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Toughening ultrastrong low-density steel by textured δ-ferrite lamellas

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Defence Technology（防务技术） 2024年第2期32卷 405-411页

作者： Bin Hu Guosen Zhu Guohui Shen Zheng Wang Qinghua Wen Xiao Shen Haiwen luo School of Metallurgical and Ecological Engineering University of Science and Technology BeijingXue Yuan Rd.30Beijing 100083China Shougang Research Institute of Technology Yangzhuang Street 69Beijing 100043China Steel Institute RWTH Aachen UniversityIntzestraße 152072AachenGermany

By both the Charpy V-notched impact and the projectile tests, we here investigated the dynamic fracture behavior of a recently developed ultrastrong lightweight steel comprising a hierarchical martensitic matrix, dispersed ultra-fine-retained austenite grains and oriented δ-ferrite lamellas, the latter being due to high Al and si contents employed for low-density design. This steel shows a superior combination of specific ultimate tensile strength and impact toughness to other ultrastrong steels and has successfully arrested a real steel-cored bullet shot. These are attributed to the densely textured δ-ferrite lamellas that can deflect the propagating cracks until they are trapped and enclosed besides austenite-to-martensite transformation crack closure, leading to more energy consumed before failure. These results suggest a new pathway for toughening ultrastrong lightweight steels.

关键词： Ultrastrong and light steel d-Ferrite lamellas Crack propagation Toughness

Impact of Initial Soil Conditions on Soil Hydrothermal and Surface Energy Fluxes in the Permafrost Region of the Tibetan Plateau

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Advances in Atmospheric Sciences 2024年第4期41卷 717-736页

作者： siqiong luo Zihang CHEN Jingyuan WANG Tonghua WU Yao XIAO Yongping QIAO Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Cryosphere Research Station on the Qinghai-Tibet Plateau State Key Laboratory of Cryospheric ScienceNorthwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China

Accurate initial soil conditions play a crucial role in simulating soil hydrothermal and surface energy fluxes in land surface process *** study emphasized the influence of the initial soil temperature(ST)and soil moisture(SM)conditions on a land surface energy and water simulation in the permafrost region in the Tibetan Plateau(TP)using the Community Land Model version 5.0(CLM5.0).The results indicate that the default initial schemes for ST and SM in CLM5.0 were simplistic,and inaccurately represented the soil characteristics of permafrost in the TP which led to underestimating ST during the freezing period while overestimating ST and underestimating SLW during the thawing period at the XDT *** the long-term spin-up method to obtain initial soil conditions has only led to limited improvement in simulating soil hydrothermal and surface energy *** modified initial soil schemes proposed in this study comprehensively incorporate the characteristics of permafrost,which coexists with soil liquid water(SLW),and soil ice(si)when the ST is below freezing temperature,effectively enhancing the accuracy of the simulated soil hydrothermal and surface energy ***,the modified initial soil schemes greatly improved upon the results achieved through the long-term spin-up *** modified initial soil schemes experiments resulted in a 64%,88%,and 77%reduction in the average mean bias error(MBE)of ST,and a 13%,21%,and 19%reduction in the average root-mean-square error(RMSE)of SLW compared to the default simulation ***,the average MBE of net radiation was reduced by 7%,22%,and 21%.

关键词： initial soil conditions soil temperature soil liquid water soil ice surface energy fluxes permafrost

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环境规制对旅游经济韧性的影响研究

湖南财政经济学院学报 2024年第3期40卷 26-35页

作者：生延超谭左思罗子怡湖南工商大学公共管理与人文地理学院湖南长沙410205

环境规制是实现旅游绿色发展的重要手段,对于提升我国旅游经济韧性具有重要意义。选取我国30个省份2011—2020年的面板数据,利用熵值法计算环境规制和旅游经济韧性,验证了环境规制对旅游经济韧性的直接影响和作用机制,得出以下结论:环... 详细信息

