Giant Gating Tunability of Optical Refractive Index in Transition Metal Dichalcogenide Monolayers

We report that the refractive index of transition metal dichacolgenide (TMDC) monolayers, such as MoS2, WS2, and WSe2, can be substantially tuned by > 60% in the imaginary part and > 20% in the real part around exciton resonances using CMOS-compatible electrical gating. This giant tunablility is rooted in the dominance of excitonic effects in the refractive index of the monolayers and the strong susceptibility of the excitons to the influence of injected charge carriers. The tunability mainly results from the effects of injected charge carriers to broaden the spectral width of excitonic interband transitions and to facilitate the interconversion of neutral and charged excitons. The other effects of the injected charge carriers, such as renormalizing bandgap and changing exciton binding energy, only play negligible roles. We also demonstrate that the atomically thin monolayers, when combined with photonic structures, can enable the efficiencies of optical absorption (reflection) tuned from 40% (60%) to 80% (20%) due to the giant tunability of refractive index. This work may pave the way towards the development of field-effect photonics in which the optical functionality can be controlled with CMOS circuits

Non-monotonic compositional dependence of isothermal bulk modulus of the (Mg1–xMnx)Cr2O4 spinel solid solutions, and its origin and implication

AbstractThe compressibility of the spinel solid solutions, (Mg1−xMnx)Cr2O4 with x = 0.00 (0), 0.20 (0), 0.44 (2), 0.61 (2), 0.77 (2) and 1.00 (0), has been investigated by using a diamond-anvil cell coupled with synchrotron X-ray radiation up to ∼10 GPa (ambient T). The second-order Birch–Murnaghan equation of state was used to fit the PV data, yielding the following values for the isothermal bulk moduli (KT), 198.2 (36), 187.8 (87), 176.1 (32), 168.7 (52), 192.9 (61) and 199.2 (61) GPa, for the spinel solid solutions with x = 0.00 (0), 0.20 (0), 0.44 (2), 0.61 (2), 0.77 (2) and 1.00 (0), respectively (KT′ fixed as 4). The KT value of the MgCr2O4 spinel is in good agreement with existing experimental determinations and theoretical calculations. The correlation between the KT and x is not monotonic, with the KT values similar at both ends of the binary MgCr2O4MnCr2O4, but decreasing towards the middle. This non-monotonic correlation can be described by two equations, KT = −49.2 (11)x + 198.0 (4) (x ≤ ∼0.6) and KT = 92 (41)x + 115 (30) (x ≥ ∼0.6), and can be explained by the evolution of the average bond lengths of the tetrahedra and octahedra of the spinel solid solutions. Additionally, the relationship between the thermal expansion coefficient and composition is correspondingly reinterpreted, the continuous deformation of the oxygen array is demonstrated, and the evolution of the component polyhedra is discussed for this series of spinel solid solutions. Our results suggest that the correlation between the KT and composition of a solid solution series may be complicated, and great care should be paid while estimating the KT of some intermediate compositions from the KT of the end-members

A systematic bibliometric analysis on the clinical practice of CGM in diabetes mellitus from 2012 to 2022

BackgroundContinuous glucose monitoring (CGM) has revolutionized diabetes management, but a comprehensive analysis of its clinical implementation is lacking. This study aims to explore CGM in diabetes practice over the past decade using bibliometric analysis. It will identify trends, research focal points, and provide a framework for future investigations.Materials and methodsThe Web of Science Core Collection (WOSCC) was utilized to acquire literature pertaining to the employment of continuous glucose monitoring (CGM) in diabetes that was published between the years 2012 and 2022, and to conduct a comprehensive analysis of the associated citation data. To achieve bibliometric visualization and analysis of the collated data, the bibliography package in the Rstudio(v.4.2.2), Citespace 6.2.R4, and VOS viewer were employed.ResultsA total of 3024 eligible publications were extracted from 91 countries, with the United States being the leading country in terms of the number of issued articles. Furthermore, the annual publication rate has shown a gradual increase during the past decade. Among the various journals in this field, DIABETES TECHNOLOGY & THERAPEUTICS was identified as the most highly cited one. Keyword clustering analysis of the extracted publications indicates that the research hotspots in the past decade have primarily focused on “continuous glucose monitoring”, “glycemic variability”, “type 1 diabetes”, “hypoglycemia”, and “glycemic control”. Moreover, the analysis of keyword emergence reveals that “Time In Range” and “Young Adult” represent the current research frontiers for the years 2012-2022.ConclusionThe concept of Time in Range (TIR) has garnered considerable attention as a significant area of inquiry and an emerging research trend in the clinical practice of Continuous Glucose Monitoring (CGM) for Diabetes Mellitus. Moreover, recent investigations have demonstrated a growing focus on young adults with type 1 diabetes as the research population of interest. In the foreseeable future, research endeavors will persist in the pursuit of improving glycemic management among young adults through the utilization of continuous glucose monitoring (CGM) technology, while also delving into the examination of the Time in Range metric via supplementary clinical investigations

Constructing Synergistic Triazine and Acetylene Cores in Fully Conjugated Covalent Organic Frameworks for Cascade Photocatalytic H2O2 Production

