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Journal of Magnesium and Alloys 2024年第1期12卷 251-266页

作者： Fei-er Shangguan wei-li cheng Yu-hang Chen Ze-qin Cui Hui Yu Hong-xia Wang li-fei Wang Hang li Hua Hou School of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China School of Materials Science and Engineering Hebei University of TechnologyTianjin 300132China School of Materials Science and Engineering North University of ChinaTaiyuan 030051China

The influence of micro-Ca/In alloying on the microstructural charac teristics,electrochemical behaviors and discharge properties of extruded dilute Mg-0.5Bi-0.5Sn-based(wt.%)alloys as anodes for Mg-air batteries are *** grain size and texture intensity of the Mg-Bi-Sn-based alloys are significantly decreased after the Ca/In alloying,particularly for the In-containing *** that,in addition to nanoscale Mg_(3)Bi_(2)phase,a new microscale Mg_(2)Bi_(2)Ca phase forms in the Ca-containing *** electrochemical test results demonstrate that Ca/In micro-alloying can enhance the electrochemical *** In to alloy the Mg-Bi-Sn-based alloy is effective in restricting the cathodic hydrogen evolution(CHE)kinetics,leading to a low self-corrosion rate,while severe CHE occurred after Ca *** micro-alloying of Ca/In to Mg-Bi-Sn-based alloy strongly deteriorates the compactness of discharge products film and mitigates the"chunk effect"(CE),hence the cell voltage,anodic efficiency as well as discharge capacity are greatly *** In-containing alloy exhibits outstanding discharge performance under the combined effect of the modified microstructure and discharge products,thus making it a potential anode material for primary Mg-air battery.

关键词： Mg-air batteries Mg-Bi-Sn based alloys Electrochemical behaviors Discharge properties

熔体过热和脉冲磁场协同处理对Mn_(5)Si_(3)增强Cu-35Zn-3Al合金显微组织、力学和耐磨性能的影响

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Transactions of Nonferrous Metals Society of China 2024年第3期34卷 918-934页

作者：李航牛冬涛张忠涛杨帆王红霞程伟丽太原理工大学材料科学与工程学院太原030024 金龙精密铜管有限公司重庆404100

研究熔体过热和脉冲磁场协同处理对Mn_(5)Si_(3)增强Cu-35Zn-3Al合金显微组织、力学和耐磨性能的影响。研究结果表明,协同处理促进了熔体中的溶质迁移以及Mn_(5)Si_(3)晶体生长的吸附动力学,抑制了六棱柱形貌Mn_(5)Si_(3)颗粒上孔洞的... 详细信息

研究熔体过热和脉冲磁场协同处理对Mn_(5)Si_(3)增强Cu-35Zn-3Al合金显微组织、力学和耐磨性能的影响。研究结果表明,协同处理促进了熔体中的溶质迁移以及Mn_(5)Si_(3)晶体生长的吸附动力学,抑制了六棱柱形貌Mn_(5)Si_(3)颗粒上孔洞的形成。协同处理后热锻态合金的抗拉强度和伸长率分别提高了9.0%和66.5%,这是由于拉伸变形过程中不含孔洞的Mn_(5)Si_(3)颗粒断裂强度提高,产生的应力集中减小,因此失效方式由脆性解理断裂转变为从基体中拔出,颗粒和基体间的载荷传递作用增强。在承受摩擦时,协同处理后合金的磨损亚表层中Mn_(5)Si_(3)颗粒不易发生剪切断裂,抑制了裂纹扩展和材料剥落,因而产生的剥层磨损减小,合金耐磨性显著提高。

关键词：复杂黄铜 Mn_(5)Si_(3)相脉冲磁场强化机理耐磨性

数字化助推中国式教育现代化的核心要义及实践策略

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教学与管理 2024年第21期 27-31页

作者：宋述光姜付高李承伟曲阜师范大学教育学院山东曲阜273165 中国石油大学(华东)体育教学部山东青岛266580 曲阜师范大学体育学部山东曲阜273165

随着技术革命快速发展,数字化业已成为助推中国式教育现代化的重要手段。重塑现代教育的关系及要素,将对教育治理、教育功能、教育理念、教育形式等产生直接影响,形成全新的教育生态。然而,数字技术快速发展,也为中国式教育现代化带来... 详细信息

