Sandwich piezoelectric semiconductor(PS)structures have significant applications in multi-functional semiconductor devices.The analysis of multi-field coupling behaviors of PS structures is of fundamental importance i...Sandwich piezoelectric semiconductor(PS)structures have significant applications in multi-functional semiconductor devices.The analysis of multi-field coupling behaviors of PS structures is of fundamental importance in developing novel PS devices.In this paper,we develop a general temperature-deformation-polarization-carrier(TDPC)coupling model for sandwich-type PS beams involving pyroelectricity under thermal loadings,based on three-dimensional(3D)basic equations of the thermo-piezoelectric semiconductor(TPS).We derive analytical solutions for extensional,bending,and buckling deformations of simply-supported sandwich n-type PS beams subjected to open-circuit and electrically isolated boundary conditions.The accuracy of the proposed model in this paper is verified through finite element simulations implemented in the COMSOL software.Numerical results show that the initial electron concentration and the thickness ratio of the PS layer to the beam's total thickness have a significant effect on thermally induced extensional and bending responses,as well as critical buckling mechanical and thermal loadings.This study provides a theoretical framework and guidance for designing semiconductor devices based on sandwich PS beam structures.展开更多
Antibiotics,as widely used antibacterial drug,exist in various environmental media.Antibiotic residues can affect biological metabolism and lead to bacterial resistance and the formation of antibiotic-resistance genes...Antibiotics,as widely used antibacterial drug,exist in various environmental media.Antibiotic residues can affect biological metabolism and lead to bacterial resistance and the formation of antibiotic-resistance genes,posing a threat to human health and ecological safety.Establishing efficient detection methods for antibiotics and antibiotic-resistance genes has great environmental significance.Fluorescence detection methods,due to their fast response,high sensitivity and specificity,and low-cost,are widely used in chemical and biological sensing.This review first summarizes the pre-treatment methods for different types of environmental samples,and then focuses on the recent advances of fluorescence methods for the detection of antibiotics and antibiotic-resistance genes.Finally,main challenges and future research directions of fluorescence methods for antibiotic and antibiotic-resistance genes detection are discussed.This review highlights the promising prospect of fluorescence methods in-situ detection and monitoring of antibiotics and antibiotic-resistance genes,and provides guidance for the construction of overall risk assessment system of environmental media.展开更多
Field-effect transistors(FETs)present highly sensitive,rapid,and in situ detection capability in chemical and biological analysis.Recently,two-dimensional(2D)transition-metal dichalcogenides(TMDCs)attract significant ...Field-effect transistors(FETs)present highly sensitive,rapid,and in situ detection capability in chemical and biological analysis.Recently,two-dimensional(2D)transition-metal dichalcogenides(TMDCs)attract significant attention as FET channel due to their unique structures and outstanding properties.With the booming of studies on TMDC FETs,we aim to give a timely review on TMDCbased FET sensors for environmental analysis in different media.First,theoretical basics on TMDC and FET sensor are introduced.Then,recent advances of TMDC FET sensor for pollutant detection in gaseous and aqueous media are,respectively,discussed.At last,future perspectives and challenges in practical application and commercialization are given for TMDC FET sensors.This article provides an overview on TMDC sensors for a wide variety of analytes with an emphasize on the increasing demand of advanced sensing technologies in environmental analysis.展开更多
As a global pollutant, high levels of mercury（Hg） have been found in remote ecosystem due to the long range atmospheric transport. In this study, a total of 60 fish samples were collected from four rivers across the...As a global pollutant, high levels of mercury（Hg） have been found in remote ecosystem due to the long range atmospheric transport. In this study, a total of 60 fish samples were collected from four rivers across the Tibetan Plateau to study the accumulation of Hg in remote and high-altitude aquatic environment. The total Hg（THg） and methylmercury（MeHg） in fish muscles ranged from 11 to 2097 ng/g dry weight（dw）（average： 819 ng/g dw）and from 14 to 1960 ng/g dw（average： 756 ng/g dw）, respectively. Significantly positive linear relationships were observed between the THg（r = 0.591, p 〈 0.01, n = 36） and MeHg concentrations（r = 0.473, p 〈 0.01, n = 36） with the trophic level of fish from Lhasa River,suggesting trophic transfer and biomagnification of Hg in this aquatic ecosystem. Moreover,the THg levels in fish had significantly positive correlations with the length（r = 0.316,p 〈 0.05, n = 60） and weight（r = 0.271, p 〈 0.05, n = 60） of fish. The high levels of Hg were attributed to the slow growth and long lifespan of the fish under this sterile and cold environment. Risk assessment revealed that the consumption of Oxygymnocypris stewartii,Schizothorax macropogon, Schizothorax waltoni, Schizopygopsis younghusbandi and Schizothorax o＇connori would lead to a high exposure to Me Hg.展开更多
基金Project supported by the National Natural Science Foundation of China(No.11672265)。
文摘Sandwich piezoelectric semiconductor(PS)structures have significant applications in multi-functional semiconductor devices.The analysis of multi-field coupling behaviors of PS structures is of fundamental importance in developing novel PS devices.In this paper,we develop a general temperature-deformation-polarization-carrier(TDPC)coupling model for sandwich-type PS beams involving pyroelectricity under thermal loadings,based on three-dimensional(3D)basic equations of the thermo-piezoelectric semiconductor(TPS).We derive analytical solutions for extensional,bending,and buckling deformations of simply-supported sandwich n-type PS beams subjected to open-circuit and electrically isolated boundary conditions.The accuracy of the proposed model in this paper is verified through finite element simulations implemented in the COMSOL software.Numerical results show that the initial electron concentration and the thickness ratio of the PS layer to the beam's total thickness have a significant effect on thermally induced extensional and bending responses,as well as critical buckling mechanical and thermal loadings.This study provides a theoretical framework and guidance for designing semiconductor devices based on sandwich PS beam structures.
