Microstructure and Abrasive Wear Properties of Fe-Cr-C Hardfacing Alloy Cladding Manufactured by Gas Tungsten Arc Welding (GTAW)

Jie-Hao Chen,Chih-Chun Hsieh,Pei-Shing Hua,Chia-Ming Chang,Chi-Ming Lin,Paxon Ti-Yuan Wu,Weite Wu 대한금속·재료학회 2013 METALS AND MATERIALS International Vol.19 No.1

A series of Fe-Cr-C hardfacing alloys is deposited by gas tungsten arc welding and subjected to abrasive wear testing. Pure Fe with various amounts of CrC (Cr:C=4:1) powders are mixed as the fillers and used to deposit hardfacing alloys on low carbon steel. Depending on the various CrC additions to the alloy fillers,the claddings mainly contain hypoeutectic, near eutectic, or hypereutectic microstructures of austenite γ-Fe phase and (Cr,Fe)7C3 carbides on hardfacing alloys, respectively. When 30% CrC is added to the filler, the finest microstructure is achieved, which corresponds to the γ-Fe+(Cr,Fe)7C3 eutectic structure. With the addition of 35% and 40% CrC to the fillers, the results show that the cladding consists of the massive primary (Cr,Fe)7C3 as the reinforcing phase and interdendritic Fe+(Cr,Fe)7C3 eutectics as the matrix. The (Cr,Fe)7C3 carbide-reinforced claddings have high hardness and excellent wear resistance under abrasive wear test conditions. Concerning the abrasive wear feature observable on the worn surface, the formation and fraction of massive primary (Cr,Fe)7C3 carbides predominates the wear resistance of hardfacing alloys. Abrasive particles result in continuous plastic grooves when the cladding has primary γ-Fe phase in a hypoeutectic structure.

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.

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.

Sex Differences in Early and Late Recurrence after Liver Resection of Hepatocellular Carcinoma (A Multicenter Study from China)

( Jiong-jie Yu ),( Ju-dong Li ),( Xin-fei Xu ),( Zhen-li Li ),( Jun Han ),( Hao Xing ),( Han Wu ),( Jian-hong Zhong ),( Yi-sheng Huang ),( Ya- Hao Zhou ),( Ting-hao Chen ),( Hong Wang ),( Wei-min Gu ) 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: There is a striking sex difference in the incidence of hepatocellular carcinoma (HCC), with a strong predominance for males. However, the impact of sex on the incidence of recurrence after curative resection of HCC remains controversial. Herein, we assess sex differences in the risks of recurrence and mortality for patients undergone curative resection of HCC. Methods: Data from 1,435 HCC patients undergone curative resection (1,228 males and 207 females) between 2004 and 2014 at five institutions in China were retrospectively analyzed. Patients’ baseline characteristics, operative variables, and rates of early recurrence (≤ 2 years after resection), late recurrence (> 2 years) and cancer-specific mortality (CSM) were evaluated and compared. Multivariable competing-risks regression analyses were performed to identify predictors associated with CSM, early and late recurrence. Results: The early recurrence rates between males and females were similar (43.3% vs. 42.0%, P=0.728), but the late recurrence and CSM rates in males were higher when compared to females (17.2% vs. 11.2%, P=0.044; 42.8% vs. 34.3%, P=0.022). Multivariable competing-risks regression analyses revealed no sex difference in early recurrence; however, males had significantly higher late recurrence rate [hazard ratio (HR), 1.752; 95% CI, 1.145-2.682; P=0.010] and CSM rate (HR, 1.307; 95% CI, 1.015-1.683; P=0.038) than females. Conclusions: Males had significantly higher late recurrence and CSM rates after curative resection of HCC than females. This suggests postoperative surveillance for HCC recurrence be varied by sex, especially for patients without recurrence at 2 years after resection.

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.

