Enhanced energy storage properties in PbZrO3 thin films via the incorporation of NiO

Wang X.W.,Chen J.Y.,Hu S.Y.,Yu K.X.,Yang F.,Shi Y.J.,Li J.H.,Hou M.Z.,Liu A.D.,Zheng M.M.,Yin S.Q.,Hu Y.C.,Shang J. 한국물리학회 2023 Current Applied Physics Vol.52 No.-

In this study, NiO–PbZrO3 composite films were deposited on SiO2/Si substrates buffered with LaNiO3 films via the sol-gel coating technique. The effects of NiO addition in PZO thin films on the microstructure, dielectric properties, leakage mechanism, ferroelectric properties and energy storage properties have been discussed. The dielectric constant increased with the addition of NiO, while the leakage current density decreased. Compared with pure PZO films, the maximum polarization of the composite films was improved. For the composite films prepared using the NiO precursor solution with 0.05 mol/L, the recoverable energy storage density of the NiO-PZO composite film is up to 19.6 J/cm3 under the electric field of 1038 kV/cm, which is 30% higher than that of the pure PZO film under the same conditions. Also, the energy storage efficiency of the composite film reaches 48%. Accordingly, we demonstrate a simple and convenient method by adding NiO to fabricate thin films with high energy storage performance.

Effects of trans-Resveratrol from Polygonum cuspidatum on Bone Loss Using the Ovariectomized Rat Model

Z.P. Liu,W.X. Li,B. Yu,J. Huang,J. Sun,J.S. Huo,C.X. Liu 한국식품영양과학회 2005 Journal of medicinal food Vol.8 No.1

trans-Resveratrol (resveratrol) has been shown in several studies to significantly modulate biomarkers of bone metabolism. But, there is no direct evidence supporting its inhibitory effect towards bone loss. In the present study, effects of resveratrol on bone mineral density (BMD) and bone calcium content (BCC) were examined in the ovariectomized (OVX) rat model. Female Wistar rats were divided into four groups: SHAM group (sham-operated), OVX group (OVX control), OVX ALD group (OVX and treated with 1.0 mg/kg of body weight of alendronate sodium), and OVX RES group (OVX and treated with 0.7 mg/kg of body weight of resveratrol). Tested materials were given by gavage for 12 weeks after ovariectomy. Results showed that rats in the OVX, OVX ALD, and OVX RES groups had significantly higher body weights and feed efficiency than those in the SHAM group (P .01). The OVX group had significantly lower femoral epiphysis BMD than the SHAM group, and epiphysis BMD in the OVX ALD and OVX RES groups was significantly greater than that in the OVX group (P .05). However, the femoral midpoint BMD was not significantly different among the four groups. Additionally, animals in the OVX group had significantly lower BCC compared with the SHAM group, while the BCC of the OVX ALD and OVX RES groups was significantly higher than that of the OVX group (P .05). These results indicated that resveratrol could increase epiphysis BMD and inhibit the decrease of femur BCC in OVX rats, suggesting that it could play a role in protecting against bone loss induced by estrogen deficiency.

An efficient method for tracing planar implicit curves

Yu, Z. s.,Cai, Y. z.,Oh, M. j.,Kim, T. w.,Peng, Q. s. Zhejiang University Press 2006 Journal of Zhejiang University Vol.7 No.7

Real-space observation of a two-dimensional skyrmion crystal

Yu, X. Z.,Onose, Y.,Kanazawa, N.,Park, J. H.,Han, J. H.,Matsui, Y.,Nagaosa, N.,Tokura, Y. Macmillan Publishers Limited. All rights reserved 2010 Nature Vol.465 No.7300