基金supported by the National Key R&D Program of China(No.2019YFC1905400)the National Natural Science Foundation of China(No.22006113)。
文摘Antibiotics,as widely used antibacterial drug,exist in various environmental media.Antibiotic residues can affect biological metabolism and lead to bacterial resistance and the formation of antibiotic-resistance genes,posing a threat to human health and ecological safety.Establishing efficient detection methods for antibiotics and antibiotic-resistance genes has great environmental significance.Fluorescence detection methods,due to their fast response,high sensitivity and specificity,and low-cost,are widely used in chemical and biological sensing.This review first summarizes the pre-treatment methods for different types of environmental samples,and then focuses on the recent advances of fluorescence methods for the detection of antibiotics and antibiotic-resistance genes.Finally,main challenges and future research directions of fluorescence methods for antibiotic and antibiotic-resistance genes detection are discussed.This review highlights the promising prospect of fluorescence methods in-situ detection and monitoring of antibiotics and antibiotic-resistance genes,and provides guidance for the construction of overall risk assessment system of environmental media.
基金the National Natural Science Foundation of China(No.21707102)the Fundamental Research Funds for the Central Universities,China(No.22120180524).
文摘Field-effect transistors(FETs)present highly sensitive,rapid,and in situ detection capability in chemical and biological analysis.Recently,two-dimensional(2D)transition-metal dichalcogenides(TMDCs)attract significant attention as FET channel due to their unique structures and outstanding properties.With the booming of studies on TMDC FETs,we aim to give a timely review on TMDCbased FET sensors for environmental analysis in different media.First,theoretical basics on TMDC and FET sensor are introduced.Then,recent advances of TMDC FET sensor for pollutant detection in gaseous and aqueous media are,respectively,discussed.At last,future perspectives and challenges in practical application and commercialization are given for TMDC FET sensors.This article provides an overview on TMDC sensors for a wide variety of analytes with an emphasize on the increasing demand of advanced sensing technologies in environmental analysis.
基金supported by the National Basic Research Program (973) of China (Nos. 2013CB430004, 2014CB460612)the National Natural Science Foundation of China (Nos. 41422306, 21120102040)the Young Scientists Fund of Research Center for Eco-Environmental Sciences (No. RCEES-QN-20130007F)
文摘As a global pollutant, high levels of mercury（Hg） have been found in remote ecosystem due to the long range atmospheric transport. In this study, a total of 60 fish samples were collected from four rivers across the Tibetan Plateau to study the accumulation of Hg in remote and high-altitude aquatic environment. The total Hg（THg） and methylmercury（MeHg） in fish muscles ranged from 11 to 2097 ng/g dry weight（dw）（average： 819 ng/g dw）and from 14 to 1960 ng/g dw（average： 756 ng/g dw）, respectively. Significantly positive linear relationships were observed between the THg（r = 0.591, p 〈 0.01, n = 36） and MeHg concentrations（r = 0.473, p 〈 0.01, n = 36） with the trophic level of fish from Lhasa River,suggesting trophic transfer and biomagnification of Hg in this aquatic ecosystem. Moreover,the THg levels in fish had significantly positive correlations with the length（r = 0.316,p 〈 0.05, n = 60） and weight（r = 0.271, p 〈 0.05, n = 60） of fish. The high levels of Hg were attributed to the slow growth and long lifespan of the fish under this sterile and cold environment. Risk assessment revealed that the consumption of Oxygymnocypris stewartii,Schizothorax macropogon, Schizothorax waltoni, Schizopygopsis younghusbandi and Schizothorax o＇connori would lead to a high exposure to Me Hg.
