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FIBER ORIENTATION DISTRIBUTIONS IN SLIT CHANNEL FLOWS WITH ABRUPT EXPANSION FOR FIBER SUSPENSIONS

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Journal of Hydrodynamics 2008年第6期20卷 696-705页

作者： ku xiao-ke LIN Jian-zhong State key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China China Jiliang University Hangzhou 310018 China

The lattice Boltzmann method was used to investigate numerically the fiber orientation distributions in slit channel flows with abrupt expansion for fiber suspensions even in the concentrated regime. The channels have a thin slit geometry with 1：4 and 1：3 expansions. Both the interactions between fibers and that between fibers and channel walls were taken into consideration. Some of numerical results are qualitatively in agreement with the experiment data. It is found that most of fibers are aligned in the flow direction in all the suspensions in the entrance region of the expansion. Fiber orientation distributions, having different patterns in different regions of the flow, depend on the expansion ratio of the channel. The mechanical fiber-fiber interaction largely affects the fiber orientation in the downstream of the expansion and in the salient corner for the cases of concentrated suspensions. The hydrodynamic interaction plays an important role on the fiber orientation in the dilute suspension.

关键词： fiber suspension orientation distributions lattice Boltzmann method slit channel flows with abrupt expansion

Numerical Simulation on Radon Retardation Behavior of Covering Floats in Radon-Containing Water

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Biomedical and Environmental Sciences 2024年第4期37卷 406-417页

作者： LIU Shu Yuan ZHANG Li YE Yong Jun DING ku ke National Institute for Radiological Protection Chinese Center for Disease Control and PreventionBeijing 100088China Office for Public Health Management Chinese Center for Disease Control and PreventionBeijing 102206China key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy University of South ChinaHengyang 421001HunanChina

Objective This study aimed to efficiently reduce the release of radon from water bodies to protect the *** Based on the sizes of the experimental setup and modular float,computational fluid dynamics(CFD)was used to assess the impact of the area coverage rate,immersion depth,diffusion coefficient,and radon transfer velocity at the gas–liquid interface on radon migration and exhalation of radon-containing *** on the numerical simulation results,an estimation model for the radon retardation rate was *** effectiveness of the CFD simulation was evaluated by comparing the experimental and simulated variation values of the radon retardation rate with the coverage area *** The effect of radon transfer velocity on radon retardation in water bodies was minor and insignificant according to the appropriate value;therefore,an estimation model of the radon retardation rate of the coverage of a radon-containing water body was constructed using the synergistic impacts of three factors:area coverage rate,immersion depth,and diffusion *** deviation between the experimental and simulated results was<4.3%.Conclusion Based on the numerical simulation conditions,an estimation model of the radon retardation rate of covering floats in water bodies under the synergistic effect of multiple factors was obtained,which provides a reference for designing covering floats for radon retardation in radoncontaining water.

关键词： Radon-containing water Radon retardation rate CFD Coverage experiment Optimized design

布朗运动和湍流扩散作用下槽流中纤维悬浮流动特性的研究

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物理学报 2016年第19期65卷 177-190页

作者：夏懿库晓珂沈苏华浙江大学航空航天学院力学系杭州310027

为了探讨槽道中纤维悬浮湍流场特性,本文对修正的雷诺平均纳维-斯托克斯方程、含纤维项的湍动能和耗散率方程、纤维动力学方程以及纤维取向概率密度函数方程进行了数值研究,同时进行了相关实验以验证计算结果.研究结果表明,流场中尤其... 详细信息

为了探讨槽道中纤维悬浮湍流场特性,本文对修正的雷诺平均纳维-斯托克斯方程、含纤维项的湍动能和耗散率方程、纤维动力学方程以及纤维取向概率密度函数方程进行了数值研究,同时进行了相关实验以验证计算结果.研究结果表明,流场中尤其是近壁区域,纤维取向趋向于与流动方向一致,且该现象随着雷诺数和纤维浓度的减小以及纤维长径比的增大而更为明显.纤维在槽道中分布不均匀,但随着雷诺数的增大和纤维长径比的减小趋于均匀.相对于单相流,纤维悬浮流的流向平均速度剖面更陡峭,且剖面斜率随着纤维浓度、长径比的增大以及雷诺数的减小而变大,纤维的存在使湍流场的湍动能和雷诺应力减小,且减小程度随着纤维浓度和长径比的增大以及雷诺数的减小而增加.流场中的第一法向应力差小于0.05且远小于剪切应力.从壁面到中心,剪切应力增加而第一法向应力差减小.剪切应力和第一法向应力差都随着纤维浓度和长径比的增大而增大.随着雷诺数的增大,剪切应力增大而第一法向应力差减小.纤维浓度对于剪切应力和第一法向应力差的影响比纤维长径比更显著.

