The rubber cylinder is a key component for maintaining the sealing pressure of the packer,particularly in deep underground wells.The stress relaxation of materials,as a typical feature of viscoelasticity,has become on...The rubber cylinder is a key component for maintaining the sealing pressure of the packer,particularly in deep underground wells.The stress relaxation of materials,as a typical feature of viscoelasticity,has become one of the main factors causing the failure of rubber cylinders in service.In the present study,a visco-hyperelastic model for the sealing rubber considering different strain levels is proposed based on the Prony series.Subsequently,the uniaxial compression stress relaxation experiments are conducted on the sealing rubber under different temperatures and strain levels,and the model parameters are thereby identified.As a case study,the proposed model is incorporated into the ABAQUS software via the UM AT subroutine,and the finite element simulation of the sealing packer is carried out.The results show that the sealing performance of the packer improves with a decrease in temperature or an increase in strain level.It is also noted that a large strain level can lead to the protrusion of the shoulder of the rubber cylinder.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
Effects of attenuated highly pathogenic pig reproductive and respiratory syndrome（HP-PRRS）TJM-F92 strain vaccine on immune antibody level against classical swine fever（CSF）and foot-and-mouth disease（FMD）were stu...Effects of attenuated highly pathogenic pig reproductive and respiratory syndrome（HP-PRRS）TJM-F92 strain vaccine on immune antibody level against classical swine fever（CSF）and foot-and-mouth disease（FMD）were studied from October 8 to November 12 in 2014,in order to optimize vaccination program of CSF,HP-PRRS and FMD and to provide scientific guidance for animal disease control and prevention work.The results showed that attenuated HP-PRRS（TJMF92 strain）vaccine had no significant effect on immune antibody level of hog cholera lapinized virus（HCLV,ST passage cell vaccine）attenuated vaccine and FMD-O inactivated vaccines（OZK/93 strain）,and single or combined use of three vaccines received good immunization effects.展开更多
Colorectal cancer(CRC)is the third leading cancer globally.Metagenomics has been widely used to analyze the association between the gut microbiota and CRC based on bacterial genus-or species-level comparisons,providin...Colorectal cancer(CRC)is the third leading cancer globally.Metagenomics has been widely used to analyze the association between the gut microbiota and CRC based on bacterial genus-or species-level comparisons,providing evidence of dysbiosis in CRC development.However,this kind of analysis is unable to provide strain-level information for understanding the individual role of a species in CRC.Here,we used culturomics to isolate CRC mucosal samples and selected 158 Escherichia coli strains to reveal their differences in both genomics and functions by means of phylogenetic analysis and inflammatory induction based on cell and animal experiments.Through genomic comparison,these strains were divided into five phylogroups.The representative strains of each phylogroup significantly induced different levels of cytokine secretion by human leukemic monocyte(THP-1 cell)-based Transwell and animal experiments.Further bioinformatic analysis revealed different profiles of single-nucleotide polymorphisms,genes,and metabolic pathways in the different phylogroups,which can improve the current understanding of the phenotypic differences between these strains.The strain differences revealed in both genomics and functions indicate that the microbiota’s function at the strain level should be investigated in order to understand the interacting mechanisms between hosts and gut bacteria.展开更多
Nonlinear elastidty of the earth medium produces a numerical difference between the dynamic and the static modulus of rock. The dynamic modulus is calculated with the ultrasonic velocity measurement, the small-cycle m...Nonlinear elastidty of the earth medium produces a numerical difference between the dynamic and the static modulus of rock. The dynamic modulus is calculated with the ultrasonic velocity measurement, the small-cycle modulus is calculated with small cycles in the load-unload experiment, the static modulus is calculated from the slope of the stress-strain curve in the large cycle, the Young＇ s modulus is obtained from the ratio of stress to strain in the measured point. The relationship between the modulus and the strain amplitudes is studied by changing the strain amplitude in the small cycles. The moduli obtained from different measuring methods are thus compared. The result shows that the dynamic modulus is the largest, the small-cycle modulus takes the second place, the static modulus of bigger-cycle is the third, and finally the Young＇s modulus is the smallest. Nonlinear modulus of rock is a function of the strain level and strain amplitude. The modulus decreases exponentially with the ascending of the strain amplitude, while increases with the ascending of the strain level. Finally, the basic concept of the P-M model is briefly introduced and the relationship between the modulus and strain amplitude is explained by the rock having different distribution densities and the different openand-close stresses of the micro-cracks.展开更多
