Effect of oxidizing treatment on electrocatalytic activity of boron‑doped amorphous carbon thin films

Chen‑Song Wang,Ni Suo,Hao Huang,Ai‑min Wu,Guo‑Zhong Cao,Gui‑Feng Zhang 한국탄소학회 2019 Carbon Letters Vol.29 No.5

Boron-doped amorphous carbon (BDAC) thin films with a regular oxygen reduction reaction (ORR) catalytic activity were synthesized in a hot filament chemical vapor deposition device using a mixture of CH4 and H2 as a gas source and B2O3 as a boron source and then oxidized in air at 380–470 °C for 15–75 min. Scanning electron microscope, transmission electron microscope, Raman spectroscopy, X-ray photoelectron spectroscopy, and electrochemical tests were used to characterize the physical and electrochemical properties of the BDAC catalysts. It was concluded that the BDAC catalyst oxidized at 450 °C for 45 min showed the best ORR catalytic activity in alkaline medium. The oxygen reduction potential and the transfer electron number n, respectively, are − 0.286 V versus Ag/AgCl and 3.24 from the rotating disk electrode experiments. The treated carbon film has better methanol resistance and stability than the commercial Pt/C catalyst.

Irradiation Application on the Preparation of Emergency Food

Chen Hao 한국식품영양과학회 2011 한국식품영양과학회 학술대회발표집 Vol.2011 No.10

Models and Simulation of the Switched Reluctance Motor Drive System

Hao Chen,Jin-Woo Ahn 대한전기학회 2002 KIEE International Transactions on Electrical Mach Vol.2-B No.4

Optimal Threshold of LTE-Femtocell Network Based Bayes-Nash Equilibrium Theory

Hao Chen,Kan Liu,Wu Tunhua 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.6

To increase LTE (long time evolution) networks spectrum utilization and interference mitigation, a LTE system overlaid with femtocells is studied. This paper will focus a self-optimized power control scheme for LTE-femtocell networks, in which the transmitted power of a femtocell base station is adjusted based on the optimal SINR threshold. It is known that game theory is a useful tool for analyzing outage probabilities and optimal power in wpszireless networks. In this paper, Bayes-Nash equilibrium theory is used to derive a optimal SINR (signal-interference-noise-ratio) threshold from each femtocell. The power control scheme can be applied to realistic LTE-femtocell networks to enable robust communication against cross-tier interference thereby obtaining a substantial link quality.

Current state of research about acupuncture for the treatment of COVID-19: A scoping review

Chen Chen,Jie Zhan,Hao Wen,Xiaojing Wei,Lu Ding,Chenyang Tao,Cui Li,Peiming Zhang,Yuyuan Tang,Jing-chun Zeng,Li-ming Lu 한국한의학연구원 2021 Integrative Medicine Research Vol.10 No.-

