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Effects of particle fractions on the Bingham yield stress and viscosity of fine-coarse particle suspensions

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Journal of Mountain Science 2021年第11期18卷 2960-2970页

作者： DEY Litan jan chyan-deng WANG Ji-Shang Department of Hydraulic and Ocean Engineering National Cheng Kung UniversityTainan 701Chinese Taipei Ecological Soil and Water Conservation Research Center National Cheng Kung UniversityTainan 701Chinese Taipei

The rheological behaviors of highly concentrated fine particle suspensions(clay-silt-water mixtures)and coarse particle suspensions(coarse particles within a fine particle suspension)were investigated in this study.Experimental results demonstrated that the Bingham Fluid Model with two rheological parameters,Bingham yield stressand viscosity,wellcharacterized the rheological behavior of fine particle suspensions at shear rates between 4 and 20 s^(-1).The inclusion of coarse particles within a fine particle suspension induced an enhancement to the rheological parameters.The rheological parameters of a coarse particle suspension not only depend on its total particle fraction but also on its relative fine/coarse particle fractions.Empirical equations of these two parameters were proposed,quantitatively related to both fine and coarse particle fractions.Results indicated that the Bingham yield stress and viscosity are much more(an order larger)sensitive to changes in fine particle fraction than to changes in coarse particle fraction.

关键词： Coarse particle suspension Bingham Fluid Model Particle fractions Rheologicalparameters

Numerical Simulation on a Tremendous Debris Flow Caused by Typhoon Morakot in the Jiaopu Stream,Taiwan

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Journal of Mountain Science 2014年第1期11卷 1-18页

作者： HSU Yu-chao YEN Haw TSENG Wen-hsiao jan chyan-deng Department of Hydraulic and Ocean Engineering National Cheng Kung University Blackland Research and Extension Center Texas A&M AgriLife Research Sun-Rise Engineering Consultant Company

In August 2009,Typhoon Morakot brought a large amount of rainfall with both high intensity and long duration to a vast area of Taiwan.Unfortunately,this resulted in a catastrophic landslide in Hsiaolin Village,Taiwan.Meanwhile,large amounts of landslides were formed in the Jiaopu Stream watershed near the southeast part of the Hsiaolin Village.The Hsiaolin Village access road(Provincial Highway No.21 and Bridge No.8) was completely destroyed by the landslide and consequent debris flow.The major scope of this study is to apply a debris flow model to simulate the disaster caused by the debris flow that occurred in the Jiaopu Stream during Typhoon Morakot.According to the interviews with local residents,this study applied the destruction time of Bridge No.8 and Chen's house to verify the numerical debris flow model.By the spatial rainfall distributions information,the numerical simulations of the debris flow are conducted in two stages.In the first stage(before the landslide-dam failure),the elevation of the debris flow and the corresponding potential damages toward residential properties were investigated.In the second stage(after the landslidedam failure),comparisons of simulation results between the longitudinal and cross profiles of the Jiaopu Stream were performed using topographic maps and satellite imagery.In summary,applications of the adopted numerical debris flow model have shown positive impact on supporting better understanding of the occurrence and movement of debris flow processes.

关键词： Typhoon Morakot Debris flow Numerical simulation Jiaopu Stream Hsiaolin Village

Etching Mechanism of Ti_(3)C_(2)Cl_(2) MXene Phases by CuCl_(2)-Lewis Molten Salt Method

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Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 863-868页

作者：严明 ZHU Yu HUANG Jiangtao CHEN Haoyu deng Yuxiao CHEN Yanlin 王娟 jan-Michael Albina Hubei Provincial Key Laboratory of Green Materials for Light Industry Hubei University of TechnologyWuhan 430068China New Materials and Green Manufacturing Talent Introduction and Innovation Demonstration Base Hubei University of TechnologyWuhan 430068China Hubei Longzhong Laboratory Xiangyang 441000China

