X-Ray Diffraction Analysis Of Gallium Oxide Thin Films Synthesized By A Simple And Cost-Effective Method

Wide energy gap beta type gallium oxide (Ga2O3) semiconductor material has attracted many researchers’ interests due its thermal and chemical stability. For synthesising Ga2O3 thin films, sol-gel spin coating is a simple and cost-efficient method, especially for spin coating on cheap substrate such as silicon (Si) substrate. However, little is known about the spin coating growth of the Ga2O3 thin films on Si substrate. In this paper, special attention was paid to the pre-treatment of the Si substrate and the coated layer prior and post spin coating because the uniformity and the quality of the synthesized films are strongly affected by the surface conditions of the substrate/layer. To access the structural and crystallite quality of the deposited Ga2O3, X-ray diffraction measurements were carried out and in-depth analyses using Williamson-Hall and size-strain plots methods were performed. The results show that the crystallite size of the spin coated Ga2O3 on Si is not influenced by the micro strain

Effects Of Dry Oxidation Treaments On The Characteristics Of Gallium Oxide Thin Films Prepared Using Sol-Gel Spin Coating Method

In this paper, gallium oxide (Ga2O3) thin films were grown on silicon (Si) substrate using a relatively simple and low-cost sol-gel spin coating method followed dry oxidation process. Two series of dry oxidation experiments were conducted, i.e., (i) annealing at different oxygen flow rates (i.e., from 2 L/min – 5 L/min) under 1100°C, and (ii) annealing at oxygen flow rate of 5 L/min under different temperatures (i.e., from 800°C to 1100°C). The effects of the oxygen gas flow rates under different temperatures on the structural, surface morphology, and optical properties of the deposited films were investigated. All results revealed that crystalline Ga2O3 layers were formed. From the X-ray diffraction results, all deposited films exhibit two prominent diffraction peaks corresponding to the Ga2O3 (1 ̅10) and (002). The annealing at different temperatures experiments showed that the surface roughness and the grains size increased as the temperature increases from 800°C to 1100°C. The optical band gap energy of the deposited films was extracted from the Ultraviolet-violet transmission spectra. This obtained energy bandgap is within the ranges of 4.69 – 4.83 eV, i.e., in reasonable agreement with the reported values. In summary, all the results showed that polycrystalline Ga2O3thin films were able to be grown on p-Si (100) substrate through the proposed methodology. While the best conditions for the dry oxidation process are at the oxygen flowrate of 5 L/min at temperature of 1100o C

Development of Nutrition Literacy Scale for Middle School Students in Chongqing, China: A Cross-Sectional Study

Background: Information on nutrition literacy of middle schoolers is limited and tools for measuring nutrition literacy of middle schoolers are inadequate. Nutrition literacy has a positive effect on health. Improving children's nutrition literacy can help them to master the necessary nutritional knowledge, develop a healthy lifestyle, and learn to supplement nutrition according to their own needs for healthy growth. Objectives: To develop the Chongqing Middle school student Nutrition Literacy Scale (CM-NLS). Methods: Three experiments were conducted. A theoretical framework and an initial item pool of CM-NLS were established based on the literature review. And the two-round Delphi method was used to explore the suitable acceptance indicators and items. Item evaluation and reduction were performed using the classical test theory. Then, the items in the final CM-NLS were tested for their validity and reliability amongst 462 middle school students. The construct validity was assessed using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). The internal consistency reliability and split-half reliability were evaluated using Cronbach's alpha coefficients. Results: The final CM-NLS consisting of 52 items that were based on three primary items (functional, interactive and critical) and six sub-items (obtain, understand, apply, interact, medial literacy and critical skill) was developed and validated. EFA suggested six factors explaining 69.44% of the total variance (Kaiser–Meyer–Olkin test = 0.916, Bartlett's test χ2 = 5,854.037, P < 0.001). CFA showed that the model fit the data adequately, with χ2/df = 1.911, root mean square error of approximation = 0.063, goodness-of-fit index = 0.822 and adjusted goodness of fit index = 0.790. The total CM-NLS Cronbach's alpha values of internal consistency and split-half reliability were 0.849 and 0.521, respectively, with reasonable reliability. Conclusions: CM-NLS is a valid and reliable instrument for assessing nutrition literacy among middle school students in Chongqing. Specifically, it could be used by practitioners for needs assessment before the implementation of a nutrition education program.This work was supported by the Chinese Nutrition Society (Science Popularization and Communication Research Fund project, Award Number CNS-SCP2020-34)

Association between modes of delivery and postpartum dietary patterns: A cross-sectional study in Northwest China

