Dispersion parameter is an important parameter for the establishment of groundwater solute transport model.The dispersion test uses sodium chloride as a tracer,which was conducted in a site in Jilin City.The standard ...Dispersion parameter is an important parameter for the establishment of groundwater solute transport model.The dispersion test uses sodium chloride as a tracer,which was conducted in a site in Jilin City.The standard curve comparison method was used to solve the dispersion parameters of the aquifer under the natural flow field.The test results show that under the natural flow field,the longitudinal dispersion of unconfined aquifer in Jilin City is 0.400m,and the transverse dispersion is 1.933×10-5~6.557×10-3m;while the longitudinal dispersion coefficient is 0.246m2/d,the transverse dispersion coefficient is 1.191×10-5~4.039×10-3m2/d.The above results can provide an important parameter basis for the establishment of groundwater solute transport model,the accurate prediction of temporal and spatial variation of pollutant concentration in groundwater and the formulation of groundwater pollution prevention and control scheme.展开更多
The accurate identification,detection,and segmentation of tea buds and leaves are important factors for realizing intelligent tea picking.A tea picking point location method based on the region-based convolutional neu...The accurate identification,detection,and segmentation of tea buds and leaves are important factors for realizing intelligent tea picking.A tea picking point location method based on the region-based convolutional neural network(R-CNN)Mask-RCNN is proposed,and a tea bud and leaf and picking point recognition model is established.First,tea buds and leaf pictures are collected in a complex environment,the Resnet50 residual network and a feature pyramid network(FPN)are used to extract bud and leaf features,and preliminary classification and preselection box regression training-performed on the feature maps through a regional proposal network(RPN).Second,the regional feature aggregation method(RoIAlign)is used to eliminate the quantization error,and the feature map of the preselected region of interest(ROI)is converted into a fixed-size feature map.The output module of the model realizes the functions of classification,regression and segmentation.Finally,through the output mask image and the positioning algorithm the positioning of the picking points of tea buds and leaves is determined.One hundred tea tree bud and leaf pictures in a complex environment are selected for testing.The experimental results show that the average detection accuracy rate reaches 93.95%and that the recall rate reaches 92.48%.The tea picking location method presented in this paper is more versatile and robust in complex environments.展开更多
Background:Heatwave events occur more frequently,accompanied by a significant increase in the ambient concentration of fine particulate matter(PM 2.5).Epidemiological and experimental studies have suggested that heat ...Background:Heatwave events occur more frequently,accompanied by a significant increase in the ambient concentration of fine particulate matter(PM 2.5).Epidemiological and experimental studies have suggested that heat stress or PM 2.5 exposure would impair glucose homeostasis and insulin sensitivity.Objective:To explore the joint effects of heat stress and PM 2.5 exposure on glucose metabolism and hepatic insulin pathway.Methods:C57BL/6 mice were randomly divided into filtered air(FA)group,fine particulate matter(PM)group,filtered air combined with heat stress(FH)group,and PM combined with heat stress(PH)group.Mice were exposed to PM for a total of 6 weeks,and heat stress combined with PM exposure was applied at the 5th and 6th weeks via a whole-body exposure system.Systemic glucose homeostasis,insulin sensitivity,and circulating inflammatory cytokines were examined.HSP72 expression and insulin signaling in the liver were measured.Results:Glucose tolerance and insulin sensitivity were impaired in response to heat stress,accompanied by less-ened hepatic GLUT2 expression and inhibited insulin signaling pathway.No synergistic effects of heat stress and PM 2.5 exposure on glucose homeostasis were observed,while heat-upregulated HSP72 expression was attenuated with accumulated TNF𝛼induced by further PM 2.5 exposure.Conclusion:Heat stress combined with PM 2.5 exposure induced TNF𝛼,which could inhibit heat-elevated hepatic HSP72 expression.Elevated circulating TNF𝛼impaired hepatic insulin signaling and GLUT2 expression.Then,glucose homeostasis was perturbed,and insulin action was impaired.展开更多
