Experimental and Mechanical Behavior of Rubber-Sleeved Group Studs

Yuxuan Chen,Quansheng Yan,Buyu Jia,Xiaolin Yu,Yu Wu,Yufan Luo 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.9

The group studs used in precast steel-concrete composite bridges can reduce the volume of cast-in-place concrete, consequently accelerating the construction process and improving the construction quality. However, the small spacing of the studs in the group studs may result in a decrease in shear strength and ductility, and a nonuniform distribution of shear force at the root of the studs. Hence, rubber-sleeved group studs, whose studs are wrapped by a rubber sleeve at the root, are proposed to redistribute the shear force at the steel–concrete interface and improve the ductility of the shear connector. In this study, four push-out tests were conducted to demonstrate the composite mechanism of rubber-sleeved group studs. Results show that the rubber-sleeved group studs exhibit better ductility than ordinary group studs. Finite element models verified using the test results were also established for parametric analysis. The mechanism analysis shows that the concrete compression regions around stud roots are sufficiently utilized. Based on the parametric analysis, designing suggestions for rubber-sleeved group studs were provided.

Experimental and Numerical Research on Uplift-Restricted and Slip-Permitted Screw-Shaped Connectors

Yuxuan Chen,Quansheng Yan,Xiaolin Yu,Buyu Jia,Yu Wu,Yufan Luo 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.1

Improving mechanical performance of the negative moment regions of continuous composite beams is essential for composite beam bridges. Uplift-restricted and slip-permitted (URSP) screw-shaped connectors can enhance the crack resistance of a concrete slab through free slip between the concrete slab and the steel beam. Furthermore, URSP screw-shaped connectors are more adaptable to the requirements of rapid construction than URSP T-shaped connectors. To investigate the slip and mechanical behavior of URSP screw-shaped connectors, nine push-out tests with various parameters were conducted. In these tests, the thickness of the foam sleeve wrapped outside the screw exerted a highly signifi cant eff ect on free slip performance. A refi ned 3D nonlinear fi nite element model with the foam’s constitutive model was established using ABAQUS. The stress mechanism and failure modes of the FE models were analyzed. Lastly, to estimate the slip performance of URSP screw-shaped connectors, an equation with a simple form was proposed via mechanism analysis and a regression method.

Optimized interfacial compatibility of carbon fiber and epoxy resin via controllable thickness and activated ingredients of polydopamine layer

Wu Dongliang,Xing Yuxuan,Zhang Denglu,Hao Zhenna,Dong Qi,Han Yongqin,Liu Lei,Wang Maoju,Zhang Ruliang 한국탄소학회 2024 Carbon Letters Vol.34 No.1

In this work, the trend in the performance of carbon fiber (CF) and its composite during self-polymerization of polydopamine (PDA) at carbon fiber surface was investigated by varying the self-polymerization time of dopamine in an aqueous solution. Research has shown that the PDA coating elevated the surface roughness and polarity of the inert fiber. The tensile strength of single carbon fiber was significantly improved, especially after 9 h of polydopamine self-polymerization, increasing by 18.64% compared with that of desized carbon fiber. Moreover, the interlaminar shear strength (ILSS) of CF-PDA9-based composites was 35.06% higher than that of desized CF-based composites. This research will provide a deep insight into the thickness and activated ingredients of dopamine oxidation and self-polymerization on interfacial compatibility of carbon fiber/epoxy resin composites.

