Physical and emulsifying properties of pea protein:influence of combined physical modification by flaxseed gum and ultrasonic treatment

This study characterized and compared the physical and emulsifying properties of pea protein(PP)and its modified proteins(ultrasound treated-PP(PPU),flaxseed gum(FG)treated PP(PPFG)and ultrasound treated-PPFG(PPFGU)).The results showed FG triggered the formation of loosely attached complex with PP via physical modification under gentle magnetic stirring at pH 7.0,while ultrasound played an important role in reducing protein size,increasing surface hydrophobicity and molecular fluidity onto oil-water interface.So ultrasound further enhanced the interaction of PP with FG,and produced the PPFGU complex with smaller droplet size,higherζ-potential and lower turbidity.Further,combination of FG and ultrasound improved the physical properties of PP with higher viscosity,stiffer gels(defined as higher elastic modulus),stronger hydrophobic properties,better thermal stability,and fast protein absorption rate.Therefore,the PPFGU coarse emulsion performed highest emulsifying activity index(EAI)and emulsion stability index(ESI)that the stabilized nanoemulsion obtained smallest droplet size,higherζ-potential,and longest storage stability.The combination of FG and ultrasonic treatment will be an effective approach to improving the emulsifying property and thermal stability of PP,which can be considered as a potential plant-based emulsifier applied in the food industry.

开启物光新征程——纪念深圳大学建校40周年

深圳大学物理与光电工程学院是2019年1月15日根据学校学科调整,由原光电工程学院、物理与能源学院及电子科学与技术学院(光电相关部分)合并组建而成.其办学历史可以追溯到1985年建立的应用物理系.2006年,由原理学院应用物理系、核技术应用研究所和原师范学院物理教育系组建了物理科学学院,2015年12月物理科学学院更名为物理与能源学院.2006年由原工程技术学院电子科技系、光电信息系组建了电子科学与技术学院.2007年,在光电子学研究所基础上建立光电工程学院,在院(所)创始人牛憨笨院士的带领下,建立了围绕光电和测控领域的完整学科群.

基于Er^(3+)的力致温度传感

近年来,力致发光(ML)材料引起了科研人员的广泛关注,因其在众多领域特别是温度传感领域具有潜在的应用价值.值得注意的是,基于ML的温度传感尚处于萌芽期,且目前没有理论支持.本文中,我们基于CaZnOS:Er^(3+)力致发光材料和玻尔兹曼分布建立了ML温度传感技术的理论框架.在外部应力刺激下,CaZnOS:Er^(3+)力致发光材料能够发射出明亮的绿色荧光,且遵从玻尔兹曼分布理论.基于此,我们证实了该ML温度传感理论框架的适用性,并将其应用到实际案例中,即监测水壶的温度.与此同时,我们也开发了CaZnOS:Er^(3+)力致发光材料的多重功能,验证了其在动态防伪和信息加密提取方面的应用.简言之,本工作从实验和理论两方面进行研究,奠定了ML温度传感技术实用化的基础.

一种量身定制的双锥形光纤阵列使最先进的闪烁体成为可能

Scintillators, capable of converting X-/γ-ray to light, find widespread applications in medical diagnostics, industrial product inspection, security screening, and high-energy physics [1], [2]. Despite the significant success, the growing need of peeking deep into matters in different modalities calls for the revolution of current scintillators. Apart from the ongoing goal of reducing radiation dosage, entailing scintillators with mechanical flexibility and ultrahigh spatiotemporal resolution is now at the forefront [3], [4]. For example, if the scintillator is made flexible, three-dimensional (3D) imaging of curved objects can be enabled without the use of multi-angle scanning and algorithmic image reconstruction [5].

