Search

The active site density, intrinsic activity, and supporting substrate of cobalt phosphide catalysts are vital to their performance in alkaline water electrolysis. In this work, a CoP/Co2P loaded on cellulose nanofiber-derived carbon aerogels (CP/CCAs) bifunctional electrocatalyst with a three-dimensional network and heterostructure is illustrated through sequential facile hydrothermal, freeze-drying, and phosphorylation processes. The three-dimensional network of carbon aerogels derived from cellulose nanofibers reveals a specific surface area of 183.41 m2/g, greatly enriching the active sites and facilitating the electron and mass transportation. Besides, interactions between CoP/Co2P with a heterogeneous structure and carbon aerogels modulate the electronic structure to enhance the intrinsic activity of the catalysts. Benefiting from these advantages, CP/CCAs-2 demonstrates a superior oxygen evolution reaction activity (η10 mA cm–2= 277 mV) over the benchmark RuO2and a moderate hydrogen evolution reaction performance (η10 mA cm–2= 63 mV). Density functional theory calculations further reveal that the coupling of CoP/Co2P and cellulose-derived carbon aerogels promotes the water adsorption and activates the H–O bond. As a result, the alkaline electrolyzer assembled with CP/CCAs-2 both as a cathode and an anode shows a low cell voltage of 1.59 V at a current density of 10 mA cm–2and good stability. This work provides a strategy for phosphide electrocatalysts composited with green carbon carriers for overall water splitting.

In this communication, a novel pattern and beamwidth reconfigurable cylindrical dielectric resonator antenna (CDRA) is proposed. The pattern reconfigurable structure is achieved by a pair of 3-D-printed arc-shaped parasitic metal panels, which are capable of high-gain beam scanning with ±24° in the H-plane and ±18° in the E-plane radiation, respectively, without the electrical controlling components. Moreover, by arranging the arc-shaped parasitic metal panels symmetrically, the half-power beamwidth (HPBW) of the antenna can be adjusted from 48° to 79°. The proposed DRA utilizes a stacked multilayer dielectric substrate structure to excite the HEM $_{12\sigma }$ higher-order mode which improves the gain performance. Finally, the antenna achieved the maximum gain of 10.6 dBi in the operating bandwidth. The pattern reconfiguration through mechanical control avoids the extra insertion loss that could result from PIN diodes and allows for a high overlapped bandwidth in different radiation patterns. The measured overlap-operating frequency band and maximum gain of the antenna with different radiation states are 2.17–2.72 GHz (fractional bandwidth (FBW) of 22.49%) and 10.42 dBi, respectively. These values are well suited for the 2.4 GHz ISM band applications.

In this letter, a novel silicon-on-insulator (SOI) lateral Hall device (LHD) with deep trench fingers (DTFs) is proposed. The DTFs in magnetic-sensitive well mitigate the short-circuit effect and make current-related sensitivity (S $_{\text {I}}\text {)}$ insensitive to the signal electrode size. The SI of the proposed LHD is over 1000V/AT, the input resistance (R $_{\text {in}}\text {)}$ is around 40.5k $\Omega $ and offset is lower than 2.5mV. With four-phase spinning current method, the residual offset is reduced to $17~\mu $ V and the proposed LHD has high linearity output at a magnetic field from 10mT to 300mT. In addition, the proposed LHD presents high stability across temperature ranging from 25°C to 225°C.

The failure mechanism of single-event burnout (SEB) in 4H-SiC inverter is studied by experiments and simulations. The most sensitive location for heavy ions striking in the 4H-SiC inverter circuit has been identified by pulsed laser experiments. Experimental results demonstrate that the maximum linear energy transfer (LET) value that the 4H-SiC inverter circuit can withstand is exceeding 64.07 MeV $\cdot $ cm2/mg but not surpassing 92.25 MeV $\cdot $ cm2/mg. Sentaurus TCAD is utilized to reveal the failure mechanism. The incident heavy-ion radiation triggers the activation of parasitic p-n-p and n-p-n transistors, resulting in a latch-up phenomenon within the circuit, consequently leading to the circuit burnout. The revealed failure mechanism gives a guidance for further hardened circuits design.

