Antarctic coastal polynyas are biological hotspots in the Southern Ocean that support the abundance of hightrophic-level predators and are important for carbon cycling in the high-latitude oceans.In this study,we exam...Antarctic coastal polynyas are biological hotspots in the Southern Ocean that support the abundance of hightrophic-level predators and are important for carbon cycling in the high-latitude oceans.In this study,we examined the interannual variation of summertime phytoplankton biomass in the Marguerite Bay polynya(MBP)in the western Antarctic Peninsula area,and linked such variability to the Southern Annular Mode(SAM)that dominated the southern hemisphere extratropical climate variability.Combining satellite data,atmosphere reanalysis products and numerical simulations,we found that the interannual variation of summer chlorophyll-a(Chl-a)concentration in the MBP is significantly and negatively correlated with the spring SAM index,and weakly correlated with the summer SAM index.The negative relation between summer Chl-a and spring SAM is due to weaker spring vertical mixing under a more positive SAM condition,which would inhibit the supply of iron from deep layers into the surface euphotic layer.The negative relation between spring mixing and spring SAM results from greater precipitation rate over the MBP region in positive SAM phase,which leads to lower salinity in the ocean surface layer.The coupled physical-biological mechanisms between SAM and phytoplankton biomass revealed in this study is important for us to predict the future variations of phytoplankton biomasses in Antarctic polynyas under climate change.展开更多
Nowadays,having an effective technique in preparing semi-solid slurries for rheocasting process seems to be an essential requirement.In this study,semi-solid slurry of A356 aluminum alloy was prepared by three-phase a...Nowadays,having an effective technique in preparing semi-solid slurries for rheocasting process seems to be an essential requirement.In this study,semi-solid slurry of A356 aluminum alloy was prepared by three-phase annular electromagnetic stirring(A-EMS)technique under different conditions.The effects of stirring current,pouring temperature and stirring time on microstructural evolution,mean particle size,shape factor and solid fraction were investigated.The rheocasting process was carried out by using a drop weight setup and to inject the prepared semi-solid slurry in optimal conditions into the step-die cavity.The filling behavior and mechanical properties of parts were studied.Microstructural evolution showed that the best semi-solid slurry which had fine spherical particles with the average size of~27μm and a shape factor of~0.8 was achieved at the stirring current of 70 A,melt pouring temperature of 670℃,and stirring time of 30 s.Under these conditions,the step-die cavity was completely filled at die preheating temperature of 470℃.The hardness increases by decreasing step thickness as well as die preheating temperature.Moreover,the tensile properties are improved at lower die preheating temperatures.The fracture surface,which consists of a complex topography,indicates a typical ductile fracture.展开更多
Mass transfer performance of gas–liquid two-phase flow at microscale is the basis of application of microreactor in gas–liquid reaction systems.At present,few researches on the mass transfer property of annular flow...Mass transfer performance of gas–liquid two-phase flow at microscale is the basis of application of microreactor in gas–liquid reaction systems.At present,few researches on the mass transfer property of annular flow have been reported.Therefore,the mass transfer mechanism and relationship of gas–liquid annular flow in a microfluidic cross-junction device are studied in the present study.We find that the main factors,i.e.,flow pattern,liquid film thickness,liquid hydraulic retention time,phase interface fluctuation,and gas flow vorticity,which influence the flow mass transfer property,are directly affected both by gas and liquid flow velocities.But the influences of gas and liquid velocities on different mass transfer influencing factors are different.Thereout,the fitting relationships between gas and liquid flow velocities and mass transfer influencing factors are established.By comparing the results from calculations using fitting equations and simulations,it shows that the fitting equations have relatively high degrees of accuracy.Finally,the Pareto front,namely the Pareto optimal solution set,of gas and liquid velocity conditions for the best flow mass transfer property is obtained using the method of multi-objective particle swarm optimization.It is proved that the mass transfer property of the gas–liquid two-phase flow can be obviously enhanced under the guidance of the obtained Pareto optimal solution set through experimental verification.展开更多
