This research investigates the application of digital images in military contexts by utilizing analytical equations to augment human visual capabilities.A comparable filter is used to improve the visual quality of the...This research investigates the application of digital images in military contexts by utilizing analytical equations to augment human visual capabilities.A comparable filter is used to improve the visual quality of the photographs by reducing truncations in the existing images.Furthermore,the collected images undergo processing using histogram gradients and a flexible threshold value that may be adjusted in specific situations.Thus,it is possible to reduce the occurrence of overlapping circumstances in collective picture characteristics by substituting grey-scale photos with colorized factors.The proposed method offers additional robust feature representations by imposing a limiting factor to reduce overall scattering values.This is achieved by visualizing a graphical function.Moreover,to derive valuable insights from a series of photos,both the separation and in-version processes are conducted.This involves analyzing comparison results across four different scenarios.The results of the comparative analysis show that the proposed method effectively reduces the difficulties associated with time and space to 1 s and 3%,respectively.In contrast,the existing strategy exhibits higher complexities of 3 s and 9.1%,respectively.展开更多
Fundamental research and practical applications have examined the manipulation of gas bubbles on open surfaces in lowsurface-tension,high-pressure,and high-acidity,-alkalinity,or-salinity environments.However,to the b...Fundamental research and practical applications have examined the manipulation of gas bubbles on open surfaces in lowsurface-tension,high-pressure,and high-acidity,-alkalinity,or-salinity environments.However,to the best of our knowledge,effi cient and general approaches to achieve the smart manipulation of gas bubbles in these harsh environments are limited.Herein,a Fluorinert-infused shape-gradient slippery surface(FSSS)that could eff ectively regulate the behavior of gas bubbles in harsh environments was successfully fabricated.The unique capability of FSSS was mainly attributed to the properties of Fluorinert,which include chemical inertness and incompressibility.The shape-gradient morphology of FSSS could induce asymmetric driving forces to move gas bubbles directionally on open surfaces.Factors infl uencing gas bubble transport on FSSS,such as the apex angle of the slippery surface and the surface tension of the aqueous environment,were carefully investigated,and large apex angles were found to result in large initial transport velocities and short transport distances.Lowering the surface tension of the aqueous environment is unfavorable to bubble transport.Nevertheless,FSSS could transport gas bubbles in aqueous environments with surface tensions as low as 28.5±0.1 mN/m,which is lower than that of many organic solvents(e.g.,formamide,ethylene glycol,and dimethylformamide).In addition,FSSS could also realize the facile manipulation of gas bubbles in various aqueous environments,e.g.,high pressure(~6.8 atm),high acidity(1 mol/L H 2 SO 4),high alkalinity(1 mol/L NaOH),and high salinity(1 mol/L NaCl).The current fi ndings provide a source of knowledge and inspiration for studies on bubble-related interfacial phenomena and contribute to scientifi c and technological developments for controllable bubble manipulation in harsh environments.展开更多
Surface acoustic wave （SAW） sensors and micro-electromechanical system （MEMS） technology provide a promising solution for measurement in harsh environments such as gas turbines. In this paper, a SAW resonator （s...Surface acoustic wave （SAW） sensors and micro-electromechanical system （MEMS） technology provide a promising solution for measurement in harsh environments such as gas turbines. In this paper, a SAW resonator （size： 1107μm× 721 μm） based on the AlN/4H-SiC multilayer structure is designed and simulated. A MEMS-compatible fabrication process is employed to fabricate the resonator. The results show that highly c-axis-oriented AlN thin films deposited on the 4H-SiC substrate are obtained, with that the diffraction peak of AlN is 36.10° and the lowest full width at half maximum （FWHM） value is only 1.19°. The test results of the network analyzer are consistent with the simulation curve, which is very encouraging and indicates that our work is a significant attempt to solve the measurement problems mainly including high temperature stability of sensitive structures and the heat transmission of leads in harsh environments. It is essential to get the best performance of SAW resonator, optimize and characterize the behaviors in high temperatures in future research.展开更多
In many industries,there is a growing demand for semiconductor pressure sensors capable of operating in harsh environments with extremely high and low temperatures and high vibrations.Utilizing the piezoresistive effe...In many industries,there is a growing demand for semiconductor pressure sensors capable of operating in harsh environments with extremely high and low temperatures and high vibrations.Utilizing the piezoresistive effect of heavily doped N-type 4H-SiC,we proposed a family design of eight pressure sensor chip structures featuring different diaphragm shapes of circles and squares,along with different piezoresistor configurations.The 4H-SiC piezoresistive pressure sensor was developed using micro-electromechanical systems(MEMS)technology and encapsulated in a leadless package structure via low-stress connection achieved by glass frit sintering.The 4H-SiC pressure sensor demonstrates impressive performance,exhibiting an accuracy of 0.18%FSO and a temperature tolerance range from−50 to 600°C,with a temperature coefficient of zero output as low as 0.08%/°C at 600°C.Furthermore,the developed sensor shows remarkable stability under conditions of high-temperature vibration coupling.The advancement of this family of 4H-SiC pressure sensors provides a promising solution for pressure measurement in harsh industrial environments.展开更多
Triboelectric nanogenerators(TENG)have emerged as a highly promising energy harvesting technology,attracting significant attention in recent years for their broad applications.Gel-based TENGs,with superior stretchabil...Triboelectric nanogenerators(TENG)have emerged as a highly promising energy harvesting technology,attracting significant attention in recent years for their broad applications.Gel-based TENGs,with superior stretchability and sensitivity,have been widely reported as wearable sensors.However,the traditional hydrogel-based TENGs suffer from freezing at low temperatures and drying at high temperatures,resulting in malfunctions.In this study,we introduce an anti-freezing eutectogel,which uses a deep eutectic solvent(DES),to improve the stability and electrical conductivity of TENGs in harsh environmental conditions.The eutectogel-based TENG(E-TENG)produces an open-circuit voltage of 776 V,a short-circuit current of 1.54μA,and a maximum peak power of 1.1 mW.Moreover,the E-TENG exhibits exceptional mechanical properties with an elongation at a break of 476%under tension.Importantly,it maintains impressive performances across a wide temperature range from−18 to 60℃,with conductivities of 2.15 S/m at−10℃and 1.75 S/m at−18℃.Based on the excellent weight stability of the E-TENG sensor,motion sensing can be achieved in the air,and even underwater.Finally,the versatility of the E-TENG can serve as a wearable sensor,by integrating it with Bluetooth technology.The self-powered E-TENG can monitor various human motion signals in real-time and send the health signals directly to mobile phones.This research paves a new road for the applications of TENGs in harsh environments,offering wireless flexible sensors with real-time health signal monitoring capabilities.展开更多
