The reliability of microsystems is an important issue and for their quality inspection, it is necessary to know the displacements or deformations due to the applied mechanical, thermal, or electrostatic loads. We show...The reliability of microsystems is an important issue and for their quality inspection, it is necessary to know the displacements or deformations due to the applied mechanical, thermal, or electrostatic loads. We show how interferometrical techniques like digital holography and speckle interferometry can be used for the measurement of in plane deformations of microsystems with nanometric accuracy and we give a description of the measurement uncertainties.展开更多
Magnetic field-driven spin polarization modulation has emerged as an effective way to boost the electrocatalytic oxygen evolution reaction(OER).However,the correlation among catalyst structure,magnetic property,and ma...Magnetic field-driven spin polarization modulation has emerged as an effective way to boost the electrocatalytic oxygen evolution reaction(OER).However,the correlation among catalyst structure,magnetic property,and magnetic field enhanced-electrochemical activity remains to be fully elucidated.Herein,single-domain CoFe_(2)O_(4) catalysts with tunable oxygen vacancies(CFO-V_(O)) were synthesized to probe how V_(O) mediates magnetism and OER activity under magnetic field.The introduction of V_(O) can simultaneously modulate saturation magnetization(M_(s)) and coercivity(H_(c)),where the increased M_(s) dominates the magnetic field-enhanced OER activity.Under a 14,000 G magnetic field,the optimized CFO-V_(O) exhibits up to 16.1 % reduction in overpotential and 365 % enhancement in magnetocurrent(MC).Electrochemical analyses and post-OER characterization reveal that the magnetic field synergistically improves OER kinetics through lattice distortion induction,magnetohydrodynamic effect,and spin charge transfer effect.Importantly,the magnetic field promotes additional Co^(3+) generation to compensate for charge imbalance caused by V_(O) filling,maintaining dynamic equilibrium of V_(O) and effective reactant adsorption-conversion processes.This work unveils the synergistic mechanism of V_(O) and magnetic parameters for enhancing OER performance under the magnetic field,providing new insights into the design of high-efficiency spinregulated OER catalysts.展开更多
The implementation of multiple pathogen testing is essential for a rapid response to future outbreaks and for reducing disease transmission.This study introduces a 96-channel microfluidic chip,fabricated through a mol...The implementation of multiple pathogen testing is essential for a rapid response to future outbreaks and for reducing disease transmission.This study introduces a 96-channel microfluidic chip,fabricated through a molding process,which enables the batch detection of pathogens.It explores the rapid lysis and elution processes of pathogens within the microfluidic chips to ensure that nucleic acid extraction,elution,and amplification are completed entirely within the chip.This chip can extract nucleic acids from samples in just 10 min,achieving an extraction efficiency comparable to that of traditional in-tube methods.An oil phase is pre-loaded into the chip to effectively prevent aerosol contamination.This approach allows for the simultaneous detection of 21 common respiratory pathogens,with a detection limit of 10 copies per reaction.Furthermore,applications involving clinical samples demonstrate significant practicality.Compared to many traditional in-tube pathogen detection methods and molecular biology technologies that utilize microfluidic chips,this detection chip not only enables simultaneous detection of multiple pathogens but also demonstrates high sensitivity.展开更多
The intrinsic insulation and drastic volume change of the red phosphorus during the 3-electron alloying process greatly limits its widespread applications in sodium-ion batteries.Here,we report a monomicelle-directed ...The intrinsic insulation and drastic volume change of the red phosphorus during the 3-electron alloying process greatly limits its widespread applications in sodium-ion batteries.Here,we report a monomicelle-directed assembly approach for controllable synthesis of monodispersed mesoporous polypyrrole(PPy)nanospheres,which allows for the shape-preserving conversion into N-doped carbon with regular mesoscopic pore and high surface area,thus affording a high dispersion of red phosphorus during melt impregnation process due to the available diffusion apertures and strong molecular chemical anchoring.Moreover,the theoretical calculations further revealed that positively polarized pyridine N atoms in N-doped mesoporous carbon nanospheres can empower comprehensive regulation of red phosphorus adsorption by strong chemical binding.Benefitting from the above advantages,the resultant red phosphorus host for sodium-ion batteries delivered an outstanding reversible capacity of 856 mAh/g with a capacity fading rate of only 0.025%per cycle during 1000 cycles at 1.0 A/g.This work provides an effective approach based on monomicelle-directed assembly engineering of carbon-based phosphorus hosts for advanced energy conversion and storage systems.展开更多
Conventional superconducting nanowire single-photon detectors(SNSPDs)have been typically limited in their applications due to their size,weight,and power consumption,which confine their use to laboratory settings.Howe...Conventional superconducting nanowire single-photon detectors(SNSPDs)have been typically limited in their applications due to their size,weight,and power consumption,which confine their use to laboratory settings.However,with the rapid development of remote imaging,sensing technologies,and long-range quantum communication with fewer topographical constraints,the demand for high-efficiency single-photon detectors integrated with avionic platforms is rapidly growing.We herein designed and manufactured the first drone-based SNSPD system with a system detection efficiency(SDE)as high as 91.8%.This drone-based system incorporates high-performance NbTiN SNSPDs,a self-developed miniature liquid helium dewar,and custom-built integrated electrical setups,making it capable of being launched in complex topographical conditions.Such a drone-based SNSPD system may open the use of SNSPDs for applications that demand high SDE in complex environments.展开更多
