Superconductivity in the η\eta-carbide-type oxides Zr4Rh2Ox

We report on the synthesis and the superconductivity of Zr$_4$Rh$_2$O$_{x}$ ($x$ = 0.4, 0.5, 0.6, 0.7, 1.0). These compounds crystallize in the $\eta$-carbide structure, which is a filled version of the complex intermetallic Ti$_2$Ni structure. We find that in the system Zr$_4$Rh$_2$O$_{x}$, already a small amount ($x$ $\geq$ 0.4) of oxygen addition stabilizes the $\eta$-carbide structure over the more common intermetallic CuAl$_2$ structure-type, in which Zr$_2$Rh crystallizes. We show that Zr$_4$Rh$_2$O$_{0.7}$ and Zr$_4$Rh$_2$O are bulk superconductors with critical temperatures of $T_c \approx$ 2.8 K and 4.7 K in the resistivity, respectively. Our analysis of the superconducting properties reveal both compounds to be strongly type-II superconductors with critical fields up to $\mu_0 H_{c1}$(0) $\approx$ 8.8 mT and $\mu_0 H_{c2}$(0) $\approx$ 6.08 T. Our results support that the $\eta$-carbides are a versatile family of compounds for the investigation of the interplay of interstitial doping on physical properties, especially for superconductivity

Superconductivity in the η-carbide-type oxides Zr4Rh2Ox

We report on the synthesis and the superconductivity in (x = 0.4, 0.5, 0.6, 0.7, 1.0). These compounds crystallize in the η-carbide structure, which is a filled version of the complex intermetallic structure. We find that in the system , already a small amount (x 0.4) of oxygen addition stabilizes the η-carbide structure over the more common intermetallic structure-type, in which crystallizes. We show that and are bulk superconductors with critical temperatures of 2.8 K and 4.7 K in the resistivity, respectively. Our analysis of the superconducting properties reveal both compounds to be strongly type-II superconductors with critical fields up to (0) 8.8 mT and (0) 6.08 T. Our results support that the η-carbides are a versatile family of compounds for the investigation of the interplay of interstitial doping on physical properties, especially for superconductivity

Torque Enhancement of Dual Three-Phase PMSM by Harmonic Injection

The torque enhancement of dual three-phase permanent magnet synchronous machine (DT-PMSM) drive system by full exploitation of flux-linkage and current harmonics are comparatively studied in this paper. The torque capability of DT-PMSM is previously evaluated with strategies of harmonics utilization, i.e. Strategy-1 of 3rd harmonic utilization and Strategy-2 of 5th and 7th harmonic utilization, which can extend the torque capability by 18.2% and 9.0% respectively. However, the full exploitation of harmonics including 3rd, 5th and 7th harmonics in the dual three-phase system are not addressed. In this paper, the Strategy-3 of 3rd, 5th and 7th harmonic utilization is also included. Its corresponding harmonic current control is proposed and the average torque and harmonic torque are analyzed in detail. Based on a test rig with existing prototype DT-PMSM, the torque with Strategy-3 is increased up to 26.5%, which is superior to the previous strategies

Two-gap to single-gap superconducting transition on a honeycomb lattice in Ca1−xSrxAlSi

We report on the structural and microscopic superconducting properties of the Ca1−xSrxAlSi solid solution. Specifically, we have realized the continuous solid solution, which for all members, other than x=0 (CaAlSi), crystallizes in the AlB2-type structure. For CaAlSi, we present an improved structural model where all Al/Si layers are buckled, leading to a 6-folded structure along the crystallographic c direction. We, furthermore, find indications for the structural instability in the parent compound CaAlSi to enhance the superconductivity across the solid solution. Our investigation of the magnetic penetration depths by means of muon-spin rotation experiments reveals that CaAlSi is a two-gap superconductor, that SrAlSi is a single-gap superconductor, and that there is a continuous transition from one electronic state to the other across the solid solution. Hence, we show that the Ca1−xSrxAlSi solid solution is a highly tunable two-gap to single-gap superconducting system on a honeycomb lattice, where the superconductivity is strongly connected to a structural instability, i.e., the buckling of the Al/Si layers

The systematic review and meta-analysis evaluated the efficacy and safety of nefopam for catheter-related bladder discomfort based on randomized controlled trials

