Structure and Properties of Konjac Glucomannan/Galactoglucomannan Nanofiber Membrane

Yi Yuan,Xin Hong,Ruojun Mu,Jingni Gong,Lin Wang,Rongxun Huang,Jiayu Wu,Yongsheng Ni,Xianhui Wu,Jie Pang 한국고분자학회 2017 Macromolecular Research Vol.25 No.10

Konjac glucomannan (KGM)/galactoglucomannan (GGM) nanofiber membranes were obtained through electrospinning technology. Rheological properties of KGM/GGM solutions were observed by using a rotary rheometer. The apparent morphological, characteristic group and thermal stability of nanofiber membranes were studied through scanning electron microscopy (SEM), Fourier transform infrared spectoscopy (FTIR) and differential scanning calorimeter (DSC) respectively. The physical and mechanical properties were also evaluated. Results revealed that the addition of GGM did not significantly affect the rheological properties of electrospinning solution. Increase in the amount of GGM in the nanofiber membrane resulted in gradual smoothening, uniformity and decrease in the number of nodes. KGM interacts with GGM through hydrogen-bond. Addition of GGM markedly enhanced the thermal stability, physical and mechanical properties of the nanofiber membrane. The study showed that the KGM/GGM nanofiber membrane have good potential for use in developing membrane based materials.

Quasi-Periodic Nanoripples in Graphene Grown by Chemical Vapor Deposition and Its Impact on Charge Transport

Ni, Guang-Xin,Zheng, Yi,Bae, Sukang,Kim, Hye Ri,Pachoud, Alexandre,Kim, Young Soo,Tan, Chang-Ling,Im, Danho,Ahn, Jong-Hyun,Hong, Byung Hee,Ö,zyilmaz, Barbaros American Chemical Society 2012 ACS NANO Vol.6 No.2

<P>The technical breakthrough in synthesizing graphene by chemical vapor deposition methods (CVD) has opened up enormous opportunities for large-scale device applications. To improve the electrical properties of CVD graphene grown on copper (Cu-CVD graphene), recent efforts have focused on increasing the grain size of such polycrystalline graphene films to 100 μm and larger. While an increase in grain size and, hence, a decrease of grain boundary density is expected to greatly enhance the device performance, here we show that the charge mobility and sheet resistance of Cu-CVD graphene is already limited within a single grain. We find that the current high-temperature growth and wet transfer methods of CVD graphene result in quasi-periodic nanoripple arrays (NRAs). Electron-flexural phonon scattering in such partially suspended graphene devices introduces anisotropic charge transport and sets limits to both the highest possible charge mobility and lowest possible sheet resistance values. Our findings provide guidance for further improving the CVD graphene growth and transfer process.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2012/ancac3.2012.6.issue-2/nn203775x/production/images/medium/nn-2011-03775x_0005.eps'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn203775x'>ACS Electronic Supporting Info</A></P>

Graphene–Ferroelectric Hybrid Structure for Flexible Transparent Electrodes

Ni, Guang-Xin,Zheng, Yi,Bae, Sukang,Tan, Chin Yaw,Kahya, Orhan,Wu, Jing,Hong, Byung Hee,Yao, Kui,Ö,zyilmaz, Barbaros American Chemical Society 2012 ACS NANO Vol.6 No.5

<P>Graphene has exceptional optical, mechanical, and electrical properties, making it an emerging material for novel optoelectronics, photonics, and flexible transparent electrode applications. However, the relatively high sheet resistance of graphene is a major constraint for many of these applications. Here we propose a new approach to achieve low sheet resistance in large-scale CVD monolayer graphene using nonvolatile ferroelectric polymer gating. In this hybrid structure, large-scale graphene is heavily doped up to 3 × 10<SUP>13</SUP> cm<SUP>–2</SUP> by nonvolatile ferroelectric dipoles, yielding a low sheet resistance of 120 Ω/□ at ambient conditions. The graphene–ferroelectric transparent conductors (GFeTCs) exhibit more than 95% transmittance from the visible to the near-infrared range owing to the highly transparent nature of the ferroelectric polymer. Together with its excellent mechanical flexibility, chemical inertness, and the simple fabrication process of ferroelectric polymers, the proposed GFeTCs represent a new route toward large-scale graphene-based transparent electrodes and optoelectronics.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2012/ancac3.2012.6.issue-5/nn3010137/production/images/medium/nn-2012-010137_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn3010137'>ACS Electronic Supporting Info</A></P>

