[ Objective ] The paper was to prevent the occurrence of broiler avian influenza virus HS subtype Re-8 strain effectively in the breeding process of broilers. [Method] The maternal antibodies of broilers in Beijing Ba...[ Objective ] The paper was to prevent the occurrence of broiler avian influenza virus HS subtype Re-8 strain effectively in the breeding process of broilers. [Method] The maternal antibodies of broilers in Beijing Baochen Hongwang farm were monitored. According to the disappearance law of maternal antibody, the optimal immune time of broiler avian influenza virus H5 subtype Re-8 strain was determined. [ Result] The maternal antibody level of 2-day-old broilers was relatively high, concentrated at 6 log2 -9 log2, and the antibody positive rate was 100%. The maternal antibody level of 8-day-old broilers concentrated at 4 log2 -6 log2, and the antibody positive rate was 100%. The maternal antibody level of 17-day-old broilers concentrated at 0 log2 -3 log2 , and the antibody positive rate was 0. The average maternal antibody level of 24 - 37 days old broilers was 〈 1 log2, and the antibody positive rate was 0. [ Conclusion ] Although the av- erage maternal antibody level of 8-day-old broilers was higher than 5 log2 , 20% of chickens was 4 log2, and maternal antibody could not protect the flock completely. Therefore, the best primary immunization day age of chicks against avian influenza virus was 8 - 10 days of age.展开更多
The technology of continuously welded rails （CWRs） is important in modern railway track structures. To measure rail stress, resistance strain gauges are preferred due to their good stability, sensitivity, and esist...The technology of continuously welded rails （CWRs） is important in modern railway track structures. To measure rail stress, resistance strain gauges are preferred due to their good stability, sensitivity, and esistance to external interference. Based on the bi-directional strain method, we present a new method for measuring longitudinal rail stress using resistance strain gauges and develop a monitoring device for rail stress to realize long-term and multi-point measurement. Also relevant experimental verification and analysis are conducted. Results indicate that under various constraints the rail stress–strain values can be calculated just with the measured total longitudinal strain and total vertical strain. Considering the measurement error caused by sectional feature of sensors, we put forward a correction equation applicable to different stress conditions. Although the temperature values of the four full-bridge stress gauges can offset each other, the measurement error caused by rail flexural strain can also be eliminated to a certain extent at the same time, the nonuniform distribution of rail cross section temperature and unbalanced flexural strain still affect the measurement error. The experimental results also show that the developed rail-stress-monitoring sensor is suitable for measuring rail stress with reliable working performance.展开更多
[Objective] The study aimed to further understand the genetic quality of Xiphophorus helleri RR-B strain and estimate the feasibility of microsatellite markers in genetic monitoring of aquatic laboratory animals.[Meth...[Objective] The study aimed to further understand the genetic quality of Xiphophorus helleri RR-B strain and estimate the feasibility of microsatellite markers in genetic monitoring of aquatic laboratory animals.[Method] Eighteen microsatellite loci which had polymorphism in wild X. helleri were used for genetic quality analysis of RR-B strain (red eyes and red body) by PCR. [Result] All these 18 microsatellite loci displayed single allelic gene band in 30 individuals of X. helleri RR-B strain and the average homozygote rate reached 100%. [Conclusion] These loci could be used as markers in genetic monitoring of X. helleri RR-B strain, which had obtained fairly high genetic homozygosity by inbreeding for more than 20 generations. This study provided basic data for establishing the molecular genetic monitoring standard of aquatic laboratory animals.展开更多