Background: Catheter-related bladder discomfort (CRBD) is a frequent occurrence following urinary catheterization during surgical procedures, as well as a commonly experienced bladder pain syndrome after surgery. There have been various studies on drugs and interventions to manage CRBD, but their comparative efficacy and safety are still a topic of debate. We conducted a meta-analysis to assess the efficacy and safety of nefopam for managing postoperative CRBD.Methods: A systematic search of PubMed, Embase, Cochrane Library, and Web of Science was conducted to find randomized controlled trials (RCTs) on using nefopam in postoperative CRBD. The study employed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Data analysis was performed using RevMan version 5.4.1.Results: Five RCTs with 405 patients were analyzed to evaluate the efficacy of nefopam on postoperative CRBD. Short-term and long-term periods were defined as within 6 h and longer than 12 h after surgery, respectively. The incidence and severity of CRBD were compared between the two groups during these time periods. The analysis proved that nefopam reduced the short-term incidence of postoperative CRBD (RR 0.36; 95% CI, 0.18–0.70; p = 0.003, I2 = 78%) and the long-term incidence (RR 0.49; 95% CI, 0.32–0.74; p = 0.0007, I2 = 0%) significantly. We compared the incidence of moderate-to-severe CRBD between groups based on the scaling system (none, mild, moderate, and severe). This was used to assess the severity of postoperative CRBD. The results showed that patients in the nefopam group had a significantly lower incidence of moderate-to-severe CRBD compared to those in the placebo group in the short-term (RR 0.19; 95% CI, 0.10–0.34; p < 0.00001; I2 = 0%). However, there were no significant differences between the two groups in the incidence of moderate-to-severe CRBD in the long-term (RR 0.61; 95% CI, 0.21–1.76; p = 0.36; I2 = 0%). There were no significant variations in the occurrence of adverse events between the nefopam and control groups, mainly including postoperative nausea and vomiting (PONV) (RR 1.14; 95% CI, 0.40–3.21; p = 0.81), and tachycardia (RR 0.25; 95% CI, 0.03–2.11, p = 0.20).Conclusion: The findings of this meta-analysis indicate that nefopam significantly reduced the incidence of short or long-term postoperative CRBD. Nefopam decreased the severity of postoperative CRBD, particularly significantly reducing the occurrence of moderate to severe CRBD in the short-term. Overall, patients have good tolerance and no apparent side effects.Systematic Review Registration: identifier PROSPERO (CRD42023475012

Uniaxial strain-induced phase transition in the 2D topological semimetal IrTe2

Strain is ubiquitous in solid-state materials, but despite its fundamental importance and technological relevance, leveraging externally applied strain to gain control over material properties is still in its infancy. In particular, strain control over the diverse phase transitions and topological states in two-dimensional transition metal dichalcogenides remains an open challenge. Here, we exploit uniaxial strain to stabilize the long-debated structural ground state of the 2D topological semimetal IrTe$_{2}$, which is hidden in unstrained samples. Combined angle-resolved photoemission spectroscopy and scanning tunneling microscopy data reveal the strain-stabilized phase has a 6 × 1 periodicity and undergoes a Lifshitz transition, granting unprecedented spectroscopic access to previously inaccessible type-II topological Dirac states that dominate the modified inter-layer hopping. Supported by density functional theory calculations, we show that strain induces an Ir to Te charge transfer resulting in strongly weakened inter-layer Te bonds and a reshaped energetic landscape favoring the 6×1 phase. Our results highlight the potential to exploit strain-engineered properties in layered materials, particularly in the context of tuning inter-layer behavior

(NH4)2AgX3 (X = Br, I): 1D Silver Halides with Broadband White Light Emission and Improved Stability

Recently, ternary copper(I) halides have emerged as alternatives to lead halide perovskites for light emission applications. Despite their high-efficiency photoluminescence (PL) properties, most copper(I) halides are blue emitters with unusually poor tunability of their PL properties. Here, we report the impact of substitution of copper with silver in the high-efficiency blue-emitting Cu(I) halides through hydrothermal synthesis and characterization of (NH4)2AgX3 (X = Br, I). (NH4)2AgX3 are found to exhibit contrasting light emission properties compared to the blue-emitting Cu(I) analogues. Thus, (NH4)2AgBr3 and (NH4)2AgI3 exhibit broadband whitish light emission at room temperature with PL maxima at 394 and 534 nm and full width at half-maximum values of 142 and 114 nm, respectively. Based on our combined experimental and computational results, the broadband emission in (NH4)2AgX3 is attributed to the presence of high-stability self-trapped excitons and defect-bound excitons. (NH4)2AgBr3 and (NH4)2AgI3 both have significantly improved air and moisture stability as compared to the related copper(I) halides, which are prone to degradation via oxidation. Our results suggest that silver halides should be considered alongside their copper analogues for high-efficiency light emission applications.This material is based upon work supported by the National Aeronautics and Space Administration under Agreement No.80NSSC19M0140 issued through NASA Oklahoma EPSCoR.M.-H.D. was supported by the U.S. Department of Energy,Office of Science, Basic Energy Sciences, Materials Sciences,and Engineering Division. Open Access fees paid for in whole or in part by the University of Oklahoma Libraries.Ye

Electronic structure of few-layer black phosphorus from μ\mu-ARPES

Black phosphorus (BP) stands out among two-dimensional (2D) semiconductors because of its high mobility and thickness dependent direct band gap. However, the quasiparticle band structure of ultrathin BP has remained inaccessible to experiment thus far. Here we use a recently developed laser-based micro-focus angle resolved photoemission ($\mu$-ARPES) system to establish the electronic structure of 2-9 layer BP from experiment. Our measurements unveil ladders of anisotropic, quantized subbands at energies that deviate from the scaling observed in conventional semiconductor quantum wells. We quantify the anisotropy of the effective masses and determine universal tight-binding parameters which provide an accurate description of the electronic structure for all thicknesses.Comment: Supporting Information available upon reques