• The nanocrystalline coatings were designed and prepared by magnetron sputtering. • In-situ Al 2 O 3 nanoparticles were found in the SNO coatings. • The diffusion of Ta throughout the coating is retarded by reactive sputtering with o. • The oxidation resistance of the SNO coatings is significantly improved. The presence of excess Ta in high-temperature protective coatings can compromise the integrity of the Al 2 O 3 scale on the surface, which has a negative impact on the oxidation behavior and reduces the service life. The effects of oxygen doping on the isothermal oxidation of three sputtered nanocrystalline coatings were investigated at 1100 °C. The results indicated that oxygen doping inhibited the diffusion of Ta from the coating to the oxide scale, which was primarily attributed to the preferential oxidation of the Al in the coating. However, excess oxygen doping decreased the amount of Al available for the formation of the Al 2 O 3 scale on the coating, thus reducing the inhibitory effect on Ta oxidation. Moreover, doping with excess O caused spalling of the oxide scale. Therefore, the right balance in O doping is crucial for suppressing Ta oxidation while maintaining the integrity of the oxide scale. [Display omitted] [ABSTRACT FROM AUTHOR]

The ethylene and vinyl acetate (VA) mixture must be compressed to a high pressure of over 100 MPa in a hyper-compressor system to initiate the polymerization. This paper presents a numerical and experimental investigation into the effects of VA concentration on the performance of a hyper-compressor. To this end, an equation of state in the form of Helmholtz free energy was developed to calculate the real thermodynamic properties of VA–ethylene mixture. The average absolute deviations of density and compressibility factor for VA-ethylene compared with experimental values were 1.82% and 1.46%, respectively. Additionally, a three-dimensional (3D) computational fluid dynamics (CFD) model was constructed considering real-fluid thermodynamics, incorporating the motion of the central valve and upstream and downstream pressure pulsations. The predicted p−Vdiagram and pressure pulsation were compared with experimental data to validate the accuracy of the 3D-CFD model. The results demonstrated that a higher VA weight fraction results in a shorter expansion and compression phase; higher indicated power, suction, and discharge losses; and greater pressure fluctuation. The increment of power loss during the discharge process accounted for 73.27% of the indicated power growth 35.96 kW as the VA weight fraction increased from 0% to 40%. The increment of pressure pulsation in the suction and discharge pipe were mainly attributed to high-frequency pulsations above 10 orders and low-frequency pulsations below 10 orders, respectively.

• Breakaway oxidation of CB2 occurred in O 2 +H 2 O mixture at 630 °C. • An inorganic potassium silicate coating was prepared and cured at room temperature. • Leucite (KAlSi 2 O 6) formed in coating due to reaction of NiCrAlY with K 2 SiO 3 at 630 °C. • The coating exhibited excellent corrosion resistance in O 2 /O 2 +H 2 O mixture at 630 °C. An inorganic potassium silicate coating with pigments of alumina, aluminum phosphate, NiCrAlY and copper chromite black was prepared on CB2 stainless steel. Oxidation behavior in either ambient air or O 2 +H 2 O mixture at 630 °C for 2000 h was comparatively studied, and the coating exhibited excellent resistance under both test conditions. The water vapor considerably accelerated the oxidation of the uncoated CB2 steel, as the hydroxide, the main constituent of the coating, had a negligible evaporation rate at test temperature, while it had a limited effect on the coated sample. Meanwhile, the existence of coating may prolong or eliminate the incubation period in the O 2 +H 2 O mixture at 630 °C. After oxidation, the coating matrix is in an amorphous state and fillers as alumina and copper chromite black are stable in the coating. Leucite (KAlSi 2 O 6) formed by Al from NiCrAlY and potassium silicate in the coatings was detected after tests either in O 2 or O 2 +H 2 O mixture. [Display omitted] [ABSTRACT FROM AUTHOR]