The fatigue of concrete structures will gradually appear after being subjected to alternating loads for a long time,and the accidents caused by fatigue failure of bridge structures also appear from time to time.Aiming...The fatigue of concrete structures will gradually appear after being subjected to alternating loads for a long time,and the accidents caused by fatigue failure of bridge structures also appear from time to time.Aiming at the problem of degradation of long-span continuous rigid frame bridges due to fatigue and environmental effects,this paper suggests a method to analyze the fatigue degradation mechanism of this type of bridge,which combines long-term in-site monitoring data collected by the health monitoring system(HMS)and fatigue theory.In the paper,the authors mainly carry out the research work in the following aspects:First of all,a long-span continuous rigid frame bridge installed with HMS is used as an example,and a large amount of health monitoring data have been acquired,which can provide efficient information for fatigue in terms of equivalent stress range and cumulative number of stress cycles;next,for calculating the cumulative fatigue damage of the bridge structure,fatigue stress spectrum got by rain flow counting method,S-N curves and damage criteria are used for fatigue damage analysis.Moreover,it was considered a linear accumulation damage through the Palmgren-Miner rule for the counting of stress cycles.The health monitoring data are adopted to obtain fatigue stress data and the rain flow counting method is used to count the amplitude varying fatigue stress.The proposed fatigue reliability approach in the paper can estimate the fatigue damage degree and its evolution law of bridge structures well,and also can help bridge engineers do the assessment of future service duration.展开更多
Composite made of short-cut carbon fiber mat and vinyl ester resin was observed to be an effective sensor for tensile strain up to 6 000με. Based on its strain sensitivity, a skin-like sensitive layer which can cont...Composite made of short-cut carbon fiber mat and vinyl ester resin was observed to be an effective sensor for tensile strain up to 6 000με. Based on its strain sensitivity, a skin-like sensitive layer which can continuously cover the structural surface to sense strain in large area was developed. The sensitive layer was applied to continuously monitor the deformation of a simply supported beam. The result indicates that the fractional change in electrical resistance of the sensitive layer reversibly reflects the beam deformation in each section and describes the distribution of the average strain of the beam. The effect of temperature change on the monitoring was studied by monitoring tests conducted at different temperatures ranging from 20 to 80 ℃, which reveals temperature sensitivity in the sensitive layer and the temperature dependence of the piezoresistive behavior when the temperature exceeds 50 ℃. By the application of differential conaection principle, a method for temperature compensation was established and the gauge factor for the monitoring was dramatically increased. This method was verified experimentally.展开更多
The Kunlunshan Mountain Ms8.1 earthquake, occurred in Nov.14, 2001, is the first event with magnitude more than 8 in the China earthquake monitoring history, specifically at the beginning of digital techniques in prec...The Kunlunshan Mountain Ms8.1 earthquake, occurred in Nov.14, 2001, is the first event with magnitude more than 8 in the China earthquake monitoring history, specifically at the beginning of digital techniques in precursor monitoring networks. Any investigation of recorded data on this earthquake is very important for testing the operation of the digital monitoring networks and understanding the preparation, occurrence, and adjustment of stress/strain of strong continental earthquakes. In this paper we investigated the coseismic response changes of well water level of groundwater and volume strain meter of bore hole in digital earthquake monitoring network of Capital area and its vicinity, due to the Nov.14, 2001 Ms8.1 Kunlun Mountain earthquake. The responding time, shapes or manners, amplitudes, and lasting time of well water level and strain-meters to seismic wave are studied in comparison. Then we discussed the possibility that the response changes of groundwater to strong distant earthquakes can be understood as one kind of observing evidence of stress/strain changes induced by distant earthquake.展开更多
In order to research contemporary crustal movement of Antarctica, China has constructed the deformation monitoring network in the Fildes Strait region,West Antarctica, monitored the network by using DI 20 geodimeter...In order to research contemporary crustal movement of Antarctica, China has constructed the deformation monitoring network in the Fildes Strait region,West Antarctica, monitored the network by using DI 20 geodimeter and GPS instruments, and participated the Antarctic GPS Campaign Observation organized by SCAR as well. During mathematics processing of crustal horizontal deformation observations,a method to bring deformation parameters into the error equations of observations is discussed in this paper. Several classical deformation models,such as rigid body displacement and strain,are introduced. By analyzing the reference datum of static and dynamic geodetic network,the method is developed to set up different additional weight matrix for every different kind of parameter. A series of programs are developed to implementing the method mentioned above and the analysis of West Antarctic Fildes Strait deformation monitoring network. Discussion is also made of GPS monitoring data by using the principle of monitoring network strain analysis in the paper. The research results indicate that the displacement did occur in Fildes rift region,but the displacement was not large,just a slight rift shear movement.展开更多
