The anti-inflammatory properties of silkworm pupa peptide(SPP)have been recognized for their potential benefits in colitis treatment.However,the underlying mechanism of SPP in colitis animal models remains unclear.The...The anti-inflammatory properties of silkworm pupa peptide(SPP)have been recognized for their potential benefits in colitis treatment.However,the underlying mechanism of SPP in colitis animal models remains unclear.The objective of our work was to investigate the improving effect and the mechanism of action of SPP on a mouse model of dextran sulfate sodium(DSS)-induced colitis.The findings suggested that SPP effectively eased ulcerative colitis(UC)symptoms in mice by decreasing disease activity index,ameliorating histopathological injury,and decreasing serum and colonic markers of inflammation.In addition,our research findings demonstrated that SPP restored intestinal barrier function by increasing the production of tight junction proteins such as zonula occludens-1(ZO-1),claudin-1,claudin-3,occludin,and adherens junction protein E-cadherin1.Further,SPP supplementation enhanced the concentration of short-chain fatty acids and positively altered the makeup of the gut bacteria in the mice's gut.These findings underscore SPP's ability to slow the progression of colitis and point to its possible use as a functional component in dietary supplements for the prevention of early-stage colitis.展开更多
Photocatalytic CO_(2)reduction to produce high value-added carbon-based fuel has been proposed as a promising approach to mitigate global warming issues.However,the conversion efficiency and product selectivity are st...Photocatalytic CO_(2)reduction to produce high value-added carbon-based fuel has been proposed as a promising approach to mitigate global warming issues.However,the conversion efficiency and product selectivity are still low due to the sluggish dynamics of transfer processes involved in proton-assisted multi-electron reactions.Lowering the formation energy barriers of intermediate products is an effective method to enhance the selectivity and productivity of final products.In this study,we aim to regulate the surface electronic structure of Bi_(2)WO_(6)by doping surface chlorine atoms to achieve effective photocatalytic CO_(2)reduction.Surface Cl atoms can enhance the absorption ability of light,affect its energy band structure and promote charge separation.Combined with DFT calculations,it is revealed that surface Cl atoms can not only change the surface charge distribution which affects the competitive adsorption of H_(2)O and CO_(2),but also lower the formation energy barrier of intermediate products to generate more intermediate*COOH,thus facilitating CO production.Overall,this study demonstrates a promising surface halogenation strategy to enhance the photocatalytic CO_(2)reduction activity of a layered structure Bi-based catalyst.展开更多
Investigations into the aerodynamic properties of vertical sound barriers exposed to high-speed operations employ computational fluid dynamics.The primary focus of this research is to evaluate the influence of train s...Investigations into the aerodynamic properties of vertical sound barriers exposed to high-speed operations employ computational fluid dynamics.The primary focus of this research is to evaluate the influence of train speed and the distance(D)from the track centerline under various operating conditions.The findings elucidate a marked elevation in the aerodynamic effect amplitude on sound barriers as train speeds increase.In single-train passages,the aerodynamic effect amplitude manifests a direct relationship with the square of the train speed.When two trains pass each other,the aerodynamic amplitude intensifies due to an additional aerodynamic increment on the sound barrier.This increment exhibits an approximate quadratic correlation with the retrograde train speed.Notably,the impact of high-speed trains on sound barrier aerodynamics surpasses that of low-speed trains,and this discrepancy amplifies with larger speed differentials between trains.Moreover,the train-induced aerodynamic effect diminishes significantly with greater distance(D),with occurrences of pressure coefficient(CP)exceeding the standard thresholds during dual-train passages.This study culminates in the formulation of universal equations for quantifying the influence of train speed and distance(D)on sound barrier aerodynamic characteristics across various operational scenarios.展开更多
We study the phase,Larmor and dwell times of a particle scattered off triangular barriers(TBs).It is interesting that the dependences of dwell,reflective phase and Larmor times on the wave number,barrier width and hei...We study the phase,Larmor and dwell times of a particle scattered off triangular barriers(TBs).It is interesting that the dependences of dwell,reflective phase and Larmor times on the wave number,barrier width and height for a pair of mirror-symmetric(MS)exact triangular barriers(ETBs)are quite different,as the two ETBs have quite distinct scattering surfaces.In comparison,the dependence of the transmitted phase or Larmor times is exactly the same,since the transmitted amplitudes are the same for a pair of MS TBs.We further study the Hartman effect by defining the phase and Larmor velocities associated with the phase and Larmor times.We find no barrier width saturation effect for the transmitted and reflected times.This is indicated by the fact that all the velocities approach finite constants that are much smaller than the speed of light in vacuum for TBs with positive-slope impact faces.As for ETBs with vertical left edges,the naive velocities seem to also indicate the absence of the Hartman effect.These are quite distinct from rectangular barriers and may shed new light on the clarification of the tunneling time issues.展开更多
