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Lateral erosion is a critical factor that influences the formation and amplification of debris flows. However, our understanding of the bank retreat process in debris flow channels is limited, which limits the evaluation of debris flow magnitudes and the prediction of their activity trends. Herein, we conduct physical experiments to investigate bank retreat mechanisms using five types of bank soil and multiple debris flow surges. The bank retreat process is categorized into two stages: toe cutting and bank collapse. Toe cutting is mainly caused by hydraulic erosion, bank collapse includes gravity erosion in the form of toppling failure. Notably, the bank retreat process exhibits a significant negative feedback loop. Bank erosion widens the channel bed, subsequently decreasing the flow depth. In turn, this reduction in flow depth mitigates bank erosion. Moreover, we discover a concise pattern in the complex coupling of hydraulic erosion and toppling failure: erosion efficiency is linearly and negatively correlated with the bed widening width. We develop a new parameterized model for describing the bank retreat process and provided empirical values for the model parameters. Furthermore, we observe that the initial erosion efficiency first increases and then decreases with an increase in the fine particle content of the bank soil. Additionally, we report a negative correlation between the maximum bed widening width and the fine particle content in the bank soil that follows a power function relationship. Key Points: We revealed the feedback mechanism between bank retreat and debris flow erosion efficiencyWe established a parameterized model describing the bank retreat processWe discussed the relationships between the model parameters and the particle size distribution of the bank soil [ABSTRACT FROM AUTHOR]

In this paper, the theoretical analysis of 2.3 GHz bulk acoustic wave (BAW) resonators with emerging ε-Ga2O3 piezoelectric films was investigated. By using the finite element method to calculate the dispersion curve of the BAW resonator based on ε-Ga2O3, we designed and optimized the Bragg reflector structure as well as the metal frame to suppress transverse energy leakage. When the width of the raised metal frame is an odd multiple of the quarter wavelength of the S1 Lamb mode, the vibration displacement at the boundary of the resonators is significantly suppressed, and the acoustic energy is concentrated as much as possible in the effective area of the resonators, resulting in improvement of the Qp and Qmax. Therefore, the ε-Ga2O3 based BAW resonators with Bode Qmax (∼1488), electromechanical coupling coefficient k2eff (∼15%), and the figure of merit (FoM) coefficient (∼223) are simulated and designed. Detailed theoretical analysis provides the key theoretical guidance and design scheme for the realization of ε-Ga2O3 BAW filters. The above-mentioned results imply that the emerging ε-Ga2O3 piezoelectric semiconductors have application prospects in BAW resonators and radio frequency front-end fields. [ABSTRACT FROM AUTHOR]

The comparison and analysis of piezoelectric properties for [001]-oriented PMN-0.30PT by different polarization conditions were investigated. It should be noticed that the average piezoelectric coefficients d33 of PMN-0.30PT crystals were 1860 pC/N by alternating current (AC) polarization and 1380 pC/N by direct current (DC) polarization, which indicates a promotion of 35.3%. The domain patterns in the [001] surface of PMN-0.30PT single crystals under different polarization conditions are obtained by piezo-response force microscopy. The enhancement of piezoelectric performance by AC polarization is attributed to the regular stripe domains with high domain wall density. With the temperature increased to TR-T, both the values of dielectric constant ε r T and piezoelectric coefficients d33 under AC polarization condition maintain higher compared to traditional DC poled samples. In addition, both the values of e 33 and ε 33 S under AC polarization retain higher than that of DC polarization, suggesting that the special domain structure with high domain wall density by AC polarization keeps a stable state as the temperature increased to TR-T. When the temperature increased from TR-T to TT-C, the piezoelectric properties of crystals (ε r T and d33) under different polarization conditions become the same status, which indicates that the domain structure under the different conditions of polarization may tend to the similar state and the extrinsic contribution from the domain wall motion by AC polarization is disappeared. [ABSTRACT FROM AUTHOR]