先进仿生皮肤的力致发光材料

Mechanoluminescence(ML)materials that convert the external mechanical energy into light emission without the assistance of electron or photon excitation have been emerging because of their promising application in infrastructure health monitoring,information safety,novel light sources and displays,energy harvesting,aerospace engineering,soft electronics,smart robotics,the Internet of Things,and biomedicine[1].The documented record of ML can be retrospect to 1605,Francis Bacon described mechanically-induced light emission during the scraping of the hard sugar with a knife“sugar shineth only while in scraping”in his celebrated work on“Of the proficience and advancement of learning,divine and human”[2],while the ML observed from the striking stone or quartz by the primitive man may have been a million years.To date,a myriad of MLmaterials covering conductor,semiconductor and insulator have been discovered or synthesized,especially after the development of photomultiplier tube in the mid-20th century,with a conservative estimation of half of inorganic crystals and third of organic compounds harboring ML[3].ML can be categorized into deformation luminescence and triboluminescence according to the physical process involved in inducing luminescence.

Controlled fabrication, lasing behavior and excitonic recombination dynamics in single crystal CH3NH3PbBr3 perovskite cuboids

As a direct bandgap semiconductor, organic-inorganic lead halide perovskite (MAPbX3, MA = CH3NH3, X =Cl, Br, I) have been considered as promising materials for laser due to their excellent optoelectronic properties. The perovskite materials with ID and 2D shapes were widely prepared and studied for Fabry-Perot mode and whispering-gallery-mode (WGM) microcavities, but cuboid-shape is rarely reported. In this work, we successfully fabricated single crystal cuboid-shaped MAPbBr3 perovskite w让h different morphologies, named microcuboid-MAPbBr3 (M-MAPbBr3) and multi-step-MAPbBr3 (MSMAPbBr3), via solvothermal method. Furthermore, the as-prepared *crystals excitonic recombination lifetime under different pumping energy density was studied by time-resolved photoiuminescence (TRPL). Based on controllable morphology and remarkable lasing properties, these cuboid shaped single crystal perovskite could be a promising candidate for small laser, and other optoelectronic devices.

一种应力诱导发光的新型材料——MgF_(2):Mn^(2+)

应力发光材料可以直接将外部机械刺激转化为光,而无需其他形式的能量(如光或电)激发.这种诱人的特性使该类材料在许多领域都具有应用前景,如应力动态成像、光学信息存储和防伪加密等.尽管很多无机物都有应力发光现象,但其发光性质不甚理想.在提升发光性能与探寻发光机制、推进其实用化的进程中,寻求新的材料体系和结构显得尤为必要.本文成功开发了一种新型的自激活应力发光新材料——MgF_(2):Mn^(2+),当对其施加外部动态压力时可发出明亮的红光,无需用紫外灯预先充能.同时,基于MgF_(2):Mn^(2+)和聚二甲基硅氧烷,本文成功制备了高度透明的应力发光薄膜,有望在柔性光电子领域例如人造皮肤上得到应用.最后,通过对照实验证实,在Mg F_(2)体系中,应力发光和余辉基本没有关联,暗示了应力发光的能量传递过程可能是局域性的,这为揭示应力发光机理提供了新的视角,也为设计新颖的应力发光材料指明了方向.

应力发光材料助力运动分析

Life lies in movement,and sport is one of the most important parts in our life.With the development of advanced science and technology,such as the Internet of Things and big data,sports science has experienced some revolutionary changes[1].This raises a higher demand to the body and health conditions and promotes various athletic events in terms of entertainments,exercises and competitions.

外延-剥离技术实现单晶钙钛矿的可控制备

The intriguing attributes of organic-inorganic hybrid perovskites,such as excellent carrier dynamics,outstanding optical tunability,and cost-effective solution processability,have put them on par with or even to be partially superior over the conventional semiconductors,enabling a myriad of applications including solar cells.

