Mixed halide perovskites exhibit great potential as materials for the future generation of photovoltaic devices.Yet,their reaction to moisture remains uncertain,necessitating further exploration.While prolonged exposu...Mixed halide perovskites exhibit great potential as materials for the future generation of photovoltaic devices.Yet,their reaction to moisture remains uncertain,necessitating further exploration.While prolonged exposure to moisture can lead to degradation,it can also passivate traps at an optimal moisture level.Here,we use scanning probe microscopy to perform nanoscale moisture-dependent photovoltaic characterizations of open and compressed grain boundary(GB)structures of wide bandgap(FAPbI_(3))_(0.3)(FAPbBr_(3))_(0.7) perovskites.The investigation reveals a decrease in the potential barrier at compact GBs with increasing moisture levels,contrasting with the behavior observed in open GBs.Moreover,the photocurrent distribution over both samples proportionally increases when relative humidity(RH)is raised from 10%to 60%.Notably,following a 24-h exposure at RH 60%,the compact-GB sample demonstrates:i)a reduction in the density of charged trap states at GBs,ii)higher photocurrent,accompanied by a noticeable decrease in current hysteresis compared to the open GB sample,and iii)further enhancement in device efficiency and crystallinity compared to devices with open GBs.These findings suggest that optimizing humidity conditions in engineering the GB chemistry can enhance the optoelectrical properties of GBs,ultimately leading to improved device performance.展开更多
The high efficiency particulate air filter(HEPA)in exhaust system of high-level biosafety laboratory must be disinfected to kill harmful microorganisms before being replaced or tested.In-situ fumigation by vaporized h...The high efficiency particulate air filter(HEPA)in exhaust system of high-level biosafety laboratory must be disinfected to kill harmful microorganisms before being replaced or tested.In-situ fumigation by vaporized hydrogen peroxide(VHP)is the most commonly used disinfection method for HEPA unit.The disinfection effect of HEPA unit is affected by the internal environment,but the influence of initial internal environment on VHP penetration during the fumigation process is still rarely studied.In this paper,a numerical model was established based on a physical HEPA box unit and field measurement.According to the simulated VHP flow field during in-situ fumigation process,the influence of initial internal temperature and relative humidity on the VHP penetration effect in HEPA was discussed with the indicators of penetration rate and velocity distribution.The results showed that the VHP concentration in the upstream section of HEPA was relatively uniform,while the maximum and minimum concentrations in the downstream section showed great difference and located at the top and bottom,respectively.The distributions of VHP penetration and upstream velocity were both vertically uneven.The VHP penetration rates in the middle of HEPA remained around 73%.The initial temperature of 32℃or 36℃,or the initial relative humidity of 18%were the suitable initial internal environment for HEPA in-situ fumigation,which could keep the VHP penetration rates of the upper and lower parts of HEPA at about 76%and 61%,respectively.In the suitable initial environment,the penetration and disinfection effect could be promoted by appropriately extending the rapid injection duration.This study provides a reference for optimizing the initial environment setting of HEPA in-situ fumigation.展开更多
The growing demand for personalized health care,smart wearables,and advanced environmental monitoring has spurred the development of multifunctional materials that combine flexibility,environmental adaptability,and di...The growing demand for personalized health care,smart wearables,and advanced environmental monitoring has spurred the development of multifunctional materials that combine flexibility,environmental adaptability,and diverse functionalities.However,conventional materials often failed to integrate these attributes simultaneously,hindering their applicability in next-generation technologies.Here,we present an organic-inorganic hybrid crystalline material with a unique sandwich-like architecture,in which a flexible organic crystal core is encased by reduced graphene oxide(rGO)and thermoplastic polyurethane(TPU).This strategic integration endows the material with fluorescence,cryogenic flexibility,and electrical conductivity,while also enabling dual sensing and actuation capabilities.The rGO layer facilitates real-time humidity(25-90%RH)and temperature(25-180℃)sensing through environmental interactions,whereas the differential thermal expansion between TPU and the flexible crystal core drives efficient photothermal actuation at-150℃ for advanced thermal regulation.The hybrid material exhibits stable performance under extreme conditions,making it a promising candidate for biomedical monitoring,flexible electronics,and energy applications.This work establishes hybrid crystalline materials as versatile and scalable platforms for addressing complex technological demands,paving the way for their application in next-generation multifunctional devices.展开更多
The field of disease smelling diagnosis has experienced a major breakthrough with the development of the electronic nose(E-nose)that utilizes thiol-capped gold nanoparticles(GNPs).This study focuses on overcoming the ...The field of disease smelling diagnosis has experienced a major breakthrough with the development of the electronic nose(E-nose)that utilizes thiol-capped gold nanoparticles(GNPs).This study focuses on overcoming the challenges of sensors to detect VOCs stably confounding with interferents of humidity and pressure,and clarifying their essential mechanism.An innovative and straightforward method for synthesizing GNPs and modifying their surface has been developed.This unique approach deviates from the conventional Brust method by completely removing any traces of tetraoctylammonium bromide(TOAB),ensuring reproducibility and simplicity of use.This modification enhances the sensor's responsiveness to both polar and non-polar VOCs,as well as strengthen selectivity and anti-interferant capabilities.The mechanism of generating sensing cross-talk from TOAB residue is proposed through rigorous sensing experiments,X-ray photoelectron spectroscopy(XPS)results,and theoretical analysis.Thus,this study enhances the responsiveness of the sensor to both polar and non-polar VOCs,while also strengthening its selectivity and anti-interferent capabilities.This could potentially revolutionize the practical applications of E-nose in smelling diagnosis.展开更多
Relative humidity(RH)plays a pivotal role in regulating plant transpiration by modulating stomatal conductance().Accurate modeling under varying RH conditions is essential for predicting plant water use and gas exchan...Relative humidity(RH)plays a pivotal role in regulating plant transpiration by modulating stomatal conductance().Accurate modeling under varying RH conditions is essential for predicting plant water use and gas exchange,with important implications for both agricultural management and bionic applications.In this study,field experiments were conducted to measure in plants exposed to moderate-and high-RH environments.The results demonstrated that is greater and transpiration rates are lower in high-RH environments than in moderate-RH environments.The response functions of stomatal conductance to environmental factors were further developed via a boundary line technique.These functions elucidate how stomatal conductance is correlated with environmental conditions.Specifically,stomatal conductance reaches saturation at a photosynthetically active radiation(PAR)of approximately 300 and 500μmol·m^(−2)·s^(−1) in both high-and moderate-RH environments.Furthermore,the vapor pressure deficit(VPD)threshold triggering stomatal closure was shifted by ambient RH,occurring at approximately 1000 Pa under high RH and 2000 Pa under moderate RH.This RH-dependent adjustment highlights the indirect yet critical role of RH in modulating stomatal sensitivity to atmospheric dryness.On the basis of the established response functions,stomatal conductance models tailored for high-and moderate-RH environments were constructed by extending the Jarvis empirical framework.These models offer improved predictive capacity for simulating plant physiological responses under diverse humidity conditions and provide new insights into the stomatal regulation of plants in natural field settings.展开更多
