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International Journal of Agricultural and Biological Engineering 2021年第6期14卷 85-92页

作者： Zhenggui li wangxu li Qifan Wang Ru Xiang Jie Cheng Wei Han Zhaoqiang Yan Key Laboratory of Fluid and Power Machinery Ministry of EducationXihua UniversityChengdu 610039China Huaneng Gansu Hydropower Development Co. LtdLanzhou 730000China School of Energy and Power Engineering Lanzhou University of TechnologyLanzhou 730050China Zigong Zhaoqiang Sealing Products Industrial Co. LtdZigong 643000SichuanChina

The fluctuation law of magnetic fluid seal interface of an agricultural centrifugal pump is theoretically unknown;the pressure and velocity fluctuations are crucial factors that cause interface *** this study,the pressure and velocity fluctuations of the sealing interface on an agricultural centrifugal pump during cavitation were investigated based on the methods of Ansys CFX numerical calculation and experimental *** results demonstrated that at the same flow rate,the pressure fluctuation amplitude of the sealing interface decreased gradually from the shaft surface to the bottom of the polar *** different flow rates,the amplitude of the pressure fluctuation decreased with an increase in the flow *** cavitation of the medium aggravated the impact and water hammer of the liquid,leading to the occurrence of the jitter phenomenon in the sealing interface to accelerate the fluctuation frequency of the axial velocity of the sealing liquid,which accelerated the emulsification of the magnetic *** law can provide a reference for the design of magnetic fluid sealing devices for agricultural centrifugal pumps.

关键词： centrifugal pump magnetic liquid sealing device medium cavitation interface fluctuations

极齿关键参数对磁流体密封热特性影响的试验研究

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润滑与密封 2021年第9期46卷 99-104页

作者：程杰李正贵李望旭龚佳成西华大学流体及动力机械教育部重点实验室四川成都610039

为探讨磁流体密封极齿参数对磁流体热特性的影响,利用传热学理论构建磁流体密封装置的传热计算模型,研究不同转速下密封间隙、极齿宽度、极齿槽宽度和极齿高度与磁流体温度的关系。在磁流体密封实验台上研究密封间隙、极齿宽度、极齿槽... 详细信息

为探讨磁流体密封极齿参数对磁流体热特性的影响,利用传热学理论构建磁流体密封装置的传热计算模型,研究不同转速下密封间隙、极齿宽度、极齿槽宽度和极齿高度与磁流体温度的关系。在磁流体密封实验台上研究密封间隙、极齿宽度、极齿槽宽度和极齿高度对磁流体温度的影响,并利用模型计算结果对试验结果进行了验证。试验结果表明:随着密封间隙和极齿高度的增加,磁流体温度逐渐减小,呈负指数变化趋势;随着极齿宽度的增加,磁流体温度线性增加;随着极齿槽宽度的增加,磁流体的温度基本不变;密封间隙对磁流体温度影响最大,其次是极齿宽度和极齿高度,极齿槽宽度对磁流体温度基本没有影响。研究表明,在一定范围内适当增加密封间隙和极齿高度,适当减小极齿宽度,可以在一定程度上减小磁流体的发热量,提高磁流体密封装置寿命。

关键词：磁流体密封极齿参数热特性

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双磁源磁性液体密封装置的压力特性实验研究

武汉大学学报（工学版） 2024年第2期57卷 254-260页

作者：程杰李正贵李望旭李新锐龚佳成西华大学流体及动力机械教育部重点实验室四川成都610039

密封结构优化设计一直是磁性液体密封的研究热点。首先设计了一种新型双磁源磁性液体密封装置,然后利用电磁学原理构建了该密封装置的磁路模型,得到了该结构的间隙、极齿宽度、极齿高度、极齿槽宽度和永磁体轴向宽度的磁路和耐压方程,... 详细信息

