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超声波对热浸镀锌的影响

腐蚀科学与防护技术 2000年第1期12卷 32-35页

作者：李英龙李宝绵刘永涛戴恩泰东北大学黄金学院沈阳110015

研究了超声波介入对热浸镀锌的镀层组织和性能的影响．结果表明大功率超声使镀层中不出现脆性的ＦｅＺｎ金属间化合物层，镀层组织致密表面光滑，可显著地提高镀层的粘附性、变形性和耐蚀性．

关键词：超声波热浸镀锌

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低合金钢FQK400的连续冷却转变

热加工工艺 2009年第10期38卷 45-48页

作者：刘秉余于景媛李宝绵崔建忠辽宁工业大学材料与化学工程学院辽宁锦州121001 东北大学材料电磁过程研究教育部重点实验室辽宁沈阳110004

采用Gleeble-2000热模拟试验机研究了FQK400钢的连续冷却转变过程,分析了不同冷速下钢的组织转变和力学性能,研究了形变对连续冷却条件下相变的影响规律。结果表明,FQK400钢的临界点Ac1、Ac3分别为730℃和840℃。除30～40℃/s冷速范围... 详细信息

采用Gleeble-2000热模拟试验机研究了FQK400钢的连续冷却转变过程,分析了不同冷速下钢的组织转变和力学性能,研究了形变对连续冷却条件下相变的影响规律。结果表明,FQK400钢的临界点Ac1、Ac3分别为730℃和840℃。除30～40℃/s冷速范围内同时有10%的上贝氏体,5℃/s冷速下同时有10%的魏氏组织外,其他冷速下贝氏体均为粒状贝氏体,铁素体均为多边形铁素体和针状铁素体。900℃变形50%,使先共析铁素体转变线左上移,依冷速不同,铁素体转变量增加5%～13%,珠光体转变量减少5%～8%,贝氏体转变开始线下降约10℃,转变终了线基本不变,贝氏体转变量减少5%～25%,并使不发生贝氏体转变的临界冷速由0.8℃/s降低到0.3℃/s,马氏体转变量在冷速30～15℃/s时增加了10%～15%,其他冷速时减少3%～7%。变形后的相含量-冷速变化规律基本不变。

关键词：低合金钢 Nb 连续冷却转变曲线临界点

复杂锡镍黄铜合金加工硬化及再结晶温度的研究

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材料与冶金学报 2018年第4期17卷 311-316页

作者：付博闻刘峰廖骏骏李宝绵丁桦东北大学材料科学与工程学院沈阳110819 宁波兴业盛泰集团有限公司省级企业技术中心浙江宁波315336 东北大学材料电磁过程研究教育部重点实验室沈阳110819

对Cu-Zn-Sn-Ni合金进行了不同变形量的冷变形,绘制出了合金的加工硬化曲线.对退火后不同变形量试样的抗拉强度、硬度、延伸率及导电率进行测试和组织观察,确定了合金在不同变形量时的再结晶温度.结果表明,合金经冷加工变形后,具有明显... 详细信息

对Cu-Zn-Sn-Ni合金进行了不同变形量的冷变形,绘制出了合金的加工硬化曲线.对退火后不同变形量试样的抗拉强度、硬度、延伸率及导电率进行测试和组织观察,确定了合金在不同变形量时的再结晶温度.结果表明,合金经冷加工变形后,具有明显的加工硬化效果,在80%变形量下,其强度可达590 MPa,延伸率为5. 6%,导电率为28. 2%IACS.合金的强度、硬度随变形量的增大,呈先增大后趋于稳定的趋势.而延伸率、导电率与变形量则呈相反的变化规律.此外,冷变形程度越大,合金的再结晶温度越低.

