A self-powered β-Ga2O3/CsCu2I3 heterojunction photodiode responding to deep ultraviolet irradiation

Gao Ang,Jiang Weiyu,Ma Guoliang,Liu Zeng,Li Shan,Yan Zuyong,Sun Weiming,Zhang Shaohui,Tang Weihua 한국물리학회 2022 Current Applied Physics Vol.33 No.-

In this paper, a lead-free halide perovskite CsCu2I3 film with high stability was prepared by the anti-solvent assisted crystallization method. Then, we coupled it with Ga2O3 to prepare a corresponding heterojunction deep ultraviolet (UV) photodetector. After testing, we concluded that the photodetector is sensitive to 254 nm UV light. The photodetector has good reproducibility, and has an ultra-high photo-to-dark current ratio (PDCR) of more than 105. In addition, under a bias of 10 V and an illuminated intensity of 200 μW/cm2, the responsivity (R) and specific detectivity (D*) reached 20 mA/W and 107 cm Hz1/2 W 1 (Jones), and the external quantum efficiency (EQE) is 10%. Meanwhile, the prepared photodetector could operate at zero bias, i.e., self-powered operation, along with a photocurrent of about 1 nA under illumination with UV light intensity of 200 μW/cm2.

Heuristic Algorithm Based on MAXDCP and GEOCP in Grid Networ

Shaohui Ma,Xiangqian Chen 보안공학연구지원센터 2015 International Journal of Grid and Distributed Comp Vol.8 No.3

In order to solve issues of grid network as a broadband wireless access network, such as high data transmission rate and long-distance signal coverage and so on, this paper proposes two heuristic algorithms with O (m3) time complexity, based on the user neighbors’ information and location information. The algorithm will meet transferring the minimum relay deployment problem required by users into the minimum clique partition problem of adjacency graph and gives specific algorithm steps. Experimental results show that: the proposed algorithm ensures network performance and reduces network cost.

The Acoustic Emission Signal Recognition based on Wavelet Transform and RBF Neural Network

Shaohui Ma,Xiangqian Chen 보안공학연구지원센터 2015 International Journal of Grid and Distributed Comp Vol.8 No.2

The acoustic emission (AE) technology can be used to assess the security condition of oil storage tank without opening pot. Signal recognition is a foundation to analyze the corrosion status for oil storage tanks. Because of inadequateness of the analysis method of parameters, a new acoustic emission signal recognition method is proposed based on wavelet transform and RBF neural network. AE signal was decomposed to 6 layers by db2 wavelet and the space energy of 6-layer detail features is regarded as the vector of the AE signal characteristics. RBF neural network is designed by considering the characteristics of AE signal. The RBF neural network is trained by using the pattern known of acoustic emission signal. RBF network is used to classify experiments to corrosion, crack and condensation acoustic emission signal. The experimental results show that the recognition rate of RBF neural network reaches 93.3%, which reveals the advantage of the acoustic emission signal of neural network recognition. It has some significance of the quantitative analysis to the safety situation of oil storage tanks.

Optimization Algorithm Based on Laplacian Location and Extension Grid

Shaohui Ma,Xinling Sun,Benzhai Hai,Xie Rui-yun 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.9

This article put forward an optimization algorithm of triangle grid model based on Laplacian coordinate constraint and a fast reconstruction algorithm of model topology structure based on STL file, such methods may enhance the quality of triangular patch as well as splendidly remain local geometric features of original grid model. The character of it is there’s unnecessary to distinguish constraint vertex and free vertex no longer and to carry on a double restraints to location and Laplacian coordinate for all vertex, then solve a linear system, which contains double restraint, with least-squares sense to carry on an relocation for all vertex. The experimental results showed that proposed algorithm is provided with a certain advantage in terms of detail features of grid compared with precedent Laplacian optimization algorithm.