密封结构优化设计一直是磁性液体密封的研究热点。首先设计了一种新型双磁源磁性液体密封装置,然后利用电磁学原理构建了该密封装置的磁路模型,得到了该结构的间隙、极齿宽度、极齿高度、极齿槽宽度和永磁体轴向宽度的磁路和耐压方程,接着进行试验验证。研究结果表明:随着间隙的增加,密封压力呈递减的指数变化;随着极齿宽度和极齿槽宽度的增加,密封压力都呈开口向下的抛物线变化,分别在1.5、4.5 mm处取得极大值;随着极齿高度的增加,密封压力呈线性递减变化,但是极齿高度较小时,理论密封压力较大,极齿处存在漏磁,实际密封效果可能不佳,所以建议极齿高度不能取值太小。本装置的总压力相对于仅有轴向极齿的装置增大了约50%,密封能力显著提高。

关键词：磁性液体密封双磁源结构压力特性优化设计

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离心式铁磁流体微泵的设计及流动特性分析

哈尔滨工业大学学报 2024年第4期56卷 137-147页

作者：李望旭李正贵韩伟行怡帆谭善文司国雷陈君辉兰州理工大学能源与动力工程学院兰州730050 流体及动力机械教育部重点实验室(西华大学) 成都610039 四川航天烽火伺服控制技术有限公司成都611130

铁磁流体微泵由于其自润滑性和自密封性,使其更加符合微流控技术应用在生物医学、生命科学、化学分析、航空航天等领域的需求,而在目前的结构设计中无法同时满足加工简单、可靠性高、流动稳定等优势,因此限制其应用及发展。为提高铁磁... 详细信息

铁磁流体微泵由于其自润滑性和自密封性,使其更加符合微流控技术应用在生物医学、生命科学、化学分析、航空航天等领域的需求,而在目前的结构设计中无法同时满足加工简单、可靠性高、流动稳定等优势,因此限制其应用及发展。为提高铁磁流体微泵的可靠性和稳定性,促进其发展和应用,本研究基于铁磁流体的外场控制原理、磁流变效应及介质流体的流体力学行为设计了一种离心式的新型铁磁流体微泵,并应用数值计算分析了介质流体流动特性。结果表明:该微泵可以有效实现泵送过程,当转速为10 r/min时,一个周期内的泵送净流量可达0.07 kg/T,且在两股铁磁流体的交替作用下可以阻断泵腔进口与出口的介质流体质量交换;由于铁磁流体与泵腔结构的动静干涉作用,导致出口流量存在轻微脉动(数量级为10^(-5)),但仍处于层流状态(Re<1),并且由于惯性力与特征尺寸相关而黏滞力与特征尺寸无关等力学因素,导致泵送动力对出口尺寸长度非常敏感,在转速4 r/min、出口段长度9 mm时无法实现有效泵送。同时对铁磁流体与泵送介质流体之间的相界面压力波动和自密封性能进行分析,得到相界面上的压力波动峰值远小于铁磁流体自密封性能,相差3个数量级,从铁磁流体的密封稳定性和界面稳定性角度验证了离心式铁磁流体微泵的可行性。

关键词：铁磁流体微泵惯性驱动泵送过程重叠网格

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以李东垣原著为依据谈谈对“阴火”的认识

国医论坛 2010年第3期25卷 8-10页

作者：王旭丽福建中医学院国医堂 350003

鉴于现代学者对李东垣著作中的"阴火"所存在的诸多不同认识,以东垣著作原文为依据,从东垣的著作原文中对"阴火"的论述与治疗主旨及用药出发,阐述了"阴火"不能被简单地视为心火或者相火,"阴火"的内涵有一定复杂性,不可无视其复杂性。

关键词：李东垣阴火心火相火复杂性

变运行参数的磁性液体密封中磁液温度特性分析

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润滑与密封 2021年第9期46卷 61-67页

作者：李望旭李正贵袁久越颜招强流体及动力机械教育部重点实验室(西华大学) 四川成都610039 自贡兆强密封制品实业有限公司四川自贡643000

磁性液体工作温度高于汽化温度时不仅会导致磁性液体的表面活性物质受损,还会引起磁性液体汽化。为探讨磁性液体密封中磁液的温度特性,基于数值计算和试验验证相结合的方法,研究磁性液体旋转密封的转速、轴径和温度的关系,并分析磁性液... 详细信息

