In dry-coupled ultrasonic thickness measurement,thick rubber layers introduce high-amplitude parasitic echoes that obscure defect signals and degrade thickness accuracy.Existing methods struggle to resolve overlap-pin...In dry-coupled ultrasonic thickness measurement,thick rubber layers introduce high-amplitude parasitic echoes that obscure defect signals and degrade thickness accuracy.Existing methods struggle to resolve overlap-ping echoes under variable coupling conditions and non-stationary noise.This study proposes a novel dual-criterion framework integrating energy contribution and statistical impulsivity metrics to isolate specimen re-flections from coupling-layer interference.By decomposing A-scan signals into Intrinsic Mode Functions(IMFs),the framework employs energy contribution thresholds(>85%)and kurtosis indices(>3)to autonomously select IMFs containing valid specimen echoes.Hybrid time-frequency thresholding further suppresses interference through amplitude filtering and spectral focusing.Experimental results demonstrate the framework’s robustness,achieving 92.3%thickness accuracy for 5 mm steel specimens with 5 mm rubber coupling,outperforming conventional methods by up to 18.7%.The dual-criterion approach reduces operator dependency by 37%and maintainsΔT<0.03 mm under surface roughness up to 6.3μm,offering a practical solution for industrial nondestructive testing with thick dry-coupled interfaces.展开更多
Developing effective,versatile,and high-precision sensing interfaces remains a crucial challenge in human-machine-environment interaction applications.Despite progress in interaction-oriented sensing skins,limitations...Developing effective,versatile,and high-precision sensing interfaces remains a crucial challenge in human-machine-environment interaction applications.Despite progress in interaction-oriented sensing skins,limitations remain in unit-level reconfiguration,multiaxial force and motion sensing,and robust operation across dynamically changing or irregular surfaces.Herein,we develop a reconfigurable omnidirectional triboelectric whisker sensor array(RO-TWSA)comprising multiple sensing units that integrate a triboelectric whisker structure(TWS)with an untethered hydro-sealing vacuum sucker(UHSVS),enabling reversibly portable deployment and omnidirectional perception across diverse surfaces.Using a simple dual-triangular electrode layout paired with MXene/silicone nanocomposite dielectric layer,the sensor unit achieves precise omnidirectional force and motion sensing with a detection threshold as low as 0.024 N and an angular resolution of 5°,while the UHSVS provides reliable and reversible multi-surface anchoring for the sensor units by involving a newly designed hydrogel combining high mechanical robustness and superior water absorption.Extensive experiments demonstrate the effectiveness of RO-TWSA across various interactive scenarios,including teleoperation,tactile diagnostics,and robotic autonomous exploration.Overall,RO-TWSA presents a versatile and high-resolution tactile interface,offering new avenues for intelligent perception and interaction in complex real-world environments.展开更多
Catalytic hydrodeoxygenation(HDO)of biomass-derived oxy-compounds to advanced hydrocarbon fuels usually requires bifunctional catalysts containing metals and acidic sites.The appropriate tuning of metal and/or acidic ...Catalytic hydrodeoxygenation(HDO)of biomass-derived oxy-compounds to advanced hydrocarbon fuels usually requires bifunctional catalysts containing metals and acidic sites.The appropriate tuning of metal and/or acidic active sites at interfaces of bifunctional catalysts can significantly improve catalyst activity and product selectivity.Here,4-trifuoromethyl salicylic acid(TFMSA),as a hydrothermal stable organic acid,was employed to tailor the bifunctional interface of Ru/γ-Al_(2)O_(3)to enhance the catalytic performance on converting lignin-derived phenols to jet fuel range cycloalkanes.More than 80%phenol was converted into cyclohexane at 230°C for 1 h over Ru/γ-Al_(2)O_(3)modified by TFMSA,which was about three times higher than that over unmodified Ru/γ-Al_(2)O_(3).X-ray diffraction(XRD),Transmission electron microscope(TEM),H2 chemisorption,and energy dispersive X-ray spectroscopy(EDS)elemental mapping results indicated that Ru nanoparticles and TFMSA were well distributed onγ-Al_(2)O_(3),and a nanoscale intimacy between Ru and TFMSA was reached.Meanwhile,Fourier transform infrared spectroscopy after pyridine adsorption(Py-FT-IR)analysis proved that Brønsted acidic sites on the catalytic interfaces of TFMSA modified Ru/γ-Al_(2)O_(3)had been improved.Moreover,the kinetic and density functional theory(DFT)results suggested that the synergistic effects of adjacent Ru nanoparticles and acidic sites were crutial for promoting the rate-limiting conversion step of phenol HDO to cyclohexane.展开更多