We described a method for obtaining fluorine-free Ti_(3)C_(2)Cl_(2)MXene phases by melting copper in CuCl_(2)instead of aluminum in Ti_(3)AlC_(2).XRD results show that when molten salt CuCl_(2)etches Ti_(3)AlC_(2),it forms an intermediate product Ti_(3)CuC_(2),and then reacts with Ti_(3)CuC_(2)to obtain Ti_(3)C_(2)Cl_(2).The reaction of Ti_(3)AlC_(2)and CuCl_(2)at a temperature of 800℃for 2 h to obtain Ti_(3)C_(2)Cl_(2)with an optimal lamellar structure is shown in SEM results.The pseudopotential plane-wave(PP-PW)method is used to calculate on the electronic structure.The etching mechanism is investigated by the total energies of each substance.The chemical reaction of Ti_(3)AlC_(2)and CuCl_(2)will first become Ti_(3)CuC_(2)and Cu,and then become Ti_(3)C_(2)Cl_(2)during the Lewis acid etching process,which are consistent with the experimental results.

关键词： molten salt method CuCl_(2) MXene first-principles calculations etching mechanism

Intermittent slipping of landslide regulated by dilatancy evolution and velocity-weakening friction law: an efficient numerical scheme

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Journal of Mountain Science 2016年第8期13卷 1333-1344页

作者： jan chyan-deng YANG Ray-yeng HWUNG Hwung-hweng CHEN Wen-yau Department of Hydraulic & Ocean Engineering National Cheng Kung University International Wave Dynamics Research Center National Cheng Kung University

When a block of dense sandy soil moves downhill, the shear-induced soil dilatancy along the basal shear boundary produces a negative value of excess pore pressure that increases the basal frictional resistance. Dilatancy angle,Ψ, the degree to which the basal soil dilates due to the shear, normally evolves during slope failure. A study by other researchers shows that if Ψ is constant, the block of dense soil will remain stable(or unstable) sliding when the velocity-weakening rate of the basal friction coefficient of the block is small(or large) enough. Moreover, during unstable sliding processes, the block of dense soil exhibits "periodic" patterns of intermittent slipping. Here, we used a more efficient and accurate numerical scheme to revisit that study. We expanded their model by assuming Ψ evolves during slope failure. Consequently, we acquired completely different results. For instance, even though the velocity-weakening rate of the friction coefficient is fixed at the same smaller(or larger) value that those researchers use, the stable(or unstable) steady states of landslide they predict will inversely change to unstable(or stable) when Ψ decreases(or increases) with the increase of slide displacement to a value small(or large) enough. Particularly, in unstable processes, the soil block exhibits "aperiodic" styles of intermittent slipping, instead of "periodic". We found out that the stick states appearing later last longer(or shorter) in the case of decreasing(or increasing) Ψ. Moreover, because the basic states of landslides with impacts of dilatancy evolution are not steady nor periodic, traditional stability-analysis methods cannot be "directly" used to analyze the stability of such landslides. Here, we broke through this technical problem to a degree. We showed that combining a concept called "quasi-steady-state approximation" with a traditional stability-analysis technique can qualitatively predict the instability onset of the landslides. Through this study, we demonstrated that the combination of Che

关键词：基底摩擦系数滑动速度山体滑坡数值方法间歇性弱化扩容 Chebyshev

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过程分析技术在中药制造工业中的应用

中国中药杂志 2024年第9期49卷 2299-2307页

作者：朱卫丰沈玉邓攀费翼城肖志强钟志坚江西中医药大学现代中药制剂教育部重点实验室江西南昌330004 江中药业股份有限公司江西南昌330096 江西省中药制造过程质量控制技术创新中心江西南昌330004

在中药制造工业中,质量控制决定药品的安全性、有效性及质量的稳定性。而传统质量控制方式一般在批生产结束后对药品进行抽样离线检测,这种方式不仅缺乏全面性,且不能及时发现生产环节中存在的问题。过程分析技术(process analysis tech... 详细信息

在中药制造工业中,质量控制决定药品的安全性、有效性及质量的稳定性。而传统质量控制方式一般在批生产结束后对药品进行抽样离线检测,这种方式不仅缺乏全面性,且不能及时发现生产环节中存在的问题。过程分析技术(process analysis technology, PAT)采用过程检测、数学建模、数据分析等技术对中药制剂生产各个环节的关键质量属性(critical quality attributes, CQA)进行实时收集、分析、反馈、控制以及持续改进。PAT在中药制造工业中的应用是近年来研究的热点之一,其对中药制剂生产质量控制具有实时性、系统性、无损绿色、整体快速检测等优势,可有效保障中药制剂质量的稳定性、提高生产效率,并对中药量-质传递规律研究具有关键作用。常用的PAT有近红外光谱、拉曼光谱、在线微波等,运用PAT建立在线检测模型是中药生产实现智能制造的关键基础性工作;通过PAT获得实时在线检测数据并以此为基础建立闭环控制模型是行业的关键共性技术难点。该文采用系统文献分析法总结归纳了国内外相关文献、政策法规以及生产应用等,对过程分析技术的发展趋势以及实际应用情况进行介绍汇总,以期为推动PAT在中药制造工业中的应用提供借鉴,助推中药行业智能化转型升级及高质量发展。

