Research on synchronous measurement technique of temperature and deformation fields using multispectral camera with bilateral telecentric lens

The hot-section parts easily occur the creep-fatigued interaction under the condition of mechanicalthermal coupled load during the period of service, which may lead to the damage of the parts, and therefore, the measurement and characterization of thermal-deformed fields of the parts are important to understand its damage process. Aiming at relevant demand, the bilateral telecentric-multispectral imaging system was established, the research of synchronous measurement technique of the temperature and deformation fields was developed. On the one hand, the measurement technology for surface temperature of the object was developed using the two-color images captured by the multispectral camera with bilateral telecentric lens and combined with colorimetric method. On the other hand, the 2 D-DIC measurement technique of the multispectral camera was developed by conducting digital image correlation analysis using the blue light images before and after deformation, which can measure the high temperature deformation field of the object(the blue light images were filtered by multispectral camera).Results showed that the bilateral telecentric lens is used to replace the ordinary optical lens for imaging,which can effectively eliminate the distortion of the multispectral imaging system. Since the temperature measurement process of this measurement system is little affected by the emissivity of the object, therefore, it has excellent robustness. The thermal expansion coefficients of the nickel alloys are evaluated at the temperature ranges of 700–1000℃, indicating this system can achieve the synchronous and precise measurement of the temperature and deformation fields of the object.

Stretchable, self‐healable, and breathable biomimetic iontronics with superior humidity‐sensing performance for wireless respiration monitoring

Stretchable,self‐healing,and breathable skin‐biomimetic‐sensing iontronics play an important role in human physiological signal monitoring and human–computer interaction.However,previous studies have focused on the mimicking of skin tactile sensing(pressure,strain,and temperature),and the development of more functionalities is necessary.To this end,a superior humidity‐sensitive ionic skin is developed based on a self‐healing,stretchable,breathable,and biocompatible polyvinyl alcohol–cellulose nanofibers organohydrogel film,showing a pronounced thickness‐dependent humidity‐sensing performance.The as‐prepared 62.47‐μm‐thick organohydrogel film exhibits a high response(25,000%)to 98%RH,excellent repeatability,and long‐term stability(120 days).Moreover,this ionic skin has excellent resistance to large mechanical deformation and damage,and the worn‐out material can still retain its humidity‐sensing capabilities after self‐repair.Humidity‐sensing mechanism studies show that the induced response is mainly related to the increase of proton mobility and interfacial charge transport efficiency after water adsorption.The superior humidity responsiveness is attributed to the reduced thickness and the increased specific surface area of the organohydrogel film,allowing real‐time recording of physiological signals.Notably,by combining with a self‐designed printed circuit board,a continuous and wireless respiration monitoring system is developed,presenting its great potential in wearable and biomedical electronics.

超顺排的Bi_(2)O_(3)-多酸亚纳米线薄膜用于锂硫电池中间层

亚纳米线(SNWs)具有类高分子的性质,可以像高分子一样进行加工,而且其组成和结构易于调控,具有丰富的功能.合理设计多组分异质结构SNWs可以进一步提高其功能性,然而目前合成这种SNWs仍然面临着巨大的挑战.本文合成了Bi_(2)O_(3)-多酸异质结构SNWs(PMB SNWs),并制备了超顺排的PMB SNWs薄膜(S-PMB SNWs薄膜),该薄膜可以作为中间层,有效抑制多硫化锂(LPSs)的穿梭,从本质上促进LPSs氧化还原转化动力学,并对锂阳极起到保护作用.以S-PMB SNWs膜作为中间层的锂硫(Li-S)电池在850次循环中表现出超低的容量衰减率,每循环一圈只衰减0.013%.本研究证明了这种异质结构的SNWs具有改善锂硫电池性能的潜力.

Porousβ-FeOOH nanotube stabilizing Au single atom for highefficiency nitrogen fixation

Electrochemical nitrogen reduction reaction(NRR)under ambient conditions is highly desirable to achieve sustainable ammonia(NH3)production via an alternative carbon free strategy.Single-atom catalysts(SACs)with super high atomic utilization and catalytic efficiency exhibit great potential for NRR.Herein,a high-performance NRR SAC is facilely prepared via a simple deposition method to anchor Au single atoms onto porousβ-FeOOH nanotubes.The resulting Au-SA/FeOOH can efficiently drive NRR under ambient conditions,and the NH3 yield reaches as high as 2,860μg·h^(-1)·mg_(Au)^(-1)at-0.4 V vs.reversible hydrogen electrode(RHE)with 14.2%faradaic efficiency,much superior to those of all the reported Au-based electrocatalysts.Systematic investigations demonstrate that the synergy of much enhanced N_(2)adsorption,directional electron export,and mass transfer ability in Au-SA/FeOOH greatly contributes to the superior NRR activity.This work highlights a new insight into the design of high efficient NRR electrocatalysts by combination of porous metal oxide matrix and highly active single-atom sites.

Revealing the Flexibility of Inorganic Sub-Nanowires by Single-Molecule Force Spectroscopy

Sub-nanowires(SNWs),∼1 nm in thickness,possess an inorganic skeleton but display characteristics akin to those of carbon–carbon backbone polymers,such as flexibility,adhesion,gelation,self-assembling behaviors,and shear-thinning properties.Despite this,the underlying mechanism for these polymer-like properties remains unexplored.This study investigates the origin of SNWs’unique behavior from three distinct perspectives.Utilizing single-molecule force spectroscopy,we quantitatively measure the persistence lengths of SNWs,which provide a measure of flexibility.In addition,we evaluate the macroscopic mechanical properties of SNW materials,including the strength of electrospun fibers and gelation in solutions.Finally,we apply molecular dynamics to simulate the behaviors of SNWs under elongating and rotating conditions.The three perspectives mentioned above in the study collectively provide evidence for the structure-activity relationship of nanomaterials:a freely rotated backbone results in a flexible SNW,which is inclined to bend and entangle to form gels in solutions.Conversely,a stiff backbone leads to a rigid SNW,which induces strong fibers.