Recent advancements in passive wireless sensor technology have significantly extended the application scope of sensing,particularly in challenging environments for monitoring industry and healthcare applications.These...Recent advancements in passive wireless sensor technology have significantly extended the application scope of sensing,particularly in challenging environments for monitoring industry and healthcare applications.These systems are equipped with battery-free operation,wireless connectivity,and are designed to be both miniaturized and lightweight.Such features enable the safe,real-time monitoring of industrial environments and support high-precision physiological measurements in confined internal body spaces and on wearable epidermal devices.Despite the exploration into diverse application environments,the development of a systematic and comprehensive research framework for system architecture remains elusive,which hampers further optimization of these systems.This review,therefore,begins with an examination of application scenarios,progresses to evaluate current system architectures,and discusses the function of each component—specifically,the passive sensor module,the wireless communication model,and the readout module—within the context of key implementations in target sensing systems.Furthermore,we present case studies that demonstrate the feasibility of proposed classified components for sensing scenarios,derived from this systematic approach.By outlining a research trajectory for the application of passive wireless systems in sensing technologies,this paper aims to establish a foundation for more advanced,user-friendly applications.展开更多
Microsystems are increasingly being applied in harsh and/or inaccessible environments,but many markets expect the same level of functionality for long periods of time.Harsh environments cover areas that can be subject...Microsystems are increasingly being applied in harsh and/or inaccessible environments,but many markets expect the same level of functionality for long periods of time.Harsh environments cover areas that can be subjected to high temperature,(bio)-chemical and mechanical disturbances,electromagnetic noise,radiation,or high vacuum.In the field of actuators,the devices must maintain stringent accuracy specifications for displacement,force,and response times,among others.These new requirements present additional challenges in the compensation for or elimination of cross-sensitivities.Many state-of-the-art precision devices lose their precision and reliability when exposed to harsh environments.It is also important that advanced sensor and actuator systems maintain maximum autonomy such that the devices can operate independently with low maintenance.The next-generation microsystems will be deployed in remote and/or inaccessible and harsh environments that present many challenges to sensor design,materials,device functionality,and packaging.All of these aspects of integrated sensors and actuator microsystems require a multidisciplinary approach to overcome these challenges.The main areas of importance are in the fields of materials science,micro/nano-fabrication technology,device design,circuitry and systems,(first-level)packaging,and measurement strategy.This study examines the challenges presented by harsh environments and investigates the required approaches.Examples of successful devices are also given.展开更多
Advanced sensing techniques are in big demand for applications in hypersonic wind tunnel harsh environments,such as aero(thermo)dynamics measurements,thermal protection of aircraft structures,air-breathing propulsion,...Advanced sensing techniques are in big demand for applications in hypersonic wind tunnel harsh environments,such as aero(thermo)dynamics measurements,thermal protection of aircraft structures,air-breathing propulsion,light-weighted and highstrength materials,etc.In comparison with traditional electromechanical or electronic sensors,the fiber optic sensors have relatively high potential to work in hypersonic wind tunnel,due to the capability of responding to a wide variety of parameters,high resolution,miniature size,high resistant to electromagnetic and radio frequency interferences,and multiplexing,and so on.This article has classified and summarized the research status and the representative achievement on the fiber optic sensing technologies,giving special attention to the summary of research status on the popular Fabry-Perot interferometric,fiber Bragg gratings and(quasi)distributed fiber optic sensors working in hypersonic wind tunnel environment,and discussed the current problems in special optical fiber sensing technologies.This article would be regarded as reference for the researchers in hypersonic wind tunnel experiment field.展开更多
1 The Inuit's remarkable ability to thrive(蓬勃发展)in one of Earth's toughest environments hasn't happened by chance.Their complex system of traditions,passed down through countless generations,represents...1 The Inuit's remarkable ability to thrive(蓬勃发展)in one of Earth's toughest environments hasn't happened by chance.Their complex system of traditions,passed down through countless generations,represents far more than mere survival strategies-it's a highly developed blueprint for living in harmony with the Arctic's unforgiving landscape.展开更多
We present the fabrication and testing of a silicon carbide （SiC） balanced mass doublended tuning fork that survives harsh environments without compromising the device strain sensitivity and resolution bandwidth. Th...We present the fabrication and testing of a silicon carbide （SiC） balanced mass doublended tuning fork that survives harsh environments without compromising the device strain sensitivity and resolution bandwidth. The device features a material stack that survives corrosive environments and enables high-temperature operation. To perform hightemperature testing, a specialized setup was constructed that allows the tuning fork to be characterized using traditional silicon electronics. The tuning fork has been operated at 600°C in the presence of dry steam for short durations. This tuning fork has also been tested to 64 000 G using a hard-launch, soft-catch shock implemented with a light gas gun. However, the device still has a strain sensitivity of 66 Hz/μe and strain resolution of 0. 045 μe in a 10 kHz bandwidth. As such, this balanced-mass double-ended tuning fork can be used to create a variety of different sensors including strain gauges, accelerometers, gyroscopes, and pressure transducers. Given the adaptable fabrication process flow, this device could be useful to micro-electro-mechanical systems （MEMS） designers creating sensors for a variety of different applications.展开更多
