• Title/Summary/Keyword: Xue effect

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Total pressure dependence of YBCO films in MOD method (MOD 공정에 의해 제조된 YBCO 박막의 압력 의존성)

  • Yoo, Jai-Moo;Chung, Kook-Chae;Ko, Jae-Woong;Kim, Young-Kuk;Wang, Xiao Lin;Dou, Shi Xue
    • Progress in Superconductivity and Cryogenics
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    • v.8 no.1
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    • pp.5-8
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    • 2006
  • The growth properties of MOD-YBCO films were investigated. To enhance the growth rate of YBCO layer and inhibit the build-up of HF gas during the annealing process in TFA-MOD for YBCO coated conductors the method of low pressure annealing was employed. Total pressure was changed from 700Torr to 1Torr and its effect on growth of YBCO films was compared with atmospheric one. The lower Pressure was effective to control of the pore size in MOD method . Surface morphology of YBCO films processed at low total pres sure was rough and composed of random YBCO (103) grains. But large pores, usually observed at atmospheric process in MOD disappeared and also the number of pores was reduced at low pressure annealing. Also discussed ate the effects of Fluorine-free Y and Cu precursor solution on the development of microstructure. Dense surface me phology and with less and small pores can be provided through controlling Fluorine content.

Technique of grouting in silty-fine sand with abundant water: Practice in Beijing

  • Liu, Jun;Zhang, Liang;Xue, Hongsong;You, Tian;Wu, Yuqian
    • Geomechanics and Engineering
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    • v.29 no.4
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    • pp.463-470
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    • 2022
  • In NATM tunnels, water inrush and tunnel collapse are often encountered in silty-fine sand with abundant water during excavation. Because of the special engineering properties of this stratum, grouting effect is difficult to achieve as expected, and it is a major problem in the field of civil engineering. Taking Beijing Metro Line 10 as a case, we applied PFC3D to simulate the process of grouting in this stratum. By analyzing the law of grout diffusing and porosity change under different grouting pressures, the study found that grouting was a process of splitting, and grouting pressure played an important role. The numerical results were verified by theoretical calculation analysis, and the grouting parameters were determined under the various grouting pressures for practice. After the excavation of this tunnel, the concretions in silty-fine sand are similar to the results of PFC3D simulation, which indicates that the grouting mechanism is confirmed by field observation further.

Digital Transformation, Manipulation of Asset Evaluation and M&A Performance: Discussion on the Intermediary Effect of Internal Control

  • Chen Chen;Hee-Jung Lee;Nan Hui;Xue-Hua Qian
    • Asia-Pacific Journal of Business
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    • v.14 no.1
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    • pp.1-19
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    • 2023
  • Purpose - The purpose of this study was to examine the internal relevance between digital transformation, manipulation of asset evaluation and corporate M&A performance and further explores the impact path of manipulation of asset valuation on corporate M&A performance. Design/methodology/approach - This study based on the financial data of A-share listed companies in Shanghai and Shenzhen Stock Exchanges from 2013 to 2021. Findings - First, manipulation of asset evaluation is negatively correlated with M&A performance. Second, Digital transformation significantly weakens the negative correlation between manipulation of asset evaluation and corporate M&A performance. Third, The effectiveness of internal control plays a partially intermediary role in the process of manipulation of asset evaluation affecting M&A performance. Research implications or Originality - Enriching the existing literature on the subject, the study can also provide useful reference for improving the performance of corporate mergers and acquisitions, regulating asset valuation, promoting the digital transformation of enterprises and improving internal control mechanisms, with both theoretical and practical implications.

A numerical framework of the phenomenological plasticity and fracture model for structural steels under monotonic loading

  • He, Qun;Yam, Michael C.H.;Xie, Zhiyang;Lin, Xue-Mei;Chung, Kwok-Fai
    • Steel and Composite Structures
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    • v.44 no.4
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    • pp.587-602
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    • 2022
  • In this study, the classical J2 flow theory is explicitly proved to be inappropriate to describe the plastic behaviour of structural steels under different stress states according to the reported test results. A numerical framework of the characterization of the strain hardening and ductile fracture initiation involving the effect of stress states, i.e., stress triaxiality and Lode angle parameter, is proposed based on the mechanical response of structural steels under monotonic loading. Both effects on strain hardening are determined by correction functions, which are implemented as different modules in the numerical framework. Thus, other users can easily modify them according to their test results. Besides, the ductile fracture initiation is determined by a fracture locus in the space of stress triaxiality, Lode angle parameter, and fracture strain. The numerical implementation of the proposed model and the corresponding code are provided in this paper, which are also available on GitHub. The validity of the numerical procedure is examined through single element tests and the accuracy of the proposed model is verified by existing test results.