Wireless interrogation of a rectangular microstrip patch antenna for strain measurement is investigated by simulations.To analyze the antenna performance,a microstrip line-feeding patch antenna at 10 GHz is designed.A...Wireless interrogation of a rectangular microstrip patch antenna for strain measurement is investigated by simulations.To analyze the antenna performance,a microstrip line-feeding patch antenna at 10 GHz is designed.A patch antenna wirelessly fed by a horn is proposed to measure the strain.The direction information of strain detected by the patch antenna is also considered.The strain can be detected both in the width and length directions.It is shown that the strain can be measured wirelessly using a standard horn antenna.This kind of wireless strain-sensing technique offers significant potential for wireless structural health monitoring(SHM),especially for high-end equipment.展开更多
A comprehensive strength monitoring system used on a fixed jacket platform is presented in this paper. The long-term monitoring of W-11-4A platform achieved. Structural responses (strain and acceleration) at selected ...A comprehensive strength monitoring system used on a fixed jacket platform is presented in this paper. The long-term monitoring of W-11-4A platform achieved. Structural responses (strain and acceleration) at selected locations, as well as associated environmental parameters, have been obtained. The emphasis of the paper is placed on the system design, and the instrumentation and operation methodology employed in the monitoring of the structural responses. The performance of the system and the characteristic results obtained during its 13-month operation are also summarized.展开更多
Based on the body strain record of Tiantanghe station from 2008 to 2014,we make a statistical analysis of the relationship between the maximum amplitude of the body strain record and the surface-wave magnitude,epicent...Based on the body strain record of Tiantanghe station from 2008 to 2014,we make a statistical analysis of the relationship between the maximum amplitude of the body strain record and the surface-wave magnitude,epicenter distance of the earthquakes,which occurred in the Chinese mainland and its surrounding areas with MS≥6. 0 and the rest of the world with MS≥7. 0. According to statistical results,we propose a statistical formula between the surface-wave magnitude of earthquake and the maximum amplitude of the body strain record,the epicenter distance: M_S~*= 0. 37 ln A_max+ 0. 57 ln D + 0. 07. We can also derive a theoretical estimation formula for the maximum amplitude: A_max=e^(2. 7(M_S^*-0. 07))D^(-1. 54). This demonstrates that the maximum amplitude of the body strain record increases exponentially with the increase of the surface-wave magnitude, and decreases with the increase of the epicenter distance,and shows a negative correlation with their product. We further discuss the necessity of adding instruments with high frequency sampling to earthquake monitoring, and dicuss the prospects for precise earthquake prediction in future.展开更多
文摘[ Objective ] The paper was to prevent the occurrence of broiler avian influenza virus HS subtype Re-8 strain effectively in the breeding process of broilers. [Method] The maternal antibodies of broilers in Beijing Baochen Hongwang farm were monitored. According to the disappearance law of maternal antibody, the optimal immune time of broiler avian influenza virus H5 subtype Re-8 strain was determined. [ Result] The maternal antibody level of 2-day-old broilers was relatively high, concentrated at 6 log2 -9 log2, and the antibody positive rate was 100%. The maternal antibody level of 8-day-old broilers concentrated at 4 log2 -6 log2, and the antibody positive rate was 100%. The maternal antibody level of 17-day-old broilers concentrated at 0 log2 -3 log2 , and the antibody positive rate was 0. The average maternal antibody level of 24 - 37 days old broilers was 〈 1 log2, and the antibody positive rate was 0. [ Conclusion ] Although the av- erage maternal antibody level of 8-day-old broilers was higher than 5 log2 , 20% of chickens was 4 log2, and maternal antibody could not protect the flock completely. Therefore, the best primary immunization day age of chicks against avian influenza virus was 8 - 10 days of age.