OBJECTIVE: Apply spectral clustering to analyze the patterns of symptoms in patients with chronic gastritis(CG).METHODS: Based on 919 CG subjects, we applied mutual information feature selection to choose the positive...OBJECTIVE: Apply spectral clustering to analyze the patterns of symptoms in patients with chronic gastritis(CG).METHODS: Based on 919 CG subjects, we applied mutual information feature selection to choose the positively correlated symptoms with each pattern.Then, we used the Shi and Malik spectral clustering algorithm to select the top 20 correlated symptoms.RESULTS: We ascertained the results of six patterns.There were three categories for the pattern of accumulation of damp heat in the spleen-stomach(0.00332). There were six categories for the pattern of dampness obstructing the spleen-stomach(0.02466). There were two categories for the pattern of spleen-stomach Qi deficiency(0.013 89).There were three categories for the pattern of spleen-stomach deficiency cold(0.009 15). There were five categories for the pattern of liver-Qistagnation(0.01910).There were four categories for the pattern of stagnant heat in the liver-stomach(0.00585).CONCLUSION: Most of the spectral clustering results of the symptoms of CG patterns were in accordance with clinical experience and Traditional Chinese Medicine theory. Most categories suggested the nature and/or location of the disease.展开更多
The platinum nanowires have been verified to be a promising catalyst to promote the performance of proton exchange membrane fuel cells.In this paper,accurately controlled growth of nanowires in a carbon matrix is achi...The platinum nanowires have been verified to be a promising catalyst to promote the performance of proton exchange membrane fuel cells.In this paper,accurately controlled growth of nanowires in a carbon matrix is achieved for reducing Pt loading.The effects of formic acid concentration and reaction temperature on the morphology and size of the Pt nanowires,as well as their electrochemical performances in a single cell,are investigated.The results showed that the increase in the formic acid concentration results in a volcano trend with the length of Pt nanowires.With increasing reduction temperature,the diameter of Pt nanowires increases while Pt particles evolve from one-dimensional to zero-dimensional up to 40°C.A mechanism of the Pt nanowires growth is proposed.The optimized Pt nanowires electrode exhibits a power density(based on electrochemical active surface area)79%higher than conventional Pt/C one.The control strategy obtained contributes to the design and control of novel nanostructures in nano-synthesis and catalyst applications.展开更多
An advanced cathode design can improve the power performance and durability of proton exchange membrane fuel cells(PEMFCs),thus reducing the stack cost of fuel cell vehicles(FCVs).Recent studies on highly active Pt al...An advanced cathode design can improve the power performance and durability of proton exchange membrane fuel cells(PEMFCs),thus reducing the stack cost of fuel cell vehicles(FCVs).Recent studies on highly active Pt alloy catalysts,short-side-chain polyfluorinated sulfonic acid(PFSA)ionomer and 3D-ordered electrodes have imparted PEMFCs with boosted power density.To achieve the compacted stack target of 6 kW/L or above for the wide commercialization of FCVs,developing available cathodes for high-power-density operation is critical for the PEMFC.However,current developments still remain extremely challenging with respect to highly active and stable catalysts in practical operation,controlled distribution of ionomer on the catalyst surface for reducing catalyst poisoning and oxygen penetration losses and 3D(three-dimensional)-ordered catalyst layers with low Knudsen diffusion losses of oxygen molecular.This review paper focuses on impacts of the cathode development on automotive fuel cell systems and concludes design directions to provide the greatest benefit.展开更多
基金National Joint Foundation for Natural Science Focus(Project No.:U 19A20107).
文摘Dispersion parameter is an important parameter for the establishment of groundwater solute transport model.The dispersion test uses sodium chloride as a tracer,which was conducted in a site in Jilin City.The standard curve comparison method was used to solve the dispersion parameters of the aquifer under the natural flow field.The test results show that under the natural flow field,the longitudinal dispersion of unconfined aquifer in Jilin City is 0.400m,and the transverse dispersion is 1.933×10-5~6.557×10-3m;while the longitudinal dispersion coefficient is 0.246m2/d,the transverse dispersion coefficient is 1.191×10-5~4.039×10-3m2/d.The above results can provide an important parameter basis for the establishment of groundwater solute transport model,the accurate prediction of temporal and spatial variation of pollutant concentration in groundwater and the formulation of groundwater pollution prevention and control scheme.