磁性液体工作温度高于汽化温度时不仅会导致磁性液体的表面活性物质受损,还会引起磁性液体汽化。为探讨磁性液体密封中磁液的温度特性,基于数值计算和试验验证相结合的方法,研究磁性液体旋转密封的转速、轴径和温度的关系,并分析磁性液体工作温度高于汽化温度时的相变过程。结果表明:磁性液体旋转密封的温度最大值出现在与轴表面相接触的位置,最小值出现在与极齿底部相接触的位置;随转速和轴径的增大,磁液温度最大值均升高,当两工况轴径与转速乘积相等时,磁性液体的温升值相同;当磁性液体温度高于其汽化温度时,与外界相通靠近轴表面附近的磁性液体最先发生相变,相变面积呈现抛物线形状向内扩散,且相同工作温度下,磁性液体的相变体积分数随轴径增大而降低。

关键词：磁性液体密封磁性液体汽化温度相变

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磁性液体性能及运行工况对密封耐压值的影响

润滑与密封 2024年第5期49卷 129-135页

作者：陈芳张杰李正贵李望旭邓波闫盛楠颜招强西华大学能源与动力工程学院四川成都610039 西华大学流体及动力机械教育部重点实验室四川成都610039 自贡兆强密封制品实业有限公司四川自贡643020

为研究不同种类磁性液体及密封工况对密封效果的影响,以Fe_(3)O_(4)为磁性颗粒,以链状氟醚油为基液,制备一系列不同颗粒含量、基液分子量的磁性液体,对磁性颗粒及磁性液体的结构、性能进行表征,在搭建的密封试验台上测试磁性液体种类及... 详细信息

为研究不同种类磁性液体及密封工况对密封效果的影响,以Fe_(3)O_(4)为磁性颗粒,以链状氟醚油为基液,制备一系列不同颗粒含量、基液分子量的磁性液体,对磁性颗粒及磁性液体的结构、性能进行表征,在搭建的密封试验台上测试磁性液体种类及运行工况对密封耐压效果的影响。结果表明:制备的磁性颗粒粒径为纳米级,呈近球形形貌,具有较高的饱和磁化强度,磁性液体具有较好的分散稳定性;随颗粒含量增加、基液分子量增大,密封耐压值先增大后减小;在颗粒质量分数为30%、基液分子量为4600 g/mol时,密封耐压值最高;随主轴转速增大,密封耐压值逐渐减小;随密封时间延长,密封耐压值先减小后趋于稳定。

关键词：磁性液体密封耐压值饱和磁化强度密封寿命分散稳定性

Interpretable Machine Learning Method for Compressive Strength Prediction and Analysis of Pure Fly Ash-based Geopolymer Concrete

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Journal of Wuhan University of Technology(Materials Science) 2025年第1期40卷 65-78页

作者： SHI Yuqiong li Jingyi ZHANG Yang li li Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas of Ministry of Education Northwest A&F Uni-versityYangling 712100China College of Water Resources and Architectural Engineering Northwest A&F UniversityYangling 712100China Chongqing Key Laboratory of Public Big Data Security Technology Chongqing 401420China Chongqing College of Mobile Communication Chongqing 401520China Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina National Rail Transit Electrification and Automation Engineering Technology Research Center(Hong Kong Branch) The Hong Kong Polytechnic UniversityKowloonHung HomHong KongChina