Real Scene Text Image Super-Resolution Based on Multi-Scale and Attention Fusion

  • Xinhua Lu;Haihai Wei;Li Ma;Qingji Xue;Yonghui Fu
    • Journal of Information Processing Systems
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    • v.19 no.4
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    • pp.427-438
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    • 2023
  • Plenty of works have indicated that single image super-resolution (SISR) models relying on synthetic datasets are difficult to be applied to real scene text image super-resolution (STISR) for its more complex degradation. The up-to-date dataset for realistic STISR is called TextZoom, while the current methods trained on this dataset have not considered the effect of multi-scale features of text images. In this paper, a multi-scale and attention fusion model for realistic STISR is proposed. The multi-scale learning mechanism is introduced to acquire sophisticated feature representations of text images; The spatial and channel attentions are introduced to capture the local information and inter-channel interaction information of text images; At last, this paper designs a multi-scale residual attention module by skillfully fusing multi-scale learning and attention mechanisms. The experiments on TextZoom demonstrate that the model proposed increases scene text recognition's (ASTER) average recognition accuracy by 1.2% compared to text super-resolution network.

Nonlinear vibration analysis of FG porous shear deformable cylindrical shells covered by CNTs-reinforced nanocomposite layers considering neutral surface exact position

  • Zhihui Liu;Kejun Zhu;Xue Wen;Abhinav Kumar
    • Advances in nano research
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    • v.17 no.1
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    • pp.61-73
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    • 2024
  • This paper presents nonlinear vibration analysis of a composite cylindrical shell. The core of the shell is made of functionally graded (FG) porous materials and layers is fabricated of carbon nanotubes (CNTs) reinforced nanocomposites. To increase the accuracy of results, neutral surface position is considered. First-order shear deformation theory is used as displacement field to derive the basic relations of equation motions. In addition, von-Karman nonlinear strains are employed to account geometric nonlinearity and to enhance the results' precision, the exact position of the neutral surface is considered. To governing the partial equations of motion, the Hamilton's principle is used. To reduce the equation motions into a nonlinear motion equation, the Galerkin's approach is employed. After that the nonlinear motion equation is solved by multiple scales method. Effect of various parameters such as volume fraction and distribution of CNTs along the thickness directions, different patterns and efficiency coefficients of porous materials, geometric characteristics and initial conditions on nonlinear to linear ratio of frequency is investigated.

Unsteady aerodynamic force on a transverse inclined slender prism using forced vibration

  • Zengshun Chen;Jie Bai;Yemeng Xu;Sijia Li;Jianmin Hua;Cruz Y. Li;Xuanyi Xue
    • Wind and Structures
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    • v.37 no.5
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    • pp.331-346
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    • 2023
  • This work investigates the effects of transverse inclination on an aeroelastic prism through forced-vibration wind tunnel experiments. The aerodynamic characteristics are tri-parametrically evaluated under different wind speeds, inclination angles, and oscillation amplitudes. Results show that transverse inclination fundamentally changes the wake phenomenology by impinging the fix-end horseshoe vortex and breaking the separation symmetry. The aftermath is a bi-polar, one-and-for-all change in the aerodynamics near the prism base. The suppression of the horseshoe vortex unleashes the Kármán vortex, which significantly increases the unsteady crosswind force. After the initial morphology switch, the aerodynamics become independent of inclination angle and oscillation amplitude and depend solely on wind speed. The structure's upper portion does not feel the effect, so this phenomenon is called Base Intensification. The phenomenon only projects notable impacts on the low-speed and VIV regime and is indifferent in the high-speed. In practice, Base Intensification will disrupt the pedestrian-level wind environment from the unleashed Bérnard-Kármán vortex shedding. Moreover, it increases the aerodynamic load at a structure base by as much as 4.3 times. Since fix-end stiffness prevents elastic dissipation, the load translates to massive stress, making detection trickier and failures, if they are to occur, extreme, and without any warnings.

Enhanced supply of methionine regulates protein synthesis in bovine mammary epithelial cells under hyperthermia condition