BACKGROUND Granuloma annulare(GA)has diverse clinical manifestations,multiple subtypes,and unknown etiology and pathogenesis.Existing studies regarding GA in children are scarce.AIM To examine the correlation between ...BACKGROUND Granuloma annulare(GA)has diverse clinical manifestations,multiple subtypes,and unknown etiology and pathogenesis.Existing studies regarding GA in children are scarce.AIM To examine the correlation between clinical manifestation and histopathology of pediatric GA.METHODS A total of 39 patients under 18 years of age with both a clinical and pathological diagnosis of GA at Kunming Children's Hospital from 2017 to 2022 were retrieved.Their medical records were consulted,and clinical data of the children were recorded and summarized,including gender,age,disease site,etc.Existing wax blocks of skin lesion specimens of children and pathological films were retrieved for further study and relevant histology,including hematoxylin-eosin,Alcian blue,elastic fiber(Victoria blue-Lichon red method),and antacid staining.Finally,the children’s clinical manifestations,histopathological results,and special staining characteristics were analyzed.RESULTS The clinical manifestations of granuloma annulare in children were diverse:11 cases presented with a single lesion,25 with multiple lesions,and 3 with generalized lesions.The pathological typing comprised histiocytic infiltration,palisading granuloma,epithelioid nodular,and mixed types in 4,11,9,and 15 cases,respectively.Thirty-nine cases were negative for antacid staining.The positive rate of Alcian blue staining was 92.3%,and that of elastic fiber staining was 100%.The degree of elastic fiber dissolution and granuloma annulare histopathological typing were positively correlated(r=0.432,P<0.05).No correlation was found between clinical presentation and histopathological typing of the granuloma annulare in children.In the pathological diagnosis of granuloma annulare,the positive elastic fiber staining rate was higher than that of Alcian blue staining.A correlation was found between elastic fiber dissolution degree and histopathological staging.However,the differences in pathological staging may have been related to the pathological manifestation of granuloma annulare at different periods.CONCLUSION Elastic fiber degradation may be a critical step in the pathogenesis of pediatric granuloma annulare.This is also one of the first studies focused on granuloma annulare in children.展开更多
BACKGROUND Granuloma annulare(GA)has diverse clinical manifestations including papules,plaques,and nodules on the extremities that are skin-colored,pink,or purple.Approximately 15%of all GA cases are considered genera...BACKGROUND Granuloma annulare(GA)has diverse clinical manifestations including papules,plaques,and nodules on the extremities that are skin-colored,pink,or purple.Approximately 15%of all GA cases are considered generalized GA.CASE SUMMARY Herein,we describe the case of a pediatric patient who initially presented with papules and later developed generalized atrophic macules.Upon examination,two different morphologic lesions were histopathologically confirmed:Epithelioid nodular GA and scattered histiocytic infiltrative GA.This patient exhibited rare clinical manifestations that differed throughout the course of the disease.The varying histopathological types and clinical manifestations of GA may be linked to the different stages of the disease.CONCLUSION This rare case demonstrates the different histopathological features of different stages and clinical manifestations of granuloma annulare in an infant.展开更多
This work presents an optimal design method of antenna aperture illumination for microwave power transmission with an annular collection area.The objective is to maximize the ratio of the power radiated on the annular...This work presents an optimal design method of antenna aperture illumination for microwave power transmission with an annular collection area.The objective is to maximize the ratio of the power radiated on the annular collection area to the total transmitted power.By formulating the aperture amplitude distribution through a summation of a special set of series,the optimal design problem can be reduced to finding the maximum ratio of two real quadratic forms.Based on the theory of matrices,the solution to the formulated optimization problem is to determine the largest characteristic value and its associated characteristic vector.To meet security requirements,the peak radiation levels outside the receiving area are considered to be extra constraints.A hybrid grey wolf optimizer and Nelder–Mead simplex method is developed to deal with this constrained optimization problem.In order to demonstrate the effectiveness of the proposed method,numerical experiments on continuous apertures are conducted;then,discrete arrays of isotropic elements are employed to validate the correctness of the optimized results.Finally,patch arrays are adopted to further verify the validity of the proposed method.展开更多