To facilitate real-time monitoring and recording of humidity in the environment and to satisfy the requirement for strain performance in certain applications(such as wearable devices),this paper proposes an in-situ me...To facilitate real-time monitoring and recording of humidity in the environment and to satisfy the requirement for strain performance in certain applications(such as wearable devices),this paper proposes an in-situ method for synthesising Au nanoparticles on ZIF-67.In this study,an Au@ZIF-67 composite humidity-sensitive material was combined with flexible polyethylene terephthalate interdigitated electrodes to create an Au@ZIF-67 flexible humidity sensor.The prepared samples were characterised using X-ray diffraction,X-ray photoelectron spectroscopy,and transmission electron microscopy.The humidity-sensitive properties of the sensor were investigated,and its monitoring capabilities in applications involving respiration,gestures,skin,and baby diapers were tested.The experimental results indicate that compared with a pure ZIF-67 humidity sensor,the Au@ZIF-67(0.1Au@Z)flexible humidity sensor exhibits a 158.07%decrease in baseline resistance and a 51.66%increase in sensitivity to 95%relative humidity,and the hysteresis,response time,and recovery time are significantly reduced.Furthermore,the sensor exhibits excellent characteristics such as high resolution,repeatability,and stability.The obtained results regarding the material properties,humidity sensitivity,and practical application of non-contact humidity monitoring demonstrate that the prepared sensors exhibit excellent and comprehensive performance,indicating their broad prospects in wearable medical devices,wireless Internet of Things,humidity detection in complex environments,and intelligent integrated systems.展开更多
The factors controlling dust activity and humidity in Central Asia and their relationships remain controversial,partly due to a lack of high-resolution geological records for the mid-to-late last glaciation.In this st...The factors controlling dust activity and humidity in Central Asia and their relationships remain controversial,partly due to a lack of high-resolution geological records for the mid-to-late last glaciation.In this study,we established an optically stimulated luminescence chronology for the QSHA profile in the Yili Basin,a region influenced by westerlies.Grain size and trace element data were used as paleoclimatic indicators.We investigated the relationships among Central Asian dust activity,humidity,and westerlies strength on orbital to millennial scale from 37.4 ka to 11.6 ka.Our study reveals that,on orbital timescales,humidity is positively correlated with westerlies strength which controlled by precession.Dust activity is controlled by Siberian High which was regulated by Northern Hemisphere high-latitude temperature.Their responses to low-latitude and high-latitude forcing mechanisms respectively and present an opposite relationship.On millennial timescales,humidity and westerlies strength are positively correlated.During Marine Isotope Stage(MIS)2,humidity and dust activity show synchronous fluctuations,while during MIS 3,they exhibit an inverse relationship.Westerlies strength regulated humidity,which subsequently controlled glacial activity in the Tianshan Mountains,influencing dust activity in Central Asia.Additionally,the QSHA profile recorded seven Dansgaard-Oeschger(D-O)events on millennial timescales,indicating a potential link between Central Asian dust activity and high-latitude temperature variations in the Northern Hemisphere.Our findings provide new insights into dust and humidity interaction during the last glaciation periods in Central Asia and contribute to understanding global dust and hydrological cycles.展开更多
A high humidity-resistant,dual mechanical responsive,and reversible mechanochromic wrinkling system based on a VHB 4910-polydimethylsiloxane(PDMS)substrate with a thin film consisting of 90 wt%poly(vinyl butyral)(PVB)...A high humidity-resistant,dual mechanical responsive,and reversible mechanochromic wrinkling system based on a VHB 4910-polydimethylsiloxane(PDMS)substrate with a thin film consisting of 90 wt%poly(vinyl butyral)(PVB)and 10 wt%hydroxypropyl cellulose(HPC)has been reported.The wrinkling system exhibited significant optical tuning from transparent to opaque states with 50%changes in transmittance,which was achieved through the dual mechanical modes of pre-stretching and releasing processes or bending.Upon exposure to ethanol vapor or a re-flattening process,wrinkles can be erased,yielding a transparent state.Consequently,the wrinkling system could be reversibly switched between transparency and opacity for 1000 cycles with marginal changes in the optical performance.Owing to the insolubility of PVB in water,the wrinkling patterns exhibited excellent durability in high-humidity environments(relative humidity(RH)=99%).Furthermore,the smart encryption device is also demonstrated via mechano-controlled surface topography by patterning the wrinkling system,suggesting potential applications of the designed structure in smart windows,anti-counterfeiting,dynamic display,optical information encryption,and rewritable surfaces.展开更多
Monolithic catalysts with excellent O_(3)catalytic decomposition performance were prepared by in situ loading of Co-doped KMn_(8)O_(16)on the surface of nickel foam.The triple-layer structure with Co-doped KMn_(8)O_(1...Monolithic catalysts with excellent O_(3)catalytic decomposition performance were prepared by in situ loading of Co-doped KMn_(8)O_(16)on the surface of nickel foam.The triple-layer structure with Co-doped KMn_(8)O_(16)/Ni6MnO_(8)/Ni foam was grown spontaneously on the surface of nickel foam by tuning the molar ratio of KMnO_(4)to Co(NO_(3))_(2)·6H_(2)O precursors.Importantly,the formed Ni6MnO_(8)structure between KMn_(8)O_(16)and nickel foam during in situ synthesis process effectively protected nickel foam from further etching,which significantly enhanced the reaction stability of catalyst.The optimum amount of Co doping in KMn_(8)O_(16)was available when the molar ratio of Mn to Co species in the precursor solution was 2:1.And the Mn2Co1 catalyst had abundant oxygen vacancies and excellent hydrophobicity,thus creating outstanding O_(3)decomposition activity.The O_(3)conversion under dry conditions and relative humidity of 65%,90%over a period of 5 hr was 100%,94%and 80%with the space velocity of 28,000 hr^(−1),respectively.The in situ constructed Co-doped KMn_(8)O_(16)/Ni foam catalyst showed the advantages of low price and gradual applicability of the preparation process,which provided an opportunity for the design of monolithic catalyst for O_(3)catalytic decomposition.展开更多