随着技术革命快速发展,数字化业已成为助推中国式教育现代化的重要手段。重塑现代教育的关系及要素,将对教育治理、教育功能、教育理念、教育形式等产生直接影响,形成全新的教育生态。然而,数字技术快速发展,也为中国式教育现代化带来潜在风险,教育体系过度数字化导致学生发展异化,影响学生社交、思维等全面发展,且存在隐私泄露风险。同时,数字鸿沟及教师数字素养的差异进一步加剧教育不公平,因此,享受数字技术为教育体系带来便利与高效的同时,需重新审视现代教育与数字逻辑的抵牾及对峙,打造中国式教育现代化新范式、规范数字教育制度、平衡数字教育资源、提升教师数字素养成为数字化背景下教育现代化发展的中国方案。

关键词：教育数字化教育强国中国式教育现代化教育高质量发展

野生动物司法保护路径重构——以青海省实践为例

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哈尔滨学院学报 2024年第8期45卷 66-70页

作者：赵文成李伟成青海民族大学青海西宁810007

野生动物资源的保护与利用在维持生态系统平衡、推进绿色发展、促进人与自然和谐相处等方面起着至关重要的作用。青藏高原因其特有的地理和资源优势使得珍稀物种得到庇护,尽管曾面临人类活动对栖息地的破坏以及猎捕压力等诸多问题,但是... 详细信息

野生动物资源的保护与利用在维持生态系统平衡、推进绿色发展、促进人与自然和谐相处等方面起着至关重要的作用。青藏高原因其特有的地理和资源优势使得珍稀物种得到庇护,尽管曾面临人类活动对栖息地的破坏以及猎捕压力等诸多问题,但是青藏高原物种仍表现出极强的生存能力,是野生动物资源保护与利用的典范。青海省野生动物保护目前还存在立法不健全、范围有局限、执法效果不理想、公民保护意识不足、救助机制不完善等问题,亟待根据新修订的《野生动物保护法》,通过转变保护理念、建设国家公园主题的自然保护地、加强普法宣传和完善相关补偿制度等路径进行完善。

关键词：《野生动物保护法》青藏高原司法保护生物多样性

秸秆还田和水旱轮作模式对稻季土壤温室气体排放的影响

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植物营养与肥料学报 2024年第2期30卷 268-278页

作者：邓姣李心雨朱杰杨伟李成伟蒋梦蝶朱波聂江文刘章勇长江大学农学院主要粮食作物产业化湖北省协同创新中心湖北荆州434200 湖北省襄阳市农业科学院湖北襄阳441100

【目的】探究不同水旱轮作模式下,冬季作物秸秆还田对后茬水稻季作物产量和温室气体排放的影响,为长江中游稻田选择适宜的秸秆还田方式和农业可持续生产提供科学依据。【方法】田间试验在湖北荆州进行,设置水稻–小麦(稻麦)、水稻–油菜... 详细信息

【目的】探究不同水旱轮作模式下,冬季作物秸秆还田对后茬水稻季作物产量和温室气体排放的影响,为长江中游稻田选择适宜的秸秆还田方式和农业可持续生产提供科学依据。【方法】田间试验在湖北荆州进行,设置水稻–小麦(稻麦)、水稻–油菜(稻油)和水稻–紫云英(稻肥)3种水旱轮作模式,每个模式下设置冬季作物收获后秸秆还田和不还田处理。在秸秆还田后的水稻季,采用静态暗箱—气相色谱法连续监测稻田中甲烷(CH_(4))和氧化亚氮(N_(2)O)排放量,在水稻分蘖期、抽穗期、成熟期采集0—5、5—10、10—20 cm土层样品,测定微生物量碳(MBC)、可溶性有机碳(DOC)、铵态氮(NH_(4)^(+)-N)和硝态氮(NO_(3)^(-)-N)含量,收获期测定水稻产量。【结果】秸秆还田和不同轮作模式对后茬水稻产量均无显著影响。与稻肥轮作相比,在秸秆还田条件下稻油和稻麦轮作水稻季土壤CH_(4)和N_(2)O排放分别高出44%~58%和17%~30%,在秸秆不还田条件下则分别高出58%~72%和15%~22%。与秸秆不还田相比,秸秆还田条件下3种轮作模式平均CH_(4)和N_(2)O排放分别增加26%~39%和20%~29%。秸秆还田条件下,稻油和稻麦轮作稻季土壤全球增温潜势(GWP)和温室气体排放强度(GHGI)分别比稻肥轮作高出14%~19%和12%~19%,秸秆不还田条件下分别高出18%~23%和15%~24%。与秸秆不还田相比,秸秆还田条件下3种轮作模式稻季土壤平均GWP和GHGI高出31%和32%,同时土壤硝态氮、微生物量碳和可溶性有机碳含量均显著提高。此外,稻麦轮作土壤微生物量碳和可溶性有机碳含量显著高于稻肥、稻油轮作。相关性分析表明,秸秆还田条件下,CH_(4)和N_(2)O排放与NO_(3)^(-)-N呈极显著正相关(P<0.01),而秸秆不还田条件下CH_(4)排放与NO_(3)^(-)-N呈极显著正相关(P<0.01),N_(2)O排放与NH_(4)^(+)-N呈极显著正相关(P<0.01)。【结论】水稻季土壤CH_(4)和N_(2)O的排放与土壤可利用性碳氮浓度的升高密切相关。前茬作物秸秆还田导致水稻季温室气体排放显著增加,与稻麦、稻油轮作相比,水稻–紫云英轮作稻季土壤的温室气体排放量最低,是较为生态环境友好型的种植制度。

