The correlation coefficients of random variables of mechanical structures are generally chosen with experience or even ignored,which cannot actually reflect the effects of parameter uncertainties on reliability.To dis...The correlation coefficients of random variables of mechanical structures are generally chosen with experience or even ignored,which cannot actually reflect the effects of parameter uncertainties on reliability.To discuss the selection problem of the correlation coefficients from the reliability-based sensitivity point of view,the theory principle of the problem is established based on the results of the reliability sensitivity,and the criterion of correlation among random variables is shown.The values of the correlation coefficients are obtained according to the proposed principle and the reliability sensitivity problem is discussed.Numerical studies have shown the following results：（1） If the sensitivity value of correlation coefficient ρ is less than（at what magnitude 0.000 01）,then the correlation could be ignored,which could simplify the procedure without introducing additional error.（2） However,as the difference between ρs,that is the most sensitive to the reliability,and ρR,that is with the smallest reliability,is less than 0.001,ρs is suggested to model the dependency of random variables.This could ensure the robust quality of system without the loss of safety requirement.（3） In the case of ｜Eabs｜ρ0.001 and also ｜Erel｜ρ0.001,ρR should be employed to quantify the correlation among random variables in order to ensure the accuracy of reliability analysis.Application of the proposed approach could provide a practical routine for mechanical design and manufactory to study the reliability and reliability-based sensitivity of basic design variables in mechanical reliability analysis and design.展开更多
We demonstrate two distinct emerging terahertz （THz） biomedical imaging techniques.One is based on the use of a new single frequency THz quantum cascade laser and the other is based on broadband THz time domain spec...We demonstrate two distinct emerging terahertz （THz） biomedical imaging techniques.One is based on the use of a new single frequency THz quantum cascade laser and the other is based on broadband THz time domain spectrocopy.The first method is employed to derive a metastasis lung tissue imaging at 3.7 THz with clear contrast between cancerous and healthy areas.The second approach is used to study an osseous tissue under several imaging modalities and achieve full THz spectroscopic imaging based on the frequency domain or on a fixed THz propagation time-delay.Sufficient contrast is achieved which facilitated the identification of regions with different cellular types and density compositions.展开更多
Over the last 50 years,the explosive adoption of modern agricultural practices has led to an enormous increase in the emission of non-biodegradable and highly biotoxic ions into the hydrosphere.Excess intake of such i...Over the last 50 years,the explosive adoption of modern agricultural practices has led to an enormous increase in the emission of non-biodegradable and highly biotoxic ions into the hydrosphere.Excess intake of such ions,even essential trace elements such as Cu^(2+)and F^(-),can have serious consequences on human health.Therefore,to ensure safe drinking water and regulate wastewater discharge,photoelectrochemical(PEC)online sensors were developed,with advantages such as low energy consumption,inherent miniaturization,simple instrumentation,and fast response.However,there is no publicly available systematic review of the recent advances in PEC ion sensors available in the literature since January 2017.Thus,this review covers the various strategies that have been used to enhance the sensitivity,selectivity,and limit of detection for PEC ion sensors.The photoelectrochemically active materials,conductive substrates,electronic transfer,and performance of various PEC sensors are discussed in detail and divided into sections based on the measurement principle and detected ion species.We conclude this review by highlighting the challenges and potential future avenues of research associated with the development of novel high-performance PEC sensors.展开更多
Prior to formation of the micelles of cationic surfactant (CSF), bromopyrogallol red (BPR) could exist in the forms of both monomer and oligomer After that, however, only BPR monomer existed. Nonionic surfactant OP-10...Prior to formation of the micelles of cationic surfactant (CSF), bromopyrogallol red (BPR) could exist in the forms of both monomer and oligomer After that, however, only BPR monomer existed. Nonionic surfactant OP-10 favoured the oligomerization of BPR monomer. The mixed micellar media prepared by mixing CSF and OP-10 in an appropriate ratio could be used for the sensitive and selective determination of Mo in Mo/W binary mixtures.展开更多
Fault diagnosis of fuel cells often focuses on single faults,leading to lower accuracy in diagnosing simultaneous faults.This paper researches a data-driven diagnostic method for both single and simultaneous faults,ai...Fault diagnosis of fuel cells often focuses on single faults,leading to lower accuracy in diagnosing simultaneous faults.This paper researches a data-driven diagnostic method for both single and simultaneous faults,aiming to establish an efficient online fault diagnosis approach.Firstly,a theoretical model of a proton exchange membrane fuel cell(PEMFC)system is established.Based on this,a radial basis function(RBF)neural network surrogate model is designed to improve computational efficiency.The average relative error across all features between the surrogate model and the theoretical model is below 1%.Subsequently,Sobol's global sensitivity analysis is used to analyse the relationship between PEMFC system faults and various characteristic parameters during real-time operation.The sensitive feature set related to different faults in the PEMFC system is then identified.Finally,an adaptive diagnostic strategy is proposed,and a sensitivity-based diagnostic algorithm is established.Compared with other common single-label and multi-label diagnostic methods,the sensitivity-based diagnostic algorithm achieves an F1_Score of 99.1%on single-fault data,cutting training time by more than 80%.In scenarios with simultaneous faults and sparse data,the method achieves an accuracy of 92.5%,which is 7.5%higher than that achieved by the best multi-label method.展开更多