Enhanced Performance of Solution‐Processed TESPE‐ADT Thin‐Film Transistors

Chen, Liang‐,Hsiang,Hu, Tarng‐,Shiang,Huang, Peng‐,Yi,Kim, Choongik,Yang, Ching‐,Hao,Wang, Juin‐,Jie,Yan, Jing‐,Yi,Ho, Jia‐,Chong,Lee, Cheng‐,Chung,Chen WILEY‐VCH Verlag 2013 Chemphyschem Vol.14 No.12

<P><B>Abstract</B></P><P>A solution‐processed anthradithiophene derivative, 5,11‐bis(4‐triethylsilylphenylethynyl)anthradithiophene (TESPE‐ADT), is studied for use as the semiconducting material in thin‐film transistors (TFTs). To enhance the electrical performance of the devices, two different kinds of solution processing (spin‐coating and drop‐casting) on various gate dielectrics as well as additional post‐treatment are employed on thin films of TESPE‐ADT, and <I>p</I>‐channel OTFT transport with hole mobilities as high as ∼0.12 cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP> are achieved. The film morphologies and formed microstructures of the semiconductor films are characterized in terms of film processing conditions and are correlated with variations in device performance.</P>

The Compact Pulsed Hadron Source: A Design Perspective

Jie Wei,Huaibi Chen,Cheng Cheng,Qiang Du,Zhe Feng,Xialin Guan,Xiaoxue Han,Tuchen Huang,Renkai Li,Chun K. Loong,Beibei Shao,Chuanxiang Tang,Qingzi Xing,Yigang Yang,Hao Zha,Huayi Zhang,Shuxin Zheng,Bin 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.56 No.61

During the past decades, large-scale national neutron sources have been developed in Asia, Europe,and North America. Complementing such efforts, compact hadron beam complexes and neutron sources intended to serve primarily universities and industrial institutes have been proposed,and some have recently been established. Responding to the demand in China for pulsed neutron/proton-beam platforms that are dedicated to fundamental and applied research for users in multiple disciplines from materials characterization to hadron therapy and radiography to accelerator-driven sub-critical reactor systems (ADS) for nuclear waste transmutation, we have initiated the construction of a compact, yet expandable, accelerator complex-the Compact Pulsed Hadron Source (CPHS). It consists of an accelerator front-end (a high-intensity ion source, a 3-MeV radio-frequency quadrupole linac (RFQ), and a 13-MeV drift-tube linac (DTL)), a neutron target station (a beryllium target with solid methane and room-temperature water moderators/reflector),and experimental stations for neutron imaging/radiography, small-angle scattering, and proton irradiation. In the future, the CPHS may also serve as an injector to a ring for proton therapy and radiography or as the front end to an ADS test facility. In this paper, we describe the design of the CPHS technical systems and its intended operation.

Surgical Treatment for Early Esophageal Squamous Cell Carcinoma

Chen, Shao-Bin,Weng, Hong-Rui,Wang, Geng,Yang, Jie-Sheng,Yang, Wei-Ping,Liu, Di-Tian,Chen, Yu-Ping,Zhang, Hao Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.6

More studies are needed to clarify treatments and prognosis of early esophageal squamous cell carcinoma (ESCC). This retrospective study was designed to review the outcome of surgical treatment for early ESCC, evaluate the results of a left thoracotomy for selected patients with early ESCC, and identify factors affecting lymph node metastases and survival. The clinicopathological data of 228 patients with early ESCC who underwent transthoracic esophagectomy with lymphadenectomy without preoperative adjuvant treatment were reviewed. The ${\chi}^2$ test or Fisher's exact test were used to detect factors related to lymph node metastasis. Univariate and multivariate analyses were performed to identify prognostic factors. There were 152 males and 76 females with a median age of 55 years. Two hundred and eight patients underwent a left thoracotomy, and the remaining 20 patients with lymph nodes in the upper mediastinum more than 5 mm in short-axis diameter by computed tomography scan underwent a right thoracotomy. No lymph node metastasis was found in the 18 patients with carcinoma in situ, while lymph node metastases were detected in 1.6% (1/62) of patients with mucosal tumours and 18.2% (27/148) of patients with submucosal tumours. Only 7 patients showed upper mediastinal lymph node metastases in the follow-up. The 5- and 10-year overall survival rates were 81.4% and 70.1%, respectively. Only histologic grade (P<0.001) and pT category (P=0.001) significantly correlated with the presence of lymph node metastases. In multivariate analysis, only histologic grade (P=0.026) and pT category (P=0.008) were independent prognostic factors. A left thoracotomy is acceptable for selected patients with early ESCC. Histologic grade and pT category affected the presence of lymph node metastases and were independent prognostic factors for early ESCC.