Sodium-ion batteries(SIBs)have emerged as a promising contender for next-gener-ation energy storage systems.Hard carbon is re-garded as the most promising anode for commer-cial SIB,however,the large number of defects ...Sodium-ion batteries(SIBs)have emerged as a promising contender for next-gener-ation energy storage systems.Hard carbon is re-garded as the most promising anode for commer-cial SIB,however,the large number of defects on its surface cause irreversible electrolyte consump-tion and an uneven solid electrolyte interphase film.An advanced molecular engineering strategy to coat hard carbon with polycyclic aromatic mo-lecules is reported.Specifically,polystyrene-based carbon microspheres(CSs)were first synthesized and then coated with polycyclic aromatic mo-lecules derived from coal tar pitch by spray-drying and followed by oxidation.Compared to the traditional CVD coating meth-od,this molecular framework strategy has been shown to reduce the number of defects on the surface of CSs without sacrifi-cing internal storage sites and suppressing transport kinetics in hosting the sodium ions.Besides the lower surface defect con-centration,the synthesized hybrid carbon microspheres(HCSs)have a larger grain size and more abundant closed pores,and have a higher reversible sodium storage capacity.A HCS-P-60%electrode has a capacity of 332.3 mAh g^(-1)with an initial Cou-lombic efficiency of 88.5%.It also has a superior rate performance of 246.6 mAh g^(-1)at 2 C and a 95.2%capacity retention after 100 cycles at 0.2 C.This work offers new insights into designing high-performance hard carbon microsphere anodes,advan-cing the commercialization of sodium-ion batteries.展开更多
Three-dimensional(3D)nanoprinting via two-photon polymerization offers unparalleled design flexibility and precision,thereby enabling rapid prototyping of advanced micro-optical elements and systems that have found im...Three-dimensional(3D)nanoprinting via two-photon polymerization offers unparalleled design flexibility and precision,thereby enabling rapid prototyping of advanced micro-optical elements and systems that have found important applications in endomicroscopy and biomedical imaging.The potential of this versatile tool for monolithic manufacturing of dynamic micro-opto-electro-mechanical systems(MOEMSs),however,has not yet been sufficiently explored.This work introduces a 3D-nanoprinted lens actuator with a large optical aperture,optimized for remote focusing in miniaturized imaging systems.The device integrates orthoplanar linear motion springs,a self-aligned sintered micro-magnet,and a monolithic lens,actuated by dual microcoils for uniaxial motion.The use of 3D nanoprinting allows complete design freedom for the integrated optical lens,whereas the monolithic fabrication ensures inherent alignment of the lens with the mechanical elements.With a lens diameter of 1.4 mm and a compact footprint of 5.74 mm,it achieves high mechanical robustness at resonant frequencies exceeding 300 Hz while still providing a large displacement range of 200μm(±100μm).A comprehensive analysis of optical and mechanical performance,including the effects of coil temperature and polymer viscoelasticity,demonstrates its advantages over conventional micro-electro-mechanical system actuators,showcasing its potential for next-generation imaging applications.展开更多
A programmable silicon photonic multiband microwave filter with tunable bandwidths has been demonstrated.The filter has been successfully used to set up a radio-over-fiber link operating in the X-band as a proof of co...A programmable silicon photonic multiband microwave filter with tunable bandwidths has been demonstrated.The filter has been successfully used to set up a radio-over-fiber link operating in the X-band as a proof of concept.For this purpose,we have investigated the programmable photonic integrated circuit comprising 14 tunable balanced Mach–Zehnder interferometers designed into a square mesh architecture and fabricated using CMOS-compatible silicon photonic technology.展开更多
The integration of machine learning and electrocatalysis presents nota ble advancements in designing and predicting the performance of chiral materials for hydrogen evolution reactions(HER).This study utilizes theoret...The integration of machine learning and electrocatalysis presents nota ble advancements in designing and predicting the performance of chiral materials for hydrogen evolution reactions(HER).This study utilizes theoretical calculations and machine learning techniques to assess the HER performance of both chiral and achiral M-N-SWCNTs(M=In,Bi,and Sb)single-atom catalysts(SACs).The stability preferences of metal atoms are dependent on chirality when interacting with chiral SWCNTs.The HER activity of the right-handed In-N-SWCNT is 5.71 times greater than its achiral counterpart,whereas the left-handed In-N-SWCNT exhibits a 5.12-fold enhancement.The calculated hydrogen adsorption free energy for the right-handed In-N-SWCNT reaches as low as-0.02 eV.This enhancement is attributed to the symmetry breaking in spin density distribution,transitioning from C_(2V)in achiral SACs to C_(2)in chiral SACs,which facilitates active site transfer and enhances local spin density.Right-handed M-N-SWCNTs exhibit superiorα-electron separation and transport efficiency relative to left-handed variants,owing to the chiral induced spin selectivity(CISS)effect,with spin-upα-electron density reaching 3.43×10^(-3)e/Bohr^(3)at active sites.Machine learning provides deeper insights,revealing that the interplay of weak spatial electronic effects and appropriate curvature-chirality effects significantly enhances HER performance.A weaker spatial electronic effect correlates with higher HER activity,larger exchange current density,and higher turnover frequency.The curvature-chirality effect undersco res the influence of intrinsic structures on HER performance.These findings offer critical insights into the role of chirality in electrocatalysis and propose innovative approaches for optimizing HER through chirality.展开更多
Micro aerial vehicles(MAVs)have flexibility and maneuverability,which can offer vast potential for applications in both civilian and military domains.Compared to Fixed-wing/Rotor-wing MAVs,Flapping Wing Micro Robots(F...Micro aerial vehicles(MAVs)have flexibility and maneuverability,which can offer vast potential for applications in both civilian and military domains.Compared to Fixed-wing/Rotor-wing MAVs,Flapping Wing Micro Robots(FWMRs)have garnered widespread attention among scientists due to their superior miniaturized aerodynamic theory,reduced noise,and enhanced resistance to disturbances in complex and diverse environments.Flying insects,it not only has remarkable flapping flight ability(wings),but also takeoff and landing habitat ability(legs).If the various functions of flying insects can be imitated,efficient biomimetic FWMRs can be produced.This paper provides a review of the flight kinematics,aerodynamics,and wing structural parameters of insects.Then,the traditional wings and folding wings of insect-inspired FWMRs were compared.The research progress in takeoff and landing of FWMRs was also summarized,and the future developments and challenges for insect-inspired FWMRs were discussed.展开更多