The strain and electron energy levels of InAs/GaAs（001） quantum dots （QDs） with a GaNAs strain compensation layer （SCL） are investigated. The results show that both the hydrostatic and biaxiai strain inside the ...The strain and electron energy levels of InAs/GaAs（001） quantum dots （QDs） with a GaNAs strain compensation layer （SCL） are investigated. The results show that both the hydrostatic and biaxiai strain inside the QDs with a GaNAs SCL are reduced compared with those with GaAs capping layers. Moreover, most of the compressive strain in the growth surface is compensated by the tensile strain of the GaNAs SCL, which implies that the influence of the strain environment of underlying QDs upon the next-layer QDs＇ growth surface is weak and suggests that the homogeneity and density of QDs can be improved. Our results are consistent with the published experimental literature. A GaNAs SCL is shown to influence the strain and band edge. As is known, the strain and the band offset affect the electronic structure, which shows that the SCL is proved to be useful to tailor the emission wavelength of QDs. Our research helps to better understand how the strain compensation technology can be applied to the growth of stacked QDs, which are useful in solar cells and laser devices.展开更多
One of the principal parameters to study the tectonics deformation is the relation between the shortening axis and the direction of preexistent principal fault. It is important to verify this parameter in the belts st...One of the principal parameters to study the tectonics deformation is the relation between the shortening axis and the direction of preexistent principal fault. It is important to verify this parameter in the belts structures. The aim of this contribution is to check this notion in the Atlassic structures, especially in the southern limit of Tunisian Atlas: Gafsa fault. The strain partitioning model proposed in the interpretation of geodynamics of Gafsa chains suggests the coexistence of thrusting and strike-slip faults during the same tectonics phase. The application of this model requires a particular geometry between the shortening axis and the direction of fault, and indeed the obliquity of preexistent faults by the reported shortening axis interprets us a transpressive context. The slickenside examination shows the coexistence of thrusting and strike-slip faults. The application of model of strain partitioning requires a decollement level which is confirmed in the Gafsa basin by the upper level of Triassic series. These parameters confirm a particular relation thin and thick-skinned and the maximum of deformation is cover, although the basement structures permeate simple passive transport of the deformation along the Triassic decollement level. These problems confirm the assumption of the evolution of the shortening axis during geological events and especially the rotation of Africa and Eurasia.展开更多
基金supported by the National Natural Science Foundation of China(11972375,12211530028)the Natural Science Foundation of Shandong Province(ZR202011050038,ZR2022MA086)+1 种基金the Science and Technology Project in Qingdao Developing Zone(2020-81)Special Funds for the Basic Scientific Research Expenses of Central Government Universities(2472022X03006A).
文摘The rubber cylinder is a key component for maintaining the sealing pressure of the packer,particularly in deep underground wells.The stress relaxation of materials,as a typical feature of viscoelasticity,has become one of the main factors causing the failure of rubber cylinders in service.In the present study,a visco-hyperelastic model for the sealing rubber considering different strain levels is proposed based on the Prony series.Subsequently,the uniaxial compression stress relaxation experiments are conducted on the sealing rubber under different temperatures and strain levels,and the model parameters are thereby identified.As a case study,the proposed model is incorporated into the ABAQUS software via the UM AT subroutine,and the finite element simulation of the sealing packer is carried out.The results show that the sealing performance of the packer improves with a decrease in temperature or an increase in strain level.It is also noted that a large strain level can lead to the protrusion of the shoulder of the rubber cylinder.
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Effects of attenuated highly pathogenic pig reproductive and respiratory syndrome（HP-PRRS）TJM-F92 strain vaccine on immune antibody level against classical swine fever（CSF）and foot-and-mouth disease（FMD）were studied from October 8 to November 12 in 2014,in order to optimize vaccination program of CSF,HP-PRRS and FMD and to provide scientific guidance for animal disease control and prevention work.The results showed that attenuated HP-PRRS（TJMF92 strain）vaccine had no significant effect on immune antibody level of hog cholera lapinized virus（HCLV,ST passage cell vaccine）attenuated vaccine and FMD-O inactivated vaccines（OZK/93 strain）,and single or combined use of three vaccines received good immunization effects.
