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Flexible and multifunctional humidity sensor based on Au@ZIF-67 nanoparticles for non-contact healthcare monitoring
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作者 Zhi-Hua Zhao Shi-Xin Ma +4 位作者 Ya-Fang Pan Abu-Bakker-Md Rahmatullah Xiao-Qing Shen Zhi-Gang Shao Lan Wu 《Rare Metals》 2025年第4期2564-2576,共13页
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
关键词 FLEXIBLE humidity sensor Au nanoparticles ZIF-67 MULTIFUNCTIONAL
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Orbital to millennial scale dust activity and humidity interaction in Central Asia during the last glacial period
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作者 Haoru Wei Yougui Song +7 位作者 Shugang Kang Mingyu Zhang Mengping Xie Yanping Wang Li Han Shukhrat Shukurov Nosir Shukurov Fakhriddin Fayziev 《Geoscience Frontiers》 2025年第4期433-445,共13页
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
关键词 Central Asian loess Orbital timescale Millennial timescale Dust activity humidity
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High Humidity-resistant and Reversible Mechanochromic Wrinkling Surface Activated by Dual Mechanical Modes
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作者 Cheng-Jun Yu Bin-Hong Yu Song-Shan Zeng 《Chinese Journal of Polymer Science》 2025年第7期1105-1113,共9页
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
关键词 Wrinkling surface Mechanochromism Optical modulation High humidity resistance PATTERNING
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Mitigating the pathway competition between moisture and gas via hierarchical fibrous paper for humidity-adaptive fuel cells
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作者 Peng He Lei Wang +4 位作者 Hao Tang Quanbo Huang Guodong Ren Ruwei Chen Xiaohui Wang 《Rare Metals》 2025年第5期3234-3243,共10页
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
关键词 PEMFC Biomass carbon paper substrate Hierarchical porous structure Moisture management humidity adaptability
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Co-doped cryptomelane-type manganese oxide in situ grown on a nickel foam substrate for high humidity ozone decomposition
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作者 Haoyuan Liang Xu Wang +1 位作者 Hui Wang Zhenping Qu 《Journal of Environmental Sciences》 2025年第2期529-540,共12页
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
关键词 Co-doped cryptomelane-type MANGANESE O_(3)decomposition High humidity Nickel foam Monolithic catalyst
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Reduced humidity sensitivity of the perovskite fabrication via intermediate treatment enabling stable perovskite solar cells
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作者 Hongyu Xu Qixuan Zhong +5 位作者 Yongqiang Ji Qiuyang Li Haoming Yan Yu Chen Rui Zhu Lichen Zhao 《Journal of Energy Chemistry》 2025年第7期133-141,共9页
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
关键词 Perovskite solar cells Intermediate-treatment strategy Relative humidity window High stability High efficiency
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Mechanical-durable and humidity-resistant dry-processed halide solid-state electrolyte films for all-solid-state battery
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作者 Mufan Cao Long Pan +10 位作者 Yaping Wang Xianwei Sui Xiong Xiong Liu Shengfa Feng Pengcheng Yuan Min Gao Jiacheng Liu Song-Zhu Kure-Chu Takehiko Hihara Yang Zhou Zheng-Ming Sun 《Chinese Chemical Letters》 2025年第6期657-662,共6页
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
关键词 Halide solid-state electrolytes Dry-process humidity resistance Mechanical durability All solid-state battery
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Degradation of natural red mudstone subjected to long-term relative humidity cycles
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作者 Kang Chen Rui Zhang +2 位作者 Shengyang Yuan Jie Ma Huan Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第9期5800-5815,共16页
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
关键词 Red mudstone Weathering degradation Relative humidity cycles Unified degradation model Microstructure tests
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Accuracy analysis of key components of temperature and humidity profile lidar
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作者 ZHANG Bowen LIU Wenqing +2 位作者 BAI Xuechun ZHANG Tianshu FAN Guangqiang 《Optoelectronics Letters》 2025年第11期648-654,共7页
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
