Self-healable and flexible all-in-one self-powering smartsensing devices have recently attracted great attention.Herein,a flexible all-in-one solid-state electronic system of polyvinyl alcohol(PVA)hydrogel-based super...Self-healable and flexible all-in-one self-powering smartsensing devices have recently attracted great attention.Herein,a flexible all-in-one solid-state electronic system of polyvinyl alcohol(PVA)hydrogel-based supercapacitors for self-powering ammonia smartsensors has been fabricated.Self-healing supercapacitors are prepared by integrating polypyrrole(PPy)and boron crosslinked PVA/KCl hydrogel as a sandwich configuration,exhibiting large specific capacitance of 244.81 mF cm^(-2)at 0.47 mA cm^(-2),and good charging/discharging stability of 2000 cycles,while ammonia sensors are realized by a SnO_(2)/PPy-modified conductive PVA hydrogel film,demonstrating an excellent sensing behavior toward NH_(3) vapor under 50 ppb–500 ppm.As a result,selfhealing supercapacitors could well store energy and then self-power sensing unit for remotely real-time detection via a smartphone,acquiring high flexibility of energy-sensing system.With attractive biocompatibility and selfhealing performance toward various environment,this all-in-one flexible energy-smartsensor system would pave the way to novel fabrication process in realization of wearable self-healing smart devices.展开更多
Poly(L-lactic acid)(PLLA)is a biocompatible,biodegradable material with piezoelectric properties,making it a promising candidate for providing self-powered stimulation to accelerate tissue re-pair.Repairs to various t...Poly(L-lactic acid)(PLLA)is a biocompatible,biodegradable material with piezoelectric properties,making it a promising candidate for providing self-powered stimulation to accelerate tissue re-pair.Repairs to various tissues,such as bone,cartilage and nerve,necessitate distinct piezoelectric characteristics even from the same material.However,the extensive utilization of PLLA piezoelectric scaffolds in various tissue is hindered by their low and single piezoelectric constants.In this study,PLLA nanofiber membranes with enhanced and adjustable piezoelectric constants(d_(33))were fabricated through oriented electrospinning.By carefully controlling the parameters of the spinning solution,a steady increase in d_(33) values from 0 to 30 pC/N was achieved.This advancement allows tailoring of PLLA nanofiber membranes to meet various piezoelectric requirements of different tissues.As an example of tailoring the optimal piezoelectric constants,we developed PLLA-2-0,PLLA-2-10,PLLA-2-15 and PLLA-2-20 nanofiber membranes with d_(33) values of 0,5,10 and 15 pC/N,respectively.The impact of varying piezoelectric constants of PLLA nanofiber membranes on cellular behavior and repair efficacy were validated through in vitro cellular experiments and in vivo mandibular critical defect repair.The results indicated that PLLA-2-20 demonstrated superior cell proliferation rate up to 130%and an osteogenic differentiation level approximately twice of the control.In addition,PLLA-2-20 significantly promoted cell adhesion and migration,and the cell aspect ratio was about five times higher than that of the control group.In vivo,PLLA-2-20 optimal restorative effects on rat mandibles via endogenous mechanical force-mediated piezoelectric stimulation,leading to complete histological restoration within 8 weeks.These findings highlight the potential of the PLLA membranes with high and adjustable d_(33) by a straightforward process.This study provides a novel approach for the development of highly electroactive membranes tailored to specific tissue repair needs.展开更多
Possessing excellent mechanical properties,a high-coverage slide-ring conductive gel is constructed by in situ polymerization ofα-cyclodextrin(α-CD)polyrotaxane(PR)and 1-vinyl-3-ethylimidazolium bromide([VEIM]Br)ion...Possessing excellent mechanical properties,a high-coverage slide-ring conductive gel is constructed by in situ polymerization ofα-cyclodextrin(α-CD)polyrotaxane(PR)and 1-vinyl-3-ethylimidazolium bromide([VEIM]Br)ionic liquid(IL),using 1-ethyl-3-methylimidazolium bromide([EMIM]Br)IL as solvent.Benefiting from the compatibility of ILs and alkene-PR,the cross-linked network slide-ring gel not only maintains excellent conductivity(1.52×10^(−2) S/m),but also has effectively improved mechanical properties(513%fracture strain,0.713 MPa fracture stress,211 kPa elastic modulus and 1366 kJ/m^(3) toughness)and adhesive properties(472.3±25.9 kPa).The supramolecular gel can be used as a strain sensor to efficiently monitor deformation signals in real-time at least 200 times.Especially,the slide-ring gel can self-power generated by triboelectric effect and electrostatic induction between the skin layer and the polydimethylsiloxane(PDMS)layer that encapsulates the gel,achieving reversible and durable motion sensing,which provides a convenient pathway for constructing supramolecular self-powered flexible electronic materials.展开更多
Advanced healthcare monitors for air pollution applications pose a significant challenge in achieving a balance between high-performance filtration and multifunctional smart integration.Electrospinning triboelectric n...Advanced healthcare monitors for air pollution applications pose a significant challenge in achieving a balance between high-performance filtration and multifunctional smart integration.Electrospinning triboelectric nanogenerators(TENG)provide a significant potential for use under such difficult circumstances.We have successfully constructed a high-performance TENG utilizing a novel multi-scale nanofiber architecture.Nylon 66(PA66)and chitosan quaternary ammonium salt(HACC)composites were prepared by electrospinning,and PA66/H multiscale nanofiber membranes composed of nanofibers(≈73 nm)and submicron-fibers(≈123 nm)were formed.PA66/H multi-scale nanofiber membrane as the positive electrode and negative electrode-spun PVDF-HFP nanofiber membrane composed of respiration-driven PVDF-HFP@PA66/H TENG.The resulting PVDF-HFP@PA66/H TENG based air filter utilizes electrostatic adsorption and physical interception mechanisms,achieving PM_(0.3)filtration efficiency over 99%with a pressure drop of only 48 Pa.Besides,PVDF-HFP@PA66/H TENG exhibits excellent stability in high-humidity environments,with filtration efficiency reduced by less than 1%.At the same time,the TENG achieves periodic contact separation through breathing drive to achieve self-power,which can ensure the long-term stability of the filtration efficiency.In addition to the air filtration function,TENG can also monitor health in real time by capturing human breathing signals without external power supply.This integrated system combines high-efficiency air filtration,self-powered operation,and health monitoring,presenting an innovative solution for air purification,smart protective equipment,and portable health monitoring.These findings highlight the potential of this technology for diverse applications,offering a promising direction for advancing multifunctional air filtration systems.展开更多
With the rapid advancement of optoelectronic technology,high-performance photodetectors are increasingly in demand in fields such as environmental monitoring,optical communication,and defense systems,where ultraviolet...With the rapid advancement of optoelectronic technology,high-performance photodetectors are increasingly in demand in fields such as environmental monitoring,optical communication,and defense systems,where ultraviolet detection is critical.However,conventional semiconductor materials suffer from limited UV-visible detection capabilities owing to their narrow bandgaps and high dark currents.To address these challenges,wide-bandgap semiconductors have emerged as promising alternatives.Here,we fabricated a horizontally structured n–n heterojunction photodetector by growingβ-Ga_(2)O_(3) on Si–GaN via plasma-enhanced chemical vapor deposition.The device exhibits a self-powered photocurrent of 3.5 nA at zero bias,enabled by the photovoltaic effect of the space charge region.Under 254-nm and 365-nm illumination,it exhibits rectification behavior,achieving a responsivity of 0.475 m A/W(0 V,220??W/cm~2 at 254 nm)and 257.6 mA/W(-5 V),respectively.Notably,the photodetector demonstrates a high photocurrent-to-dark current ratio of 10~5 under-5-V bias,highlighting its potential for self-powered and high-performance UV detection applications.展开更多