Diagnostic performance of ultrasound risk stratification systems on thyroid nodules cytologically classified as indeterminate: a systematic review and meta-analysis

Zhichao Xing,Yuxuan Qiu,Jingqiang Zhu,Anping Su,Wenshuang Wu 대한초음파의학회 2023 ULTRASONOGRAPHY Vol.42 No.4

Purpose: Ultrasound (US) risk stratification systems (RSSs) are increasingly being utilized for the optimal management of thyroid nodules, including those with indeterminate cytology. The goal of this study was to evaluate the category-based diagnostic performance of US RSSs in identifying malignancy in indeterminate nodules. Methods: This systematic review and meta-analysis was registered on PROSPERO (CRD42021266195). PubMed, EMBASE, and Web of Science were searched through December 1, 2022. Original articles reporting data on the performance of US RSSs for indeterminate nodules were included. The numbers of nodules classified as true negative, true positive, false negative, and false positive were extracted. Results: Thirty-three studies evaluating 7,225 indeterminate thyroid nodules were included. The diagnostic accuracy was quantitatively synthesized using a Bayesian bivariate model based on the integrated nested Laplace approximation in R. For the intermediate- to high-risk category, the sensitivity levels of the American College of Radiology, the American Thyroid Association, the European Thyroid Association, the Korean Thyroid Association/Korean Society of Thyroid Radiology, and Kwak et al. were found to be 0.80, 0.72, 0.76, 0.96, and 0.97, respectively. The corresponding specificity measurements were 0.36, 0.50, 0.49, 0.28, and 0.17. Furthermore, for the high-risk category, the sensitivity values were 0.40, 0.46, 0.55, 0.47, and 0.10, while the specificity levels were 0.91, 0.90, 0.71, 0.91, and 0.99, respectively. Conclusion: The overall diagnostic performance of the US RSSs was moderate in the differentiation of indeterminate nodules.

Transcriptomic profiling of the cold stress and recovery responsiveness of two contrasting Guizhou HE rice genotypes

Wang Zhongni,Wu Xian,Chen Yuxuan,Wu Chaoxin,Long Wuhua,Zhu Susong 한국유전학회 2023 Genes & Genomics Vol.45 No.4

Background At the seed germination stage, rice is sensitive to cold stress, which adversely affects its growth and development. Guizhou HE rice comprises several different landraces, most of which are cold tolerant. Objective To identify differentially expressed genes and molecular mechanism underlying the cold tolerance of Guizhou HE. Methods Two Guizhou HE genotypes, AC44 (cold-sensitive) and AC96 (cold-tolerant), which exhibit opposite phenotypes in response to cold treatment at the seed germination stage were used. Comprehensive gene expressions of AC44 and AC96 under 4 °C cold treatment and subsequent recovery conditions were comparatively analyzed by RNA sequencing. Results Overall, 11,082 and 7749 differentially expressed genes were detected in AC44 and AC96, respectively. Comparative transcriptome analysis demonstrated that, compared with AC44, AC96 presented fewer upregulated and downregulated genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses demonstrated that AC96 presented more upregulated GO terms, especially terms associated with biological processes. However, AC44 presented more terms related to cellular components, mainly chloroplasts. Moreover, DEGs related to the auxin signaling pathway (including ARF and IAA family members) and transcription factors (including members of the F-box, bZIP, basic helix-loop-helix [bHLH], and MYB-like transcription factor families) were found to be expressed specifically in AC96; thus, these DEGs may be responsible for the cold tolerance of AC96. Conclusions These findings present information about the cold tolerance mechanism of Guizhou HE rice at the germination stage, providing valuable resources and candidate genes for breeding cold-tolerant rice genotypes.

Artificial Intelligence in the Prediction of Gastrointestinal Stromal Tumors on Endoscopic Ultrasonography Images: Development, Validation and Comparison with Endosonographers

Lu Yi,Wu Jiachuan,Hu Minhui,Zhong Qinghua,Er Limian,Shi Huihui,Cheng Weihui,Chen Ke,Liu Yuan,Qiu Bingfeng,Xu Qiancheng,Lai Guangshun,Wang Yufeng,Luo Yuxuan,Mu Jinbao,Zhang Wenjie,Zhi Min,Sun Jiachen 거트앤리버 소화기연관학회협의회 2023 Gut and Liver Vol.17 No.6

