Hot compression experiments of a Ti55511 titanium alloy are conducted to study the phase transformation characteristics and dynamic recrystallization (DRX) behavior. It is found that the fraction of ...α phase decreases with increasing the strain rate or deformation amount. Meanwhile, the original lamellar α phases easily transform into the spheroidal and bulk α phases at larger deformation amounts or higher strain rates. Most of α phases disappear and the final microstructures are mainly β phases when the temperature is over 800 °C. The DRX degree rises with raising the deformation amount or decreasing the strain rate. However, the DRX behavior becomes weaken with raising the deformation temperature. α phases are evenly distributed around β phases during hot compressive deformation, which not only restrains the growth of β phases but also promotes the DRX process of β phases. In addition, the geometric DRX takes place within α phases, while the continuous DRX occurs within β phases during the hot compression.
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•Phase transformation and dynamic recrystallization (DRX) behavior of a Ti55511 titanium alloy are studied.•The volume fraction of α phase decreases with increasing the strain rate or deformation degree.•Initial lamellar α phases easily transforms into bulk/spheroidal α phases at the larger strains or higher strain rates.•The α phases not only restrains the growth of β phase, but also promotes the DRX process of β phase.•The geometric DRX takes place within α phases, while the continuous DRX occurs within β phases.
The metadynamic recrystallization (MDRX) features of a Ni-based alloy with pre-precipitated δ phases (Ni3Nb) are researched by two-pass hot compressive experiments. Microstructural variations with ...deformation parameters are analyzed. Results reveal that the softening effects induced by MDRX become obvious at large first-pass strains, high strain rates or deformation temperatures, as well as the large percentage of pre-precipitated δ phase. At high deformation temperatures, the rearrange/annihilation of vacancies and dislocations are enhanced, which promotes the growth of substructures and the dissolution of δ phase. However, the coarsening of MDRX grains and the dissolution of δ phase become weaken with reducing the strain rate, first-pass strain or percentage of pre-precipitated δ phases. Considering the effects of pre-precipitated δ phases and deformation parameters on MDRX behavior, an improved kinetic model is proposed to predict the MDRX softening fractions. The forecasted results are well identical to the tested ones, which signifies the improved kinetic model can accurately evaluate the MDRX characteristics of the studied superalloy.
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•Metadynamic recrystallization (MDRX) features of a superalloy with pre-precipitated δ phases are researched.•Softening effects induced by MDRX are sensitive to deformation parameters and pre-precipitated δ phase.•Coarsening of MDRX grains and dissolution of δ phase become weaken with reducing pre-precipitated δ phase.•An improved MDRX kinetic model is developed considering the effects of pre-precipitated δ phases.
There is growing evidence that tripartite motif-containing protein 44 (TRIM44) plays crucial role in tumor development. However, the underlying mechanism of this deubiquitinating enzyme remains ...unclear.
Large clinical samples were used to detect TRIM44 expression and its associations with clinicopathological features and prognosis. Gain- and loss-of-function experiments in cell lines and mouse xenograft models were performed to elucidate the function and underlying mechanisms of TRIM44 induced tumor progression. Co-immunoprecipitation (Co-IP) assays and mass spectrometric analyses were applied to verify the interacting proteins of TRIM44.
We found that TRIM44 was commonly amplified in melanoma tissues compared with paratumoral tissues. TRIM44 expression also positively correlated with more aggressive clinicopathological features, such as Breslow depth (p = 0.025), distant metastasis (p = 0.012), and TNM stage (p = 0.002). Importantly, we found that TRIM44 was an independent indicator of prognosis for melanoma patients. Functionally, overexpression of TRIM44 facilitated cell invasion, migration, apoptosis resistance and proliferation in vitro, and promoted lung metastasis and tumorigenic ability in vivo. Importantly, high level of TRIM44 induced melanoma cell epithelial-mesenchymal transition (EMT), which is one of the most important mechanisms for the promotion of tumor metastasis. Mechanistically, high levels of TRIM44 increased the levels of p-AKT (T308) and p-mTOR (S2448), and a specific AKT inhibitor inhibited TRIM44-induced tumor progression. Co-IP assays and mass spectrometric analyses indicated that TRIM44 overexpression induces cell EMT through activating AKT/mTOR pathway via directly binding and stabilizing TOLL-like receptor 4 (TLR4), and TLR4 interference impeded TRIM44 induced tumor progression. Moreover, we demonstrated that TRIM44 is the target of miR-26b-5p, which is significantly downregulated in melanoma tissues and may be responsible for the overexpression of TRIM44.