关键词 monitoring atmospheric environmentin frequency stability experimental testingand geometric factor s transition zone validation simulations deviation angle temperature humidity profile lidar
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Effect of rare earth doping on structural,optical,dielectric,and humidity properties of Cu-Mg-Zn ferrites
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作者 Tuğba Şaşmaz Kuru Mehmet Kuru 《Journal of Rare Earths》 2025年第10期2257-2268,I0007,共13页
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
关键词 Cu-Mg-Zn ferrites humidity sensing Dielectric and impedance spectroscopy Rare earths
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Test and Evaluation of Relative Humidity Forecast in Each Competition Area of the "14 th National Winter Games" by Intelligent Forecasting Methods
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作者 Sitong LIU Xuefeng YANG 《Meteorological and Environmental Research》 2025年第1期37-40,共4页
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
关键词 Intelligent forecast Relative humidity Model test
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Study on the Impact of Humidity Control Strategy on Energy Saving Effect of Centralized Central Air Conditioning System
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作者 Xiaolian Lin 《Journal of Electronic Research and Application》 2025年第4期303-309,共7页
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
关键词 Centralized central air conditioning system Energy saving potential humidity control strategy Energy saving effect assessment
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Effects of Land Cover on Soil Temperature,Humidity and Moisture in Phoebe bournei Forest 被引量:9
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作者 吴际友 陈明皋 +5 位作者 董春英 黄小飞 黄明军 程勇 刘球 吴其军 《Agricultural Science & Technology》 CAS 2015年第12期2725-2729,共5页
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
关键词 Soil management Land cover Land temperature Land humidity Soil moisture
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Study on Temperature and Humidity of Plastic Greenhouse under Different Ventilation Modes in the Yangtze-Huai Region in Hot Season 被引量:1
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作者 孟力力 刘建龙 +3 位作者 柳军 夏礼如 唐玉邦 虞利俊 《Agricultural Science & Technology》 CAS 2016年第12期2885-2888,2900,共5页
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
关键词 Plastic greenhouse TEMPERATURE humidity Ventilation COOLING
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Analysis on the Climate Characteristics of Relative Humidity in Recent 40 Years in Urumqi City 被引量:2
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作者 李瑞 柳芳 +1 位作者 冉桂平 杨霞 《Meteorological and Environmental Research》 CAS 2010年第8期21-23,26,共4页
By using the daily average relative humidity data in Urumqi during 1961-2000,the basic climate characteristics and the variation trend of relative humidity in Urumqi in recent 40 years were analyzed.The results showed... By using the daily average relative humidity data in Urumqi during 1961-2000,the basic climate characteristics and the variation trend of relative humidity in Urumqi in recent 40 years were analyzed.The results showed that the yearly average relative humidity in Urumqi was 57.5%.The relative humidity in winter was 77.5% which was the biggest all the year round,and the relative humidity in summer was 41.2% which was the smallest.The relative humidity in spring,summer,autumn,winter and the yearly relative humidity all displayed the increase trend.The yearly mean relative humidity had the periods of mainly 2,3-4 and quasi-7 years.The periodic oscillation of quasi-7 years was the strongest. 展开更多
关键词 Relative humidity Climate variation Wavelet analysis Urumqi City China
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Impact of Relative Humidity of Supply Gas on Temperature Distributions in Single Cell of Polymer Electrolyte Fuel Cell When Operated at High Temperature 被引量:2
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作者 Akira Nishimura Masato Yoshimura +2 位作者 Satoru Kamiya Masafumi Hirota Eric Hu 《Journal of Energy and Power Engineering》 2017年第11期706-718,共13页
