Orders-of-magnitude enhancement in conductivity tuning in InGaZnO thin-film transistors via SiNx passivation and dual-gate modulation

ChangDong Chen,ChenNing Liu,JiWen Zheng,GongTan Li,Shan Li,QianWu,JinWu,Chuan Liu 한국정보디스플레이학회 2019 Journal of information display Vol.20 No.3

The mobility of pristine amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) is insufficient to meet the requirement of the future ultra-high-definition displays. Reported herein is the fabrication of hydrogenated long-channel IGZO TFTs exhibiting a transconductance and an on/off ratio that are orders of magnitude superior to those of the regular devices. The gate bias stability of the treated IGZO TFTs was greatly enhanced, with the threshold voltage shifting by less than 1 V after 1 h stress. Experimentally, the hydrogenation of the active layer was achieved via the deposition of a SiNx/SiOx bilayer on top of the IGZO via plasma-enhanced chemical vapor deposition followed by post-annealing under optimized conditions. The elemental depth profiles indicated that this enhanced performance originated from the hydrogen doping of the IGZO film. Furthermore, a dual-gate structure was fabricated to alleviate the deterioration of the subthreshold properties induced by the excess hydrogen doping.

Optimal Location of Piles in Stabilizing Slopes Based on a Simplified Double-row Piles Model

Changdong Li,Wenqiang Chen,Yingjie Song,Wenping Gong,Qihua Zhao 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.2

Embedding single-row piles is often adopted to stabilize slopes in engineering practice. However, for large-scale and complex slopes, single-row piles might not be able to stabilize the slope; rather, double-row piles, even multirow piles, should be adopted. Currently, the optimal locations of double-row stabilizing piles considering local instability of the slope have rarely been studied. In this paper, a simplified analytical model used to analyze double-row pile stabilized slopes is proposed, where the local failure of the slope above the first row of piles is considered. Through the kinematic approach of limit analysis combined with the strength reduction technique, the required resistance forces provided by double-row piles respectively are derived for different pile locations denoted by the rotational angle. Moreover, a framework is developed for analyzing the optimal locations of multirow piles considering multistage potential slip surfaces. The results of an illustrative example are presented, and the reasonableness of the proposed method is verified. It is concluded that the optimal locations of double-row piles lie within middle-lower part of the corresponding stabilized part of the slope. Finally, discussion illustrates the influences of the seismic effects and soil shear strength parameters on the derived optimal pile locations. This study provides novel scientific insight into the optimized design of stabilizing pile locations in engineering practice.

Application of Self-organizing Mapping-Random Forest Model to Map Landslide Susceptibility in Zigui Basin, Three Gorges Reservoir Region, China

( Changdong Li ),( Jingjing Long ),( Zhiyong Fu ),( Wenqiang Chen ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

The Zigui basin is one of the most landslide-prone areas where thousands of landslides are distributed. Researches show that areas sharing the same conditions as identified landslides are clearly potential areas for future disasters. Performing the landslide susceptibility mapping is a heated issue in the area. Continued improvements in high-resolution satellite images, and the developments of unmanned aerial vehicles (UAVs) and site-investigation function well in constructing effective, high-quality landslide databases. GIS technology and machine learning algorithms have been widely applied in landslide susceptibility prediction. Whereas, whether the random and subjective selection of the landslides or non-landslides grid cells are reasonable in research of landslide susceptibility mapping is the existence problem. Based on the Two step cluster (TSC) algorithm and the Self-organizing mapping - Random forest (SOM-RF) model, a novel hybrid model is proposed to overcome the above drawbacks. SOM is used to produce a preliminary landslide susceptibility mapping. TSC algorithm is applied in telling apart the most reasonable True-Positive (TP) from recorded landslide grid cells in high-susceptibility zones and the False-Positive (FP) in low-susceptibility zones. Afterwards, the labeled datasets are imported into the RF model for training. And then the trained SOM-RF model is utilized to perform an improved landslide susceptibility mapping. Most areas with high or very high susceptibility are located within the hydro-fluctuation belt of the TGR. Compared with the susceptibility mapping produced by single RF model, the results of SOM-RF model demonstrate to have the superior prediction skill and higher reliability.

Experimental and Modeling Analysis of Hydrogen Motion Behavior in Welding Zone of 2.25Cr–1Mo–0.25 V Steel Welded Joint with Hydrogen Corrosion

Changdong Yin,Dongdong Ye,Zhou Xu,Jianjun Chen,Yiwen Wu,Houli Liu,Xin Ge,Qiang Liu,Guiling Zeng 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.8

Understanding and solving the problem of hydrogen damage due to the degradation of service performance of high-strengthsteel caused by hydrogen penetration is a milestone for the reliability improvement of high-end hydrogen energy equipment. From the perspective of microscopic hydrogen movement behavior, this study investigated the permeability of hydrogenin base metal (BM) and welded metal (WM) of 2.25Cr–1Mo–0.25 V steel welded joint through electrochemical hydrogenpermeation test, and the analytical models of hydrogen penetration and hydrogen diffusion in the welding zone were established,and the effect of adding hydrogen-resistant coatings (HRCs) on hydrogen movement behavior in steel substrate wasstudied. The results showed that the diffusivity of hydrogen in WM of the welded joint was significantly lower than thatin BM, and the hydrogen concentration in BM was higher than that in WM at the beginning of hydrogenation without theaddition of HRCs protection, while it tended to be consistent at the later stage. However, the hydrogen concentration in WMwas lower than that in BM after adding HRCs and would be always higher than that in BM after a certain period of time,and the difference was directly related to the hydrogen resistance of the coatings. Additionally, the difference between theintermediate and outer layers for the welding zone steel substrate with and without HRCs presented a trend of rapid increasefollowed by a slow decrease. These findings could provide an important reference value for hydrogen damage protectionmeasures and related researches on HRCs.

Component Prototyping for the China Spallation Neutron Source Project

Jie Wei,Yanwei Chen,Yunlong Chi,Changdong Deng,Haiyi Dong,Shinian Fu,Wei He,Kaixi Huang,Wen Kang,Jian Li,Huafu Ouyang,Huamin Qu,Caitu Shi,Hong Sun,Jingyu Tang,Juzhou Tao,Sheng Wang,Zhongxiong Xu,Xueju 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.54 No.5

The China Spallation Neutron Source (CSNS) complex consists of an H- linear accelerator, a rapid cycling synchrotron accelerating the beam to 1.6 GeV, a solid tungsten target station and instruments for spallation neutron applications. The facility operates at a 25-Hz repetition rate with an initial design beam power of 120 kW and is upgradeable to 500 kW. The primary challenge is to build a robust and reliable user-friendly facility with upgrade potential at a fraction of the \world standard" cost. Success of the project relies on the results of prototyping research & development (R&D) of key technical systems and components. This paper discusses the prototyping experiences of the past two and a half years. The China Spallation Neutron Source (CSNS) complex consists of an H- linear accelerator, a rapid cycling synchrotron accelerating the beam to 1.6 GeV, a solid tungsten target station and instruments for spallation neutron applications. The facility operates at a 25-Hz repetition rate with an initial design beam power of 120 kW and is upgradeable to 500 kW. The primary challenge is to build a robust and reliable user-friendly facility with upgrade potential at a fraction of the \world standard" cost. Success of the project relies on the results of prototyping research & development (R&D) of key technical systems and components. This paper discusses the prototyping experiences of the past two and a half years.