High-efficiency formamidinium lead iodide(FAPbI3)-based perovskite solar cells(PSCs)typically involve annealing in humid air during the fabrication process of perovskite films.However,the combined effects of humidity ...High-efficiency formamidinium lead iodide(FAPbI3)-based perovskite solar cells(PSCs)typically involve annealing in humid air during the fabrication process of perovskite films.However,the combined effects of humidity and relatively high temperature often result in the uncontrollable formation of a detrimental PbI_(2)phase in the perovskite films.As a result,the annealing process of perovskite films is highly sensitive to the relative humidity fluctuations of the environment.Under solar illumination,the undesired PbI_(2)tends to decompose,accelerating the degradation of perovskite materials and severely compromising the light stability of PSCs.This issue is particularly critical for the buried interface and bulk of the perovskite films,as these regions absorb the majority of the incident light.Pre-treatment and posttreatment strategies are generally confined to address the PbI_(2)issues at the buried interface and on the surface of the perovskite films,respectively.However,effectively addressing the effects of excess PbI_(2)at buried interface and grain boundaries within bulk in a single step remains challenging.In this study,we propose an intermediate-treatment strategy using phthalylglycyl chloride(PTC),which involves treating the wet films with PTC prior to annealing during the formation process of the perovskite films.This approach protects the grain boundaries of polycrystalline perovskite films in advance,effectively preventing moisture-induced degradation of the perovskites and thus significantly broadening the relative humidity window of annealing process.Our results demonstrate that this strategy can successfully suppress the formation of PbI_(2)at the grain boundaries and buried interface of perovskite films,thereby eliminating the PbI_(2)-induced degradation pathways.Our strategy significantly reduces the sensitivity to humidity fluctuations during annealing for fabricating stable PSCs,ensuring more consistent fabrication of stable PSCs.Consequently,the resulting PSCs achieve a champion power conversion efficiency of 26.1% and demonstrate excellent light stability.展开更多
Proton exchange membrane fuel cell(PEMFC)is a promising clean energy source,but its performance and stability are vulnerable to the negative effects of humidity conditions.The gas diffusion substrate(GDS)plays a pivot...Proton exchange membrane fuel cell(PEMFC)is a promising clean energy source,but its performance and stability are vulnerable to the negative effects of humidity conditions.The gas diffusion substrate(GDS)plays a pivotal role in regulating the moisture and gas transport.The single pore structure of traditionally designed GDS often leads to the pathway competition between moisture and gas,which effects the efficiency of fuel cells.In this study,we report on a hierarchical fibrous paper with tunable hierarchical pores for a sustainable GDS.This design offers gas permeability under wet conditions,by separating the gas pathway from the moisture pathway,thus mitigating their pathway competition.In addition,this paper forms a multi-scale scaffold that absorbs moisture under high humidity conditions and releases it under dry conditions.It is allowed to maintain an optimal internal humidity and further enhances the humidity adaptability.Furthermore,the carbon footprint is only 15.97%,significantly lower than commercial alternatives.This feature makes it a sustainable solution to stabilize PEMFCs under diverse humidity conditions.展开更多
Halide solid-state electrolytes(HSSEs)with excellent ionic conductivity and high voltage stability are promising for all-solid-state Li-ion batteries(ASSLBs).However,they suffer from poor processability,mechanical dur...Halide solid-state electrolytes(HSSEs)with excellent ionic conductivity and high voltage stability are promising for all-solid-state Li-ion batteries(ASSLBs).However,they suffer from poor processability,mechanical durability and humidity stability,hindering their large-scale applications.Here,we introduce a dry-processing fibrillation strategy using hydrophobic polytetrafluoroethylene(PTFE)binder to encapsulate Li_(3)InCl_(6)(LIC)particles(the most representative HSSE).By manipulating the fibrillating process,only 0.5 wt%PTFE is sufficient to prepare free-standing LIC-PTFE(LIC-P)HSSEs.Additionally,LIC-P demonstrates excellent mechanical durability and humidity resistance.They can maintain their shapes after being exposed to humid atmosphere for 30 min,meanwhile still exhibit high ionic conductivity of>0.2m S/cm at 25℃.Consequently,the LIC-P-based ASSLBs deliver a high specific capacity of 126.6 m Ah/g at0.1 C and long cyclability of 200 cycles at 0.2 C.More importantly,the ASSLBs using moisture-exposed LIC-P can still operate properly by exhibiting a high capacity-retention of 87.7%after 100 cycles under0.2 C.Furthermore,for the first time,we unravel the LIC interfacial morphology evolution upon cycling because the good mechanical durability enables a facile separation of LIC-P from ASSLBs after testing.展开更多
This paper presents a multi-scale experimental investigation of the weathering degradation of red mudstone.Natural rocks were extracted from the surface ground to 120 m,inwhich three sets of samples were selected to c...This paper presents a multi-scale experimental investigation of the weathering degradation of red mudstone.Natural rocks were extracted from the surface ground to 120 m,inwhich three sets of samples were selected to consider the different initial rock fabrics.The long-term relative humidity(RH)cycles under two amplitudes were imposed on red mudstone to simulate the weathering process.After RH cycles,a series of uniaxial compression tests,Brazilian splitting tests and bender-extender element tests were carried out to examine the reduction in strength and stiffness.The objective of this study is to develop an extended stress-volume framework characterizing the degradation of natural red mudstone both at microscale and macroscale.Accompanied by the irreversible swelling of the rock specimen is the progressive degradation of strength,stiffness and Poisson's ratio.A unified exponential degradation model in terms of the irreversible volumetric strain was thus proposed to capture such a degradation pattern.The effect of the initial rock fabric was evident.The highest degradation rate and potential were identified in slightly weathered specimens.Significant slaking of aggregates and crack propagation were confirmed by scanning electron microscope(SEM)micrographs,which were considered as the main consequence of structure damage leading to degradation of mechanical properties.The structure damage during RH cycles denoted the hysteresis nature in the response to the cycling hydraulic reaction,in turn causing the increase in volumetric strain.Thus,the stress-volume relation rather than the suction relation was found in more reasonable agreement with the experimental results.展开更多
The large dynamic range and high performance of temperature and humidity profile lidar made it a popular tool for monitoring the atmospheric environment.In this study,we carried out an accurate analysis of the key com...The large dynamic range and high performance of temperature and humidity profile lidar made it a popular tool for monitoring the atmospheric environment.In this study,we carried out an accurate analysis of the key components of the lidar system,including lasers,the emitting and receiving light paths,and photodetectors.We combined the validation of simulations with experimental testing,and then the applicability indicators and necessary conditions in accordance were suggested.For the frequency stability of the laser,when the wavelength shift is less than 0.15%,the measurement accuracy of the system can be guaranteed to be less than 5%.The degree of near-field signal distortion will be significantly impacted by the size of the geometric factor’s transition zone.The introduced measurement error is less than 2%when the deviation angle of the emission axis is less than 0.1 mrad.It has been tested that selecting a low-sensitivity detector can help to improve the sensitivity of temperature detection since this channel is sensitive to the detector’s nonlinearity.To enhance lidar’s detection capabilities and direct the lidar system design process,it is beneficial to analyze the precision of the key components.展开更多
