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Enhancement of low-temperature toughness of Fe-Mn-C-Al alloy by rare earth Ce-modified inclusions

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Journal of Iron and Steel Research International 2024年第1期31卷 157-173页

作者： Guang-kai Yang chang-ling Zhuang Yi-zhuang li Chen Hu Shao-bo li College of Materials and Metallurgy Guizhou UniversityGuiyang550025GuizhouChina Department of Mechanical Engineering University of Hong KongHong Kong999077China The State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819LiaoningChina State Key Laboratory of Public Big Data Guizhou UniversityGuiyang550025GuizhouChina

Fe-Mn-C-Al alloys have been recognized as promising materials for certain low-temperature applications due to their exceptional mechanical properties and ***,their limited low-temperature toughness restricts their large-scale applications in specific *** influence of trace amounts of rare earth cerium(Ce)on the low-temperature toughness of Fe-18Mn-0.6C-1.8Al alloys was *** addition of Ce effectively alters the inclu-sions in the alloy,transforming large-sized irregular inclusions into fine ellipsoidal rare earth *** leads to a significant reduction in both the proportion and average size of the inclusions,resulting in their effective dispersion throughout the matrix and improved cryogenic *** presence of Ce-containing inclusions within the matrix reduces stress concentration,thereby inhibiting microcrack formation and improving impact absorption ***-cally,the addition of rare earth Ce alters the fracture behavior of the material at room temperature and low temperature,changing from brittle cleavage fracture to a more ductile failure *** impact toughness of the Fe-Mn-C-Al alloy is significantly improved by the addition of 0.0048 wt.%Ce,particularly at-196℃where the impact toughness reaches 103.6 J/cm^(2),representing an impressive improvement of 87.3%.

关键词： Fe-Mn-C-Al alloy Rare earth Low-temperature toughness Inclusion Fracture

Enhanced mechanical property by introducing bimodal grains structures in Cu-Ta alloys fabricated by mechanical alloying

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Journal of Materials Science & Technology 2024年第5期172卷 104-112页

作者： Ningyu li Yongqin chang Mingyang li Yuxiang Chen Xinrui Luo Shichao Pei Fan Yang School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Xi’an Rare Metal Materials Institute Co.Ltd Xi’an 710016China

Dispersion-strengthened copper alloys can achieve ultra-high strength,but usually at the expense of *** this study,a strategy for overcoming strength-ductility tradeoffof Cu alloys is realized through the introduction of bimodal grains ***-Ta alloys with only 0.5 at.%Ta content were successfully prepared by mechanical alloying combined with spark plasm *** samples prepared by one-step and two-step ball milling methods are named as Cu-Ta(Ⅰ)and Cu-Ta(Ⅱ),*** microstructural characterizations revealed that ultra-fine equiaxed grains with uniformly dispersed Ta precipitates were obtained in the Cu-Ta *** strength of 377 MPa for yield strength together with elongation of∼8%was obtained in Cu-Ta(Ⅰ).Bimodal grains structures composed of fine-grain zones and coarse-grain zones were successfully introduced into Cu-Ta(Ⅱ)by a two-step ball milling approach,and both yield strength(463 MPa)and elongation(∼15%)were significantly synergistic *** hardness values of both Cu-Ta(Ⅰ)and Cu-Ta(Ⅱ)were almost kept nearly constant with the increase of annealing time,and the softening temperatures of Cu-Ta(Ⅰ)and Cu-Ta(Ⅱ)are 1018 and 1013℃,reaching 93.9%and 93.5%T m of pure Cu(1083℃),*** reveals that the Cu-0.5 at.%Ta alloys exhibit excellent thermal stability and exceptional softening *** nanoclusters with semi-coherent structures play an essential role in enhancing the strength and microstructural stability of *** structures are beneficial to the activation of back stress strengthening and the initiation and propagation of microcracks,thus obtaining the extraordinary combination of strength and *** study provides a new way to fabricate dispersion-strengthened Cu alloys with high strength,high elongation,excellent thermal stability and softening resistance,which have potential application value in the field of the future fusion reactor.