To clarify the function effect of spectrum and linear polarization-coupled light on locusts’induction,determine the influence factors of linearly polarized light on locusts’polartactic characteristics,construct the ...To clarify the function effect of spectrum and linear polarization-coupled light on locusts’induction,determine the influence factors of linearly polarized light on locusts’polartactic characteristics,construct the technical characteristics of locusts’polarization induction,and develop locusts’polartactic induction photo-source,this study investigated the functional influence of spectral light and linear polarization-coupled light on locust phototactic and polartactic behavior.A linearly polarized light source system was used to determine the polartactic response of locusts induced by different linearly polarized vectors under normal light conditions.The results demonstrated that,within the context of spectral and linear polarization-coupled light,the visual response sensitivity of locusts was related to the spectral light intensity,being highest in response to orange light intensity.The visual aggregation and selective sensitivities of locusts were both influenced by spectral irradiation distance,with the violet spectrum inducing the strongest sensitivity in both cases.The polartactic chord function tuning response characteristics at different angles(0°-360°)were associated with linear polarization spectrum attributes.The polartactic response of locusts was related to changes in visual sensitivity resulting from the distance from the linear polarization light source,being optimal in response to the orange spectrum,whereas the violet spectrum induced the optimal visual and polartactic aggregation sensitivities.Furthermore,the specificity of chord function tuning response characteristics with periodic vector variations in a heterogeneous spectrum showed significant changes.An orange spectrum vector mode led to the most pronounced changes in response,whereas the violet spectrum vector mode exhibited the most significant changes in chord function properties.These variations in chord function and period induced by spectrum impacted the functional effect of linear polarization vector modes and reset the sensitive vector of locust polarization vision.Specifically,under the orange spectrum,locusts exhibited the highest polartactic response sensitivity at 330°vector,whereas,under the violet spectrum,the polartactic aggregation sensitivity was most pronounced at 30°vector,and visual trend sensitivity was optimal at 120°vector.Our results provide theoretical support for the study of the specific sensitivity nature of locust phototactic and polartactic behaviors,and the construction of a mechanism for inducing the polarization spectrum in locusts.展开更多
A new fluorescent probe RY was synthesized for the detection of Au3+ions based on a rhodamine B derivative.The fluorescent probe showed good selectivity and sensitivity to Au3+ions.Obvious color and fluorescence chang...A new fluorescent probe RY was synthesized for the detection of Au3+ions based on a rhodamine B derivative.The fluorescent probe showed good selectivity and sensitivity to Au3+ions.Obvious color and fluorescence changes could be observed with the naked eye while the fluorescent probe reacted with the Au3+ions.The detection limit of the probe was determined to be 36 ppb by the fluorescence titration.The excellent linear relationship suggests that the probe is potentially useful for quantitative detection of Au3+in vitro.We also demonstrated its bioimaging application in both living cells and mice.This was the first time that a fluorescent probe was successfully applied to imaging Au3+in living animals.展开更多
A new fluorescent probe, NPQ-C, was synthesized. NPQ-C was based on the naphthalimide derivatives and exhibited high selectivity and sensitivity for Cr3＋ ions. As a Cr3＋-amplified fluorescent probe, Its fluorescence...A new fluorescent probe, NPQ-C, was synthesized. NPQ-C was based on the naphthalimide derivatives and exhibited high selectivity and sensitivity for Cr3＋ ions. As a Cr3＋-amplified fluorescent probe, Its fluorescence spectrum showed 5.5-fold enhancement in the intensity of the signal at 500 nm on binding with the Cr3＋. Based on the fluorescence titration spectra and Job＇s-plot analysis, binding mode of NPQ-C with Cr3＋ was proposed. Fluorescence intensity was linear with concentration of Cr3＋ cation in a range from 0 to 10 μmol·L-1. NPQ-C was also sensitive for Cr3＋. The detection limit was calculated to be 0.20 pmol.L-1 which indicated that NPQ-C was sensitive to Cr3＋.展开更多
基金supported by Changjiang Scholars and Innovative Research Team in University of China (Grant No. IRT0816)Key National Science & Technology Special Project on "High-Grade CNC Machine Tools and Basic Manufacturing Equipments" of China (Grant No. 2010ZX04014-014)+1 种基金National Natural Science Foundation of China (Grant No. 50875039)Key Projects in National Science & Technology Pillar Program during the 11th Five-year Plan Period of China (Grant No. 2009BAG12A02-A07-2)