Smart farming with outdoor monitoring systems is critical to address food shortages and sustainability challenges.These systems facilitate informed decisions that enhance efficiency in broader environmental management...Smart farming with outdoor monitoring systems is critical to address food shortages and sustainability challenges.These systems facilitate informed decisions that enhance efficiency in broader environmental management.Existing outdoor systems equipped with energy harvesters and self-powered sensors often struggle with fluctuating energy sources,low durability under harsh conditions,non-transparent or non-biocompatible materials,and complex structures.Herein,a multifunctional hydrogel is developed,which can fulfill all the above requirements and build selfsustainable outdoor monitoring systems solely by it.It can serve as a stable energy harvester that continuously generates direct current output with an average power density of 1.9 W m^(-3)for nearly 60 days of operation in normal environments(24℃,60%RH),with an energy density of around 1.36×10^(7)J m^(-3).It also shows good self-recoverability in severe environments(45℃,30%RH)in nearly 40 days of continuous operation.Moreover,this hydrogel enables noninvasive and self-powered monitoring of leaf relative water content,providing critical data on evaluating plant health,previously obtainable only through invasive or high-power consumption methods.Its potential extends to acting as other self-powered environmental sensors.This multifunctional hydrogel enables self-sustainable outdoor systems with scalable and low-cost production,paving the way for future agriculture.展开更多
Belt conveyors are extensively utilized in mining and power industries.In a typical coal mine conveyor system,coal is transported over distances exceeding 2 km,involving more than 20000 idlers,which far exceeds a reas...Belt conveyors are extensively utilized in mining and power industries.In a typical coal mine conveyor system,coal is transported over distances exceeding 2 km,involving more than 20000 idlers,which far exceeds a reasonable manual inspection capacity.Given that idlers typically have a lifespan of 1-2 years,there is an urgent need for a rapid,cost-effective,and intelligent safety monitoring system.However,current embedded systems face prohibitive replacement costs,while conventional monitoring technologies suffer from inefficiency at low rotational speeds and lack systematic structural optimization frameworks for diverse idler types and parameters.To address these challenges,this paper introduces an integrated,on-site detachable self-powered idler condition monitoring system(ICMS).This system combines energy harvesting based on the magnetic modulation technology with wireless condition monitoring capabilities.Specifically,it develops a data-driven model integrating convolutional neural networks(CNNs) with genetic algorithms(GAs).The conventional testing results show that the data-driven model not only significantly accelerates the parameter response time,but also achieves a prediction accuracy of 92.95%.The in-situ experiments conducted in coal mines demonstrate the system's reliability and monitoring functionality under both no-load and fullload conditions.This research provides an innovative self-powered condition monitoring solution and develops an efficient data-driven model,offering feasible online monitoring approaches for smart mine construction.展开更多
Self-regulating heating and self-powered flexibility are pivotal for future wearable devices.However,the low energy-conversion rate of wearable devices at low temperatures limits their application in plateaus and othe...Self-regulating heating and self-powered flexibility are pivotal for future wearable devices.However,the low energy-conversion rate of wearable devices at low temperatures limits their application in plateaus and other environments.This study introduces an azopolymer with remarkable semicrystallinity and reversible photoinduced solid-liquid transition ability that is obtained through copolymerization of azoben-zene(Azo)monomers and styrene.A composite of one such copolymer with an Azo:styrene molar ratio of 9:1(copolymer is denoted as PAzo9:1-co-polystyrene(PS))and nylon fabrics(NFs)is prepared(composite is denoted as PAzo9:1-co-PS@NF).PAzo9:1-co-PS@NF exhibits hydrophobicity and high wear resistance.Moreover,it shows good responsiveness(0.624 s^(−1))during isomerization under solid ultraviolet(UV)light(365 nm)with an energy density of 70.6 kJ kg^(−1).In addition,the open-circuit voltage,short-circuit current and quantity values of PAzo9:1-co-PS@NF exhibit small variations in a temperature range of−20℃ to 25℃ and remain at 170 V,5 μA,and 62 nC,respectively.Notably,the involved NFs were cut and sewn into gloves to be worn on a human hand model.When the model was exposed to both UV radiation and friction,the temperature of the finger coated with PAzo9:1-co-PS was approximately 6.0°C higher than that of the other parts.Therefore,developing triboelectric nanogenerators based on the in situ photothermal cycles of Azo in wearable devices is important to develop low-temperature self-regulating heating and self-powered flexible devices for extreme environments.展开更多
Today,energy is essential for every aspect of human life,including clothing,food,housing and transportation.However,traditional energy resources are insufficient to meet our modern needs.Self-powered sensing devices e...Today,energy is essential for every aspect of human life,including clothing,food,housing and transportation.However,traditional energy resources are insufficient to meet our modern needs.Self-powered sensing devices emerge as promising alternatives,offering sustained operation without relying on external power sources.Leveraging advancements in materials and manufacturing research,these devices can autonomously harvest energy from various sources.In this review,we focus on the current landscape of self-powered wearable sensors,providing a concise overview of energy harvesting technologies,conversion mechanisms,structural or material innovations,and energy storage platforms.Then,we present experimental advances in different energy sources,showing their underlying mechanisms,and the potential for energy acquisition.Furthermore,we discuss the applications of self-powered flexible sensors in diverse fields such as medicine,sports,and food.Despite significant progress in this field,widespread commercialization will necessitate enhanced sensor detection abilities,improved design factors for adaptable devices,and a balance between sensitivity and standardization.展开更多
Quantum dot(QD)-based infrared photodetector is a promising technology that can implement current monitoring,imaging and optical communication in the infrared region. However, the photodetection performance of self-po...Quantum dot(QD)-based infrared photodetector is a promising technology that can implement current monitoring,imaging and optical communication in the infrared region. However, the photodetection performance of self-powered QD devices is still limited by their unfavorable charge carrier dynamics due to their intrinsically discrete charge carrier transport process. Herein, we strategically constructed semiconducting matrix in QD film to achieve efficient charge transfer and extraction.The p-type semiconducting CuSCN was selected as energy-aligned matrix to match the n-type colloidal PbS QDs that was used as proof-of-concept. Note that the PbS QD/CuSCN matrix not only enables efficient charge carrier separation and transfer at nano-interfaces but also provides continuous charge carrier transport pathways that are different from the hoping process in neat QD film, resulting in improved charge mobility and derived collection efficiency. As a result, the target structure delivers high specific detectivity of 4.38 × 10^(12)Jones and responsivity of 782 mA/W at 808 nm, which is superior than that of the PbS QD-only photodetector(4.66 × 10^(11)Jones and 338 mA/W). This work provides a new structure candidate for efficient colloidal QD based optoelectronic devices.展开更多