关键词：过程分析技术中药制造在线检测关键质量属性近红外智能制造

中国马铃薯晚疫病菌对新型杀菌剂氰霜唑的敏感性及抑菌表型研究

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西南农业学报 2024年第4期37卷 729-737页

作者：张红雪邓登超杨明王霍超曹继芬谢勇赵志坚云南农业大学植物保护学院昆明650201 云南省农业科学院经济作物研究所昆明650205

[目的]监测中国马铃薯晚疫病菌群体对新型高效杀菌剂氰霜唑的抗药性水平,探究氰霜唑的抑菌作用,为晚疫病的绿色防控和杀菌剂合理使用提供科学依据。[方法]采用含药平板法测定2015—2020年分离自中国四大马铃薯优势区域的马铃薯晚疫病菌... 详细信息

[目的]监测中国马铃薯晚疫病菌群体对新型高效杀菌剂氰霜唑的抗药性水平,探究氰霜唑的抑菌作用,为晚疫病的绿色防控和杀菌剂合理使用提供科学依据。[方法]采用含药平板法测定2015—2020年分离自中国四大马铃薯优势区域的马铃薯晚疫病菌对氰霜唑的敏感性,计算EC_(50)、抗性倍数和抗性指数,评估我国马铃薯晚疫病菌对氰霜唑的抗药性水平。离体法测定氰霜唑对晚疫病菌不同生长发育阶段的抑制表型及其对病原菌致病性的影响。[结果]中国4个马铃薯优势区域160株晚疫病菌对氰霜唑敏感性的频率分布表现为连续单峰曲线,近似正态分布;EC_(50)值处于0.0666~3.8498μg/mL,平均EC_(50)值为(0.5286±0.5394)μg/mL;马铃薯晚疫病菌对氰霜唑较敏感,且敏感菌株在群体中的比例为89.0%,为优势群体,同时检测到低抗菌株,未检测到中抗和高抗菌株。抗药性水平表明,4个优势区域晚疫病菌对氰霜唑的平均EC_(50)值和平均抗性倍数无显著性差异,北方一作区和西南混作区的低抗菌株频率超过10%。氰霜唑对晚疫病菌菌丝生长、孢子囊产生、孢子囊萌发、游动孢子释放、休止孢萌发等生长发育阶段有显著抑制,严重削弱了其致病性。[结论]中国马铃薯晚疫病菌对氰霜唑较为敏感,4个优势区域的晚疫病菌对氰霜唑的抗性指数相近且极低,抗药性风险较低,仍是目前晚疫病绿色防控的理想药剂。氰霜唑抑制了晚疫病菌的生长发育,从而削弱了其对寄主的致病性。

关键词：马铃薯晚疫病菌氰霜唑抗药性抑菌表型

A new design approach for the established flow region of vertical,dilute-phase pneumatic conveyors

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Particuology 2022年第7期20卷 10-20页

作者： John M.Wheeldon jan Baeyens Shuo Li Yimin deng European Powder and Process Technology Longfellow DriveKetteringUnited Kingdom KU Leuven Department of Chemical EngineeringProcess and Environmental Technology LabJ.De Nayerlaan 52860 Sint-Katelijne-WaverBelgium Beijing University of Chemical Technology Beijing Advanced Centre of Smart Matter Science and EngineeringBeijingChina