关键词：纤维悬浮流布朗扩散湍流扩散流变特性

Effects of electrothermal ageing on dielectric performance of metallised biaxial orientation polypropylene film capacitors in strong magnetic fields

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High Voltage 2024年第4期9卷 911-919页

作者： Haoliang Liu Boxue Du Meng xiao ke Chen Yanwei Ma School of Electrical and Information Engineering Tianjin UniversityTianjinChina Institute of Electrical Engineering Chinese Academy of SciencesBeijingChina

The dielectric performance of the pristine and the electrothermal-aged metallised polypropylene capacitors are investigated under different magnetic *** energy storage capacity decreases under the magnetic *** 12 T,the capacitance value of the pristine capacitors decreases by 8.4%-17%and that of the aged capacitors declines by 15%-20%.The dielectric loss is reduced by 2.6%-6.3%,but the equivalent series resistance shows an 8.3%-23.1%*** leakage conductivity increases to 202%-354%,which leads to a weakened voltage holding *** addition to the effects of the magnetic fields,the impacts of ageing have also been *** effects of the magnetic field and ageing on the electrical parameters of the capacitors are discussed *** molecular chains of the dielectric are oxidised and decomposed during the ageing process,which reduces the insulating properties of the *** magnetic field inhibits polarisation by changing the polarisation behaviour through Lorentz force and excites the electrons to enhance charge transmission.

关键词： magnetic performance fields

Adsorption and sensing characteristics of insulating gas C4F7N on 3d late transition metal-phthalocyanine:Theoretical and experimental study

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High Voltage 2024年第4期9卷 870-878页

作者： Dachang Chen Ziang Zheng Cong Zhang Yi Luo Song xiao Qing Miao ke Liu Beibei xiao School of Electrical and Electronic Engineering Wuhan Polytechnic UniversityWuhanChina Beijing International S&T Cooperation Base for Plasma Science and Energy Conversion Institute of Electrical EngineeringChinese Academy of SciencesBeijingChina School of Electrical Engineering and Automation Wuhan UniversityWuhanChina School of Energy and Power Engineering Jiangsu University of Science and TechnologyZhenjiangChina

Heptafluoroisobutyronitrile(C_(4)F_(7)N)is being considered as a promising alternative to the greenhouse gas SF6 in the electrical ***,its biotoxicity necessitates the development of gas sensing technology to detect leaked C_(4)F_(7)N.A combination of density functional theory and experiments was employed to evaluate the adsorption and sensing performance of different metal-phthalocyanines as potential sensing materials for C_(4)F_(7)N *** study included exploring adsorption configurations with adsorption energies,electron transfer,and adsorption distance,as well as comparisons of electronic properties,electron distribution,and density of states(DOS)among the ***,gas sensing experiments were conducted using different MPcs to detect 25-100 ppm C_(4)F_(7)*** results revealed that Mn-Pc,Fe-Pc,Co-Pc,and Zn-Pc exhibited considerable chemical interactions,while Ni-Pc and Cu-Pc showed weaker adsorption *** findings were further elucidated based on the electron density and DOS of atomic ***,gas sensing experiments indicated that Co-Pc demonstrated a higher response compared to Fe-Pc at the same concentration of C_(4)F_(7)***,the theoretical and experimental insights offer valuable guidance for C_(4)F_(7)N detection and provide a systematic approach to screen and explore organometallic polymer-based gas sensors applicable in various fields.

关键词： adsorption phthalocyanine Adsorption

A Formal Model for Analyzing Fair Exchange Protocols Based on Event Logic

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Computer Modeling in Engineering & Sciences 2024年第3期138卷 2641-2663页

作者： ke Yang Meihua xiao Zehuan Li School of Electrical Engineering and Automation East China Jiaotong UniversityNanchang330013China School of Software East China Jiaotong UniversityNanchang330013China