β-Ga_(2)O_(3),as one of the important 4th generation semiconductors,is widely used in solar-blind ultraviolet(UV)detectors with a short detection range of 200-280 nm benefiting from its ultra-wide bandgap,strong radi...β-Ga_(2)O_(3),as one of the important 4th generation semiconductors,is widely used in solar-blind ultraviolet(UV)detectors with a short detection range of 200-280 nm benefiting from its ultra-wide bandgap,strong radiation resistance,and excellent chemical and thermal stabilities.Here,a self-powered photodetector(PD)based on an Ag/β-Ga_(2)O_(3) Schottky heterojunction was designed and fabricated.Through a subtle design of electrodes,the pyro-phototronic effect was discovered,which can be coupled to the common photovoltaic effect and further enhance the performance of the PD.Compared to traditional Ga_(2)O_(3)-based PD,the as-used PD exhibited a self-driving property and a broadband response beyond the bandgap lim-itations,ranging from 200 nm(deep UV)to 980 nm(infrared).Moreover,the photoresponse time was greatly shrunk owing to the coupling effect.Under laser irradiation,with a wavelength of 450 nm and a power density of 8 mW cm-2,the photocurrent could be improved by around 41 times compared with the sole photovoltaic effect.Besides,the performances of the Schottky PD were enhanced at both high and low temperatures.The device also possessed long-term working stability.This paper not only re-veals basic physics lying in the 4th generation semiconductor Ga_(2)O_(3) but also sheds light on the multi-encryption transmission of light information using this PD.展开更多
This study explores how the performance of triboelectric nanogenerators can be enhanced by incorporating Fe_(3)O_(4) nanoparticles into nylon films using a spray coating technique.Five triboelectric nanogenerator prot...This study explores how the performance of triboelectric nanogenerators can be enhanced by incorporating Fe_(3)O_(4) nanoparticles into nylon films using a spray coating technique.Five triboelectric nanogenerator prototypes were created:one with regular nylon and four with nylon/Fe_(3)O_(4) nanocomposites featuring varying nanoparticle densities.The electrical output,measured by open-circuit voltage and short-circuit current,showed significant improvements in the nanocomposite-based triboelectric nanogenerators compared to the nylon-only triboelectric nanogenerator.When a weak magnetic field was applied during nanocomposite preparation,the maximum voltage and current reached 56.3 V and 4.62μA,respectively.Further analysis revealed that the magnetic field during the drying process aligned the magnetic domains,boosting output efficiency.These findings demonstrate the potential of Fe_(3)O_(4) nanoparticles to enhance electrostatic and magnetic interactions in triboelectric nanogenerators,leading to improved energy-harvesting performance.This approach presents a promising strategy for developing high-performance triboelectric nanogenerators for sustainable energy and sensor applications.展开更多
Two-dimensional perovskite ferroelectric which strongly couple ferroelectricity with semiconducting properties are promising candidates for optoelectronic applications.However,it is still a great challenge to fabricat...Two-dimensional perovskite ferroelectric which strongly couple ferroelectricity with semiconducting properties are promising candidates for optoelectronic applications.However,it is still a great challenge to fabricate self-powered broadband photodetectors with low detection limit.Herein,we successfully realized self-powered broadband photodetection with low detection limit by using a trilayered perovskite ferroelectric(BA)_(2)EA_(2)Pb_(3)I_(10)(1,BA=n-butylamine,EA=ethylamine).Giving to its large spontaneous polarization(5.6μC/cm^(2)),1 exhibits an open-circuit voltage of 0.25 V which provide driving force to separate carriers.Combining with its low dark current(~10^(-14)A)and narrow bandgap(Eg=1.86 e V),1 demonstrates great potential on detecting the broadband weak lights.Thus,a prominent photodetection performance with high open-off ratio(~10^(5)),outstanding responsivity(>10 m A/W),and promising detectivity(>1011Jones),as well as the low detecting limit(~nW/cm^(2))among the wide wavelength from 377 nm to637 nm was realized based on the single crystal of 1.This work demonstrates the great potential of 2D perovskite ferroelectric on self-powered broadband photodetectors.展开更多
The rise of smart wearable devices has driven the demand for flexible,high-performance optoelectronic devices with low power and easy high-density integration.Emerging Two-dimensional(2D)materials offer promising solu...The rise of smart wearable devices has driven the demand for flexible,high-performance optoelectronic devices with low power and easy high-density integration.Emerging Two-dimensional(2D)materials offer promising solutions.However,the use of 3D metal in traditional 2D devices often leads to Fermi-level pinning,compromising device performance.2D metallic materials,such as graphene and 2H-phase NbSe_(2),present a new avenue for addressing this issue and constructing high-performance,low-power photodetectors.In this work,we designed an all-2D asymmetric contacts photodetector using Gr and NbSe_(2)as electrodes for the 2D semiconductor WSe_(2).The asymmetric Schottky barriers and built-in electric fields facilitated by this architecture resulted in outstanding photovoltaic characteristics and self-powered photodetection.Under zero bias,the device exhibited a responsivity of 287 mA/W,a specific detectivity of 5.3×10^(11)Jones,and an external quantum efficiency of 88%.It also demonstrated an ultra-high light on/offratio(1.8×10^(5)),ultra-fast photoresponse speeds(80/72μs),broad-spectrum responsiveness(405980 nm),and exceptional cycling stability.The applications of the Gr/WSe_(2)/NbSe_(2)heterojunction in imaging and infrared optical communication have been explored,underscoring its significant potential.This work offers an idea to construct all-2D ultrathin optoelectronic devices.展开更多
Recently,self-powered ultraviolet photodetectors(UV PDs)based on SnO_(2)have gained increasing interest due to its feature of working continuously without the need for external power sources.Nevertheless,the productio...Recently,self-powered ultraviolet photodetectors(UV PDs)based on SnO_(2)have gained increasing interest due to its feature of working continuously without the need for external power sources.Nevertheless,the production of the majority of these existing UV PDs necessitates additional manufacturing stages or intricate processes.In this work,we present a facile,cost-effective approach for the fabrication of a self-powered UV PD based on p-Si/n-SnO_(2)junction.The self-powered device was achieved simply by integrating a p-Si substrate with a n-type SnO_(2)microbelt,which was synthesized via the chemical vapor deposition(CVD)method.The high-quality feature,coupled with the belt-like shape of the SnO_(2)microbelt enables the favorable contact between the n-type SnO_(2)and p-type silicon.The built-in electric field created at the interface endows the self-powered performance of the device.The p-Si/n-SnO_(2)junction photodetector demonstrated a high responsivity(0.12 mA/W),high light/dark current ratio(>103),and rapid response speed at zero bias.This method offers a practical way to develop cost-effective and high-performance self-powered UV PDs.展开更多
Due to its ability to convert body heat into electricity,organic thermoelectric material is considered a promising and smart maintenance-free power source to charge wearable electronics.However,developing flexible n-t...Due to its ability to convert body heat into electricity,organic thermoelectric material is considered a promising and smart maintenance-free power source to charge wearable electronics.However,developing flexible n-type organic thermoelectric materials and wearable p/n junction thermoelectric devices remains challenging.In this work,two insulated polyamides(PA6 and PA66)that have been widely used as fiber materials are employed as novel dopants for converting p-type single-walled carbon nanotubes(SWCNTs)to n-type thermoelectric materials.Because of the electron transferability of the amide group,polyamide-doped SWCNTs exhibit excellent thermopower values as large as-56.0μV K^(-1) for PA66,and-54.5μV K^(-1) for PA6.Thermoelectric devices with five p/n junctions connected in series are fabricated.The testing device produces a thermoelectric voltage of 43.1 mV and generates 1.85μW thermoelectric power under temperature gradients of approximately 80 K.Furthermore,they display charming capability for temperature recognition and monitoring human activities as sensors.These promising results suggest that the flexible polyamide-doped SWCNT composites herein have high application potential as wearable thermoelectric electronics.展开更多