Crystal order is not restricted to the periodic atomic array, but can also be found in electronic systems such as the Wigner crystal or in the form of orbital order, stripe order and magnetic order. In the case of magnetic order, spins align parallel to each other in ferromagnets and antiparallel in antiferromagnets. In other, less conventional, cases, spins can sometimes form highly nontrivial structures called spin textures. Among them is the unusual, topologically stable skyrmion spin texture, in which the spins point in all the directions wrapping a sphere. The skyrmion configuration in a magnetic solid is anticipated to produce unconventional spin??electronic phenomena such as the topological Hall effect. The crystallization of skyrmions as driven by thermal fluctuations has recently been confirmed in a narrow region of the temperature/magnetic field (T??B) phase diagram in neutron scattering studies of the three-dimensional helical magnets MnSi (ref. 17) and Fe<SUB>1−x</SUB>Co<SUB>x</SUB>Si (ref. 22). Here we report real-space imaging of a two-dimensional skyrmion lattice in a thin film of Fe<SUB>0.5</SUB>Co<SUB>0.5</SUB>Si using Lorentz transmission electron microscopy. With a magnetic field of 50??70 mT applied normal to the film, we observe skyrmions in the form of a hexagonal arrangement of swirling spin textures, with a lattice spacing of 90 nm. The related T??B phase diagram is found to be in good agreement with Monte Carlo simulations. In this two-dimensional case, the skyrmion crystal seems very stable and appears over a wide range of the phase diagram, including near zero temperature. Such a controlled nanometre-scale spin topology in a thin film may be useful in observing unconventional magneto-transport effects.

Fabrication of Nano-Sized Indium Oxide Powder below 50nm by Spray Pyrolysis Process

Yu, J. K.,Kang, S. G.,Han, J. S.,Ahn, Z. S. Scitec Publications Ltd. 2007 Solid State Phenomena Vol.124-126 No.2

GA-BASED PID AND FUZZY LOGIC CONTROL FOR ACTIVE VEHICLE SUSPENSION SYSTEM

J. Z. FENG,J. LI,F. YU 한국자동차공학회 2003 International journal of automotive technology Vol.4 No.4

Since the nonlinearity and uncertainties which inherently exist in vehicle system need to be considered in active suspension control law design, this paper proposes a new control strategy for active vehicle suspension systems by using a combined control scheme, i.e., respectively using a genetic algorithm (GA) based self-tuning PID controller and a fuzzy logic controller in two loops. In the control scheme, the PID controller is used to minimize vehicle body vertical acceleration, the fuzzy logic controller is to minimize pitch acceleration and meanwhile to attenuate vehicle body vertical acceleration further by tuning weighting factors. In order to improve the adaptability to the changes of plant parameters, based on the defined objectives, a genetic algorithm is introduced to tune the parameters of PID controller, the scaling factors, the gain values and the membership functions of fuzzy logic controller on-line. Taking a four degree-or-freedom nonlinear vehicle model as example, the proposed control scheme is applied and the simulations are carried out in different road disturbance input conditions. Simulation results show that the present control scheme is very effective in reducing peak values of vehicle body accelerations, especially within the most sensitive frequency range of human response, and in attenuating the excessive dynamic tire load to enhance road holding performance. The stability and adaptability are also showed even when the system is subject to severe road conditions, such as a pothole, an obstacle or a step input. Compared with conventional passive suspensions and the active vehicle suspension systems by using, e.g., linear fuzzy logic control, the combined PID and fuzzy control without parameters self-tuning, the new proposed control system with GA-based self-learning ability can improve vehicle ride comfort performance significantly and offer better system robustness.<br/>

A durability study of carbon nanotube fiber based stretchable electronic devices under cyclic deformation

Yu, J.,Wang, L.,Lai, X.,Pei, S.,Zhuang, Z.,Meng, L.,Huang, Y.,Li, Q.,Lu, W.,Byun, J.H.,Oh, Y.,Yan, Y.,Chou, T.W. Pergamon Press ; Elsevier Science Ltd 2015 Carbon Vol.94 No.-

In spite of the recent rapid growth in stretchable electronic device research, efforts have been mainly focused on material selection, device geometric design and short-term performance characterization. The present research focuses on the long-term durability of electromechanical and electrochemical performance of buckled carbon nanotube fibers based stretchable conductors and supercapacitors under cyclic deformation. The damage mode and damage evolution as a function of fatigue deformation are identified. After 10,000 stretching-releasing cycles with mechanical deformation up to 40% strain, the conductivities of buckled dry spun and aerogel spun CNT fiber based stretchable conductors exhibit excellent stability and the resistances increase by only about 0.2% and 6%, respectively. The areal specific capacitances of buckled dry spun and aerogel spun CNT fiber based stretchable supercapacitors change, respectively, from 4.42mFcm<SUP>-2</SUP> to 3.60mFcm<SUP>-2</SUP>, and from 8.16mFcm<SUP>-2</SUP> to 9.95mFcm<SUP>-2</SUP> at the scan rate of 50mVs<SUP>-1</SUP> after 10,000 deformation cycles.