Defects engineering is an effective strategy for manipulating electromagnetic parameters and enhancing electromagnetic wave(EMW)absorption capacity.However,the relationship between them is not clear,especially in soli...Defects engineering is an effective strategy for manipulating electromagnetic parameters and enhancing electromagnetic wave(EMW)absorption capacity.However,the relationship between them is not clear,especially in solid solution structures.In this work,a series of(Cr_(1-x)V_(x))_(2)AlC MAX phase solid solutions with layered structure were prepared via tuning the ratio of Cr and V to explore their EMW absorption performance.The experimental results indicated that the doping of V atoms at the M-site could effectively regulate its impedance matching and EMW absorption properties by introducing appropriate numbers of defects in the crystal,such as twin boundaries,dislocations and lattice distortions.Among them,if Cr:V=3:1,Cr_(1.5)V_(0.5)AlC,as radar absorption materials,could reach a strong reflection loss of-51.8 dB at the frequency of 12.8 GHz under an ultra-thin thickness of 1.3 mm.The reflection loss value could attain-10 dB in a wide frequency range of 2.7-18 GHz and thickness range of 1-5 mm.In addition,after high temperature and acid-alkali immersion treatment,this sample still had good EMW absorption capability,and the effective absorption bandwidth was enhanced from 2.3 to 2.6 GHz after concentrated acid immersion or 3.1 GHz after concentrated alkali immersion.This work has great reference significance for the research and development of high-performance MAX-based EMW absorption materials in harsh environments.展开更多
Conformal thin-film sensors enable precise monitoring of the operating conditions of components in extreme environments.However,the development of these sensors encounters major challenges,especially in uniformly appl...Conformal thin-film sensors enable precise monitoring of the operating conditions of components in extreme environments.However,the development of these sensors encounters major challenges,especially in uniformly applying multiple film layers on complex metallic surfaces and accurately capturing diverse operational parameters.This work reports a multi-sensor design and multi-layer additive manufacturing process targeting spherical metallic substrates.The proposed high-temperature dip-coating and self-leveling fabrication process achieves high-temperature thin-film coatings with excellent uniformity,high-temperature electrical insulation,and adhesion properties.The fabricated Ag/Pt thin film thermocouple arrays and a heat flux sensor exhibit a maximum temperature resistance of up to 960℃,with thermoelectric potential outputs and hightemperature resistance closely mirroring those of wire-based Ag/Pt thermocouples.Harsh environmental testing was conducted using high-power lasers and a flame gun.The results show that the array of thin-film conformal thermocouples more accurately reflected temperature changes at different points on a spherical surface.The heat flux sensors achieve responses within 95 ms and with-stand environments with heat fluxes over 1.2 MW/m^(2).The proposed multi-sensor design and fabrication method offers promising monitoring applications in harsh environments,including aerospace and nuclear power.展开更多
The main objective of this paper is to evaluate the seismic response of buildings of typical reinforced concrete frames when concrete starts to deteriorate gradually and to make a comparison between the base shear and...The main objective of this paper is to evaluate the seismic response of buildings of typical reinforced concrete frames when concrete starts to deteriorate gradually and to make a comparison between the base shear and the displacement at different stages of earthquake loading. Typical 5, 15, 20 and 30-storey reinforced concrete frames have been designed for seismicity according to the recently adopted seismic code in Abu Dhabi, ACI 318-08/IBC 2009 code. A pushover analysis has been performed to these four buildings by using SAP 2000. Twenty-four models have been created (6 models for each building) by decreasing the concrete strength gradually from 4000 psi (281 kg/cm<sup>2</sup>) to 1500 psi (105 kg/cm<sup>2</sup>). This is to simulate the effect of harsh environment on the strength of concrete in existing buildings.展开更多
Arid soils where water and nutrients are scarce occupy over 30% of the Earth's total surface. However, the microbial autotrophy in the harsh environments remains largely unexplored. In this study, the abundance an...Arid soils where water and nutrients are scarce occupy over 30% of the Earth's total surface. However, the microbial autotrophy in the harsh environments remains largely unexplored. In this study, the abundance and diversity of autotrophic bacteria were investigated, by quantifying and profiling the large subunit genes of ribulose-1,5-bisphosphate carboxylase/oxygenase(Ru Bis CO) form I(cbb L) responsible for CO2 fixation, in the arid soils under three typical plant types(Haloxylon ammodendron, Cleistogenes chinensis,and Reaumuria soongorica) in Northwest China. The bacterial communities in the soils were also characterized using the 16 S r RNA gene. Abundance of red-like autotrophic bacteria ranged from 3.94 × 105 to 1.51 × 106 copies g-1dry soil and those of green-like autotrophic bacteria ranged from 1.15 × 106 to 2.08 × 106 copies g-1dry soil. Abundance of both red- and green-like autotrophic bacteria did not significantly differ among the soils under different plant types. The autotrophic bacteria identified with the cbb L gene primer were mainly affiliated with Alphaproteobacteria, Betaproteobacteria and an uncultured bacterial group, which were not detected in the 16 S r RNA library. In addition, 25.9% and 8.1% of the 16 S r RNA genes were affiliated with Cyanobacteria in the soils under H. ammodendron and R. soongorica, respectively. However, no Cyanobacteria-affiliated cbb L genes were detected in the same soils. The results suggested that microbial autotrophic CO2 fixation might be significant in the carbon cycling of arid soils, which warrants further exploration.展开更多
Deep penetration into the Earth’s interior and direct monitoring of weak changes in physical fields and their cumulative processes and effects in the deep Earth can enhance the identification of deep Earth targets an...Deep penetration into the Earth’s interior and direct monitoring of weak changes in physical fields and their cumulative processes and effects in the deep Earth can enhance the identification of deep Earth targets and deepen the degree of knowledge of the details of the deep Earth structure and deep processes(Moskvitch,2014),which is important for promoting the development of Earth system science.展开更多
A novel efficient track initiation method is proposed for the harsh underwater target tracking environment(heavy clutter and large measurement errors): track splitting, evaluating, pruning and merging method(TSEPM). T...A novel efficient track initiation method is proposed for the harsh underwater target tracking environment(heavy clutter and large measurement errors): track splitting, evaluating, pruning and merging method(TSEPM). Track initiation demands that the method should determine the existence and initial state of a target quickly and correctly.Heavy clutter and large measurement errors certainly pose additional difficulties and challenges, which deteriorate and complicate the track initiation in the harsh underwater target tracking environment. There are three primary shortcomings for the current track initiation methods to initialize a target:(a) they cannot eliminate the turbulences of clutter effectively;(b) there may be a high false alarm probability and low detection probability of a track;(c) they cannot estimate the initial state for a new confirmed track correctly. Based on the multiple hypotheses tracking principle and modified logic-based track initiation method, in order to increase the detection probability of a track,track splitting creates a large number of tracks which include the true track originated from the target. And in order to decrease the false alarm probability, based on the evaluation mechanism, track pruning and track merging are proposed to reduce the false tracks. TSEPM method can deal with the track initiation problems derived from heavy clutter and large measurement errors, determine the target’s existence and estimate its initial state with the least squares method. What’s more, our method is fully automatic and does not require any kind manual input for initializing and tuning any parameter. Simulation results indicate that our new method improves significantly the performance of the track initiation in the harsh underwater target tracking environment.展开更多