In order to restrain the huge volume expansion of bismuth(Bi)anodes in sodium ion batteries(SIBs),the core-shell structure Bi@mesoporous carbon nanospheres(Bi@mC)composite was designed and prepared by sol-gel method c...In order to restrain the huge volume expansion of bismuth(Bi)anodes in sodium ion batteries(SIBs),the core-shell structure Bi@mesoporous carbon nanospheres(Bi@mC)composite was designed and prepared by sol-gel method coupled heat treatment.Structural characterization displays that the average diameter of the as-prepared Bi@mC composites is about 200 nm and thickness of the N-doped mesoporous carbon shells is 20-30 nm.Electrochemical test and kinetic analysis results show that the mesoporous carbon shell can not only effectively relieve the stress caused by volume expansion of Bi and protect active material from pulverization caused by the stress during charging/discharging process,but also facilitate quick diffusion of sodium ions,thus improving rate and cycling performance.Bi@mC delivers a high specific capacity of 279 mA·h/g and a capacity retention of 97.6%after 3500 cycles at a current density of 5 A/g.Even at a high current density of 20 A/g,Bi@mC can still maintain a high specific capacity of 266 mA·h/g.Additionally,the Bi@mC//NVP full button sodium-ion batteries(SIBs)assembled using Bi@mC anode and Na_(3)V_(2)(PO_(4))_(3)(NVP)cathode deliver an energy density of 182 W·h/kg.展开更多
Single-wavelength interferometry achieves high resolution for smooth surfaces but struggles with rough industrially relevant ones due to limited unambiguous measuring range and speckle effects.Multiwavelength interfer...Single-wavelength interferometry achieves high resolution for smooth surfaces but struggles with rough industrially relevant ones due to limited unambiguous measuring range and speckle effects.Multiwavelength interferometry addresses these challenges using synthetic wavelengths,enabling a balance between extended measurement range and resolution by combining several synthetic wavelengths.This approach holds immense potential for diverse industrial applications,yet it remains largely untapped due to the lack of suitable light sources.Existing solutions are constrained by limited flexibility in synthetic-wavelength generation and slow switching speeds.We demonstrate a light source for multiwavelength interferometry based on electro-optic single-sideband modulation.It reliably generates synthetic wavelengths with arbitrary values from centimeters to meters and switching time below 30 ms.This breakthrough paves the way for dynamic reconfigurable multiwavelength interferometry capable of adapting to complex surfaces and operating efficiently even outside laboratory settings.These capabilities unlock the full potential of multiwavelength interferometry,offering unprecedented flexibility and speed for industrial and technological applications.展开更多
The uplink massive multiple-input multiple-output(MIMO)status update system is very concerned about information freshness performance,especially for some central control Internet of Things(IoT)applications.In this con...The uplink massive multiple-input multiple-output(MIMO)status update system is very concerned about information freshness performance,especially for some central control Internet of Things(IoT)applications.In this context,age of information(AoI),as the metric of information freshness,gets more and more recognition,and simultaneously,the status packet blocklength plays an important role in improving the information freshness.In this work,we firstly consider a case with perfect channel state information(CSI)at the base station(BS),and derive the closed-form expression of the average AoI by using the Shannon theory.Guided by this,we obtain the tradeoff relationship among the status packet blocklength,transmission time and transmission failure probability.Accordingly,we optimize the status packet blocklength to minimize the average AoI.Then,we consider a more practical case with finite blocklength and imperfect CSI at the BS.In this case,we exploit pilot sequence to assist channel estimation,and derive an approximated closed-form expression of the average AoI according to short packet communication theory.It is found that increasing pilot block-length can improve the accuracy of channel estimation but reduce the frequency of status updates.Hence,we jointly optimize the pilot blocklength and status packet blocklength to improve the AoI performance.Extensive simulation results validate that the proposed methods can achieve almost the same performance as the exhaustive search methods.展开更多
Multifocal metalenses are of great concern in optical communications,optical imaging and micro-optics systems,but their design is extremely challenging.In recent years,deep learning methods have provided novel solutio...Multifocal metalenses are of great concern in optical communications,optical imaging and micro-optics systems,but their design is extremely challenging.In recent years,deep learning methods have provided novel solutions to the design of optical planar devices.Here,an approach is proposed to explore the use of generative adversarial networks(GANs)to realize the design of metalenses with different focusing positions at dual wavelengths.This approach includes a forward network and an inverse network,where the former predicts the optical response of meta-atoms and the latter generates structures that meet specific requirements.Compared to the traditional search method,the inverse network demonstrates higher precision and efficiency in designing a dual-wavelength bifocal metalens.The results will provide insights and methodologies for the design of tunable wavelength metalenses,while also highlighting the potential of deep learning in optical device design.展开更多
Optical three-dimensional(3D)measurement is a critical tool in micro-nano manufacturing,the automotive industry,and medical technology due to its nondestructive nature,high precision,and sensitivity.However,passive li...Optical three-dimensional(3D)measurement is a critical tool in micro-nano manufacturing,the automotive industry,and medical technology due to its nondestructive nature,high precision,and sensitivity.However,passive light field system still requires a refractive primary lens to collect light of the scene,and structured light can not work well with the highly refractive object.Meta-optics,known for being lightweight,compact,and easily integrable,has enabled advancements in passive metalens-array light fields and active structured light techniques.Here,we propose and experimentally validate a novel 3D measurement metasystem.It features a transmitting metasurface generating chromatic line focuses as depth markers and a symmetrically arranged receiving metasurface collecting depth-dependent spectral responses.A lightweight,physically interpretable algorithm processes these data to yield high-precision depth information efficiently.Experiments on metallic and wafer materials demonstrate a depth accuracy of±20μm and lateral accuracy of±10μm.This single-layer optical metasystem,characterized by simplicity,micro-level accuracy,easy installation and scalability,shows potential for diverse applications,including process control,surface morphology analysis,and production measurement.展开更多