BACKGROUND: A poor communication with immigrants can lead to inappropriate use of healthcare services, greater risk of misdiagnosis, and lower compliance with treatment. As precise information about communication betw...BACKGROUND: A poor communication with immigrants can lead to inappropriate use of healthcare services, greater risk of misdiagnosis, and lower compliance with treatment. As precise information about communication between emergency physicians(EPs) and immigrants is lacking, we analyzed difficulties in communicating with immigrants in the emergency department(ED) and their possible associations with demographic data, geographical origin and clinical characteristics.METHODS: In an ED with approximately 85 000 visits per year, a multiple-choice questionnaire was given to the EPs 4 months after discharge of each immigrant in 2011.RESULTS: Linguistic comprehension was optimal or partial in the majority of patients. Signifi cant barriers were noted in nearly one fourth of patients, for only half of them compatriots who were able to translate. Linguistic barriers were mainly found in older and sicker patients; they were also frequently seen in patients coming from western Africa and southern Europe. Non-linguistic barriers were perceived by EPs in a minority of patients, more frequently in the elderly and frequent attenders. Factors independently associated with a poor f inal comprehension led to linguistic barriers, non-linguistic obstacles, the absence of intermediaries, and the presence of patient's fear and hostility. The latter probably is a consequence, not the cause, of a poor comprehension.CONCLUSION: Linguistic and non-linguistic barriers, although quite infrequent, are the main factors that compromise communication with immigrants in the ED, with negative effects especially on elderly and more seriously ill patients as well as on physician satisfaction and appropriateness in using services.展开更多
Nowadays,the development of economy as well as the progress of society requires better English competence of college students.As a result,a large number of college students are obsessedby affective barriers in their E...Nowadays,the development of economy as well as the progress of society requires better English competence of college students.As a result,a large number of college students are obsessedby affective barriers in their English learning,especially when they have to cope with CET 4 or CET 6,which is more and more difficult.This paper focuses on how to help college students overcome their affective barriers more effectively to improve their English learning.展开更多
Trapping of oblique surface gravity waves by dual porous barriers near a wall is studied in the presence of step type varying bottom bed that is connected on both sides by water of uniform depths. The porous barriers ...Trapping of oblique surface gravity waves by dual porous barriers near a wall is studied in the presence of step type varying bottom bed that is connected on both sides by water of uniform depths. The porous barriers are assumed to be fixed at a certain distance in front of a vertical rigid wall. Using linear water wave theory and Darcy's law for flow past porous structure, the physical problem is converted into a boundary value problem. Using eigenfunction expansion in the uniform bottom bed region and modified mild-slope equation in the varying bottom bed region, the mathematical problem is handled for solution. Moreover, certain jump conditions are used to account for mass conservation at slope discontinuities in the bottom bed profile. To understand the effect of dual porous barriers in creating tranquility zone and minimum load on the sea wall, reflection coefficient, wave forces acting on the barrier and the wall, and surface wave elevation are computed and analyzed for different values of depth ratio, porous-effect parameter, incident wave angle, gap between the barriers and wall and slope length of undulated bottom. The study reveals that with moderate porosity and suitable gap between barriers and sea wall, using dual barriers an effective wave trapping system can be developed which will exert less wave force on the barriers and the rigid wall. The proposed wave trapping system is likely to be of immense help for protecting various facilities/infrastructures in coastal environment.展开更多
The spin-dependent conductance and magnetoresistance ratio （MRR） for a semiconductor heterostructures consisting of two magnetic barriers with different height and space have been investigated by the transfer-matrix...The spin-dependent conductance and magnetoresistance ratio （MRR） for a semiconductor heterostructures consisting of two magnetic barriers with different height and space have been investigated by the transfer-matrix method. It is shown that the splitting of the conductance for parallel and antiparallel magnetization configurations results in tremendous spin-dependent MRR, and the maximal MRRs reach 5300% and 3800% for the magnetic barrier spaces W = 81.3 and 243.9 nm, respectively. The obtained spin-filtering transport property of nanostructures with magnetic barriers may be useful to magnetic-barrier-based spintronics.展开更多
