with the digital data. The results show that the Nepal M_S8. 1 earthquake had greater impact on the Yunnan region,and the macro and micro dynamics of fluids showed significant co-seismic response. The earthquake recording capacity of water level and temperature measurement is significantly higher than that of water radon and water quality to this large earthquake; the maximum amplitude and duration of co-seismic response of water level and water temperature vary greatly in different wells. The changing forms are dominated by fluctuation and step rise in water level,and a rising or falling restoration in water temperature. From the records of the main shock and the maximum strong aftershock,we can see that the greater magnitude of earthquake,the higher ratio of the occurrence of co-seismic response,and in the same well,the larger the response amplitude,as well as the longer the duration. The amplitude and duration of co-seismic response recorded by different instruments in a same well are different. Water temperature co-seismic response almost occurred in wells with water level response,indicating that the well water level and water temperature are closely related in co-seismic response,and the well water temperature seismic response was caused mainly by well water level seismic response.展开更多
基金supported by key task project in Sicence for earthquake resilience No.XH17053the National Key Scientific Instrument and Equipment Development Projects of China(Grant No.2012YQ10022506)
文摘Based on the observations of 36 gPhone gravimeters in 2015, the background noise levels in the seismic frequency band（200-600 s） and sub-seismic band（1-6 h） are calculated. The differences in the PSD（power spectrum density） of each band of gPhone gravimetric gauges in different surrounding environments were analyzed and compared with Peterson＇s NLNM（new low-noise model） which is derived from the envelope at the power spectrum density of 75 seismograph stations around the world. The results showed that： the influence of station type on the noise magnitude of gPhone gravimeter is very small; The seismic band noise magnitude（hereinafter referred to as SNM） and the sub-seismic band noise magnitude（hereinafter referred to as SSNM） in the coastal gPhone gravimeter are higher than those of inland stations. Although the local hydrological change has a great influence on the gravity observation, the rainfall is not directly relative to the noise magnitude of the instrument. Except 3 coastal stations, the eight stations which had the highest amplitudes in the SNM were located near the seismic belt. This indicates that the SNM of the gPhone Gravimeter may reflect some seismic information.Compared with the NLNM model, the PSD of the gPhone gravimeter is lower than the NLNM model in the long period band（〈3×10^（-5）Hz）, indicating that the gPhone gravimeter is more suitable for detecting long-period signals（〉10 h） than the seismometer.
基金Supported by the National Basic Research Program of China under Grant Nos 2014CB920904 and 2013CB921702the National Natural Science Foundation of China under Grant Nos 11174340,11174357,91221203 and 91421303+2 种基金the Strategic Priority Research Program B of the Chinese Academy of Sciences under Grant No XDB07010100the Gordon and Betty Moore Foundation through the EPiQS initiative under Grant No GBMF4420the National Science Foundation of MRSEC under Grant No DMR-1420541
文摘Magnetotransport experiments including tilt fields are performed on ultrahigh mobility L-shaped Hall-bar samples of GaAs/AlGaAs quantum wells. The low-temperature longitudinal resistivity （ρxx） data demonstrate that a striking even-odd asymmetric transport exists along the [110] direction at half filling in N ≥ 2 high Landau levels. Although the origin for the peculiar even-odd asymmetry remains unclear, we propose that the coupling strength between electrons within the same Landau level and between the neighboring two Landau levels should be considered in future studies. The tilt field data show that the in-plane field can suppress the formation of both bubble and stripe phases.
基金The research was funded by the National Science and Technology Support Programof China under Grant No2006BAC01B0203
文摘The overexploitation of underground water leads to the continuous drawdown of groundwater levels, change of water quality and dry-up in dynamic water level observation wells. Due to land subsidence, the well pipes uplift and the observation piping systems are damaged. These environmental geology problems can present serious difficulties for the identification of earthquake anomalies by groundwater level observation. Basied on hydrogeological theories and methods, the paper analyzes the relations of the water balance state of aquifers with stress-strain conditions and the water level regime, and then discusses preliminarily the theory and method for identifying well water level anomalies in a groundwater overdraft area. The result shows that we can accurately judge the nature of the anomaly according to the diffusion character of the drawdown funnel in the well area in combination with the aforementioned theory and method and multi-year variation patterns obtained from existing data. The results of the research are helpful for distinguishing the influence of single centralized water pumping from the long-term overdraft of water on the water level, correctly recognizing water level anomalies in the groundwater overdraft area and increasing the level of earthquake analysis and prediction.
文摘Time-series InSAR analysis（e.g., permanent scatterers（PSInSAR）） has been proven as an effective technology in monitoring ground deformation over urban areas. However, it is a big challenge to apply this technology in coastal regions due to the lack of man-made targets. An distributed scatterers interferometric synthetic aperture radar（DSInSAR） is developed to solve the problem of insufficient samples and low reliability in monitoring coastal lowland subsidence, by applying a spatially adaptive filter and an eigendecomposition algorithm to estimating the optimal phase of statistically homogeneous distributed scatterers（DSs）. Twenty-four scenes of COSMO-Sky Med images acquired between 2013 and 2015 are used to retrieve the land subsidence over the Shangyu District on south coast of the Hangzhou Bay, Zhejiang Province, China. The spatial pattern of the land subsidence obtained by the PS-InSAR and the DSInSAR coincides with each other, but the density of the DSs is three point five times higher than the permanent scatterers（PSs）. Validated by precise levelling data over the same period, the DSInSAR method achieves an accuracy of ±5.0 mm/a which is superior to the PS-InSAR with±5.5 mm/a. The land subsidence in the Shangyu District is mainly distributed in the urban areas, industrial towns and land reclamation zones, with a maximum subsidence rate -30.2 mm/a. The analysis of geological data, field investigation and historical reclamation data indicates that human activities and natural compaction of reclamation material are major causes of the detected land subsidence. The results demonstrate that the DSInSAR method has a great potential in monitoring the coastal lowland subsidence and can be used to further investigate subsidence-related environmental issues in coastal regions.
