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ObjectiveTo determine the subtypes and epidemiological characteristics of respiratory syncytial virus （RSV） in children with acute respiratory infection in Huzhou area.MethodsA total of 1 856 nasopharyngeal swabs were collected from child outpatients and inpatients in the First People’s Hospital of Huzhou from January 2017 to December 2019. RSV subtype A and B were detected by real-time fluorescence PCR. Clinical and demographic data of children were collected and analyzed.ResultsThe positive rate of RSV in the collected samples was determined to be 11.1% （206/1 856）， of which the positive rate of RSV-A was 6.6% （123/1 856） and that of RSV-B was 4.5% （83/1 856）. The positive rate of RSV in boys was significantly higher than that in girls （13.7% vs 8.3%，P

Aiming at the research blank of the reliability evaluation of high failure rate line replaceable unit(LRU) and the location of LRU fault component in the aviation maintenance, a reliability evaluation simulation model applicable for LRU “replacement maintenance” strategy is designed. The design principle and the actual methods as well as steps of each function module in the model are introduced in detail. Finally, the model is applied and analyzed to a common high failure rate LRU in a certain type of aircraft hydraulic system as an example, the result shows that the simulation model is practical and universally applicable to the reliability evaluation of LRU.

The valence and conduction band offsets at the interfaces between NiO/AlN, SiO2/AlN, Al2O3/AlN, and ITO/AlN heterointerfaces were determined via x-ray photoelectron spectroscopy using the standard Kraut technique. These represent systems that potentially would be used for p-n junctions, gate dielectrics, and improved Ohmic contacts to AlN, respectively. The band alignments at NiO/AlN interfaces are nested, type-I heterojunctions with a conduction band offset of −0.38 eV and a valence band offset of −1.89 eV. The SiO2/AlN interfaces are also nested gap, type-I alignment with a conduction band offset of 1.50 eV and a valence band offset of 0.63 eV. The Al2O3/AlN interfaces are type-II (staggered) heterojunctions with a conduction band offset of −0.47 eV and a valence band offset of 0.6 eV. Finally, the ITO/AlN interfaces are type-II (staggered) heterojunctions with conduction band offsets of −2.73 eV and valence band offsets of 0.06 eV. The use of a thin layer of ITO between a metal and the AlN is a potential approach for reducing contact resistance on power electronic devices, while SiO2 is an attractive candidate for surface passivation or gate dielectric formation on AlN. Given the band alignment of the Al2O3, it would only be useful as a passivation layer. Similarly, the use of NiO as a p-type layer to AlN does not have a favorable band alignment for efficient injection of holes into the AlN. [ABSTRACT FROM AUTHOR]

Strain plays an important role in the performance and reliability of AlGaN/GaN high electron mobility transistors (HEMTs). However, the impact of strain on the performance of proton irradiated GaN HEMTs is yet unknown. In this study, we investigated the effects of strain relaxation on the properties of proton irradiated AlGaN/GaN HEMTs. Controlled strain relief is achieved locally using the substrate micro-trench technique. The strain relieved devices experienced a relatively smaller increase of strain after 5 MeV proton irradiation at a fluence of 5 × 1014 cm−2 compared to the non-strain relieved devices, i.e., the pristine devices. After proton irradiation, both pristine and strain relieved devices demonstrate a reduction of drain saturation current (Ids,sat), maximum transconductance (Gm), carrier density (ns), and mobility (μn). Depending on the bias conditions the pristine devices exhibit up to 32% reduction of Ids,sat, 38% reduction of Gm, 15% reduction of ns, and 48% reduction of μn values. In contrast, the strain relieved devices show only up to 13% reduction of Ids,sat, 11% reduction of Gm, 9% reduction of ns, and 30% reduction of μn values. In addition, the locally strain relieved devices show smaller positive shift of threshold voltage compared to the pristine devices after proton irradiation. The less detrimental impact of proton irradiation on the transport properties of strain relieved devices could be attributed to reduced point defect density producing lower trap center densities, and evolution of lower operation related stresses due to lower initial residual strain. [ABSTRACT FROM AUTHOR]