Rare earth(RE)doped ferrites with the chemical formula Cu_(0.3)Zn_(0.3)Mg_(0.4)T_(x)Fe_(2-x)O_(4)(x=0,0.1;T=La,Ce,Sr)were synthesized by chemical co-precipitation method.The structural,optical,electrical and humidity ...Rare earth(RE)doped ferrites with the chemical formula Cu_(0.3)Zn_(0.3)Mg_(0.4)T_(x)Fe_(2-x)O_(4)(x=0,0.1;T=La,Ce,Sr)were synthesized by chemical co-precipitation method.The structural,optical,electrical and humidity sensing properties of Cu-Mg-Zn ferrites with rare earth element doping were investigated.Single-phase cubic spinel structure was confirmed via X-ray diffraction(XRD),and the crystal size ranges fro m 22.12 to 63.17 nm according to the Scherrer formula and from 25.66 to 67.46 nm according to the Williamson-Hall method.Po rous structure and elemental characterization of the samples were investigated by scanning electron microscopy(SEM).The optic band gap varies between 2.21 and 2.49 eV.Electrical measurements were conducted in the frequency range of 1 Hz-20 MHz and temperature range of 25-400℃.It has been determined that the dielectric results are consistent with the Maxwell-Wagner method and exhibit a non-Debye relaxation model,as observed from the Nyquist plots.At a minimum frequency value of 1 Hz,the dielectric constants for pure,Ce,Sr,and La samples are 9×10^(4),5×10^(4),1×10^(8),and 2×10^(5) at 25℃,and 1.85×10^(8),1.34×10^(8),1.15×10^(10),and 4.4×10^(8)at 400℃.In the same order,for the maximum frequency value of 20 MHz,the dielectric constants at 25℃are 169,166,3799,and 60,while at 400℃they are 734,624,12108,and 774.The La doped sample's low dielectric loss makes it suitable for high-frequency applications.Humidity measurements were performed at room temperature and in the 5%-95%relative humidity range.The humidity properties of the samples were investigated through humidity mapping,sensitivity,hysteresis,and long-term stability tests.Compared to other samples,the results indicate that Ce exhibits better humidity performance with 99%sensitivity and the highest repeatability(91.2%).These results show that Ce-doped ferrite can be used as a low-cost,high-performance humidity sensor.展开更多
This paper presents a thermophysical study approach for a pure environmental control system(ECS),incorporating the geometric dimensions of heat exchangers,ram air duct,and air cycle machine(ACM)blades of the Sabreline...This paper presents a thermophysical study approach for a pure environmental control system(ECS),incorporating the geometric dimensions of heat exchangers,ram air duct,and air cycle machine(ACM)blades of the Sabreliner’s environmental control system.Real flight scenarios are simulated by considering flight input variables such as altitude,aircraft speed,compression ratio of the air cycle machine,and the mass flow rate of bleed air.The study evaluates the coefficient of performance(COP)of the environmental control system,the heat exchanger efficiencies,and the work distribution of the air cycle machine based on five flight scenarios,with a particular focus on considering the effects of humidity on environmental control system performance.The results demonstrate that at cruising altitude(11,000 m),air humidity conditions allow an increase in the COP of around 9.28%compared to dry conditions.Conversely,on land,humidity conditions reduce the performance by 4.26%compared to dry conditions.It was also found that the effects of humidity at high aircraft speeds become negligible.In general terms,the humidity conditions in the air proved to have positive effects on the environmental control system’s performance but negative effects on the heat exchanger efficiencies,reducing them by 0.22%.Additionally,land conditions reflect significant improvements in performance when the compression ratio of the air cycle machine is varied.Furthermore,in the work distribution of the air cycle machine,humidity conditions were demonstrated to consume 2.91%less work fromthe turbine compared to dry conditions.展开更多
Based on ground observation data of relative humidity,the prediction performance of STNF and MIFS in each competition area during February 13-26,2024 was tested and evaluated by using two intelligent forecasting metho...Based on ground observation data of relative humidity,the prediction performance of STNF and MIFS in each competition area during February 13-26,2024 was tested and evaluated by using two intelligent forecasting methods(STNF and MIFS).The results show that STNF had better performance in forecasting relative humidity in high-altitude areas,and was suitable for fine forecasting under complex terrain.MIFS improved the short-term forecast of some low-altitude stations,but the long-term reliability was insufficient.STNF method performed better than MIFS during 0-24 h.As the prediction time extended to 24-72 h,the errors of both methods showed a systematic increase trend.STNF had higher precision,lower root mean square error and smaller mean error in most regions under the background of most weather systems,showing its superiority as a forecasting method of relative humidity.However,the precision of MIFS was slightly higher than that of STNF in Liangcheng without system background,revealing that MIFS may also be an effective option in some specific conditions.展开更多
As an indispensable part of modern buildings,centralized central air conditioning systems play an important role in maintaining the comfort and air quality of the indoor environment.However,with the increasing energy ...As an indispensable part of modern buildings,centralized central air conditioning systems play an important role in maintaining the comfort and air quality of the indoor environment.However,with the increasing energy consumption,how to improve the energy efficiency ratio of air conditioning systems and reduce energy consumption has become an important issue in research and practice.The purpose of this paper is to discuss the impact of humidity control strategies on energy saving in centralized central air conditioning systems,with a view to providing a theoretical basis and practical guidance for realizing building energy efficiency.展开更多
Under the condition of high temperature, the effects of five cover patterns （clean tillage, film mulching, weed covering, branches and leaves covering and growing grass covering） on soil properties in young Phoebe b...Under the condition of high temperature, the effects of five cover patterns （clean tillage, film mulching, weed covering, branches and leaves covering and growing grass covering） on soil properties in young Phoebe boumei forest were in- vestigated. The results showed that the five cover patterns all showed significant ef- fects on soil properties in young Phoebe bournei forest under the condition of high temperature. Land cover increased land temperature in Phoebe boumei forest. Un- der the film mulching, the land temperature was increased most rapidly with the largest increment. However, weed covering, branches and leaves covering and growing grass covering decreased land temperature. Among them, growing grass covering showed the best cooling effect. The film mulching, weed covering, branch- es and leaves covering and growing grass covering all increased land humidity. The film mulching showed the best moisture-preserving effect in the early period, but in the late period, the humidity in the film mulching treatment group was lower than that in the clean tillage treatment group. Among the five mulching patterns, moisture loss in the film mulching treatment group was slowest and least, followed by those in the weed covering and branches and leaves covering treatment groups, and moisture loss in the growing grass covering treatment group was fastest and most.展开更多
In order to analyze the ventilation and cooling performance of single-tunnel plastic greenhouse in Yangtze-Huai region, the effects of two different ventilation modes （side window, side window＋roof window） on the t...In order to analyze the ventilation and cooling performance of single-tunnel plastic greenhouse in Yangtze-Huai region, the effects of two different ventilation modes （side window, side window＋roof window） on the temperature and humidity of plastic greenhouse were studied. The results showed that the ventilation mode of opening side window and roof window could effectively reduce the temperature and humidity at the plant canopy height, which was conducive to the growth of plant in greenhouse.展开更多
基金support from the Australian Research Council through Discovery Grants and the ARC Centre of Excellence in Future Low-Energy Electronics Technologies(FLEET)supported by the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(NRF-2021K1A4A7A03093851)+1 种基金J.S.Y.acknowledges the Royal Society research grant(RGS/R1/221369)the support by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MEST)(RS-2023-00257494 and 2022H1D3A2A01082324).