基金the Key Research and Development Project of Anhui Province(1804a07020108,201904a06020056,202104a06020012)Independent Project of Anhui Key Laboratory of Smart Agricultural Technology and Equipment(APKLSATE2019X001).
文摘The accurate identification,detection,and segmentation of tea buds and leaves are important factors for realizing intelligent tea picking.A tea picking point location method based on the region-based convolutional neural network(R-CNN)Mask-RCNN is proposed,and a tea bud and leaf and picking point recognition model is established.First,tea buds and leaf pictures are collected in a complex environment,the Resnet50 residual network and a feature pyramid network(FPN)are used to extract bud and leaf features,and preliminary classification and preselection box regression training-performed on the feature maps through a regional proposal network(RPN).Second,the regional feature aggregation method(RoIAlign)is used to eliminate the quantization error,and the feature map of the preselected region of interest(ROI)is converted into a fixed-size feature map.The output module of the model realizes the functions of classification,regression and segmentation.Finally,through the output mask image and the positioning algorithm the positioning of the picking points of tea buds and leaves is determined.One hundred tea tree bud and leaf pictures in a complex environment are selected for testing.The experimental results show that the average detection accuracy rate reaches 93.95%and that the recall rate reaches 92.48%.The tea picking location method presented in this paper is more versatile and robust in complex environments.
基金supported by Key R&D International Cooperation Projects(Grant No:2019YFE0114500)National Natural Science Foun-dation of China(Grant Nos:81904027,81973001)+1 种基金Medical Health Sci-ence and Technology Project of Zhejiang Provincial Health Commis-sion(Grant Nos:2018KY545,2019KY471,2019KY472)Natural Science Foundation of Zhejiang Chinese Medical University(Grant Nos:2014ZR03,KC201901,2019ZR02,2019ZZ04).
文摘Background:Heatwave events occur more frequently,accompanied by a significant increase in the ambient concentration of fine particulate matter(PM 2.5).Epidemiological and experimental studies have suggested that heat stress or PM 2.5 exposure would impair glucose homeostasis and insulin sensitivity.Objective:To explore the joint effects of heat stress and PM 2.5 exposure on glucose metabolism and hepatic insulin pathway.Methods:C57BL/6 mice were randomly divided into filtered air(FA)group,fine particulate matter(PM)group,filtered air combined with heat stress(FH)group,and PM combined with heat stress(PH)group.Mice were exposed to PM for a total of 6 weeks,and heat stress combined with PM exposure was applied at the 5th and 6th weeks via a whole-body exposure system.Systemic glucose homeostasis,insulin sensitivity,and circulating inflammatory cytokines were examined.HSP72 expression and insulin signaling in the liver were measured.Results:Glucose tolerance and insulin sensitivity were impaired in response to heat stress,accompanied by less-ened hepatic GLUT2 expression and inhibited insulin signaling pathway.No synergistic effects of heat stress and PM 2.5 exposure on glucose homeostasis were observed,while heat-upregulated HSP72 expression was attenuated with accumulated TNF𝛼induced by further PM 2.5 exposure.Conclusion:Heat stress combined with PM 2.5 exposure induced TNF𝛼,which could inhibit heat-elevated hepatic HSP72 expression.Elevated circulating TNF𝛼impaired hepatic insulin signaling and GLUT2 expression.Then,glucose homeostasis was perturbed,and insulin action was impaired.