Assessment and Control of Construction Risk for a Super-Sized Quasi-Rectangular Pipe-Jacking Tunnel Adjacently to High-Speed Railways: A case study

Jianfei Ma,Guangyao Cui,Shaohui He,Xiaokang Ling 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.10

Constructing super-sized quasi-rectangular pipe-jacking tunnels beneath high-speed railways presents a significant risk to both the railways and the tunnels. This paper uses expert inquiry, numerical simulation, fuzzy comprehensive evaluation, and on-site monitoring to assess and control risks for constructing a super-sized quasi-rectangular pipe-jacking tunnel project beneath high-speed railways. An assessment system including 18 factors from 6 aspects is built by integrating existing literature, expert consultation, and causality analysis. As the insufficient number of projects, the Analytic Hierarchy Process (AHP), Fuzzy Comprehensive Evaluation Method (FCEM), Delphi method, and numerical simulation are employed to establish a risk assessment model. The pre-support roof construction (P-SRC) technology is proposed to control tunnel construction risks. The actual scenario on site examines the validity and practicality of the evaluation model and control measures. The results indicate that the super-sized quasi-rectangular pipe-jacking tunnel sections for planned and operational high-speed railways belong to the level I risk, requiring risk reduction measures. The artificial borehole piles + D-shaped beams scheme and pile-plate structure scheme decrease the construction risk from level I to IV, and the evaluated risk results and control effect are in good agreement with actual construction conditions. The proposed risk assessment method and control technology are reasonable and reliable, providing a scientific reference for similar projects.

Load Balancing Algorithm Based on QoS Awareness Applied in Wireless Networks

CHEN Xiangqian,MA Shaohui,Zhao Kai 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.4

In order to reduce business latency and packet loss rate, to improve the throughput of integration of heterogeneous wireless network, to achieve load diversification and to improve end quality of service, while there are many problems on the dropout rate of the traditional load balancing algorithm in processing throughput, delay and business, therefore, gateway load balancing algorithm is proposed in this paper. All terminals in the access network can reflect the effectiveness of the average network load level of the network, this algorithm will gain weight of the load in the network of small business terminal to switch to the network load which is light. First, it defines the heterogeneous networks and network terminal payoff function utility function, which are used to characterize the experience and network QOS terminal load situation, and then presents the specific processes of the gateway load balancing algorithm. Finally, switching decisional load balancing algorithm, proposed by Yan X, etc. is compared with simulation experiments and it shows that: the proposed gateway load balancing algorithm has strong robustness to achieve network load balancing and to achieve a balanced use of network resource.

White Matter Microstructural Similarity and Diversity of Functional Constipation and Constipation-predominant Irritable Bowel Syndrome

( Jiaofen Nan ),( Liangliang Zhang ),( Qiqiang Chen ),( Nannan Zong ),( Peiyong Zhang ),( Xing Ji ),( Shaohui Ma ),( Yuchen Zhang ),( Wei Huang ),( Zhongzhou Du ),( Yongquan Xia ),( Ming Zhang ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2018 Journal of Neurogastroenterology and Motility (JNM Vol.24 No.1

Background/Aims The Rome III criteria separated chronic constipation into functional constipation (FC) and constipation-predominant irritable bowel syndrome (IBS-C), but some researchers questioned the partitioning and treated both as distinct parts of a continuum. The study aims to explore the similarity and diversity of brain white matter between FC and IBS-C. Methods The voxel-wise analysis of the diffusion parameters was used to quantify the white matter changes of female brains in 18 FC patients and 20 IBS-C patients compared with a comparison group with 19 healthy controls by tract-based spatial statistics. The correlations between diffusive parameters and clinical symptoms were evaluated using a Pearson’s correlation. Results In comparison to healthy controls, FC patients showed a decrease of fractional anisotropy (FA) and an increase of radial diffusivity (RD) in multiple major fibers encompassing the corpus callosum (CC, P = 0.001 at peak), external capsule (P = 0.002 at peak), corona radiata (CR, P = 0.001 at peak), and superior longitudinal fasciculus (SLF, P = 0.002 at peak). In contrast, IBS-C patients showed FA and RD aberrations in the CC (P = 0.048 at peak). Moreover, the direct comparison between FC and IBS-C showed only RD differences in the CR and SLF. In addition, FA and RD in the CC were significantly associated with abdominal pain for all patients, whereas FA in CR (P = 0.016) and SLF (P = 0.040) were significantly associated with the length of time per attempt and incomplete evacuation separately for FC patients. Conclusion These results may improve our understanding of the pathophysiological mechanisms underlying different types of constipation. (J Neurogastroenterol Motil 2018;24:107-118)