文摘Mixed halide perovskites exhibit great potential as materials for the future generation of photovoltaic devices.Yet,their reaction to moisture remains uncertain,necessitating further exploration.While prolonged exposure to moisture can lead to degradation,it can also passivate traps at an optimal moisture level.Here,we use scanning probe microscopy to perform nanoscale moisture-dependent photovoltaic characterizations of open and compressed grain boundary(GB)structures of wide bandgap(FAPbI_(3))_(0.3)(FAPbBr_(3))_(0.7) perovskites.The investigation reveals a decrease in the potential barrier at compact GBs with increasing moisture levels,contrasting with the behavior observed in open GBs.Moreover,the photocurrent distribution over both samples proportionally increases when relative humidity(RH)is raised from 10%to 60%.Notably,following a 24-h exposure at RH 60%,the compact-GB sample demonstrates:i)a reduction in the density of charged trap states at GBs,ii)higher photocurrent,accompanied by a noticeable decrease in current hysteresis compared to the open GB sample,and iii)further enhancement in device efficiency and crystallinity compared to devices with open GBs.These findings suggest that optimizing humidity conditions in engineering the GB chemistry can enhance the optoelectrical properties of GBs,ultimately leading to improved device performance.
基金supported by the Natural Science Foundation of Hebei Province(Project no.E2023202232)Science and Technology Research Project for Colleges and Universities in Hebei Province(Project no.CXY2024026).
文摘The high efficiency particulate air filter(HEPA)in exhaust system of high-level biosafety laboratory must be disinfected to kill harmful microorganisms before being replaced or tested.In-situ fumigation by vaporized hydrogen peroxide(VHP)is the most commonly used disinfection method for HEPA unit.The disinfection effect of HEPA unit is affected by the internal environment,but the influence of initial internal environment on VHP penetration during the fumigation process is still rarely studied.In this paper,a numerical model was established based on a physical HEPA box unit and field measurement.According to the simulated VHP flow field during in-situ fumigation process,the influence of initial internal temperature and relative humidity on the VHP penetration effect in HEPA was discussed with the indicators of penetration rate and velocity distribution.The results showed that the VHP concentration in the upstream section of HEPA was relatively uniform,while the maximum and minimum concentrations in the downstream section showed great difference and located at the top and bottom,respectively.The distributions of VHP penetration and upstream velocity were both vertically uneven.The VHP penetration rates in the middle of HEPA remained around 73%.The initial temperature of 32℃or 36℃,or the initial relative humidity of 18%were the suitable initial internal environment for HEPA in-situ fumigation,which could keep the VHP penetration rates of the upper and lower parts of HEPA at about 76%and 61%,respectively.In the suitable initial environment,the penetration and disinfection effect could be promoted by appropriately extending the rapid injection duration.This study provides a reference for optimizing the initial environment setting of HEPA in-situ fumigation.
基金support from the National Natural Science Foundation of China(52373181 and 52173164)the Natural Science Foundation of Jilin Province(20250102120JC and 20230101038JC)+1 种基金the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(GZB20240259)the Project funded by China Postdoctoral Science Foundation(2024M761121 and 2025T180139).
文摘The growing demand for personalized health care,smart wearables,and advanced environmental monitoring has spurred the development of multifunctional materials that combine flexibility,environmental adaptability,and diverse functionalities.However,conventional materials often failed to integrate these attributes simultaneously,hindering their applicability in next-generation technologies.Here,we present an organic-inorganic hybrid crystalline material with a unique sandwich-like architecture,in which a flexible organic crystal core is encased by reduced graphene oxide(rGO)and thermoplastic polyurethane(TPU).This strategic integration endows the material with fluorescence,cryogenic flexibility,and electrical conductivity,while also enabling dual sensing and actuation capabilities.The rGO layer facilitates real-time humidity(25-90%RH)and temperature(25-180℃)sensing through environmental interactions,whereas the differential thermal expansion between TPU and the flexible crystal core drives efficient photothermal actuation at-150℃ for advanced thermal regulation.The hybrid material exhibits stable performance under extreme conditions,making it a promising candidate for biomedical monitoring,flexible electronics,and energy applications.This work establishes hybrid crystalline materials as versatile and scalable platforms for addressing complex technological demands,paving the way for their application in next-generation multifunctional devices.
基金financially supported by Open project of Yunnan Precious Metals Laboratory Co.,Ltd.(No.YPML2023050245)Key Research and Development Program of Shaanxi(No.2022ZDLSF01-04)
文摘The field of disease smelling diagnosis has experienced a major breakthrough with the development of the electronic nose(E-nose)that utilizes thiol-capped gold nanoparticles(GNPs).This study focuses on overcoming the challenges of sensors to detect VOCs stably confounding with interferents of humidity and pressure,and clarifying their essential mechanism.An innovative and straightforward method for synthesizing GNPs and modifying their surface has been developed.This unique approach deviates from the conventional Brust method by completely removing any traces of tetraoctylammonium bromide(TOAB),ensuring reproducibility and simplicity of use.This modification enhances the sensor's responsiveness to both polar and non-polar VOCs,as well as strengthen selectivity and anti-interferant capabilities.The mechanism of generating sensing cross-talk from TOAB residue is proposed through rigorous sensing experiments,X-ray photoelectron spectroscopy(XPS)results,and theoretical analysis.Thus,this study enhances the responsiveness of the sensor to both polar and non-polar VOCs,while also strengthening its selectivity and anti-interferent capabilities.This could potentially revolutionize the practical applications of E-nose in smelling diagnosis.
基金supported by the Fundamental Research Funds for the Central Universities(WK2090000046).
文摘Relative humidity(RH)plays a pivotal role in regulating plant transpiration by modulating stomatal conductance().Accurate modeling under varying RH conditions is essential for predicting plant water use and gas exchange,with important implications for both agricultural management and bionic applications.In this study,field experiments were conducted to measure in plants exposed to moderate-and high-RH environments.The results demonstrated that is greater and transpiration rates are lower in high-RH environments than in moderate-RH environments.The response functions of stomatal conductance to environmental factors were further developed via a boundary line technique.These functions elucidate how stomatal conductance is correlated with environmental conditions.Specifically,stomatal conductance reaches saturation at a photosynthetically active radiation(PAR)of approximately 300 and 500μmol·m^(−2)·s^(−1) in both high-and moderate-RH environments.Furthermore,the vapor pressure deficit(VPD)threshold triggering stomatal closure was shifted by ambient RH,occurring at approximately 1000 Pa under high RH and 2000 Pa under moderate RH.This RH-dependent adjustment highlights the indirect yet critical role of RH in modulating stomatal sensitivity to atmospheric dryness.On the basis of the established response functions,stomatal conductance models tailored for high-and moderate-RH environments were constructed by extending the Jarvis empirical framework.These models offer improved predictive capacity for simulating plant physiological responses under diverse humidity conditions and provide new insights into the stomatal regulation of plants in natural field settings.
