Template-free synthesis of hierarchical NiO microtubes as high performance anode materials for Li-ion batteries

Yiwen Hong,Jingxia Yang,Jingli Xu,최원묵 한국물리학회 2019 Current Applied Physics Vol.19 No.6

Hierarchical nanostructured NiO (h-NiO) microtubes were prepared by a simple wet-chemical synthesis without the use of template or surfactant, followed by the calcination of α-Ni(OH)2 precursor. The structural characterization of the h-NiO microtubes were performed by scanning microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD), the results of which indicated that the obtained h-NiO microtubes are covered by the nanosheet grown perpendicularly on the tube surface. The unique hierarchical nanostructure of h-NiO microtubes with high surface area and many voids facilitates the electrochemical reaction as well as the short ion and electron transport pathway. Therefore, as anode electrode of Li-ion batteries, the h- NiO microtubes deliver largely enhanced cycle capacity of 770 mAh·g−1 at a current density of 0.5 C after 200 cycles with high columbic efficiency, compared to the NiO rods. These results suggest that the h-NiO microtubes can be a promising anode material for Li-ion batteries.

A Novel Scheme for Sliding-Mode Control of DC-DC Converters with a Constant Frequency Based on the Averaging Model

Yiwen He,Weisheng Xu,Yan Cheng 전력전자학회 2010 JOURNAL OF POWER ELECTRONICS Vol.10 No.1

A new scheme for sliding-mode control (SMC) of DC-DC converters with a constant switching frequency is proposed. The scheme is based on the averaging model and the output signal of the controller is d? or d? instead of the on or off signal of a direct sliding-mode (SM) controller or the continuous signal d = ueq of an indirect SM controller. Two approaches using the new scheme are also proposed and the design procedures for a buck converter are given in detail. The first approach called constant d? and d? SMC is simple, cost effective and dynamically fast. In order to improve the dynamic characteristics of the reaching phase and to alleviate chattering, the second approach called reaching law SMC is also presented. Analyses and simulation results demonstrate the feasibility of the proposed scheme.

A Novel Scheme for Sliding-Mode Control of DC-DC Converters with a Constant Frequency Based on the Averaging Model

He, Yiwen,Xu, Weisheng,Cheng, Yan The Korean Institute of Power Electronics 2010 JOURNAL OF POWER ELECTRONICS Vol.10 No.1

A new scheme for sliding-mode control (SMC) of DC-DC converters with a constant switching frequency is proposed. The scheme is based on the averaging model and the output signal of the controller is $d^+$ or $d^-$ instead of the on or off signal of a direct sliding-mode (SM) controller or the continuous signal d = $u_{eq}$ of an indirect SM controller. Two approaches using the new scheme are also proposed and the design procedures for a buck converter are given in detail. The first approach called constant $d^+$ and $d^-$ SMC is simple, cost effective and dynamically fast. In order to improve the dynamic characteristics of the reaching phase and to alleviate chattering, the second approach called reaching law SMC is also presented. Analyses and simulation results demonstrate the feasibility of the proposed scheme.

Severe Cutaneous Adverse Reactions: A Single-Center Retrospective Study of 173 Patients in China

( Zhongyi Xu ),( Jie Shen ),( Yiwen Yang ),( Ruoyue Yuan ),( Leihong Flora Xiang ),( Chengfeng Zhang ) 대한피부과학회 2019 Annals of Dermatology Vol.31 No.5

Background: Severe cutaneous adverse reactions (SCAR) to drugs are a crucial public health issue and the use of systemic corticosteroids in SCAR has been controversial. Objective: To analyze clinical features, causative drugs, treatment, outcomes, and prognostic factors of SCAR in the case-series of 173 patients, and add more information to the debate of using systemic corticosteroids in SCAR management. Methods: A retrospective study of 173 SCAR patients diagnosed with drug reaction with eosinophilia and systemic symptoms (DRESS), Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) or acute generalized exanthematous pustulosis (AGEP) at a tertiary care institution in China between January 2014 and December 2017 was conducted. Results: Of 173 patients, allopurinol, carbamazepine, and antibiotics are the most frequently implicated drugs for DRESS (40.4%), SJS/TEN (26.0%), and AGEP (40.0%) respectively. Moreover, there is a strongly negative correlation between early corticosteroids use and the progression (p=0.000) and severity (p=0.01) of skin lesions. However, there is no association between early corticosteroids use and the mortality of SCAR (odds ratio: 1.01, 95% confidence interval: 0.95∼1.08). In addition, lymphadenopathy, eosinophilia, and interval from onset to corticosteroids treatment were correlated with SCAR prognosis. Conclusion: Prompt short-course systemic corticosteroids use is associated with early-stage skin lesions remission without influencing the disease mortality. Lymphadenopathy and eosinophilia were the independent poor prognostic factors of SCAR. (Ann Dermatol 31(5) 545∼ 554, 2019)