基金supported by the National Natural Science Foundation for Key Programs of China(81790632)the National Natural Science Foundation of China(31970863)the Innovation Leader Team Program of Guangzhou(201809010014)。
文摘Colorectal cancer(CRC)is the third leading cancer globally.Metagenomics has been widely used to analyze the association between the gut microbiota and CRC based on bacterial genus-or species-level comparisons,providing evidence of dysbiosis in CRC development.However,this kind of analysis is unable to provide strain-level information for understanding the individual role of a species in CRC.Here,we used culturomics to isolate CRC mucosal samples and selected 158 Escherichia coli strains to reveal their differences in both genomics and functions by means of phylogenetic analysis and inflammatory induction based on cell and animal experiments.Through genomic comparison,these strains were divided into five phylogroups.The representative strains of each phylogroup significantly induced different levels of cytokine secretion by human leukemic monocyte(THP-1 cell)-based Transwell and animal experiments.Further bioinformatic analysis revealed different profiles of single-nucleotide polymorphisms,genes,and metabolic pathways in the different phylogroups,which can improve the current understanding of the phenotypic differences between these strains.The strain differences revealed in both genomics and functions indicate that the microbiota’s function at the strain level should be investigated in order to understand the interacting mechanisms between hosts and gut bacteria.
基金The project was funded by the National Natural ScienceFoundation,China (Item No.40274057) .
文摘Nonlinear elastidty of the earth medium produces a numerical difference between the dynamic and the static modulus of rock. The dynamic modulus is calculated with the ultrasonic velocity measurement, the small-cycle modulus is calculated with small cycles in the load-unload experiment, the static modulus is calculated from the slope of the stress-strain curve in the large cycle, the Young＇ s modulus is obtained from the ratio of stress to strain in the measured point. The relationship between the modulus and the strain amplitudes is studied by changing the strain amplitude in the small cycles. The moduli obtained from different measuring methods are thus compared. The result shows that the dynamic modulus is the largest, the small-cycle modulus takes the second place, the static modulus of bigger-cycle is the third, and finally the Young＇s modulus is the smallest. Nonlinear modulus of rock is a function of the strain level and strain amplitude. The modulus decreases exponentially with the ascending of the strain amplitude, while increases with the ascending of the strain level. Finally, the basic concept of the P-M model is briefly introduced and the relationship between the modulus and strain amplitude is explained by the rock having different distribution densities and the different openand-close stresses of the micro-cracks.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60908028, 60971068, 10979065, and 61275201)the Fundamental Research Funds for the Central Universities of Ministry of Education of China (Grant No. 2011RC0402)the Program for New Century Excellent Talents in University of Ministry of Education of China (Grant No. NCET-10-0261)
文摘The strain and electron energy levels of InAs/GaAs（001） quantum dots （QDs） with a GaNAs strain compensation layer （SCL） are investigated. The results show that both the hydrostatic and biaxiai strain inside the QDs with a GaNAs SCL are reduced compared with those with GaAs capping layers. Moreover, most of the compressive strain in the growth surface is compensated by the tensile strain of the GaNAs SCL, which implies that the influence of the strain environment of underlying QDs upon the next-layer QDs＇ growth surface is weak and suggests that the homogeneity and density of QDs can be improved. Our results are consistent with the published experimental literature. A GaNAs SCL is shown to influence the strain and band edge. As is known, the strain and the band offset affect the electronic structure, which shows that the SCL is proved to be useful to tailor the emission wavelength of QDs. Our research helps to better understand how the strain compensation technology can be applied to the growth of stacked QDs, which are useful in solar cells and laser devices.
文摘One of the principal parameters to study the tectonics deformation is the relation between the shortening axis and the direction of preexistent principal fault. It is important to verify this parameter in the belts structures. The aim of this contribution is to check this notion in the Atlassic structures, especially in the southern limit of Tunisian Atlas: Gafsa fault. The strain partitioning model proposed in the interpretation of geodynamics of Gafsa chains suggests the coexistence of thrusting and strike-slip faults during the same tectonics phase. The application of this model requires a particular geometry between the shortening axis and the direction of fault, and indeed the obliquity of preexistent faults by the reported shortening axis interprets us a transpressive context. The slickenside examination shows the coexistence of thrusting and strike-slip faults. The application of model of strain partitioning requires a decollement level which is confirmed in the Gafsa basin by the upper level of Triassic series. These parameters confirm a particular relation thin and thick-skinned and the maximum of deformation is cover, although the basement structures permeate simple passive transport of the deformation along the Triassic decollement level. These problems confirm the assumption of the evolution of the shortening axis during geological events and especially the rotation of Africa and Eurasia.