基金supported by the Natural Science Project of Zhengzhou Science and Technology Bureau(No.21ZZXTCX12)the Key Research and Development Program of Henan Province(No.221111220300)+1 种基金the Key Program of the National Natural Science Foundation of China(No.62333013)the Youth Backbone Teacher Training Program of Henan University of Technology(No.21420154).
文摘To facilitate real-time monitoring and recording of humidity in the environment and to satisfy the requirement for strain performance in certain applications(such as wearable devices),this paper proposes an in-situ method for synthesising Au nanoparticles on ZIF-67.In this study,an Au@ZIF-67 composite humidity-sensitive material was combined with flexible polyethylene terephthalate interdigitated electrodes to create an Au@ZIF-67 flexible humidity sensor.The prepared samples were characterised using X-ray diffraction,X-ray photoelectron spectroscopy,and transmission electron microscopy.The humidity-sensitive properties of the sensor were investigated,and its monitoring capabilities in applications involving respiration,gestures,skin,and baby diapers were tested.The experimental results indicate that compared with a pure ZIF-67 humidity sensor,the Au@ZIF-67(0.1Au@Z)flexible humidity sensor exhibits a 158.07%decrease in baseline resistance and a 51.66%increase in sensitivity to 95%relative humidity,and the hysteresis,response time,and recovery time are significantly reduced.Furthermore,the sensor exhibits excellent characteristics such as high resolution,repeatability,and stability.The obtained results regarding the material properties,humidity sensitivity,and practical application of non-contact humidity monitoring demonstrate that the prepared sensors exhibit excellent and comprehensive performance,indicating their broad prospects in wearable medical devices,wireless Internet of Things,humidity detection in complex environments,and intelligent integrated systems.
基金supported by the Natural Science Foundation of China(Grant Nos.42372220,42172207)the Youth Innovation Promotion Association Chinese Academy of Sciences(Grant No.Y2022102)+1 种基金the Science and Technology Innovation Project of Laoshan Laboratory(Grant No.LSKJ202203300)the International Partnership Program of the Chinese Academy of Sciences.
文摘The factors controlling dust activity and humidity in Central Asia and their relationships remain controversial,partly due to a lack of high-resolution geological records for the mid-to-late last glaciation.In this study,we established an optically stimulated luminescence chronology for the QSHA profile in the Yili Basin,a region influenced by westerlies.Grain size and trace element data were used as paleoclimatic indicators.We investigated the relationships among Central Asian dust activity,humidity,and westerlies strength on orbital to millennial scale from 37.4 ka to 11.6 ka.Our study reveals that,on orbital timescales,humidity is positively correlated with westerlies strength which controlled by precession.Dust activity is controlled by Siberian High which was regulated by Northern Hemisphere high-latitude temperature.Their responses to low-latitude and high-latitude forcing mechanisms respectively and present an opposite relationship.On millennial timescales,humidity and westerlies strength are positively correlated.During Marine Isotope Stage(MIS)2,humidity and dust activity show synchronous fluctuations,while during MIS 3,they exhibit an inverse relationship.Westerlies strength regulated humidity,which subsequently controlled glacial activity in the Tianshan Mountains,influencing dust activity in Central Asia.Additionally,the QSHA profile recorded seven Dansgaard-Oeschger(D-O)events on millennial timescales,indicating a potential link between Central Asian dust activity and high-latitude temperature variations in the Northern Hemisphere.Our findings provide new insights into dust and humidity interaction during the last glaciation periods in Central Asia and contribute to understanding global dust and hydrological cycles.
基金supported by the Science and Technology Development Fund(FDCT),Macao SAR(No.0149/2022/A),and(No.0046/2024/AFJ)Guangdong Science and Technology Department(No.2023QN10C305)。
文摘A high humidity-resistant,dual mechanical responsive,and reversible mechanochromic wrinkling system based on a VHB 4910-polydimethylsiloxane(PDMS)substrate with a thin film consisting of 90 wt%poly(vinyl butyral)(PVB)and 10 wt%hydroxypropyl cellulose(HPC)has been reported.The wrinkling system exhibited significant optical tuning from transparent to opaque states with 50%changes in transmittance,which was achieved through the dual mechanical modes of pre-stretching and releasing processes or bending.Upon exposure to ethanol vapor or a re-flattening process,wrinkles can be erased,yielding a transparent state.Consequently,the wrinkling system could be reversibly switched between transparency and opacity for 1000 cycles with marginal changes in the optical performance.Owing to the insolubility of PVB in water,the wrinkling patterns exhibited excellent durability in high-humidity environments(relative humidity(RH)=99%).Furthermore,the smart encryption device is also demonstrated via mechano-controlled surface topography by patterning the wrinkling system,suggesting potential applications of the designed structure in smart windows,anti-counterfeiting,dynamic display,optical information encryption,and rewritable surfaces.
基金supported by the National Natural Science Foundation of China (Nos.21876019 and 22276022)the National Key Research and Development Program of China (No.2019YFC1903903).
文摘Monolithic catalysts with excellent O_(3)catalytic decomposition performance were prepared by in situ loading of Co-doped KMn_(8)O_(16)on the surface of nickel foam.The triple-layer structure with Co-doped KMn_(8)O_(16)/Ni6MnO_(8)/Ni foam was grown spontaneously on the surface of nickel foam by tuning the molar ratio of KMnO_(4)to Co(NO_(3))_(2)·6H_(2)O precursors.Importantly,the formed Ni6MnO_(8)structure between KMn_(8)O_(16)and nickel foam during in situ synthesis process effectively protected nickel foam from further etching,which significantly enhanced the reaction stability of catalyst.The optimum amount of Co doping in KMn_(8)O_(16)was available when the molar ratio of Mn to Co species in the precursor solution was 2:1.And the Mn2Co1 catalyst had abundant oxygen vacancies and excellent hydrophobicity,thus creating outstanding O_(3)decomposition activity.The O_(3)conversion under dry conditions and relative humidity of 65%,90%over a period of 5 hr was 100%,94%and 80%with the space velocity of 28,000 hr^(−1),respectively.The in situ constructed Co-doped KMn_(8)O_(16)/Ni foam catalyst showed the advantages of low price and gradual applicability of the preparation process,which provided an opportunity for the design of monolithic catalyst for O_(3)catalytic decomposition.