Switching of vertical 6.1 kV/4A NiO/Ga2O3 rectifiers from voltages up to 1.45 kV showed reverse recovery times of 75 ns, current slew rate of 39.0 A/μs, and energy loss of ∼105 μW. These are the highest switching voltages reported for Ga2O3 rectifiers. To place the results in context, commercial 3.3 kV/5 A SiC merged PiN Schottky diodes showed reverse recovery times of 20 ns, current slew rate of 47.5 A/μs, and energy loss of ∼67 μW. The validity of comparing unpackaged experimental Ga2O3 diodes with commercial Si or SiC diodes without considering their differences in chip size and consequently in capacitive charge and ON-resistance is restricted. However, the results show the rapid progress in these devices when compared to commercial SiC rectifiers. [ABSTRACT FROM AUTHOR]

The dry etching of high crystal quality c-plane AlN grown by metal organic chemical vapor deposition was examined as a function of source and chuck power in inductively coupled plasmas of Cl2/Ar or Cl2/Ar/CHF3. Maximum etch rates of ∼1500 Å min−1 were obtained at high powers, with selectivity over SiO2 up to 3. The as-etched surfaces in Cl2/Ar/CHF3 have F-related residues, which can be removed in NH4OH solutions. The Al-polar basal plane was found to etch slowly in either KOH or H3PO4 liquid formulations with extensive formation of hexagonal etch pits related to dislocations. The activation energies for KOH- or H3PO4-based wet etching rates within these pits were 124 and 183 kJ/mol, respectively, which are indicative of reaction-limited etching. [ABSTRACT FROM AUTHOR]

This study aimed to comprehensively assess the influence of the nanotube diameter and the presence of a silicon carbide (SiC) coating on microbial proliferation on nanostructured titanium surfaces. An experiment used 72 anodized titanium sheets with varying nanotube diameters of 50 and 100 nm. These sheets were divided into four groups: non-coated 50 nm titanium nanotubes, SiC-coated 50 nm titanium nanotubes, non-coated 100 nm titanium nanotubes, and SiC-coated 100 nm titanium nanotubes, totaling 36 samples per group. P. gingivalis and T. denticola reference strains were used to evaluate microbial proliferation. Samples were assessed over 3 and 7 days using fluorescence microscopy with a live/dead viability kit and scanning electron microscopy (SEM). At the 3-day time point, fluorescence and SEM images revealed a lower density of microorganisms in the 50 nm samples than in the 100 nm samples. However, there was a consistently low density of T. denticola across all the groups. Fluorescence images indicated that most bacteria were viable at this time. By the 7th day, there was a decrease in the microorganism density, except for T. denticola in the non-coated samples. Additionally, more dead bacteria were detected at this later time point. These findings suggest that the titanium nanotube diameter and the presence of the SiC coating influenced bacterial proliferation. The results hinted at a potential antibacterial effect on the 50 nm diameter and the coated surfaces. These insights contribute valuable knowledge to dental implantology, paving the way for developing innovative strategies to enhance the antimicrobial properties of dental implant materials and mitigate peri-implant infections. [ABSTRACT FROM AUTHOR]

It has recently been demonstrated that electron beam injection into p-type β-gallium oxide leads to a significant linear increase in minority carrier diffusion length with injection duration, followed by its saturation. The effect was ascribed to trapping of non-equilibrium electrons (generated by a primary electron beam) at meta-stable native defect levels in the material, which in turn blocks recombination through these levels. In this work, in contrast to previous studies, the effect of electron injection in p-type Ga2O3 was investigated using cathodoluminescence technique in situ in scanning electron microscope, thus providing insight into minority carrier lifetime behavior under electron beam irradiation. The activation energy of ∼0.3 eV, obtained for the phenomenon of interest, is consistent with the involvement of Ga vacancy-related defects. [ABSTRACT FROM AUTHOR]

This study aims to explore the impact of outdoor education on senior elementary school students' perceptions of scientific literacy and learning motivation. 42 senior elementary school students (25 males, 17 females; average age = 11.6) were enrolled and divided into experimental (N = 21) and control (N = 21) groups. Participants were taught the same content about science for four weeks. The control group adopted traditional indoor teaching, whereas the experimental group adopted outdoor education. Before and after the course, each student completed the 23 items of scientific literacy and the 6 items of learning motivation scale. The results show that the experimental group had significantly higher perceptions of scientific literacy and learning motivation. The outdoor education teaching method has positive effects on the higher levels of awareness and creative development of students. These findings imply that outdoor education has a positive effect on improving students' perceptions of scientific literacy and learning motivation. [ABSTRACT FROM AUTHOR]