Polymer-derived ceramics(PDCs)pyrolyzed at high temperatures are promising electromagnetic wave(EMW)absorption materials for aerodynamically heated parts of aircraft under harsh environments.Nev-ertheless,high-tempera...Polymer-derived ceramics(PDCs)pyrolyzed at high temperatures are promising electromagnetic wave(EMW)absorption materials for aerodynamically heated parts of aircraft under harsh environments.Nev-ertheless,high-temperature pyrolysis results in a significant increase of electrical and dielectric proper-ties of the ceramics,causing extensive reflection of EMW.To address this challenge,boron nitride-coated carbon nanotubes(BN@CNTs)were fabricated and introduced into polymer-derived SiC(PDC-SiC)by py-rolyzing its precursor higher than 1200℃to form SiC-BN@CNT ceramic composites.The fabricated com-posites with 3 wt.%BN@CNTs pyrolyzed at 1200℃have an effective absorption bandwidth(EAB)of 4.2 GHz(8.2-12.4 GHz)at a thickness of 3.4 mm and the minimum reflection loss(RL min)of-57.20 dB.The ultra-broad EAB of 12.62 GHz(5.38-18 GHz)is obtained by simulation through periodic structure design-ing.The RL of the metamaterials was also measured using an arch testing method at a frequency range of 2-18 GHz and an EAB of 11.52 GHz(6.48-18 GHz)is obtained.The excellent absorption is attributed to the BN layer that limits the electrical conduction of the ceramic composites while retaining the high loss of CNTs.The introduction of BN@CNTs causes the refinement of SiC grains,which provides plenty of interfaces and enhances the interface polarization loss.This work successfully solves the problem that PDCs pyrolyzed at elevated temperatures cannot be used as EMW absorption materials by applying BN coating on CNTs served as absorbers for PDC-SiC.The results of this work greatly broaden the application scope of the PDC systems for EMW absorption.展开更多
Floating photovoltaic(FPV)technology is emerging as a highly promising approach to accelerate decarbonization of the global economy,due to its higher power generation efficiency and lower land occupation.With the rapi...Floating photovoltaic(FPV)technology is emerging as a highly promising approach to accelerate decarbonization of the global economy,due to its higher power generation efficiency and lower land occupation.With the rapid development of FPV technology,the mechanical performance degradation of key components caused by the harsh marine environment has become a pressing issue,as it significantly contributes to failure behavior observed in FPV systems.A comprehensive compilation of the mechanical performance of key components in FPV systems is also currently unavailable.Here,the mechanical behavior of each structural component in FPV systems under harsh marine environments is systematically reviewed.It further emphasizes the synergistic effects of mechanical performance degradation among different components on the overall system.The drop-off rate(v)of normalized elongation at break(EAB)of polymer under the synergistic effect of various environmental factors increases from 7.5×10^(−4)h^(−1)to 21.8×10^(−4)h^(−1)compared with the single environmental stress.Moreover,the development of novel materials and innovative mechanical structures applied in FPV systems to enhance mechanical performance is discussed.The novel flexible PV modules applied in FPV systems minimize the loads acting on the mooring lines by 80%and increase power generation by 5%.Notably,this paper provides a theoretical foundation for developing standards of FPV systems,especially the establishment of standards related to the synergistic effects of the mechanical performance degradation of different key components on FPV systems.展开更多
The triboelectric nanogenerator(TENG)offers a novel approach to harness mechanical energy continuously and sustainably.It has emerged as a leading technology for converting mechanical energy into electricity.The deman...The triboelectric nanogenerator(TENG)offers a novel approach to harness mechanical energy continuously and sustainably.It has emerged as a leading technology for converting mechanical energy into electricity.The demand for self-powered wearable microelectronics and energy generation in extreme conditions underscores the need for efficient high-temperature operatable TENGs(HTO-TENGs).However,the operating environment temperature not only affects the storage and dissipation of electrons during triboelectrification,leading to decreased output performance of TENG and instability at high temperatures,but also damage to the mechanical stability and effective defects in most tribomaterials,resulting in a further reduction in TENG’s effective output power.Moreover,the unstable material properties of the triboelectric layer at high temperatures also restrict the use of the TENG in harsh environments.Therefore,it is imperative to consider the structural durability and electrical output stability of TENG when applying it in challenging working environments.This review aims to bridge this gap by providing a comprehensive overview of the current state and research advancements in HTO-TENG for the first time.Finally,this review presents insights into future research prospects and proposes design strategies to facilitate the rapid development of the field.展开更多
In situ temperature monitoring has become extremely imperative in high-temperature harsh environments and polymer-derived ceramics(PDCs)as sensing materials have attracted great attention.However,the stability and oxi...In situ temperature monitoring has become extremely imperative in high-temperature harsh environments and polymer-derived ceramics(PDCs)as sensing materials have attracted great attention.However,the stability and oxidation/corrosion resistance of PDCs cannot be simultaneously achieved at the moment,limiting their practical application.Herein,polymer-derived SiAlBCN ceramics were synthesized via polymer conversion method under different pyrolysis temperatures.Their microstructure evolution,high temperature sensing properties,and stability were investigated in detail.The results show that the amorphous SiAlBCN phase grows more orderly and the size of the free carbon phase enlarges with the increasing temperature.The defect concentration displays a decreasing tendency.Concurrently,the SiAlBCN ceramics as sensing materials exhibit a good temperature-resistance property from roo temperature to 1100℃.The fabricated SiAlBCN temperature sensor possesses excellent stability,repeatability,and accuracy.Moreover,SiAlBCN ceramics exhibit distinguished oxidation/corrosion resistance after 100 h treatment at 1200℃in a water/oxygen environment,which is attributed to their low corrosive rate constant(0.57 mg/(cm^(2)·h))and oxidative rate constant(3.43 mg^(2)/(cm^(4)·h)).Therefore,polymer-derived SiAlBCN ceramics as sensing materials,which possess outstanding stability and oxidation/corrosion resistance,have great potential for in-situ monitoring of extreme environmental temperatures in the future.展开更多
基金financially supported by Ongoing Research Funding Program(ORF-2025-846),King Saud University,Riyadh,Saudi Arabia.
