Ignoring the influence of flow velocity and flow temperature on muffling performance,performance tests were conducted without airflow in the development phase of the muffler which accounts to the difficulty of obtaini...Ignoring the influence of flow velocity and flow temperature on muffling performance,performance tests were conducted without airflow in the development phase of the muffler which accounts to the difficulty of obtaining a perfect match between the actual noise reduction effect and the design goal.Based on the two-load test theory,a set of high-temperature and high-speed airflow simulation measurement devices for the muffler has been built.In order to avoid the impact of high-temperature and high-speed airflow on the sensor,a high temperature resistant sensor holder has been designed for the test rig.The sound pressure has been measured in the pipe by using the lead-out measurement.In addition,a variable impedance load is placed at the end of the test tube to realize the switch between two different impedance loads by the wave handle of the variable impedance load.A sound source correction method is proposed to decrease the random fluctuation of the spectral characteristics of the output noise signal,which is caused by the acoustic impedance variation at the connection between the transition pipeline and the combined sound source system.Finally,an acoustic software has been used to calculate the transmission loss of the muffler in the presence of high temperature airflow.In comparing the experimental measurements and the simulation results,the small difference shows that:the bench not only can effectively simulate high-temperature and flow velocity environment of the engine but also accurately test the transmission loss of the muffler.展开更多
There is a bottleneck in the design of vehicle sound that the subjective perception of sound quality that combines multiple psychological factors fails to be accurately and objectively quantified.Therefore,EEG signals...There is a bottleneck in the design of vehicle sound that the subjective perception of sound quality that combines multiple psychological factors fails to be accurately and objectively quantified.Therefore,EEG signals are introduced in this paper to investigate the evaluation and design method of vehicle acceleration sound with powerful sound quality.Firstly,the experiment of EEG acquisition and subjective evaluation under the stimulation of powerful vehicle sounds is conducted,respectively,then three physiological EEG features of PSD_β,PSD_γand DE are constructed to evaluate the vehicle sounds based on the correlation analysis algorithms.Subsequently,the Adaptive Genetic Algorithm(AGA)is proposed to optimize the Elman model,where an intelligent model(AGA–Elman)is constructed to objectively predicate the perception of subjects for the vehicle sounds with powerful sound quality.The results demonstrate that the error of the constructed AGA–Elman model is only 2.88%,which outperforms than the traditional BP and Elman model;Finally,two vehicle acceleration sounds(Design1 and Design2)are designed based on the constructed AGA–Elman model from the perspective of order modulation and frequency modulation,which provide the acoustic theoretical guidance for the design of vehicle sound incorporating the EEG signals.展开更多
Erratumto:Journal of Bionic Engineering(2023)20:338-348 https:/doi.0rg/10.1007/s42235-022-00247-4 In Table 1,the value of Mesh's Feature dimensions(mm)"0.42"should have read"0.04".The original ...Erratumto:Journal of Bionic Engineering(2023)20:338-348 https:/doi.0rg/10.1007/s42235-022-00247-4 In Table 1,the value of Mesh's Feature dimensions(mm)"0.42"should have read"0.04".The original article has been corrected.展开更多
Solid–liquid separation is widely used in daily life and practical engineering.Traditional industrial filters are prone to clogging,but this rarely occurs in filter-feeding organisms.Inspired by the filter feeding me...Solid–liquid separation is widely used in daily life and practical engineering.Traditional industrial filters are prone to clogging,but this rarely occurs in filter-feeding organisms.Inspired by the filter feeding mechanism of balaenid whales and considering the local grooves in the fringes layer,a new bionic filter is produced by 3D printing technology through the bionic design of the parallel channels inside the mouth of balaenid whales.At the same time,a test platform composed of the bionic filter,peristaltic pump,fluid pulse rectifier and water tank is built to carry out the fluid flow pattern dyeing and particle filtration experiments.It is found that fluid separation occurs near the groove structure and local vortices are generated.The vortex control filtration mechanism makes the particles in the front grooves tend to accumulate on the left side,which has a certain anti-clogging effect.Moreover,the increase of flow velocity leads to the enhancement of vortices,which makes the accumulation effect on the left more obvious.This study initially practices the bionic application from biological model to engineering design,and the vortex control anti-clogging filtration mechanism proposed in the study has a wide range of application prospects and values.展开更多