The physical vapor deposition method is an effective way to deposit Al2O3 and Er2O3 on 316 L stainless steel substrates acting as tritium permeation barriers in a fusion reactor. The distribution of residual thermal s...The physical vapor deposition method is an effective way to deposit Al2O3 and Er2O3 on 316 L stainless steel substrates acting as tritium permeation barriers in a fusion reactor. The distribution of residual thermal stress is calculated both in Al2O3 and Er2O3 coating systems with planar and rough substrates using finite element analysis. The parameters influencing the thermal stress in the sputter process are analyzed, such as coating and substrate properties, temperature and Young＇s modulus. This work shows that the thermal stress in Al2O3 and Er2O3 coating systems exhibit a linear relationship with substrate thickness, temperature and Young＇s modulus.However, this relationship is inversed with coating thickness. In addition, the rough substrate surface can increase the thermal stress in the process of coating deposition. The adhesive strength between the coating and the substrate is evaluated by the shear stress. Due to the higher compressive shear stress, the Al2O3 coating has a better adhesive strength with a 316 L stainless steel substrate than the Er2O3 coating. Furthermore, the analysis shows that it is a useful way to improve adhesive strength with increasing interface roughness.展开更多
This paper probes into formation and problems of cultural barriers in actual communication.It analyzes reasons why that these cultural barriers come into being and proposes solutions to these problems with several exa...This paper probes into formation and problems of cultural barriers in actual communication.It analyzes reasons why that these cultural barriers come into being and proposes solutions to these problems with several examples.展开更多
Aesthetic communication plays significant role in poetry translation,for it affects the target text in both internal structure and external structure. This paper analyzes the comparison of nine versions of English tra...Aesthetic communication plays significant role in poetry translation,for it affects the target text in both internal structure and external structure. This paper analyzes the comparison of nine versions of English translation of classic Chinese poem —Jing Ye Si written by Li Bai(李白) from the perspective of aesthetic communication barriers and reiterates the factors which influence the translation target texts.展开更多
The advantages of nitride-based dual-wavelength light-emitting diodes （LEDs） with an InA1N electron blocking layer （EBL） are studied. The emission spectra, carrier concentration in the quantum wells （QWs）, energ...The advantages of nitride-based dual-wavelength light-emitting diodes （LEDs） with an InA1N electron blocking layer （EBL） are studied. The emission spectra, carrier concentration in the quantum wells （QWs）, energy band and internal quantum efficiency （IQE） are investigated. The simulation results indicate that an LED with an InA1N EBL performs better over a conventional LED with an A1GaN EBL and an LED with p-type-doped QW barriers. All of the advantages are due to the enhancement of carrier confinement and the lower electron leakage current. The simulation results also show that the efficiency droop is markedly improved and the luminous intensity is greatly enhanced when an InAlN EBL is used.展开更多
The diffraction of obliquely incident wave by two unequal barriers with different porosity in infinitely deep water is investigated by using two-dimensional linearized potential theory.Reflection and transmission coef...The diffraction of obliquely incident wave by two unequal barriers with different porosity in infinitely deep water is investigated by using two-dimensional linearized potential theory.Reflection and transmission coefficients are computed numerically using appropriate Galerkin approximations for two partially immersed and two submerged barriers.The amount of energy dissipation due to the permeable barriers is derived using Green’s integral theorem.The coefficient of wave force is determined using the linear Bernoulli equation of dynamic pressure jump on the porous barriers.The numerical results of hydrodynamics quantities are illustrated graphically.展开更多
GaN/InGaN superlattice barriers are used in InGaN-based light-emitting diodes （LEDs）. The electrostatic field in the quantum wells, electron hole wavefunction overlap, carrier concentration, spontaneous emission spe...GaN/InGaN superlattice barriers are used in InGaN-based light-emitting diodes （LEDs）. The electrostatic field in the quantum wells, electron hole wavefunction overlap, carrier concentration, spontaneous emission spectrum, light-current performance curve, and internal quantum efficiency are numerically investigated using the APSYS simulation software. It is found that the structure with GaN/InGaN superlattice barriers shows improved light output power, and lower current leakage and efficiency droop. According to our numerical simulation and analysis, these improvements in the electrical and optical characteristics are mainly attributed to the alleviation of the electrostatic field in the active region.展开更多