The integration of artificial intelligence(AI)with satellite technology is ushering in a new era of space exploration,with small satellites playing a pivotal role in advancing this field.However,the deployment of mach...The integration of artificial intelligence(AI)with satellite technology is ushering in a new era of space exploration,with small satellites playing a pivotal role in advancing this field.However,the deployment of machine learning(ML)models in space faces distinct challenges,such as single event upsets(SEUs),which are triggered by space radiation and can corrupt the outputs of neural networks.To defend against this threat,we investigate laser-based fault injection techniques on 55-nm SRAM cells,aiming to explore the impact of SEUs on neural network performance.In this paper,we propose a novel solution in the form of Bin-DNCNN,a binary neural network(BNN)-based model that significantly enhances robustness to radiation-induced faults.We conduct experiments to evaluate the denoising effectiveness of different neural network architectures,comparing their resilience to weight errors before and after fault injections.Our experimental results demonstrate that binary neural networks(BNNs)exhibit superior robustness to weight errors compared to traditional deep neural networks(DNNs),making them a promising candidate for spaceborne AI applications.展开更多
The extensive applications of cubic silicon in flexible transistors and infrared detectors are greatly hindered by its intrinsic properties.Metastable silicon phases,such as Si-Ⅲ,Ⅳ,andⅫ,prepared using extreme press...The extensive applications of cubic silicon in flexible transistors and infrared detectors are greatly hindered by its intrinsic properties.Metastable silicon phases,such as Si-Ⅲ,Ⅳ,andⅫ,prepared using extreme pressure methods,provide a unique“genetic bank”with diverse structures and exotic characteristics.However,exploration of their inherent physical properties remains underdeveloped.Herein,we demonstrate the phase engineering strategy to modulate the thermal conductivity and mechanical properties of metastable silicon.The thermal conductivity,obtained via the Raman optothermal approach,exhibits broad tunability across various Si-Ⅰ,Ⅲ,Ⅻ,andⅣphases.The hardness and Young's modulus of Si-Ⅳare significantly greater than those of the Si-Ⅲ/Ⅻmixture,as confirmed by the nanoindentation technique.Moreover,it was found that pressure-induced structural defects can substantially degrade the thermal and mechanical properties of silicon.This systematic investigation offers a feasible route for designing novel semiconductors and further advancing their desirable applications in advanced nanodevices and mechanical transducers.展开更多
The built-in electric field(BIEF)aroused by the variation in charge distribution between the surface and bulk phase of carbon nitride can improve carrier dynamics.Herein,phosphorus(P)and benzene ringdoped C_(3)N_(5)na...The built-in electric field(BIEF)aroused by the variation in charge distribution between the surface and bulk phase of carbon nitride can improve carrier dynamics.Herein,phosphorus(P)and benzene ringdoped C_(3)N_(5)nanosheets(PPCN_(2))were synthesized by a facile method and demonstrated excellent performance in the photocatalytic degradation of antibiotics.Benzene ring replaced the triazine part of the heptazine unit,expanding the π-conjugated structure of the system,promoting electron delocalization,and enhancing the light-absorbing property.P doping led to the creation of an additional donor state within the P 2p band,facilitating the charge separation and lengthening the transport distance of electron-hole pairs.Additionally,the intermediate state gap created in the Urbach tail further strengthened photon absorption and improved effective electron capture.XPS with Ar ion etching at different depths verified the significant potential difference and large dipole moment caused by different doping levels of surface and bulk phase,resulting in a strong BIEF inside the PPCN_(2).KPFM,SPV,and DFT calculations confirmed the strong BIEF in PPCN_(2).EPR,rotating disk electrode(RRDE)and in situ infrared drift(DRIFT)spectroscopy confirmed the reactive oxygen species and the two-step one-electron reduction reaction mechanism during the photodegradation process.This work provides a new perspective for the study of improving the photocatalytic performance of C_(3)N_(5)by inducing the BIEF which arose from the differences in electronic structure and charge distribution on the surface and bulk phase caused by molecular doping.展开更多
Polyvinyl alcohol(PVA)-based hydrogels are widely used in the fields of tissue engineering,biomedicine,and flexible sensors due to their low cost,excellent biocompatibility,and simple gelation methods.Re-peated freeze...Polyvinyl alcohol(PVA)-based hydrogels are widely used in the fields of tissue engineering,biomedicine,and flexible sensors due to their low cost,excellent biocompatibility,and simple gelation methods.Re-peated freeze-thaw cycles are essential for the preparation of such hydrogels.Although this process can enhance the mechanical properties of the hydrogels to a certain extent,it can also result in opacity and limited tensile performance,significantly restricting their application in wearable devices and electronic skin.This study introduced cellulose nanofibers into polyacrylamide(PAM)/PVA double interpenetrat-ing network hydrogel system,achieving the preparation of a multifunctional composite hydrogel with a“triple-network interlock”structure.Under the synergistic effects of multiple networks,multiple hy-drogen bonds,and nano-reinforcement,this composite hydrogel requires only a single freeze-thaw cycle to achieve a tensile strength exceeding 1 MPa,which is significantly higher than that of PVA hydro-gels subjected to multiple freeze-thaw cycles.The PVA-based hydrogel prepared in this work balances tensile strength(1.41 MPa),elongation(1332%),transparency(89.8%),and toughness(6.73 MJ m^(-3)).Ad-ditionally,this composite hydrogel exhibits high sensitivity(GF=8.74),rapid response(108 ms),fatigue resistance,and antibacterial properties,making it a reliable strain sensor over a wide strain range.When encapsulated on human joints,it can monitor body movements in real-time,such as movements of fin-gers,wrists,elbows,and knees,and can be integrated into peripheral circuits to achieve precise real-time control of robotic hands.This work presents a multifunctional composite hydrogel with great potential as a candidate material for tissue engineering,human-machine interaction,and high-performance wearable sensors.展开更多
基金supported by the German Research Foundation (DFG) under grants OS111/22 and PA792/4
文摘The reliability of microsystems is an important issue and for their quality inspection, it is necessary to know the displacements or deformations due to the applied mechanical, thermal, or electrostatic loads. We show how interferometrical techniques like digital holography and speckle interferometry can be used for the measurement of in plane deformations of microsystems with nanometric accuracy and we give a description of the measurement uncertainties.