基金the fund support by the National Natural Science Foundation of China (No. 51425804, No. U1234201 and No. U1334203)
文摘The technology of continuously welded rails （CWRs） is important in modern railway track structures. To measure rail stress, resistance strain gauges are preferred due to their good stability, sensitivity, and esistance to external interference. Based on the bi-directional strain method, we present a new method for measuring longitudinal rail stress using resistance strain gauges and develop a monitoring device for rail stress to realize long-term and multi-point measurement. Also relevant experimental verification and analysis are conducted. Results indicate that under various constraints the rail stress–strain values can be calculated just with the measured total longitudinal strain and total vertical strain. Considering the measurement error caused by sectional feature of sensors, we put forward a correction equation applicable to different stress conditions. Although the temperature values of the four full-bridge stress gauges can offset each other, the measurement error caused by rail flexural strain can also be eliminated to a certain extent at the same time, the nonuniform distribution of rail cross section temperature and unbalanced flexural strain still affect the measurement error. The experimental results also show that the developed rail-stress-monitoring sensor is suitable for measuring rail stress with reliable working performance.
基金Supported by Science and Technology Planning Project of Guangdong Province(2005B20301014)Program of National Science and Technology Platform System of China(2005DKA21103)~~
文摘[Objective] The study aimed to further understand the genetic quality of Xiphophorus helleri RR-B strain and estimate the feasibility of microsatellite markers in genetic monitoring of aquatic laboratory animals.[Method] Eighteen microsatellite loci which had polymorphism in wild X. helleri were used for genetic quality analysis of RR-B strain (red eyes and red body) by PCR. [Result] All these 18 microsatellite loci displayed single allelic gene band in 30 individuals of X. helleri RR-B strain and the average homozygote rate reached 100%. [Conclusion] These loci could be used as markers in genetic monitoring of X. helleri RR-B strain, which had obtained fairly high genetic homozygosity by inbreeding for more than 20 generations. This study provided basic data for establishing the molecular genetic monitoring standard of aquatic laboratory animals.
文摘The fatigue of concrete structures will gradually appear after being subjected to alternating loads for a long time,and the accidents caused by fatigue failure of bridge structures also appear from time to time.Aiming at the problem of degradation of long-span continuous rigid frame bridges due to fatigue and environmental effects,this paper suggests a method to analyze the fatigue degradation mechanism of this type of bridge,which combines long-term in-site monitoring data collected by the health monitoring system(HMS)and fatigue theory.In the paper,the authors mainly carry out the research work in the following aspects:First of all,a long-span continuous rigid frame bridge installed with HMS is used as an example,and a large amount of health monitoring data have been acquired,which can provide efficient information for fatigue in terms of equivalent stress range and cumulative number of stress cycles;next,for calculating the cumulative fatigue damage of the bridge structure,fatigue stress spectrum got by rain flow counting method,S-N curves and damage criteria are used for fatigue damage analysis.Moreover,it was considered a linear accumulation damage through the Palmgren-Miner rule for the counting of stress cycles.The health monitoring data are adopted to obtain fatigue stress data and the rain flow counting method is used to count the amplitude varying fatigue stress.The proposed fatigue reliability approach in the paper can estimate the fatigue damage degree and its evolution law of bridge structures well,and also can help bridge engineers do the assessment of future service duration.
基金Funded by the National Natural Science Foundation of China(No.50878169)the Project of State Key Laboratory of Refractories and Metallurgy(Wuhan University of Science and Technology)(No.G201407)
文摘Composite made of short-cut carbon fiber mat and vinyl ester resin was observed to be an effective sensor for tensile strain up to 6 000με. Based on its strain sensitivity, a skin-like sensitive layer which can continuously cover the structural surface to sense strain in large area was developed. The sensitive layer was applied to continuously monitor the deformation of a simply supported beam. The result indicates that the fractional change in electrical resistance of the sensitive layer reversibly reflects the beam deformation in each section and describes the distribution of the average strain of the beam. The effect of temperature change on the monitoring was studied by monitoring tests conducted at different temperatures ranging from 20 to 80 ℃, which reveals temperature sensitivity in the sensitive layer and the temperature dependence of the piezoresistive behavior when the temperature exceeds 50 ℃. By the application of differential conaection principle, a method for temperature compensation was established and the gauge factor for the monitoring was dramatically increased. This method was verified experimentally.