基金financially supported by the National Natural Science Foundation of China(52203208,52325310,U24A6003,52303335)the National Key R&D Program of China(2021YFB3800101)+3 种基金the Beijing Nova Program(contract no.20230484480)the open research fund of Songshan Lake Materials Laboratory(2022SLABFK07)the Yunnan Provincial Science and Technology Project at Southwest United Graduate School(202302AO370013)the R&D Fruit Fund(20210001)。
文摘High-efficiency formamidinium lead iodide(FAPbI3)-based perovskite solar cells(PSCs)typically involve annealing in humid air during the fabrication process of perovskite films.However,the combined effects of humidity and relatively high temperature often result in the uncontrollable formation of a detrimental PbI_(2)phase in the perovskite films.As a result,the annealing process of perovskite films is highly sensitive to the relative humidity fluctuations of the environment.Under solar illumination,the undesired PbI_(2)tends to decompose,accelerating the degradation of perovskite materials and severely compromising the light stability of PSCs.This issue is particularly critical for the buried interface and bulk of the perovskite films,as these regions absorb the majority of the incident light.Pre-treatment and posttreatment strategies are generally confined to address the PbI_(2)issues at the buried interface and on the surface of the perovskite films,respectively.However,effectively addressing the effects of excess PbI_(2)at buried interface and grain boundaries within bulk in a single step remains challenging.In this study,we propose an intermediate-treatment strategy using phthalylglycyl chloride(PTC),which involves treating the wet films with PTC prior to annealing during the formation process of the perovskite films.This approach protects the grain boundaries of polycrystalline perovskite films in advance,effectively preventing moisture-induced degradation of the perovskites and thus significantly broadening the relative humidity window of annealing process.Our results demonstrate that this strategy can successfully suppress the formation of PbI_(2)at the grain boundaries and buried interface of perovskite films,thereby eliminating the PbI_(2)-induced degradation pathways.Our strategy significantly reduces the sensitivity to humidity fluctuations during annealing for fabricating stable PSCs,ensuring more consistent fabrication of stable PSCs.Consequently,the resulting PSCs achieve a champion power conversion efficiency of 26.1% and demonstrate excellent light stability.
基金supported by the National Natural Science Foundation of China(Nos.U23A6005,22208112,and 32171721)the National Natural Science Foundation of China(No.22308109)+2 种基金Guangdong Basic and Applied Basic Research Foundation(No.2024A1515010678)the Fundamental Research Funds for the Central Universities(SCUT:2023ZYGXZR045)the State Key Laboratory of Pulp&Paper Engineering(Nos.2023ZD01,2023C02).
文摘Proton exchange membrane fuel cell(PEMFC)is a promising clean energy source,but its performance and stability are vulnerable to the negative effects of humidity conditions.The gas diffusion substrate(GDS)plays a pivotal role in regulating the moisture and gas transport.The single pore structure of traditionally designed GDS often leads to the pathway competition between moisture and gas,which effects the efficiency of fuel cells.In this study,we report on a hierarchical fibrous paper with tunable hierarchical pores for a sustainable GDS.This design offers gas permeability under wet conditions,by separating the gas pathway from the moisture pathway,thus mitigating their pathway competition.In addition,this paper forms a multi-scale scaffold that absorbs moisture under high humidity conditions and releases it under dry conditions.It is allowed to maintain an optimal internal humidity and further enhances the humidity adaptability.Furthermore,the carbon footprint is only 15.97%,significantly lower than commercial alternatives.This feature makes it a sustainable solution to stabilize PEMFCs under diverse humidity conditions.
基金supported by the 261 Project of MIITthe National Natural Science Foundation of China(Nos.52250010,52201242,U23A20574)the Young Elite Scientists Sponsorship Program by CAST(No.2021QNRC001)。
文摘Halide solid-state electrolytes(HSSEs)with excellent ionic conductivity and high voltage stability are promising for all-solid-state Li-ion batteries(ASSLBs).However,they suffer from poor processability,mechanical durability and humidity stability,hindering their large-scale applications.Here,we introduce a dry-processing fibrillation strategy using hydrophobic polytetrafluoroethylene(PTFE)binder to encapsulate Li_(3)InCl_(6)(LIC)particles(the most representative HSSE).By manipulating the fibrillating process,only 0.5 wt%PTFE is sufficient to prepare free-standing LIC-PTFE(LIC-P)HSSEs.Additionally,LIC-P demonstrates excellent mechanical durability and humidity resistance.They can maintain their shapes after being exposed to humid atmosphere for 30 min,meanwhile still exhibit high ionic conductivity of>0.2m S/cm at 25℃.Consequently,the LIC-P-based ASSLBs deliver a high specific capacity of 126.6 m Ah/g at0.1 C and long cyclability of 200 cycles at 0.2 C.More importantly,the ASSLBs using moisture-exposed LIC-P can still operate properly by exhibiting a high capacity-retention of 87.7%after 100 cycles under0.2 C.Furthermore,for the first time,we unravel the LIC interfacial morphology evolution upon cycling because the good mechanical durability enables a facile separation of LIC-P from ASSLBs after testing.
基金The financial support from Project(Grant Nos.52278432,and 52168066)of National Natural Science Foundation of China and Project(Grant No.K2023G033)of the Science and Technology Research and Development Plan of China National Railway Group Co.,Ltd.were greatly appreciated.
文摘This paper presents a multi-scale experimental investigation of the weathering degradation of red mudstone.Natural rocks were extracted from the surface ground to 120 m,inwhich three sets of samples were selected to consider the different initial rock fabrics.The long-term relative humidity(RH)cycles under two amplitudes were imposed on red mudstone to simulate the weathering process.After RH cycles,a series of uniaxial compression tests,Brazilian splitting tests and bender-extender element tests were carried out to examine the reduction in strength and stiffness.The objective of this study is to develop an extended stress-volume framework characterizing the degradation of natural red mudstone both at microscale and macroscale.Accompanied by the irreversible swelling of the rock specimen is the progressive degradation of strength,stiffness and Poisson's ratio.A unified exponential degradation model in terms of the irreversible volumetric strain was thus proposed to capture such a degradation pattern.The effect of the initial rock fabric was evident.The highest degradation rate and potential were identified in slightly weathered specimens.Significant slaking of aggregates and crack propagation were confirmed by scanning electron microscope(SEM)micrographs,which were considered as the main consequence of structure damage leading to degradation of mechanical properties.The structure damage during RH cycles denoted the hysteresis nature in the response to the cycling hydraulic reaction,in turn causing the increase in volumetric strain.Thus,the stress-volume relation rather than the suction relation was found in more reasonable agreement with the experimental results.
基金supported by the National Key R&D Program of China(Nos.2022YFC3700400 and 2022YFC3704000).