关键词：轮作模式秸秆还田增温潜势排放强度土壤可溶性有机碳微生物量碳有效氮

Numerical Simulation of Clocking Effect on Blade Unsteady Aerodynamic Force in Axial Turbine

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Journal of Thermal Science 2012年第5期21卷 474-482页

作者： li wei ZHU Xiao-cheng OUYANG Hua DU Zhao-hui Shanghai JiaoTong University Shanghai 200240 China

To give an insight into the clocking effect and its influence on the wake transportation and its interaction, the unsteady three-dimensional flow through a 1.5-stage axial low pressure turbine is simulated numerically by using a density-correction based, Reynolds-Averaged Navier-Stokes equations commercial CFD code. The 2nd stator clocking is applied over ten equal tangential positions. The results show that the harmonic blade number ratio is an important factor affecting the clocking effect. The clocking effect has very small influence on the turbine efficiency in this investigation. The difference between the maximum and minimum efficiency is about 0.1%. The maximum efficiency can be achieved when the 1st stator wake enters the 2nd stator passage near blade suction surface and its adjacent wake passes through the 2nd stator passage close to blade pressure surface. The minimum efficiency appears if the 1st stator wake impinges upon the leading edge of the 2nd stator and its adjacent wake of the 1st stator passes through the mid-channel in the 2nd stator. The wake convective transportation and the blade circulation variation due to its impingement on the subsequent blade are the main mechanism affecting the pressure variation in blade surface.

关键词： Axial Turbine Clocking Effect Numerical Simulation

Dynamic probabilistic design technique for multi-component system with multi-failure modes

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Journal of Central South University 2018年第11期25卷 2688-2700页

作者： ZHANG Chun-yi LU cheng FEI cheng-wei JING Hui-zhe li cheng-wei School of Mechanical and Power Engineering Harbin University of Science and TechnologyHarbin 150080China School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Department of Aeronautics and Astronautics Fudan UniversityShanghai 200433China

For unacceptable computational efficiency and accuracy on the probabilistic analysis of multi-component system with multi-failure modes,this paper proposed multi-extremum response surface method(MERSM).MERSM model was established based on quadratic polynomial function by taking extremum response surface model as the sub-model of multi-response surface *** dynamic probabilistic analysis of an aeroengine turbine blisk with two components,and their reliability of deformation and stress failures was obtained,based on thermal-structural coupling technique,by considering the nonlinearity of material parameters and the transients of gas flow,gas temperature and rotational *** results show that the comprehensive reliability of structure is 0.9904 when the allowable deformations and stresses of blade and disk are 4.78×10–3 m and 1.41×109 Pa,and 1.64×10–3 m and 1.04×109 Pa,***,gas temperature and rotating speed severely influence the comprehensive reliability of *** the comparison of methods,it is shown that the MERSM holds higher computational precision and speed in the probabilistic analysis of turbine blisk,and MERSM computational precision satisfies the requirement of engineering *** efforts of this study address the difficulties on transients and multiple models coupling for the dynamic probabilistic analysis of multi-component system with multi-failure modes.

