Identifying the stiffness and damping of active magnetic bearings(AMBs)is necessary since those parameters can affect the stability and performance of the high-speed rotor AMBs system.A new identification method is pr...Identifying the stiffness and damping of active magnetic bearings(AMBs)is necessary since those parameters can affect the stability and performance of the high-speed rotor AMBs system.A new identification method is proposed to identify the stiffness and damping coefficients of a rotor AMB system.This method combines the global optimization capability of the genetic algorithm(GA)and the local search ability of Nelder-Mead simplex method.The supporting parameters are obtained using the hybrid GA based on the experimental unbalance response calculated through the transfer matrix method.To verify the identified results,the experimental stiffness and damping coefficients are employed to simulate the unbalance responses for the rotor AMBs system using the finite element method.The close agreement between the simulation and experimental data indicates that the proposed identified algorithm can effectively identify the AMBs supporting parameters.展开更多
The emission lines of B,C,O and Fe in tokamak plasma are reported.The spectra are compared with those calculated by the CHIANTI code,which is based on the collisional-radiative models with a large amount of accurate a...The emission lines of B,C,O and Fe in tokamak plasma are reported.The spectra are compared with those calculated by the CHIANTI code,which is based on the collisional-radiative models with a large amount of accurate atomic data.General agreement is obtained between the results of experiment and computation.Most of the lines in the spectra are identified,and the relative number density ratios of B,C,O and Fe are determined.It is found that the processes of line formation in our experiment are similar to those in the stellar coronae.The line-averaged electron density of the tokamak plasma is measured by the HCN laser,indicating a good agreement with the theoretical prediction by the density-dependent line ratio of Fe XXI.展开更多
At present,there is less theoretical research and practical experience in the aspect of ultrashallow seismic exploration to the target layers at depths of only tens of meters both at home and abroad. Seismic explorati...At present,there is less theoretical research and practical experience in the aspect of ultrashallow seismic exploration to the target layers at depths of only tens of meters both at home and abroad. Seismic exploration plays an important role in the location of faults and active structures,but the depth dozens of meters below the ground surface is the blind area of any kind of deep and shallow seismic exploration. Starting from the point of view of detecting urban active faults,and using related theories and methods of geology,geophysics and mathematics,the paper discusses the preconditions for acquiring efficient ultra-shallow seismic survey results in complicated geological backgrounds in Qingdao.Taking the Qingdao area as an example in this paper,we study the depth condition of Quaternary deposits,and apply 4-8 stacking folds to satisfy the requirement to get the exploration results with high-resolution and high-SNR. Preliminary results reveal that selecting a proper surveillance layout is one of the keys to acquire authentic exploration results in ultra-shallow P-wave reflection exploration. Our results also show that ultrashallow seismic reflection method in detecting faults in the Qingdao area has good application prospects.展开更多
Absent in melanoma 2(AIM2)has been reported to be a component of inflammasomes in innate immune cells.Surprisingly,AIM2 is expressed by B cells,and higher AIM2 expression is observed in the B cells from lupus patients...Absent in melanoma 2(AIM2)has been reported to be a component of inflammasomes in innate immune cells.Surprisingly,AIM2 is expressed by B cells,and higher AIM2 expression is observed in the B cells from lupus patients.To date,the inflammasome-indepe ndent functi on of AIM2 in B cells remai ns un clear.Here,we report in creased expressi on of AIM2 in human tonsil memory and germinal center(GC)B cells and in memory B cells and plasma cells from the circulation and skin lesions of lupus patients.Conditional knockout of AIM2 in B cells reduces the CD19^(+)B-cell frequency in lymph nodes and spleens,and dampens KLH-induced lgG1-antibody production.In a pristane-induced mouse model of lupus,AIM2 deficiency in B cells attenuates lupus symptoms and reduces the frequency of GC B cells,T follicular helper(Tfh)cells,plasmablast cells,and plasma cells.Furthermore,the loss of AIM2 in human B cells leads to the increased expression of Blimp-1 and reduces the expression of Bcl-6.However,the silendng of Blimp-1 and Bcl-6 has no significant effect on AIM2 expression,indicating that AIM2 might be the upstream regulator for Blimp-1 and Bcl-6.In addition,IL-10 is found to upregulate AIM2 expression via DNA demethylation.Together,our findings reveal that AIM2 is highly expressed in the B cells of lupus patients and promotes B-cell differentiation by modulating the Bcl-6-Blimp-1 axis,providing a novel target for SLE treatment.展开更多
