Recent Developments in the Effects of Different Dopants on the Structure and Property of Lithium Titanate Material

Xi-Yang Li,Qian-Lin Chen,Min Yang,Ya-Nan Li,Jing-Bo Ma 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.3

The lithium titanium spinel Li4Ti5O12 has attracted more and more attention as anode materials applied in lithium ion batteries. Li4Ti5O12 material has been found to be able to intercalate lithium ions without deformation of the lattice. However, compared with graphite and other anode materials, the low conductivity of Li4Ti5O12 restricts its charging and discharging rate. Doping is deemed to be a businesslike method to enhance ionic and electronic conductivity of Li4Ti5O12. This paper reviews the effects of Li4Ti5O12 with different doping ions on different crystal lattice states. And it has been found by a summary that the doping objective of doping ions at Li4Ti5O12 is also different. Moreover, the applications of ion doping in different fields of Li4Ti5O12 are prospected.

Effect of the Molar Ratio of Li/Ti and Thermal Treatment on the Electrochemical Performance of Li4Ti5O12–rutile TiO2 Nanocomposite as Anode Materials

Zhen Yang,Xi-Ping Li,Jian Mao 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.8

Li4Ti5O12–rutile TiO2 (LTO–RTO) dual-phase nanocomposite anode materials show excellent electrochemical performance. However, the effects of molar ratio of Li/Ti and thermal treatment on electrochemical properties of the LTO–RTO composite have been rarely reported. In this work, LTO–RTO nanocomposites were prepared by sol-hydrothermal method with different Li/ Ti molar ratios in raw materials and following calcinations at 600℃, 650℃ and 700℃ for the different holding time. The results indicate that with the decrease of Li/Ti molar ratio, the discharge capacity of the LTO–RTO nanocomposite increases at first and then decreases, and the optimal Li/Ti molar ratio is 4:4.77, which was obtained with calcination at 600℃ for 10 h. The effects of calcination temperature and holding time were further investigated. The result demonstrates that the thermal treatment has an obvious influence on the electrochemical performance due to the morphology change in the nanocomposite. The LTO–RTO nanocomposite calcinated at 650℃ for 2 h with a Li/Ti molar ratio of 4:4.77 in raw materials delivers excellent rate capability: the initial discharge capacity is 175.9, 176.3, 170.4, 167.5, 163.3 and 155.6 mA h g-1 at the rate of 0.5, 1, 3, 5, 10 and 20℃ (1 C = 175 mA h g-1), respectively.

Particle size distributions and concentrations above radiators in indoor environments: Exploratory results from Xi`an, China

Xi Chen,Angui Li 대한환경공학회 2015 Environmental Engineering Research Vol.20 No.3

Particulate matter in indoor environments has caused public concerns in recent years. The objective of this research is to explore the influence of radiators on particle size distributions and concentrations. The particle size distributions as well as concentrations above radiators and in the adjacent indoor air are monitored in forty-two indoor environments in Xi’an, China. The temperatures, relative humidity and air velocities are also measured. The particle size distributions above radiators at ten locations are analyzed. The results show that the functional difference of indoor environments has little impact on the particle size distributions above radiators. Then the effects of the environmental parameters (particle concentrations in the adjacent indoor air, temperatures, relative humidities and air velocities) on particle concentrations above radiators are assessed by applying multiple linear regression analysis. Three multiple linear regression models are established to predict the concentrations of PM10, PM2.5 and PM1 above radiators.

Test Study on the Air Permeability of Remolded Q3 Malan Loess

Jia Liu,Xi’an Li,Zeze Guo,Quan Xue,Li Wang,Jinyang Liu 대한토목학회 2021 KSCE Journal of Civil Engineering Vol.25 No.8

Gas permeability is an important parameter in the determination of the pore structure characteristics of loess, especially in engineering fields such as earthwork and landfill cover treatment. With an improved ZC-2015 air permeameter, the air permeability (ka) testing under different water contents (w), dry densities (ρd) and wetting paths was conducted on remolded Q3 Malan loess from the Chanhe River area in Xi’an, Shaanxi, China. The results indicate that the ka of the remolded loess decreased rapidly as ρd increased and exhibited a relatively complex pattern as w increased. When w was less than the plastic limit (wp) and ρdwas relatively low (1.35 g·cm−3, 1.45 g·cm−3), ka decreased as we increased. When ρd reached a certain value (1.50 g·cm−3, 1.65 g·cm−3), the ka–we curve exhibited a notable turning point. When ρd continued to increase 1.70 g·cm−3, ka decreased as we increased. The results of microscopic analysis, suggested that under the action of different water content and compaction, levels of aggregates and pore structures were formed. A Poulsen model was used to predict the ka and the test results were in relatively coincident with the calculation results, demonstrating that the Poulsen model is applicable.