Low power consumption,high responsivity,and self-powering are key objectives for photoelectrochemical ultravio-let detectors.In this research,In-dopedα-Ga_(2)O_(3) nanowire arrays were fabricated on fluorine-doped ti...Low power consumption,high responsivity,and self-powering are key objectives for photoelectrochemical ultravio-let detectors.In this research,In-dopedα-Ga_(2)O_(3) nanowire arrays were fabricated on fluorine-doped tin oxide(FTO)substrates through a hydrothermal approach,with subsequent thermal annealing.These arrays were then used as photoanodes to con-struct a ultraviolet(UV)photodetector.In doping reduced the bandgap ofα-Ga_(2)O_(3),enhancing its absorption of UV light.Conse-quently,the In-dopedα-Ga_(2)O_(3) nanowire arrays exhibited excellent light detection performance.When irradiated by 255 nm deep ultraviolet light,they obtained a responsivity of 38.85 mA/W.Moreover,the detector's response and recovery times are 13 and 8 ms,respectively.The In-dopedα-Ga_(2)O_(3) nanowire arrays exhibit a responsivity that is about three-fold higher than the undoped one.Due to its superior responsivity,the In-doped device was used to develop a photoelectric imaging system.This study demonstrates that dopingα-Ga_(2)O_(3) nanowire with indium is a potent approach for optimizing their photoelectrochemi-cal performance,which also has significant potential for optoelectronic applications.展开更多
Polar semiconductors,particularly the emerging polar two-dimensional(2D)halide perovskites,have motivated immense interest in diverse photoelectronic devices due to their distinguishing polarizationgenerated photoelec...Polar semiconductors,particularly the emerging polar two-dimensional(2D)halide perovskites,have motivated immense interest in diverse photoelectronic devices due to their distinguishing polarizationgenerated photoelectric effects.However,the constraints on the organic cation's choice are still subject to limitations of polar 2D halide perovskites due to the size of the inorganic pocket between adjacent corner-sharing octahedra.Herein,a mixed spacer cation ordering strategy is employed to assemble a polar 2D halide perovskite NMAMAPb Br_(4)(NMPB,NMA is N-methylbenzene ammonium,MA is methylammonium)with alternating cation in the interlayer space.Driven by the incorporation of a second MA cation,the perovskite layer transformed from a 2D Pb_(7)Br_(24)anionic network with corner-and face-sharing octahedra to a flat 2D PbBr_(4)perovskite networks only with corner-sharing octahedra.In the crystal structure of NMPB,the asymmetric hydrogen-bonding interactions between ordered mixed-spacer cations and 2D perovskite layers give rise to a second harmonic generation response and a large polarization of 1.3μC/cm^(2).More intriguingly,the ordered 2D perovskite networks endow NMPB with excellent self-powered polarization-sensitive detection performance,showing a considerable polarization-related dichroism ratio up to 1.87.The reconstruction of an inorganic framework within a crystal through mixed cation ordering offers a new synthetic tool for templating perovskite lattices with controlled properties,overcoming limitations of conventional cation choice.展开更多
Self-powered neutron detectors(SPNDs)play a critical role in monitoring the safety margins and overall health of reactors,directly affecting safe operation within the reactor.In this work,a novel fault identification ...Self-powered neutron detectors(SPNDs)play a critical role in monitoring the safety margins and overall health of reactors,directly affecting safe operation within the reactor.In this work,a novel fault identification method based on graph convolutional networks(GCN)and Stacking ensemble learning is proposed for SPNDs.The GCN is employed to extract the spatial neighborhood information of SPNDs at different positions,and residuals are obtained by nonlinear fitting of SPND signals.In order to completely extract the time-varying features from residual sequences,the Stacking fusion model,integrated with various algorithms,is developed and enables the identification of five conditions for SPNDs:normal,drift,bias,precision degradation,and complete failure.The results demonstrate that the integration of diverse base-learners in the GCN-Stacking model exhibits advantages over a single model as well as enhances the stability and reliability in fault identification.Additionally,the GCN-Stacking model maintains higher accuracy in identifying faults at different reactor power levels.展开更多
Targeting spontaneous coal combustion during stacking,we developed an efficient heat dissipation&self-supplied wireless temperature measurement system(SPWTM)with gravity heat pipe-thermoelectric integration for du...Targeting spontaneous coal combustion during stacking,we developed an efficient heat dissipation&self-supplied wireless temperature measurement system(SPWTM)with gravity heat pipe-thermoelectric integration for dual safety.The heat transfer characteristics and temperature measurement optimization of the system are experimentally investigated and verified in practical applications.The results show that,firstly,the effects of coal pile heat production power and burial depth,along with heat pipe startup and heat transfer characteristics.At 60 cmburial depth,the condensation section dissipates 98%coal pile heat via natural convection.Secondly,for the temperature measurement error caused by the heat pipe heat transfer temperature difference,the correction method of“superimposing the measured value with the heat transfer temperature difference”is proposed,and the higher the coal temperature,the better the temperature measurement accuracy.Finally,the system can quickly(≤1 h)reduce the temperature of the coal pile to the spontaneous combustion point,significantly inhibiting the spontaneous combustion phenomenon,the maximum temperature does not exceed 49.2℃.Meanwhile,it utilizes waste heat to drive thermoelectric power generation,realizing self-supplied,unattended,and long-term accurate temperature measurement and warning.In a word,synergistic active heat dissipation and self-powered temperature monitoring-warning ensure dual coal pile thermal safety.展开更多
基金financial support from National Natural Science Foundation of China(Grant No.22074010)Dalian Science and Technology Bureau,China(Grant No.2019J12SN54)+1 种基金Basic and Applied Basic Research Program of Guangzhou City,China(Grant No.202002030434)Zhang Dayu School of Chemistry,Dalian University of Technology,China。
文摘Self-healable and flexible all-in-one self-powering smartsensing devices have recently attracted great attention.Herein,a flexible all-in-one solid-state electronic system of polyvinyl alcohol(PVA)hydrogel-based supercapacitors for self-powering ammonia smartsensors has been fabricated.Self-healing supercapacitors are prepared by integrating polypyrrole(PPy)and boron crosslinked PVA/KCl hydrogel as a sandwich configuration,exhibiting large specific capacitance of 244.81 mF cm^(-2)at 0.47 mA cm^(-2),and good charging/discharging stability of 2000 cycles,while ammonia sensors are realized by a SnO_(2)/PPy-modified conductive PVA hydrogel film,demonstrating an excellent sensing behavior toward NH_(3) vapor under 50 ppb–500 ppm.As a result,selfhealing supercapacitors could well store energy and then self-power sensing unit for remotely real-time detection via a smartphone,acquiring high flexibility of energy-sensing system.With attractive biocompatibility and selfhealing performance toward various environment,this all-in-one flexible energy-smartsensor system would pave the way to novel fabrication process in realization of wearable self-healing smart devices.
