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A 1200-V rated CoolSiC Trench MOSFET structure has excellent overall electrical characteristics due to its unique asymmetric structure. However, it is sensitive to space heavy ion radiation. In this study, heavy ion irradiation experiments were conducted on 1.2 kV CoolSiC Trench MOSFET devices to calibrate the simulation structure model and critical failure conditions. The 2-D numerical simulator SILVACO TCAD was used to investigate the single event burnout (SEB) hardening method for the 1.2 kV-rated CoolSiC Trench MOSFET under high linear energy transfer (LET) values. The simulation results show that the improved CoolSiC Trench MOSFET structure can effectively enhance the SEB capability of the device without sacrificing its excellent overall electrical characteristics compared to the traditional CoolSiC Trench MOSFET. At 360 V voltage and 0.5 pC/ $\mu $ m LET value, the highest temperature is reduced from 3097 to 1502 K, and the lowest burnout threshold is increased by 200 V in the improved structure while maintaining almost unchanged characteristics at other locations.

Background: Bile duct leaks (BDLs) are serious complications that occurs after hepatobiliary surgery and trauma, leading to rapid clinical deterioration. Endoscopic retrograde cholangiopancreatography (ERCP) is the first-line treatment for BDLs, but it is not clear which patients will respond to this therapy and which patients will require additional surgical intervention. The aim of our study was to explore the predictors of successful ERCP for BDLs. Methods: A retrospective analysis was conducted using data from six centers' databases. All consecutive patients who were clinically confirmed as BDLs were included in the study. Collected data were demographics, disease severity, and ERCP procedure characteristics. Univariate and multivariate analysis were used to select independent predictive factors that affect the outcome of ERCP for BDLs, and a nomogram was established. Calibration and ROC curves were used to evaluate the models. Results: Four hundred and forty-eight consecutive patients were clinically confirmed as BDLs and 347 were excluded. In the 101 patients included patients, clinical success was achieved in 78 patients (77.2%). In logistic multivariable regression, two independent factors were negatively associated with the success of ERCP: SIRS (OR, 0.183; 95% CI 0.039–0.864; P= 0.032) and high-grade leak (OR 0.073; 95% CI 0.010–0.539; P= 0.010). Two independent factors were positively associated with the success of ERCP: leak-bridging drainage (OR 4.792; 95% CI 1.08–21.21; P= 0.039) and cystic duct leak (OR 6.193; 95% CI 1.03–37.17; P= 0.046). The prediction model with these four factors was evaluated using a receiver-operating characteristic (ROC) curve, which demonstrated an area under the curve of 0.9351. The calibration curve showed that the model had good predictive accuracy. Conclusion: Leak-bridging drainage and cystic duct leak are positive predictors for the success of ERCP, while SIRS and high-grade leak are negative predictors. This prediction model with nomogram has good predictive ability and practical clinical value, and may be helpful in clinical decision-making and prognostication. Graphical abstract:

A facile method was proposed to prepare stretchable silver-based composite coatings with excellent conductivity and stability for flexible electronics. Silver coating was firstly deposited on thermoplastic polyurethane (TPU) elastomer rubber surface via two-component spraying technique, then the superhydrophobic surface was obtained by one-step electrodeposition of cerium compounds (CeM) and graphene nanosheets (GNS) to produce Ag/CeM/GNS composite coatings. The obtained Ag/CeM/GNS composite coatings maintained high conductivity after experiencing bending cycles and stretching cycles. Furthermore, the as-prepared Ag/CeM/GNS composite coatings showed excellent self-cleaning and anti-fouling properties, and the corrosion resistance has improved significantly compared to the original Ag coating. In addition, the Ag/CeM/GNS composite coatings could drive the circuit normally in the states of tensile, bending and twisting deformation, showing excellent mechanical stability and applicability. As a result, it is believed that the prepared Ag/CeM/GNS composite coatings with excellent conductivity and stability have promising applications for flexible electronics in harsh conditions.

Accelerating the experimental cycle for new materials development is vital for addressing the grand energy challenges of the 21stcentury. We fabricate and characterize 75 unique perovskite-inspired compositions within a 2-month period, with 87% exhibiting band gaps between 1.2 and 2.4 eV, which are of interest for energy-harvesting applications. We utilize a fully connected deep neural network to classify compounds based on experimental X-ray diffraction data into 0D, 2D, and 3D structures, more than 10 times faster than human analysis and with 90% accuracy. We validate our methods using lead-halide perovskites and extend the application to lead-free compositions. The wider synthesis window and faster cycle of learning enables the realization of a multi-site lead-free alloy series, Cs3(Bi1-xSbx)2(I1-xBrx)9. We reveal the non-linear band-gap behavior and transition in dimensionality upon simultaneous alloying on the B-site and X-site of Cs3Bi2I9with Sb and Br.

In this work, the photonic band gap (PBG) structure in a one-dimensional ferroelectric photonic crystal (PC) is theoretically investigated. We consider a PC, air/(AB)^N/air, in which layer A is a dielectric of MgO and layer B is taken to be a ferroelectric of Ba_0.55Sr_0.45TiO_3 (BSTO). With an extremely high value in the dielectric constant in BSTO, the calculated photonic band structure at microwave frequencies exhibits some interesting features that are significantly different from those in a usual dielectric–dielectric PC. First, the photonic transmission band consists of multiple and nearly discrete transmission peaks. Second, the calculated bandwidth of the PBG is nearly unchanged as the angle of incidence varies in the TE wave. The bandwidth will slightly reduce for the TM mode. Thus, a wide omnidirectional PBG can be obtained. Additionally, the effect of the thickness of the ferroelectric layer on the PBG is much more pronounced compared to the dielectric layer thickness. That is, the increase of ferroelectric thickness can significantly decrease the PBG bandwidth.

So far, the research about sediment ablation characteristic of the Yellow River is very insufficiency. For preventing and alleviating sediment ablation of the Yellow River stations by more scientific methods, it is very necessary to research ablation characteristic of hydraulic turbine systematically. The ablation characteristic of hydraulic turbine has direct relation with sediment size distribution. By research ablation of hydraulic turbine material under different sediment size distributions, the common rules are summarized between material ablation and sediment size distribution, and the key data and critical parameters are found out, which provides evidence for sediment ablation defend of hydraulic turbine.

The author analyzed the working characteristics of special turbine for cooling tower basing on the difference between the special turbine and the conventional hydraulic turbine. This paper points out that the special turbine works in a pressure water system and has typical ultra-low specific speed characteristic. These characteristics determine the type and parameters selection of the special turbine. Based on the theory the author has designed some special turbines in many projects in China. The practical operation shows that the turbines have high energy conversion efficiency and are steady in operation, with fairly good matching of the fans.