文摘The large dynamic range and high performance of temperature and humidity profile lidar made it a popular tool for monitoring the atmospheric environment.In this study,we carried out an accurate analysis of the key components of the lidar system,including lasers,the emitting and receiving light paths,and photodetectors.We combined the validation of simulations with experimental testing,and then the applicability indicators and necessary conditions in accordance were suggested.For the frequency stability of the laser,when the wavelength shift is less than 0.15%,the measurement accuracy of the system can be guaranteed to be less than 5%.The degree of near-field signal distortion will be significantly impacted by the size of the geometric factor’s transition zone.The introduced measurement error is less than 2%when the deviation angle of the emission axis is less than 0.1 mrad.It has been tested that selecting a low-sensitivity detector can help to improve the sensitivity of temperature detection since this channel is sensitive to the detector’s nonlinearity.To enhance lidar’s detection capabilities and direct the lidar system design process,it is beneficial to analyze the precision of the key components.
基金supported by the Ondokuz Mayis University Project Number PYO.MUH.1901.21.001。
文摘Rare earth(RE)doped ferrites with the chemical formula Cu_(0.3)Zn_(0.3)Mg_(0.4)T_(x)Fe_(2-x)O_(4)(x=0,0.1;T=La,Ce,Sr)were synthesized by chemical co-precipitation method.The structural,optical,electrical and humidity sensing properties of Cu-Mg-Zn ferrites with rare earth element doping were investigated.Single-phase cubic spinel structure was confirmed via X-ray diffraction(XRD),and the crystal size ranges fro m 22.12 to 63.17 nm according to the Scherrer formula and from 25.66 to 67.46 nm according to the Williamson-Hall method.Po rous structure and elemental characterization of the samples were investigated by scanning electron microscopy(SEM).The optic band gap varies between 2.21 and 2.49 eV.Electrical measurements were conducted in the frequency range of 1 Hz-20 MHz and temperature range of 25-400℃.It has been determined that the dielectric results are consistent with the Maxwell-Wagner method and exhibit a non-Debye relaxation model,as observed from the Nyquist plots.At a minimum frequency value of 1 Hz,the dielectric constants for pure,Ce,Sr,and La samples are 9×10^(4),5×10^(4),1×10^(8),and 2×10^(5) at 25℃,and 1.85×10^(8),1.34×10^(8),1.15×10^(10),and 4.4×10^(8)at 400℃.In the same order,for the maximum frequency value of 20 MHz,the dielectric constants at 25℃are 169,166,3799,and 60,while at 400℃they are 734,624,12108,and 774.The La doped sample's low dielectric loss makes it suitable for high-frequency applications.Humidity measurements were performed at room temperature and in the 5%-95%relative humidity range.The humidity properties of the samples were investigated through humidity mapping,sensitivity,hysteresis,and long-term stability tests.Compared to other samples,the results indicate that Ce exhibits better humidity performance with 99%sensitivity and the highest repeatability(91.2%).These results show that Ce-doped ferrite can be used as a low-cost,high-performance humidity sensor.
文摘This paper presents a thermophysical study approach for a pure environmental control system(ECS),incorporating the geometric dimensions of heat exchangers,ram air duct,and air cycle machine(ACM)blades of the Sabreliner’s environmental control system.Real flight scenarios are simulated by considering flight input variables such as altitude,aircraft speed,compression ratio of the air cycle machine,and the mass flow rate of bleed air.The study evaluates the coefficient of performance(COP)of the environmental control system,the heat exchanger efficiencies,and the work distribution of the air cycle machine based on five flight scenarios,with a particular focus on considering the effects of humidity on environmental control system performance.The results demonstrate that at cruising altitude(11,000 m),air humidity conditions allow an increase in the COP of around 9.28%compared to dry conditions.Conversely,on land,humidity conditions reduce the performance by 4.26%compared to dry conditions.It was also found that the effects of humidity at high aircraft speeds become negligible.In general terms,the humidity conditions in the air proved to have positive effects on the environmental control system’s performance but negative effects on the heat exchanger efficiencies,reducing them by 0.22%.Additionally,land conditions reflect significant improvements in performance when the compression ratio of the air cycle machine is varied.Furthermore,in the work distribution of the air cycle machine,humidity conditions were demonstrated to consume 2.91%less work fromthe turbine compared to dry conditions.
文摘Based on ground observation data of relative humidity,the prediction performance of STNF and MIFS in each competition area during February 13-26,2024 was tested and evaluated by using two intelligent forecasting methods(STNF and MIFS).The results show that STNF had better performance in forecasting relative humidity in high-altitude areas,and was suitable for fine forecasting under complex terrain.MIFS improved the short-term forecast of some low-altitude stations,but the long-term reliability was insufficient.STNF method performed better than MIFS during 0-24 h.As the prediction time extended to 24-72 h,the errors of both methods showed a systematic increase trend.STNF had higher precision,lower root mean square error and smaller mean error in most regions under the background of most weather systems,showing its superiority as a forecasting method of relative humidity.However,the precision of MIFS was slightly higher than that of STNF in Liangcheng without system background,revealing that MIFS may also be an effective option in some specific conditions.
文摘As an indispensable part of modern buildings,centralized central air conditioning systems play an important role in maintaining the comfort and air quality of the indoor environment.However,with the increasing energy consumption,how to improve the energy efficiency ratio of air conditioning systems and reduce energy consumption has become an important issue in research and practice.The purpose of this paper is to discuss the impact of humidity control strategies on energy saving in centralized central air conditioning systems,with a view to providing a theoretical basis and practical guidance for realizing building energy efficiency.
基金Supported by Forestry Science and Technology Program of Hunan Province(XLK201406)~~
文摘Under the condition of high temperature, the effects of five cover patterns （clean tillage, film mulching, weed covering, branches and leaves covering and growing grass covering） on soil properties in young Phoebe boumei forest were in- vestigated. The results showed that the five cover patterns all showed significant ef- fects on soil properties in young Phoebe bournei forest under the condition of high temperature. Land cover increased land temperature in Phoebe boumei forest. Un- der the film mulching, the land temperature was increased most rapidly with the largest increment. However, weed covering, branches and leaves covering and growing grass covering decreased land temperature. Among them, growing grass covering showed the best cooling effect. The film mulching, weed covering, branch- es and leaves covering and growing grass covering all increased land humidity. The film mulching showed the best moisture-preserving effect in the early period, but in the late period, the humidity in the film mulching treatment group was lower than that in the clean tillage treatment group. Among the five mulching patterns, moisture loss in the film mulching treatment group was slowest and least, followed by those in the weed covering and branches and leaves covering treatment groups, and moisture loss in the growing grass covering treatment group was fastest and most.
基金Supported by Jiangsu Agricultural Science and Technology Innovation Fund[CX(14)2112]~~
文摘In order to analyze the ventilation and cooling performance of single-tunnel plastic greenhouse in Yangtze-Huai region, the effects of two different ventilation modes （side window, side window＋roof window） on the temperature and humidity of plastic greenhouse were studied. The results showed that the ventilation mode of opening side window and roof window could effectively reduce the temperature and humidity at the plant canopy height, which was conducive to the growth of plant in greenhouse.