基金supported by the “Climbing Plan” of Harbin Normal University (No.XKB202301)National Natural Science Foundation of China (Nos.21871065 and 22071038)。
文摘Magnetic field-driven spin polarization modulation has emerged as an effective way to boost the electrocatalytic oxygen evolution reaction(OER).However,the correlation among catalyst structure,magnetic property,and magnetic field enhanced-electrochemical activity remains to be fully elucidated.Herein,single-domain CoFe_(2)O_(4) catalysts with tunable oxygen vacancies(CFO-V_(O)) were synthesized to probe how V_(O) mediates magnetism and OER activity under magnetic field.The introduction of V_(O) can simultaneously modulate saturation magnetization(M_(s)) and coercivity(H_(c)),where the increased M_(s) dominates the magnetic field-enhanced OER activity.Under a 14,000 G magnetic field,the optimized CFO-V_(O) exhibits up to 16.1 % reduction in overpotential and 365 % enhancement in magnetocurrent(MC).Electrochemical analyses and post-OER characterization reveal that the magnetic field synergistically improves OER kinetics through lattice distortion induction,magnetohydrodynamic effect,and spin charge transfer effect.Importantly,the magnetic field promotes additional Co^(3+) generation to compensate for charge imbalance caused by V_(O) filling,maintaining dynamic equilibrium of V_(O) and effective reactant adsorption-conversion processes.This work unveils the synergistic mechanism of V_(O) and magnetic parameters for enhancing OER performance under the magnetic field,providing new insights into the design of high-efficiency spinregulated OER catalysts.
基金supported by grants from the National Key Research and Development Program of China(Nos.2023YFA0915200,2023YFA0915204)the Equipment Research and Development Projects of the Chinese Academy of Sciences(No.PTYQ2024YZ0010)+3 种基金the Science and Technology Commission of Shanghai Municipality Project(No.XTCX-KJ-2024-038)the Natural Science Foundation of Hebei Province of China(No.H2024206249)the Postdoctoral Fellowship Program of CPSF(No.GZC20232838)Science and Technology Commission of Shanghai Municipality(No.22S31901700).
文摘The implementation of multiple pathogen testing is essential for a rapid response to future outbreaks and for reducing disease transmission.This study introduces a 96-channel microfluidic chip,fabricated through a molding process,which enables the batch detection of pathogens.It explores the rapid lysis and elution processes of pathogens within the microfluidic chips to ensure that nucleic acid extraction,elution,and amplification are completed entirely within the chip.This chip can extract nucleic acids from samples in just 10 min,achieving an extraction efficiency comparable to that of traditional in-tube methods.An oil phase is pre-loaded into the chip to effectively prevent aerosol contamination.This approach allows for the simultaneous detection of 21 common respiratory pathogens,with a detection limit of 10 copies per reaction.Furthermore,applications involving clinical samples demonstrate significant practicality.Compared to many traditional in-tube pathogen detection methods and molecular biology technologies that utilize microfluidic chips,this detection chip not only enables simultaneous detection of multiple pathogens but also demonstrates high sensitivity.
基金supported by the National Natural Science Foundation of China(Nos.52373208 and 61831021)the Shanghai Undergraduate Training Program on Innovation and Entrepreneurship(No.202310269131S).
文摘The intrinsic insulation and drastic volume change of the red phosphorus during the 3-electron alloying process greatly limits its widespread applications in sodium-ion batteries.Here,we report a monomicelle-directed assembly approach for controllable synthesis of monodispersed mesoporous polypyrrole(PPy)nanospheres,which allows for the shape-preserving conversion into N-doped carbon with regular mesoscopic pore and high surface area,thus affording a high dispersion of red phosphorus during melt impregnation process due to the available diffusion apertures and strong molecular chemical anchoring.Moreover,the theoretical calculations further revealed that positively polarized pyridine N atoms in N-doped mesoporous carbon nanospheres can empower comprehensive regulation of red phosphorus adsorption by strong chemical binding.Benefitting from the above advantages,the resultant red phosphorus host for sodium-ion batteries delivered an outstanding reversible capacity of 856 mAh/g with a capacity fading rate of only 0.025%per cycle during 1000 cycles at 1.0 A/g.This work provides an effective approach based on monomicelle-directed assembly engineering of carbon-based phosphorus hosts for advanced energy conversion and storage systems.
基金the Innovation Program for Quantum Science and Technology(Grant No.2023ZD0300100)the National Key Research and Development Program of China(Grant Nos.2023YFB3809600 and 2023YFC3007801)+1 种基金the National Natural Science Foundation of China(Grant Nos.62301543 and U24A20320)the Shanghai Sailing Program(Grant No.21YF1455700).
文摘Conventional superconducting nanowire single-photon detectors(SNSPDs)have been typically limited in their applications due to their size,weight,and power consumption,which confine their use to laboratory settings.However,with the rapid development of remote imaging,sensing technologies,and long-range quantum communication with fewer topographical constraints,the demand for high-efficiency single-photon detectors integrated with avionic platforms is rapidly growing.We herein designed and manufactured the first drone-based SNSPD system with a system detection efficiency(SDE)as high as 91.8%.This drone-based system incorporates high-performance NbTiN SNSPDs,a self-developed miniature liquid helium dewar,and custom-built integrated electrical setups,making it capable of being launched in complex topographical conditions.Such a drone-based SNSPD system may open the use of SNSPDs for applications that demand high SDE in complex environments.