  • Zhou, Jia;Yue, Shuangming;Xue, Benchu;Wang, Zhisheng;Wang, Lizhi;Peng, Quanhui;Xue, Bai
    • Journal of Animal Science and Technology
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    • v.63 no.5
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    • pp.1126-1141
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    • 2021
  • Recent evidence has shown that methionine (Met) supplementation can improve milk protein synthesis under hyperthermia (which reduces milk production). To explore the mechanism by which milk protein synthesis is affected by Met supplementation under hyperthermia, mammary alveolar (MAC-T) cells were incubated at a hyperthermic temperature of 42℃ for 6 h in media with different concentrations of Met. While the control group (CON) contained a normal amino acid concentration profile (60 ㎍/mL of Met), the three treatment groups were supplemented with Met at concentrations of 10 ㎍/mL (MET70, 70 ㎍/mL of Met), 20 ㎍/mL (MET80, 80 ㎍/mL of Met), and 30 ㎍/mL (MET90,90 ㎍/mL of Met). Our results show that additional Met supplementation increases the mRNA and protein levels of BCL2 (B-cell lymphoma-2, an anti-apoptosis agent), and decreases the mRNA and protein levels of BAX (Bcl-2-associated X protein, a pro-apoptosis agent), especially at an additional supplementary concentration of 20 ㎍/mL (group Met80). Supplementation with higher concentrations of Met decreased the mRNA levels of Caspase-3 and Caspase-9, and increased protein levels of heat shock protein (HSP70). The total protein levels of the mechanistic target of rapamycin (mTOR) and the mTOR signalling pathway-related proteins, AKT, ribosomal protein S6 kinase B1 (RPS6KB1), and ribosomal protein S6 (RPS6), increased with increasing Met supplementation, and peaked at 80 ㎍/mL Met (group Met80). In addition, we also found that additional Met supplementation upregulated the gene expression of αS1-casein (CSN1S1), β-casein (CSN2), and the amino acid transporter genes SLC38A2, SLC38A3 which are known to be mTOR targets. Additional Met supplementation, however, had no effect on the gene expression of κ-casein (CSN3) and solute carrier family 34 member 2 (SLC34A2). Our results suggest that additional Met supplementation with 20 ㎍/mL may promote the synthesis of milk proteins in bovine mammary epithelial cells under hyperthermia by inhibiting apoptosis, activating the AKT-mTOR-RPS6KB1 signalling pathway, and regulating the entry of amino acids into these cells.

The impact of Foreign direct investment on Energy intensity: absorptive capacity as moderator (외국인 직접투자가 에너지 집약도에 미치는 영향분석-흡수능력의 조절효과를 중심으로)

  • Wang, Xiao Xue;Hwang, Yun-Seop
    • International Commerce and Information Review
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    • v.16 no.5
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    • pp.179-201
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    • 2014
  • The complementary effect between FDI and its absorptive capacity has drawn more attention than before. This paper intended to explore the relationship between energy intensity and such complementary effect. The absorptive capacity of FDI shows various aspects among which we focus on the human capital, the financial system and the infrastructure in this paper. Using the panel data from 1990 to 2011, the study is processed between the 20 OECD and 20 Non-OECD countries. The empirical results shown that for OECD country, a complementary effect exists between FDI and its absorbability and it has the controlling effect on energy reduction. But the effect is only significant in the human capital and the financial system. The infrastructure variable is less important in OECD country due to their high development level. However, for non-OECD country, the complementary effect between infrastructure and FDI reduces energy consumption significantly, it can get to the point that the process for infrastructure to attract FDI and also benefits from it only blow its way to the Non-OECD, developing countries, without andy special effects for the OECD countries which has already highly build up their infrastructure. Also, the financial system in Non-OECD countries is at the primary stage yet, which is not easy to contribute efficiency. To make a conclusion, the complementary effect between infrastructure and FDI in OECD country and which between finical system and FDI in non-OECD country cannot enhance energy efficiency as expected.

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Experimental study on shear performance of partially precast Castellated Steel Reinforced Concrete (CPSRC) beams

  • Yang, Yong;Yu, Yunlong;Guo, Yuxiang;Roeder, Charles W.;Xue, Yicong;Shao, Yongjian
    • Steel and Composite Structures
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    • v.21 no.2
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    • pp.289-302
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    • 2016
  • A new kind of partially precast or prefabricated castellated steel reinforced concrete beam, which is abbreviated here as CPSRC beam, was presented and introduced in this paper. This kind of CPSRC beam is composed of a precast outer-part and a cast-in-place inner-part. The precast outer-part is composed of an encased castellated steel shape, reinforcement bars and high performance concrete. The cast-in-place inner-part is made of common strength concrete, and is casted with the floor slabs simultaneously. In order to investigate the shear performance of the CPSRC beam, experiments of six CPSRC T-beam specimens, together with experiments of one cast-in-place SRC control T-beam specimen were conducted. All the specimens were subjected to sagging bending moment (or positive moment). In the tests, the influence of casting different strength of concrete in the cross section on the shear performance of the PPSRC beam was firstly emphasized, and the effect of the shear span-to-depth ratio on that were also especially taken into account too. During the tests, the shear force-deflection curves were recorded, while the strains of concrete, the steel shapes as well as the reinforcement stirrups at the shear zone of the specimens were also measured, and the crack propagation pattern together with the failure pattern was as well observed in detail. Based on the test results, the shear failure mechanism was clearly revealed, and the effect of the concrete strength and shear span-to-depth ratios were investigated. The shear capacity of such kind of CPSRC was furthermore discussed, and the influences of the holes on the steel shape on the shear performance were particularly analyzed.