IMC and creep behavior in Lead-free solder joints of Sn-Ag and Sn-Ag-Cu alloy system by SP method

Yang, Z. J.,Yang, S. M.,Yu, H. S.,Kang, S. J.,Song, J. H.,Kim, K. J. Springer Science + Business Media 2014 International journal of automotive technology Vol.15 No.7

GA-BASED PID AND FUZZY LOGIC CONTROL FOR ACTIVE VEHICLE SUSPENSION SYSTEM

Feng, J.-Z.,Li, J.,Yu, F. The Korean Society of Automotive Engineers 2003 International journal of automotive technology Vol.4 No.4

Since the nonlinearity and uncertainties which inherently exist in vehicle system need to be considered in active suspension control law design, this paper proposes a new control strategy for active vehicle suspension systems by using a combined control scheme, i.e., respectively using a genetic algorithm (GA) based self-tuning PID controller and a fuzzy logic controller in two loops. In the control scheme, the PID controller is used to minimize vehicle body vertical acceleration, the fuzzy logic controller is to minimize pitch acceleration and meanwhile to attenuate vehicle body vertical acceleration further by tuning weighting factors. In order to improve the adaptability to the changes of plant parameters, based on the defined objectives, a genetic algorithm is introduced to tune the parameters of PID controller, the scaling factors, the gain values and the membership functions of fuzzy logic controller on-line. Taking a four degree-of-freedom nonlinear vehicle model as example, the proposed control scheme is applied and the simulations are carried out in different road disturbance input conditions. Simulation results show that the present control scheme is very effective in reducing peak values of vehicle body accelerations, especially within the most sensitive frequency range of human response, and in attenuating the excessive dynamic tire load to enhance road holding performance. The stability and adaptability are also showed even when the system is subject to severe road conditions, such as a pothole, an obstacle or a step input. Compared with conventional passive suspensions and the active vehicle suspension systems by using, e.g., linear fuzzy logic control, the combined PID and fuzzy control without parameters self-tuning, the new proposed control system with GA-based self-learning ability can improve vehicle ride comfort performance significantly and offer better system robustness.

p38 kinase mediates nitric oxide-induced apoptosis of chondrocytes through the inhibition of protein kinase C ζ by blocking autophosphorylation

Kim, J-S,Park, Z-Y,Yoo, Y-J,Yu, S-S,Chun, J-S Nature Publishing Group 2005 CELL DEATH AND DIFFERENTIATION Vol.12 No.3

This study investigated the molecular mechanisms underlying inhibition of protein kinase C (PKC) ζ by p38 kinase during nitric oxide (NO)-induced apoptosis of chondrocytes. Coimmunoprecipitation experiments showed that activation of p38 kinase following addition of an NO donor resulted in a physical association between PKCζ and p38 kinase. Direct interaction of p38 kinase with PKCζ was confirmed in vitro using p38 kinase and PKCζ recombinant proteins. p38 kinase interacts with the regulatory domain of PKCζ and its association blocked PKCζ autophosphorylation. Micro LC–MS/MS analysis using recombinant proteins indicated that the interaction of p38 kinase with PKCζ blocked autophosphorylation of PKCζ on Thr-560, which is required for PKCζ activation. Collectively, our results demonstrate a novel mechanism of PKCζ regulation: following activation by the production of NO, p38 kinase binds directly to the PKCζ regulatory domain, preventing PKCζ autophosphorylation on Thr-560, thereby inhibiting PKCζ activation.Cell Death and Differentiation (2005) 12, 201–212. doi:10.1038/sj.cdd.4401511 Published online 21 January 2005