The adding of ZnMgO asymmetric double barriers(ADB)in p-ZnO2(Li,N)/n-ZnO homojunction affects the p-n junction device performance prominently.Two different homojunctions are fabricated on Si(100)substrates by pulsed l...The adding of ZnMgO asymmetric double barriers(ADB)in p-ZnO2(Li,N)/n-ZnO homojunction affects the p-n junction device performance prominently.Two different homojunctions are fabricated on Si(100)substrates by pulsed laser deposition;one is the traditional p-ZnO2(Li,N)/n-ZnO homojunction with different thicknesses named as S_(1)(250 nm)and S2(500 nm),the other is the one with ADB embedded in the n-layer named as Q(265 nm).From the photoluminescence spectra,defect luminescence present in the S-series devices is effectively limited in the Q device.The current-voltage curve of the Q device shows Zener-diode rectification property because the two-dimensional electron gas tunnels through the narrow ZnMgO barrier under a reverse bias,thus decreasing the working p-n homojunction thickness from 500 nm to 265 nm.The ADB-modified homojunction shows higher carrier mobility in the Q device.The electroluminescence of the ZnO homojunction is improved in Q compared to S_(2),because the holes in p-type ZnO(Li,N)can cross the wide ZnMgO barrier under a forward bias voltage into the ZnO quantum well.Therefore,electron-hole recombination occurs in the narrow bandgap of n-type ZnO,creating an ultraviolet light-emitting diode using the ZnO homojunction.展开更多
The advantages of InGaN based light-emitting diodes with InGaN/GaN multilayer barriers are studied. It is found that the structure with InGaN/GaN multilayer barriers shows improved light output power, lower current le...The advantages of InGaN based light-emitting diodes with InGaN/GaN multilayer barriers are studied. It is found that the structure with InGaN/GaN multilayer barriers shows improved light output power, lower current leakage, and less efficiency droop over its conventional InGaN/GaN counterparts. Based on the numerical simulation and analysis, these improvements on the electrical and the optical characteristics are mainly attributed to the alleviation of the electrostatic field in the quantum wells （QWs） when the InGaN/GaN multilayer barriers are used.展开更多
The paper discusses the characteristics of next generation services, and analyzes its development barriers and cut-in points.Broadband services that NGN offers have to transit from an unknown state to an popular state...The paper discusses the characteristics of next generation services, and analyzes its development barriers and cut-in points.Broadband services that NGN offers have to transit from an unknown state to an popular state to become a scale economy.Personal information and communication services and multimedia entertainment services will be the cut-in points.展开更多
Traffic barriers are in widespread all around the USA as safety countermeasures for reducing the severity of run-off-road crashes. The effect of traffic barriers’ dimension had been ignored in past real-world crash s...Traffic barriers are in widespread all around the USA as safety countermeasures for reducing the severity of run-off-road crashes. The effect of traffic barriers’ dimension had been ignored in past real-world crash studies due to the considerable cost and time needed for collecting field data. This paper presented two new analytical models to investigate the effect of different variables on the severity of crashes involving traffic barriers, and end treatments. For this reason, a field survey was conducted on over 1.3 million linear feet of traffic barriers (approximately 4,176 miles road) in Wyoming to measure traffic barriers’ geometric features like height, length, offset, and slope rate. The collected data included 55% of all non-interstate roads of Wyoming. Based on results, the crashes involving box beam barriers were less severe than the crashes involved with W-beam or concrete barriers. The traffic barriers with a height between 28 and 31 in. were found safer than the traffic barriers shorter than 28 in., while there was no significant difference between the traffic barriers taller than 31 in. to those shorter than 28 in. in terms of crash severity. The end treatments located nearer to the traffic lane had lower crash severity.展开更多
This paper defines translation as an act of communication in a cross-cultural context,and then discusses the unavoidable cultural barriers in the process of translation.While cultures are composed of a large number of...This paper defines translation as an act of communication in a cross-cultural context,and then discusses the unavoidable cultural barriers in the process of translation.While cultures are composed of a large number of elements,this paper is just mainlyrelated to three elements including historical culture difference,geographical difference,and social culture difference.Through analyzing the cultural barriers from different respective,the author is aimed to remind the readers that when do translation,they must have some culture consciousness and relative cultural translation strategies in mind.In the last part of the paper strategies of translation(especially for the translation between English and Chinese)are put forward,by means of which individuals could tackle the cultural barriers in the process of translation,making for a good communication between different cultures.展开更多