文摘This research investigates the application of digital images in military contexts by utilizing analytical equations to augment human visual capabilities.A comparable filter is used to improve the visual quality of the photographs by reducing truncations in the existing images.Furthermore,the collected images undergo processing using histogram gradients and a flexible threshold value that may be adjusted in specific situations.Thus,it is possible to reduce the occurrence of overlapping circumstances in collective picture characteristics by substituting grey-scale photos with colorized factors.The proposed method offers additional robust feature representations by imposing a limiting factor to reduce overall scattering values.This is achieved by visualizing a graphical function.Moreover,to derive valuable insights from a series of photos,both the separation and in-version processes are conducted.This involves analyzing comparison results across four different scenarios.The results of the comparative analysis show that the proposed method effectively reduces the difficulties associated with time and space to 1 s and 3%,respectively.In contrast,the existing strategy exhibits higher complexities of 3 s and 9.1%,respectively.
基金supported by the Beihang University’s Young Talents(No.KG16045301)the National Natural Science Foundation(No.21805204)+1 种基金Tianjin Natural Science Foundation(No.19JCQNJC05100)Young Elite Scientists Sponsorship Program by Tianjin(No.TJSQNTJ-2018-17).
文摘Fundamental research and practical applications have examined the manipulation of gas bubbles on open surfaces in lowsurface-tension,high-pressure,and high-acidity,-alkalinity,or-salinity environments.However,to the best of our knowledge,effi cient and general approaches to achieve the smart manipulation of gas bubbles in these harsh environments are limited.Herein,a Fluorinert-infused shape-gradient slippery surface(FSSS)that could eff ectively regulate the behavior of gas bubbles in harsh environments was successfully fabricated.The unique capability of FSSS was mainly attributed to the properties of Fluorinert,which include chemical inertness and incompressibility.The shape-gradient morphology of FSSS could induce asymmetric driving forces to move gas bubbles directionally on open surfaces.Factors infl uencing gas bubble transport on FSSS,such as the apex angle of the slippery surface and the surface tension of the aqueous environment,were carefully investigated,and large apex angles were found to result in large initial transport velocities and short transport distances.Lowering the surface tension of the aqueous environment is unfavorable to bubble transport.Nevertheless,FSSS could transport gas bubbles in aqueous environments with surface tensions as low as 28.5±0.1 mN/m,which is lower than that of many organic solvents(e.g.,formamide,ethylene glycol,and dimethylformamide).In addition,FSSS could also realize the facile manipulation of gas bubbles in various aqueous environments,e.g.,high pressure(~6.8 atm),high acidity(1 mol/L H 2 SO 4),high alkalinity(1 mol/L NaOH),and high salinity(1 mol/L NaCl).The current fi ndings provide a source of knowledge and inspiration for studies on bubble-related interfacial phenomena and contribute to scientifi c and technological developments for controllable bubble manipulation in harsh environments.
基金Project supported by the Tsinghua University Initiative Scientific Research Program(No.20131089351),China
文摘Surface acoustic wave （SAW） sensors and micro-electromechanical system （MEMS） technology provide a promising solution for measurement in harsh environments such as gas turbines. In this paper, a SAW resonator （size： 1107μm× 721 μm） based on the AlN/4H-SiC multilayer structure is designed and simulated. A MEMS-compatible fabrication process is employed to fabricate the resonator. The results show that highly c-axis-oriented AlN thin films deposited on the 4H-SiC substrate are obtained, with that the diffraction peak of AlN is 36.10° and the lowest full width at half maximum （FWHM） value is only 1.19°. The test results of the network analyzer are consistent with the simulation curve, which is very encouraging and indicates that our work is a significant attempt to solve the measurement problems mainly including high temperature stability of sensitive structures and the heat transmission of leads in harsh environments. It is essential to get the best performance of SAW resonator, optimize and characterize the behaviors in high temperatures in future research.
基金supported by the National Natural Science Foundation of China(62401451,62131017)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(GZB20230584)the China Postdoctoral Science Foundation(2024M762579)。
文摘In many industries,there is a growing demand for semiconductor pressure sensors capable of operating in harsh environments with extremely high and low temperatures and high vibrations.Utilizing the piezoresistive effect of heavily doped N-type 4H-SiC,we proposed a family design of eight pressure sensor chip structures featuring different diaphragm shapes of circles and squares,along with different piezoresistor configurations.The 4H-SiC piezoresistive pressure sensor was developed using micro-electromechanical systems(MEMS)technology and encapsulated in a leadless package structure via low-stress connection achieved by glass frit sintering.The 4H-SiC pressure sensor demonstrates impressive performance,exhibiting an accuracy of 0.18%FSO and a temperature tolerance range from−50 to 600°C,with a temperature coefficient of zero output as low as 0.08%/°C at 600°C.Furthermore,the developed sensor shows remarkable stability under conditions of high-temperature vibration coupling.The advancement of this family of 4H-SiC pressure sensors provides a promising solution for pressure measurement in harsh industrial environments.
基金the Natural Science Foundation of Shandong Province,China(No.ZR2021QE043)the National Natural Science Foundation of China(Nos.52101390 and 52331004)the Open Project of Key Lab of Special Functional Materials of Ministry of Education,Henan University(No.KFKT-2022-11).
文摘Triboelectric nanogenerators(TENG)have emerged as a highly promising energy harvesting technology,attracting significant attention in recent years for their broad applications.Gel-based TENGs,with superior stretchability and sensitivity,have been widely reported as wearable sensors.However,the traditional hydrogel-based TENGs suffer from freezing at low temperatures and drying at high temperatures,resulting in malfunctions.In this study,we introduce an anti-freezing eutectogel,which uses a deep eutectic solvent(DES),to improve the stability and electrical conductivity of TENGs in harsh environmental conditions.The eutectogel-based TENG(E-TENG)produces an open-circuit voltage of 776 V,a short-circuit current of 1.54μA,and a maximum peak power of 1.1 mW.Moreover,the E-TENG exhibits exceptional mechanical properties with an elongation at a break of 476%under tension.Importantly,it maintains impressive performances across a wide temperature range from−18 to 60℃,with conductivities of 2.15 S/m at−10℃and 1.75 S/m at−18℃.Based on the excellent weight stability of the E-TENG sensor,motion sensing can be achieved in the air,and even underwater.Finally,the versatility of the E-TENG can serve as a wearable sensor,by integrating it with Bluetooth technology.The self-powered E-TENG can monitor various human motion signals in real-time and send the health signals directly to mobile phones.This research paves a new road for the applications of TENGs in harsh environments,offering wireless flexible sensors with real-time health signal monitoring capabilities.