Objective: Puerperae’ dietary patterns (DPs) during the puerperium may be influenced by the mode of delivery, but population studies on this topic are scarce. This study aims to explore the relationship between DPs and different modes of delivery among puerperae. Methods: A cross-sectional study was conducted on 3,345 parturients in Lanzhou, China. The postpartum food intake was measured by a food frequency questionnaire (FFQ). Factor analysis was used to determine the DPs. Multiple linear regression was employed to examine the association between the mode of delivery and DP. Results: In this study, two DPs, i.e., traditional and modern DPs, were identified. Traditional DP was characterized by high energy-adjusted intake of tubers, coarse cereals, rice, whole grains, fishery products, and eggs. Modern DP included a high intake of coffee, non-sugary drinks, wine, tea, and fishery products. Compared with participants with vaginal delivery (reference category), cesarean section had an inverse association with modern DP (β: −0.11, 95% CI: −0.36, −0.09). A significant interaction was found between education level, monthly household income, alcohol drinking, and modes of delivery. The inverse association between cesarean section and modern DP or the intake of coffee was significant among puerperae with higher or lower monthly household income. However, the inverse association between cesarean section and traditional DP was only found among puerperae with higher monthly household income. Moreover, among the participants with high education, cesarean section was positively associated with intake of vegetables. Conclusion: Cesarean puerperae with higher levels of education and those with lower and higher monthly household income had less unhealthy foods intake than those who had vaginal delivery. They need to be accounted for in educational programs and interventions focused on healthy diet recommendations in puerperium.This project was funded by the Chongqing Social Science Planning Project (2017YBSH057) and joint project of the Ministry of Technology and Ministry of Health (2021MSXM215) and Discipline Cultivation Fund of the First Affiliated Hospital of Chongqing Medical University. The funders had no role in the design, analysis, data interpretation and publication of findings

Spin Coated Gallium Oxide Thin Films And The Effect Of Mo-Doping Concentration On Luminescence Properties

Beta-type gallium oxide (β-Ga2O3) with ultra-wide band gap energy and good emission property is suitable for optoelectronic applications such as luminescence devices. However, the growth of good quality β-Ga2O3 films using low cost and simple techniques, particularly the sol-gel spin coating technique, is still remains challenging. For luminescence features, undoped and doped β-Ga2O3 emit multicolour emissions due to the multi-energy level of intrinsic vacancies, which is unsuitable for the display application. From the fundamental and engineering point of view, it is worth investigating the above topics. In this project, the β-Ga2O3 thin films synthesized by the sol-gel spin coating method and their photoluminescence were investigated. For the fabrication, the sol-gel spin coating growth conditions, and processes of the β-Ga2O3 thin films on Si and Al2O3 substrates were investigated. Special treatments on the substrate and the coated layer were conducted to improve the uniformity and smoothness of each coated layer and the final deposited film. Different spin coating cycles, and annealing temperatures were also investigated from the morphologic and optical aspects. Finally, a set of samples with 6-layers spin-coated films and annealed under different temperatures, i.e., from 900 °C, to 1100 °C were prepared. These samples were then subjected to an in-depth X-ray diffraction analysis. The results show that the micro strain is not the key factor for the Bragg peaks broadening. To investigate luminescence properties, a series of Mo-doped β-Ga2O3 on Al2O3 were synthesized. A green luminescence band associated with the Mo ion dxz-dyz band transition appeared slowly with the increase of the Mo-doping concentration

Effects Of Dry Oxidation Treaments On The Characteristics Of Gallium Oxide Thin Films Prepared Using Sol-Gel Spin Coating Method

In this paper, gallium oxide (Ga2O3) thin films were grown on silicon (Si) substrate using a relatively simple and low-cost sol-gel spin coating method followed dry oxidation process. Two series of dry oxidation experiments were conducted, i.e., (i) annealing at different oxygen flow rates (i.e., from 2 L/min – 5 L/min) under 1100°C, and (ii) annealing at oxygen flow rate of 5 L/min under different temperatures (i.e., from 800°C to 1100°C). The effects of the oxygen gas flow rates under different temperatures on the structural, surface morphology, and optical properties of the deposited films were investigated. All results revealed that crystalline Ga2O3 layers were formed. From the X-ray diffraction results, all deposited films exhibit two prominent diffraction peaks corresponding to the Ga2O3 (1 ̅10) and (002). The annealing at different temperatures experiments showed that the surface roughness and the grains size increased as the temperature increases from 800°C to 1100°C. The optical band gap energy of the deposited films was extracted from the Ultraviolet-violet transmission spectra. This obtained energy bandgap is within the ranges of 4.69 – 4.83 eV, i.e., in reasonable agreement with the reported values. In summary, all the results showed that polycrystalline Ga2O3thin films were able to be grown on p-Si (100) substrate through the proposed methodology. While the best conditions for the dry oxidation process are at the oxygen flowrate of 5 L/min at temperature of 1100oC

Tunable circular dichroism of composite metamaterial on the basis of the phase transition of VO

The circular dichroism (CD) effect characterized by different optical responses between left and right circularly polarized lights is widely applied for polarization-resolved detection and imaging. The tunable CD effect is of substantial importance in improving the detection sensitivity and imaging resolution. In this paper, we show that planar Z-shaped composite metamaterial embedded with VO2 that exhibits insulator-metal transition (IMT) can enable thermally tunable chirality. Simulated by the finite element method, the tunable CD effect can be achieved by changing the environment temperature to initiate the IMT of VO2. We also demonstrate that the underlying mechanism of the CD effect generation is the electric multipole oscillation response in the vicinity of the VO2 gap in vertical direction. These findings not only provide a new strategy to change chirality and tune the effect of CD dynamically but also broaden its potential applications in polarization-resolved detection and imaging