关键词： probabilistic analysis multi-extremum response surface method multi-component multi-failure modes

Microstructure evolution and mechanical properties of Mg-9Al-1Si-1SiC composites processed by multi-pass equal-channel angular pressing at various temperatures

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International Journal of Minerals,Metallurgy and Materials 2021年第12期28卷 1966-1975页

作者： Xiang-peng Zhang Hong-xia Wang li-ping Bian Shao-xiong Zhang Yong-peng Zhuang wei-li cheng wei liang Shanxi Key Laboratory of Advanced Magnesium based Materials College of Materials Science and EngineeringTaiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of EducationTaiyuan University of TechnologyTaiyuan 030024China

In this study,Mg-9 Al-1 Si-1 SiC(wt%)composites were processed by multi-pass equal-channel angular pressing(ECAP)at various temperatures,and their microstructure evolution and strengthening mechanism were *** showed that the as-cast microstructure was composed of anα-Mg matrix,discontinuous Mg17Al12 phase,and Chinese script-shaped Mg2Si *** solution treatment,almost all of the Mg17Al12 phases were dissolved into the matrix,whereas the Mg2Si phases were *** subsequent multi-pass ECAP at different temperatures promoted the dynamic recrystallization and uniform distribution of the Mg17Al12 precipitates when compared with the multipass ECAP at a constant temperature.A large number of precipitates can effectively improve the nucleation ratio of recrystallization through a particle-stimulated nucleation *** addition,the SiC nanoparticles were mainly distributed at grain boundaries,which effectively prevented dislocation *** excellent comprehensive mechanical properties can be attributed to grain boundary strengthening and Orowan strengthening.

关键词： strengthening recrystallization microstructure

Unveiling the twinning and dynamic recrystallization behavior and the resultant texture evolution in the extruded Mg-Bi binary alloys during hot compression

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Journal of Materials Science & Technology 2022年第10期105卷 274-285页

作者： Yu-qin Zhang wei-li cheng Hui Yu Hong-xia Wang Xiao-feng Niu li-fei Wang Hang li School of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of Education Taiyuan University of TechnologyTaiyuan 030024China School of Materials Science and Engineering Hebei University of TechnologyTianjin 300132China

The twinning behavior, dynamic recrystallization(DRX) mechanism and the resultant texture evolution of the extruded Mg-xBi(x=0.5 wt.%, 2.0 wt.%) alloys were systematically investigated during hot compression at the strain rate of 10 s^(-1) and temperature of 200℃. The results indicate that the types and intensities of the texture are greatly dependent on the twining behavior and DRX mechanism. At the initial stage, the evolution of texture is mainly domination by the formation and variation of {1012} extension twins, which is benefcial to the compression direction(CD)-tilted basal texture. With an increase in the strain, the texture evolution is more greatly regulated by the DRX mechanism. Besides, the pyramidal slip and basal slip are activated during the compression process, resulting in the Schmid factors(SF) of pyramidal slip remain at ~0.4 and the average SFs for basal slip increase from 0.2 to0.34 as the strain increase. These fndings provide a new insight into controlling the texture of wrought Mg-Bi-based alloys during hot deformation processing.

关键词： Wrought Mg-Bi alloys Hot deformation Twinning Dynamic recrystallization Dislocation slip Texture

Microstructural evolution in electroformed nickel shaped-charge liners with nano-sized grains undergone deformation at ultrahigh strain rate

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International Journal of Minerals,Metallurgy and Materials 2010年第5期17卷 617-623页

作者： Feng Yang Chun-hua li Sheng-wei cheng Lei Wang Wen-huai Tian School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

Nickel shaped-charge liners with nano-sized grains were prepared by the electroforming technique, and the deformation at ultrahigh strain rate was performed by explosive detonation. The as-formed and post-deformed microstructures of electroformed nickel shaped-charge liners with nano-sized grains were observed by means of transmission electron microscopy, and the orientation distribution of the grains was analyzed by the electron backscattering pattern （EBSP） technique. The melting phenomenon in the jet fragment and the recovery and recrystallization in the slug after plastic deformation at ultrahigh-strain rate were observed in the ultrafine-grained nickel shaped-charge liners. The research evidence shows that dynamic recovery and recrystallization play an important role in plastic deformation at ultrahigh strain rate.

关键词： electroformed nickel nanosized plastic deformation electroformation microtexture dynamic recovery and recrystallization