Emotion is an indispensable factor in English writing.However,product-oriented teaching has paid too much attention to the interior form of writing with ignoring the emotional factors.Based on the analysis of emotiona...Emotion is an indispensable factor in English writing.However,product-oriented teaching has paid too much attention to the interior form of writing with ignoring the emotional factors.Based on the analysis of emotional barriers and corresponding drawbacks caused by the traditional teaching method,this study proposes both communicative approach and process-oriented approach to help college students develop positive emotions in English writing.展开更多
基金supported by the National Key Research and Development Program of China(2023YFF1103802)。
文摘The anti-inflammatory properties of silkworm pupa peptide(SPP)have been recognized for their potential benefits in colitis treatment.However,the underlying mechanism of SPP in colitis animal models remains unclear.The objective of our work was to investigate the improving effect and the mechanism of action of SPP on a mouse model of dextran sulfate sodium(DSS)-induced colitis.The findings suggested that SPP effectively eased ulcerative colitis(UC)symptoms in mice by decreasing disease activity index,ameliorating histopathological injury,and decreasing serum and colonic markers of inflammation.In addition,our research findings demonstrated that SPP restored intestinal barrier function by increasing the production of tight junction proteins such as zonula occludens-1(ZO-1),claudin-1,claudin-3,occludin,and adherens junction protein E-cadherin1.Further,SPP supplementation enhanced the concentration of short-chain fatty acids and positively altered the makeup of the gut bacteria in the mice's gut.These findings underscore SPP's ability to slow the progression of colitis and point to its possible use as a functional component in dietary supplements for the prevention of early-stage colitis.
基金supported by the National Natural Science Foundation of China(Grant No.51708078)Natural Science Foundation of Chongqing(Grant No.CSTB2022NSCQ-MSX0815)+2 种基金Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJQN202200542)the Chongqing Innovative Research Group Project(Grant No.CXQT21015)Foundation of Chongqing Normal University(22XLB022).
文摘Photocatalytic CO_(2)reduction to produce high value-added carbon-based fuel has been proposed as a promising approach to mitigate global warming issues.However,the conversion efficiency and product selectivity are still low due to the sluggish dynamics of transfer processes involved in proton-assisted multi-electron reactions.Lowering the formation energy barriers of intermediate products is an effective method to enhance the selectivity and productivity of final products.In this study,we aim to regulate the surface electronic structure of Bi_(2)WO_(6)by doping surface chlorine atoms to achieve effective photocatalytic CO_(2)reduction.Surface Cl atoms can enhance the absorption ability of light,affect its energy band structure and promote charge separation.Combined with DFT calculations,it is revealed that surface Cl atoms can not only change the surface charge distribution which affects the competitive adsorption of H_(2)O and CO_(2),but also lower the formation energy barrier of intermediate products to generate more intermediate*COOH,thus facilitating CO production.Overall,this study demonstrates a promising surface halogenation strategy to enhance the photocatalytic CO_(2)reduction activity of a layered structure Bi-based catalyst.
基金This study was supported in part by the National Natural Science Foundation of China under Grant Nos.52278463,52208505,and 52202422.
文摘Investigations into the aerodynamic properties of vertical sound barriers exposed to high-speed operations employ computational fluid dynamics.The primary focus of this research is to evaluate the influence of train speed and the distance(D)from the track centerline under various operating conditions.The findings elucidate a marked elevation in the aerodynamic effect amplitude on sound barriers as train speeds increase.In single-train passages,the aerodynamic effect amplitude manifests a direct relationship with the square of the train speed.When two trains pass each other,the aerodynamic amplitude intensifies due to an additional aerodynamic increment on the sound barrier.This increment exhibits an approximate quadratic correlation with the retrograde train speed.Notably,the impact of high-speed trains on sound barrier aerodynamics surpasses that of low-speed trains,and this discrepancy amplifies with larger speed differentials between trains.Moreover,the train-induced aerodynamic effect diminishes significantly with greater distance(D),with occurrences of pressure coefficient(CP)exceeding the standard thresholds during dual-train passages.This study culminates in the formulation of universal equations for quantifying the influence of train speed and distance(D)on sound barrier aerodynamic characteristics across various operational scenarios.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11974108,11875127,and 12211530044)the Fundamental Research Funds for the Central Universities(Grant No.2020MS052).