基金Supported by the National Natural Science Foundation of China[the Patterns Differentiation Mode of Main TCM Clinical Symptoms Based on Complex System Method(No.81270050)Information Extraction From TCM Inquiry and the Deducting Method of Patterns Differentiation Based on Feature Selection(No.30901897)+2 种基金Common Syndrome Diagnosis of Traditional Chinese Medicine Based on The Integration of Four Diagnosis Methods(No.81173199)]College Students' Scientific Innovation Foundation of Shanghai University of TCM[SHUTCMCXHDZ(2011)03]the Foundation for Training Talents of National Basic Scientific Research(No.J1103607)
文摘OBJECTIVE: Apply spectral clustering to analyze the patterns of symptoms in patients with chronic gastritis(CG).METHODS: Based on 919 CG subjects, we applied mutual information feature selection to choose the positively correlated symptoms with each pattern.Then, we used the Shi and Malik spectral clustering algorithm to select the top 20 correlated symptoms.RESULTS: We ascertained the results of six patterns.There were three categories for the pattern of accumulation of damp heat in the spleen-stomach(0.00332). There were six categories for the pattern of dampness obstructing the spleen-stomach(0.02466). There were two categories for the pattern of spleen-stomach Qi deficiency(0.013 89).There were three categories for the pattern of spleen-stomach deficiency cold(0.009 15). There were five categories for the pattern of liver-Qistagnation(0.01910).There were four categories for the pattern of stagnant heat in the liver-stomach(0.00585).CONCLUSION: Most of the spectral clustering results of the symptoms of CG patterns were in accordance with clinical experience and Traditional Chinese Medicine theory. Most categories suggested the nature and/or location of the disease.
基金We gratefully acknowledge the financial supports from the National Natural Science Foundation of China(Grant No.21576164)the European Union’s Horizon 2020 research and innovation program H2020-MSCA-IF-2014(Grant No.658217)Anhui new energy vehicle and intelligent network vehicle industry technology innovation project(Grant No.2018-599)of Anhui development and Reform Commission.
文摘The platinum nanowires have been verified to be a promising catalyst to promote the performance of proton exchange membrane fuel cells.In this paper,accurately controlled growth of nanowires in a carbon matrix is achieved for reducing Pt loading.The effects of formic acid concentration and reaction temperature on the morphology and size of the Pt nanowires,as well as their electrochemical performances in a single cell,are investigated.The results showed that the increase in the formic acid concentration results in a volcano trend with the length of Pt nanowires.With increasing reduction temperature,the diameter of Pt nanowires increases while Pt particles evolve from one-dimensional to zero-dimensional up to 40°C.A mechanism of the Pt nanowires growth is proposed.The optimized Pt nanowires electrode exhibits a power density(based on electrochemical active surface area)79%higher than conventional Pt/C one.The control strategy obtained contributes to the design and control of novel nanostructures in nano-synthesis and catalyst applications.
基金SD would like to acknowledge support from the Engineering and Physical Sciences Research Council(EPSRC,EP/L015749/1)SS gratefully acknowledges the financial supports from the National Natural Science Foundation of China under grant agreement No 21576164Thanks are also to the support from Guangdong Academy of Sciences project(2019 GDASYL-0503005).
文摘An advanced cathode design can improve the power performance and durability of proton exchange membrane fuel cells(PEMFCs),thus reducing the stack cost of fuel cell vehicles(FCVs).Recent studies on highly active Pt alloy catalysts,short-side-chain polyfluorinated sulfonic acid(PFSA)ionomer and 3D-ordered electrodes have imparted PEMFCs with boosted power density.To achieve the compacted stack target of 6 kW/L or above for the wide commercialization of FCVs,developing available cathodes for high-power-density operation is critical for the PEMFC.However,current developments still remain extremely challenging with respect to highly active and stable catalysts in practical operation,controlled distribution of ionomer on the catalyst surface for reducing catalyst poisoning and oxygen penetration losses and 3D(three-dimensional)-ordered catalyst layers with low Knudsen diffusion losses of oxygen molecular.This review paper focuses on impacts of the cathode development on automotive fuel cell systems and concludes design directions to provide the greatest benefit.