A hybrid image allows multiple image interpretations to be modulated by the viewing distance.Originally,it can be constructed by combining the low and high spatial frequencies of two different images.The original hybr...A hybrid image allows multiple image interpretations to be modulated by the viewing distance.Originally,it can be constructed by combining the low and high spatial frequencies of two different images.The original hybrid image synthesis was limited to similar shapes of source images that were aligned in the edges,e.g.,faces with a different expression,to produce an effective double image interpretation.In our previous work,we proposed a noiseinserted method for synthesizing a hybrid image from dissimilar shape images or unaligned images.In this work,we propose a novel method for adding an image to be seen from a middle viewing distance.The middlefrequency(MF)image is extracted by a special bandpass filter,which generates ringing while extracting only specified frequency bands.With this method,the middle frequency should be perceived as a meaningless pattern when viewed from a far distance and close up.A parameter tuning experiment was performed to determine the suitable cutoff frequencies for designing the filter for the MF image.We found that ringings of a suitable size could be used to make the middle frequency less noticeable when seen from far away.展开更多
Eco-friendly SnTe based thermoelectric materials are intensively studied recently as candidates to replace PbTe;yet the thermoelectric performance of SnTe is suppressed by its intrinsically high carrier concentration ...Eco-friendly SnTe based thermoelectric materials are intensively studied recently as candidates to replace PbTe;yet the thermoelectric performance of SnTe is suppressed by its intrinsically high carrier concentration and high thermal conductivity.In this work,we confirm that the Ag and La co-doping can be applied to simultaneously enhance the power factor and reduce the thermal conductivity,contributing to a final promotion of figure of merit.On one hand,the carrier concentration and band offset between valence bands are concurrently reduced,promoting the power factor to a highest value of-2436μW·m^(-1)·K^(-2) at 873 K.On the other hand,lots of dislocations(~3.16×10^(7)mm^(-2))associated with impurity precipitates are generated,resulting in the decline of thermal conductivity to a minimum value of 1.87 W·m^(-1)·K^(-1) at 873 K.As a result,a substantial thermoelectric performance enhancement up to zT≈1.0 at 873 K is obtained for the sample Sn0.94Ag0.09La0.05Te,which is twice that of the pristine SnTe(zT≈0.49 at 873 K).This strategy of synergistic manipulation of electronic band and microstructures via introducing rare earth elements could be applied to other systems to improve thermoelectric performance.展开更多
In this study,a micro in-plane p-type thermoelectric generator(TEG),which consists of thin-film Si_(1-x-y)Ge_(x)Sn_(y) ternary alloy semiconductor on insulator,is developed to make efficient use of waste heat such as ...In this study,a micro in-plane p-type thermoelectric generator(TEG),which consists of thin-film Si_(1-x-y)Ge_(x)Sn_(y) ternary alloy semiconductor on insulator,is developed to make efficient use of waste heat such as human body.A power factor value as high as 1095 mWm^(-1) K^(-2) had been achieved using Bion implanted and short-term rapid thermal annealing(RTA)process.In addition,a measuring scheme for micro TEG without external load resistance was designed.In one measuring session,multiple parameters can be measured.The micro single-arm TEG prepared by semiconductor process can output 0.29 nW power at a temperature difference of 15 K,and a cross-sectional power density has reached up to 0.58 mW/cm^(2),which is a superior value for wearable device.The findings of this study have important reference value for wearable device performance improvement and output power measuring of micro TEG.展开更多
文摘A hybrid image allows multiple image interpretations to be modulated by the viewing distance.Originally,it can be constructed by combining the low and high spatial frequencies of two different images.The original hybrid image synthesis was limited to similar shapes of source images that were aligned in the edges,e.g.,faces with a different expression,to produce an effective double image interpretation.In our previous work,we proposed a noiseinserted method for synthesizing a hybrid image from dissimilar shape images or unaligned images.In this work,we propose a novel method for adding an image to be seen from a middle viewing distance.The middlefrequency(MF)image is extracted by a special bandpass filter,which generates ringing while extracting only specified frequency bands.With this method,the middle frequency should be perceived as a meaningless pattern when viewed from a far distance and close up.A parameter tuning experiment was performed to determine the suitable cutoff frequencies for designing the filter for the MF image.We found that ringings of a suitable size could be used to make the middle frequency less noticeable when seen from far away.
基金supported by National Natural Science Foundation of China(Grant Nos.51801040,51961011,51772056)Guangxi Natural Science Foundation of China(Grant Nos.2020GXNSFAA159111,AD20159006,2018GXNSFAA294135,2018JJA160257,and 2019GXNSFBA245028).
文摘Eco-friendly SnTe based thermoelectric materials are intensively studied recently as candidates to replace PbTe;yet the thermoelectric performance of SnTe is suppressed by its intrinsically high carrier concentration and high thermal conductivity.In this work,we confirm that the Ag and La co-doping can be applied to simultaneously enhance the power factor and reduce the thermal conductivity,contributing to a final promotion of figure of merit.On one hand,the carrier concentration and band offset between valence bands are concurrently reduced,promoting the power factor to a highest value of-2436μW·m^(-1)·K^(-2) at 873 K.On the other hand,lots of dislocations(~3.16×10^(7)mm^(-2))associated with impurity precipitates are generated,resulting in the decline of thermal conductivity to a minimum value of 1.87 W·m^(-1)·K^(-1) at 873 K.As a result,a substantial thermoelectric performance enhancement up to zT≈1.0 at 873 K is obtained for the sample Sn0.94Ag0.09La0.05Te,which is twice that of the pristine SnTe(zT≈0.49 at 873 K).This strategy of synergistic manipulation of electronic band and microstructures via introducing rare earth elements could be applied to other systems to improve thermoelectric performance.
基金supported by PRESTO(Grant No.JPMJPR15R2)and CREST(Grant No.JPMJCR19Q5)from the JST in Japan,a research grant(Creation of Life Innovation Materials for Interdisciplinary and International Researcher Development)from the MEXT in Japan,the National Natural Science Foundation of China(Grant Nos.51772056,51961011,52061009)+2 种基金National Key Research and Development Program of China(No.2017YFE0198000)Guangxi Natural Science Foundation of China(Grant No.2019GXNSFAA245039,2017 GXNSFFA198015)the open foundation of Guangxi Key laboratory of Processing for Nonferrous Metals and Featured Materials,Guangxi University(Grant No.2020GXYSOF11).
文摘In this study,a micro in-plane p-type thermoelectric generator(TEG),which consists of thin-film Si_(1-x-y)Ge_(x)Sn_(y) ternary alloy semiconductor on insulator,is developed to make efficient use of waste heat such as human body.A power factor value as high as 1095 mWm^(-1) K^(-2) had been achieved using Bion implanted and short-term rapid thermal annealing(RTA)process.In addition,a measuring scheme for micro TEG without external load resistance was designed.In one measuring session,multiple parameters can be measured.The micro single-arm TEG prepared by semiconductor process can output 0.29 nW power at a temperature difference of 15 K,and a cross-sectional power density has reached up to 0.58 mW/cm^(2),which is a superior value for wearable device.The findings of this study have important reference value for wearable device performance improvement and output power measuring of micro TEG.
