High-performance expanded graphite from flake graphite by microwave-assisted chemical intercalation process

Qun Wei,Lei Xu,Zhimeng Tang,Zhangbiao Xu,Cheng Xie,Lirong Guo,Wei Li 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.122 No.-

Herein, a facile preparation method with characteristics of energy-saving, efficient and environmentallyfriendly is proposed. Firstly, GICs (Graphite Intercalation Compounds) were synthesized by microwaveassisted hydrothermal method using flake graphite (FG) as raw material, H2SO4, and K2S2O8 as oxidativeintercalations by microwave-assisted oxidation for 5 min, and then EG was prepared from obtained GICsby microwave irradiation for 40 s under the microwave power of 800 W, and the effect of different processconditions on EG expansion volume (EV) was studied. The results show that EG with a good expansioncan be rapidly prepared by microwave irradiation, and the EV value can reach 455 mL /g under theoptimal conditions. In particular, the prepared EG has a high graphitization degree with less structuraldamage, exihibiting good industrial application prospects. The mechanism of K2S2O8 oxidation and graphiteexpansion under microwave irradiation was analyzed. In adition, flexible graphite foil papers preparedwith the obtained EG exhibit good electrical conductivity and thermal properties. The as preparedEG material shows an efficient adsorption of hydraulic oil and vegetable oil and excellent flame retardantperformance. This preparation method is green, low cost, and safe, and can be used for the efficient batchpreparation of EG.

Breviscapine Ameliorates Fear Extinction and Anxiety in BALB/cJ Mice

Wei Liang(Wei Liang),Jing Huang(Jing Huang),Shuya Yang(Shuya Yang),Peng Huang(Peng Huang),Jun Chen(Jun Chen),Chen Chen(Chen Chen),Qun Yang(Qun Yang),Fengzhan Li(Fengzhan Li) 대한신경정신의학회 2023 PSYCHIATRY INVESTIGATION Vol.20 No.3

Objective In this research, the influence of breviscapine on anxiety, fear elimination, and aggression and the potential mechanism was investigated. Methods Anxiety and locomotion were analyzed by elevated plus maze and open field test in mice. Bussey-Saksida Mouse Touch Screen Chambers were used to perform fear conditioning. Territorial aggression was assessed by resident intruder test. Protein levels were evaluated by Western blot. Breviscapine improved fear-extinction learning in BALB/cJ mice. Results Breviscapine at 20-100 mg/kg increased center cross number, total distance traveled, and velocity in a dose-dependent manner. On the other hand, breviscapine at 20-100 mg/kg decreased the immobility time in open field test. In addition, breviscapine at 20-100 mg/kg increased the ratio of time on the open arm, time on the distal parts of the open arm, and total distance traveled in elevated plus maze. Breviscapine at 100 mg/kg increased the average attack latency and decreased the number of attacks over the last 3 days of resident intruder test. In hippocampus, protein levels of postsynaptic density protein-95 and synaptophysin were elevated by breviscapine at these three doses. Conclusion The administration of breviscapine alleviates fear extinction, anxiety, and aggression, while increases locomotor in a dose-dependent manner, which might be associated with its influence on synaptic function.

Analysis of Indoleamine 2-3 Dioxygenase (IDO) and EGFR Co-expression in Breast Cancer Tissue by Immunohistochemistry

Bi, Wei-Wei,Zhang, Wei-Hua,Yin, Gui-Hua,Luo, Hong,Wang, Shou-Qin,Wang, Hongran,Li, Chao,Yan, Wei-Qun,Nie, De-Zhi Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.14

Background: To determine the amount of co-expression of IDO and EGFR in breast cancer patients. Materials and Methods:In order to obtain the distribution of co-expression of IDO and EGFR in breast cancer, we tested 110 breast cancer paraffin tissue blocks with immunohistochemical methods. Then we investigated the relationship between the diagnostic and pathologic characteristics (tumor size, lymph node status, histologic grade, the gene expression of ER, PR, HER2, p53, Ki67 and PCNA) with the situation of co-expression of IDO and EGFR by reviewing the medical records of 32 breast cancer patients. Results: Among 110 breast cancers, 32 cases demonstrated IDO and EGFR co-expression (29.1%), IDO and EGFR synchronous co-expression being found in 19.1% and asynchronous in 10.0%. Conclusions: IDO and EGFR were co-expressed in breast cancer, including synchronous and asynchronous co-expression. The results suggest that considering IDO and EGFR as two indicators for breast cancer treatment or prognosis analysis provides a potential option of individual treatment for the portion of breast cancer patients with co-expression of IDO and EGFR.