基金partially supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(No.2018R1A6A1A03025242)by the Korea government(MIST)(RS-2023-00302751,RS-2024-00343686)the Research Grant of Kwangwoon University in 2024。
文摘Recent advancements in passive wireless sensor technology have significantly extended the application scope of sensing,particularly in challenging environments for monitoring industry and healthcare applications.These systems are equipped with battery-free operation,wireless connectivity,and are designed to be both miniaturized and lightweight.Such features enable the safe,real-time monitoring of industrial environments and support high-precision physiological measurements in confined internal body spaces and on wearable epidermal devices.Despite the exploration into diverse application environments,the development of a systematic and comprehensive research framework for system architecture remains elusive,which hampers further optimization of these systems.This review,therefore,begins with an examination of application scenarios,progresses to evaluate current system architectures,and discusses the function of each component—specifically,the passive sensor module,the wireless communication model,and the readout module—within the context of key implementations in target sensing systems.Furthermore,we present case studies that demonstrate the feasibility of proposed classified components for sensing scenarios,derived from this systematic approach.By outlining a research trajectory for the application of passive wireless systems in sensing technologies,this paper aims to establish a foundation for more advanced,user-friendly applications.
文摘Microsystems are increasingly being applied in harsh and/or inaccessible environments,but many markets expect the same level of functionality for long periods of time.Harsh environments cover areas that can be subjected to high temperature,(bio)-chemical and mechanical disturbances,electromagnetic noise,radiation,or high vacuum.In the field of actuators,the devices must maintain stringent accuracy specifications for displacement,force,and response times,among others.These new requirements present additional challenges in the compensation for or elimination of cross-sensitivities.Many state-of-the-art precision devices lose their precision and reliability when exposed to harsh environments.It is also important that advanced sensor and actuator systems maintain maximum autonomy such that the devices can operate independently with low maintenance.The next-generation microsystems will be deployed in remote and/or inaccessible and harsh environments that present many challenges to sensor design,materials,device functionality,and packaging.All of these aspects of integrated sensors and actuator microsystems require a multidisciplinary approach to overcome these challenges.The main areas of importance are in the fields of materials science,micro/nano-fabrication technology,device design,circuitry and systems,(first-level)packaging,and measurement strategy.This study examines the challenges presented by harsh environments and investigates the required approaches.Examples of successful devices are also given.
基金the National Natural Science Foundation of China(NSFC)(Project Nr.:2012YQ25002,11802329).
文摘Advanced sensing techniques are in big demand for applications in hypersonic wind tunnel harsh environments,such as aero(thermo)dynamics measurements,thermal protection of aircraft structures,air-breathing propulsion,light-weighted and highstrength materials,etc.In comparison with traditional electromechanical or electronic sensors,the fiber optic sensors have relatively high potential to work in hypersonic wind tunnel,due to the capability of responding to a wide variety of parameters,high resolution,miniature size,high resistant to electromagnetic and radio frequency interferences,and multiplexing,and so on.This article has classified and summarized the research status and the representative achievement on the fiber optic sensing technologies,giving special attention to the summary of research status on the popular Fabry-Perot interferometric,fiber Bragg gratings and(quasi)distributed fiber optic sensors working in hypersonic wind tunnel environment,and discussed the current problems in special optical fiber sensing technologies.This article would be regarded as reference for the researchers in hypersonic wind tunnel experiment field.
文摘1 The Inuit's remarkable ability to thrive(蓬勃发展)in one of Earth's toughest environments hasn't happened by chance.Their complex system of traditions,passed down through countless generations,represents far more than mere survival strategies-it's a highly developed blueprint for living in harmony with the Arctic's unforgiving landscape.
文摘We present the fabrication and testing of a silicon carbide （SiC） balanced mass doublended tuning fork that survives harsh environments without compromising the device strain sensitivity and resolution bandwidth. The device features a material stack that survives corrosive environments and enables high-temperature operation. To perform hightemperature testing, a specialized setup was constructed that allows the tuning fork to be characterized using traditional silicon electronics. The tuning fork has been operated at 600°C in the presence of dry steam for short durations. This tuning fork has also been tested to 64 000 G using a hard-launch, soft-catch shock implemented with a light gas gun. However, the device still has a strain sensitivity of 66 Hz/μe and strain resolution of 0. 045 μe in a 10 kHz bandwidth. As such, this balanced-mass double-ended tuning fork can be used to create a variety of different sensors including strain gauges, accelerometers, gyroscopes, and pressure transducers. Given the adaptable fabrication process flow, this device could be useful to micro-electro-mechanical systems （MEMS） designers creating sensors for a variety of different applications.
基金financially supported by the National Natural Science Foundation of China(Nos.52275187 and 52202364)Natural Science Foundation of Henan(No.232300421135)+1 种基金Fundamental Research Funds for the Universities of Henan Province(No.NSFRF200101)Henan Postdoctoral Foundation(No.202101035)。
文摘Defects engineering is an effective strategy for manipulating electromagnetic parameters and enhancing electromagnetic wave(EMW)absorption capacity.However,the relationship between them is not clear,especially in solid solution structures.In this work,a series of(Cr_(1-x)V_(x))_(2)AlC MAX phase solid solutions with layered structure were prepared via tuning the ratio of Cr and V to explore their EMW absorption performance.The experimental results indicated that the doping of V atoms at the M-site could effectively regulate its impedance matching and EMW absorption properties by introducing appropriate numbers of defects in the crystal,such as twin boundaries,dislocations and lattice distortions.Among them,if Cr:V=3:1,Cr_(1.5)V_(0.5)AlC,as radar absorption materials,could reach a strong reflection loss of-51.8 dB at the frequency of 12.8 GHz under an ultra-thin thickness of 1.3 mm.The reflection loss value could attain-10 dB in a wide frequency range of 2.7-18 GHz and thickness range of 1-5 mm.In addition,after high temperature and acid-alkali immersion treatment,this sample still had good EMW absorption capability,and the effective absorption bandwidth was enhanced from 2.3 to 2.6 GHz after concentrated acid immersion or 3.1 GHz after concentrated alkali immersion.This work has great reference significance for the research and development of high-performance MAX-based EMW absorption materials in harsh environments.