Covalent organic frameworks (COFs) are an ideal template for photocatalytic H2O2 synthesis because of the tunable chemical structures and semiconductor properties. However, the photoactivity for COFs is still under-improved due to the inefficient intrinsic charge generation, fast recombination of photogenerated charges, and limited electron transport along the frameworks. Herein, spatially separated and synergistic triazine and acetylene units are first integrated into COFs (EBA-COF and BTEA-COF) for photocatalytic H2O2 production. The spatial separation of triazine and acetylene cores leads to efficient charge separation and suppressed charge recombination, and C═C linkage facilitates electrons transport over the skeletons. Both experimental and computational results suggested that triazine and acetylene units synergistically promote H2O2 synthesis in a two-electron pathway. The EBA-COF showed an attractive activity with a H2O2 production rate of 1830 μmol h-1 gcat-1, superior to that of most other COF-based catalysts. This study provides a method for designing photocatalysts with synergistic photocatalytic active sites based on vinylene-linked COFs

Practice Analysis of Road Traffic Crashes Accident of a City in China

Abstract. Many studies focused on the development of crash analysis approaches have resulted in aggregate practices and experiences to quantify the safety effects of human, geometric, traffic and environmental factors on the expected number of deaths, injuries, and/or property damage crashes at specific locations. Traffic crashes on roads are a major cause of road crashes in the metropolitan area of Xi'an. In an attempt to identify causes and consequences, reported traffic crashes for six years in Xi'an were analyzed using a sample of 2038 reports. The main types of information from such reports were extracted, coded, and statistically analyzed. Important results were obtained from frequency analyses as well as multiple contributory factors related to traffic crashes, including crash severity, time and location of occurrence, geometry of the road, AADT and v/c. This paper presents the results of such analyses and provides some recommendations to improve traffic safety and further studies to analyze potential crash locations

The recent research progress of polyphenol‐derived biomaterials in wound repair

Abstract The clinical requirements for wound care are increasing daily, and the global wound dressing market is expanding; however, the research and development of new wound dressings are imminent. Natural biomolecules such as polyphenols, have been widely used in this field of vision. Owing to their unique anti‐oxidative, adhesive, antibacterial and other bioactive functions, researchers have developed a series of wound dressings with excellent performance and applied them to a variety of biomaterials, such as hydrogels, nanofibers, films and scaffolds. They can effectively promote angiogenesis and fibroblast migration and proliferation, scavenge active oxygen free radicals, inhibit excessive inflammatory reactions at wound sites and ultimately accelerate wound healing. The authors summarise the latest progress in polyphenol‐derived biomaterials in skin wound repair to provide inspiration for future wound dressing research

Analysis of PM2.5 Variations Based on Observed, Satellite-Derived, and Population-Weighted Concentrations

Fine particulate matter (PM2.5), which can cause adverse human health effects, has been proven as the first air pollutant in China. In situ observations with ground-level monitoring and satellite-based concentrations have been used to analyze the variations in PM2.5. However, variation analyses based on these two kinds of measurement have mainly focused on the concentration itself and ignored the effects on the population. Therefore, this study not only investigated these two kinds of measurements, but also performed weighted population analyses to study the variations in PM2.5. Firstly, daily models of timely structure adaptive modeling (TSAM) were constructed to simulate satellite-derived PM2.5 levels from January 2013 to December 2016. Secondly, population-weighted concentrations were calculated based on TSAM-derived PM2.5 surfaces. Finally, observed, TSAM-derived, and population-weighted concentrations were used to analyze the variations in PM2.5. The results showed the different importance of various input parameters; AOD had the highest rank. Additionally, TSAM models demonstrated good performance, fitting R ranging from 0.86 to 0.91, and validating R from 0.82 to 0.89. According to the air quality standard in China, TSAM-derived PM2.5 showed that the increase in area lower than Level II was 29.03% and the increase in population was only 14.81%. This indicates that the air quality exhibited an overall improvement in spatial perspective, but some areas with high population density showed a relatively low improvement due to uneven distributions in China. The population-weighted PM2.5 concentration could better represent the health threats of air pollutants compared with in situ observations

Analysis of PM_2.5 Variations Based on Observed, Satellite-Derived, and Population-Weighted Concentrations

Fine particulate matter (PM2.5), which can cause adverse human health effects, has been proven as the first air pollutant in China. In situ observations with ground-level monitoring and satellite-based concentrations have been used to analyze the variations in PM2.5. However, variation analyses based on these two kinds of measurement have mainly focused on the concentration itself and ignored the effects on the population. Therefore, this study not only investigated these two kinds of measurements, but also performed weighted population analyses to study the variations in PM2.5. Firstly, daily models of timely structure adaptive modeling (TSAM) were constructed to simulate satellite-derived PM2.5 levels from January 2013 to December 2016. Secondly, population-weighted concentrations were calculated based on TSAM-derived PM2.5 surfaces. Finally, observed, TSAM-derived, and population-weighted concentrations were used to analyze the variations in PM2.5. The results showed the different importance of various input parameters; AOD had the highest rank. Additionally, TSAM models demonstrated good performance, fitting R ranging from 0.86 to 0.91, and validating R from 0.82 to 0.89. According to the air quality standard in China, TSAM-derived PM2.5 showed that the increase in area lower than Level II was 29.03% and the increase in population was only 14.81%. This indicates that the air quality exhibited an overall improvement in spatial perspective, but some areas with high population density showed a relatively low improvement due to uneven distributions in China. The population-weighted PM2.5 concentration could better represent the health threats of air pollutants compared with in situ observations