Development of a Wireless Health Monitoring System for Measuring Core Body Temperature from the Back of the Body

Wei, Qun,Park, Hee-Joon,Lee, Jyung Hyun Hindawi 2019 Journal of healthcare engineering Vol.2019 No.-

<P>In this paper, a user-friendly and low-cost wireless health monitoring system that measures skin temperature from the back of the body for monitoring the core body temperature is proposed. To measure skin temperature accurately, a semiconductor-based microtemperature sensor with a maximum accuracy of ±0.3°C was chosen and controlled by a high-performance/low-power consumption Acorn-Reduced Instruction Set Computing Machine (ARM) architecture microcontroller to build the temperature measuring device. Relying on a 2.4 GHz multichannel Gaussian frequency shift keying (GFSK) RF communication technology, up to 100 proposed temperature measuring devices can transmit the data to one receiver at the same time. The shell of the proposed wireless temperature-measuring device was manufactured via a 3D printer, and the device was assembled to conduct the performance tests and <I>in vivo</I> experiments. The performance test was conducted with a K-type temperature sensor in a temperature chamber to observe temperature measurement performance. The results showed an error value between two devices was less than 0.1°C from 25 to 40°C. For the <I>in vivo</I> experiments, the device was attached on the back of 10 younger male subjects to measure skin temperature to investigate the relationship with ear temperature. According to the experimental results, an algorithm based on the curve-fitting method was implemented in the proposed device to estimate the core body temperature by the measured skin temperature value. The algorithm was established as a linear model and set as a quadratic formula with an interpolant and with each coefficient for the equation set with 95% confidence bounds. For evaluating the goodness of fit, the sum of squares due to error (SSE), <I>R</I>-square, adjusted <I>R</I>-square, and root mean square error (RMSE) values were 33.0874, 0.0212, 0.0117, and 0.3998, respectively. As the experimental results have shown, the mean value for an error between ear temperature and estimated core body temperature is about ±0.19°C, and the mean bias is 0.05 ± 0.14°C when the subjects are in steady status.</P>

Effects of postharvest chilling and heating treatments on the sensory quality and antioxidant system of daylily flowers

Wei Liu,Juhua Zhang,Qun Zhang,Yang Shan 한국원예학회 2018 Horticulture, Environment, and Biotechnology Vol.59 No.5

Temperature is the most important factor that affects the metabolism of harvested plants. The aim of this study was to investigate the influence and mechanisms of temperature on the antioxidant system in fresh-cut daylily flowers (Hemerocallis lilioasphodelus L.; used for food consumption) during storage. Daylily flowers were harvested and immediately treated by either chilling at 5 °C for 5 days, or by heating with 50 °C hot air for 5 min, then stored at 20 °C for 5 days. The chilling and heating treatments maintained the organoleptic quality and enhanced the antioxidant system of cut daylily flowers. However, different reactions of the antioxidant system were observed under the different temperature treatments. The chilling treatment dramatically enhanced the activities of superoxide dismutase, ascorbate peroxidase, peroxidase, and phenylalanine ammonia lyase, while it decreased the activity of lipoxygenase. Meanwhile, the heating treatment enhanced catalase activity and decreased polyphenol oxidase activity. In addition, the heating treatment reduced the O2− production rate and H2O2 content compared to the control. Changes in membrane permeability, total phenolic content, total flavonoid content, and diphenyl-1-picrylhydrazyl clearance activity showed no significant difference between the chilling and heating treatments, owning to the steady content of phenolic and flavonoid compounds and the delay in the generation of quinones. Thus, our results indicate that cold and heat treatments can impact the preservation of harvested daylilies used for food consumption.