B cells have a critical role in the initiation and acceleration of autoimmune diseases, especially those mediated byautoantibodies. In the peripheral lymphoid system, mature B cells are activated by self or/and foreig...B cells have a critical role in the initiation and acceleration of autoimmune diseases, especially those mediated byautoantibodies. In the peripheral lymphoid system, mature B cells are activated by self or/and foreign antigens andsignals from helper T cells for differentiating into either memory B cells or antibody-producing plasma cells.Accumulating evidence has shown that epigenetic regulations modulate somatic hypermutation and class switchDNA recombination during B-cell activation and differentiation. Any abnormalities in these complex regulatoryprocesses may contribute to aberrant antibody production, resulting in autoimmune pathogenesis such as systemiclupus erythematosus. Newly generated knowledge from advanced modern technologies such as next-generationsequencing, single-cell sequencing and DNA methylation sequencing has enabled us to better understand B-cellbiology and its role in autoimmune development. Thus this review aims to summarize current research progress inepigenetic modifications contributing to B-cell activation and differentiation, especially under autoimmuneconditions such as lupus, rheumatoid arthritis and type 1 diabetes.展开更多
Lake ice thickness(LIT)is important for regional hydroclimate systems,lake ecosystems,and human activities on the ice,and is thought to be highly susceptible to global warming.However,the spatiotemporal variability in...Lake ice thickness(LIT)is important for regional hydroclimate systems,lake ecosystems,and human activities on the ice,and is thought to be highly susceptible to global warming.However,the spatiotemporal variability in LIT is largely unknown due to the difficulty in deriving in situ measurements and the lack of an effective remote sensing platform.Despite intensive development and applications of lake ice models driven by general circulation model output,evaluation of the global LIT is mostly based on assumed“ideal”lakes in each grid cell of the climate forcing data.A method for calculating the actual global LIT is therefore urgently needed.Here we use satellite altimetry to retrieve ice thickness for 16 large lakes in the Northern Hemisphere(Lake Baikal,Great Slave Lake,and others)with an accuracy of~0.2 m for almost three decades.We then develop a 1-D lake ice model driven primarily by remotely sensed data and cross-validated with the altimetric LIT to provide a robust means of estimating LIT for lakes larger than 50 km^(2)across the Northern Hemisphere.Mean LIT(annual maximum ice thickness)for 1313 simulated lakes and reservoirs covering~840,000 km^(2)for 2003–2018 is 0.63±0.02 m,corresponding to~485 Gt of water.LIT changes are projected for 2071–2099 under RCPs 2.6,6.0,and 8.5,showing that the mean LIT could decrease by~0.35 m under the worst concentration pathway and the associated lower ice road availability could have a significant impact on socio-economic activities.展开更多
基金supported by the National Natural Science Foundation of China(No.51675261)Jiangsu Province Key R & D Programs(No.BE2016180)
文摘Identifying the stiffness and damping of active magnetic bearings(AMBs)is necessary since those parameters can affect the stability and performance of the high-speed rotor AMBs system.A new identification method is proposed to identify the stiffness and damping coefficients of a rotor AMB system.This method combines the global optimization capability of the genetic algorithm(GA)and the local search ability of Nelder-Mead simplex method.The supporting parameters are obtained using the hybrid GA based on the experimental unbalance response calculated through the transfer matrix method.To verify the identified results,the experimental stiffness and damping coefficients are employed to simulate the unbalance responses for the rotor AMBs system using the finite element method.The close agreement between the simulation and experimental data indicates that the proposed identified algorithm can effectively identify the AMBs supporting parameters.
基金by the National Natural Science Foundation of China under Grant Nos 10821061,10876040,10925421 and 10734130the Chinese Academy of Sciences under Grant No KJCX2-YW-T01the National Basic Research Program of China under Grant No 2007CB815103.
文摘The emission lines of B,C,O and Fe in tokamak plasma are reported.The spectra are compared with those calculated by the CHIANTI code,which is based on the collisional-radiative models with a large amount of accurate atomic data.General agreement is obtained between the results of experiment and computation.Most of the lines in the spectra are identified,and the relative number density ratios of B,C,O and Fe are determined.It is found that the processes of line formation in our experiment are similar to those in the stellar coronae.The line-averaged electron density of the tokamak plasma is measured by the HCN laser,indicating a good agreement with the theoretical prediction by the density-dependent line ratio of Fe XXI.
基金sponsored by the PhD Research Foundation of Hebei GEO University(BQ2017027)
文摘At present,there is less theoretical research and practical experience in the aspect of ultrashallow seismic exploration to the target layers at depths of only tens of meters both at home and abroad. Seismic exploration plays an important role in the location of faults and active structures,but the depth dozens of meters below the ground surface is the blind area of any kind of deep and shallow seismic exploration. Starting from the point of view of detecting urban active faults,and using related theories and methods of geology,geophysics and mathematics,the paper discusses the preconditions for acquiring efficient ultra-shallow seismic survey results in complicated geological backgrounds in Qingdao.Taking the Qingdao area as an example in this paper,we study the depth condition of Quaternary deposits,and apply 4-8 stacking folds to satisfy the requirement to get the exploration results with high-resolution and high-SNR. Preliminary results reveal that selecting a proper surveillance layout is one of the keys to acquire authentic exploration results in ultra-shallow P-wave reflection exploration. Our results also show that ultrashallow seismic reflection method in detecting faults in the Qingdao area has good application prospects.