TRIM44, regulated by miR-26b-5p, promotes melanoma progression by stabilizing TLR4, which then activates the AKT/mTOR pathway. TRIM44 shows promise as a prognostic predictor and a therapeutic target for melanoma patients.
A singlemode-multimode-singlemode (SMS) fiber structure consists of a short section of multimode fiber fusion- spliced between two SMS fibers. The mechanism underpinning the operation of an SMS fiber ...structure is multimode interference and associated self-imaging. SMS structures can be used in a variety of optical fiber systems but are most commonly used as sensors for a variety of parameters, ranging from macro-world measurands such as temperature, strain, vibration, flow rate, RI and humidity to the micro-world with measurands such as proteins, pathogens, DNA and specific molecules. While traditional SMS structures employ a short section of standard multimode fiber, a large number of structures have been investigated and demonstrated over the last decade involving the replacement of the multimode fiber section with alternatives such as a hollow core fiber or a tapered fiber. The objective of replacing the multimode fiber has most often been to allow sensing of different measurands or to improve sensitivity. In this paper, several different categories of SMS fiber structures, including traditional SMS, modified SMS and tapered SMS fiber structures are discussed with some theoretical underpinning and reviews of a wide variety of sensing examples and recent advances. The paper then summarizes and compares the performances of a variety of sensors which have been published under a number of headings. The paper concludes by considering the challenges faced by SMS based sensing schemes in terms of their deployment in real world applications and discusses possible future developments of SMS fiber sensors.
A low cost, wearable textile-based respiratory sensing system is proposed and experimentally demonstrated. A highly sensitive D-shaped plastic optical fiber (POF) sensor that responds to bending is ...integrated into an elastic band structure to form a respiratory sensing system. The curvature sensing experiments were conducted on the D-shaped POF sensor, which has a coefficient of determination (R 2 ) of 0.9977. The system can be used to monitor not only the respiratory rate (RR) of the human body under different movement states (resting, walking, and running) but also the RR of steady and unsteady respiratory signals due to different physiological states. In addition, using the proposed signal processing technique, the interference of motion noise can be removed and the influence of body movement on the sensor response can be eliminated. The advantages of the system are its low cost, compactness, and simplicity in design. Thus, the application of the proposed respiratory sensing system provides a simple and inexpensive optical solution for wearable health.
A new U-shape panda polarization-maintaining fiber (PPMF) based microfiber interferometer coated with graphene oxide (GO) film was proposed and experimentally demonstrated for relative humidity (RH) ...sensing. Experimental results show that the U-shape sensor has refractive index (RI) sensitivity of 1692.5 nm/RIU in the RI range of 1.33 when the diameter of the taper waist is 10.08 μm. The surface of the U-shape sensor was then modified chemically and coated with a thin layer of GO film (59.64 nm) for RH detection and the sensitivity is proportional to RH: as RH increases from 30% to 98%, the sensitivity increases from 0.111 to 0.361 nm/%RH and the response time is 0.28 s. In addition, the cross sensitivity to temperature, stability, reproducibility, and response/recovery time of the RH sensor were studied in detail. The proposed U-shape fiber RH sensor has advantage of high sensitivity, good reproducibility and fast response (0.28 s), which has potential application in areas requiring dynamic measurement of RH variations such as industrial product fabrication process control and breath state monitoring.
High-temperature compressive experiments of a Ni-based superalloy containing δ phase (Ni3Nb) are conducted. The dynamic dissolution behavior of δ phase in hot deformation process is quantitatively ...investigated. The dissolution mechanisms of δ phase are analyzed by Transmission Electron Microscopy (TEM) and first-principles calculations. Results reveal that the dissolution of δ phase is accelerated with increasing deformation temperature or deformation degree. But, the dissolution of δ phase becomes weaken as the strain rate is raised. The shear modulus (G) and bulk modulus (B) of δ phase decrease with increasing temperature or reducing pressure. The positive Cauchy pressure (C12–C44) and the larger ratio of B/G (greater than 1.75) reveal that δ phase is ductile at high temperatures or pressures. The intense interactions between dislocations and δ phase induce the stress concentration and the rapid diffusion of Nb atoms, which accelerate the precipitation/dissolution of δ phase. A phenomenological model is established for depicting the dissolution behavior of δ phase in hot deformation process. The measured results are identical with the forecasted ones, which demonstrates the established model is feasible to accurately depict the dynamic dissolution behaviors of δ phase in hot deformation process.