Rechargeable aqueous zinc metal batteries (RAZMBs) have received extensive attention for large-scale energy storage systems due to the merits of Zn anodes, including moderate volumetric and gravimetric energy density, low redox potential, abundant reserve, low cost and impressive intrinsic safety. However, Zn anodes suffer from a series of adverse reactions (dendrite growth, hydrogen evolution, and surface passivation) resulting in low Coulombic efficiency, large polarization, and unsatisfied cycling performance, which inevitably hinder the wide application of RAZMBs. To address the above issues, cellulose-based materials are widely used for Zn anode protection because of their unique physical and chemical properties and other advantages such as biocompatibility, non-toxicity, degradability and easy extraction. In order to better understand the current progress in cellulose-based materials for the Zn anode protection, we have classified and summarized the relevant literatures. In this review, we summarize and elaborate the causes of poor reversibility for Zn anodes, including dendrite formation, hydrogen evolution, and surface passivation. Subsequently, the effective strategies (anode interfacial engineering, gel electrolyte optimization, and separator modification) of cellulose-based materials toward stabilizing Zn anodes are overviewed. In the end, the existing challenges and prospects of cellulose-based materials in Zn anode protection are summarized to shed light on future work.

This article proposes an aging reliability compact model with high accuracy to simulate trap effects after long-term aging in power Gallium Nitride (GaN) based high electron mobility transistors (HEMTs). Dynamic on-state resistance $(R_{\mathrm{ on,dy}})$ caused by trap effects is taken as an example to deliver the aging reliability modeling concepts and flows. Based on the mechanism of trap effects and accelerated-stress experiments, the variation model of electron mobility has been established, so that the degradation of $R_{\mathrm{ on,dy}}$ after aging can be predicted. The structure of the advanced SPICE model for GaN HEMT (ASM-HEMT) is modified to integrate the mobility variation model into SPICE for convenient usage. In addition, the accuracy of the proposed model has been verified, and the RMSE value between measured data and simulated data under long-term high temperature reverse bias stress conditions is only 1.68%, thus the hazard of the power system caused by traps can be discovered and avoided in advance.

This study aimed to investigate the impact of building planes on the microstructure and corrosion behaviors of 316L stainless steel (SS) manufactured using selective laser melting (SLM) when subjected to a 0.1 M HCl solution. The investigation of material corrosion behavior involved the utilization of a wide array of surface characterization techniques, as well as various electrochemical measurements. The findings were subjected to a comparison with those obtained from a commercially rolled 316L SS (R 316L SS). The analysis revealed that the XZ and YZ planes displayed a distinctive fish scale melt pool structure, while the XY plane exhibited a columnar melt pool structure. The densities of the low-angle grain boundaries for different building planes were observed as YZ < XY < XZ. SLM 316L SS showing a broader passivation region and a higher breakdown potential compared to the commercially available R 316L SS, especially the XZ and XY planes. Meanwhile, the passive film on the XZ plane was the more compact and had a lower carrier density. The observed factors contributing to these findings could be attributed to the SLM sample containing an increased proportion of O2−/OH−and Cr2O3in the passive film. This resulted in the formation of a thick and dense passive film, which is particularly evident on the XY and XZ planes. In addition, it was observed that the nucleation mechanism of the passive films remained unchanged following the SLM process.

AbstractDisplacement prediction is a direct and effective method for mitigating geohazards. Due to the influence of rainfall and reservoir water level variations, landslides often display step-like deformations with an increasing trend and periodic fluctuation, indicating long-term memory in displacement time series. Traditional data-driven methods are mostly suitable for short-term prediction, and extra data processing is applied to solve this problem. This paper proposes a novel deep learning-based displacement prediction method using long short-term memory (LSTM) networks. Based on open-source frameworks for deep learning, namely, Keras and TensorFlow, a detailed implementation of displacement prediction is proposed and illustrated. The Baishuihe landslide, a typical landslide with long-term monitoring, is taken as a case study, and both single-factor and multi-factor predictions are performed. The results indicate that multi-factor prediction can reduce overfitting and improve accuracy. Compared with the existing method, the multi-factor deep-learning model displays better performance. This study indicates that the LSTM-based deep-learning model is suitable and convenient for displacement prediction and has broad prospects in safety monitoring of water-induced landslides.