Electrochemical Properties of Supercapacitors Using Boron Nitrogen Double-Doped Carbon Nanotubes as Conductive Additive

Hao Hu,Xiaogang Sun,Wei Chen,Jie Wang,Xu Li,Yapan Huang,Chengcheng Wei,Guodong Liang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.7

Carbon nanotubes (CNTs) were doped by ammonium borate as the sources of nitrogen and boron. Under the protection of Ar gas, boron-nitrogen doped CNTs were prepared through nitriding and boronization at high temperature. It is a conductive additive. Then, the obtained CNTs were mixed with activated carbon (AC), SP, sodium dodecyl sulfate (SDS), and cellulose fiber to prepare electrodes. With all the materials, a symmetric electric double-layer supercapacitor (EDLC) was assembled. Next, the materials and electrodes were also characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The factors, chemical connections, and specific surface area of the CNTs were analyzed by X-ray energy spectrum analysis (EDS), X-ray photoelectron spectroscopy (XPS), as well as a specific surface area and porosimetry analyzer (BET). In addition, the electrochemical performances of electric double-layer capacitors were tested with the help of cyclic voltammetry, constant-current charging and discharging, and so on. From the results, we can make a conclusion, that is, both B and N atoms were added into the CNTs and formed bonds successfully with carbon atoms mutually. Besides, the specific surface area is about 1.5 times than that of the CNT. When the charge/discharge current density reaches 50 mA/g, we can find that the mass specific capacitance of the capacitor can run up to 32.19 F/g. Also, we observe that the maximum power density is close to 220 W/kg (700 mA/g), and the energy density can arrive 9.31 Wh/kg (50 mA/g). Based on the impedance test, the electrodes are characterized with low impedance. After 2000 cycles, the boron-nitrogen doped double-layer capacitors maintain a capacitance retention ratio of above 95%. Its power density can still achieve 220 W/kg when the energy density keeps at 3.46 Wh/kg. In other words, the electrochemical performance functions of the electric double-layer capacitors are enhanced while the CNTs serve as the electrodes.

Dynamic self-collision detection and prevention for 2-DOF robot arms using interval-based analysis

Hao Fang,Jie Chen,Lihua Dou 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.8

The problems related to self-collision detection and optimal collision-free trajectory planning for a robot arm subjected to dynamic constraints is investigated. First, a computed-torque method is used to obtain a linearized closed-loop system. For this linearized system,the reference state that the robot arm is capable of reaching is verified through phase plane analysis. This will ensure that the robot arm can be stopped before self-collision occurs. Dynamic constraints are taken into account for a continuous motion of deceleration by calculating the bounds of the commanded force/torques with interval evaluations. When the reference state at t+δt is not valid for selfcollision avoidance, a new feasible state is determined by adhering to an interval-based method which allows decomposition of a complex constrained optimization problem into a simple two-stage optimization problem with relaxed constraints. The optimized feasible state not only secures the robot arm against self-collision but also allows the robot arm to track the original reference trajectory closely. Simulation and experimental results of a 2-dof robot arm show the effectiveness of the proposed interval-based approach.