基金supported by the National Key Research and Development Program of China(No.2022YFB3203900)。
文摘Conformal thin-film sensors enable precise monitoring of the operating conditions of components in extreme environments.However,the development of these sensors encounters major challenges,especially in uniformly applying multiple film layers on complex metallic surfaces and accurately capturing diverse operational parameters.This work reports a multi-sensor design and multi-layer additive manufacturing process targeting spherical metallic substrates.The proposed high-temperature dip-coating and self-leveling fabrication process achieves high-temperature thin-film coatings with excellent uniformity,high-temperature electrical insulation,and adhesion properties.The fabricated Ag/Pt thin film thermocouple arrays and a heat flux sensor exhibit a maximum temperature resistance of up to 960℃,with thermoelectric potential outputs and hightemperature resistance closely mirroring those of wire-based Ag/Pt thermocouples.Harsh environmental testing was conducted using high-power lasers and a flame gun.The results show that the array of thin-film conformal thermocouples more accurately reflected temperature changes at different points on a spherical surface.The heat flux sensors achieve responses within 95 ms and with-stand environments with heat fluxes over 1.2 MW/m^(2).The proposed multi-sensor design and fabrication method offers promising monitoring applications in harsh environments,including aerospace and nuclear power.
文摘The main objective of this paper is to evaluate the seismic response of buildings of typical reinforced concrete frames when concrete starts to deteriorate gradually and to make a comparison between the base shear and the displacement at different stages of earthquake loading. Typical 5, 15, 20 and 30-storey reinforced concrete frames have been designed for seismicity according to the recently adopted seismic code in Abu Dhabi, ACI 318-08/IBC 2009 code. A pushover analysis has been performed to these four buildings by using SAP 2000. Twenty-four models have been created (6 models for each building) by decreasing the concrete strength gradually from 4000 psi (281 kg/cm<sup>2</sup>) to 1500 psi (105 kg/cm<sup>2</sup>). This is to simulate the effect of harsh environment on the strength of concrete in existing buildings.
基金supported by the National Basic Research Program(973 Program)of China(No.2009-CB825103)the National Natural Science Foundation of China(No.40901119)
文摘Arid soils where water and nutrients are scarce occupy over 30% of the Earth's total surface. However, the microbial autotrophy in the harsh environments remains largely unexplored. In this study, the abundance and diversity of autotrophic bacteria were investigated, by quantifying and profiling the large subunit genes of ribulose-1,5-bisphosphate carboxylase/oxygenase(Ru Bis CO) form I(cbb L) responsible for CO2 fixation, in the arid soils under three typical plant types(Haloxylon ammodendron, Cleistogenes chinensis,and Reaumuria soongorica) in Northwest China. The bacterial communities in the soils were also characterized using the 16 S r RNA gene. Abundance of red-like autotrophic bacteria ranged from 3.94 × 105 to 1.51 × 106 copies g-1dry soil and those of green-like autotrophic bacteria ranged from 1.15 × 106 to 2.08 × 106 copies g-1dry soil. Abundance of both red- and green-like autotrophic bacteria did not significantly differ among the soils under different plant types. The autotrophic bacteria identified with the cbb L gene primer were mainly affiliated with Alphaproteobacteria, Betaproteobacteria and an uncultured bacterial group, which were not detected in the 16 S r RNA library. In addition, 25.9% and 8.1% of the 16 S r RNA genes were affiliated with Cyanobacteria in the soils under H. ammodendron and R. soongorica, respectively. However, no Cyanobacteria-affiliated cbb L genes were detected in the same soils. The results suggested that microbial autotrophic CO2 fixation might be significant in the carbon cycling of arid soils, which warrants further exploration.
基金funded by the National Key Research and Development Program subject(Grant No.2018YFC1503903)
文摘Deep penetration into the Earth’s interior and direct monitoring of weak changes in physical fields and their cumulative processes and effects in the deep Earth can enhance the identification of deep Earth targets and deepen the degree of knowledge of the details of the deep Earth structure and deep processes(Moskvitch,2014),which is important for promoting the development of Earth system science.
基金financially supported by the Key Research Program of the Chinese Academy of Sciences(Grant No.KGFZD-125-014)the National Natural Science Foundation of China(Grant No.61273334)State Key Laboratory of Robotics Foundation(Grant No.2017-Z05)
文摘A novel efficient track initiation method is proposed for the harsh underwater target tracking environment(heavy clutter and large measurement errors): track splitting, evaluating, pruning and merging method(TSEPM). Track initiation demands that the method should determine the existence and initial state of a target quickly and correctly.Heavy clutter and large measurement errors certainly pose additional difficulties and challenges, which deteriorate and complicate the track initiation in the harsh underwater target tracking environment. There are three primary shortcomings for the current track initiation methods to initialize a target:(a) they cannot eliminate the turbulences of clutter effectively;(b) there may be a high false alarm probability and low detection probability of a track;(c) they cannot estimate the initial state for a new confirmed track correctly. Based on the multiple hypotheses tracking principle and modified logic-based track initiation method, in order to increase the detection probability of a track,track splitting creates a large number of tracks which include the true track originated from the target. And in order to decrease the false alarm probability, based on the evaluation mechanism, track pruning and track merging are proposed to reduce the false tracks. TSEPM method can deal with the track initiation problems derived from heavy clutter and large measurement errors, determine the target’s existence and estimate its initial state with the least squares method. What’s more, our method is fully automatic and does not require any kind manual input for initializing and tuning any parameter. Simulation results indicate that our new method improves significantly the performance of the track initiation in the harsh underwater target tracking environment.
基金supported by the National Natural Science Foundation of China(Nos.52232005,52172104,and 52293370)Fundamental Research Funds for the Central Universities(China,Nos.3102020QD0411 and D5000220152)+1 种基金Fundamental Research Funds for the Central Universities(No.3102019TS0409)Cre-ative Research Foundation of Science and Technology on Thermo-Structural Composite Materials Laboratory.