AbstractThis paper explores the deformation behaviour of 1#toppling rock slope, located on the right bank of the Lancang River upstream of Huangdeng Hydropower Station in China. Field monitoring data show that the surficial and deep displacements of the toppling rock slope increase greatly during the second stage of the impoundment period. The deformation of the toppling rock slope in the lower part is generally larger than that in the higher part, and the displacement near the dam side is larger than that farther from dam. Furthermore, the horizontal deep displacement decreases with increasing depth of the slope. Based on the measured displacements of the toppling rock slope, the grey relational analysis (GRA) method is used to explore the correlations between the slope displacement rate and the relevant influencing factors, including rainfall, water level fluctuation, time and air temperature. The results show that the main control factors influencing the slope displacement rate are the water level fluctuation followed by rainfall. The findings may suggest that the 1#toppling rock slope has the potential of hydrodynamic instability, and the water level fluctuation caused by the reservoir operation should be fully concerned to avoid the instability of the toppling rock slope.

AbstractDuring the operation period of the high arch dam in some canyon area, the valley deformation is obvious under complex geological environment. Several possible factors may influence this phenomenon. In this article, influencing factors are considered from the aspects of precipitation, temperature, reservoir water level elevation and the rate of reservoir water level variation. Two machine learning methods are employed to investigate these factors, namely, Lasso and Random forest, and serve as a basis for further studying the formation mechanism of valley deformation. Using the Lasso method, four variations are selected from 74 variations which are representative of precipitation and temperature, e.g. daily precipitation, 10-day antecedent precipitation, 10-day maximum rainfall difference, and 25-day maximum temperature difference. Combined with the reservoir water level elevation and the rate of reservoir water level variation, these six key factors are analyzed by the Random forest method so to carry out a quantitative analysis of their influence on valley deformation. Results show that the valley deformation is mainly affected by the rate of reservoir water level variation and the reservoir water level elevation among the selected factors, indicating valley deformation might be induced with hydrodynamic force.

AbstractMany models have been developed for landslide displacement prediction, but owing to complex landslide-formation mechanisms and landslide-inducing factors, such models have different prediction accuracies. Thus, landslide displacement prediction remains a popular but difficult topic of research. In this paper, a landslide prediction model is proposed by combining extreme learning machine (ELM) and random search support vector regression (RS-SVR) sub-models. Particularly, the combined model decomposed accumulative landslide displacement into two terms, trend and periodic displacements, using a time series model, and simulated and predicted the two terms using the ELM and RS-SVR sub-models, respectively. The predicted trend and periodic terms are then summed to obtain the total displacement. The ELM and RS-SVR sub-models are applied to predict the deformation of Baishuihe landslide in the Three Gorges Reservoir Area (TGRA) as an example. The results showed that the model effectively improved the accuracy, stability, and scope of application of landslide displacement prediction, thus providing a new method for landslide displacement prediction.

This letter introduces a new physics-based SPICE modeling method for the dynamic on-state resistance (Ron,dy) of gallium nitride based p-type gate power high electron mobility transistors (p-GaN HEMTs). To describe the continuous variations of Ron,dy, a time-resolved electron mobility variation (Δμeff) model is proposed. Physical parameters including activation energy and voltage acceleration factor of traps in p-GaN HEMTs are extracted as the model parameters. Then, to achieve the goal of simulating Ron,dy, the proposed Δμeff model is incorporated into the surface potential based advanced SPICE model for GaN HEMT. Simulative results prove the proposed models can predict the R on,dy induced power loss.