Mechanoluminescent hybrids from a natural resource for energy-related applications

Mechanoluminescent(ML)materials that directly convert mechanical energy into photon emission have emerged as promising candidates for various applications.Despite the recent advances in the development of both novel and conventional ML materials,the limited access to ML materials that simultaneously have the attributes of high brightness,low cost,self-recovery,and stability,and the lack of appropriate designs for constructing ML devices represent significant challenges that remain to be addressed to boost the practical application of ML materials.Herein,ML hybrids derived from a natural source,waste eggshell,with the aforementioned attributes are demonstrated.The introduction of the eggshell not only enables the preparation of the hybrid in a simple and cost-effective manner but also contributes to the homochromatism(red,green,or blue emission),high brightness,and robustness of the resultant ML hybrids.The significant properties of the ML hybrids,together with the proposed structural design,such as porosity or core–shell structure,could expedite a series of mechanic-optical applications,including the self-luminous shoes for the conversion of human motions into light and light generators that efficiently harvest water wave energy.The fascinating properties,versatile designs,and the efficient protocol of“turning waste into treasure”of the ML hybrids represent significant advances in ML materials,promising a leap to the practical applications of this flouring material family.

Interface synergistic effects induced multi-mode luminescence

Mechanoluminescence(ML)has become the most promising material for broad applications in display and sensing devices,in which ZnS is the most commonly studied one due to its stable and highly repetitive ML performances.In this work,we have successfully prepared the biphase ZnS on a large scale through the facile in-air molten salt protection strategy.The obtained biphase has the best ML properties,which is mainly attributed to the synergistic effects of piezo-photonic,defect,and interface dislocations.DFT calculations have confirmed that the defects activate the local S and Zn sites and reduce the energy barrier for electron transfer.The much stronger X-ray induced luminescence than the commercial scintillator is also reached.The application of ZnS particles in both papers and inks delivers superior performance.Meanwhile,ZnS particles based screen printing ink is able to directly print on paper,plastic and other carriers to form clear marks.These proposed paper and ink hold great potentials in applications of information security and anti-counterfeiting based on the multi-mode luminescence properties.This work provides a new avenue to understand and realize the high-performance multi-mode luminescence,inspiring more future works to extend on other ML materials and boosting their practical applications.

Hydrothermal synthesis of monodisperse α-Fe_2O_3 hexagonal platelets

Uniformly sized α-Fe2O3 hexagonal platelets were synthesized by a hydrothermal process using Fe（OH）3 suspension and large amount of NaOH. The reaction products were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, selected area electron diffraction （SAED）, and a vibrating sample magnetometer （VSM）. The results show that the hexagonaq platelets are fine, monodisperse and consisting of single-crystals. The magnetic hysteresis （M-H） curvel of the samples measured at room temperature indicates that the α-Fe2O3 micro-platelets exhibit ferromagnetic behaviors with relatively low coercivity.

Photoluminescence and thermal stability of yellow-emitting Pr^(3+) doped CaAl_(2)O_(4) phosphors

Pr^(3+)-doped CaAl_(2)O_(4) phosphors with broad yellow emission were synthesized by conventional solid-state reaction in air and their structural and luminescent properties were investigated.A pure monoclinic structure can be obtained when the sintering temperature is 1400℃ or above.With photoluminescence(PL)measurement,the excitation was observed at 450–500 nm,which covered the emission of the blue light-emitting diode(LED)chips.Emission of the phosphors showed a green band and a red band.So these phosphors showed great potential in application of warm white LEDs without reabsorption.Additionally,the optimal emission intensity was obtained when Pr doping level was at 0.2 mol%.Furthermore,the Pr-doped CaAl_(2)O_(4) phosphors have the higher quenching temperature.With an increase in temperature,the emission bands of Pr-doped CaAl_(2)O_(4) showed an abnormal blue-shift.