关键词： Cu-Zn-Sn-Ni合金加工硬化再结晶温度抗拉强度

基于回归分析结果创建PRECEDE-PROCEED护理模式对妊娠高血压患者的应用效果

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河南医学研究 2024年第5期33卷 937-940页

作者：李宝勉陈淑梅张莹郑州大学附属郑州中心医院产科一病区河南郑州450000

目的探讨基于回归分析结果创建PRECEDE-PROCEED护理模式对妊娠高血压患者的应用效果。方法选取2020—2023年在郑州大学附属郑州中心医院产科就诊的200例妊娠高血压患者,随机分为对照组和研究组,每组100例。对照组接受常规护理,研究组在... 详细信息

目的探讨基于回归分析结果创建PRECEDE-PROCEED护理模式对妊娠高血压患者的应用效果。方法选取2020—2023年在郑州大学附属郑州中心医院产科就诊的200例妊娠高血压患者,随机分为对照组和研究组,每组100例。对照组接受常规护理,研究组在常规护理的基础上,根据回归分析结果创建PRECEDE-PROCEED护理模式,进行个体化、系统化、持续化的健康教育和干预。比较两组患者的血压控制情况、并发症发生率、满意度。结果研究组患者的收缩压、舒张压、平均动脉压均低于对照组(P<0.05)。研究组患者的子痫前期、子痫、胎盘早剥等并发症的发生率低于对照组(P<0.05)。研究组患者的护理满意度高于对照组(P<0.05)。结论基于回归分析结果创建PRECEDE-PROCEED护理模式能够有效降低妊娠高血压患者的血压水平,减少并发症的发生,提高患者的满意度,是一种值得推广的护理方法。

关键词：妊娠高血压回归分析 PRECEDE-PROCEED模式护理效果

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铝-空气电池阳极材料及其电解液的研究进展

材料导报 2019年第1期33卷 135-142页

作者：吴子彬宋森森董安杨宗武李雪科秦克张海涛班春燕李宝绵崔建忠 Hiromi Nagaumi 东北大学材料电磁过程研究教育部重点实验室(EMP) 沈阳110006 苏州大学沙钢钢铁学院苏州215100

金属-空气电池自进入人们的视野以来,由于其高能量密度和容量、平稳的放电特性、对负载和温度的依赖性低和较低的制造成本等特点,受到越来越多的关注。其中,锂-空气电池因具有极大的应用潜力而引起了学者们极大的研究兴趣;然而,锂-空气... 详细信息

金属-空气电池自进入人们的视野以来,由于其高能量密度和容量、平稳的放电特性、对负载和温度的依赖性低和较低的制造成本等特点,受到越来越多的关注。其中,锂-空气电池因具有极大的应用潜力而引起了学者们极大的研究兴趣;然而,锂-空气电池对周围环境十分敏感,容易造成爆炸,存在安全隐患;此外,锂离子电池的大规模生产和应用造成了原材料锂价格的大幅上涨。为了实现电池的商业化应用,选用来源广泛、经济实惠的电极材料成为必不可少的条件。铝是地壳中含量最多的金属元素,具有矿藏丰富、质量轻、无污染、安全、价格低廉和回收利用率高等优点,是一种潜在的储能材料。铝的理论质量比容量为2 980 mAh·g^(-1),仅次于锂(3 860 mAh·g^(-1)),其体积比容量(8.04 Ah·cm-3)约是锂的四倍(2.05 Ah·cm-3),被认为是金属-空气电池最有吸引力的候选阳极材料,也是化石燃料最有吸引力的替代者之一。然而,铝在空气和水溶液中表面上自发形成的钝化膜会显著降低铝阳极材料的活性;在碱性溶液中,铝-空气电池存在的主要问题是铝阳极材料自腐蚀导致氢析出速率较高,库伦效率降低和含水电解液的流动性可能导致的多孔空气阴极中毛细管的渗透及泄漏。因此,近年来,学者们不断开展深入研究,探索出以下几种改善铝阳极的方法:通过向铝中添加合金元素Ga、In、Sn、Zn、Mg、Bi、Mn等来改变铝阳极材料的活性和减少析氢反应;对电解液添加剂进行研究,发现部分植物提取液作为电解液添加剂可以保持铝阳极活性,降低析氢腐蚀;开发离子液体、固态和凝胶电解液,一方面可以减小铝阳极自腐蚀,提高阳极利用率,另一方面可减小铝-空气电池体积,增加电池的灵活性。目前研究获得性能较好的碱性铝-空气电池的阳极材料有Al-Ga/In-Mg系列、Al-Ga/In-Mg-Sn系列、Al-Ga-In-Bi-Pb系列等合金,其中部分铝阳极合金已经实现了实际应用。近几年研究工作获得了羽扇豆提取物、茄属植物叶的提取物等绿色电解液添加剂,其可以保持铝阳极的电化学活性,降低腐蚀率。此外,研究发现,室温下低聚氟化氢离子液体作为电解液可以活化铝阳极,降低其腐蚀速率,一些便携式铝-空气电池采用固态或凝胶电解液已经在护理医疗设备、商用LED手表方面应用。本文主要从铝阳极材料、电解质和电解质添加剂三方面论述了其对铝-空气电池性能的影响,并简单阐述了铝-空气电池放电的基本原理、面临的挑战和最新研究进展及应用。首先,综述了铝与合金元素的合金化,以此减少铝的自腐蚀,提高电池性能;并介绍了通过一定的加工工艺来改善铝阳极电化学性能的方法。其次,探讨了水溶剂电解质和非水溶剂电解质在铝-空气电池中的应用。同时,也研究了电解质添加剂对铝-空气电池的电化学性能的影响。最后,进一步明确了空气电池未来的研究和发展方向。