Clinical Application of Endoscopic Inguinal Lymph Node Resection after Lipolysis and Liposuction for Vulvar Cancer

Wu, Qiang,Zhao, Yi-Bing,Sun, Zhi-Hua,Ni, Jing,Wu, Yu-Zhong,Shao, Heng-Hua,Qu, Jun-Wei,Huang, Xin-En Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Aim: To examine lymph nodes obtained after lipolysis and liposuction of subcutaneous fat of the inguinal region of female vulvar cancer patients to explore the feasibility of clinical application. Methods: The field of operation was on the basis of the range of the conventional resection of inguinal lymph nodes. We injected lipolysis liquid fanwise, started liposuction after 15-20 minutes; then the subcutaneous fatty tissue was sucked out clearly by suction tube. We selected the first puncture holes located on 2-3 cm part below anterior superior spine, the others respectively being located 3cm and 6cm below the first for puncturing into the skin, imbedding a trocar to intorduce $CO_2$ gas and the specular body, and excise the lymph nodes by ultrasonic scalpel. The surgical field chamber was set with negative pressure drainage and was pressured with a soft saline bag after surgery. Results: A lacuna emerged from subcutaneous of the inguinal region after lipolysis and liposuction, with a wide fascia easily exposed at the bottom where lymph nodes could be readily excised. The number of lymph nodes of ten patients excised within the inguinal region on each side was 4-18. The excised average number of lymph nodes was 11 when we had mature technology. Conclusion: Most of adipose tissue was removed after lipolysis and liposuction of subcutaneous tissue of inguinal region, so that the included lymph nodes were exposed and easy to excise by endoscope. This surgery avoided the large incision of regular surgery of inguinal region, the results indicating that this approach is feasible and safe for used as an alternative technology.

Selective blockade of spinal D2DR by levocorydalmine attenuates morphine tolerance via suppressing PI3K/Akt-MAPK signaling in a MOR-dependent manner

Wen-Ling Dai,Xin-Tong Liu,Yi-Ni Bao,Bing Yan,Nan Jiang,Bo-Yang Yu,Ji-Hua Liu 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

Morphine tolerance remains a challenge in the management of chronic pain in the clinic. As shown in our previous study, the dopamine D2 receptor (D2DR) expressed in spinal cord neurons might be involved in morphine tolerance, but the underlying mechanisms remain to be elucidated. In the present study, selective spinal D2DR blockade attenuated morphine tolerance in mice by inhibiting phosphatidylinositol 3 kinase (PI3K)/serine–threonine kinase (Akt)-mitogen activated protein kinase (MAPK) signaling in a μ opioid receptor (MOR)-dependent manner. Levocorydalmine (l-CDL), which exhibited micromolar affinity for D2DR in D2/CHO-K1 cell lines in this report and effectively alleviated bone cancer pain in our previous study, attenuated morphine tolerance in rats with chronic bone cancer pain at nonanalgesic doses. Furthermore, the intrathecal administration of l-CDL obviously attenuated morphine tolerance, and the effect was reversed by a D2DR agonist in mice. Spinal D2DR inhibition and l-CDL also inhibited tolerance induced by the MOR agonist DAMGO. l-CDL and a D2DR small interfering RNA (siRNA) decreased the increase in levels of phosphorylated Akt and MAPK in the spinal cord; these changes were abolished by a PI3K inhibitor. In addition, the activated Akt and MAPK proteins in mice exhibiting morphine tolerance were inhibited by a MOR antagonist. Intrathecal administration of a PI3K inhibitor also attenuated DAMGO-induced tolerance. Based on these results, l-CDL antagonized spinal D2DR to attenuate morphine tolerance by inhibiting PI3K/Akt-dependent MAPK phosphorylation through MOR. These findings provide insights into a more versatile treatment for morphine tolerance.

Design and Implementation of a Universal System Control Strategy Applicable to VSC-HVDC Systems

Zhao, Yue,Shi, Li-bao,Ni, Yi-xin,Xu, Zheng,Yao, Liang-zhong The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.1

This paper proposes a universal system control strategy for voltage source converter (VSC) based high voltage direct current (HVDC) systems. The framework of the designed control strategy consists of five layer structures considering the topology and control characteristics of the VSC-HVDC system. The control commands sent from the topmost layer can be transmitted to the next layer based on the existing communication system. When the commands are sent to each substation, the following transmission of commands between the four lower layers are realized using the internal communication system while ignoring the communication delay. This hierarchical control strategy can be easily applied to any VSC-HVDC system with any topology. Furthermore, an integrated controller for each converter is designed and implemented considering all of the possible operating states. The modular-designed integrated controller makes it quite easy to extend its operating states if necessary, and it is available for any kind of VSC. A detailed model of a VSC-HVDC system containing a DC hub is built in the PSCAD/EMTDC environment. Simulation results based on three operating conditions (the start-up process, the voltage margin control method and the master-slave control method) demonstrate the flexibility and validity of the proposed control strategy.