Optimizing the intrinsic activity of non-noble metal by precisely tailoring electronic structure offers an appealing way to construct cost-effective catalysts for selective biomass valorization.Herein,we reported a P-...Optimizing the intrinsic activity of non-noble metal by precisely tailoring electronic structure offers an appealing way to construct cost-effective catalysts for selective biomass valorization.Herein,we reported a P-doping bifunctional catalyst(Ni-P/mSiO_(2))that achieved 96.6%yield for the hydrogenation rearrangement of furfural to cyclopentanone at mild conditions(1 MPaH_(2),150°C).The turnover frequency of Ni-P/mSiO_(2)was 411.9 h^(-1),which was 3.2-fold than that of Ni/mSiO_(2)(127.2 h^(-1)).Detailed characterizations and differential charge density calculations revealed that the electron-deficient Niδ+species were generated by the electron transfer from Ni to P,which promoted the ring rearrangement reaction.Density functional theory calculations illustrated that the presence of P atoms endowed furfural tilted adsorb on the Ni surface by the C=O group and facilitated the desorption of cyclopentanone.This work unraveled the connection between the localized electronic structures and the catalytic properties,so as to provide a promising reference for designing advanced catalysts for biomass valorization.展开更多
In this paper,we consider the difference properties of Riordan arrays.As their applications,we provide some difference identities involving several classical combinatorial sequences such as the generalized Stirling nu...In this paper,we consider the difference properties of Riordan arrays.As their applications,we provide some difference identities involving several classical combinatorial sequences such as the generalized Stirling numbers,including Stirling numbers of the first and second kinds and Stirling numbers of type B of the first and second kinds,and Gegenbauer-Humbert-type polynomials.展开更多
The bottom-up construction of self-powered artificial cells is significant to understand the energy supply and metabolism of nature cells.Here,we demonstrate an efficient manner to build thylakoid-containing artificia...The bottom-up construction of self-powered artificial cells is significant to understand the energy supply and metabolism of nature cells.Here,we demonstrate an efficient manner to build thylakoid-containing artificial cells,which continuously convert light energy into chemical energy to supply adenosine 5'-triphosphate(ATP)under light illumination.The production of ATP supplies energy to promote the biological enzyme cascade reactions,where glucose is transformed into glucose 6-phosphate(G6P)under the catalysis of hexokinase(HK).G6P was further converted to gluconolactone 6-phosphate(PG)in the presence of 6-phosphate dehydrogenase(G6PDH),meanwhile NADP^(+) was converted to nicotinamide adenine dinucleotide phosphate(NADPH).The self-powered artificial cells were demonstrated to generate ATP and NADPH successively,which provided a way for building more complicated artificial cells.展开更多
基金funded by the National Natural Science Foundation of China,grant number U24A20135Inner Mongolia Natural Science Foundation major project,grant number 2023ZD12+7 种基金Inner Mongolia Autonomous Region key research and development and achievement transformation plan project,grant number 2023YFHH0090Natural Science Foundation of Inner Mongolia,grant number 2022MS05006Inner Mongolia Autonomous Region Talent Development FundUniversity basic research business expenses,grant number 2023RCTD012University basic research business expenses,grant number 2023QNJS075Postgraduate Research Innovation Program and of Inner Mongolia Autonomous Region,grant number KC2024053BUniversity basic research business expenses,grant number 2024YXXS012National Key Laboratory of Special Vehicle Design and Manufacturing Integration Technology,grant number GZ2023KF012.