关键词：铝-空气电池铝阳极材料电解质电解质添加剂电化学性能

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

Manufacture the conducting polymer with light

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Science China Chemistry 2025年第1期68卷 8-9页

作者： Yang li Tianyu li Yan Ji Baoguang liu College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology) Nanjing University of Posts & Telecommunications

Poly(3,4-ethylenedioxythiophene) (PEDOT), heralded as the “king” of conducting polymers, is esteemed in bioelectronics for its mixed electronic and ionic conductivity, mechanical properties compatible with biological tissues, tunable healing ability and stability in diverse environments [1]. Based on additive manufacturing of three-dimensional structures,PEDOT realizes the implementation in the efficient production of flexible bioelectronics, the construction of intricate electrode-neural implantations, and the development of smart brain-computer-interfaces [2].

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A Wind Tunnel Experimental Study on the Wake Characteristics of a Horizontal Axis Wind Turbine

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Journal of Thermal Science 2025年第1期34卷 145-158页

作者： GUO Xingduo li Yinran li Rennian MA Yulong WEI Kui College of Energy and Power Engineering Lanzhou University of Technology Key Laboratory of Fluid Machinery and Systems Gansu Provincial Technology Centre for Wind Turbines

The characteristics of wind turbine wakes are influenced by multiple factors,including the atmospheric boundary layer(ABL) wind and wind turbine operating conditions(e.g.,tip speed ratio and yaw angle).In this study,two types of ABL winds with different velocity gradients and turbulence intensities are generated in a wind tunnel through configurations of spires,baffles,and various numbers of roughness elements.A wind turbine with a rotor diameter of 0.8 m and a hub height of 0.6 m is tested under varying tip speed ratios,yaw angles,and ABL wind *** results indicate that the streamwise velocity deficit in the near-wake region becomes more pronounced with an increase in the tip speed ratio,while the far-wake velocity deficit remains largely unaffected by changes in the tip speed *** the yaw angle increases,the wake deflection becomes more prominent and the wake narrows;the offset of the wake center at various downstream positions grows linearly,reaching a maximum value of approximately half the rotor ***,the turbulence level and influence range in the wake region are reduced when the turbine is *** ABL wind conditions,high turbulence intensity in the incoming flow accelerates wake recovery,and the Reynolds stress at different lateral positions tends to become consistent with increasing longitudinal ***,turbulence has a significant impact on the meandering characteristics of the wind turbine wake,with greater fluctuations in the wake center observed under higher turbulence ***,this study provides insights that could inform the optimal operation of wind farms.

关键词： horizontal axis wind turbine turbulence wind tunnel experiment wind turbine wake

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