Tribological performances of copper perrhenate/graphene nanocomposite as lubricating additive under various temperatures

Junhai Wang,Weipeng Zhuang,Tingting Yan,Wenfeng Liang,Ting Li,Lixiu Zhang,Xiaoyi Wei 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.100 No.-

Herein, copper perrhenate (Cu(ReO4)2) was synthesized using a micro-emulsion method and adhered tographene (Gr) using an ultrasonic process. Then, the as-prepared Cu(ReO4)2/Gr composite was added intothe synthetic oil as a lubricant additive with the help of ionic liquid to achieve enhanced dispersionstability within the base oil. The tribological performances of the Cu(ReO4)2/Gr additive wereinvestigated using four-ball tests and the ball-on-disk reciprocating configuration under varioustemperatures. The potential lubrication mechanisms of the Cu(ReO4)2/Gr additive were performed usinga series of characterization methods including XRD, Raman, SEM-EDS, TEM, DSC/TG, and XPS. The resultsof four-ball tests at room temperature indicated that the Cu(ReO4)2/Gr additive could substantiallyimprove the tribological performances of the base oil. The smallest coefficient of friction (COF) and wearscar diameter (WSD) values were 0.068 and 495 mm, respectively, when 0.05 wt% of Cu(ReO4)2/Gr wasadded. Additionally, the graphene accelerated friction-induced heat transfer, which led to decreasedfriction and wear. The results of reciprocating friction experiments at elevated temperatures revealedthat the Cu(ReO4)2/Gr additive had excellent friction-reduction properties when the temperature washigh. This could be attributed to the generation of a protective layer containing tribo-oxides from thealloy, some residual carbides and copper perrhenate induced by friction heat and stress. This protectivelayer was uniformly and stably covered on the worn surface, which could effectively alleviate directcontact between the rubbing pair.

Cloud Service Trust Model and Its Application Research Based on the Third Party Certification

Haiyong Xu,Junhai Ma,Lei Li,Xueli Zhan 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.7

With the development of computer and Internet technology, the concept of cloud computing has been accepted by related industries worldwide, especially on the development in the field of telecommunications and electronic commerce field rapidly. This paper introduces the meaning, characteristics of cloud computing, advantages and service pattern, and with the introduction of technology development present situation and the crisis of confidence by the cloud computing, describes the safety bottleneck problems faced in the promotion process of the cloud calculation. This paper presents cloud service trust model based on third party certification, and then through the analysis and study of the model, describes the security situation in the presence of third party certification body under the condition of cloud services, the Nash equilibrium solution; and the general cloud computing and e-commerce trust system were compared, the third party authentication mechanism can effectively play its advantages in supervision, has the huge influence of credit risk rating on its own transactions and future credit decision.

The Analysis of Agricultural Output in Port SD Province Based on System Dynamics

Jianliang Liu,Junhai Ma,Yi Tian 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.9

In order to know various factors affecting agricultural development in Shandong Province, this paper uses system dynamics model, modeling on agricultural output system in Shandong Province .It analyses how population growth, household consumption, the existing agricultural resources as well as GDP of Shandong Province affect the agricultural output, and uses Vensim software to make algorithm implemented. It analyses the effects of changed factors on agricultural output, and helps for government to make the agricultural development policy.

Polyethyleneimine-functionalized phenolphthalein-based cardo poly (ether ether ketone) membrane for CO2 separation

Yunwu Yu,Junhai Wang,Yan Wang,Wenhao Pan,Changwei Liu,Peng Liu,Lianjie Liang,Changwei Xu,Yunxue Liu 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.83 No.-

Phenolphthalein-based cardo poly(ether ether ketone) (PEEKWC)/polyethyleneimine (PEI) crosslinkingmembranes were prepared by solution casting followed by solution reaction at room temperature. Theeffects of reaction time and PEI content on the membrane structure and gas separation performanceswere investigated. Light transmittance measure and AFM evidenced the relationship between themicrophase separation in PEEKWC-PEI membranes and reaction time. The CO2 permeability increasedwith the PEI content, while the N2 and CH4 permeability remained nearly constant. This result indicatedthat only CO2 was transported by the solution–diffusion mechanism and also that PEI exhibited a positivecontribution as afixed carrier for CO2 facilitated transport. Meanwhile the PEEKWC-PEI crosslinkingmembranes showed higher selectivities than the pure PEEKWC membrane. The highest CO2/N2 and CO2/CH4 selectivities were about 131 and 122 increasing from 33 and 30, respectively. The crosslinkingstructure of membranes improved the CO2 permeability stability.