• The O dopped nanocrystalline coating is prepared by reactive magnetron sputtering. • The doping of O significantly improves the oxidation resistance of the coating. • The surface rumpling behaviors on coatings is retarded by oxygen. Surface rumpling is detrimental to high temperature protective coatings as it shortens their lifetime and leads to adhesion losses and unexpected corrosion degradation. The driving force and mass transport mechanism behind of rumpling remains to be clarified. In the present investigation, we subjected two types of nanocrystalline coating systems to avoid the influence of interdiffusion on rumpling study. One group was an ordinary nanocrystalline coating, and the other group was designed and prepared with trace oxygen by reactive magnetron sputtering. Systematic cyclic oxidation test at 1100 °C was also carried out. Results show the ordinary nanocrystalline coating oxidized rapidly, which leads to the fast consumption of Al and the acceleration of phase transition in the coating. Meanwhile, severe surface rumpling is observed due to the stress release of nanocrystals through plastic deformation. Besides, the reactive doping of oxygen can significantly reduce the consumption process of Al in nanocrystalline coating. The rumpling is controlled due to the improvement of coefficient of thermal expansion and Young's modulus of the coating. Thereafter, the cyclic oxidation resistance is improved. [ABSTRACT FROM AUTHOR]

This study employs advanced electrochemical and surface characterization techniques to investigate the impact of electrochemical hydrogen charging on the corrosion behavior and surface film of the Ti-6Al-4V alloy. The findings revealed the formation of γ-TiH and δ-TiH2hydrides in the alloy after hydrogen charging. Prolonging hydrogen charging resulted in more significant degradation of the alloy microstructure, leading to deteriorated protectiveness of the surface film. This trend was further confirmed by the electrochemical measurements, which showed that the corrosion resistance of the alloy progressively worsened as the hydrogen charging time was increased. Consequently, this work provides valuable insights into the mechanisms underlying the corrosion of Ti-6Al-4V alloy under hydrogen charging conditions.

• Effect of isothermal aging on pitting of high-nitrogen stainless steel is studied. • Aging time had minor influence on corrosion potential and corrosion current density, but a profound decrease of the pitting potential. • The fraction of Cr 2 O 3 in the passive film decreased with aging time. The effect of aging treatment on the microstructure and corrosion behavior of a Fe-18Cr-15Mn-0.66N high-nitrogen stainless steel (HNSS) in 3.5 wt.% NaCl solution was investigated using a series of electrochemical tests, scanning electronic microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results showed that the aging treatment led to the precipitation of Cr 2 N particles along the grain boundaries and their morphologies changed from dispersive particles to continuous network as the aging time increased up to 60 min. Aging time had minor effects on the corrosion potential and corrosion current density, but resulted in the sharp decrease in the pitting corrosion potential. The passive film behaved as a n-type semiconductor, and the donor density of the passive film increased with the aging time. Meanwhile, the fraction of stable oxide (Cr 2 O 3) in the passive film decreased with the aging time. It demonstrates that the aging treatment deteriorated the protectiveness of the passive film, hence weakened the corrosion resistance of HNSS. [ABSTRACT FROM AUTHOR]

Rechargeable magnesium batteries (RMBs) are considered as one of the most promising next-generation secondary batteries due to their low cost, safety, dendrite-free nature, as well as high volumetric energy density. However, the lack of suitable cathode material and electrolyte is the greatest challenge facing practical RMBs. Herein, a hybrid electrolyte MgCl2/AlCl3/Mg(TFSI)2(MACT) in dimethyl ether (DME) is developed and exhibits excellent electrochemical performance. The high ionic conductivity (6.82 mS cm–1) and unique solvation structure of [Mg2(μ-Cl)2(DME)4]2+promote the fast Mg kinetics and favorable thermodynamics in hybrid Mg salts and DME electrolyte, accelerating mass transport and the charge transfer process. Therefore, the great rate capability can be realized both in symmetric Mg/Mg cell and in CuS/Mg full cell.

Co‐simulation combined with Full‐wave 3D and circuit elements is used to investigate ESD effects on signal transferring of a simplified smart phone device. A square wave with amplitude of 1.8V is applied to an address line transferring from CPU to DDR cache. Both the signal frequency and the position at the address line are simulated on signal transferring. The simulation results indicate that ESD event actually influences the signal transferring which may lead to error data transferring.