基金Supported by the Incubation Program for Science and Technology Innovative Research Team in Sichuan Province of China(2011-JTD0035)Program of Department of Education in Sichuan Province of China(10ZB050)the Program of Department of Education in Sichuan Province of China(11ZZ022)
文摘[ Objective] Effects of sub-chronic intoxication of 1,8-cineole on body weights, routine blood indexes and biochemical indexes of mice were investigated. [Method] One hundred and sixty mice with body weights of 15 -17 g were randomly divided into four groups （forty mice per group）. Mice were injected to 1, 8 - cineole with doses of 192.45,64. 15 and 21.38 mg/kg body weight （ test groups） and the water solution of tween-80 with a volume fraction of 0.5% （ control group） respectively. Each mouse was administered orally at the dose of 0.2 mL per 10 g body weight once a day consecutively for 90 d. The body weight, routine blood indexes and serum biochemical indexes of mice were determined on the 30^th d, 60^th d, 90^th d and the 30^th d after stopping the administration of 1,8-cineole. [ Result] The effects of 1, 8-cineole on the body weight, routine blood indexes and serum biochemical indexes of mice with the doses of 64.15 and 21.38 mg/kg body weight had no statistically significant difference compared with the control group （P 〉0.05 ）. 1, 8-cineole with the dose of 192.45 mg/kg body weight exhibited different influences on routine blood indexes and serum biochemical indexes of mice after the oral administration of 1,8-cineole for 60 d and 90 d, and statistically significant differences in many blood biochemical indexes were observed （P 〈 0.05 ）. However, the differences in routine blood indexes and serum biochemical indexes were not statistically significant between the test groups and the control group at the 30＇h d after stopping the administration of 1, 8-cineole （ P 〉 0.05）. [Condusion] 1,8-cineole had sub-chronic oral toxicity to mice. The no observed adverse effect level （NOAEL） of 1,8-cineolc was 64.15 mg/kg body weight and the lowest observed adverse effect level （LOAEL） of 1,8-cineole was 192.45 mg/kg body weight. Effects of 1, 8-cineole on blood biochemical indexes of mice were in short term and reversible.
文摘To increase accuracy of navigation parameters,a perspective measuring complex with intellectual components is developed.Conception of synthesis optimal structure of the measuring complex is realized basing on a selective method using principles of the functional systems.Selection of measured information is finished by original numeric criterion of observation level of state vector components.Prediction is realized by algorithm of self-organization that makes synthesis of the optimal complication.Therefore mechanism of self-regulation is realized and accuracy of the selective navigation complex is increased.
基金support from the China Railways Corporation research project entitled"The technical tests for the high speed railway subgrade frost heave prevention in the alpine"(Project No.Z2013-038),"The long term observation of frost-heave technology for Ha-Da high-speed railway during the operation"(Project No.Z2012-062)+2 种基金Optimal design for high-speed railway subgrade structure under different grade and environment(Project No.2014G003-A)support from the railway scientific and technological research and development center called"The mechanism and evolution rule of the graded gravel under freeze and thawing cycles for the high speed railway"(Project No.J2014G003)The disease control technology and equipment of gradating gravel in surface layer of subgrade bed(Project No.2013YJ032)
文摘This paper presents methods for monitoring frost heave, device requirements, testing principals, and data analysis re- quirements, such as manual leveling observation, automatic monitoring （frost heave, frost depth, and moisture）, track dynamic detection, and track status detection. We focused on the requirements of subgrade frost heave monitoring for high speed railways, and the relationship of different monitoring methods during different phases of the railway. The com- prehensive monitoring system of high speed railway subgrade frost heave provided the technical support for dynamic design during construction and safe operation of the rail system.
基金sponsored by the special fund of“A Study on Short-term Seismic Tracking of Strong Earthquakes in the Yunnan Area”of the“Ten Key Projects”in Yunnan Provincethe 2016 Earthquake Trend Tracking Task of China Earthquake Administration(2016010305)the 2015 Earthquake Trend Tracking Task of Earthquake Administration of Yunnan Province
文摘In this paper,statistics are taken on the co-seismic response of underground fluid in Yunnan to the Nepal M_S8. 1 earthquake,and the co-seismic response characteristics of the water level and water temperature are analyzed and summarized with the digital data. The results show that the Nepal M_S8. 1 earthquake had greater impact on the Yunnan region,and the macro and micro dynamics of fluids showed significant co-seismic response. The earthquake recording capacity of water level and temperature measurement is significantly higher than that of water radon and water quality to this large earthquake; the maximum amplitude and duration of co-seismic response of water level and water temperature vary greatly in different wells. The changing forms are dominated by fluctuation and step rise in water level,and a rising or falling restoration in water temperature. From the records of the main shock and the maximum strong aftershock,we can see that the greater magnitude of earthquake,the higher ratio of the occurrence of co-seismic response,and in the same well,the larger the response amplitude,as well as the longer the duration. The amplitude and duration of co-seismic response recorded by different instruments in a same well are different. Water temperature co-seismic response almost occurred in wells with water level response,indicating that the well water level and water temperature are closely related in co-seismic response,and the well water temperature seismic response was caused mainly by well water level seismic response.