基金supported by the National Natural Science Foundation of China(32171342,32471407)the National Key Research and Development Program of China(2023YFC2413600,2022YFB3804303)the Joint Fund for Equipment Pre-research of the Ministry of Education(6141A02022618).
文摘Poly(L-lactic acid)(PLLA)is a biocompatible,biodegradable material with piezoelectric properties,making it a promising candidate for providing self-powered stimulation to accelerate tissue re-pair.Repairs to various tissues,such as bone,cartilage and nerve,necessitate distinct piezoelectric characteristics even from the same material.However,the extensive utilization of PLLA piezoelectric scaffolds in various tissue is hindered by their low and single piezoelectric constants.In this study,PLLA nanofiber membranes with enhanced and adjustable piezoelectric constants(d_(33))were fabricated through oriented electrospinning.By carefully controlling the parameters of the spinning solution,a steady increase in d_(33) values from 0 to 30 pC/N was achieved.This advancement allows tailoring of PLLA nanofiber membranes to meet various piezoelectric requirements of different tissues.As an example of tailoring the optimal piezoelectric constants,we developed PLLA-2-0,PLLA-2-10,PLLA-2-15 and PLLA-2-20 nanofiber membranes with d_(33) values of 0,5,10 and 15 pC/N,respectively.The impact of varying piezoelectric constants of PLLA nanofiber membranes on cellular behavior and repair efficacy were validated through in vitro cellular experiments and in vivo mandibular critical defect repair.The results indicated that PLLA-2-20 demonstrated superior cell proliferation rate up to 130%and an osteogenic differentiation level approximately twice of the control.In addition,PLLA-2-20 significantly promoted cell adhesion and migration,and the cell aspect ratio was about five times higher than that of the control group.In vivo,PLLA-2-20 optimal restorative effects on rat mandibles via endogenous mechanical force-mediated piezoelectric stimulation,leading to complete histological restoration within 8 weeks.These findings highlight the potential of the PLLA membranes with high and adjustable d_(33) by a straightforward process.This study provides a novel approach for the development of highly electroactive membranes tailored to specific tissue repair needs.
基金Natural Science Foundation of China(NSFC,No.22131008)Natural Science Foundation of Tianjin(No.22JCYBJC00500)the Haihe Laboratory of Sustainable Chemical Transformations for financial support.
文摘Possessing excellent mechanical properties,a high-coverage slide-ring conductive gel is constructed by in situ polymerization ofα-cyclodextrin(α-CD)polyrotaxane(PR)and 1-vinyl-3-ethylimidazolium bromide([VEIM]Br)ionic liquid(IL),using 1-ethyl-3-methylimidazolium bromide([EMIM]Br)IL as solvent.Benefiting from the compatibility of ILs and alkene-PR,the cross-linked network slide-ring gel not only maintains excellent conductivity(1.52×10^(−2) S/m),but also has effectively improved mechanical properties(513%fracture strain,0.713 MPa fracture stress,211 kPa elastic modulus and 1366 kJ/m^(3) toughness)and adhesive properties(472.3±25.9 kPa).The supramolecular gel can be used as a strain sensor to efficiently monitor deformation signals in real-time at least 200 times.Especially,the slide-ring gel can self-power generated by triboelectric effect and electrostatic induction between the skin layer and the polydimethylsiloxane(PDMS)layer that encapsulates the gel,achieving reversible and durable motion sensing,which provides a convenient pathway for constructing supramolecular self-powered flexible electronic materials.
基金financial support from the National Key Research and Development Program of China(2022YFB3804905)National Natural Science Foundation of China(22375047,22378068,and 22378071)+1 种基金Natural Science Foundation of Fujian Province(2022J01568)111 Project(No.D17005).
文摘Advanced healthcare monitors for air pollution applications pose a significant challenge in achieving a balance between high-performance filtration and multifunctional smart integration.Electrospinning triboelectric nanogenerators(TENG)provide a significant potential for use under such difficult circumstances.We have successfully constructed a high-performance TENG utilizing a novel multi-scale nanofiber architecture.Nylon 66(PA66)and chitosan quaternary ammonium salt(HACC)composites were prepared by electrospinning,and PA66/H multiscale nanofiber membranes composed of nanofibers(≈73 nm)and submicron-fibers(≈123 nm)were formed.PA66/H multi-scale nanofiber membrane as the positive electrode and negative electrode-spun PVDF-HFP nanofiber membrane composed of respiration-driven PVDF-HFP@PA66/H TENG.The resulting PVDF-HFP@PA66/H TENG based air filter utilizes electrostatic adsorption and physical interception mechanisms,achieving PM_(0.3)filtration efficiency over 99%with a pressure drop of only 48 Pa.Besides,PVDF-HFP@PA66/H TENG exhibits excellent stability in high-humidity environments,with filtration efficiency reduced by less than 1%.At the same time,the TENG achieves periodic contact separation through breathing drive to achieve self-power,which can ensure the long-term stability of the filtration efficiency.In addition to the air filtration function,TENG can also monitor health in real time by capturing human breathing signals without external power supply.This integrated system combines high-efficiency air filtration,self-powered operation,and health monitoring,presenting an innovative solution for air purification,smart protective equipment,and portable health monitoring.These findings highlight the potential of this technology for diverse applications,offering a promising direction for advancing multifunctional air filtration systems.
基金Project supported by the Joints Fund of the National Natural Science Foundation of China(Grant No.U23A20349)the Young Scientists Fund of the National Natural Science Foundation of China(Grant Nos.62204126,62305171,62304113)。
文摘With the rapid advancement of optoelectronic technology,high-performance photodetectors are increasingly in demand in fields such as environmental monitoring,optical communication,and defense systems,where ultraviolet detection is critical.However,conventional semiconductor materials suffer from limited UV-visible detection capabilities owing to their narrow bandgaps and high dark currents.To address these challenges,wide-bandgap semiconductors have emerged as promising alternatives.Here,we fabricated a horizontally structured n–n heterojunction photodetector by growingβ-Ga_(2)O_(3) on Si–GaN via plasma-enhanced chemical vapor deposition.The device exhibits a self-powered photocurrent of 3.5 nA at zero bias,enabled by the photovoltaic effect of the space charge region.Under 254-nm and 365-nm illumination,it exhibits rectification behavior,achieving a responsivity of 0.475 m A/W(0 V,220??W/cm~2 at 254 nm)and 257.6 mA/W(-5 V),respectively.Notably,the photodetector demonstrates a high photocurrent-to-dark current ratio of 10~5 under-5-V bias,highlighting its potential for self-powered and high-performance UV detection applications.