文摘Sodium-ion batteries(SIBs)have emerged as a promising contender for next-gener-ation energy storage systems.Hard carbon is re-garded as the most promising anode for commer-cial SIB,however,the large number of defects on its surface cause irreversible electrolyte consump-tion and an uneven solid electrolyte interphase film.An advanced molecular engineering strategy to coat hard carbon with polycyclic aromatic mo-lecules is reported.Specifically,polystyrene-based carbon microspheres(CSs)were first synthesized and then coated with polycyclic aromatic mo-lecules derived from coal tar pitch by spray-drying and followed by oxidation.Compared to the traditional CVD coating meth-od,this molecular framework strategy has been shown to reduce the number of defects on the surface of CSs without sacrifi-cing internal storage sites and suppressing transport kinetics in hosting the sodium ions.Besides the lower surface defect con-centration,the synthesized hybrid carbon microspheres(HCSs)have a larger grain size and more abundant closed pores,and have a higher reversible sodium storage capacity.A HCS-P-60%electrode has a capacity of 332.3 mAh g^(-1)with an initial Cou-lombic efficiency of 88.5%.It also has a superior rate performance of 246.6 mAh g^(-1)at 2 C and a 95.2%capacity retention after 100 cycles at 0.2 C.This work offers new insights into designing high-performance hard carbon microsphere anodes,advan-cing the commercialization of sodium-ion batteries.
文摘Three-dimensional(3D)nanoprinting via two-photon polymerization offers unparalleled design flexibility and precision,thereby enabling rapid prototyping of advanced micro-optical elements and systems that have found important applications in endomicroscopy and biomedical imaging.The potential of this versatile tool for monolithic manufacturing of dynamic micro-opto-electro-mechanical systems(MOEMSs),however,has not yet been sufficiently explored.This work introduces a 3D-nanoprinted lens actuator with a large optical aperture,optimized for remote focusing in miniaturized imaging systems.The device integrates orthoplanar linear motion springs,a self-aligned sintered micro-magnet,and a monolithic lens,actuated by dual microcoils for uniaxial motion.The use of 3D nanoprinting allows complete design freedom for the integrated optical lens,whereas the monolithic fabrication ensures inherent alignment of the lens with the mechanical elements.With a lens diameter of 1.4 mm and a compact footprint of 5.74 mm,it achieves high mechanical robustness at resonant frequencies exceeding 300 Hz while still providing a large displacement range of 200μm(±100μm).A comprehensive analysis of optical and mechanical performance,including the effects of coil temperature and polymer viscoelasticity,demonstrates its advantages over conventional micro-electro-mechanical system actuators,showcasing its potential for next-generation imaging applications.
基金Ministry of Electronics and Information Technology(GG-11/15/2020/EMCD)。
文摘A programmable silicon photonic multiband microwave filter with tunable bandwidths has been demonstrated.The filter has been successfully used to set up a radio-over-fiber link operating in the X-band as a proof of concept.For this purpose,we have investigated the programmable photonic integrated circuit comprising 14 tunable balanced Mach–Zehnder interferometers designed into a square mesh architecture and fabricated using CMOS-compatible silicon photonic technology.
基金the full support of the National Natural Science Foundation of China(62071154,51272052 and50902040)the Natural Science Foundation of Heilongjiang Province of China(LH2020B011 and LH2019B006)the Scientific Research Projects of Basic Scientific Research Operational Expenses of Heilongjiang Provincial Colleges and Universities(2021-KYYWF-0171)。
文摘The integration of machine learning and electrocatalysis presents nota ble advancements in designing and predicting the performance of chiral materials for hydrogen evolution reactions(HER).This study utilizes theoretical calculations and machine learning techniques to assess the HER performance of both chiral and achiral M-N-SWCNTs(M=In,Bi,and Sb)single-atom catalysts(SACs).The stability preferences of metal atoms are dependent on chirality when interacting with chiral SWCNTs.The HER activity of the right-handed In-N-SWCNT is 5.71 times greater than its achiral counterpart,whereas the left-handed In-N-SWCNT exhibits a 5.12-fold enhancement.The calculated hydrogen adsorption free energy for the right-handed In-N-SWCNT reaches as low as-0.02 eV.This enhancement is attributed to the symmetry breaking in spin density distribution,transitioning from C_(2V)in achiral SACs to C_(2)in chiral SACs,which facilitates active site transfer and enhances local spin density.Right-handed M-N-SWCNTs exhibit superiorα-electron separation and transport efficiency relative to left-handed variants,owing to the chiral induced spin selectivity(CISS)effect,with spin-upα-electron density reaching 3.43×10^(-3)e/Bohr^(3)at active sites.Machine learning provides deeper insights,revealing that the interplay of weak spatial electronic effects and appropriate curvature-chirality effects significantly enhances HER performance.A weaker spatial electronic effect correlates with higher HER activity,larger exchange current density,and higher turnover frequency.The curvature-chirality effect undersco res the influence of intrinsic structures on HER performance.These findings offer critical insights into the role of chirality in electrocatalysis and propose innovative approaches for optimizing HER through chirality.
基金supported by the National Natural Science Foundation of China(grant numbers 52305321 and 62273246)The Natural Science Foundation of Jiangsu Province(BK20230496)+3 种基金China Postdoctoral Science Foundation Funded Project(2023M732536 and 2024T170630)Jiangsu Province Excellence Postdoctoral Program(2023ZB218)The National Key R&D Program of China(2022YFB4702202)The Jiangsu Provincial Key Technology R&D Program(BE2021009-02).
文摘Micro aerial vehicles(MAVs)have flexibility and maneuverability,which can offer vast potential for applications in both civilian and military domains.Compared to Fixed-wing/Rotor-wing MAVs,Flapping Wing Micro Robots(FWMRs)have garnered widespread attention among scientists due to their superior miniaturized aerodynamic theory,reduced noise,and enhanced resistance to disturbances in complex and diverse environments.Flying insects,it not only has remarkable flapping flight ability(wings),but also takeoff and landing habitat ability(legs).If the various functions of flying insects can be imitated,efficient biomimetic FWMRs can be produced.This paper provides a review of the flight kinematics,aerodynamics,and wing structural parameters of insects.Then,the traditional wings and folding wings of insect-inspired FWMRs were compared.The research progress in takeoff and landing of FWMRs was also summarized,and the future developments and challenges for insect-inspired FWMRs were discussed.