文摘In dry-coupled ultrasonic thickness measurement,thick rubber layers introduce high-amplitude parasitic echoes that obscure defect signals and degrade thickness accuracy.Existing methods struggle to resolve overlap-ping echoes under variable coupling conditions and non-stationary noise.This study proposes a novel dual-criterion framework integrating energy contribution and statistical impulsivity metrics to isolate specimen re-flections from coupling-layer interference.By decomposing A-scan signals into Intrinsic Mode Functions(IMFs),the framework employs energy contribution thresholds(>85%)and kurtosis indices(>3)to autonomously select IMFs containing valid specimen echoes.Hybrid time-frequency thresholding further suppresses interference through amplitude filtering and spectral focusing.Experimental results demonstrate the framework’s robustness,achieving 92.3%thickness accuracy for 5 mm steel specimens with 5 mm rubber coupling,outperforming conventional methods by up to 18.7%.The dual-criterion approach reduces operator dependency by 37%and maintainsΔT<0.03 mm under surface roughness up to 6.3μm,offering a practical solution for industrial nondestructive testing with thick dry-coupled interfaces.
基金supported by the National Natural Science Foundation of China(General Program)under Grant 52571385National Key R&D Program of China(Grant No.2024YFC2815000 and No.2024YFB3816000)+12 种基金Open Fund of State Key Laboratory of Deep-sea Manned Vehicles(Grant No.2025SKLDMV07)Shenzhen Science and Technology Program(WDZC20231128114452001,JCYJ20240813112107010 and JCYJ20240813111910014)the Tsinghua SIGS Scientific Research Startup Fund(QD2022021C)the Dreams Foundation of Jianghuai Advance Technology Center(2023-ZM 01 Z006)the Ocean Decade International Cooperation Center(ODCC)(GHZZ3702840002024020000026)Shenzhen Key Laboratory of Advanced Technology for Marine Ecology(ZDSYS20230626091459009)Shenzhen Science and Technology Program(No.KJZD20240903100905008)the National Natural Science Foundation of China(No.22305141)Pearl River Talent Program(No.2023QN10C114)General Program of Guangdong Province(No.2025A1515011700)the Guangdong Innovative and Entrepreneurial Research Team Program(2023ZT10C040)Scientific Research Foundation from Shenzhen Finance Bureau(No.GJHZ20240218113600002)Tsinghua University(JC2023001).
文摘Developing effective,versatile,and high-precision sensing interfaces remains a crucial challenge in human-machine-environment interaction applications.Despite progress in interaction-oriented sensing skins,limitations remain in unit-level reconfiguration,multiaxial force and motion sensing,and robust operation across dynamically changing or irregular surfaces.Herein,we develop a reconfigurable omnidirectional triboelectric whisker sensor array(RO-TWSA)comprising multiple sensing units that integrate a triboelectric whisker structure(TWS)with an untethered hydro-sealing vacuum sucker(UHSVS),enabling reversibly portable deployment and omnidirectional perception across diverse surfaces.Using a simple dual-triangular electrode layout paired with MXene/silicone nanocomposite dielectric layer,the sensor unit achieves precise omnidirectional force and motion sensing with a detection threshold as low as 0.024 N and an angular resolution of 5°,while the UHSVS provides reliable and reversible multi-surface anchoring for the sensor units by involving a newly designed hydrogel combining high mechanical robustness and superior water absorption.Extensive experiments demonstrate the effectiveness of RO-TWSA across various interactive scenarios,including teleoperation,tactile diagnostics,and robotic autonomous exploration.Overall,RO-TWSA presents a versatile and high-resolution tactile interface,offering new avenues for intelligent perception and interaction in complex real-world environments.