Quantum dot color conversion as a display form, it can greatly improve the display color gamut of OLED, and can also be used as an effective colorization technology solution for MicroLED. Here we design the quantum dot pixel structure, carry out the preparation and verification of big‐thickness BM, quantum dot pixel and Bragg reflector for prepare quantum dot color conversion devices initially. After evaluation, we give corresponding suggestions for the application research of later quantum dot color conversion.

Two-stage cascade architecture is widely used in the modular power supply applications. In order to reduce the additional component number caused by the cascading structure, the power switch integration technique is proposed in numerous literature studies. However, the power switch integration leads to both the efficiency degradation and the abnormal gain of the stage employed. In this article, the four-switch noninverting buck–boost converter is merged with the LLC resonant converter. The proposed integration method has no awful influence on the efficiency and the gain of the LLC stage. Meanwhile, the soft switch capability of the integrated bridge can be enhanced due to the accumulation of the two currents of the buck–boost stage and the LLC stage during dead time. Moreover, the current of the two-stage will commutate to cancel out with each other during the conduction period, reducing the conduction loss and improving the overall efficiency. The benefits of the integrated bridge make the proposed converter appropriate for the high-frequency and high-efficiency application. Finally, a 720-W 1-MHz prototype is built to prove the performance of the proposed converter. The prototype achieves a peak efficiency of 96.4% and the input voltage range of 250–420 V.

In this paper, a simple device under electrostatic discharge (ESD)event is considered. This work presents a simple experimental and simulated setup to measure ESD‐induced voltage to trace on a printed circuit board (PCB) when ESD current is injected directly onto the lumped element. Based on an ESD immunity test platform and ESD full‐wave model, the waveform of coupling voltage, which induced on a PCB, are measured at different discharging position. The voltage waveform of resistor on PCB with chip and without chip are compared to analyze the difference in two cases. The paper proposes a method that compares the measured results of experiment with simulation of full‐wave model. It is found that the results of simulation and experiment is in good match on the whole.

M CrAlY (M =Ni and/or Co) overlay coating is widely used as a protective coating against high temperature oxidation and corrosion. However, due to its big difference in chemical composition with the underlying superalloy, elements interdiffusion occurs inevitably. One of the direct results is the formation of interdiffusion zone (IDZ) and secondary reaction zone (SRZ) with a high density of fine topological closed-packed phases (TCPs), weakening dramatically the mechanical properties of the alloy substrate. It is by now the main problem of modern high-temperature metallic coatings, but there are still hardly any reports studying the formation, growth and transformation of IDZ and SRZ in deep, as well as the precipitation of TCPs. In this work, a typical NiCrAlY coating is deposited by arc ion plating on a single-crystal superalloy N5. Elements interdiffusion between them and its relationship on microstructure were clarified. Cr rather than Al from the coating diffuses into the alloy at high temperatures and segregates immediately beneath their interface, contributing largely to the formation of IDZ. Simultaneously, diffusion of Ni from the deep alloy to IDZ leads to the formation and continuous expansion of SRZ. [ABSTRACT FROM AUTHOR]

Stepless capacity regulation through delayed closure of suction valves plays an important role in energy conservation for reciprocating compressors. Serious gas pulsation usually occurs with a suction valve unloader, and its analysis and suppression is a challenge owing to the varied components of the pulsation excitation under different conditions. In this study, a fast algorithm was proposed to calculate the gas pulsation of a compressor system with stepless capacity regulation and was further incorporated into the frequency-domain modeling of the gas pulsation. A test rig was constructed, and the model was experimentally verified. The dynamic pressure at positions in the suction and discharge valve chambers was measured, as the compressor capacity was varied by changing the closing time of the suction valves. The experimental data were compared with the simulated results and indicated a good agreement. The results showed that the suction valve unloader had a negative impact on the gas pulsation in the suction pipeline system. The pressure pulsation of the main excitation frequency increased in the suction pipeline system and decreased in the discharge pipeline, as the opening time of the suction valve increased.