基金the support from National Natural Science Foundation of China (No.52004179)the Fundamental Research Program of Shanxi Province,China (Nos.202403021211028,202303021211036)+1 种基金Shanxi Water and Wood New Carbon Materials Technology Co.,Ltd.,ChinaGuangdong One Nano Technology Co.,Ltd.,China。
文摘In order to restrain the huge volume expansion of bismuth(Bi)anodes in sodium ion batteries(SIBs),the core-shell structure Bi@mesoporous carbon nanospheres(Bi@mC)composite was designed and prepared by sol-gel method coupled heat treatment.Structural characterization displays that the average diameter of the as-prepared Bi@mC composites is about 200 nm and thickness of the N-doped mesoporous carbon shells is 20-30 nm.Electrochemical test and kinetic analysis results show that the mesoporous carbon shell can not only effectively relieve the stress caused by volume expansion of Bi and protect active material from pulverization caused by the stress during charging/discharging process,but also facilitate quick diffusion of sodium ions,thus improving rate and cycling performance.Bi@mC delivers a high specific capacity of 279 mA·h/g and a capacity retention of 97.6%after 3500 cycles at a current density of 5 A/g.Even at a high current density of 20 A/g,Bi@mC can still maintain a high specific capacity of 266 mA·h/g.Additionally,the Bi@mC//NVP full button sodium-ion batteries(SIBs)assembled using Bi@mC anode and Na_(3)V_(2)(PO_(4))_(3)(NVP)cathode deliver an energy density of 182 W·h/kg.
基金supported by the German Federal Ministry of Education and Research,Research Program Quantum Systems(Grant No.13N16774).
文摘Single-wavelength interferometry achieves high resolution for smooth surfaces but struggles with rough industrially relevant ones due to limited unambiguous measuring range and speckle effects.Multiwavelength interferometry addresses these challenges using synthetic wavelengths,enabling a balance between extended measurement range and resolution by combining several synthetic wavelengths.This approach holds immense potential for diverse industrial applications,yet it remains largely untapped due to the lack of suitable light sources.Existing solutions are constrained by limited flexibility in synthetic-wavelength generation and slow switching speeds.We demonstrate a light source for multiwavelength interferometry based on electro-optic single-sideband modulation.It reliably generates synthetic wavelengths with arbitrary values from centimeters to meters and switching time below 30 ms.This breakthrough paves the way for dynamic reconfigurable multiwavelength interferometry capable of adapting to complex surfaces and operating efficiently even outside laboratory settings.These capabilities unlock the full potential of multiwavelength interferometry,offering unprecedented flexibility and speed for industrial and technological applications.
基金supported by National Natural Science Foundation of China (Grants No. 62122094 and No.62171464)
文摘The uplink massive multiple-input multiple-output(MIMO)status update system is very concerned about information freshness performance,especially for some central control Internet of Things(IoT)applications.In this context,age of information(AoI),as the metric of information freshness,gets more and more recognition,and simultaneously,the status packet blocklength plays an important role in improving the information freshness.In this work,we firstly consider a case with perfect channel state information(CSI)at the base station(BS),and derive the closed-form expression of the average AoI by using the Shannon theory.Guided by this,we obtain the tradeoff relationship among the status packet blocklength,transmission time and transmission failure probability.Accordingly,we optimize the status packet blocklength to minimize the average AoI.Then,we consider a more practical case with finite blocklength and imperfect CSI at the BS.In this case,we exploit pilot sequence to assist channel estimation,and derive an approximated closed-form expression of the average AoI according to short packet communication theory.It is found that increasing pilot block-length can improve the accuracy of channel estimation but reduce the frequency of status updates.Hence,we jointly optimize the pilot blocklength and status packet blocklength to improve the AoI performance.Extensive simulation results validate that the proposed methods can achieve almost the same performance as the exhaustive search methods.
基金National Natural Science Foundation of China(No.61975029)。
文摘Multifocal metalenses are of great concern in optical communications,optical imaging and micro-optics systems,but their design is extremely challenging.In recent years,deep learning methods have provided novel solutions to the design of optical planar devices.Here,an approach is proposed to explore the use of generative adversarial networks(GANs)to realize the design of metalenses with different focusing positions at dual wavelengths.This approach includes a forward network and an inverse network,where the former predicts the optical response of meta-atoms and the latter generates structures that meet specific requirements.Compared to the traditional search method,the inverse network demonstrates higher precision and efficiency in designing a dual-wavelength bifocal metalens.The results will provide insights and methodologies for the design of tunable wavelength metalenses,while also highlighting the potential of deep learning in optical device design.
基金financial supports from the National Key R&D Program of China (2021YFA1401200)Beijing Outstanding Young Scientist Program (BJJWZYJH01201910007022)+1 种基金National Natural Science Foundation of China (No. U21A20140, No. 92050117, No. 62105024) programBeijing Natural Science Foundation (JQ24028)
文摘Optical three-dimensional(3D)measurement is a critical tool in micro-nano manufacturing,the automotive industry,and medical technology due to its nondestructive nature,high precision,and sensitivity.However,passive light field system still requires a refractive primary lens to collect light of the scene,and structured light can not work well with the highly refractive object.Meta-optics,known for being lightweight,compact,and easily integrable,has enabled advancements in passive metalens-array light fields and active structured light techniques.Here,we propose and experimentally validate a novel 3D measurement metasystem.It features a transmitting metasurface generating chromatic line focuses as depth markers and a symmetrically arranged receiving metasurface collecting depth-dependent spectral responses.A lightweight,physically interpretable algorithm processes these data to yield high-precision depth information efficiently.Experiments on metallic and wafer materials demonstrate a depth accuracy of±20μm and lateral accuracy of±10μm.This single-layer optical metasystem,characterized by simplicity,micro-level accuracy,easy installation and scalability,shows potential for diverse applications,including process control,surface morphology analysis,and production measurement.