基金supported by the Research Platform for biomedical and Health Technology, NUS (Suzhou) Research Institute (RP-BHT-Prof. LEE Chengkuo)RIE Advanced Manufacturing and Engineering (AME) Programmatic Grant (Grant A18A4b0055)+1 种基金RIE 2025-Industry Alignment Fund – Industry Collaboration Projects (IAF-ICP) (Grant I2301E0027)Reimagine Research Scheme projects, National University of Singapore, A-0009037-03-00 and A-0009454-01-00 and Reimagine Research Scheme projects, National University of Singapore, A-0004772-00-00 and A-0004772-01-00。
文摘Smart farming with outdoor monitoring systems is critical to address food shortages and sustainability challenges.These systems facilitate informed decisions that enhance efficiency in broader environmental management.Existing outdoor systems equipped with energy harvesters and self-powered sensors often struggle with fluctuating energy sources,low durability under harsh conditions,non-transparent or non-biocompatible materials,and complex structures.Herein,a multifunctional hydrogel is developed,which can fulfill all the above requirements and build selfsustainable outdoor monitoring systems solely by it.It can serve as a stable energy harvester that continuously generates direct current output with an average power density of 1.9 W m^(-3)for nearly 60 days of operation in normal environments(24℃,60%RH),with an energy density of around 1.36×10^(7)J m^(-3).It also shows good self-recoverability in severe environments(45℃,30%RH)in nearly 40 days of continuous operation.Moreover,this hydrogel enables noninvasive and self-powered monitoring of leaf relative water content,providing critical data on evaluating plant health,previously obtainable only through invasive or high-power consumption methods.Its potential extends to acting as other self-powered environmental sensors.This multifunctional hydrogel enables self-sustainable outdoor systems with scalable and low-cost production,paving the way for future agriculture.
基金supported by the National Natural Science Foundation of China(Nos.12172248,12302022,12021002,and 12132010)the Tianjin Research Program of Application Foundation and Advanced Technology of China(No.23JCZDJC00950)。
文摘Belt conveyors are extensively utilized in mining and power industries.In a typical coal mine conveyor system,coal is transported over distances exceeding 2 km,involving more than 20000 idlers,which far exceeds a reasonable manual inspection capacity.Given that idlers typically have a lifespan of 1-2 years,there is an urgent need for a rapid,cost-effective,and intelligent safety monitoring system.However,current embedded systems face prohibitive replacement costs,while conventional monitoring technologies suffer from inefficiency at low rotational speeds and lack systematic structural optimization frameworks for diverse idler types and parameters.To address these challenges,this paper introduces an integrated,on-site detachable self-powered idler condition monitoring system(ICMS).This system combines energy harvesting based on the magnetic modulation technology with wireless condition monitoring capabilities.Specifically,it develops a data-driven model integrating convolutional neural networks(CNNs) with genetic algorithms(GAs).The conventional testing results show that the data-driven model not only significantly accelerates the parameter response time,but also achieves a prediction accuracy of 92.95%.The in-situ experiments conducted in coal mines demonstrate the system's reliability and monitoring functionality under both no-load and fullload conditions.This research provides an innovative self-powered condition monitoring solution and develops an efficient data-driven model,offering feasible online monitoring approaches for smart mine construction.
基金supported by the China Postdoctoral Science Foundation(No.2023M732344)the National Natural Science Foundation of China(Nos.51973119,52327802,52173078)+4 种基金Shenzhen Key Laboratory of Photonics and Biophotonics(ZDSYS20210623092006020)Shenzhen Key Laboratory for Low-carbon Natural Science Foundation of Guangdong Province(No.2024A1515010639)Construction Material and Technology(No.ZDSYS20220606100406016)National Key Laboratory of Green and Long-Life Road Engineering in Extreme Environment(Shenzhen)(No.868-000003010103)Joint Funds of Ministry of Education(No.8091B022225).
文摘Self-regulating heating and self-powered flexibility are pivotal for future wearable devices.However,the low energy-conversion rate of wearable devices at low temperatures limits their application in plateaus and other environments.This study introduces an azopolymer with remarkable semicrystallinity and reversible photoinduced solid-liquid transition ability that is obtained through copolymerization of azoben-zene(Azo)monomers and styrene.A composite of one such copolymer with an Azo:styrene molar ratio of 9:1(copolymer is denoted as PAzo9:1-co-polystyrene(PS))and nylon fabrics(NFs)is prepared(composite is denoted as PAzo9:1-co-PS@NF).PAzo9:1-co-PS@NF exhibits hydrophobicity and high wear resistance.Moreover,it shows good responsiveness(0.624 s^(−1))during isomerization under solid ultraviolet(UV)light(365 nm)with an energy density of 70.6 kJ kg^(−1).In addition,the open-circuit voltage,short-circuit current and quantity values of PAzo9:1-co-PS@NF exhibit small variations in a temperature range of−20℃ to 25℃ and remain at 170 V,5 μA,and 62 nC,respectively.Notably,the involved NFs were cut and sewn into gloves to be worn on a human hand model.When the model was exposed to both UV radiation and friction,the temperature of the finger coated with PAzo9:1-co-PS was approximately 6.0°C higher than that of the other parts.Therefore,developing triboelectric nanogenerators based on the in situ photothermal cycles of Azo in wearable devices is important to develop low-temperature self-regulating heating and self-powered flexible devices for extreme environments.
基金supported by the Shanghai Collaborative Innovation Centre for Tumour Energy Therapy Technology and Equipment。
文摘Today,energy is essential for every aspect of human life,including clothing,food,housing and transportation.However,traditional energy resources are insufficient to meet our modern needs.Self-powered sensing devices emerge as promising alternatives,offering sustained operation without relying on external power sources.Leveraging advancements in materials and manufacturing research,these devices can autonomously harvest energy from various sources.In this review,we focus on the current landscape of self-powered wearable sensors,providing a concise overview of energy harvesting technologies,conversion mechanisms,structural or material innovations,and energy storage platforms.Then,we present experimental advances in different energy sources,showing their underlying mechanisms,and the potential for energy acquisition.Furthermore,we discuss the applications of self-powered flexible sensors in diverse fields such as medicine,sports,and food.Despite significant progress in this field,widespread commercialization will necessitate enhanced sensor detection abilities,improved design factors for adaptable devices,and a balance between sensitivity and standardization.
基金supported by the National Natural Science Foundation of China (No. 62204079)the Science and Technology Development Project of Henan Province (Nos.202300410048, 202300410057)+2 种基金the China Postdoctoral Science Foundation (No. 2022M711037)the Intelligence Introduction Plan of Henan Province in 2021 (No. CXJD2021008)Henan University Fund。
文摘Quantum dot(QD)-based infrared photodetector is a promising technology that can implement current monitoring,imaging and optical communication in the infrared region. However, the photodetection performance of self-powered QD devices is still limited by their unfavorable charge carrier dynamics due to their intrinsically discrete charge carrier transport process. Herein, we strategically constructed semiconducting matrix in QD film to achieve efficient charge transfer and extraction.The p-type semiconducting CuSCN was selected as energy-aligned matrix to match the n-type colloidal PbS QDs that was used as proof-of-concept. Note that the PbS QD/CuSCN matrix not only enables efficient charge carrier separation and transfer at nano-interfaces but also provides continuous charge carrier transport pathways that are different from the hoping process in neat QD film, resulting in improved charge mobility and derived collection efficiency. As a result, the target structure delivers high specific detectivity of 4.38 × 10^(12)Jones and responsivity of 782 mA/W at 808 nm, which is superior than that of the PbS QD-only photodetector(4.66 × 10^(11)Jones and 338 mA/W). This work provides a new structure candidate for efficient colloidal QD based optoelectronic devices.