基金supported by the National Key R&D Program of China(2018YFB1501500)the 2115 Talent Development Program of China Agricultural University+3 种基金the National Natural Science Foundation of China(21903001)the Natural Science Foundation of Anhui Province(1908085QB58)the Chinese Universities Scientific Fund(2020TC116)the Research Innovation Fund for Graduate Students of CAU(2020XYZC05A)。
文摘Catalytic hydrodeoxygenation(HDO)of biomass-derived oxy-compounds to advanced hydrocarbon fuels usually requires bifunctional catalysts containing metals and acidic sites.The appropriate tuning of metal and/or acidic active sites at interfaces of bifunctional catalysts can significantly improve catalyst activity and product selectivity.Here,4-trifuoromethyl salicylic acid(TFMSA),as a hydrothermal stable organic acid,was employed to tailor the bifunctional interface of Ru/γ-Al_(2)O_(3)to enhance the catalytic performance on converting lignin-derived phenols to jet fuel range cycloalkanes.More than 80%phenol was converted into cyclohexane at 230°C for 1 h over Ru/γ-Al_(2)O_(3)modified by TFMSA,which was about three times higher than that over unmodified Ru/γ-Al_(2)O_(3).X-ray diffraction(XRD),Transmission electron microscope(TEM),H2 chemisorption,and energy dispersive X-ray spectroscopy(EDS)elemental mapping results indicated that Ru nanoparticles and TFMSA were well distributed onγ-Al_(2)O_(3),and a nanoscale intimacy between Ru and TFMSA was reached.Meanwhile,Fourier transform infrared spectroscopy after pyridine adsorption(Py-FT-IR)analysis proved that Brønsted acidic sites on the catalytic interfaces of TFMSA modified Ru/γ-Al_(2)O_(3)had been improved.Moreover,the kinetic and density functional theory(DFT)results suggested that the synergistic effects of adjacent Ru nanoparticles and acidic sites were crutial for promoting the rate-limiting conversion step of phenol HDO to cyclohexane.
基金supported by the National Key R&D Program of China(2023YFD1701504)the 2115 Talent Development Program of China Agricultural University Fund(1011-00109018)the Beijing Innovation Team of the Modern Agricultural Research System(BAIC08-2023-FQ02)。
文摘Optimizing the intrinsic activity of non-noble metal by precisely tailoring electronic structure offers an appealing way to construct cost-effective catalysts for selective biomass valorization.Herein,we reported a P-doping bifunctional catalyst(Ni-P/mSiO_(2))that achieved 96.6%yield for the hydrogenation rearrangement of furfural to cyclopentanone at mild conditions(1 MPaH_(2),150°C).The turnover frequency of Ni-P/mSiO_(2)was 411.9 h^(-1),which was 3.2-fold than that of Ni/mSiO_(2)(127.2 h^(-1)).Detailed characterizations and differential charge density calculations revealed that the electron-deficient Niδ+species were generated by the electron transfer from Ni to P,which promoted the ring rearrangement reaction.Density functional theory calculations illustrated that the presence of P atoms endowed furfural tilted adsorb on the Ni surface by the C=O group and facilitated the desorption of cyclopentanone.This work unraveled the connection between the localized electronic structures and the catalytic properties,so as to provide a promising reference for designing advanced catalysts for biomass valorization.
文摘In this paper,we consider the difference properties of Riordan arrays.As their applications,we provide some difference identities involving several classical combinatorial sequences such as the generalized Stirling numbers,including Stirling numbers of the first and second kinds and Stirling numbers of type B of the first and second kinds,and Gegenbauer-Humbert-type polynomials.
基金supported by the National Natural Science Foundation of China(Grant Nos.21929401,,22174031,22111540252,21773050)the Fundamental Research Funds forthe Central Universities(HIT.OCEF.2021026)+1 种基金the Heilongjiang Touyan Team(HITTY-20190034)the Natural Science Foundation of Heilongjiang Province(ZD2022B001).
文摘The bottom-up construction of self-powered artificial cells is significant to understand the energy supply and metabolism of nature cells.Here,we demonstrate an efficient manner to build thylakoid-containing artificial cells,which continuously convert light energy into chemical energy to supply adenosine 5'-triphosphate(ATP)under light illumination.The production of ATP supplies energy to promote the biological enzyme cascade reactions,where glucose is transformed into glucose 6-phosphate(G6P)under the catalysis of hexokinase(HK).G6P was further converted to gluconolactone 6-phosphate(PG)in the presence of 6-phosphate dehydrogenase(G6PDH),meanwhile NADP^(+) was converted to nicotinamide adenine dinucleotide phosphate(NADPH).The self-powered artificial cells were demonstrated to generate ATP and NADPH successively,which provided a way for building more complicated artificial cells.