文摘We study the phase,Larmor and dwell times of a particle scattered off triangular barriers(TBs).It is interesting that the dependences of dwell,reflective phase and Larmor times on the wave number,barrier width and height for a pair of mirror-symmetric(MS)exact triangular barriers(ETBs)are quite different,as the two ETBs have quite distinct scattering surfaces.In comparison,the dependence of the transmitted phase or Larmor times is exactly the same,since the transmitted amplitudes are the same for a pair of MS TBs.We further study the Hartman effect by defining the phase and Larmor velocities associated with the phase and Larmor times.We find no barrier width saturation effect for the transmitted and reflected times.This is indicated by the fact that all the velocities approach finite constants that are much smaller than the speed of light in vacuum for TBs with positive-slope impact faces.As for ETBs with vertical left edges,the naive velocities seem to also indicate the absence of the Hartman effect.These are quite distinct from rectangular barriers and may shed new light on the clarification of the tunneling time issues.
文摘BACKGROUND: A poor communication with immigrants can lead to inappropriate use of healthcare services, greater risk of misdiagnosis, and lower compliance with treatment. As precise information about communication between emergency physicians(EPs) and immigrants is lacking, we analyzed difficulties in communicating with immigrants in the emergency department(ED) and their possible associations with demographic data, geographical origin and clinical characteristics.METHODS: In an ED with approximately 85 000 visits per year, a multiple-choice questionnaire was given to the EPs 4 months after discharge of each immigrant in 2011.RESULTS: Linguistic comprehension was optimal or partial in the majority of patients. Signifi cant barriers were noted in nearly one fourth of patients, for only half of them compatriots who were able to translate. Linguistic barriers were mainly found in older and sicker patients; they were also frequently seen in patients coming from western Africa and southern Europe. Non-linguistic barriers were perceived by EPs in a minority of patients, more frequently in the elderly and frequent attenders. Factors independently associated with a poor f inal comprehension led to linguistic barriers, non-linguistic obstacles, the absence of intermediaries, and the presence of patient's fear and hostility. The latter probably is a consequence, not the cause, of a poor comprehension.CONCLUSION: Linguistic and non-linguistic barriers, although quite infrequent, are the main factors that compromise communication with immigrants in the ED, with negative effects especially on elderly and more seriously ill patients as well as on physician satisfaction and appropriateness in using services.
文摘Nowadays,the development of economy as well as the progress of society requires better English competence of college students.As a result,a large number of college students are obsessedby affective barriers in their English learning,especially when they have to cope with CET 4 or CET 6,which is more and more difficult.This paper focuses on how to help college students overcome their affective barriers more effectively to improve their English learning.
文摘Trapping of oblique surface gravity waves by dual porous barriers near a wall is studied in the presence of step type varying bottom bed that is connected on both sides by water of uniform depths. The porous barriers are assumed to be fixed at a certain distance in front of a vertical rigid wall. Using linear water wave theory and Darcy's law for flow past porous structure, the physical problem is converted into a boundary value problem. Using eigenfunction expansion in the uniform bottom bed region and modified mild-slope equation in the varying bottom bed region, the mathematical problem is handled for solution. Moreover, certain jump conditions are used to account for mass conservation at slope discontinuities in the bottom bed profile. To understand the effect of dual porous barriers in creating tranquility zone and minimum load on the sea wall, reflection coefficient, wave forces acting on the barrier and the wall, and surface wave elevation are computed and analyzed for different values of depth ratio, porous-effect parameter, incident wave angle, gap between the barriers and wall and slope length of undulated bottom. The study reveals that with moderate porosity and suitable gap between barriers and sea wall, using dual barriers an effective wave trapping system can be developed which will exert less wave force on the barriers and the rigid wall. The proposed wave trapping system is likely to be of immense help for protecting various facilities/infrastructures in coastal environment.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10574042 and 10974052)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20060542002)
文摘The spin-dependent conductance and magnetoresistance ratio （MRR） for a semiconductor heterostructures consisting of two magnetic barriers with different height and space have been investigated by the transfer-matrix method. It is shown that the splitting of the conductance for parallel and antiparallel magnetization configurations results in tremendous spin-dependent MRR, and the maximal MRRs reach 5300% and 3800% for the magnetic barrier spaces W = 81.3 and 243.9 nm, respectively. The obtained spin-filtering transport property of nanostructures with magnetic barriers may be useful to magnetic-barrier-based spintronics.