基金supported by the National Natural Science Foundation of China(Grant Nos.52192610 and 52192613)the National Key R&D Project from the Minister of Science and Technology(No.2021YFA1201601)the CAS-TWAS President’s Fellow-ship(A.B).
文摘β-Ga_(2)O_(3),as one of the important 4th generation semiconductors,is widely used in solar-blind ultraviolet(UV)detectors with a short detection range of 200-280 nm benefiting from its ultra-wide bandgap,strong radiation resistance,and excellent chemical and thermal stabilities.Here,a self-powered photodetector(PD)based on an Ag/β-Ga_(2)O_(3) Schottky heterojunction was designed and fabricated.Through a subtle design of electrodes,the pyro-phototronic effect was discovered,which can be coupled to the common photovoltaic effect and further enhance the performance of the PD.Compared to traditional Ga_(2)O_(3)-based PD,the as-used PD exhibited a self-driving property and a broadband response beyond the bandgap lim-itations,ranging from 200 nm(deep UV)to 980 nm(infrared).Moreover,the photoresponse time was greatly shrunk owing to the coupling effect.Under laser irradiation,with a wavelength of 450 nm and a power density of 8 mW cm-2,the photocurrent could be improved by around 41 times compared with the sole photovoltaic effect.Besides,the performances of the Schottky PD were enhanced at both high and low temperatures.The device also possessed long-term working stability.This paper not only re-veals basic physics lying in the 4th generation semiconductor Ga_(2)O_(3) but also sheds light on the multi-encryption transmission of light information using this PD.
文摘This study explores how the performance of triboelectric nanogenerators can be enhanced by incorporating Fe_(3)O_(4) nanoparticles into nylon films using a spray coating technique.Five triboelectric nanogenerator prototypes were created:one with regular nylon and four with nylon/Fe_(3)O_(4) nanocomposites featuring varying nanoparticle densities.The electrical output,measured by open-circuit voltage and short-circuit current,showed significant improvements in the nanocomposite-based triboelectric nanogenerators compared to the nylon-only triboelectric nanogenerator.When a weak magnetic field was applied during nanocomposite preparation,the maximum voltage and current reached 56.3 V and 4.62μA,respectively.Further analysis revealed that the magnetic field during the drying process aligned the magnetic domains,boosting output efficiency.These findings demonstrate the potential of Fe_(3)O_(4) nanoparticles to enhance electrostatic and magnetic interactions in triboelectric nanogenerators,leading to improved energy-harvesting performance.This approach presents a promising strategy for developing high-performance triboelectric nanogenerators for sustainable energy and sensor applications.
基金financially supported by the National Natural Science Foundation of China(Nos.22435005,22193042,21921001,22305105,52202194,22201284)Natural Science Foundation of Jiangxi Province(No.20224BAB213003)+1 种基金the Natural Science Foundation of Fujian Province(No.2023J05076)Jiangxi Provincial Education Department Science and Technology Research Foundation(No.GJJ2200384)。
文摘Two-dimensional perovskite ferroelectric which strongly couple ferroelectricity with semiconducting properties are promising candidates for optoelectronic applications.However,it is still a great challenge to fabricate self-powered broadband photodetectors with low detection limit.Herein,we successfully realized self-powered broadband photodetection with low detection limit by using a trilayered perovskite ferroelectric(BA)_(2)EA_(2)Pb_(3)I_(10)(1,BA=n-butylamine,EA=ethylamine).Giving to its large spontaneous polarization(5.6μC/cm^(2)),1 exhibits an open-circuit voltage of 0.25 V which provide driving force to separate carriers.Combining with its low dark current(~10^(-14)A)and narrow bandgap(Eg=1.86 e V),1 demonstrates great potential on detecting the broadband weak lights.Thus,a prominent photodetection performance with high open-off ratio(~10^(5)),outstanding responsivity(>10 m A/W),and promising detectivity(>1011Jones),as well as the low detecting limit(~nW/cm^(2))among the wide wavelength from 377 nm to637 nm was realized based on the single crystal of 1.This work demonstrates the great potential of 2D perovskite ferroelectric on self-powered broadband photodetectors.
基金Liming Gao acknowledges funding from the National Natural Science Foundation of China(No.61727805).
文摘The rise of smart wearable devices has driven the demand for flexible,high-performance optoelectronic devices with low power and easy high-density integration.Emerging Two-dimensional(2D)materials offer promising solutions.However,the use of 3D metal in traditional 2D devices often leads to Fermi-level pinning,compromising device performance.2D metallic materials,such as graphene and 2H-phase NbSe_(2),present a new avenue for addressing this issue and constructing high-performance,low-power photodetectors.In this work,we designed an all-2D asymmetric contacts photodetector using Gr and NbSe_(2)as electrodes for the 2D semiconductor WSe_(2).The asymmetric Schottky barriers and built-in electric fields facilitated by this architecture resulted in outstanding photovoltaic characteristics and self-powered photodetection.Under zero bias,the device exhibited a responsivity of 287 mA/W,a specific detectivity of 5.3×10^(11)Jones,and an external quantum efficiency of 88%.It also demonstrated an ultra-high light on/offratio(1.8×10^(5)),ultra-fast photoresponse speeds(80/72μs),broad-spectrum responsiveness(405980 nm),and exceptional cycling stability.The applications of the Gr/WSe_(2)/NbSe_(2)heterojunction in imaging and infrared optical communication have been explored,underscoring its significant potential.This work offers an idea to construct all-2D ultrathin optoelectronic devices.
基金support for this research was provided by the High-Level Scientific Research Cultivation Project at Hubei Minzu University,with the grant identifier PY22001the Guiding Projects from the Department of Education in Hubei Province,identified by the grant number B2018088.
文摘Recently,self-powered ultraviolet photodetectors(UV PDs)based on SnO_(2)have gained increasing interest due to its feature of working continuously without the need for external power sources.Nevertheless,the production of the majority of these existing UV PDs necessitates additional manufacturing stages or intricate processes.In this work,we present a facile,cost-effective approach for the fabrication of a self-powered UV PD based on p-Si/n-SnO_(2)junction.The self-powered device was achieved simply by integrating a p-Si substrate with a n-type SnO_(2)microbelt,which was synthesized via the chemical vapor deposition(CVD)method.The high-quality feature,coupled with the belt-like shape of the SnO_(2)microbelt enables the favorable contact between the n-type SnO_(2)and p-type silicon.The built-in electric field created at the interface endows the self-powered performance of the device.The p-Si/n-SnO_(2)junction photodetector demonstrated a high responsivity(0.12 mA/W),high light/dark current ratio(>103),and rapid response speed at zero bias.This method offers a practical way to develop cost-effective and high-performance self-powered UV PDs.
