All-inorganic perovskite CsPbBr3 quantum dots (QDs) with an emission peak of around 520 nm were synthesized by a hot-injection method, and systematically studied as green phosphor for light-emitting diodes (LEDs). Highly pure light 534 full-width at half-maximum (FWHM) about 20 was achieved using QDs GaN LEDs. Commission Internationale Ed I'Eclairage coordinate the fabricated LEDs (0.203, 0.757). Compared to LEDs, current-voltage characteristic LED did not show any degradation. Moreover,...

A high-sensitivity photonic crystal fiber long-period grating (PCF-LPG) methane sensor with cryptophane-A-6Me absorbed on a poly(acrylic acid)-carbon nanotubes/ polypropylene amine hydrochloride (PAA-CNTs/PAH) nanofilm was investigated. The sensing film coated onto the internal surface of cladding air holes by an electrostatic self-assembly technique. Based finite element method and coupled local-mode theory, effects film's refractive index (RI) thickness resonant wavelength were...

This paper investigates the Frequency Modulation Continuous Wave (FMCW) radar sensor for multi-target displacement measurement in Structural Health Monitoring (SHM). The principle of three-dimensional (3-D) civil infrastructures is analyzed. requirements high-accuracy and identification measuring sensors are discussed. fundamental FMCW presented with rigorous mathematical formulas, further multiple-target analyzed simulated. In addition, a prototype designed fabricated based on an...

Utilizing the periodicity of rotating machinery, dynamic clearance measurement can be achieved with a single swept light source without any additional auxiliary devices, which has advantages simplicity and reliability. However, there is shortcoming that previous algorithm not fast enough to achieve real-time when machinery rotates at high speed. Aiming this shortcoming, utilizing correlation between mimic signal signal, combined information for multiple periods, algorithms corrected model...

This study presents a new intelligent control method, human-simulated (HSIC) based on the sensory motor schema (SMIS), for magneto-rheological (MR) suspension system considering time delay uncertainty of MR dampers. After formulating full car dynamic model featuring four dampers, HSIC eight SMIS is derived. A neural network proposed to compensate uncertain The then experimentally realized manufactured vehicle basis dSPACE platform. Its performance evaluated and compared under various road...

This paper presents a novel sensor design and application of long period fiber grating (LPFG) for detection methane. A styrene-acrylonitrile nano-film incorporating cryptophane A, which is sensitive to methane in close vicinity the surface, constructed onto cladding long-period grating. For optimal LPFG sensor, relationship between resonant wavelength shift complex refractive index sensing film analyzed based on coupled-mode theory. The change film, induced by methane, can easily be obtained...

Aiming at the problems of Doppler-induced error and slow measurement rate in frequency-swept interferometry, a novel dynamic clearance measuring method is proposed. By combining frequency-fixed using fusion processing interferometric signals, this not only can eliminate error, but also give value each sampling point. To verify method, an all fiber-optic system was constructed, experiments under 500 Hz triangular 4 kHz sinusoidal vibrations were carried out. Experimental results show that be...

Stress-induced birefringence can lead to distortion in the reflection spectra of fiber Bragg grating (FBG) sensors, thereby resulting loss accuracy and stability strain measurements. The bonding layer is a direct factor producing stress within FBGs. To assess impacts quantitatively, theoretical model that links spectrum was established. At same time, finite element method, based on model, used study relationships between characteristics detail. analytical results indicate high elastic...

If the measurand changes during spectrum acquisition process, it easily leads to failure of classic demodulation algorithms low-finesse optical fiber Fabry-Perot (FP) sensors. To address this problem, a novel model is proposed based on definition instantaneous frequency. The establishes relationship between path length (OPL) FP cavity and frequency distribution interference spectrum. link FFT algorithm discussed, found that can be viewed as generalized form algorithm. Based model,...

A health monitoring system was designed and installed on Dafosi Bridge, the largest cable-stayed bridge across Yangtze River in western China. This article briefly describes an online deflection system, most important sensing subsystem of system. It can be divided into two major components, one for measurement, control data processing. The measurement itself includes types sensors to monitor lateral displacement towers flexural torsional main girder. Sensor outputs are pre-processed locally...

With many steel strands used in various important machines and architectural structures, health monitoring of strand tension becomes more to ensure the equipment or structures' safety. Contrasted with method vibration frequency strain gages, measuring based on magneto-elastic effect is capable meeting requirements monitoring. Yet structure sensor mainly a sleeve structure, be measured serves as core primary secondary solenoids. This very difficult fix maintain. On other hand, change...

To realize accurate dynamic axial clearance measurement in high-speed rotating machinery using basic Frequency-swept interferometry (FSI), a novel algorithm of Doppler error suppression is proposed. In this algorithm, we first extract the incremental phase FSI signal by Hilbert transform and use it to construct virtual variation. Then, periodic characteristics rotor rotation, optimized initial can be obtained. Eventually, at each sampling point recovered with greatly suppressed. The...

Ag–In–Zn–S nanorods with tunable photoluminescence were synthesized by a facile approach.

Spectral distortions are complex and unpredictable in fiber Bragg grating (FBG) sensing applications. An inappropriate choice of FBG demodulation algorithm will lead to unacceptable results practice. Although many algorithms have been developed for distorted spectra, they may be limited some types spectral distortion. Until now, no model distortion has proposed test different algorithms. Here, we fulfill this aim by introducing a comprehensive with asymmetrical distortion, multi-peaks...

To better apply fiber Bragg gratings (FBGs) to various bending required situations, good understanding of their characteristics is crucial. In this Letter, a theoretical model describe the changes spectral properties an FBG against radius proposed. This shows that all bend-induced changes, shift center wavelength, decrease reflectivity, and reduction bandwidth, may be explained by effective "dc" refractive index change spatially averaged over one grating period. Experimental results are in...

Bonding layers, serving as the strain transmission mediums, may bring undesirable effects to sensing properties of fiber Bragg grating (FBG) sensors during their fatigue process. To analyze sensitivity and reflected spectrum FBG in different stages bonding sensitivities were derived according transfer models. Resorting T-matrix formalism, affected spectra stimulated. Theoretical analysis results show that there is a gradual decline stage crack initiation, significant distortions emerge...

We present a single longitudinal mode, diode pumped Nd:YVO(4) microchip laser where pair of quarter-wave plates (QWPs) sandwich and the principle axes QWPs are oriented at 45 degrees to c-axis Nd:YVO(4). Three pieces crystals were optically bonded together as without adhesive. Owing large birefringence Nd:YVO(4), two standing waves with orthogonal polarizations compensate their hole-burning effects each other, which diminish total spatial in The maximum pump power greater than 25 times...