A potential red-emitting phosphor with high color-purity for near-UV light emitting diodes

Zhengliang Wang,Yaling Zhang,Li Xiong,Xiaofan Li,Junming Guo,Menglian Gong 한국물리학회 2012 Current Applied Physics Vol.12 No.4

New red tungstates phosphors, Na5La1-xLnx(WO4)4 (Ln = Eu, Sm) and Na5Eu1-xSmx(WO4)4, were prepared by solid-state reaction technique. And their structure and photo-luminescent properties were investigated. The introduction of Sm3+ broadened the excitation band around 400 nm of the phosphors,and strengthened the red emission. And the possible energy transfer process from Sm3þ to Eu3+ is discussed. The single red LED was fabricated by combining InGaN chip with Na5Eu0.94Sm0.06(WO4)4 as red phosphor, intense red light can be observed by naked eyes. Then the phosphor Na5Eu0.94Sm0.06(WO4)4 may be a good candidate for red component of near-UV InGaN-based W-LEDs,because of efficient red-emitting with broadened absorption around 400 nm and appropriate CIE chromaticity coordinates (x = 0.65, y = 0.34).

Notch ligand Jagged1 promotes mesenchymal stromal cell-based cartilage repair

Junkui Sun,Zhengliang Luo,Guangxi Wang,Yuping Wang,Yisheng Wang,Margaret Olmedo,Massimo Max Morandi,Shane Barton,Christopher G. Kevil,Bing Shu,Xifu Shang,Yufeng Dong 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

Placenta-derived mesenchymal stromal cells (PMSCs) provide a promising cell source for tissue regeneration. However, rapid induction of PMSC chondrogenic differentiation during therapeutic transplantation remains extremely challenging. Here we undertook a study to determine if Notch inhibition by soluble Jagged1 (JAG1) peptides could be utilized to accelerate PMSC-induced cartilage regeneration in a mouse post-traumatic osteoarthritis (PTOA) model. Our results showed that treatment of PMSCs with soluble JAG1 significantly enhanced chondrogenesis in culture as shown by increased alcian blue staining and decreased Notch target Hes1 expression when compared to those in lgG-treated control cells. Importantly, significantly enhanced cartilage formation and decreased joint inflammation were observed when JAG1-treated PMSCs were injected into mouse PTOA knee joints. Finally, in vivo cell tracing showed that more JAG1-treated PMSCs remained in knee joint tissues and that JAG1-treated PMSCs exhibited greater PMSC chondrogenic differentiation than lgG-treated control PMSCs at 4 weeks after injection. These data indicate that transient Notch inhibition by soluble JAG1 could be used to enhance PMSC survival and chondrogenic differentiation, thereby increasing the therapeutic potential of PMSCs for cartilage regeneration.

High Strength Vinegar Fermentation by Acetobacter pasteurianus via Enhancing Alcohol Respiratory Chain

Zhengliang Qi,Hailin Yang,Xiaole Xia,Wu Wang,Xiao-Bin Yu 한국생물공학회 2014 Biotechnology and Bioprocess Engineering Vol.19 No.2

Seeking high strength vinegar fermentation byacetic acid bacteria (AAB) is still the mission of vinegarproducers. AAB alcohol respiratory chain, located onintracellular membrane, is directly responsible for vinegarfermentation. In the semi-continuous vinegar fermentationby Acetobacter pasteurianus CICIM B7003, acetificationrate showed positive correlation with the activity of theenzymes in alcohol respiratory chain. Aiming at achievinghigh strength fermentation process, a series of trials weredesigned to raise the activity of AAB alcohol respiratorychain. Finally, acetification was enhanced by adding someprecursors (ferrous ions and β-hydroxybenzoic acid) ofalcohol respiration associated factors and increasing aerationrate (0.14 vvm). As final result, average acetification ratehas been raised to 2.29 ± 0.02 g/L/h, which was 28.7%higher than the original level. Simultaneously, it was foundthat the oxidization of alcohol into acetic acid in AAB cellswas improved by well balancing of three factors: enzymeactivity in alcohol respiratory chain, precursor of ubiquinonebiosynthesis, and aeration rate.