Background Since the outbreak of coronavirus disease (COVID-19), acupuncture has been widely used in the treatment of COVID-19. The research community has responded rapidly and has already published many research articles about this topic. Methods We searched PubMed, Embase, Cochrane Library as well as CNKI, Wanfang and VIP from January 1, 2020 to July 31, 2021. The dates of publication, language of publication, methodological characteristics and the key findings were analyzed separately. The data are presented as bar graphs, structured tables and figures. Results In this scoping review, 16 research articles were included: 7 case reports, 6 observational studies, 1 review, 1 RCT and 1 nonrandomized clinical trial. The majority of the articles (81.3%) were published by Chinese scholars, 12.5% articles were by scholars in the United States, and 6.3% articles were by scholars in Iran. The included studies reported that acupuncture could alleviate the symptoms of COVID-19 patients, shorten their hospitalization days, and is effective for the elderly. There were no side effects reported. The most frequent acupoints used were LI4, PC6, ST36 and KI3. They reported many obstacles in implementing acupuncture therapy for treating COVID-19 patients. Conclusion Acupuncture has a good effect for the treatment of COVID-19, but high-quality evidence support is still lacking. Coupled with the difficulties that acupuncturists experienced during the process of treatment, the promotion of acupuncture treatment for COVID-19 faces many obstacles. Background Since the outbreak of coronavirus disease (COVID-19), acupuncture has been widely used in the treatment of COVID-19. The research community has responded rapidly and has already published many research articles about this topic. Methods We searched PubMed, Embase, Cochrane Library as well as CNKI, Wanfang and VIP from January 1, 2020 to July 31, 2021. The dates of publication, language of publication, methodological characteristics and the key findings were analyzed separately. The data are presented as bar graphs, structured tables and figures. Results In this scoping review, 16 research articles were included: 7 case reports, 6 observational studies, 1 review, 1 RCT and 1 nonrandomized clinical trial. The majority of the articles (81.3%) were published by Chinese scholars, 12.5% articles were by scholars in the United States, and 6.3% articles were by scholars in Iran. The included studies reported that acupuncture could alleviate the symptoms of COVID-19 patients, shorten their hospitalization days, and is effective for the elderly. There were no side effects reported. The most frequent acupoints used were LI4, PC6, ST36 and KI3. They reported many obstacles in implementing acupuncture therapy for treating COVID-19 patients. Conclusion Acupuncture has a good effect for the treatment of COVID-19, but high-quality evidence support is still lacking. Coupled with the difficulties that acupuncturists experienced during the process of treatment, the promotion of acupuncture treatment for COVID-19 faces many obstacles.

Influence of Hydrogen on Al-doped ZnO Thin Films in the Process of Deposition and Annealing

Chen, Hao,Jin, Hu-Jie,Park, Choon-Bae,Hoang, Geun-C. The Korean Institute of Electrical and Electronic 2009 Transactions on Electrical and Electronic Material Vol.10 No.3

The Al-doped ZnO (AZO) films were deposited on a glass substrate by RF magnetron sputtering in pure Ar and $Ar+H_2$ gas ambient at temperature of $100^{\circ}C$ and annealed in hydrogen ambient at the temperature range from 100 to 300 $^{\circ}C$, respectively. It was found that either the addition of hydrogen to the sputtering gas or the annealing treatment effectively reduced the resistivity of the AZO films. When the AZO films were annealed at the temperature of 300 $^{\circ}C$ for lhr in a hydrogen atmosphere, the resistivity decreased from $2.60{\times}10^{-3}\;{\Omega}cm$ to $8.42{\times}l0^{-4}\;{\Omega}cm$ for the film deposited in pure Ar gas ambient. Under the same annealing conditions of temperature and hydrogen ambient, the resistivity of AZO films deposited in the $Ar+H_2$ gas mixture decreased from $8.22{\times}l0^{-4}\;{\Omega}cm$ to $4.25{\times}l0^{-4}\;{\Omega}cm$. The lowest resistivity of $4.25{\times}l0^{-4}\;{\Omega}cm$ was obtained by adding hydrogen gas to the deposition and annealing process. X-ray diffraction (XRD) pattern of all films showed preferable growth orientation of (002) plane. The average transmittance is above 85 % and in the range of 400-1000 nm for all films.

A Fast Voxel-based Method for Outlier Removal in Laser Measurement

Hao Chen,Yu Chen,Xu Zhang,Baiyuan Li,Xiaoqiang Liu,Xuefei Shi,Jie Shen 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.6

Discrete data points are noncontinuous without structural information. In this paper, we propose a new fast outlier removal method via voxel-based surface propagation. The main technical components of our approach include (a) an efficient and simple spatial partitioning scheme and (b) a specially-designed surface propagation method. Numerical analyses indicate that our method is about 10 times faster than an existing method and significantly better than other two methods in terms of denoising accuracy. This provides an efficient solution to handling noisy laser-scanning data.