재한 중국인 유학생의 실패공포와 내현적 자기애가 학업지연행동에 미치는 영향

곽이문(Guo Yiwen),허비비( Xu Feifei),임현수(Lim Hyunsu),강진령(Kang, Jinryung) 학습자중심교과교육학회 2018 학습자중심교과교육연구 Vol.18 No.23

본 연구는 재한 중국인 유학생의 학업지연행동에 영향을 미치는 개인 내적 요인에 대해 탐색하는데 목적을 갖고 있다. 이를 위해 2016년 2월부터 3월에 걸쳐 서울특별시에 소재한 4년제 2개 대학의 중국인 유학생 214명을 대상으로 설문조사를 실시하 였으며, 회수된 자료는 SPSS 23.0을 이용하여 빈도분석 및 Pearson상관분석, 성별에 따른 차이를 보기위한 t-검증, 그리고 다중회귀분석을 실시하였다. 연구결과는 다음과 같다. 첫째, 재한 중국인 유학생의 실패공포, 내현적 자기애와 학업지연행동은 유의한 정적 상관을 나타냈다. 둘째, 재한 중국인 유학생의 실패공포와 내현적 자기애는 학업지연행동에 정적 영향을 미치는 것으로 나타났다. 셋째, 재한 중국인 여학생이 남학생보다 실패공포, 내현적 자기애, 그리고 학업지연행동의 정도가 전체적으로 높은 결과를 나타냈다. 이와 같은 결과는 실패공포와 내현적 자기애가 학업지연행동에 어떤 영향을 미치는지 과정을 설명하고 성별에 따른 차이를 확인하였다는 것, 그리고 중국인 유학생의 심리적 특성에 맞는 적합한 교육 및 학업상담을 제공하는 기초자료로써 본 연구의 의의가 있다. The purpose of the study is to find out the effects of fear of failure and convert narcissism on academic procrastination among Chinese students who study in Korean university. For this purpose, 214 Chinese student’s survey results were collected from whom studying at four-year universities two in Seoul. And statistical analysis was carried out using SPSS 23.0. From the beginning, both independent sample T-test and Pearson Correlation Coefficient (PCC) have been utilized to study the gender differences and correlation of fear of failure, covert narcissism of Chinese students, respectively. At the end, multiple regression analysis is used to validate the impact from fear of failure and covert narcissism on academic procrastination. The results of the study are as follows: Firstly, the research results indicates the meaningful correlations among fear of failure, convert narcissism and academic procrastination of Chinese students. Secondly, the research results of impact from fear of failure and convert narcissism on academic procrastination of Chinese students shows that the fear of failure and the covert narcissism both have positively impact on academic procrastination. Last but not least, according to the gender difference study, following meaningful results are achieved: Female students tend to have slightly heavier behavior in academic procrastination than male students and there are relatively more female students than male students in each sub factors of fear of failure and covert narcissism. based on these results, the importance and necessary is obvious to conduct a research according impact on academic procrastination from fear of failure and convert narcissism. And this study is meaningful as a basic data to provide appropriate education and psychological counseling for Chinese students who study in Korea.

Facile Fabrication of Superhydrophobic Cellulose/Fe2O3-STA Film with Nanoflower Morphologies for Heavy Oil Removal

Chang-Lian Xu,Shiyi Wang,Lu Zhou,Yiwen Bi,Gang Yang,Jun Wu,Xiaohong Zhang 한국섬유공학회 2022 Fibers and polymers Vol.23 No.10

Heavy oils induced water pollutions are difficult to be eliminated due to the oils located under water. Herein, wefabricated superhydrophobic cellulose film with nanoflower structures via a Facile method to eliminate heavy oil from water. Cellulose films were in-situ modified with Fe2O3 and stearic acid (STA) for superhydrophobic modification. Thecorresponding superhydrophobic cellulose/Fe2O3-STA film has water contact angle of 155.5 º and sliding angle of 5.5 º, andcan maintains its superhydrophobicity when it is immersed in water. The film exists excellent self-cleaning property, and thedusts on the film could be easily swept away by running water drops. The film was further applied to separate heavy oil/watermixture with separation efficiency of 99.37 %, and the separation efficiency was maintained after 20 separation cycles aswell. The film can also be utilized to absorb small heavy oil drops under water. Thus, we not only develop a simple way toproduce superhydrophobic cellulose based films, but also provide superhydrophobic materials to solve water pollutioncaused by heavy oil.

3D-quantitative structure–activity relationship and antiviral effects of curcumin derivatives as potent inhibitors of infl uenza H1N1 neuraminidase

Yanni Lai,Yiwen Yan,Shanghui Liao,Yun Li,Yi Ye,Ni Liu,Fang Zhao,Peiping Xu 대한약학회 2020 Archives of Pharmacal Research Vol.43 No.5