The subjective brightness is determined by not only the display screen luminance but also the light surrounding the display. A metric for space brightness named “Feu” is adopted to consider the effect of luminance distribution. The relation between the pupil diameter and the space brightness is applied to obtain the subjective brightness. The measured subjective brightness is obtained both for direct‐view display and augmented reality (AR) display. The results indicate that the measured subjective brightness is much closer to the perceived result. The subjective brightness increases along with the increase of the screen luminance under the same ambient illuminance. While under the same screen luminance, the subjective brightness decreases with the increase of the ambient illuminance in most cases. The subjective brightness is determined by not only the display screen luminance but also the light surrounding the display. A LCD display system and an AR display system under different ambient illuminance are observed and measured. The results indicate that the measured subjective brightness is much closer to the perceived result.

Gratings are widely used as coupling parts in a waveguide display system for achieving a much lighter and more compact system, but their diffraction efficiency needs to be improved. Two combined gratings for integrating a subwavelength binary grating and volume holographic grating (VHG) are applied as incoupler and outcoupler of a holographic waveguide display system. Two basic design rules are put forward to guarantee the maximum diffraction energy guided into the waveguide and finally coupled out to enter into the user’s eyes: one is the grating vector matching rule, the other is the refractive index matching rule on the interface of the binary grating and the VHG. The finite element method is used to simulate the couple-in parts and the whole waveguide display system. The combined grating with the metal binary grating is different from that with a dielectric binary grating for achieving higher diffraction efficiency and an additional second peak in the diffraction efficiency curve varied with the relative position between the binary grating and the VHG. The simulation results indicate that a VHG+Ag combined grating can obtain much higher diffraction efficiency compared to gold, aluminum, and other dielectric materials. In addition, several factors such as the Bragg wavelength, the index modulation of VHG, binary grating thickness, and the filling factor of the binary grating are discussed for the VHG+Ag combined grating. Moreover, a higher diffraction efficiency in the holographic waveguide system can be obtained by using VHG+Ag−VHG+Ag combined gratings as the incoupler and outcoupler.

The subjective brightness is determined by not only the display screen luminance but also the light surrounding the display. A metric for space brightness named “Feu” is adopted to consider the effect of luminance distribution. The relation between the pupil diameter and the space brightness is applied to obtain the subjective brightness. The measured subjective brightness is obtained both for direct‐view display and AR display. The results indicate that the measured subjective brightness is much closer to the perceived result. The subjective brightness increases along with the increase of the screen luminance at the same ambient illuminance. While at the same screen luminance, the subjective brightness decreases with the increase of the ambient illuminance in most cases.

Pancreatic pseudocyst (PPC) increases the risk of a poor prognosis in in patients with acute pancreatitis (AP). Currently, an efficient tool is not available for predicting the risk of PPC in patients with AP. Therefore, this research aimed to explore the risk factors associated with PPC secondary to AP and to develop a model based on clinical information for predicting PPC secondary to AP. This study included 400 patients with acute pancreatitis and pancreatic pseudocyst secondary to acute pancreatitis admitted to the emergency department and gastroenterology department of The First Affiliated Hospital of the University of Science and Technology of China from January 2019 to June 2022. Participants were divided into no PPCs (321 cases) and PPCs (79 cases). Independent factors of PPC secondary to AP were analyzed using univariate and multivariate logistic regression. The nomogram model was constructed based on multivariate logistic regression analyses, which included all risk factors, and evaluated using R. We enrolled 400 eligible patients and allocated 280 and 120 to the training and test sets, respectively. Clinical features, including severe pancreatitis history [odds ratio (OR) = 4.757; 95% confidence interval (CI): 1.758–12.871], diabetes mellitus (OR = 6.919; 95% CI: 2.084–22.967), history of biliary surgery (OR = 9.232; 95% CI: 3.022–28.203), hemoglobin (OR = 0.974; 95% CI: 0.955–0.994), albumin (OR = 0.888; 95% CI: 0.825–0.957), and body mass index (OR = 0.851; 95% CI: 0.753–0.962), were significantly associated with the incidence of PPC after AP in the training sets. Additionally, the individualized nomogram demonstrated good discrimination in the training and validation samples with good calibration, The area under the curve and 95% CI of the nomogram were 0.883 (0.839–0.927) in the training dataset and 0.839 (0.752–0.925) in the validation set. We developed a nomogram model of PPC secondary to AP using R Studio. This model has a good predictive value for PPC in patients with AP and can help improve clinical decision-making.