The Important Anti-Apoptotic Role and Its Regulation Mechanism of PTTG1 in UV-Induced Apoptosis

Lai, Yongqing,Xin, Dianqi,Bai, Junhai,Mao, Zebin,Na, Yanqun Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.6

Pituitary tumor transforming gene (PTTG1) is widely detected in many tumors. Increasing evidence reveals that PTTG1 is associated with cell proliferation, cellular transformation and apoptosis. However, the functions of PTTG1, especially its role in DNA damage-induced apoptosis, remain largely unclear. In this report, we used UV irradiation to induce apoptosis in HeLa cells to examine the role of PTTG1 in UV-induced apoptosis by RNAi-mediated knockdown and overexpression of PTTG1. RNAi-mediated knockdown of PTTG1 expression increased and overexpression of PTTG1 decreased the UV-induced apoptosis. Furthermore, UV irradiation decreased PTTG1 mRNA and protein expression. These effects were found to be mediated by JNK pathway. Therefore, PTTG1 had an important anti-apoptotic role in UV-induced apoptosis and this role was mediated by JNK pathway. These results may provide important information for understanding the exact role and the regulation mechanism of PTTG1 in UV-induced apoptosis.

Risk Factors for Duodenal Stump Leakage after Laparoscopic Gastrectomy for Gastric Cancer

Gu, Lihu,Zhang, Kang,Shen, Zefeng,Wang, Xianfa,Zhu, Hepan,Pan, Junhai,Zhong, Xin,Khadaroo, Parikshit Asutosh,Chen, Ping The Korean Gastric Cancer Association 2020 Journal of gastric cancer Vol. No.

Purpose: Duodenal stump leakage (DSL) is a potentially fatal complication that can occur after gastrectomy, but its underlying risk factors are unclear. This study aimed to investigate the risk factors and management of DSL after laparoscopic radical gastrectomy for gastric cancer (GC). Materials and Methods: Relevant data were collected from several prospective databases to retrospectively analyze the data of GC patients who underwent Billroth II (B-II) or Rouxen-Y (R-Y) reconstruction after laparoscopic gastrectomy from 2 institutions (Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, and HwaMei Hospital, University of Chinese Academy of Sciences). The DSL risk factors were analyzed using univariate and multivariate analysis regression. Results: A total of 810 patients were eligible for our analysis (426 with R-Y, 384 with B-II with Braun). Eleven patients had DSL (1.36%). Body mass index (BMI), elevated preoperative C-reactive protein (CRP) level, and unreinforced duodenal stump were the independent risk factors for DSL. DSL was diagnosed in 2-12 days, with a median of 8 days. Seven patients received conservative treatment, 3 patients received puncture treatment, and only 1 patient required reoperation. All patients recovered successfully after treatment. Conclusions: The risk factors of DSL were BMI ≥24 kg/㎡, elevated preoperative CRP level, and unreinforced duodenal stump. Nonsurgical treatments for DSL are preferred.

Risk Factors for Duodenal Stump Leakage after Laparoscopic Gastrectomy for Gastric Cancer

Lihu Gu,Kang Zhang,Zefeng Shen,Xianfa Wang,Hepan Zhu,Junhai Pan,Xin Zhong,Parikshit Asutosh Khadaroo,Ping Chen 대한위암학회 2020 Journal of gastric cancer Vol. No.

Purpose: Duodenal stump leakage (DSL) is a potentially fatal complication that can occur after gastrectomy, but its underlying risk factors are unclear. This study aimed to investigate the risk factors and management of DSL after laparoscopic radical gastrectomy for gastric cancer (GC). Materials: and Methods Relevant data were collected from several prospective databases to retrospectively analyze the data of GC patients who underwent Billroth II (B-II) or Roux-en-Y (R-Y) reconstruction after laparoscopic gastrectomy from 2 institutions (Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, and HwaMei Hospital, University of Chinese Academy of Sciences). The DSL risk factors were analyzed using univariate and multivariate analysis regression. Results: A total of 810 patients were eligible for our analysis (426 with R-Y, 384 with B-II with Braun). Eleven patients had DSL (1.36%). Body mass index (BMI), elevated preoperative C-reactive protein (CRP) level, and unreinforced duodenal stump were the independent risk factors for DSL. DSL was diagnosed in 2–12 days, with a median of 8 days. Seven patients received conservative treatment, 3 patients received puncture treatment, and only 1 patient required reoperation. All patients recovered successfully after treatment. Conclusions: The risk factors of DSL were BMI ≥24 kg/m2, elevated preoperative CRP level, and unreinforced duodenal stump. Nonsurgical treatments for DSL are preferred.

90-fs diode-pumped Yb:CLNGG laser mode-locked using single-walled carbon nanotube saturable absorber.

Zhang, Yuangeng,Petrov, Valentin,Griebner, Uwe,Zhang, Xingyu,Choi, Sun Young,Gwak, Ji Yoon,Rotermund, Fabian,Mateos, Xavier,Yu, Haohai,Zhang, Huaijin,Liu, Junhai Optical Society of America 2014 Optics express Vol.22 No.5

<P>A diode-pumped Yb:CLNGG laser is mode-locked with a single-walled carbon nanotube saturable absorber (SWCNT-SA) for the first time. Pulse durations as short as 90 fs are obtained at ~1049 nm with 0.4% output coupler, the shortest pulses to our knowledge for a diode-pumped 1-?m laser applying SWCNTs as saturable absorber. Using 3% output coupler, the maximum average output power reached 90 mW at a repetition frequency of 83 MHz.</P>