Vibration measurement is a crucial task in industrial systems, where vibration characteristics reflect the health and indicate anomalies of objects. Previous approaches either work an intrusive manner or fail to capture micrometer-level vibrations. In this work, we propose mmVib, practical approach measure vibrations with mmWave radar. By introducing Multi-Signal Consolidation (MSC) model describe properties reflected signals, exploit inherent consistency among those signals accurately...

In this study, a long-distance optical frequency domain reflectometry (OFDR) with high spatial resolution based on time division multiplexing is proposed and experimentally demonstrated. Distributed strain sensing over long range can be realized by reconfiguring the system layout in time-division-multiplexed manner re-routing measurement signals for segmented processing extra circulators couplers only, rather than any other mechanisms performance improvement of laser source or algorithms...

In this study, a distributed multi-channel fiber-optic sensor for simultaneous measurement of relative humidity (RH) and temperature with finer gauge length based on spatial-domain time-delayed multiplexing is proposed experimentally demonstrated. Simultaneous acquisition signals can be realized by reconfiguring the system layout in manner re-routing Rayleigh backscattered split-channel processing using only extra delay fibers couplers instead any optical switches extending time or unit...

A complex medical instrument exterior shell was chosen as a studying object to investigate the influence of relative low (<10 MPa) gas counter pressure process on microcellular injection molding process. The mould and related experiments were designed. under which melt can foam mainly considered improve surface quality molded parts without significantly prolonging production cycle. effects parameters quality, cell morphology, density studied. critical flow front effectively eliminate...

The microcellular injection-molded part usually consists of a foamed core region and two unfoamed skin layers on the cross section. This paper investigated formation process, mechanism structural characteristics in part. It is found that are formed processes namely “during filling” process “after process. shear flow fountain behaviors melt filling stage main controlling factors layer cooling solidification fundamental reason for Further studies has distinct regions, outer thin frozen which...

A multiphase model was established to simulate the bubble morphological evolution in MFIM, and a new phenomenon of surface collapse pits with gradient depth discovered.

Rational design of small organic molecule-based NIR-II photosensitizers (PSs) with high singlet oxygen quantum yield in aqueous solution for deep tissue imaging and cancer therapy still presents challenges.

The accumulation of lipids in hepatocytes nonalcoholic fatty liver disease (NAFLD) leads to an increase reactive oxygen species and changes the intracellular microenvironment, while ferroptosis is result iron-dependent lipid peroxidation. Studies have shown that plays important role pathogenesis NAFLD. Herein, we developed a viscosity-sensitive fluorescence probe PTSO with near-infrared emission large Stokes shift, which were achieved by introducing sulfone group into...

A high-sensitivity temperature and curvature microfiber Mach-Zehnder interferometer (MMZI) with two peanut-shaped structures is proposed demonstrated for the first time. The consists of a section structures. can be easily affected by external environment due to its strong evanescent field on surface structure conducive excite fundamental mode high-order mode, which beneficial realize sensing detection. experimental results show that maximum sensitivity &#x2212;678.67 pm<inline-formula>...

In this study, a long-distance phase-sensitive optical time domain reflectometry (Φ-OTDR) with flexible frequency response based on division multiplexing is proposed and experimentally demonstrated. Distributed vibration sensing over long distance can be realized by reconfiguring the system layout in time-division-multiplexed manner re-routing Rayleigh backscattered signals for segmented processing extra erbium-doped fiber amplifiers added only instead of any other complex signal...

As a novel injection molding process, microcellular process has the characteristics of saving material, decreasing warpage and surface sink mark, improving dimensional accuracy, etc. But for plastic part with thick reinforcing ribs, if selection parameters are not reasonable, foaming quality melt will be affected obvious mark defects appear on part. This paper selected medical appliance shell many ribs as research object. Simulation experiments were performed by using orthogonal experiment...

The propagating phase changing of a polarization-maintaining photonic crystal fiber (PM-PCF) caused by temperature variation is theoretically studied, as well compared with conventional PANDA fiber. As to verifying numerical analysis, platform based on Michelson interferometer for versus measurement was built both kinds Experiments show that PM-PCF has similar sensitivity With optimized design (thinner coating layer and material smaller thermal expansion coefficient), the could be further...

In this study, a wide strain measurement range optical frequency domain reflectometry (OFDR) system based on self-correcting two-dimensional (2D) cross-correlation is proposed and experimentally demonstrated. Large events can lead to spatial mismatch caused by overstretching of the fiber, resulting in inaccurate demodulation spectrum during conventional OFDR data processing. The degradation signal similarity due be mitigated creating 2D array reference signals with different positional...

The frequency response of phase-sensitive optical time-domain reflectometry ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Phi $ </tex-math></inline-formula> -OTDR) is strictly limited by the repetition rate injected sampling pulses in conventional sensing scheme. To fully reconstruct an arbitrary vibration signal, pulse required to be lower bounded twice maximum signal according Nyquist theorem and at...

In this study, a high spatial resolution implementation method for optical frequency-domain reflectometry (OFDR) system based on convolution neural network (CNN) is proposed and experimentally demonstrated. the data processing flow, wavelength shift information obtained by cross-correlation operations between measurement signal reference each fiber segment arranged as function of sensing distance into 2-D images, when increased, cluttered regions present in can be equated to image noise...

Distributed polarization cross coupling (PCC) along the polarization-maintaining fiber (PMF), obtained from an optical coherence domain polarimetry (OCDP) system, is analyzed. It found that measured PCC data at each measurement location sum of OCDP source function centered a series discrete points, which do not represent true information. An algorithm developed to extract "true" and strength extracted are no longer dependent. A model relate in PMF coil optic gyro (FOG) bias drift due...

In order to improve the signal-to-noise ratio (SNR) of vibration sensing in phase-sensitive optical time-domain reflectometer (φ-OTDR) system, a fiber signal processing method based on FFDNet convolutional neural network is proposed this paper. network, concept residual learning introduced, which involves constructing mapping and utilizing multi-layer networks learn noise distribution present original image. The denoised result can be obtained by subtracting learned from We have built φ-OTDR...