Fair exchange protocols play a critical role in enabling two distrustful entities to conduct electronic data exchanges in a fair and secure *** protocols are widely used in electronic payment systems and electronic contract signing,ensuring the reliability and security of network *** order to address the limitations of current research methods and enhance the analytical capabilities for fair exchange protocols,this paper proposes a formal model for analyzing such *** proposed model begins with a thorough analysis of fair exchange protocols,followed by the formal definition of *** definition accurately captures the inherent requirements of fair exchange *** upon event logic,the model incorporates the time factor into predicates and introduces knowledge set *** enhancement empowers the improved logic to effectively describe the state and knowledge of protocol participants at different time points,facilitating reasoning about their acquired *** maximize the intruder’s capabilities,channel errors are translated into the behaviors of the *** participants are further categorized into honest participants and malicious participants,enabling a comprehensive evaluation of the intruder’s potential *** employing a typical fair exchange protocol as an illustrative example,this paper demonstrates the detailed steps of utilizing the proposed model for protocol *** entire process of protocol execution under attack scenarios is presented,shedding light on the underlying reasons for the attacks and proposing corresponding *** developedmodel enhances the ability to reason about and evaluate the security properties of fair exchange protocols,thereby contributing to the advancement of secure network transactions.

关键词： Fair exchange protocols fairness formal analysis logic reasoning

Shear-thinning Catechol-modified Chitosan Hydrogel Loaded with Silver Nanoparticles for Endoscopic Submucosal Dissection

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Chinese Journal of Polymer Science 2024年第8期42卷 1147-1155页

作者： Wen-Jun Feng Yan-He Wu xiao-Yang Liu Zheng-ke Wang MOE key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou 310058China

Shear-thinning hydrogels have emerged for endoscopic submucosal dissection,while wound intervention after surgery has rarely been ***,a catechol-modified chitosa n hydrogel with shear-thinning property was developed for simultaneously facilitating endoscopic submucosal dissection and postoperative wound *** from the shear-thinning and self-healing characteristics,the asprepared hydrogel showed easily endoscopic *** also performed very well as submucosal cushion,which could remain above 70%after injection for 120 min in ex vivo porcine large intestine *** fact,the cushion height of normal saline dramatically decreased to 46%of the initial height at 30 *** nanoparticles encapsulated into the network endowed the hydrogel with almost reached 100%antibacterial effect against *** and *** hemolysis ratio of the hydrogel was calculated to be as low as 0.8%.Combined with good hemocompatibility and cytocompatibility,the as-prepared hydrogel displayed much higher in vivo wound closu re and healing efficacy than normal *** results demonstrated the superiority of the shear-thinning chitosan hydrogel in facilitating clinical endoscopic submucosal dissection surgery.

关键词： Shear-thinning hydrogel Endoscopic mucosal dissection Wound healing Catechol-modified chitosan Silver nanoparticles

New clinical trial design in precision medicine:discovery,development and direction

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Signal Transduction and Targeted Therapy 2024年第4期9卷 1293-1321页

作者： xiao-Peng Duan Bao-Dong Qin xiao-Dong Jiao ke Liu Zhan Wang Yuan-Sheng Zang Department of Medical Oncology Changzheng HospitalNaval Medical UniversityShanghaiChina

In the era of precision medicine,it has been increasingly recognized that individuals with a certain disease are complex and different from each *** to the underestimation of the significant heterogeneity across participants in traditional"one-sizefits-all"trials,patient-centered trials that could provide optimal therapy customization to individuals with specific biomarkers were developed including the basket,umbrella,and platform trial designs under the master protocol *** recent years,the successive FDA approval of indications based on biomarker-guided master protocol designs has demonstrated that these new clinical trials are ushering in tremendous *** the rapid increase in the number of basket,umbrella,and platform trials,the current clinical and research understanding of these new trial designs,as compared with traditional trial designs,remains *** majority of the research focuses on methodologies,and there is a lack of in-depth insight concerning the underlying biological logic of these new clinical trial ***,we provide this comprehensive review of the discovery and development of basket,umbrella,and platform trials and their underlying logic from the perspective of precision ***,we discuss future directions on the potential development of these new clinical design in view of the"Precision Pro","Dynamic Precision",and"Intelligent Precision".This review would assist trial-related researchers to enhance the innovation and feasibility of clinical trial designs by expounding the underlying logic,which be essential to accelerate the progression of precision medicine.

关键词： clinical approval successive

Scene text recognition via dual character counting-aware visual and semantic modeling network

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Science China(Information Sciences) 2024年第3期67卷 313-314页

作者： ke xiao Anna ZHU Brian kenji IWANA Cheng-Lin LIU School of Computer Science and Artificial Intelligence Wuhan University of Technology Human Interface Laboratory Kyushu University State key Laboratory of Multimodal Artificial Intelligence Systems Institute of AutomationChinese Academy of Sciences School of Artificial Intelligence University of Chinese Academy of Sciences

Scene text recognition(STR) is drawing increasing attention nowadays due to its wide application in real life. Character counting information, as auxiliary information, has been shown to be effective in boosting text ... 详细信息

关键词： Decoding