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•High-temperature compressive experiments of a Ni-based superalloy containing δ phase (Ni3Nb) are conduct.•The dissolution of δ phase is accelerated with increasing deformation temperature or true strain.•Local stress concentration induced by the interactions between dislocation and δ phases twists δ phases.•The dislocation-assisted Nb atoms diffusion play a major role for the dissolution of δ phases.•The developed model is feasible to predict the dissolution behaviors of δ phases during hot deformation.
Microstructural changes and flow characteristics of a nickel-based superalloy with pre-precipitated δ phases (Ni3Nb) are investigated using hot compressive experiments. The higher forming temperature ...or lower strain rate not only aggravate the arrangement/annihilation of dislocations, but also stimulate the generation/growth of substructures and dynamic recrystallization (DRX) grains. As the percentage of pre-precipitated δ phases is raised, the obvious work hardening behavior induced by the intense interactions between δ phases, grain boundaries and substructures occurs in the initial hot forming process. While the alloy is further strained, the DRX behavior are obviously promoted by δ phases. Considering the influences of pre-precipitated δ phases and forming parameters, an improved Hensel-Spittel-Carofalo (HSC) equation and an e-insensitive support vector regression (e-SVR) model are developed for reconstructing the flow features of the researched alloy. The minor deviations between the tested and forecasted true stresses indicate that the developed HSC model and e-SVR model can be properly utilized to characterize the hot forming features of the researched superalloy with different percentages of pre-precipitated δ phases.
•Hot forming behaviors of a nickel-base alloy with different pre-precipitated δ phase (Ni3Nb) are investigated.•Effects of forming parameters and δ phase on flow features and microstructural variations are significant.•Evolution of substructures is weaken at higher strain rate, while becomes obvious at higher forming temperature.•The increased pre-precipitated δ phase can aggravate the nucleation of substructures and DRX grains.•Flow features with pre-precipitated δ phase can be precisely reconstructed by HSC and e-SVR models
Optical whispering gallery mode (WGM) microbottle resonators based on a variety of polymer materials (benzocyclobutene (BCB), UV88 (Relentless, China) and Loctite3525 (HenKel, Germany)) were ...fabricated and investigated experimentally. The polymer materials were spin-coated onto the fiber and cured by ultraviolet (UV) light followed by heating to form a microbottle structure of different shapes and diameters. The WGMs were excited by tapered fiber, and the spectral characteristics of all realized microbottle cavities were evaluated, such as quality factor (Q > 10 4 ), free spectral range and polarization mode (TE and TM). The temperature and refractive index (RI) sensing performance are analyzed and Q-factor changes during the sensing process. In addition, a newly application of UV light intensity sensing for the polymer microbottle resonators was also demonstrated firstly. According to the experimental results that the microbottle resonator of BCB displays good UV light intensity sensitivity (0.0011 nm /( mw/cm 2 )) and figure of merit (FOM) (0.0122/( mw/cm 2 )). This sensor is a simple structure, low-cost material, robust performance, and possesses attractive application prospects in sensing and optical devices.
Wearable Human Machine Interface (HMI) is a medium for information transmission and exchange between people and computers. It is widely used in the fields of human motion capture and recognition and ...augmented/virtual reality (AR/VR). This research proposes a wearable plastic optical fiber (POF) sensing system based on machine learning for human motion recognition. The wearable sports sleeve is designed and worn on the elbow and knee joints of human body. The wearable sensor system uses a D-shaped plastic optical fiber (DPOF) sensor, whose coefficient of determination (R2) is 0.96496 and sensitivity is -0.7859% per degree. Support vector machines (SVM), MobileNetV2 network and transfer learning were used to identify six types of movement: walking, running, going upstairs, going downstairs, high leg lifts and rope skipping. The accuracy of classification based on the four joint position monitoring can reach 98.28%, 98.94% and 99.74%, respectively. The proposed POF wearable system has good applications for human motion state recognition and possesses great application potential in AR/VR.
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