基金The Key Research&Development Program of the Ministry of Science and Technology of China under contract No.2022YFC2807601the National Natural Science Foundation of China under contract Nos 41941008 and 41876221+3 种基金the Fund of Shanghai Science and Technology Committee under contract Nos 20230711100 and 21QA1404300the Impact and Response of Antarctic Seas to Climate Change funded by the Chinese Arctic and Antarctic Administration under contract No.IRASCC 1-02-01Bthe National Key Research and Development Program of China under contract No.2019YFC1509102the Shanghai Pilot Program for Basic Research—Shanghai Jiao Tong University under contract No.21TQ1400201。
文摘Antarctic coastal polynyas are biological hotspots in the Southern Ocean that support the abundance of hightrophic-level predators and are important for carbon cycling in the high-latitude oceans.In this study,we examined the interannual variation of summertime phytoplankton biomass in the Marguerite Bay polynya(MBP)in the western Antarctic Peninsula area,and linked such variability to the Southern Annular Mode(SAM)that dominated the southern hemisphere extratropical climate variability.Combining satellite data,atmosphere reanalysis products and numerical simulations,we found that the interannual variation of summer chlorophyll-a(Chl-a)concentration in the MBP is significantly and negatively correlated with the spring SAM index,and weakly correlated with the summer SAM index.The negative relation between summer Chl-a and spring SAM is due to weaker spring vertical mixing under a more positive SAM condition,which would inhibit the supply of iron from deep layers into the surface euphotic layer.The negative relation between spring mixing and spring SAM results from greater precipitation rate over the MBP region in positive SAM phase,which leads to lower salinity in the ocean surface layer.The coupled physical-biological mechanisms between SAM and phytoplankton biomass revealed in this study is important for us to predict the future variations of phytoplankton biomasses in Antarctic polynyas under climate change.
基金supported by the National Key Research and Development Project[grant number 2020YFA0608902]the Natural Science Foundation of Guangdong Province[grant number 2023A1515010889].
基金Central Applied Research Laboratory(CARL)Center of Materials ResearchDepartment of Materials Science and Metallurgy,Shahid Bahonar University of Kerman(SBUK)for support of this work。
文摘Nowadays,having an effective technique in preparing semi-solid slurries for rheocasting process seems to be an essential requirement.In this study,semi-solid slurry of A356 aluminum alloy was prepared by three-phase annular electromagnetic stirring(A-EMS)technique under different conditions.The effects of stirring current,pouring temperature and stirring time on microstructural evolution,mean particle size,shape factor and solid fraction were investigated.The rheocasting process was carried out by using a drop weight setup and to inject the prepared semi-solid slurry in optimal conditions into the step-die cavity.The filling behavior and mechanical properties of parts were studied.Microstructural evolution showed that the best semi-solid slurry which had fine spherical particles with the average size of~27μm and a shape factor of~0.8 was achieved at the stirring current of 70 A,melt pouring temperature of 670℃,and stirring time of 30 s.Under these conditions,the step-die cavity was completely filled at die preheating temperature of 470℃.The hardness increases by decreasing step thickness as well as die preheating temperature.Moreover,the tensile properties are improved at lower die preheating temperatures.The fracture surface,which consists of a complex topography,indicates a typical ductile fracture.
基金the National Natural Science Foundation of China(22178241,21908152 and 21978189)State Key Laboratory of Chemical Engineering,China(SKL-ChE-21A01).
文摘Mass transfer performance of gas–liquid two-phase flow at microscale is the basis of application of microreactor in gas–liquid reaction systems.At present,few researches on the mass transfer property of annular flow have been reported.Therefore,the mass transfer mechanism and relationship of gas–liquid annular flow in a microfluidic cross-junction device are studied in the present study.We find that the main factors,i.e.,flow pattern,liquid film thickness,liquid hydraulic retention time,phase interface fluctuation,and gas flow vorticity,which influence the flow mass transfer property,are directly affected both by gas and liquid flow velocities.But the influences of gas and liquid velocities on different mass transfer influencing factors are different.Thereout,the fitting relationships between gas and liquid flow velocities and mass transfer influencing factors are established.By comparing the results from calculations using fitting equations and simulations,it shows that the fitting equations have relatively high degrees of accuracy.Finally,the Pareto front,namely the Pareto optimal solution set,of gas and liquid velocity conditions for the best flow mass transfer property is obtained using the method of multi-objective particle swarm optimization.It is proved that the mass transfer property of the gas–liquid two-phase flow can be obviously enhanced under the guidance of the obtained Pareto optimal solution set through experimental verification.