Leaf nitrogen,phosphorus,and potassium content(LNC,LPC,LKC)are core nutrient elements and measurable trait parameters essential for assessing vegetation growth status and understanding hydrology-vegetation in-teractio...Leaf nitrogen,phosphorus,and potassium content(LNC,LPC,LKC)are core nutrient elements and measurable trait parameters essential for assessing vegetation growth status and understanding hydrology-vegetation in-teractions.However,the spectral characteristics of these elements remain poorly understood,posing a significant challenge for quantitative remote sensing inversion.This study analyzed 303 samples and 21,210 full-spectrum hyperspectral measurements across seven vegetation species,revealing inherent interspecific heterogeneity in their spectra.We quantified spectral heterogeneity using Enhanced Spectral Information Divergence(ESID)and developed a novel r-Enhanced Wavelet Two-Dimensional Correlation Spectroscopy(rEW-2DCOS)method to identify spectral bands exhibiting synergistic correlations with each nutrient element.Validation against tradi-tional CSPA and full-spectrum data confirmed the method's feasibility.The results revealed the density peaks of sensitive bands for LNC(600-860 nm,1230 nm,2080-2250 nm),LPC(600-750 nm,1930-2380 nm),and LKC(580-830 nm,1680-2350 nm).Furthermore,we established a mechanism-guided adaptive ensemble learning regression model(M-AEL)for inversion.The average inversion accuracy(R^(2))using rEW-2DCOS reached 0.71 for LNC,0.73 for LPC,and 0.71 for LKC across the seven vegetation species,representing improvements of 14.6%,14.9%,and 3.1%over CSPA-based results and 83.3%,83.8%,and 88.7%over full-spectrum results.Finally,the Mantel test assessed relationships between LNC,LPC,LKC,and hydrology-vegetation factors across species,identifying key drivers for each element.This research advances hyperspectral remote sensing for estimating key nutrient elements in karst wetlands,providing a scientific foundation for monitoring vegetation health and maintaining the equilibrium within these fragile hydrology-vegetation ecosystems.展开更多
基金Supported by National Key Research and Development Program(2016YFD0700704B)。
文摘Ignoring the influence of flow velocity and flow temperature on muffling performance,performance tests were conducted without airflow in the development phase of the muffler which accounts to the difficulty of obtaining a perfect match between the actual noise reduction effect and the design goal.Based on the two-load test theory,a set of high-temperature and high-speed airflow simulation measurement devices for the muffler has been built.In order to avoid the impact of high-temperature and high-speed airflow on the sensor,a high temperature resistant sensor holder has been designed for the test rig.The sound pressure has been measured in the pipe by using the lead-out measurement.In addition,a variable impedance load is placed at the end of the test tube to realize the switch between two different impedance loads by the wave handle of the variable impedance load.A sound source correction method is proposed to decrease the random fluctuation of the spectral characteristics of the output noise signal,which is caused by the acoustic impedance variation at the connection between the transition pipeline and the combined sound source system.Finally,an acoustic software has been used to calculate the transmission loss of the muffler in the presence of high temperature airflow.In comparing the experimental measurements and the simulation results,the small difference shows that:the bench not only can effectively simulate high-temperature and flow velocity environment of the engine but also accurately test the transmission loss of the muffler.
基金supported by the National Natural Science Foundation of China(No.52272389)the National Natural Science Foundation of China(No.52175111).
文摘There is a bottleneck in the design of vehicle sound that the subjective perception of sound quality that combines multiple psychological factors fails to be accurately and objectively quantified.Therefore,EEG signals are introduced in this paper to investigate the evaluation and design method of vehicle acceleration sound with powerful sound quality.Firstly,the experiment of EEG acquisition and subjective evaluation under the stimulation of powerful vehicle sounds is conducted,respectively,then three physiological EEG features of PSD_β,PSD_γand DE are constructed to evaluate the vehicle sounds based on the correlation analysis algorithms.Subsequently,the Adaptive Genetic Algorithm(AGA)is proposed to optimize the Elman model,where an intelligent model(AGA–Elman)is constructed to objectively predicate the perception of subjects for the vehicle sounds with powerful sound quality.The results demonstrate that the error of the constructed AGA–Elman model is only 2.88%,which outperforms than the traditional BP and Elman model;Finally,two vehicle acceleration sounds(Design1 and Design2)are designed based on the constructed AGA–Elman model from the perspective of order modulation and frequency modulation,which provide the acoustic theoretical guidance for the design of vehicle sound incorporating the EEG signals.