Halogen-doped phosphorescent carbon dots for grayscale patterning

Flexible organic materials that exhibit dynamic ultralong room temperature phosphorescence(DURTP)via photoactivation have attracted increasing research interest for their fascinating functions of reversibly writing-reading-erasing graphic information in the form of a long afterglow.However,due to the existence of a nonnegligible activation threshold for the initial exposure dose,the display mode of these materials has thus far been limited to binary patterns.By resorting to halogen element doping of carbon dots(CDs)to enhance intersystem crossing and reduce the activation threshold,we were able to produce,for the first time,a transparent,flexible,and fully programmable DURTP composite film with a reliable grayscale display capacity.Examples of promising applications in UV photography and highly confidential steganography were constructed,partially demonstrating the broad future applications of this material as a programmable platform with a high optical information density.

基于二维钙钛矿的连续激光

Miniaturized lasers at the micro-and nanoscale are highly attractive for applications in sensing,lighting,display,and highly-integrated photonic devices because of their advantages of low noise and good spectral purity[1–3].Since the first demonstration of amplified spontaneous emission(ASE)behavior in solution-based CH3NH3Pb X3perovskite film in 2014[4],both pulsed and continuous-wave(CW)lasing have been realized in various metal halide perovskites due to their superior attributes[5,6].

有机物染料与镧系掺杂的无机纳米颗粒之间清晰的作用机理

Lanthanide-doped nanoparticles,which contain lanthanide ions doped in an inorganic host,can generate wide wavelength range emissions corresponding to inner shell 4 f-4 f transitions of lanthanide ions[1–3].Unfortunately,lanthanide 4 f transitions have a narrow absorption band and small absorption cross-section(10-20 cm2)when compared with organic dye molecules(around10-17–10-16 cm2),posing a critical brightness performance limit of lanthanide ions[4,5].

Up-conversion luminescence of Er^(3+)and Yb^(3+)co-doped CaBi_(2)Ta_(2)O_(9) multifunctional ferroelectrics

Er^(3+)and Yb^(3+)co-doped CaBi_(2)Ta_(2)O_(9)(CBT)-based bismuth layered-structure oxides were synthesized by a simple solid-state reaction method.Their up-conversion(UC)luminescence,dielectric and ferroelectric properties were investigated.Two strong green emission bands centered at 526 and 547nm and a weak red emission band centered at 658nm were obtained under a 980nm laser excitation at room temperature.These emission bands originated from the radiative relaxation of Er^(3+)from 2H_(11)=2,4S_(3)=2,and 4F_(9/2) levels to the ground state 4I_(15)=2,respectively.At the meantime,the fluorescence intensity ratio(FIR)variation of two green UC emissions at 526 and 547nm has been studied as a function of temperature in the range of 153–603K.The maximum sensor sensitivity obtained was 39×10^(-4)K^(-1) at 590K,which indicated that Er^(3+)=Yb^(3+)co-doped CBT ceramic is a promising candidate for applications in optical high temperature sensor.

A time-dependent luminescent phosphor of Na_(2)Ba_(2)Si_(2)O_(7):Eu for multi-level encryption and dynamic information display

Photo-stimuli responsive materials show great potential in the fields of information encryption and storage due to their distinctive spatial or temporal color changes.However,the conventional single or multi-color static outputs by light stimulus difficulty meet practical requirements for high-security optical storage technologies.Here,a novel dynamic irradiation-responsive phosphor of Na_(2)Ba_(2)Si_(2)O_(7):Eu is demonstrated,exhibiting high storage stability and convenient readout behaviors.The inherent Eu^(2+)luminescence can be dynamically tuned,instantly read out,and conveniently erased by controlling irradiation duration of a portable diode laser(365 nm).The modulation mechanism is unraveled by optically induced oxidation reactions of Eu^(2+)→Eu^(3+)and defects as killer centers.The excellent luminescence modulation degree(ΔRt=89.5%)and the accompanying larger color contrast enable the creation of invisible optical codes with multi-level encryption in bright or dark field.These results indicate potential applications of Na_(2)Ba_(2)Si_(2)O_(7):-based materials in information encryption and invisible optical storage,and are expected to expand more investigations on optically induced PL modulation behaviors based on mixed valences and defects.