关键词： Cu-Ta alloy Mechanical alloying Ta precipitates Bimodal structures Mechanical property

Robust Correlation Clustering Problem with Locally Bounded Disagreements

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Tsinghua Science and Technology 2024年第1期29卷 66-75页

作者： Sai ji Min li Mei liang Zhenning Zhang Institute of Mathematics Hebei University of TechnologyTianjin 300401China School of Mathematics and Statistics Shandong Normal UniversityJinan 250358China College of Statistics and Data Science Beijing University of TechnologyBeijing 100124China Department of Operations Research and Information Engineering Beijing University of TechnologyBeijing 100124China

Min-max disagreements are an important generalization of the correlation clustering problem(CorCP).It can be defined as *** a marked complete graph G=(V,E),each edge in the graph is marked by a positive label"+"or a negative label"_"based on the similarity of the connected *** goal is to find a clustering C of vertices V,so as to minimize the number of disagreements at the vertex with the most ***,the disagreements are the positive cut edges and the negative non-cut edges produced by clustering *** paper considers two robust min-max disagreements:min-max disagreements with outliers and min-max disagreements with *** parameter δ∈(0,1/14),we first provide a threshold-based iterative clustering algorithm based on LP-rounding technique,which is a(1/δ,7/(1-14δ))-bi-criteria approximation algorithm for both the min-max disagreements with outliers and the min-max disagreements with outliers on one-sided complete bipartite ***,we verify that the above algorithm can achieve an approximation ratio of 21 for min-max disagreements with penalties when we set parameter δ=1/21.

关键词： min-max disagreements outliers penalties approximation algorithm LP-rounding

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教学应该回归怎样的生活世界

中国教育学刊 2005年第10期 39-41页

作者：李长吉秦平哈尔滨师范大学黑龙江哈尔滨150080 哈尔滨学院黑龙江哈尔滨150086

教学所要回归的生活世界不单纯是现实的生活世界,还包括精神层面的生活世界、动态更新的生活世界、未来的生活世界和学生内心的生活世界。在回归生活世界的教学实践中,要超越单纯地对生活内容的回归以及描述和解释性的回归,而进行审视... 详细信息

教学所要回归的生活世界不单纯是现实的生活世界,还包括精神层面的生活世界、动态更新的生活世界、未来的生活世界和学生内心的生活世界。在回归生活世界的教学实践中,要超越单纯地对生活内容的回归以及描述和解释性的回归,而进行审视和批判的回归、创造性的回归。

关键词：教学实践生活世界

Tetrahedral framework nucleic acids promote the proliferation and differentiation potential of diabetic bone marrow mesenchymal stem cell

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Chinese Chemical Letters 2024年第9期35卷 284-288页

作者： Yanjing li jiayin li Yuqi chang Yunfeng lin Lei Sui Department of Prosthodontics Tianjin Medical University School and Hospital of StomatologyTianjin 300070China State Key Laboratory of Oral Diseases West China Hospital of StomatologySichuan UniversityChengdu 610041China

Diabetes mellitus considerably affects bone marrow mesenchymal stem cells(BMSCs),for example,by inhibiting their proliferation and differentiation potential,which enhances the difficulty in endogenous bone ***,effective strategies for enhancing the functions of BMSCs in diabetes have farreaching consequences for bone healing and regeneration in diabetes *** framework nucleic acids(tFNAs)are nucleic acid nanomaterials that can autonomously enter cells and regulate their *** this study,we evaluated the effects of tFNAs on BMSCs from diabetic *** found that tFNAs could promote the proliferation,migration,and osteogenic differentiation of BMSCs from rats with type 2 diabetes mellitus,and inhibited cell senescence and ***,tFNAs effectively scavenged the accumulated reactive oxygen species and activated the suppressed protein kinase B(Akt)signaling ***,we show that tFNAs can recover the proliferation and osteogenic potential of diabetic BMSCs by alleviating oxidative stress and activating Akt *** study provides a strategy for endogenous bone regeneration in diabetes and also paves the way for exploiting DNA-based nanomaterials in regenerative medicine.

关键词： Bone marrow mesenchymal stem cell Diabetes mellitus DNA-based nanomaterial Tetrahedral framework nucleic acids Endogenous bone regeneration

An online value iteration method for linear-quadratic mean field social control with unknown dynamics

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Science China(Information Sciences) 2024年第4期67卷 38-39页

作者： Bing-chang WANG Shumei li Ying CAO School of Control Science and Engineering Shandong University

Mean field(MF) models have been widely applied to economics, control theory, and other fields. Its prominent feature is that the individual influence on the overall population is negligible and the impact of the entire system to the single agent is significant and cannot be ignored. As a classical problem in control theory, linear quadratic(LQ) control for MF models has been widely investigated(e.g., [1, 2]).