基金supported by the National Natural Science Foundation of China(Nos.81972943,81830097)Hunan Talent Young Investigator(No.2019RS2012)+1 种基金Hunan Outstanding Young Investigator(No.2O2OJJ2O55)CAMS Innovation Fund for Medical Sciences(CIFMS)(2019-I2M-5-033)Chongqing International Institute for Immunology(2020YJC10).
文摘Absent in melanoma 2(AIM2)has been reported to be a component of inflammasomes in innate immune cells.Surprisingly,AIM2 is expressed by B cells,and higher AIM2 expression is observed in the B cells from lupus patients.To date,the inflammasome-indepe ndent functi on of AIM2 in B cells remai ns un clear.Here,we report in creased expressi on of AIM2 in human tonsil memory and germinal center(GC)B cells and in memory B cells and plasma cells from the circulation and skin lesions of lupus patients.Conditional knockout of AIM2 in B cells reduces the CD19^(+)B-cell frequency in lymph nodes and spleens,and dampens KLH-induced lgG1-antibody production.In a pristane-induced mouse model of lupus,AIM2 deficiency in B cells attenuates lupus symptoms and reduces the frequency of GC B cells,T follicular helper(Tfh)cells,plasmablast cells,and plasma cells.Furthermore,the loss of AIM2 in human B cells leads to the increased expression of Blimp-1 and reduces the expression of Bcl-6.However,the silendng of Blimp-1 and Bcl-6 has no significant effect on AIM2 expression,indicating that AIM2 might be the upstream regulator for Blimp-1 and Bcl-6.In addition,IL-10 is found to upregulate AIM2 expression via DNA demethylation.Together,our findings reveal that AIM2 is highly expressed in the B cells of lupus patients and promotes B-cell differentiation by modulating the Bcl-6-Blimp-1 axis,providing a novel target for SLE treatment.
基金This work was supported by the National Natural Science Foundation of China(Nos.81220108017,81522038,81602767,81430074,91442116,81373195 and 81771761)National Basic Research Program of China(No.2014CB541904)+2 种基金the Programs of Science-Technology Commission of Hunan Province(2013F J4202)the Natural Science Foundation of Hunan Province(2017JJ3453)the Natural Key Clinical Speciality Construction Project of National Health and Family Planning Commission of the People’s Republic of China.
文摘B cells have a critical role in the initiation and acceleration of autoimmune diseases, especially those mediated byautoantibodies. In the peripheral lymphoid system, mature B cells are activated by self or/and foreign antigens andsignals from helper T cells for differentiating into either memory B cells or antibody-producing plasma cells.Accumulating evidence has shown that epigenetic regulations modulate somatic hypermutation and class switchDNA recombination during B-cell activation and differentiation. Any abnormalities in these complex regulatoryprocesses may contribute to aberrant antibody production, resulting in autoimmune pathogenesis such as systemiclupus erythematosus. Newly generated knowledge from advanced modern technologies such as next-generationsequencing, single-cell sequencing and DNA methylation sequencing has enabled us to better understand B-cellbiology and its role in autoimmune development. Thus this review aims to summarize current research progress inepigenetic modifications contributing to B-cell activation and differentiation, especially under autoimmuneconditions such as lupus, rheumatoid arthritis and type 1 diabetes.
基金supported by the National Natural Science Foundation of China(92047301,91547210,and 51722903)the Second Tibetan Plateau Scientific Expedition and Research(STEP)Program(2019QZKK0105)。
文摘Lake ice thickness(LIT)is important for regional hydroclimate systems,lake ecosystems,and human activities on the ice,and is thought to be highly susceptible to global warming.However,the spatiotemporal variability in LIT is largely unknown due to the difficulty in deriving in situ measurements and the lack of an effective remote sensing platform.Despite intensive development and applications of lake ice models driven by general circulation model output,evaluation of the global LIT is mostly based on assumed“ideal”lakes in each grid cell of the climate forcing data.A method for calculating the actual global LIT is therefore urgently needed.Here we use satellite altimetry to retrieve ice thickness for 16 large lakes in the Northern Hemisphere(Lake Baikal,Great Slave Lake,and others)with an accuracy of~0.2 m for almost three decades.We then develop a 1-D lake ice model driven primarily by remotely sensed data and cross-validated with the altimetric LIT to provide a robust means of estimating LIT for lakes larger than 50 km^(2)across the Northern Hemisphere.Mean LIT(annual maximum ice thickness)for 1313 simulated lakes and reservoirs covering~840,000 km^(2)for 2003–2018 is 0.63±0.02 m,corresponding to~485 Gt of water.LIT changes are projected for 2071–2099 under RCPs 2.6,6.0,and 8.5,showing that the mean LIT could decrease by~0.35 m under the worst concentration pathway and the associated lower ice road availability could have a significant impact on socio-economic activities.