Enhancement of Electrical Properties on ZnO: Al Thin Film due to Hydrogen Annealing and SiO₂ Coating in Damp-heat Environment

Chen, Hao,Jeong, Yun-Hwan,Park, Choon-Bae The Korean Institute of Electrical and Electronic 2009 Transactions on Electrical and Electronic Material Vol.10 No.2

The electrical stability of ZnO: Al thin films deposited on glass substrate by the RF magnetron sputtering method have been modified by a hydrogen annealing treatment and $SiO_2$ protection layer. AZO thin films were deposited at room temperature and different RF powers of 50, 100, 150, and 200 W to optimize the AZO film growth condition. The lowest value of resistivity of $9.44{\times}10^{-4}{\Omega}cm$ was obtained at 2 mtorr, room temperature, and a power level of 150 W. Then, the AZO thin films were annealed at $250-400^{\circ}C$ for 1 h in hydrogen ambient. The minimum resistivity obtained was $8.32{\times}10^{-4}{\Omega}cm$ as-annealed at $300^{\circ}C$. The electrical properties were enhanced by the hydrogen annealing treatment. After a 72 h damp-heat treatment in harsh conditions of a water steam at $110^{\circ}C$ for four representative samples, a degradation of electrical properties was observed. The sample of hydrogen-annealed AZO thin films with $SiO_2$ protection layer showed a slight degradation ratio(17%) of electrical properties and a preferable transmittance of 90%. The electrical stability of AZO thin films had been modified by hydrogen annealing treatment and $SiO_2$ protection layer.

The Relationship Between Night Shift Work and the Risk of Abnormal Thyroid-Stimulating Hormone: A Hospital-Based Nine-Year Follow-up Retrospective Cohort Study in Taiwan

Chen, Hsin-Hao,Chiu, Hsiao-Hui,Yeh, Tzu-Lin,Lin, Chi-Min,Huang, Hsin-Yi,Wu, Shang-Liang Occupational Safety and Health Research Institute 2021 Safety and health at work Vol.12 No.3

Background: Health-care providers typically undergo shift work and are subjected to increased stress. Night shift work may induce disturbed sleep cycles and circadian rhythm. The objective of this study was to explore if night shift workers (NSWs) show an increased risk of abnormal thyroid-stimulating hormone (TSH). Methods: We conducted a retrospective cohort study of 574 employees without thyroid disease and abnormal TSH at baseline who underwent annual check-ups between 2007 and 2016 in a medical center. NSWs were defined as those with working time schedules other than daytime hours. We calculated the incidence rate and estimated the adjusted hazard ratio (HR) for incident abnormal TSH and subclinical hypothyroidism compared with non-NSWs using a Cox regression model. Results: A total of 56 incident abnormal TSH cases and 39 subclinical hypothyroidism cases in NSWs were identified during 3000 person-years of follow-up. In models adjusted for age, sex, obesity, and working departments, we found no increased relative risk for incident abnormal TSH (HR: 0.72, 95% confidence interval: 0.33-1.60) or subclinical hypothyroidism (HR: 0.52, 95% confidence interval: 0.19-1.45) when comparing NSWs to non-NSWs; nor were incidence rates significantly different among exclusively medical employees after excluding administrative staff. Conclusion: In this hospital-based nine-year follow-up retrospective cohort study, NSWs were not associated with increased relative risk of incident abnormal TSH and subclinical hypothyroidism, in contrast to previous cross-sectional studies.

Characteristics and heterostructure of metal-doped TiO2/ZnO nanocatalysts

Chen Wu-Jhang,Hsu Kuo-Chin,Fang Te-Hua,Chen Tao-Hsing,Li Ming-Hao 한국물리학회 2022 Current Applied Physics Vol.38 No.-

In this study, Ag or Al-doped TiO2/ZnO heterostructure nanocatalysts were prepared using a sol-gel method for photocatalysis to evaluate the degradability. The photocatalytic behavior was evaluated by the degradation of methylene blue (MB) under ultraviolet (UV) light irradiation. Photocatalytic studies suggested that 1 mol% Agdoped TiO2/ZnO (TiO2/ZnO = 0.75/0.25) heterostructure nanocatalysts showed higher photocatalytic activity, and that the degradation efficiency can reach 83% in 4 h, 14% higher than that for pure TiO2. Finally, the photocatalysis mechanism for the Ag-doped TiO2/ZnO heterostructure nanocatalysts is discussed.