The [111]‐oriented rhombohedral Mn‐doped 0.15Pb(In1/2Nb1/2)‐0.55Pb(Mg1/3Nb2/3)O3‐0.30PbTiO3 (Mn:PIMNT(15/55/30)) crystal and the [001]‐oriented tetragonal Mn‐doped 0.29Pb(In1/2Nb1/2)‐0.29Pb(Mg1/3Nb2/3)O3‐0.42PbTiO3 (Mn:PIMNT(29/29/42)) crystal were poled under different conditions. The pyroelectric performance of the two crystals as a function of poling temperature, as well as the relationship with ferroelectric domain configuration and phase structure was investigated systematically. The pyroelectric properties of the two crystals enhance with rising the poling temperature, which can be attributed to the improvement of the single state. And for the rhombohedral Mn:PIMNT(15/55/30) crystal locating near morphotropic phase boundary (MPB), the increase of tetragonal phase induces the deterioration of pyroelectric properties. Due to more residual tetragonal phase, the pyroelectric coefficient of the Mn:PIMNT(15/55/30) crystal poled at 150°C is lower than that poled at 100°C. In general, both the crystals poled above TC achieve nearly single state, exhibiting the best pyroelectric properties with relatively high Curie temperature (TC), where P = 9.71 × 10−4 C m−2 K−1, Fi = 3.88 × 10−10 m V−1, Fv = 0.068 m2 C−1 and Fd = 29.7 × 10−5 Pa−1/2 for the rhombohedral Mn:PIMNT(15/55/30) crystal (TC = 171°C) and P = 6.78 × 10−4 C m−2 K−1, Fi = 2.71 ×10−10 mV−1, Fv = 0.1 m2 C−1, Fd = 23.54 × 10−5 Pa−1/2 for the tetragonal Mn:PIMNT(29/29/42) single crystal (TC = 251°C), meeting the stable operation of infrared detector at relatively high environmental temperatures. [ABSTRACT FROM AUTHOR]

Highlights • The k33 of PMNT crystal keeps at 0.86–0.87 when the G < 0.7 as well as a pure height-extensional mode was obtained. • PMNT array shows more than 27.7% broader -6 dB bandwidth, 5.2 dB higher relative sensitivity compared to the PZT array. • PMNT array has the same good consistency of the performance as the PZT array. • The imaging which uses the PMNT array has the better definition and resolution compared to those of PZT array. Abstract The design, fabrication and comparison of PMN-PT single crystals and PZT ceramics based 3 MHz phased array ultrasonic transducers were investigated. The resonance mode and electromechanical properties for PMN-PT single crystal were simulated by using the COMSOL Multiphysics software. Simulation results indicate that the electromechanical coupling coefficient k 33 ' keeps at 0.86–0.87 when the aspect ratio G < 0.7, as well as a pure height-extensional mode was obtained. Two types of ultrasonic phased arrays using PMN-PT single crystal and PZT ceramic were fabricated and compared. The experimental results revealed that more than 27.7% broader -6 dB bandwidth, 5.2 dB higher relative sensitivity, and shorter pulse length can be obtained by using PMN-PT single crystal compared to the PZT array. The experimental results agreed well with the predictions of simulation by using the PiezoCAD software. Furthermore, PMN-PT array has the same good consistency of the performance as the PZT array, while the better acoustic performance and higher electromechanical properties compared to PZT array as a whole. In the end, the ultrasonic imaging which uses the PMN-PT based array transducer has the better definition, the higher axial resolution and lateral resolution compared to those of PZT based array transducer. [ABSTRACT FROM AUTHOR]

In situ observations of the phase symmetry and domain evolution of (K0.25Na0.75)NbO3 single crystals under bipolar electric fields have been performed for both pseudocubic (110) and (001) orientations using polarized light microscopy and X-ray diffraction. The macroscopic symmetry was identified to be a monoclinic C type phase with the spontaneous polarization direction close to ＜054＞. The electric field-driven domain morphology and evolution model were also presented. It was found that, under an antiparallel electric field, the approximately 180° domain switching process in a pseudocubic (101) sample consists of three steps: two ~60° domain switching and a ~90° domain switching, and the ~90° domain switching process in the pseudocubic (001) sample is composed of two ~60° switching steps. [ABSTRACT FROM AUTHOR]