Electrochemical conversion reactions of metal oxides provide a new avenue to build high capacity anodes for sodium-ion batteries. However, the poor rate performance and cyclability of these conversion anodes remain a significant challenge for Na-ion battery applications because most of the conversion anodes suffer from sluggish kinetics and irreversible structural change during cycles. In this paper, we report an Fe2O3single crystallites/reduced graphene oxide composite (Fe2O3/rGO), where the Fe2O3single crystallites with a particle size of ∼300 nm were uniformly anchored on the rGO nanosheets, which provide a highly conductive framework to facilitate electron transport and a flexible matrix to buffer the volume change of the material during cycling. This Fe2O3/rGO composite anode shows a very high reversible capacity of 610 mAh g–1at 50 mA g–1, a high Coulombic efficiency of 71% at the first cycle, and a strong cyclability with 82% capacity retention after 100 cycles, suggesting a potential feasibility for sodium-ion batteries. More significantly, the present work clearly illustrates that an electrochemical conversion anode can be made with high capacity utilization, strong rate capability, and stable cyclability through appropriately tailoring the lattice structure, particle size, and electronic conduction channels for a simple transition-metal oxide, thus offering abundant selections for development of low-cost and high-performance Na-storage electrodes.

A new way was meticulously designed to utilize the localized surface plasmon resonance (LSPR) effect and the light scattering effect of silver nanoplate (Ag-nPl) and core–shell Ag@SiO2nanoparticles (Ag@SiO2-NPs) to enhance the photovoltaic performances of polymer solar cells (PSCs). To prevent direct contact between silver nanoparticles (Ag-NPs) and photoactive materials which will cause electrons quenching, bare Ag-nPl were spin-coated on indium tin oxide and silica capsulated Ag-NPs were incorporated to a PBDTTT-C-T:PC71BM active layer. As a result, the devices incorporated with Ag-nPl and Ag@SiO2-NPs showed great enhancements. With the dual effects of Ag-nPl and Ag@SiO2-NPs in devices, all wavelength sensitization in the visible range was realized; therefore, the power conversion efficiency (PCE) of PSCs showed a great enhancement of 14.0% to 8.46%, with an increased short-circuit current density of 17.23 mA·cm–2. The improved photovoltaic performances of the devices were ascribed to the LSPR effect and the light scattering effect of metallic nanoparticles. Apart from optical effects, the charge collection efficiency of PSCs was improved after the incorporation of Ag-nPl.

Volume holographic gratings are widely used as couplers in eyewear waveguide display systems, but they show a relative lower TM polarized energy compared to transverse-electric (TE) incidence. In this paper, we propose a novel holographic waveguide display system with a combined-grating as the in-coupler. When used as an in-coupler for a holographic waveguide display system, a subwavelength metal grating is designed onto the volume holographic grating to increase the total diffraction efficiency of the coupling gratings. Theoretical calculations show that this design increases the diffraction efficiency by 16.4% for TM polarization, 4.3% for TE mode, and 10.0% for unpolarized light, compared to a single volume holographic grating. Calculations also show that the use of this design as an in-coupler for a holographic waveguide system increases the luminance efficiency for these three modes by 26.8%, 9.0%, and 15.6%, respectively.

A new type of ac plasma display panel (PDP) with shadow mask (SM-PDP) is presented for its effective structures with lower cost. A two-dimensional self-consistent fluid model is used to analyse the discharge characteristics of the SM-PDP cell in a simplified driving scheme. The effects of the addressing time, the sustaining frequency, the duty ratio of the sustain voltage and the rise time of the voltage pulse on the discharge efficiency are investigated in this paper. The simulation results can help us optimize the driving scheme of SM-PDP.