文摘Erratumto:Journal of Bionic Engineering(2023)20:338-348 https:/doi.0rg/10.1007/s42235-022-00247-4 In Table 1,the value of Mesh's Feature dimensions(mm)"0.42"should have read"0.04".The original article has been corrected.
基金supports from the National Natural Science Foundation of China(51775169)the High Level Talent Foundation of Henan University of Technology(31401456)the Innovative Funds Plan of Henan University of Technology(2020ZKCJ26)are gratefully acknowledged.
文摘Solid–liquid separation is widely used in daily life and practical engineering.Traditional industrial filters are prone to clogging,but this rarely occurs in filter-feeding organisms.Inspired by the filter feeding mechanism of balaenid whales and considering the local grooves in the fringes layer,a new bionic filter is produced by 3D printing technology through the bionic design of the parallel channels inside the mouth of balaenid whales.At the same time,a test platform composed of the bionic filter,peristaltic pump,fluid pulse rectifier and water tank is built to carry out the fluid flow pattern dyeing and particle filtration experiments.It is found that fluid separation occurs near the groove structure and local vortices are generated.The vortex control filtration mechanism makes the particles in the front grooves tend to accumulate on the left side,which has a certain anti-clogging effect.Moreover,the increase of flow velocity leads to the enhancement of vortices,which makes the accumulation effect on the left more obvious.This study initially practices the bionic application from biological model to engineering design,and the vortex control anti-clogging filtration mechanism proposed in the study has a wide range of application prospects and values.
基金supported by the National Natural Science Foundation of China(Grant number 42371341)the Natural Science Foundation of Guangxi Zhuang Autonomous Region(CN)(Grant number 2025GXNSFFA069008,2024GXNSFAA010351)+1 种基金the Key Laboratory of Tropical Marine Ecosystem and Bioresource,Ministry of Natural Resources(Grant Number 2023ZD02)the Innovation Project of Guangxi Graduate Education(Grant Number YCSW2025397).
文摘Leaf nitrogen,phosphorus,and potassium content(LNC,LPC,LKC)are core nutrient elements and measurable trait parameters essential for assessing vegetation growth status and understanding hydrology-vegetation in-teractions.However,the spectral characteristics of these elements remain poorly understood,posing a significant challenge for quantitative remote sensing inversion.This study analyzed 303 samples and 21,210 full-spectrum hyperspectral measurements across seven vegetation species,revealing inherent interspecific heterogeneity in their spectra.We quantified spectral heterogeneity using Enhanced Spectral Information Divergence(ESID)and developed a novel r-Enhanced Wavelet Two-Dimensional Correlation Spectroscopy(rEW-2DCOS)method to identify spectral bands exhibiting synergistic correlations with each nutrient element.Validation against tradi-tional CSPA and full-spectrum data confirmed the method's feasibility.The results revealed the density peaks of sensitive bands for LNC(600-860 nm,1230 nm,2080-2250 nm),LPC(600-750 nm,1930-2380 nm),and LKC(580-830 nm,1680-2350 nm).Furthermore,we established a mechanism-guided adaptive ensemble learning regression model(M-AEL)for inversion.The average inversion accuracy(R^(2))using rEW-2DCOS reached 0.71 for LNC,0.73 for LPC,and 0.71 for LKC across the seven vegetation species,representing improvements of 14.6%,14.9%,and 3.1%over CSPA-based results and 83.3%,83.8%,and 88.7%over full-spectrum results.Finally,the Mantel test assessed relationships between LNC,LPC,LKC,and hydrology-vegetation factors across species,identifying key drivers for each element.This research advances hyperspectral remote sensing for estimating key nutrient elements in karst wetlands,providing a scientific foundation for monitoring vegetation health and maintaining the equilibrium within these fragile hydrology-vegetation ecosystems.