基金Supported by Spring City Project Famous Doctor Special
文摘BACKGROUND Granuloma annulare(GA)has diverse clinical manifestations,multiple subtypes,and unknown etiology and pathogenesis.Existing studies regarding GA in children are scarce.AIM To examine the correlation between clinical manifestation and histopathology of pediatric GA.METHODS A total of 39 patients under 18 years of age with both a clinical and pathological diagnosis of GA at Kunming Children's Hospital from 2017 to 2022 were retrieved.Their medical records were consulted,and clinical data of the children were recorded and summarized,including gender,age,disease site,etc.Existing wax blocks of skin lesion specimens of children and pathological films were retrieved for further study and relevant histology,including hematoxylin-eosin,Alcian blue,elastic fiber(Victoria blue-Lichon red method),and antacid staining.Finally,the children’s clinical manifestations,histopathological results,and special staining characteristics were analyzed.RESULTS The clinical manifestations of granuloma annulare in children were diverse:11 cases presented with a single lesion,25 with multiple lesions,and 3 with generalized lesions.The pathological typing comprised histiocytic infiltration,palisading granuloma,epithelioid nodular,and mixed types in 4,11,9,and 15 cases,respectively.Thirty-nine cases were negative for antacid staining.The positive rate of Alcian blue staining was 92.3%,and that of elastic fiber staining was 100%.The degree of elastic fiber dissolution and granuloma annulare histopathological typing were positively correlated(r=0.432,P<0.05).No correlation was found between clinical presentation and histopathological typing of the granuloma annulare in children.In the pathological diagnosis of granuloma annulare,the positive elastic fiber staining rate was higher than that of Alcian blue staining.A correlation was found between elastic fiber dissolution degree and histopathological staging.However,the differences in pathological staging may have been related to the pathological manifestation of granuloma annulare at different periods.CONCLUSION Elastic fiber degradation may be a critical step in the pathogenesis of pediatric granuloma annulare.This is also one of the first studies focused on granuloma annulare in children.
文摘BACKGROUND Granuloma annulare(GA)has diverse clinical manifestations including papules,plaques,and nodules on the extremities that are skin-colored,pink,or purple.Approximately 15%of all GA cases are considered generalized GA.CASE SUMMARY Herein,we describe the case of a pediatric patient who initially presented with papules and later developed generalized atrophic macules.Upon examination,two different morphologic lesions were histopathologically confirmed:Epithelioid nodular GA and scattered histiocytic infiltrative GA.This patient exhibited rare clinical manifestations that differed throughout the course of the disease.The varying histopathological types and clinical manifestations of GA may be linked to the different stages of the disease.CONCLUSION This rare case demonstrates the different histopathological features of different stages and clinical manifestations of granuloma annulare in an infant.
基金supported in part by the National Key Research and Development Program of China(2021YFB3900300)in part by the National Natural Science Foundation of China(62201416)+2 种基金in part by the Fundamental Research Funds for the Central Universities(QTZX23070)in part by the Qin Chuang Yuan High-Level Innovative and Entrepreneurial Talents Project(QCYRCXM-2022-314)in part by Singapore Ministry of Education Academic Research Fund Tier 1。
文摘This work presents an optimal design method of antenna aperture illumination for microwave power transmission with an annular collection area.The objective is to maximize the ratio of the power radiated on the annular collection area to the total transmitted power.By formulating the aperture amplitude distribution through a summation of a special set of series,the optimal design problem can be reduced to finding the maximum ratio of two real quadratic forms.Based on the theory of matrices,the solution to the formulated optimization problem is to determine the largest characteristic value and its associated characteristic vector.To meet security requirements,the peak radiation levels outside the receiving area are considered to be extra constraints.A hybrid grey wolf optimizer and Nelder–Mead simplex method is developed to deal with this constrained optimization problem.In order to demonstrate the effectiveness of the proposed method,numerical experiments on continuous apertures are conducted;then,discrete arrays of isotropic elements are employed to validate the correctness of the optimized results.Finally,patch arrays are adopted to further verify the validity of the proposed method.