Curcumin derivatives have been shown to inhibitreplication of human infl uenza A viruses (IAVs). However, itis not clear whether curcumin and its derivatives can inhibitneuraminidase (NA) of influenza virus. In this study, ameaningful 3D quantitative structure–activity relationshipmodel (comparative molecular fi eld analysis R 2 = 0.997,q 2 = 0.527, s = 0.064, F = 282.663) was built to understandthe chemical–biological interactions between their activitiesand neuraminidase. Molecular docking was used to predictbinding models between curcumin derivatives and neuraminidase. Real-time polymerase chain reactions showed thatthe fi ve active curcumin derivatives might have direct eff ectson viral particle infectivity in H1N1-infected lung epithelial(MDCK) cells. Neuraminidase activation assay showed thatfi ve active curcumin derivatives decreased H1N1-inducedneuraminidase activation in MDCK cells. Indirect immunofluorescence assay indicated that two active curcuminderivatives (tetramethylcurcumin and curcumin) down-regulatedthe nucleoprotein expression. Curcumin inhibited IAVin vivo. The therapeutic mechanism of curcumin in the treatmentof infl uenza viral pneumonia is related to improvingthe immune function of infected mice and regulating secretionof tumor necrosis-α, interleukin-6, and interferon-γ. These results indicate that curcumin derivatives inhibit IAVby blocking neuraminidase in the cellular model and curcuminalso has anti-IAV activity in the animal model.

Electroless Cu/Ni Plating on Graphite Flake and the Effects to the Properties of Graphite Flake/Si/Al Hybrid Composites

Ying Huang,Xuanyi Peng,Yiwen Yang,Haiwei Wu,Xu Sun,Xiaopeng Han 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.5

Proper process and parameter were investigated to coat Cu or Ni on graphite fl ake (G f ) by electroless plating. Microstructuralcharacterization indicated that the Cu/Ni was coated on the G f uniformly and comprehensively. Then aluminum matrixcomposites reinforced with Si and graphite were fabricated by a unique vacuum gas pressure infi ltration. The thermal conductivityand mechanical properties of the composites, both with and without Cu or Ni coating layers on the graphite surface,have been studied. The obtained results indicated that the mechanical property of the Cu or Ni coated G f /Si/Al compositesdramatically increased, as compared with the non-coated G f /Si/Al composite. In the meantime, Cu or Ni coated G f provedto have better wettability and interfacial bonding with the aluminum matrix, which were expected to be a highly sustainableand dispersible reinforcement for metal matrix composites.

Acupuncture for Osteoporosis: a Review of Its Clinical and Preclinical Studies

Tian Yimiao,Wang Lili,Xu Tianshu,Li Rui,Zhu Ruyuan,Chen Beibei,Zhang Hao,Xia Bingke,Che Yiwen,Zhao Dandan,Zhang Dongwei 사단법인약침학회 2022 Journal of Acupuncture & Meridian Studies Vol.15 No.5

Acupuncture has gained growing attention in the management of osteoporosis (OP). However, a comprehensive review has not yet been conducted on the efficacy and challenges of acupuncture in preliminary research and clinical trials. Therefore, an extensive literature search was conducted using electronic databases, including PubMed (www.ncbi.nlm.nih.gov/pubmed), CNKI (www.cnki.net), and Web of Science, for studies published from the beginning of 2000 to the end of May 2022. Combinations of synonyms for OP, acupuncture, traditional Chinese medicine, clinical trial, preclinical study, and animal experiments were searched. A total of 290 papers were consulted, including 115 reviews, 109 clinical observations, and 66 preclinical studies. There is accumulating evidence to support the beneficial role of acupuncture in preserving bone quality and relieving clinical symptoms based on clinical and preclinical investigations. The top ten most commonly used acupoints are BL23, ST36, BL20, BL11, CV4, GV4, SP 6, KI3, BL18, and GB39. The underlying mechanisms behind the benefits of acupuncture may be linked with the regulation of the hypothalamic-pituitary-gonadal (adrenal) axis and activation of the Wnt/β-catenin and OPG/RANKL/RANK signaling pathways. In summary, strong evidence may still come from prospective and well-designed clinical trials to shed light on the potential role of acupuncture in preserving bone loss. Future investigations are needed to explore the potential underlying mechanisms, long-term clinical efficacy, and compliance of acupuncture in OP management.

Fast Depth Video Coding with Intra Prediction on VVC

( Hongan Wei ),( Binqian Zhou ),( Ying Fang ),( Yiwen Xu ),( Tiesong Zhao ) 한국인터넷정보학회 2020 KSII Transactions on Internet and Information Syst Vol.14 No.7

In the stereoscopic or multiview display, the depth video illustrates visual distances between objects and camera. To promote the computational efficiency of depth video encoder, we exploit the intra prediction of depth videos under Versatile Video Coding (VVC) and observe a diverse distribution of intra prediction modes with different coding unit sizes. We propose a hybrid scheme to further boost fast depth video coding. In the first stage, we adaptively predict the HADamard (HAD) costs of intra prediction modes and initialize a candidate list according to the HAD costs. Then, the candidate list is further improved by considering the probability distribution of candidate modes with different CU sizes. Finally, early termination of CU splitting is performed at each CU depth level based on the Bayesian theorem. Our proposed method is incorporated into VVC intra prediction for fast coding of depth videos. Experiments with 7 standard sequences and 4 Quantization parameters (Qps) validate the efficiency of our method.