In order to study the characteristics of pure fly ash-based geopolymer concrete(PFGC)conveniently,we used a machine learning method that can quantify the perception of characteristics to predict its compressive *** this study,505 groups of data were collected,and a new database of compressive strength of PFGC was *** order to establish an accurate prediction model of compressive strength,five different types of machine learning networks were used for comparative *** five machine learning models all showed good compressive strength prediction performance on *** them,R2,MSE,RMSE and MAE of decision tree model(DT)are 0.99,1.58,1.25,and 0.25,*** R2,MSE,RMSE and MAE of random forest model(RF)are 0.97,5.17,2.27 and 1.38,*** two models have high prediction accuracy and outstanding generalization *** order to enhance the interpretability of model decision-making,we used importance ranking to obtain the perception of machine learning model to 13 *** 13 variables include chemical composition of fly ash(SiO_(2)/Al_(2)O_(3),Si/Al),the ratio of alkaline liquid to the binder,curing temperature,curing durations inside oven,fly ash dosage,fine aggregate dosage,coarse aggregate dosage,extra water dosage and sodium hydroxide *** temperature,specimen ages and curing durations inside oven have the greatest influence on the prediction results,indicating that curing conditions have more prominent influence on the compressive strength of PFGC than ordinary Portland cement *** importance of curing conditions of PFGC even exceeds that of the concrete mix proportion,due to the low reactivity of pure fly ash.

关键词： machine learning pure fly ash geopolymer compressive strength feature perception

Photo‑Energized MoS_(2)/CNT Cathode for High‑Performance li–CO_(2)Batteries in a Wide‑Temperature Range

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Nano-Micro Letters 2025年第1期17卷 160-175页

作者： Tingsong Hu Wenyi lian Kang Hu Qiuju li Xueliang Cui Tengyu Yao Laifa Shen Jiangsu Key Laboratory of Materials and Technologies for Energy Storage College of Materials Science and TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016People’s Republic of China

li–CO_(2) batteries are considered promising energy storage systems in extreme environments such as Mars;however,severe performance degradation will occur at a subzero temperature owning to the sluggish reaction ***,a photo-energized strategy adopting sustainable solar energy in wide working temperature range li–CO_(2) battery was achieved with a binder-free MoS_(2)/carbon nanotube(CNT)photo-electrode as *** unique layered structure and excellent photoelectric properties of MoS_(2) facilitate the abundant generation and rapid transfer of photo-excited carriers,which accelerate the CO_(2) reduction and li_(2)CO_(3) decomposition upon *** illuminated battery at room temperature exhibited high discharge voltage of 2.95 V and mitigated charge voltage of 3.27 V,attaining superior energy efficiency of 90.2%and excellent cycling stability of over 120 *** at an extremely low temperature of−30℃,the battery with same electrolyte can still deliver a small polarization of 0.45 V by the photoelectric and photothermal synergistic mechanism of MoS_(2)/CNT *** work demonstrates the promising potential of the photo-energized wide working temperature range li–CO_(2) battery in addressing the obstacle of charge overpotential and energy efficiency.

关键词： li-CO_(2)batteries Photo-energized Wide operation-temperature Kinetics MoS_(2)

Constraints on holographic QCD phase transitions from PTA observations

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 71-78页

作者： Song He li li Sai Wang Shao-Jiang Wang Center for Theoretical Physics and College of Physics Jilin University School of Physical Science and Technology Ningbo University Max Planck Institute for Gravitational Physics (Albert Einstein Institute) CAS Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of Sciences (UCAS) School of Physical Sciences University of Chinese Academy of Sciences (UCAS) Theoretical Physics Division Institute of High Energy Physics Chinese Academy of Sciences

The underlying physics of QCD phase transition in the early Universe remains largely unknown due to its strong-coupling nature during the quark-gluon plasma/hadron gas transition, yet a holographic model has been proposed to quantitatively fit the lattice QCD data while with its duration of the first-order phase transition(FoPT) left undetermined. At specific baryon chemical potential, the first-order QCD phase transition agrees with the observational constraint of baryon asymmetry. It, therefore, provides a scenario for phase transition gravitational waves(GWs) within the standard model of particle physics. If these background GWs could contribute dominantly to the recently claimed common-spectrum red noise from pulsar timing array(PTA) observations, the duration of this FoPT can be well constrained, and the associated primordial black holes are still allowed by current observations.

关键词： pulsar timing array QCD phase transition gravitational waves primordial black holes