AUTOMA TIC ACQUISITION OF TRANSLATION EQUIVALENCES FROM BILINGUAL CORPUS

Chun-xiαng Zhang,Tie-jun Zhao,Sheng Li 한국어정보학회 2005 국제학술대회 Vol.2005 No.08

Analytical calculation method for the axial equivalent elastic modulus of laminated FRP pipes based on three-dimensional stress state

Li Chen,Darong Pan,Qilin Zhao,Li-Cheng-Xi Huang,Liang Chen,Wei Xu 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.77 No.1

In engineering design, the axial equivalent elastic modulus of laminated FRP pipe was mostly calculated by the average elastic modulus method or the classical laminated plate theory method, which are based on relatively simplified assumptions, and may be not accurate enough sometimes. A new analytical calculation method for the axial equivalent elastic modulus of laminated FRP pipe was established based on three-dimensional stress state. By comparing the results calculated by this method with those by the above two traditional analytical methods and the finite element method, it is found that this method for the axial equivalent elastic modulus fits well not only for thin-walled pipes with orthotropic layers, but also for thick-walled pipes with arbitrary layers. Besides, the influence of the layer stacking on the axial equivalent elastic modulus was studied with this method. It is found that a proper content of circumferential layer is beneficial for improving the axial equivalent elastic modulus of the laminated FRP pipe with oblique layers, and then can reduce its material quantity under the premise that its axial stiffness remains unchanged. Finally, the meso-mechanical mechanism of this effect was analyzed. The improving effect of circumferential layer on the axial equivalent elastic modulus of the laminated FRP pipe with oblique layers is mainly because that, the circumferential fibers can restrain the rigid body rotations of the oblique fibers, which tend to cause the significant deformations of the pipe wall units and the relatively low axial equivalent elastic modulus of the pipe.

Magnolol-Induced H460 Cells Death via Autophagy but Not Apoptosis

Li, Hai-Bo,Yi, Xin,Gao, Jian-Mei,Ying, Xi-Xiang,Guan, Hong-Quan,Li, Jian-Chun 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.12

We have reported that the protective effect of Magnolol on TBHP-induced injury in human non-small lung cancer H460 cells is partially via a p53 dependent mechanism. In this study, we found that Magnolol displayed a stimulatory effect at low concentrations $(\leq20{\mu}M)$ whilst inhibitory effect at high concentrations $(\geq20{\mu}M)$ in H460 cells. To investigate the mechanism of inducing the biphasic effect in H460 cells with Magnolol, we showed that Magnolol stimulated DNA synthesis at low concentrations and displayed an inhibition effect at high concentrations in H460 cells. More importantly, the inhibition of DNA synthesis was accompanied by the S phase cell cycle arrest and the appearance of intense intracytoplasmic vacuoles. These vacuoles can be labeled by autophagic marker monodansylcadaverin (MDC), 3-methyladenine (3-MA), an inhibitor of autophagy, was able to inhibit the occurrence of autophagy. The results of the LDH activity assay and TUNEL assay also showed that Magnolol at high concentrations inhibiting H460 cell growth was not via apoptotic pathway. Furthermore, accompanied by the occurrence of autophagy, the expression of phospho-Akt was down-regulated but PTEN significantly was up-regulated. In conclusion, Magnolol induces H460 cells death by autophagy but not apoptotic pathway. Blockade of PI3K/PTEN/Akt pathway is maybe related to Magnolol-induced autophagy. Autophagic cells death induction by Magnolol underlines the potential utility of its induction as a new cancer treatment modality.

A Highly Stereoselective Synthesis and Crystal Structure of (E)-4'-Amino-3,4,5- trimethoxystilbene

Li, Xia-Bing,Zhang, Xi-Quan,Gu, Hong-Mei,Li, Bao-Lin Korean Chemical Society 2011 대한화학회지 Vol.55 No.2

3,4,5-Trimethoxybenzaldehyde과 p-nitrotoluene을 출발물질로 하여 두 단계 반응으로 (E)-4'-amino-3,4,5-trimethoxystilbene을 합성할 수 있는 합성 방법을 개발하였으며, 이 화합물에 대한 결정 구조를 X-ray 회절분석법으로 결정하였다. A new and highly stereoselective synthesis of (E)-4'-amino-3,4,5-trimethoxystilbene was achieved by using 3,4,5-trimethoxybenzaldehyde and p-nitrotoluene as starting materials through condensation under solvent-free condition and followed by the reducing of nitro group with the system of $NH_2NH_2/FeCl_3$/C in ethanol. The crystal structure of (E)-4'-amino-3,4,5-trimethoxystilbene was also determined by X-ray diffraction analysis.

Adaptive Multiple MPC for a Wind Farm with DFIG: a Decentralized-Coordinated Approach

LI, Xiao-ming,ZHANG, Xi,LIN, Zhong-wei,NIU, Yu-guang,LI, Ming-yang,Nathan, Noel Vishal The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.5

Network Security Situation Assessment Method Based on Markov Game Model

( Xi Li ),( Yu Lu ),( Sen Liu ),( Wei Nie ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.5

In order to solve the problem that the current network security situation assessment methods just focus on the attack behaviors, this paper proposes a kind of network security situation assessment method based on Markov Decision Process and Game theory. The method takes the Markov Game model as the core, and uses the 4 levels data fusion to realize the evaluation of the network security situation. In this process, the Nash equilibrium point of the game is used to determine the impact on the network security. Experiments show that the results of this method are basically consistent with the expert evaluation data. As the method takes full account of the interaction between the attackers and defenders, it is closer to reality, and can accurately assess network security situation.