Background/Aims: The accuracy of endosonographers in diagnosing gastric subepithelial lesions (SELs) using endoscopic ultrasonography (EUS) is influenced by experience and subjectivity. Artificial intelligence (AI) has achieved remarkable development in this field. This study aimed to develop an AI-based EUS diagnostic model for the diagnosis of SELs, and evaluated its efficacy with external validation. Methods: We developed the EUS-AI model with ResNeSt50 using EUS images from two hospitals to predict the histopathology of the gastric SELs originating from muscularis propria. The diagnostic performance of the model was also validated using EUS images obtained from four other hospitals. Results: A total of 2,057 images from 367 patients (375 SELs) were chosen to build the models, and 914 images from 106 patients (108 SELs) were chosen for external validation. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the model for differentiating gastrointestinal stromal tumors (GISTs) and non-GISTs in the external validation sets by images were 82.01%, 68.22%, 86.77%, 59.86%, and 78.12%, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in the external validation set by tumors were 83.75%, 71.43%, 89.33%, 60.61%, and 80.56%, respectively. The EUS-AI model showed better performance (especially specificity) than some endosonographers. The model helped improve the sensitivity, specificity, and accuracy of certain endosonographers. Conclusions: We developed an EUS-AI model to classify gastric SELs originating from muscularis propria into GISTs and non-GISTs with good accuracy. The model may help improve the diagnostic performance of endosonographers. Further work is required to develop a multi-modal EUS-AI system.

Effect of P3HT passivation layer on triple cation organic-inorganic hybrid perovskite memristor

Wang Yucheng,Xiong Yuxuan,Wang Hongsu,Wu Xiang,Sha Jian,Shang Yueyang,Zhang Yongqi,Li Wei,Wang Shaoxi 한국물리학회 2023 Current Applied Physics Vol.47 No.-

Triple cation organic-inorganic hybrid perovskite (TCP) memristor is a novel candidate for artificial visual applications due to the integrating of recognition, storage, and computing. However, concerns remain regarding the moisture-induced degradation and thermal stability. Here, P3HT was deposited on the TCP film to optimize the memristor performance which showed better film surface quality and lower power consumption. When the thickness of the P3HT layer increases, the grain boundary of the TCP film was gradually filled, leading to the inhibition of the ions/vacancies drifting, and thus the device type was changed from digital to analog. Besides, various functions are demonstrated in TCP photoelectric memristor including excitatory postsynaptic current under optic and electric stimulations and spike rate-dependent plasticity, proving the great application prospects in numerical calculation and information perception.

Homogenized cross-section generation for pebble-bed type high-temperature gas-cooled reactor using NECP-MCX

Qin Shuai,Li Yunzhao,He Qingming,Cao Liangzhi,Wang Yongping,Wu Yuxuan,Wu Hongchun 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.9

In the two-step analysis of Pebble-Bed type High-Temperature Gas-Cooled Reactor (PB-HTGR), the lattice physics calculation for the generation of homogenized cross-sections is based on the fuel pebble. However, the randomly-dispersed fuel particles in the fuel pebble introduce double heterogeneity and randomness. Compared to the deterministic method, the Monte Carlo method which is flexible in geometry modeling provides a high-fidelity treatment. Therefore, the Monte Carlo code NECP-MCX is extended in this study to perform the lattice physics calculation of the PB-HTGR. Firstly, the capability for the simulation of randomly-dispersed media, using the explicit modeling approach, is developed in NECP-MCX. Secondly, the capability for the generation of the homogenized cross-section is also developed in NECP-MCX. Finally, simplified PB-HTGR problems are calculated by a two-step neutronics analysis tool based on Monte Carlo homogenization. For the pebble beds mixed by fuel pebble and graphite pebble, the bias is less than 100 pcm when compared to the high-fidelity model, and the bias is increased to 269 pcm for pebble bed mixed by depleted fuel pebble. Numerical results show that the Monte Carlo lattice physics calculation for the two-step analysis of PB-HTGR is feasible.