An analysis has been completed for a comprehensive set of vertical,dilute-phase pneumatic conveying pressure drop data from an investigation by Flatow.The data were collected in the established flow region for eight different materials conveyed in 0.05-,0.10-,0.20-m internal diameter,20-m tall steel risers.Particle velocities derived from the pressure drop data were used to develop an equation of motion that includes terms for pipe diameter,terminal velocity,coefficient of restitution,and particle shape.The best data fit was achieved using the actual gas density and the actual gas velocity adjusted for voidage.Adjusting the terminal velocity for voidage,an approach recommended by many investigators,did not improve the fit for reasons identified by the present research.Using the equation of motion,particle velocities were predicted and used to calculate total pressure drops that are within±15%of the measured values.The calculated values also produce the characteristic trough-shaped total pressure drop curves allowing the minimum pressure drop gas velocity to be determined without recourse to a separate correlation.A comparison with other studies using shorter risers indicates that data from these studies likely include acceleration effects.A separate study will investigate this observation further.

关键词： Dilute-phase Vertical Pneumatic conveying Design equations Pressure drops

Learning-based joint UAV trajectory and power allocation optimization for secure IoT networks

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Digital Communications and Networks 2022年第4期8卷 415-421页

作者： Dan deng Xingwang Li Varun Menon Md Jalil Piran Hui Chen Mian Ahmad jan School of Information Engineering Guangzhou Panyu PolytechnicGuangzhou410630China School of Physics and Electronic Information Engineering Henan Polytechnic UniversityJiaozuo454150China Department of Computer Science and Engineering SCMS School of Engineering and TechnologyIndia Department of Computer Science and Engineering Sejong UniversitySouth Korea Department of Computer Science Abdul Wali Khan University MardanPakistan

Non-Orthogonal Multiplex Access(NOMA)can be deployed in Unmanned Aerial Vehicle(UAV)networks to improve spectrum efficiency.Due to the broadcasting feature of NOMA-UAV networks,it is essential to focus on the security of the wireless system.This paper focuses on maximizing the secrecy sum rate under the constraint of the achievable rate of the legitimate channels.To tackle the non-convexity optimization problem,a reinforcement learning-based alternative optimization algorithm is proposed.Firstly,with the help of successive convex approximations,the optimal power allocation scheme with a given UAV trajectory is obtained by using convex optimization tools.Afterwards,through plenty of explorations of the wireless environment,the Q-learning networks approach the optimal location transition strategy of the UAV,even without the wireless channel state information.

关键词： Unmanned aerial vehicle(UAV) NOMA Reinforcement learning Secure communications Deep Q-learning

体外循环心脏术后肺部感染的危险因素及其预测模型

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中华医院感染学杂志 2024年第3期34卷 390-394页

作者：彭婷婷邓殉张山首都医科大学附属北京安贞医院心脏外科危重症中心北京100029 首都医科大学护理学院北京100069

目的分析体外循环心脏术后肺部感染的危险因素及其预警模型.方法选择2021年1月-2022年12月于某三甲医院ICU完成体外循环心脏手术的172例患者展开回顾性分析,依据患者术后肺部感染情况分为感染组(n=41)和对照组(n=131);采用多因素Logisti... 详细信息

目的分析体外循环心脏术后肺部感染的危险因素及其预警模型.方法选择2021年1月-2022年12月于某三甲医院ICU完成体外循环心脏手术的172例患者展开回顾性分析,依据患者术后肺部感染情况分为感染组(n=41)和对照组(n=131);采用多因素Logistic回归分析归纳体外循环心脏术后肺部感染的危险因素,构建多因素联合应用的预警模型,总结感染组患者病原菌情况.结果糖尿病、体外循环时间、美国麻醉师协会(ASA)分级为体外循环心脏术后患者发生肺部感染的危险因素,淋巴细胞(LYM)是保护因素(P<0.05);由危险因素构建的Log(P)预警模型,对体外循环心脏术后患者发生肺部感染的预警效能较高,受试者工作特征曲线下面积(ROC-AUC)(0.95CI)为0.884(0.769~0.969);感染组患者的病原菌以革兰阴性菌(70.59%)为主,其中鲍氏不动杆菌(36.76%)为主要菌株.结论糖尿病、体外循环时间、ASA分级Ⅲ~Ⅳ级是体外循环心脏术后肺部感染的危险因素,LYM为保护因素,临床应对高危患者加强监测和预警,并及时依据感染菌株给予抗菌药物治疗,以改善患者预后.

关键词：心脏手术体外循环肺部感染预测模型病原学危险因素