文摘The correlation coefficients of random variables of mechanical structures are generally chosen with experience or even ignored,which cannot actually reflect the effects of parameter uncertainties on reliability.To discuss the selection problem of the correlation coefficients from the reliability-based sensitivity point of view,the theory principle of the problem is established based on the results of the reliability sensitivity,and the criterion of correlation among random variables is shown.The values of the correlation coefficients are obtained according to the proposed principle and the reliability sensitivity problem is discussed.Numerical studies have shown the following results：（1） If the sensitivity value of correlation coefficient ρ is less than（at what magnitude 0.000 01）,then the correlation could be ignored,which could simplify the procedure without introducing additional error.（2） However,as the difference between ρs,that is the most sensitive to the reliability,and ρR,that is with the smallest reliability,is less than 0.001,ρs is suggested to model the dependency of random variables.This could ensure the robust quality of system without the loss of safety requirement.（3） In the case of ｜Eabs｜ρ0.001 and also ｜Erel｜ρ0.001,ρR should be employed to quantify the correlation among random variables in order to ensure the accuracy of reliability analysis.Application of the proposed approach could provide a practical routine for mechanical design and manufactory to study the reliability and reliability-based sensitivity of basic design variables in mechanical reliability analysis and design.
基金supported by the National Science Foundation,USA
文摘We demonstrate two distinct emerging terahertz （THz） biomedical imaging techniques.One is based on the use of a new single frequency THz quantum cascade laser and the other is based on broadband THz time domain spectrocopy.The first method is employed to derive a metastasis lung tissue imaging at 3.7 THz with clear contrast between cancerous and healthy areas.The second approach is used to study an osseous tissue under several imaging modalities and achieve full THz spectroscopic imaging based on the frequency domain or on a fixed THz propagation time-delay.Sufficient contrast is achieved which facilitated the identification of regions with different cellular types and density compositions.
基金financial support from the National Natural Science Foundation of China(NSFC,Nos.52176178,51876018)Innovation Research Group of Universities in Chongqing(No.CXQT21035)+1 种基金Scientific and Technological Research Program of Chongqing Municipal Education Commission of China(No.KJZDM202201101)Chongqing Postgraduate Innovation Project(No.CYS22645)。
文摘Over the last 50 years,the explosive adoption of modern agricultural practices has led to an enormous increase in the emission of non-biodegradable and highly biotoxic ions into the hydrosphere.Excess intake of such ions,even essential trace elements such as Cu^(2+)and F^(-),can have serious consequences on human health.Therefore,to ensure safe drinking water and regulate wastewater discharge,photoelectrochemical(PEC)online sensors were developed,with advantages such as low energy consumption,inherent miniaturization,simple instrumentation,and fast response.However,there is no publicly available systematic review of the recent advances in PEC ion sensors available in the literature since January 2017.Thus,this review covers the various strategies that have been used to enhance the sensitivity,selectivity,and limit of detection for PEC ion sensors.The photoelectrochemically active materials,conductive substrates,electronic transfer,and performance of various PEC sensors are discussed in detail and divided into sections based on the measurement principle and detected ion species.We conclude this review by highlighting the challenges and potential future avenues of research associated with the development of novel high-performance PEC sensors.
文摘Prior to formation of the micelles of cationic surfactant (CSF), bromopyrogallol red (BPR) could exist in the forms of both monomer and oligomer After that, however, only BPR monomer existed. Nonionic surfactant OP-10 favoured the oligomerization of BPR monomer. The mixed micellar media prepared by mixing CSF and OP-10 in an appropriate ratio could be used for the sensitive and selective determination of Mo in Mo/W binary mixtures.
基金supported by the National Natural Science Foundation of China(Grant No.51905217)the Carbon Peak and Carbon Neutral Technology Innovation Fund Project of Jiangsu Province(Grant No.BE2023091-1)+1 种基金the International Postdoctoral Exchange Fellowship Program from China Postdoctoral Council(Grant No.PC2021032)the State Scholarship Fund from the China Scholarship Council。
文摘Fault diagnosis of fuel cells often focuses on single faults,leading to lower accuracy in diagnosing simultaneous faults.This paper researches a data-driven diagnostic method for both single and simultaneous faults,aiming to establish an efficient online fault diagnosis approach.Firstly,a theoretical model of a proton exchange membrane fuel cell(PEMFC)system is established.Based on this,a radial basis function(RBF)neural network surrogate model is designed to improve computational efficiency.The average relative error across all features between the surrogate model and the theoretical model is below 1%.Subsequently,Sobol's global sensitivity analysis is used to analyse the relationship between PEMFC system faults and various characteristic parameters during real-time operation.The sensitive feature set related to different faults in the PEMFC system is then identified.Finally,an adaptive diagnostic strategy is proposed,and a sensitivity-based diagnostic algorithm is established.Compared with other common single-label and multi-label diagnostic methods,the sensitivity-based diagnostic algorithm achieves an F1_Score of 99.1%on single-fault data,cutting training time by more than 80%.In scenarios with simultaneous faults and sparse data,the method achieves an accuracy of 92.5%,which is 7.5%higher than that achieved by the best multi-label method.
