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The increasing demands of device applications in harsh environments have led to higher expectations for temperature and pressure resistance in high-temperature piezoelectric materials. In order to understand the performance characteristics of BiScO3-PbTiO3 (BS-PT) high-temperature piezoelectric materials in practical device applications, this study focuses on analyzing the dielectric, piezoelectric, and ferroelectric properties of BS-64PT ceramics under uniaxial stress up to 150 MPa, as well as its electromechanical performance under a hydrostatic pressure of up to 400 MPa. As the uniaxial pressure increases, both the bias-field and large-signal piezoelectric coefficients exhibit a pattern of initially increasing and subsequently decreasing. Furthermore, the bias-field piezoelectric coefficient exceeds 450 pC/N and the large-signal piezoelectric coefficient surpasses 630 pC/N under uniaxial pressures below 100 MPa. This highlights their exceptional resistance to depolarization caused by uniaxial stress. To obtain more precise piezoelectric properties for BS-64PT ceramics in the 31 and 33 modes under hydrostatic pressure, the admittance fitting method was utilized. This method takes into account the significant losses at higher pressures. Within the pressure range of 0–400 MPa, the values of d33 and d31 for BS-64PT ceramics exhibited a minor change of 7.6% and 8%, respectively. These findings indicate that BS-64PT ceramics exhibit more stable piezoelectric properties under both uniaxial and hydrostatic pressures when compared to the majority of Pb-based perovskite-structured materials. The exceptional stability of piezoelectric properties in BS-PT ceramics can be primarily attributed to their elevated anisotropy energy or coercivity field compared to other perovskite-structured Pb(Mg1/3Nb2/3)O3 (PMN) / Pb(Zr,Ti)O3 (PZT)-based ceramics reported. [ABSTRACT FROM AUTHOR]

Dense (Pb0.92Ba0.08)Nb2O6‐xmol% MnO2 with 0.25 wt% TiO2 ceramics with a single orthorhombic phase were synthesized through a conventional solid‐state reaction method. Excellent piezoelectric performance (d33 = 90 pC/N) and low dielectric loss (tan δ = 0.5%) are achieved in Mn‐doped samples. Interestingly, the dielectric anomalies are observed in the temperature range of 300–400°C, which could be completely suppressed through Mn doping. The dielectric anomalies are associated with thermally activated domain wall motion, which could be constrained by the defect dipoles produced by Mn doping. More importantly, all samples experience about 12% performance degradation below 300°C, attributed to an accelerated aging process at elevated temperatures. After thermal aging, the samples exhibit excellent performance stability within the temperature range of 25–450°C, showing no further degradation. The results indicate that the PbNb2O6‐based ceramics are promising high‐temperature piezoelectric materials for piezoelectric devices operating at temperatures up to 450°C. [ABSTRACT FROM AUTHOR]

The electromechanical properties of [001]‐textured Mn‐PMN‐PZT ceramics are characterized under a hydrostatic pressure of up to 400 MPa. The dielectric constant of textured ceramics increases first and then decreases as pressure increases. A comparison of the electromechanical constants sij, kij, and dij (i, j = 1, 3) obtained by the method of direct calculation and admittance fitting is displayed in this work. The results show that the two methods can obtain similar results at lower pressures. When the pressure is relatively high, the loss cannot be ignored, and the results of the two methods are quite different. The admittance fitting method gives a more accurate piezoelectric constant. Under 400 MPa, textured ceramics have k31 = 0.55, d31 = 321 pC/N, k33 = 0.89, and d33 = 702 pC/N, while random ceramics have k31 = 0.33, d31 = 92 pC/N, k33 = 0.71, and d33 = 230 pC/N. The large piezoelectric properties of textured ceramics under high pressure make them potential underwater transducers. [ABSTRACT FROM AUTHOR]

Ruminococcus gnavus (R. gnavus) is a gram positive anaerobe and a member of the normal intestinal flora of humans. Here, we present a case study of bloodstream infection caused by R. gnavus in an 85 year old man. We identified R. gnavus using target DNA sequencing. The patient was treated with intravenous meropenem and ceftriaxone based on antimicrobial susceptibility tests. He recovered well and was discharged. [ABSTRACT FROM AUTHOR]

Abstract: CoTMPP-TiO2NT/BP composites have been synthesized by preparing CoTMPP and depositing CoTMPP on carbon-supported titania nanotube (TiO2NT/BP) using microwave irradiation method at the same time, followed by heat-treatment from 300 to 900°C in N2 atmosphere. The catalytic activity for oxygen reduction was evaluated by rotating disc electrode technique in half cells with 0.5M H2SO4. The number of electrons exchanged during ORR and the percentage of peroxide (%H2O2) produced by the reaction were evaluated for catalysts by rotating ring disk electrode (RRDE) measurements. The influences of TiO2NT doping, the heat-treating temperature and the different ratios of BP:TiO2NT on the activity of electrocatalysts for oxygen reduction were investigated. The stability of the CoTMPP-TiO2NT/BP electrocatalysts was studied with potentialstatic-polarization measurements in 0.5M H2SO4 +0.5M CH3OH. CoTMPP-TiO2NT/BP composites show higher catalytic activity and better stability than CoTMPP/BP. The mechanism for the enhanced catalytic activity of CoTMPP-TiO2NT/BP is discussed. [Copyright &y& Elsevier]