Differences in Awareness of Chinese Dietary Guidelines Among Urban and Rural Residents: A Cross-Sectional Survey in Southwest China

Objectives: This study aimed to compare the awareness of Chinese dietary guidelines (CDGs, 2016) between rural and urban areas in Southwest China and identify the factors that affect CDGs (2016) awareness. Methods: This cross-sectional survey included 8,320 individuals aged 18-75 years from Chongqing, Sichuan, Guizhou, and Yunnan, China. Convenience sampling method was adopted to select the survey subjects and face-to-face surveys in each region were conducted to collect data. Descriptive statistics and generalized linear model were used to evaluate differences in awareness of CDGs among urban and rural residents and its influencing factors. Results: Overall CDGs awareness was low in urban and rural areas, although the awareness rate was higher in the former than in the latter (29.1% vs. 19.9%, respectively). Region, education level, Body Mass Index (BMI), gender, income, and age are the influencing factors of CDGs awareness. Urban participants were likely to acquire relevant knowledge from social media, books/magazines, family/friends, and experts. However, rural participants were likely to acquire relevant knowledge from food sales staff (p < 0.05). Conclusion: Rural residents are less aware of CDGs than their urban counterparts in Southwest China. Future dietary education should adopt different strategies for different populations, with considerable focus on rural residents.This project was funded by the science popularization and communication research fund of China Nutrition Society (Award Number CNS-SCP2020-34).Scopu

Influence of adolescents' and parental dietary knowledge on adolescents' body mass index (BMI), overweight/obesity in 2004-2015: a longitudinal study

Objective: The global epidemic of overweight/obesity in children and adolescents poses a significant public health threat. This longitudinal study aims to investigate the relationship between adolescents' and their parents' dietary knowledge and overweight/obesity among adolescents in China. Methods: Data were collected from the China Health and Nutrition Survey (CHNS) in 2004, 2006, 2009, 2011 and 2015. Overweight/obesity was defined according to the International Obesity Task Force (IOTF) cut-off for body mass index (BMI). A set of questions were used to assess the dietary knowledge scores of both adolescents and their parents during face-to-face interviews. Mixed effect models were used to analyze the data. Results: A total of 2035 adolescents aged 12-17 years were included in the data analysis. The mean BMI increased from 19.2 in 2004 to 20.5 in 2015, with a significant increase in the prevalence of overweight and obesity from 6.8% and 0.5% in 2004 to 15.1% and 7.8% in 2015, respectively. Adolescents with medium-score dietary knowledge were less likely to be overweight/obese compared to those with low-score dietary knowledge (OR (95% CI): 0.20 (0.05-0.80), P 0.05). Additionally, a significant interaction between adolescents' dietary knowledge score and education in relation to adolescents' BMI (P for interaction < 0.05). Conclusion: Adolescents with medium dietary knowledge were less likely to be overweight/obese than those with low knowledge, but no association was found with parental knowledge. Promoting nutritional education and healthy eating habits is vital to prevent overweight/obesity.This research uses data from China Health and Nutrition Survey (CHNS).We thank the National Institute for Nutrition and Health, China Center for Disease Control and Prevention, Carolina Population Center (P2C HD050924, T32 HD007168), the University of North Carolina at Chapel Hill, the NIH (R01-HD30880, DK056350, R24 HD050924, and R01-HD38700) and the NIH Fogarty International Center (D43 TW009077, D43 TW007709) for financial supportfor the CHNS data collection and analysis files from 1989 to 2015 and future surveys, and the China-Japan Friendship Hospital, Ministry of Health for support for CHNS 2009, Chinese National Human Genome Center at Shanghai since 2009, and Beijing Municipal Center for Disease Prevention and Control since 2011. We also express our gratitude to China Nutrition Society for the science popularization and communication research fund (grant number CNS-SCP2020-34).Scopu

Novel bimetallic oxido-bridged phenolato hafniumIV complex with enhanced anti-tumor activity and aqueous stability

A novel dimeric phenolato Hafnium complex [{HfIV(Salan2,4-Me)(OnBu)}2O] was synthesized by reacting [HfIV(Salan2,4-Me)2] in the presence of 100 equiv. of H2O. The structure was characterized by 1H, 13C NMR spectroscopy, HRMS and X-Ray diffraction. In comparison with [HfIV(Salan2,4-Me)2] and another precursor [{HfIV(Salan2,4-Me)(OnBu)}2O], this dimeric HfIV complex demonstrated enhanced aqueous stability and anti-tumor activity (IC50: 71.2 ± 25.3 μM against Hela S3 cells; 62.2 ± 27.7 μM against Hep G2 cells). Furthermore, this dimeric HfIV complex can only be synthesized from [HfIV(Salan2,4-Me)2] in low equivalent of H2O, upon addition of 2,6-dipicolinic acid, it can be transformed to a Salan/Dipic HfIV bis-chelated complex