基金supported by National Natural Science Foundation of China(Nos.11505121 and 51171124)
文摘The physical vapor deposition method is an effective way to deposit Al2O3 and Er2O3 on 316 L stainless steel substrates acting as tritium permeation barriers in a fusion reactor. The distribution of residual thermal stress is calculated both in Al2O3 and Er2O3 coating systems with planar and rough substrates using finite element analysis. The parameters influencing the thermal stress in the sputter process are analyzed, such as coating and substrate properties, temperature and Young＇s modulus. This work shows that the thermal stress in Al2O3 and Er2O3 coating systems exhibit a linear relationship with substrate thickness, temperature and Young＇s modulus.However, this relationship is inversed with coating thickness. In addition, the rough substrate surface can increase the thermal stress in the process of coating deposition. The adhesive strength between the coating and the substrate is evaluated by the shear stress. Due to the higher compressive shear stress, the Al2O3 coating has a better adhesive strength with a 316 L stainless steel substrate than the Er2O3 coating. Furthermore, the analysis shows that it is a useful way to improve adhesive strength with increasing interface roughness.
文摘This paper probes into formation and problems of cultural barriers in actual communication.It analyzes reasons why that these cultural barriers come into being and proposes solutions to these problems with several examples.
文摘Aesthetic communication plays significant role in poetry translation,for it affects the target text in both internal structure and external structure. This paper analyzes the comparison of nine versions of English translation of classic Chinese poem —Jing Ye Si written by Li Bai(李白) from the perspective of aesthetic communication barriers and reiterates the factors which influence the translation target texts.
基金supported by the Project of Combination of Production and Research Guided by Ministry in 2009,China (Grant No. 2009B090300338)the Doctorate Foundation of the State Education Ministry of China (Grant No. 350163)the Crucial Field and Key Breakthrough Project of Guangdong Province and Hongkong,China (Grant No. 2007A010501008)
文摘The advantages of nitride-based dual-wavelength light-emitting diodes （LEDs） with an InA1N electron blocking layer （EBL） are studied. The emission spectra, carrier concentration in the quantum wells （QWs）, energy band and internal quantum efficiency （IQE） are investigated. The simulation results indicate that an LED with an InA1N EBL performs better over a conventional LED with an A1GaN EBL and an LED with p-type-doped QW barriers. All of the advantages are due to the enhancement of carrier confinement and the lower electron leakage current. The simulation results also show that the efficiency droop is markedly improved and the luminous intensity is greatly enhanced when an InAlN EBL is used.
基金partially supported by a SERB,DST(EMR/2016/005315)
文摘The diffraction of obliquely incident wave by two unequal barriers with different porosity in infinitely deep water is investigated by using two-dimensional linearized potential theory.Reflection and transmission coefficients are computed numerically using appropriate Galerkin approximations for two partially immersed and two submerged barriers.The amount of energy dissipation due to the permeable barriers is derived using Green’s integral theorem.The coefficient of wave force is determined using the linear Bernoulli equation of dynamic pressure jump on the porous barriers.The numerical results of hydrodynamics quantities are illustrated graphically.
