Geometric effects of a quarter of corrugated torus

In the spirit of the thin-layer quantization scheme, we give the effective Shr\"{o}dinger equation for a particle confined to a corrugated torus, in which the geometric potential is substantially changed by corrugation. We find the attractive wells reconstructed by the corrugation not being at identical depths, which is strikingly different from that of a corrugated nanotube, especially in the inner side of the torus. By numerically calculating the transmission probability, we find that the resonant tunneling peaks and the transmission gaps are merged and broadened by the corrugation of the inner side of torus. These results show that the quarter corrugated torus can be used not only to connect two tubes with different radiuses in different directions, but also to filter the particles with particular incident~energies.Comment: 7 pages, 8 figure

3-Bromo-1-(3-chloro­pyridin-2-yl)-N-(4-eth­oxy­phen­yl)-1H-pyrazole-5-carbox­amide

In the title compound, C17H14BrClN4O2, the pyrazole ring is almost coplanar with the benzene ring [dihedral angle = 0.5 (2)°], whereas the pyrazole ring is close to perpendicular to the 3-chloro­pyridine ring [dihedral angle = 73.7 (2)°]. An intra­molecular C—H⋯O hydrogen bond occurs. The dominant inter­action in the crystal packing is an N—H⋯N hydrogen bond, which generates a chain along the c axis. Weak inter­molecular C—H⋯O and C—H⋯N contacts are also observe

Methyl 3-(cyclo­propyl­meth­oxy)-4-hy­droxy­benzoate. Corrigendum

Corrigendum to Acta Cryst. (2010), E66, o2004

Quantum mechanics of fermion confined to a curved surface in Foldy-Wouthuysen representation

In Foldy-Wouthuysen representation, we deduce the effective quantum mechanics for a particle confined to a curved surface by using the thin-layer quantization scheme. We find that the spin effect caused by confined potential as the results of relativistic correction in the non-relativistic limit. Furthermore, the spin connection appeared in curved surface which depends on curvature contributes a Zeeman-like gap in the relativistic correction term. In addition, the confined potential also induces a curvature-independent energy shift, which is from the zitterbewegung effect. As an example, we apply the effective Hamiltonian to torus surface, in which we obtain expectantly the spin effects related to confined potential. Those results directly demonstrate the scaling of the uncommutation of the non-relativistic limit and the thin-layer quantization formalis

Association of composite dietary antioxidant index with cardiovascular disease in adults: results from 2011 to 2020 NHANES

BackgroundOxidative stress is a known pathogenic mechanism in cardiovascular disease (CVD), yet the association between dietary antioxidants and CVD in the general population remains underexplored. This study leverages data from the National Health and Nutrition Examination Survey (NHANES) to investigate the association of a composite dietary antioxidant index with CVD in US adults.MethodsAnalyzing data from 25,997 adults (2011–2020 NHANES), we employed weighted generalized linear models, subgroup analysis, threshold effect analyses, and sensitivity analysis to assess the association between dietary antioxidants and CVD. Nonlinear associations were explored through a restricted cubic spline, with gender-specific stratification and threshold effect analysis to identify critical inflection points.ResultsIncreasing levels of the composite dietary antioxidant index corresponded with decreased CVD prevalence (P < 0.001). In all models, weighted generalized linear models revealed a consistent negative association between CVD prevalence. And in Model 3, Quartile 4 had a 29% lower CVD prevalence than Quartile 1[0.71 (0.59, 0.85), P < 0.001]. Meanwhile, the findings of the unweighted logistic regression model demonstrated stability. Various characteristics such as sex, age, race, PIR, education, BMI, alcohol consumption, hypertension, hyperlipidemia, and diabetes did not influence this inverse association (P for interaction >0.05). Notably a nonlinear association was observed, with a significant inflection point at 3.05 among women.ConclusionThis study demonstrates a strong negative association between the composite dietary antioxidant index and CVD prevalence, suggesting the potential protective role of dietary antioxidants. These findings underscore the need for prospective studies to further understand the impact of oxidative stress on cardiovascular health

Controlled growth of atomically thin transition metal dichalcogenides via chemical vapor deposition method

Two-dimensional (2D) transition metal dichalcogenides (TMDC) have attracted great research interest due to their potential application in electronics, optoelectronics, electrocatalysis, and so on. To satisfy expectations, high-quality materials with designed structures are highly desired through the controlled growth of TMDC. Chemical vapor deposition (CVD) offers facile control in synthesizing 2D TMDC as well as a high degree of freedom for tuning their structures and properties. In this review, we elaborate on recent advances in CVD techniques for synthesizing atomically thin TMDC. The novel techniques for achieving continuous uniform 2D films are provided along with insights into the growth mechanisms. Moreover, approaches toward high-quality materials by growing large single crystals and oriented domains are thoroughly summarized. The strategies for controlling the crystal thickness, phase, and doping condition are also discussed. Finally, we address the challenges in the field and prospective research directions

The Effects of Inhomogeneous Microstructure and Loading Waveform on Creep-Fatigue Behaviour in a Forged and Precipitation Hardened Nickel-based Superalloy

The aim of the present paper is to identify the effects of sampling locations and loading waveforms on high-temperature low-cycle fatigue (HTLCF) and creepfatigue life of a forged and precipitation hardened nickel-based GH4169 superalloy. Both the deformation and failure mechanisms are considered here. It has beenrevealed that HTLCF and creep-fatigue life of specimens were influenced by inhomogeneous microstructures at different locations. Compared with the HTLCF tests, the presence of dwell times in creep-fatigue tests tended to reduce number of cycles to failure. Intergranular damage was observed at both crack initiation andpropagation stages. For the dwell times under tension, the intergranular damage was mainly associated with precipitate-assist voids. However, oxidation accounted for the presence of intergranular damage for the dwell times under compression.<br/

Methyl 3,4-bis­(cyclo­propyl­meth­oxy)benzoate

The title compound, C16H20O4, was obtained unintentionally as the byproduct of an attempted synthesis of methyl 3-(cyclo­propyl­meth­oxy)-4-hy­droxy­benzoate. In the crystal, the mol­ecules are linked by inter­molecular C—H⋯O inter­actions

Methyl 3-(cyclo­propyl­meth­oxy)-4-hy­droxy­benzoate

In the title compound, C12H14O4, the dihedral angle between the benzene ring and the cyclo­propyl ring is 60.3 (4)°. In the crystal structure, mol­ecules are linked by inter­molecular O—H⋯O hydrogen bonds into chains running parallel to [101]