基金supported by Natural Science Foundation of China(41274061 and 40374019)
文摘The Kunlunshan Mountain Ms8.1 earthquake, occurred in Nov.14, 2001, is the first event with magnitude more than 8 in the China earthquake monitoring history, specifically at the beginning of digital techniques in precursor monitoring networks. Any investigation of recorded data on this earthquake is very important for testing the operation of the digital monitoring networks and understanding the preparation, occurrence, and adjustment of stress/strain of strong continental earthquakes. In this paper we investigated the coseismic response changes of well water level of groundwater and volume strain meter of bore hole in digital earthquake monitoring network of Capital area and its vicinity, due to the Nov.14, 2001 Ms8.1 Kunlun Mountain earthquake. The responding time, shapes or manners, amplitudes, and lasting time of well water level and strain-meters to seismic wave are studied in comparison. Then we discussed the possibility that the response changes of groundwater to strong distant earthquakes can be understood as one kind of observing evidence of stress/strain changes induced by distant earthquake.
文摘In order to research contemporary crustal movement of Antarctica, China has constructed the deformation monitoring network in the Fildes Strait region,West Antarctica, monitored the network by using DI 20 geodimeter and GPS instruments, and participated the Antarctic GPS Campaign Observation organized by SCAR as well. During mathematics processing of crustal horizontal deformation observations,a method to bring deformation parameters into the error equations of observations is discussed in this paper. Several classical deformation models,such as rigid body displacement and strain,are introduced. By analyzing the reference datum of static and dynamic geodetic network,the method is developed to set up different additional weight matrix for every different kind of parameter. A series of programs are developed to implementing the method mentioned above and the analysis of West Antarctic Fildes Strait deformation monitoring network. Discussion is also made of GPS monitoring data by using the principle of monitoring network strain analysis in the paper. The research results indicate that the displacement did occur in Fildes rift region,but the displacement was not large,just a slight rift shear movement.
基金supported by the National Natural Science Foundation of China (Nos. 51575015,51235001,51505013)
文摘Wireless interrogation of a rectangular microstrip patch antenna for strain measurement is investigated by simulations.To analyze the antenna performance,a microstrip line-feeding patch antenna at 10 GHz is designed.A patch antenna wirelessly fed by a horn is proposed to measure the strain.The direction information of strain detected by the patch antenna is also considered.The strain can be detected both in the width and length directions.It is shown that the strain can be measured wirelessly using a standard horn antenna.This kind of wireless strain-sensing technique offers significant potential for wireless structural health monitoring(SHM),especially for high-end equipment.
文摘A comprehensive strength monitoring system used on a fixed jacket platform is presented in this paper. The long-term monitoring of W-11-4A platform achieved. Structural responses (strain and acceleration) at selected locations, as well as associated environmental parameters, have been obtained. The emphasis of the paper is placed on the system design, and the instrumentation and operation methodology employed in the monitoring of the structural responses. The performance of the system and the characteristic results obtained during its 13-month operation are also summarized.
基金founded by the Combined Project of Monitoring,Prediction and Research of China Earthquake Administration entitled "Statistical Study on the Earthquake Cases of Imminent Anomaly in Sacks Volume Strain Measurements (154201)"the Operation Maintenance of Shisanling Seismic Station,Institute of Earthquake Science,CEA(40417600105)
文摘Based on the body strain record of Tiantanghe station from 2008 to 2014,we make a statistical analysis of the relationship between the maximum amplitude of the body strain record and the surface-wave magnitude,epicenter distance of the earthquakes,which occurred in the Chinese mainland and its surrounding areas with MS≥6. 0 and the rest of the world with MS≥7. 0. According to statistical results,we propose a statistical formula between the surface-wave magnitude of earthquake and the maximum amplitude of the body strain record,the epicenter distance: M_S~*= 0. 37 ln A_max+ 0. 57 ln D + 0. 07. We can also derive a theoretical estimation formula for the maximum amplitude: A_max=e^(2. 7(M_S^*-0. 07))D^(-1. 54). This demonstrates that the maximum amplitude of the body strain record increases exponentially with the increase of the surface-wave magnitude, and decreases with the increase of the epicenter distance,and shows a negative correlation with their product. We further discuss the necessity of adding instruments with high frequency sampling to earthquake monitoring, and dicuss the prospects for precise earthquake prediction in future.