基金supported by the National Natural Science Foundation of China(Project no.51973120)the Natural Science Foun-dation of Guangdong Province(No.2019A1515010613)+1 种基金the Shenzhen Science and Technology Research Grant(Nos.JCYJ20170818093417096 and JCYJ20180305125649693)the Shenzhen Science and Technology Program(No.20220809111527001).
文摘Due to its ability to convert body heat into electricity,organic thermoelectric material is considered a promising and smart maintenance-free power source to charge wearable electronics.However,developing flexible n-type organic thermoelectric materials and wearable p/n junction thermoelectric devices remains challenging.In this work,two insulated polyamides(PA6 and PA66)that have been widely used as fiber materials are employed as novel dopants for converting p-type single-walled carbon nanotubes(SWCNTs)to n-type thermoelectric materials.Because of the electron transferability of the amide group,polyamide-doped SWCNTs exhibit excellent thermopower values as large as-56.0μV K^(-1) for PA66,and-54.5μV K^(-1) for PA6.Thermoelectric devices with five p/n junctions connected in series are fabricated.The testing device produces a thermoelectric voltage of 43.1 mV and generates 1.85μW thermoelectric power under temperature gradients of approximately 80 K.Furthermore,they display charming capability for temperature recognition and monitoring human activities as sensors.These promising results suggest that the flexible polyamide-doped SWCNT composites herein have high application potential as wearable thermoelectric electronics.
基金supported by the National Key Research and Development Program of China(2023YFB3610500)National Natural Science Foundation of China(62104110,62374094)+1 种基金the Project funded by China Postdoctoral Science Foundation(2023T160332)Natural Science Foundation of Nanjing University of Posts and Telecommunications(NY224084,NY224131).
文摘Low power consumption,high responsivity,and self-powering are key objectives for photoelectrochemical ultravio-let detectors.In this research,In-dopedα-Ga_(2)O_(3) nanowire arrays were fabricated on fluorine-doped tin oxide(FTO)substrates through a hydrothermal approach,with subsequent thermal annealing.These arrays were then used as photoanodes to con-struct a ultraviolet(UV)photodetector.In doping reduced the bandgap ofα-Ga_(2)O_(3),enhancing its absorption of UV light.Conse-quently,the In-dopedα-Ga_(2)O_(3) nanowire arrays exhibited excellent light detection performance.When irradiated by 255 nm deep ultraviolet light,they obtained a responsivity of 38.85 mA/W.Moreover,the detector's response and recovery times are 13 and 8 ms,respectively.The In-dopedα-Ga_(2)O_(3) nanowire arrays exhibit a responsivity that is about three-fold higher than the undoped one.Due to its superior responsivity,the In-doped device was used to develop a photoelectric imaging system.This study demonstrates that dopingα-Ga_(2)O_(3) nanowire with indium is a potent approach for optimizing their photoelectrochemi-cal performance,which also has significant potential for optoelectronic applications.
基金supported by the National Natural Science Foundation of China(Nos.22193042,22125110,22075285,52473283,21921001,U21A2069)the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(No.ZDBS-LY-SLH024)the Youth Innovation Promotion of Chinese Academy of Sciences(No.2020307)。
文摘Polar semiconductors,particularly the emerging polar two-dimensional(2D)halide perovskites,have motivated immense interest in diverse photoelectronic devices due to their distinguishing polarizationgenerated photoelectric effects.However,the constraints on the organic cation's choice are still subject to limitations of polar 2D halide perovskites due to the size of the inorganic pocket between adjacent corner-sharing octahedra.Herein,a mixed spacer cation ordering strategy is employed to assemble a polar 2D halide perovskite NMAMAPb Br_(4)(NMPB,NMA is N-methylbenzene ammonium,MA is methylammonium)with alternating cation in the interlayer space.Driven by the incorporation of a second MA cation,the perovskite layer transformed from a 2D Pb_(7)Br_(24)anionic network with corner-and face-sharing octahedra to a flat 2D PbBr_(4)perovskite networks only with corner-sharing octahedra.In the crystal structure of NMPB,the asymmetric hydrogen-bonding interactions between ordered mixed-spacer cations and 2D perovskite layers give rise to a second harmonic generation response and a large polarization of 1.3μC/cm^(2).More intriguingly,the ordered 2D perovskite networks endow NMPB with excellent self-powered polarization-sensitive detection performance,showing a considerable polarization-related dichroism ratio up to 1.87.The reconstruction of an inorganic framework within a crystal through mixed cation ordering offers a new synthetic tool for templating perovskite lattices with controlled properties,overcoming limitations of conventional cation choice.
基金the Industry-University Cooperation Project in Fujian Province University(No.2022H6020)。
文摘Self-powered neutron detectors(SPNDs)play a critical role in monitoring the safety margins and overall health of reactors,directly affecting safe operation within the reactor.In this work,a novel fault identification method based on graph convolutional networks(GCN)and Stacking ensemble learning is proposed for SPNDs.The GCN is employed to extract the spatial neighborhood information of SPNDs at different positions,and residuals are obtained by nonlinear fitting of SPND signals.In order to completely extract the time-varying features from residual sequences,the Stacking fusion model,integrated with various algorithms,is developed and enables the identification of five conditions for SPNDs:normal,drift,bias,precision degradation,and complete failure.The results demonstrate that the integration of diverse base-learners in the GCN-Stacking model exhibits advantages over a single model as well as enhances the stability and reliability in fault identification.Additionally,the GCN-Stacking model maintains higher accuracy in identifying faults at different reactor power levels.
基金supported by the Engineering Research Centre for Digital Grid Technology for Coordinating New Energy under Grant[Grant number 2021GCZX003]Yunnan Fundamental Research Projects under Grant[Grant number 202301CF070031]+2 种基金Hundred Talents Project 2023 under Grant[Grant number B0201001]2024 Distinctive Innovation Scientific Research Projects for Higher Education Institutions[Grant number 2024KTSCX157]Young Innovative Talent Project under Grant[Grant numbers K0223021,K0224014].
文摘Targeting spontaneous coal combustion during stacking,we developed an efficient heat dissipation&self-supplied wireless temperature measurement system(SPWTM)with gravity heat pipe-thermoelectric integration for dual safety.The heat transfer characteristics and temperature measurement optimization of the system are experimentally investigated and verified in practical applications.The results show that,firstly,the effects of coal pile heat production power and burial depth,along with heat pipe startup and heat transfer characteristics.At 60 cmburial depth,the condensation section dissipates 98%coal pile heat via natural convection.Secondly,for the temperature measurement error caused by the heat pipe heat transfer temperature difference,the correction method of“superimposing the measured value with the heat transfer temperature difference”is proposed,and the higher the coal temperature,the better the temperature measurement accuracy.Finally,the system can quickly(≤1 h)reduce the temperature of the coal pile to the spontaneous combustion point,significantly inhibiting the spontaneous combustion phenomenon,the maximum temperature does not exceed 49.2℃.Meanwhile,it utilizes waste heat to drive thermoelectric power generation,realizing self-supplied,unattended,and long-term accurate temperature measurement and warning.In a word,synergistic active heat dissipation and self-powered temperature monitoring-warning ensure dual coal pile thermal safety.