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Shaking table test study on performance and functionality of a typical telecommunication room after earthquakes

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Earthquake Engineering and Engineering Vibration 2024年第2期23卷 455-474页

作者： li Bo Guo Endong Sun Guoliang ji Shuqiang Mao Chenxi Wang Tao Han Di li Xiaofei Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin 150080China Key Laboratory of Earthquake Disaster Mitigation Ministry of Emergency ManagementHarbin 150080China China Academy of Information and Communications Technology Beijing 100191China School of Architecture Engineering Binzhou UniversityBinzhou 256600China

Large numbers of basic transceiver stations,where the telecommunication room is one of the main components,comprise an important part of the telecommunication *** earthquakes,considerable economic loss from telecommunication systems is often associated with seismic damage and functional loss of the telecommunication ***,research related to this has been *** this study,shaking table tests were conducted for a full-scale typical telecommunication room,including a light-steel house and the necessary communication and power supply *** tests not only focused on the seismic damage to all the structures but also considered the functions of the communication and power supply of the *** interactions between these facilities and their effects on communication function were also *** with the damage to structures,the interruption of the power supply due to earthquakes is a weak ***,the damage indexes,together with their threshold values of different damage states for the communication and power supply equipment,were derived from the test *** results of this research can contribute to the literature gaps regarding seismic performance studies of telecommunication rooms,and can serve as a valuable reference for future research on its seismic fragility and economic losses evaluation.

关键词： telecommunication light-steel house communication equipment power supply equipment seismic performance functionality

Enhanced organic degradation and microbial community cooperation by inoculating Bacillus licheniformis in low temperature composting

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Journal of Environmental Sciences 2024年第9期143卷 189-200页

作者： jing Su Kaiyun Zhou Wenjie Chen Shaoqi Xu Ziwei Feng Yuan chang Xiaoyan Ding Yi Zheng Xingling Tao Ake Zhang Yue Wang ji li Guochun Ding Yuquan Wei Nanjing Institute of Environmental Sciences Ministry of Ecology and EnvironmentNanjing 210042China College of Resources and Environmental Science Beijing Key Laboratory of Biodiversity and Organic FarmingChina Agricultural UniversityBeijing 100193China Organic Recycling Institute(Suzhou)of China Agricultural University Wuzhong DistrictSuzhou 215128China Fuyang Academy of Agricultural Sciences Fuyang 236065China

Microbial activity and interaction are the important driving factors in the start-up phase of food waste composting at low *** aim of this study was to explore the effect of inoculating Bacillus licheniformis on the degradation of organic components and the potential microbe-driven mechanism from the aspects of organic matter degradation,enzyme activity,microbial community interaction,and microbial metabolic *** results showed that after inoculating ***,temperature increased to 47.8℃ on day2,and the degradation of readily degraded carbohydrates(RDC)increased by 31.2%,and the bioheat production increased by 16.5%.There was an obvious enhancement of extracellular enzymes activities after inoculation,especially amylase activity,which increased by 7.68 times on day *** inoculated *** colonized in composting as key genus in the start-up *** network analysis and Mantel test indicated that inoculation drove the cooperation between microbial network modules who were responsible for various organic components(RDC,lipid,protein,and lignocellulose)degradation in the start-up *** function prediction suggested that carbohydrate metabolisms including starch and sucrose metabolism,glycolysis/gluconeogenesis,pyruvate metabolism,etc.,were improved by increasing the abundance of related functional genes after *** conclusion,inoculating *** accelerated organic degradation by driving the cooperation between microbial network modules and enhancing microbial metabolism in the start-up phase of composting.

关键词： Microbial agent Organic matter degradation Microbial interaction Food waste Low temperature composting

ChMYB1-ChbHLH42-ChTTG1 module regulates abscisic acidinduced anthocyanin biosynthesis in Cerasus humilis

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Horticultural Plant Journal 2024年第1期10卷 51-65页

作者： Xiaolong ji Zhe li Mingyu Zhang Shaoyu Lang Xingshun Song State Key Laboratory of Tree Genetics and Breeding Northeast Forestry UniversityHarbinHeilongjiang 150040China Department of Genetics College of Life ScienceNortheast Forestry UniversityHarbinHeilongjiang 150040China

Cerasus humilis is a kind of economic fruit tree peculiar to China,which is widely used in the food,landscape,and pharmaceutical *** are a phenolic metabolite that plays an essential role in fruit ***,the regulatory network of *** in anthocyanin biosynthesis is still *** this study,the R2R3-MYB transcription factor ChMYB1 was isolated from the full genome of the *** one-hybrid,dual-luciferase assays,and GUS staining showed that ChMYB1 significantly increased anthocyanin contents in *** fruit by promoting the expression of ChCHS and ChUFGT by binding MBS(MYB-binding elements).ChMYB1 interacted with ChbHLH42and ChTTG1 to form the MBW complex and further enhanced the expression of *** addition,abscisic acid(ABA)treatment promoted the expression of ChMYB1 and anthocyanin accumulation in *** ***,ABA treatment enhanced the interaction between ChMYB1 and ***,ChABI5 inhibited the interaction between ChMYB1 and *** data elucidated the primary molecular mechanism of anthocyanin biosynthesis in *** fruit,deepening the understanding of the regulatory network affecting anthocyanin metabolism in edible fruit crops.

关键词： Cerasus humilis Anthocyanin ChMYB1 Fruit ABA