文摘The integration of artificial intelligence(AI)with satellite technology is ushering in a new era of space exploration,with small satellites playing a pivotal role in advancing this field.However,the deployment of machine learning(ML)models in space faces distinct challenges,such as single event upsets(SEUs),which are triggered by space radiation and can corrupt the outputs of neural networks.To defend against this threat,we investigate laser-based fault injection techniques on 55-nm SRAM cells,aiming to explore the impact of SEUs on neural network performance.In this paper,we propose a novel solution in the form of Bin-DNCNN,a binary neural network(BNN)-based model that significantly enhances robustness to radiation-induced faults.We conduct experiments to evaluate the denoising effectiveness of different neural network architectures,comparing their resilience to weight errors before and after fault injections.Our experimental results demonstrate that binary neural networks(BNNs)exhibit superior robustness to weight errors compared to traditional deep neural networks(DNNs),making them a promising candidate for spaceborne AI applications.
基金supported by the National Natural Science Foundation of China(Grant Nos.52472040,52072032,and 12090031)the 173 JCJQ program(Grant No.2021JCJQ-JJ-0159)。
文摘The extensive applications of cubic silicon in flexible transistors and infrared detectors are greatly hindered by its intrinsic properties.Metastable silicon phases,such as Si-Ⅲ,Ⅳ,andⅫ,prepared using extreme pressure methods,provide a unique“genetic bank”with diverse structures and exotic characteristics.However,exploration of their inherent physical properties remains underdeveloped.Herein,we demonstrate the phase engineering strategy to modulate the thermal conductivity and mechanical properties of metastable silicon.The thermal conductivity,obtained via the Raman optothermal approach,exhibits broad tunability across various Si-Ⅰ,Ⅲ,Ⅻ,andⅣphases.The hardness and Young's modulus of Si-Ⅳare significantly greater than those of the Si-Ⅲ/Ⅻmixture,as confirmed by the nanoindentation technique.Moreover,it was found that pressure-induced structural defects can substantially degrade the thermal and mechanical properties of silicon.This systematic investigation offers a feasible route for designing novel semiconductors and further advancing their desirable applications in advanced nanodevices and mechanical transducers.
基金financially supported by the Science and Technology Commission of Shanghai Municipality(No.23HC1400302)the National Natural Science Foundation of China(Nos.22162021 and 21862013)the Natural Science Foundation of Ningxia Province(Nos.2021AAC03057 and 2023AAC03015).
文摘The built-in electric field(BIEF)aroused by the variation in charge distribution between the surface and bulk phase of carbon nitride can improve carrier dynamics.Herein,phosphorus(P)and benzene ringdoped C_(3)N_(5)nanosheets(PPCN_(2))were synthesized by a facile method and demonstrated excellent performance in the photocatalytic degradation of antibiotics.Benzene ring replaced the triazine part of the heptazine unit,expanding the π-conjugated structure of the system,promoting electron delocalization,and enhancing the light-absorbing property.P doping led to the creation of an additional donor state within the P 2p band,facilitating the charge separation and lengthening the transport distance of electron-hole pairs.Additionally,the intermediate state gap created in the Urbach tail further strengthened photon absorption and improved effective electron capture.XPS with Ar ion etching at different depths verified the significant potential difference and large dipole moment caused by different doping levels of surface and bulk phase,resulting in a strong BIEF inside the PPCN_(2).KPFM,SPV,and DFT calculations confirmed the strong BIEF in PPCN_(2).EPR,rotating disk electrode(RRDE)and in situ infrared drift(DRIFT)spectroscopy confirmed the reactive oxygen species and the two-step one-electron reduction reaction mechanism during the photodegradation process.This work provides a new perspective for the study of improving the photocatalytic performance of C_(3)N_(5)by inducing the BIEF which arose from the differences in electronic structure and charge distribution on the surface and bulk phase caused by molecular doping.
基金supported by the National Key Research and Development Program(No.2022YFB3304000)the National Natural Science Foundation of China(No.52275292)+5 种基金the Fundamental Research Funds for the Central Universities(No.D5000240313)the Key Research and Development Program of Shaanxi Province(No.2022GY-228)the Science and technology planning project of Xian(No.20KYPT0002-1)the Fundamental Research Funds for the Central Universities(Nos.D5000230084 and 3102022gxb002)the Shaanxi Province Key Research and Development Projects(Nos.2021LLRH08 and 2022GXLH-02-15)the Emerging Interdisciplinary Project of Northwestern Polytechnical University(No.22GH0306).
文摘Polyvinyl alcohol(PVA)-based hydrogels are widely used in the fields of tissue engineering,biomedicine,and flexible sensors due to their low cost,excellent biocompatibility,and simple gelation methods.Re-peated freeze-thaw cycles are essential for the preparation of such hydrogels.Although this process can enhance the mechanical properties of the hydrogels to a certain extent,it can also result in opacity and limited tensile performance,significantly restricting their application in wearable devices and electronic skin.This study introduced cellulose nanofibers into polyacrylamide(PAM)/PVA double interpenetrat-ing network hydrogel system,achieving the preparation of a multifunctional composite hydrogel with a“triple-network interlock”structure.Under the synergistic effects of multiple networks,multiple hy-drogen bonds,and nano-reinforcement,this composite hydrogel requires only a single freeze-thaw cycle to achieve a tensile strength exceeding 1 MPa,which is significantly higher than that of PVA hydro-gels subjected to multiple freeze-thaw cycles.The PVA-based hydrogel prepared in this work balances tensile strength(1.41 MPa),elongation(1332%),transparency(89.8%),and toughness(6.73 MJ m^(-3)).Ad-ditionally,this composite hydrogel exhibits high sensitivity(GF=8.74),rapid response(108 ms),fatigue resistance,and antibacterial properties,making it a reliable strain sensor over a wide strain range.When encapsulated on human joints,it can monitor body movements in real-time,such as movements of fin-gers,wrists,elbows,and knees,and can be integrated into peripheral circuits to achieve precise real-time control of robotic hands.This work presents a multifunctional composite hydrogel with great potential as a candidate material for tissue engineering,human-machine interaction,and high-performance wearable sensors.