Design of 2-DOF decoupled large stroke precision positioning platform

Hua-wei Ji,Bo Lv,Tian-yi Li,Fan Yang,An-qi Qi,Xin Wu,Jing Ni 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.12

Aiming at the problem that the output displacement of the piezoelectric actuator is small and the coupling motion of the positioning platform affects the positioning accuracy, we designed a 2-DOF decoupling large-stroke precision positioning platform. First, a dynamic model based on the lumped mass method was established and verified by simulation. The multi-objective genetic optimization algorithm was used to optimize the structural size parameters of the positioning platform, and the optimal solution set of the structural size parameters of the positioning platform was obtained. Finally, according to the theoretical and simulation results, a prototype was fabricated and the working stroke, decoupling performance and natural frequency were tested experimentally. The results show the coupling rates between axes of the positioning platform in the x-direction and y-direction are 1.31 % and 1.62 %, respectively, the natural frequency is 337.2 Hz, and the positioning stroke is 89.2 μm×85.9 μm. The positioning platform designed in this paper is decoupled and has a large output stroke.

A Comparative Study of Camouflage Printing Color Matching Based on Monitor and Paper Card

Yu-wen Wang,Qing-zhu Yi,Yi Ding,Guang-xin Wu,Jing-bin Zhang,Ni Wang 한국섬유공학회 2021 Fibers and polymers Vol.22 No.4

To improve the accuracy of color reproduction for camouflage printing, a new color matching method, namedmonitor-paper-fabric, was proposed by importing color management into textiles, which matched the printing pastesaccording to the color of the paper card printed by the ink-jet printer after color management. Not like the traditional colormatching method, it matched the printing pastes according to the color from computer monitor after color correction. Twocolor matching methods were analyzed by comparing the color difference. It was found that the “monitor-paper-fabric” colormatching method could be considered as a convenient and feasible color matching method. Most color differences betweenthe monitor and the fabric in the camouflage pattern were reduced to lower than 4, except for color blocks 5 and 6. Inaddition, the color differences of six color blocks between the paper and the fabric were all less than 3.5, and were lower thanthose between the monitor and the fabric. The color consistency between the paper and the fabric was better than thatbetween the monitor and the fabric.

An Analytical Solution for Voltage Stability Studies Incorporating Wind Power

Lin, Yu-Zhang,Shi, Li-Bao,Yao, Liang-Zhong,Ni, Yi-Xin,Qin, Shi-Yao,Wang, Rui-Ming,Zhang, Jin-Ping The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Voltage stability is one of the most critical security issues which has not yet been well resolved to date. In this paper, an analytical method called PQ plane analysis with consideration of the reactive power capability of wind turbine generator and the wake effect of wind farm is proposed for voltage stability study. Two voltage stability indices based on the proposed PQ plane analysis method incorporating the uncertainties of load-increasing direction and wind generation are designed and implemented. Cases studies are conducted to investigate the impacts of wind power incorporation with different control modes. Simulation results demonstrate that the constant voltage control based on reactive power capability significantly enhances voltage stability in comparison of the conventional constant power factor control. Some meaningful conclusions are obtained.

An Analytical Solution for Voltage Stability Studies Incorporating Wind Power

Yu-Zhang Lin,Li-Bao Shi,Liang-Zhong Yao,Yi-Xin Ni,Shi-Yao Qin,Rui-Ming Wang,Jin-Ping Zhang 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Voltage stability is one of the most critical security issues which has not yet been well resolved to date. In this paper, an analytical method called PQ plane analysis with consideration of the reactive power capability of wind turbine generator and the wake effect of wind farm is proposed for voltage stability study. Two voltage stability indices based on the proposed PQ plane analysis method incorporating the uncertainties of load-increasing direction and wind generation are designed and implemented. Cases studies are conducted to investigate the impacts of wind power incorporation with different control modes. Simulation results demonstrate that the constant voltage control based on reactive power capability significantly enhances voltage stability in comparison of the conventional constant power factor control. Some meaningful conclusions are obtained.