The Dadu River Basin (DRB) is an important economic corridor on the Chuanxi Plateau. The DRB is located in the highly changeable terrain of the eastern Qinghai-Tibet Plateau and is often threatened by debris flows. To mitigate the damage of debris flow disasters to the construction and operation of large infrastructures such as railways, roads and hydropower stations in the DRB, it is necessary to evaluate debris flow susceptibility. The connectivity of potential material sources (CPMS), which proxies the possibility of potential material transfer from the source to the outlet, was calculated using an improved index of connectivity, excess topography and brittle fracture index to identify and quantify debris flow susceptibility. The results show that the IC and the gully scale have a Logartihmic function in the DRB, in which IC decreases as the catchment area increases. In 3967 gullies of the Dadu River and its tributaries, the total connectivity of potential material sources (TCPMS) could be used to distinguish between debris flow gullies and non-debris flow gullies (AUC = 0.748). The TCPMS and average connectivity of potential material sources (ACPMS) were used to classify the scale and activity intensity of the 2398 debris flow gullies into four levels. The moderate- and high-activity intensity and large- and extra large-scale debris flows are mainly distributed in Danba, Luding and Kangding. The results of this study provide reference and evidence for the identification and evaluation of debris flow susceptibility. • A new method for assessing debris flow susceptibility based on potential material sources and sediment connectivity. • The quantitative relationship between the scale of debris flow and conditioning factors. • The contribution of excess topography was considered. [ABSTRACT FROM AUTHOR]

Perovskite oxides with luminescent ions hold great promise in optoelectronic devices because of their outstanding thermal stabilities and electro-optic performance. As one typical perovskite upconversion (UC) host material, lead-free potassium sodium niobate ((K, Na)NbO3/(KxNa1-x)NbO3 or KNN) has attracted much attention in recent years. In the present work, a novel routine was developed to tune the upconversion photoluminescence (UC PL) performance by controlling the oxygen vacancy concentration in the KNN matrix, based on the 0.1% Er3+-doped KNN (Er-KNN) single crystals grown for the first time. UC PL properties, conductivity and defect chemistry of the single crystals were systematically investigated. The UC PL intensity of the as-grown Er-KNN material could be enhanced by 20 times after oxygen atmosphere annealing at 800 °C and fully quenched after vacuum annealing. What's more, by annealing under an oxygen atmosphere and vacuum, the conductivity of the Er-KNN sample was successfully tuned for more than 8 orders of magnitude. The super-wide range tunability of UC PL performance and conductivity could be explained by oxygen vacancies which gave rise to Nb5+-Nb4+ valence alternation. Because of the modulated photoluminescence properties and conductivity, our grown Er-KNN single crystals have great potential for use in multifunctional devices.

Primary hypertrophic osteoarthropathy (PHO) is a rare familial disorder with reduced penetrance for females. The genetic mutations associated with PHO have been identified in HPGD and SLCO2A1 which involved in prostaglandin E2 metabolism. Here we report 5 PHO patients from 4 non-consanguineous families. Two heterozygous mutations in solute carrier organic anion transporter family member 2A1 (SLCO2A1) were identified in two brothers by whole-exome sequencing. Three heterozygous mutations and 1 homozygous mutation were identified in other 3 PHO families by Sanger sequencing. However, there was no mutation in HPGD. These findings confirmed that homozygous or compound heterozygous mutations of SLCO2A1 were the pathogenic cause of PHO. A female individual shared the same mutations in SLCO2A1 with her PHO brother but did not have any typical PHO symptoms. The influence of sex hormones on the pathogenesis of PHO and its implication were discussed.

Objective: We analyzed a 6-year methadone maintenance treatment (MMT) retention rate in 8 MMT clinics in Xi'an and the factors that influenced the retention rate., Methods: We conducted a 6-year retrospective dynamic cohort study of 5849 eligible patients from 2006 to 2011. Participants were serially enrolled on the basis of opioid addiction, age, residence status, and civil capacity. Cumulative retention in treatment was calculated using survival analyses (life tables) on the basis of the number of days in MMT. We also used the Cox proportional hazard regression model to analyze the factors that may influence treatment retention., Results: The MMT retention varied from a less than 1 month to a maximum of 71.2 months; the average dose was 48.76 ± 17.03 mg/d. The cumulative retention for 12, 24, 36, 48, 60, and 72 months after MMT initiation were 0.87, 0.76, 0.66, 0.57, 0.49, and 0.43, respectively. The MMT retention rate was significantly associated with factors that included the particular clinic for MMT, the year when the subject initiated MMT, average daily dose, hidden drug use, sex, age, length of drug abuse history, needle sharing, living arrangements, and employment status., Conclusions: The 6-year retention rates for MMT in the 8 clinics in Xi'an were higher than those reported in other studies of other clinics. High therapeutic doses (>60 mg/d) could reduce the risk of patients withdrawing from treatment. Retention rates were relatively high in cohorts who were elderly, living with family, employed, or drug users, especially those with a long history of drug abuse.