基金supported by the National Natural Science Foundation of China (Grant No. 51172079)the Science and Technology Program of Guangdong Province,China (Grant Nos. 2010B090400456 and 2010A081002002)the Science and Technology Program of Guangzhou City, China (Grant No. 2011J4300018)
文摘GaN/InGaN superlattice barriers are used in InGaN-based light-emitting diodes （LEDs）. The electrostatic field in the quantum wells, electron hole wavefunction overlap, carrier concentration, spontaneous emission spectrum, light-current performance curve, and internal quantum efficiency are numerically investigated using the APSYS simulation software. It is found that the structure with GaN/InGaN superlattice barriers shows improved light output power, and lower current leakage and efficiency droop. According to our numerical simulation and analysis, these improvements in the electrical and optical characteristics are mainly attributed to the alleviation of the electrostatic field in the active region.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61540071 and 11705016)Project of Natural Science Research of Higher Education in Jiangsu Province,China(Grant Nos.17KJB510001 and 17KJB140002)+1 种基金Changzhou Sci&Tech Program,China(Grant No.CJ20160026)Changzhou Institute of Technology Science Foundation,China(Grant No.YN1408)
文摘The adding of ZnMgO asymmetric double barriers(ADB)in p-ZnO2(Li,N)/n-ZnO homojunction affects the p-n junction device performance prominently.Two different homojunctions are fabricated on Si(100)substrates by pulsed laser deposition;one is the traditional p-ZnO2(Li,N)/n-ZnO homojunction with different thicknesses named as S_(1)(250 nm)and S2(500 nm),the other is the one with ADB embedded in the n-layer named as Q(265 nm).From the photoluminescence spectra,defect luminescence present in the S-series devices is effectively limited in the Q device.The current-voltage curve of the Q device shows Zener-diode rectification property because the two-dimensional electron gas tunnels through the narrow ZnMgO barrier under a reverse bias,thus decreasing the working p-n homojunction thickness from 500 nm to 265 nm.The ADB-modified homojunction shows higher carrier mobility in the Q device.The electroluminescence of the ZnO homojunction is improved in Q compared to S_(2),because the holes in p-type ZnO(Li,N)can cross the wide ZnMgO barrier under a forward bias voltage into the ZnO quantum well.Therefore,electron-hole recombination occurs in the narrow bandgap of n-type ZnO,creating an ultraviolet light-emitting diode using the ZnO homojunction.
基金Project supported by the National Natural Science Foundation of China (Grant No. 51172079)the Science and Technology Program of Guangdong Province,China (Grant Nos. 2010B090400456 and 2010A081002002)the Science and Technology Program of Guangzhou,China (Grant No. 2011J4300018)
文摘The advantages of InGaN based light-emitting diodes with InGaN/GaN multilayer barriers are studied. It is found that the structure with InGaN/GaN multilayer barriers shows improved light output power, lower current leakage, and less efficiency droop over its conventional InGaN/GaN counterparts. Based on the numerical simulation and analysis, these improvements on the electrical and the optical characteristics are mainly attributed to the alleviation of the electrostatic field in the quantum wells （QWs） when the InGaN/GaN multilayer barriers are used.
文摘The paper discusses the characteristics of next generation services, and analyzes its development barriers and cut-in points.Broadband services that NGN offers have to transit from an unknown state to an popular state to become a scale economy.Personal information and communication services and multimedia entertainment services will be the cut-in points.
基金part of project#RS03218 funded by the Wyoming Department of Transportation(WYDOT)
文摘Traffic barriers are in widespread all around the USA as safety countermeasures for reducing the severity of run-off-road crashes. The effect of traffic barriers’ dimension had been ignored in past real-world crash studies due to the considerable cost and time needed for collecting field data. This paper presented two new analytical models to investigate the effect of different variables on the severity of crashes involving traffic barriers, and end treatments. For this reason, a field survey was conducted on over 1.3 million linear feet of traffic barriers (approximately 4,176 miles road) in Wyoming to measure traffic barriers’ geometric features like height, length, offset, and slope rate. The collected data included 55% of all non-interstate roads of Wyoming. Based on results, the crashes involving box beam barriers were less severe than the crashes involved with W-beam or concrete barriers. The traffic barriers with a height between 28 and 31 in. were found safer than the traffic barriers shorter than 28 in., while there was no significant difference between the traffic barriers taller than 31 in. to those shorter than 28 in. in terms of crash severity. The end treatments located nearer to the traffic lane had lower crash severity.
文摘This paper defines translation as an act of communication in a cross-cultural context,and then discusses the unavoidable cultural barriers in the process of translation.While cultures are composed of a large number of elements,this paper is just mainlyrelated to three elements including historical culture difference,geographical difference,and social culture difference.Through analyzing the cultural barriers from different respective,the author is aimed to remind the readers that when do translation,they must have some culture consciousness and relative cultural translation strategies in mind.In the last part of the paper strategies of translation(especially for the translation between English and Chinese)are put forward,by means of which individuals could tackle the cultural barriers in the process of translation,making for a good communication between different cultures.
文摘Emotion is an indispensable factor in English writing.However,product-oriented teaching has paid too much attention to the interior form of writing with ignoring the emotional factors.Based on the analysis of emotional barriers and corresponding drawbacks caused by the traditional teaching method,this study proposes both communicative approach and process-oriented approach to help college students develop positive emotions in English writing.