For improving the performance of stationary PEFC (polymer electrolyte fuel cell) system, the cell operating temperature up to 90℃ will be preferred in Japan during the period from 2020 to 2030. To understand the op... For improving the performance of stationary PEFC (polymer electrolyte fuel cell) system, the cell operating temperature up to 90℃ will be preferred in Japan during the period from 2020 to 2030. To understand the operation of the PEFC system under relatively high temperature conditions, detail heat and mass transfer analysis is required. The purpose of this study is to analyze the impact of relative humidity of supply gas on temperature distribution on the backside of separator in single ceil of PEFC using Nation membrane at higher temperature e.g. 90℃. The in-plane temperature distribution when power was being generated was measured using thermograph with various relative humidity of supply gases. It was found that the in-plane temperature distribution at the anode was more even than that at the cathode irrespective of the relative humidity of supply gas at the anode and the cathode. The temperature elevated along gas flow through the gas channel at the cathode irrespective of relative humidity of supply gas at the anode and the cathode. The in-plane temperature distribution at the cathode was narrower with the increase in Tini irrespective of relative humidity of supply gas at the cathode, while it was not observed when changing the relative humidity of supply gas at the anode. When the relative humidity of supply gas at cathode decreased, the in-plane temperature distribution at the anode was wider compared to decreasing the relative humidity of supply gas at the anode. The study concluded that the impact of relative humidity of supply gas at both anode and cathode had little impact on the in-plane temperature distribution at the cathode. 展开更多
关键词 PEFC temperature distribution high temperature operation relative humidity.
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Factors affecting relative humidity during wood vacuum drying 被引量:1
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作者 肖辉 蔡英春 《Journal of Forestry Research》 SCIE CAS CSCD 2009年第2期165-167,I0004,共4页
Effects of pressure and temperature in the chamber during vacuum drying on the relative humidity and evaporation of wood surface were investigated by using the vacuum chamber. The setting temperature during vacuum dry... Effects of pressure and temperature in the chamber during vacuum drying on the relative humidity and evaporation of wood surface were investigated by using the vacuum chamber. The setting temperature during vacuum drying included dry-bulb temperature ta, the wet-bulb temperature tw and the temperature difference between the air in the vacuum chamber and the cooling water in the condenser. Results indicated that relative humidity during vacuum drying was affected by the dry-bulb temperature td, the wet-bulb temperature tw and the temperature difference between the air in the vacuum chamber and the water in the condenser. Relative humidity of wood decreased with the increase in temperature at the given temperature of the water in the condenser. The relative humidity was affected slightly by pressure in the vacuum chamber pA, and it decreased from 70% to 65% with pA increased from 50 kPa to 101 kPa. Moreover, there was nearly no evaporation under the vacuum without external heating. 展开更多
关键词 influencing factors radio frequency relative humidity wood vacuum drying
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Evolution of rust layers on carbon steel and weathering steel in high humidity and heat marine atmospheric corrosion 被引量:30
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作者 Yueming Fan Wei Liu +6 位作者 Shimin Li Thee Chowwanonthapunya Banthukul Wongpat Yonggang Zhao Baojun Dong Tianyi Zhang Xiaogang Li 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2020年第4期190-199,共10页
The evolution of the rust layers on carbon steel and weathering steel in high humidity and heat marine atmospheric environment was investigated by wet/dry cyclic acceleration corrosion tests in this study.The corrosio... The evolution of the rust layers on carbon steel and weathering steel in high humidity and heat marine atmospheric environment was investigated by wet/dry cyclic acceleration corrosion tests in this study.The corrosion process of carbon steel and weathering steel was divided into two stages and the reasons for the changes in the corrosion rates of two steels were different.The composition phase of the inner rust layer of weathering steel was mainly goethite,whereas that of carbon steel was mainly akaganeite.Rust resistance(Rr)performed better than charge transfer resistance(Rt)in evaluating the protection performance of rust layer.As the corrosion proceeded,the evolution of the cathodic process of weathering steel was not obvious,whereas that of carbon steel was irregular. 展开更多