基金supported by the Scientific and Technological Project of Henan Province,China(Grant No.242102111179,222102210116,222102320080)he Natural Science Foundation Project of Henan Province,China(Grant No.232300420024).
文摘To clarify the function effect of spectrum and linear polarization-coupled light on locusts’induction,determine the influence factors of linearly polarized light on locusts’polartactic characteristics,construct the technical characteristics of locusts’polarization induction,and develop locusts’polartactic induction photo-source,this study investigated the functional influence of spectral light and linear polarization-coupled light on locust phototactic and polartactic behavior.A linearly polarized light source system was used to determine the polartactic response of locusts induced by different linearly polarized vectors under normal light conditions.The results demonstrated that,within the context of spectral and linear polarization-coupled light,the visual response sensitivity of locusts was related to the spectral light intensity,being highest in response to orange light intensity.The visual aggregation and selective sensitivities of locusts were both influenced by spectral irradiation distance,with the violet spectrum inducing the strongest sensitivity in both cases.The polartactic chord function tuning response characteristics at different angles(0°-360°)were associated with linear polarization spectrum attributes.The polartactic response of locusts was related to changes in visual sensitivity resulting from the distance from the linear polarization light source,being optimal in response to the orange spectrum,whereas the violet spectrum induced the optimal visual and polartactic aggregation sensitivities.Furthermore,the specificity of chord function tuning response characteristics with periodic vector variations in a heterogeneous spectrum showed significant changes.An orange spectrum vector mode led to the most pronounced changes in response,whereas the violet spectrum vector mode exhibited the most significant changes in chord function properties.These variations in chord function and period induced by spectrum impacted the functional effect of linear polarization vector modes and reset the sensitive vector of locust polarization vision.Specifically,under the orange spectrum,locusts exhibited the highest polartactic response sensitivity at 330°vector,whereas,under the violet spectrum,the polartactic aggregation sensitivity was most pronounced at 30°vector,and visual trend sensitivity was optimal at 120°vector.Our results provide theoretical support for the study of the specific sensitivity nature of locust phototactic and polartactic behaviors,and the construction of a mechanism for inducing the polarization spectrum in locusts.
基金supported financially by the National Natural Science Foundation of China(21222605,21006009,21136002,21376039)the Fundamental Research Funds for the Central Universities of China+1 种基金the Program for New Century Excellent Talents in Universitythe project sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Education
文摘A new fluorescent probe RY was synthesized for the detection of Au3+ions based on a rhodamine B derivative.The fluorescent probe showed good selectivity and sensitivity to Au3+ions.Obvious color and fluorescence changes could be observed with the naked eye while the fluorescent probe reacted with the Au3+ions.The detection limit of the probe was determined to be 36 ppb by the fluorescence titration.The excellent linear relationship suggests that the probe is potentially useful for quantitative detection of Au3+in vitro.We also demonstrated its bioimaging application in both living cells and mice.This was the first time that a fluorescent probe was successfully applied to imaging Au3+in living animals.
基金The authors gratefully acknowledge the National Nature Science Foundation of China，the support from the Fundamental Research Funds for the Central Universities,the Opening Foundation of Zhejiang Provincial Top Key Discipline,and Baihehua Group
文摘A new fluorescent probe, NPQ-C, was synthesized. NPQ-C was based on the naphthalimide derivatives and exhibited high selectivity and sensitivity for Cr3＋ ions. As a Cr3＋-amplified fluorescent probe, Its fluorescence spectrum showed 5.5-fold enhancement in the intensity of the signal at 500 nm on binding with the Cr3＋. Based on the fluorescence titration spectra and Job＇s-plot analysis, binding mode of NPQ-C with Cr3＋ was proposed. Fluorescence intensity was linear with concentration of Cr3＋ cation in a range from 0 to 10 μmol·L-1. NPQ-C was also sensitive for Cr3＋. The detection limit was calculated to be 0.20 pmol.L-1 which indicated that NPQ-C was sensitive to Cr3＋.