Rapid reactive synthesis of Ti₂AlC-TiB₂ composites by spark plasma sintering

Wei-Bing Zhou,Bing-Chu. Mei,Jiao-Qun. Zhu 한양대학교 세라믹연구소 2009 Journal of Ceramic Processing Research Vol.10 No.1

In this paper, dense Ti₂AlC/TiB₂ composites were successfully fabricated by a rapid reactive sintering process by a spark plasma sintering (SPS) technique using Ti, Al, TiC and B₄C powders. The microstructure, flexural strength and fracture toughness of the composites were investigated. The experimental results indicate that the Vickers hardness increased with an increase in TiB₂ content. The maximum flexural strength (573 MPa) and fracture toughness (6.2 MPa·m½) were achieved through the addition of 10 vol%TiB₂. The incorporation of a TiB₂ phase makes a positive contribution to its electrical conductivity. In this paper, dense Ti₂AlC/TiB₂ composites were successfully fabricated by a rapid reactive sintering process by a spark plasma sintering (SPS) technique using Ti, Al, TiC and B₄C powders. The microstructure, flexural strength and fracture toughness of the composites were investigated. The experimental results indicate that the Vickers hardness increased with an increase in TiB₂ content. The maximum flexural strength (573 MPa) and fracture toughness (6.2 MPa·m½) were achieved through the addition of 10 vol%TiB₂. The incorporation of a TiB₂ phase makes a positive contribution to its electrical conductivity.

Electrical signal characteristics of conductive asphalt concrete in the process of fatigue cracking

Qun Yang,Ping Wang,Xu Li,Hong-Wei Zhang 국제구조공학회 2014 Smart Structures and Systems, An International Jou Vol.14 No.3

As a kind of intelligent materials, conductive asphalt concrete has a broad application prospect including melting ice and snow on the pavement, closing cracks in asphalt concrete, sensing pavement damage, and so on. Conductive pavement will be suffered from fatigue failure as conventional pavement in the process of service, and this fatigue damage of internal structure can be induced by electrical signal output. The characteristics of electrical signal variation of conductive asphalt concrete in the process of fatigue cracking were researched in this paper. The whole process was clearly divided into three stages according to resistance changes, and the development of fatigue damage wasn\'t obvious in stage I and stage II, while in stage III, the synchronicity between the resistance and damage began to appear. Thus, fatigue damage variable D and initial damage value D0 represented by the functions of resistance were introduced in stage III. After calculating the initial damage value D0 under different stress levels, it was concluded that the initial damage value D0 had no noticeable change, just ranged between 0.24 and 0.25. This value represented a critical point which could be used to inform the repair time of early fatigue damage in the conductive asphalt pavement.

Part 2. Major Power Interactions And The Korean Peninsula : China`s "Open-Door" Policy and the Korean Peninsula -Chapter 7

( Wei Qun Gu ) 연세대학교 동서문제연구원 1990 East and West Studies Series Vol.14 No.-

Exploring Actinide Chemistry through Synchrotron Radiation Techniques

( Wei-qun Shi ) 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-

Synchrotron radiation (SR) based techniques have been utilized with increasing frequency in the past several decades to explore the brilliant and challenging actinide chemistry. This trend is much driven by the needs to probe the electronic structure and chemical speciation as well as mapping of actinides in various media with high sensitivity. In this talk, recent research progresses on actinide related materials by means of various SR techniques were selectively highlighted and summarized, with the emphasis on X-ray absorption spectroscopy, X-ray diffraction and scattering spectroscopy, which are powerful tools to characterize actinide microstructures. The considerations for design of dedicated beam-line for radiochemistry research in High Energy Photon Source (HEPS) will be also introduced.

2010 Asian WTO Research Network (AWRN) Seoul Meeting : China`s Strategy and Practice with Free Trade Area

( Wei Qun Yao ),( Bo Chen ) 고려대학교 법학연구원 2010 Korea University Law Review Vol.8 No.-