Vortex induced vibration and its controlling of long span Cross-Rope Suspension transmission line with tension insulator

Xi Tu,Ye Wu,Zhengliang Li,Zhisong Wang 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.78 No.1

Long span cross-rope suspension structure is an innovative structural system evolved from typical Cross-Rope Suspension (CRS) guyed tower, a type of supporting system with short span suspension cable supporting overhead power transmission lines. In mountainous areas, the span length of suspension cable was designed to be extended to hundreds or over one thousand meters, which is applicable for crossing deep valleys. Vortex Induced Vibration (VIV) of overhead power transmission lines was considered to be one of the major factors of its fatigue and service life. In this paper, VIV and its controlling by Stockbridge damper for long span CRS was discussed. Firstly, energy balance method and finite element method for assessing VIV of CRS were presented. An approach of establishing FE model of long span CRS structure with dampers was introduced. The effect of Stockbridge damper for overall vibration of CRS was compared in both theoretical and numerical approaches. Results indicated that vibration characteristics of conductor in long span CRS compared with traditional tower-line system. Secondly, analysis on long span CRS including Stockbridge damper showed additional dampers installed were essential for controlling maximum dynamic bending stresses of conductors at both ends. Moreover, factors, including configuration and mass of Stockbridge damper, span length of suspension cable and conductor and number of spans of conductor, were assessed for further discussion on VIV controlling of long span CRS.

Prediction of downburst-induced wind pressure coefficients on high-rise building surfaces using BP neural network

Zhiyuan Fang,Zhisong Wang,Zhengliang Li 한국풍공학회 2020 Wind and Structures, An International Journal (WAS Vol.30 No.3

Gusts generated by downburst have caused a great variety of structural damages in many regions around the world. It is of great significance to accurately evaluate the downburst-induced wind load on high-rise building for the wind resistance design. The main objective of this paper is to propose a computational modeling approach which can satisfactorily predict the mean and fluctuating wind pressure coefficients induced by downburst on high-rise building surfaces. In this study, using an impinging jet to simulate downburst-like wind, and simultaneous pressure measurements are obtained on a high-rise building model at different radial locations. The model test data are used as the database for developing back propagation neural network (BPNN) models. Comparisons between the BPNN prediction results and those from impinging jet test demonstrate that the BPNN-based method can satisfactorily and efficiently predict the downburst-induced wind pressure coefficients on single and overall surfaces of high-rise building at various radial locations.

KGd(MoO4)2:Eu3+ as a promising red phosphor for light-emitting diode application

Linghong Yi,Liya Zhou,Zhengliang Wang,Jianhua Sun,Fuzhong Gong,Weiping Wan,Wei Wang 한국물리학회 2010 Current Applied Physics Vol.10 No.1

A red phosphor KGd(MoO4)2:Eu3+ was prepared by solid-state reaction technique at high temperature. Its photoluminescent property was investigated and the optimum concentration of Eu3+ doped in the KGd(MoO4)2 is 25 mol%. Compared with Y2O2S:0.05Eu3+, the obtained KGd(MoO4)2:Eu3+ shows wider excitation band around 400 nm, higher intensity of Eu3+ 5D0.7F2 emission upon excitation 393 nm, and the CIE chromaticity coordinates (x = 0.655, y = 0.345) are closer to the standard of National Television Standard Committee (NTSC). The optical properties of KGd(MoO4)2:Eu3+ suggest that it is an efficient red-emitting phosphor for light-emitting diode applications.

Probabilistic bearing capacity assessment for cross-bracings with semi-rigid connections in transmission towers

Zhengqi Tang,Tao Wang,Zhengliang Li 국제구조공학회 2024 Structural Engineering and Mechanics, An Int'l Jou Vol.89 No.3

In this paper, the effect of semi-rigid connections on the stability bearing capacity of cross-bracings in steel tubular transmission towers is investigated. Herein, a prediction method based on the hybrid model which is a combination of particle swarm optimization (PSO) and backpropagation neural network (BPNN) is proposed to accurately predict the stability bearing capacity of cross-bracings with semi-rigid connections and to efficiently conduct its probabilistic assessment. Firstly, the establishment of the finite element (FE) model of cross-bracings with semi-rigid connections is developed on the basis of the development of the mechanical model. Then, a dataset of 7425 samples generated by the FE model is used to train and test the PSO-BPNN model, and the accuracy of the proposed method is evaluated. Finally, the probabilistic assessment for the stability bearing capacity of cross-bracings with semi-rigid connections is conducted based on the proposed method and the Monte Carlo simulation, in which the geometric and material properties including the outer diameter and thickness of cross-sections and the yield strength of steel are considered as random variables. The results indicate that the proposed method based on the PSOBPNN model has high accuracy in predicting the stability bearing capacity of cross-bracings with semi-rigid connections. Meanwhile, the semi-rigid connections could enhance the stability bearing capacity of cross-bracings and the reliability of crossbracings would significantly increase after considering semi-rigid connections.