摘要：A new optical intensity-based sensing mechanism for the measurement of refractive index and minute displacement is proposed in this paper, which is based on modifying the amount of light coupled between two parallel long-period fiber gratings. The characteristics of this sensing mechanism with experiments and simulation results are demonstrated.

摘要：Submicron scale temperature sensors are crucial for a range of applications,particularly in micro and na-noscale *** promising solution involves the use of active whispering gallery mode(WGM)*** resonators can be remotely excited and read out using free-space structures,simplifying the process of *** this study,we present a submicron-scale temperature sensor with a remarkable sensitivity up to 185 pm/℃based on a trian-gular MAPbI3 nanoplatelet(NPL)***,as temperature changes,the peak wavelength of the laser line shifts *** unique characteristic allows for precise temperature sensing by tracking the peak wavelength of the NPL *** optical modes are confined within the perovskite NPL,which measures just 85 nm in height,due to total internal *** NPL laser boasts several key features,including a high Q of~2610 and a low laser threshold of about 19.8μJ·cm^(−2).The combination of exceptional sensitivity and ultra-small size makes our WGM device an ideal candidate for integration into systems that demand compact temperature *** advancement paves the way for significant prog-ress in the development of ultrasmall temperature sensors,opening new possibilities across various fields.

摘要：Surface plasmon resonance(SPR)of metals may provide a way to improve light absorption and utilization of semiconductors,achieving better solar light conversion and photocatalysis *** study uses the advantages of SPR in metallic Bi and artificial defects to cooperatively enhance the photocatalytic performance of *** catalysts were prepared by partial reduction of BiOI to form Bi@defective BiOI,which showed highly enhanced visible photocatalytic activity for NOx *** effects of reductant quantity on the photocatalytic performance of Bi@defective BiOI were *** as-prepared photocatalyst(Bi/BiOI-2)using 2 mmol of reductant NaBH4 showed the most efficient visible light photocatalytic *** enhanced activity can be ascribed to the synergistic effects of metallic Bi and oxygen *** electrons from the valence band tend to accumulate at vacancy states;therefore,the increased charge density would cause the adsorbed oxygen to transform more easily into superoxide radicals and,further,into hydroxyl *** radicals are the main active species that oxidize NO into final *** SPR effect of elemental Bi enables the improvement of visible light absorption efficiency and the promotion of charge carrier separation,which are crucial factors in boosting *** adsorption and reaction processes on Bi/BiOI-2 were dynamically monitored by in situ infrared spectroscopy(FT-IR).The Bi/BiOI photocatalysis mechanism co-mediated by elemental Bi and oxygen vacancies was proposed based on the analysis of intermediate products and DFT *** present work could provide new insights into the design of high-performance photocatalysts and understanding of the photocatalysis reaction mechanism for air-purification applications.

摘要：电子结构和电导率是析氧反应活性的重要描述符,它们可以通过掺杂来调节.鉴于金属掺杂通常会减少电催化剂的活性位点数量,本工作探究了阴离子掺杂对尖晶石钴酸锌(ZCO)电子结构及其析氧活性的影响.与三价钴为主的ZCO相比,用电负性较低的硫取代氧会提高低自旋态(t_(2g)-^(6)e_(g)^(1))二价钴的占比,其析氧活性要高于低自旋态的三价钴(t_(2g)-^(6)e_(g)^(0)).掺硫钴酸锌(ZCO-S)中钴离子和阴离子之间的电子密度的再分布导致了二价钴的增多,而且钴和硫离子间的强共价作用也会加速电荷迁移.ZCO-S在1.65伏(相对于可逆氢电极)下的比活性比原始ZCO高11倍.相反,掺入具有较高电负性和价态的氟(F)并不能有效地改善电子结构,最终导致材料析氧活性的降低.本工作建立了所掺阴离子的电负性与钴酸锌本征析氧活性之间的联系,并提供了一种通过掺杂不同电负性的阴离子来调控尖晶石氧化物的电子结构的简单有效的方法,这为合理设计高性能尖晶石电催化剂提供了新途径.

摘要：The DC-DC converters are widely used in photovoltaic generating systems as an interface between PV module and the load. These converters must be chosen to be able to match the maximum power point (MPP) of PV module when climatic conditions change with different resistive load values. So DC-DC converters must be used with MPPT controller in order to reduce losses in the global PV system. This article focuses on the effect of climatic conditions on design of two components (inductance, capacitance) for three topologies of DC-DC converters commonly used in PV systems. When climatic conditions change, the boundary of inductance and capacitance parameters of DC-DC converter will change. These two parameters must be properly sized to achieve optimal efficiency for each converter. The design optimization is based on two principles: 1) for a steady-state operation in a continuous conduction mode, the inductance value for all choppers must be greater than the maximum value of boundary inductance, and 2) in order to limit the output voltage ripple of DC-DC converter below a desired value, the filter capacitance must be larger than the maximum value of boundary capacitance.