关键词 High humidity and HEAT marine ATMOSPHERE WEATHERING steel Cl ion RUST EVOLUTION
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Effects of relative humidity and PM2.5 chemical compositions on visibility impairment in Chengdu, China 被引量:25
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作者 Fan Liu Qinwen Tan +2 位作者 Xia Jiang Fumo Yang Wenju Jiang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2019年第12期15-23,共9页
To better understand the potential causes of visibility impairment in autumn and winter in Chengdu,relative humidity(RH),visibility,the concentrations of PM2.5 and its chemical components were on-line measured continu... To better understand the potential causes of visibility impairment in autumn and winter in Chengdu,relative humidity(RH),visibility,the concentrations of PM2.5 and its chemical components were on-line measured continuously in Chengdu from Nov.2016 to Jan.2017.Six obvious haze episodes occurred in Chengdu,with the total time of haze episodes accounted for more than 90%of the total observation period,and higher NO2 concentrations and RH were related to the high particle concentrations in haze episodes.The visibility decreased in a non-linear tendency under different RH conditions with the increase of PM2.5 concentrations,which was more sensitive to RH under lower PM2.5 concentrations.The threshold concentration of PM2.5 got more smaller with the increase of RH.During the entire observation period,organic matter(OM)was the largest contributor(31.12%to extinction coefficient(bext)),followed by NH4NO3 and(NH4)2SO4 with 28.03%and 23.01%,respectively.However,with the visibility impairment from Type I(visibility>10 km)to Type IV(visibility≤2 km),the contribution of OM to bextdecreased from 38.12%to 26.77%,while the contribution of NH4NO3 and(NH4)2SO4 to bextincreased from 19.09%and 20.20%to 34.29%and 24.35%,respectively,and NH4NO3 became the largest contributor to bextat Type IV.The results showed that OM and NH4NO3 were the key components of PM2.5 for visibility impairment in Chengdu,indicating that the control of precursors emissions of carbonaceous species and NH4NO3 could effectively improve the visibility in Chengdu. 展开更多
关键词 Visibility impairment PM2.5 chemical composition Relative humidity Light extinction coefficient Secondary formation
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Electrospinning of Flexible Poly(vinyl alcohol)/MXene Nanofiber-Based Humidity Sensor Self-Powered by Monolayer Molybdenum Diselenide Piezoelectric Nanogenerator 被引量:22
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作者 Dongyue Wang Dongzhi Zhang +3 位作者 Peng Li Zhimin Yang Qian Mi Liandong Yu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2021年第4期30-42,共13页
Two-dimensional material has been widely investigated for potential applications in sensor and flexible electronics.In this work,a self-powered flexible humidity sensing device based on poly(vinyl alcohol)/Ti_(3)C_(2)... Two-dimensional material has been widely investigated for potential applications in sensor and flexible electronics.In this work,a self-powered flexible humidity sensing device based on poly(vinyl alcohol)/Ti_(3)C_(2)Tx(PVA/MXene)nanofibers film and monolayer molybdenum diselenide(MoSe2)piezoelectric nanogenerator(PENG)was reported for the first time.The monolayer MoSe_(2)-based PENG was fabricated by atmospheric pressure chemical vapor deposition techniques,which can generate a peak output of 35 mV and a power density of42 mW m^(-2).The flexible PENG integrated on polyethylene terephthalate(PET)substrate can harvest energy generated by different parts of human body and exhibit great application prospects in wearable devices.The electrospinned PVA/MXene nanofiber-based humidity sensor with flexible PET substrate under the driven of monolayer MoSe_(2) PENG,shows high response of~40,fast response/recovery time of 0.9/6.3 s,low hysteresis of 1.8%and excellent repeatability.The self-powered flexible humidity sensor yields the capability of detecting human skin moisture and ambient humidity.This work provides a pathway to explore the high-performance humidity sensor integrated with PENG for the self-powered flexible electronic devices. 展开更多
关键词 Self-powered sensing Monolayer molybdenum diselenide Piezoelectric nanogenerator humidity sensor Flexible electronics
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