文摘Polymer-derived ceramics(PDCs)pyrolyzed at high temperatures are promising electromagnetic wave(EMW)absorption materials for aerodynamically heated parts of aircraft under harsh environments.Nev-ertheless,high-temperature pyrolysis results in a significant increase of electrical and dielectric proper-ties of the ceramics,causing extensive reflection of EMW.To address this challenge,boron nitride-coated carbon nanotubes(BN@CNTs)were fabricated and introduced into polymer-derived SiC(PDC-SiC)by py-rolyzing its precursor higher than 1200℃to form SiC-BN@CNT ceramic composites.The fabricated com-posites with 3 wt.%BN@CNTs pyrolyzed at 1200℃have an effective absorption bandwidth(EAB)of 4.2 GHz(8.2-12.4 GHz)at a thickness of 3.4 mm and the minimum reflection loss(RL min)of-57.20 dB.The ultra-broad EAB of 12.62 GHz(5.38-18 GHz)is obtained by simulation through periodic structure design-ing.The RL of the metamaterials was also measured using an arch testing method at a frequency range of 2-18 GHz and an EAB of 11.52 GHz(6.48-18 GHz)is obtained.The excellent absorption is attributed to the BN layer that limits the electrical conduction of the ceramic composites while retaining the high loss of CNTs.The introduction of BN@CNTs causes the refinement of SiC grains,which provides plenty of interfaces and enhances the interface polarization loss.This work successfully solves the problem that PDCs pyrolyzed at elevated temperatures cannot be used as EMW absorption materials by applying BN coating on CNTs served as absorbers for PDC-SiC.The results of this work greatly broaden the application scope of the PDC systems for EMW absorption.
基金supported by the National Key R&D Pro-gram of China(Grant No.2023YFE0114600)The National Natural Science Foundation of China(NSFC)(Grant No.52477029)Joint Laboratory of China-Morocco Green Energy and Advanced Materials,The Youth Innovation Team of Shaanxi Universities and The Xi’an City Science and Technology Project(No.23GXFW0070)。
文摘Floating photovoltaic(FPV)technology is emerging as a highly promising approach to accelerate decarbonization of the global economy,due to its higher power generation efficiency and lower land occupation.With the rapid development of FPV technology,the mechanical performance degradation of key components caused by the harsh marine environment has become a pressing issue,as it significantly contributes to failure behavior observed in FPV systems.A comprehensive compilation of the mechanical performance of key components in FPV systems is also currently unavailable.Here,the mechanical behavior of each structural component in FPV systems under harsh marine environments is systematically reviewed.It further emphasizes the synergistic effects of mechanical performance degradation among different components on the overall system.The drop-off rate(v)of normalized elongation at break(EAB)of polymer under the synergistic effect of various environmental factors increases from 7.5×10^(−4)h^(−1)to 21.8×10^(−4)h^(−1)compared with the single environmental stress.Moreover,the development of novel materials and innovative mechanical structures applied in FPV systems to enhance mechanical performance is discussed.The novel flexible PV modules applied in FPV systems minimize the loads acting on the mooring lines by 80%and increase power generation by 5%.Notably,this paper provides a theoretical foundation for developing standards of FPV systems,especially the establishment of standards related to the synergistic effects of the mechanical performance degradation of different key components on FPV systems.
基金supported by the National Natural Sci-ence Foundation of China(No.52003074,52125205,U20A20166,52192614,52003073,and 62174049)the Project funded by China Postdoctoral Science Foundation(No.2020M680097)+5 种基金the Postdoctoral Fellowship Program of CPSF(No.GZC20230681)the Natural Science Foundation of Henan Province(No.202300410058)the National Sci-ence Fund for Excellent Young Scholars of Henan Province(No.222300420033)National key R&D program of China(2021YFB3200302 and 2021YFB3200304),Natural Science Foundation of BeijingMunicipality(Z180011 and 2222088)Shenzhen Science and Technology Program(grant number KQTD20170810105439418)the Fundamental Research Funds for the Central Universities.
文摘The triboelectric nanogenerator(TENG)offers a novel approach to harness mechanical energy continuously and sustainably.It has emerged as a leading technology for converting mechanical energy into electricity.The demand for self-powered wearable microelectronics and energy generation in extreme conditions underscores the need for efficient high-temperature operatable TENGs(HTO-TENGs).However,the operating environment temperature not only affects the storage and dissipation of electrons during triboelectrification,leading to decreased output performance of TENG and instability at high temperatures,but also damage to the mechanical stability and effective defects in most tribomaterials,resulting in a further reduction in TENG’s effective output power.Moreover,the unstable material properties of the triboelectric layer at high temperatures also restrict the use of the TENG in harsh environments.Therefore,it is imperative to consider the structural durability and electrical output stability of TENG when applying it in challenging working environments.This review aims to bridge this gap by providing a comprehensive overview of the current state and research advancements in HTO-TENG for the first time.Finally,this review presents insights into future research prospects and proposes design strategies to facilitate the rapid development of the field.
基金the National Key R&D Program of China(No.2021YFB3200500)the National Natural Science Foundation of China(Nos.52072344 and U1904180)+1 种基金the Excellent Young Scientists Fund of Henan Province(No.202300410369)the Henan Province University Innovation Talents Support Program(No.21HASTIT001).
文摘In situ temperature monitoring has become extremely imperative in high-temperature harsh environments and polymer-derived ceramics(PDCs)as sensing materials have attracted great attention.However,the stability and oxidation/corrosion resistance of PDCs cannot be simultaneously achieved at the moment,limiting their practical application.Herein,polymer-derived SiAlBCN ceramics were synthesized via polymer conversion method under different pyrolysis temperatures.Their microstructure evolution,high temperature sensing properties,and stability were investigated in detail.The results show that the amorphous SiAlBCN phase grows more orderly and the size of the free carbon phase enlarges with the increasing temperature.The defect concentration displays a decreasing tendency.Concurrently,the SiAlBCN ceramics as sensing materials exhibit a good temperature-resistance property from roo temperature to 1100℃.The fabricated SiAlBCN temperature sensor possesses excellent stability,repeatability,and accuracy.Moreover,SiAlBCN ceramics exhibit distinguished oxidation/corrosion resistance after 100 h treatment at 1200℃in a water/oxygen environment,which is attributed to their low corrosive rate constant(0.57 mg/(cm^(2)·h))and oxidative rate constant(3.43 mg^(2)/(cm^(4)·h)).Therefore,polymer-derived SiAlBCN ceramics as sensing materials,which possess outstanding stability and oxidation/corrosion resistance,have great potential for in-situ monitoring of extreme environmental temperatures in the future.