摘要：鞭毛和纤毛独特的运动模式(如鞭毛的平面/螺旋波形式推进和纤毛的二维/三维不对称搏动)在众多生物的生命活动中起到至关重要的作用,这也启发了诸多仿生设计,尤其对于微型机器人系统。然而,与自然界中微生物能够从统一化的9+2轴丝生物结构中进化出多种运动模式不同的是,当前的仿生学仍然没有有效的工程策略去实现这样的智慧。在此,我们通过研究鞭毛和纤毛的内部结构及其内在驱动机制,推导出了一个统一的物理模型来描述微管弯曲及其所构建的宏观鞭毛/纤毛运动。基于该模型,我们进而提出了基于三通道的管状驱动概念,并相应地通过杆嵌入铸造工艺制造了一个三通道的管状驱动器。通过编程不同通道的驱动模式,这一管状驱动器不仅可以再现自然界中多样的二维及三维鞭毛/纤毛运动,还可以延展出更多的非对称纤毛搏动模式以实现低雷诺数下的有效推进。该研究加深了我们对微生物推进机制的理解,为仿生系统的设计提供了新灵感,并有望在广泛的工程领域中寻找到重要的应用场景。

摘要：Charge separation and transformation are some of the key requirements for high-efficiency photocatalysis. The photocatalytic reaction mechanism provides a guideline for the development and commercialization of high-efficiency photocatalysts. In this study, we designed and favorably synthesized BMO@BOC heterojunctions via a facile solvothermal route and applied the heat treatment method for application in high-efficiency photocatalytic NO removal. More importantly, both continuous stream and intermittent stream methods with in situ diffuse reflectance infrared Fourier transform spectroscopy were applied to intuitively and dynamically investigate the adsorption process and oxidation process of NO removal over the photocatalyst surface. The intermediate products(NO-, NO2-, and NO2) were explicitly detected in both the adsorption process and oxidation process, whilst the final product(NO3-) appeared only in the oxidation process, owing to the separation, migration, and conversion of photoinduced electron-hole pairs.

摘要：Third generation semiconductors for piezotronics and piezo-phototronics,such as Zn O and Ga N,have both piezoelectric and semiconducting *** devices normally exhibit high strain sensitivity because strain-induced piezoelectric charges control or tune the carrier transport at junctions,contacts and *** distribution width of piezoelectric charges in a junction is one of important ***-voltage(C-V)characteristics can be used to estimate the distribution width of strain-induced piezoelectric *** metal–insulator-semiconductor(MIS)has been modelled by analytical solutions and numerical simulations in this paper,which can serve as guidance for C-V measurements and experimental designs of piezotronic devices.

摘要：Optical control of exotic properties in strongly correlated electron materials is very attractive owing to their potential applications in optical and electronic ***,we demonstrate a vertical heterojunction made of a correlated electron oxide thin film VO_(2) and a conductive 0.05 wt% Nb-doped TiO_(2) single crystal,whose metal-insulator transition(MIT)across the nanoscale heterointerface can be efficiently modulated by visible light *** magnitude of the MIT decreases from ~350 in the dark state to ~7 in the illuminated state,obeying a power law with respect to the light power *** junction resistance is switched in a reversible and synchronous manner by turning light on and *** optical tunability of it is also exponentially proportional to the light power density,and a 320-fold on/off ratio is achieved with an irradiance of 65.6 mW cm^(-2) below the MIT *** the VO_(2) thin film is metallic above the MIT temperature,the optical tunability is remarkably weakened,with a one-fold change remaining under light *** results are co-attributed to a net reduction(~15 meV)in the apparent barrier height and the photocarrier-injection-induced metallization of the VO_(2) heterointerface through a photovoltaic effect,which is induced by deep defect level transition upon the visible light irradiance at low ***,the optical tunability is minimal,resulting from the quite weak modulation of the already metallic band structure in the Schottky-type junction above the MIT *** work enables a remotely optical scheme to manipulate the MIT,implying potential uncooled photodetection and photoswitch applications.

摘要：FeS因具有较高的比容量和优异的环境友好性,被认为是一种极具竞争力的锂/钠离子电池负极材料.然而,循环过程中缓慢的电荷转移动力学和较大的体积变化阻碍了它的实际应用.本文通过在超薄FeS/C复合材料中构建应变缓冲(气泡膜状)结构,从根本上解决了FeS动力学缓慢和体积变化大的问题.有限元模拟和非原位透射电镜结果验证了气泡膜状碳基质可作为保护壳层缓解FeS的巨大体积变化,还能提高其电子导电性.得益于这种独特的结构设计,该电极材料表现出显著增强的性能.其在5 A g^(-1)下的储锂容量为469 mA h g^(-1),在1 A g^(-1)下循环1500次后的储钠容量为354 mA h g^(-1).此外,由该电极与LiFePO_(4)正极组装的全电池即使在100次循环后也能提供558 mA h g^(-1)的比容量,展现出优异的循环稳定性.这一策略也可应用于其它导电性差、体积变化大的负极材料,以促进高倍率和长寿命电池的发展.