环境规制是实现旅游绿色发展的重要手段,对于提升我国旅游经济韧性具有重要意义。选取我国30个省份2011—2020年的面板数据,利用熵值法计算环境规制和旅游经济韧性,验证了环境规制对旅游经济韧性的直接影响和作用机制,得出以下结论:环境规制对旅游经济韧性具有显著的正向影响,环境规制强度越高,对旅游经济韧性的提升作用越大。人力资本结构优化和旅游产业升级是环境规制影响我国旅游经济韧性的重要机制。异质性分析表明环境规制对旅游经济韧性的影响具有经济发展水平和市场化程度异质性,相较于经济欠发达地区,经济发达地区环境规制对旅游经济韧性的提升作用更明显;在市场化水平较高的地区,环境规制能提升旅游经济韧性,而在市场化水平较低的地区,环境规制对旅游经济韧性的影响不明显。

关键词：环境规制旅游经济韧性人力资本旅游产业升级

维普期刊数据库博看期刊

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以尿崩症起病的脂质肉芽肿病1例

中华内科杂志 2024年第7期63卷 699-701页

作者：黄婧郭慕瑶罗卉左晓霞中南大学湘雅医院风湿免疫科湖南省风湿免疫病临床医学研究中心国家老年疾病临床医学研究中心(湘雅医院)长沙410008

患者男性60岁,病程1年余。以垂体占位引起的中枢性尿崩症起病,伴主动脉周围软组织包绕、腹膜后病变、渗出性多浆膜腔积液、长骨受累,临床表现类似IgG 4相关性疾病。查血IgG 4浓度正常(0.928 g/L)。左胫骨上段骨病变组织活检病理检查,确... 详细信息

患者男性60岁,病程1年余。以垂体占位引起的中枢性尿崩症起病,伴主动脉周围软组织包绕、腹膜后病变、渗出性多浆膜腔积液、长骨受累,临床表现类似IgG 4相关性疾病。查血IgG 4浓度正常(0.928 g/L)。左胫骨上段骨病变组织活检病理检查,确诊脂质肉芽肿病(Erdheim-Chester病)。予泼尼松(50 mg每日1次)、沙利度胺(100 mg每晚1次)、去氨加压素(0.05 g每日1次)治疗,1个月后患者气促、多尿症状改善,随访半年患者胸腔积液未再增多。通过对本例的分析和总结,临床医生应提高对脂质肉芽肿病这类少见疾病的关注和认识,了解其与IgG 4相关性疾病的鉴别要点,降低误诊和漏诊率。

关键词： IgG 4相关性疾病 Erdheim-Chester病中枢性尿崩症

The enhanced mechanical properties of siC nanowires/Ba_(0.75)Sr_(0.25)Al_(2)si_(2)O_(8) ceramics with embedded siO_(2) interface

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Journal of Advanced Ceramics 2024年第7期13卷 933-941页

作者： Xin Li Xiaomeng Fan Haojie luo Xiaoke Lu Jimei Xue Fang Ye Yongsheng Liu Science and Technology on Thermostructural Composite Materials Laboratory Northwestern Polytechnical UniversityXi’an 710072China Frontier Institute of Science and Technology Xi’an Jiaotong UniversityXi’an 710049China

In this work,low-softening-temperature and low-modulus siO_(2) was introduced as an embedded interface between siC nanowires(siCnws)and a Ba_(x)Sr_(1−x)Al_(2)si_(2)O_(8) ceramic matrix to enhance strength and toughness of the *** the sintering process,molten siO_(2) enhances the flowability of the ceramic powders and modifies the dispersion of *** strengthening effect of siCnws was fully realized,and the flexural strength of the optimized ceramics reached 193±16 MPa,which represents an increase of 52.6%.After the formation of the embedded siO_(2) interface with a low modulus,cracks can deflect along the siCnws surface,which is consistent with the criterion of He and *** can effectively extend the crack propagation path,and the fracture toughness(K_(IC))is thus improved by 94.0%,reaching 3.1±0.5 MPa·m^(1/2).

关键词： multiphase ceramics siO_(2) interface densification mechanical properties

Durable dual-state duplex si-HfO_(2)with excellent oxidation and cracking resistance

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Journal of Advanced Ceramics 2024年第3期13卷 388-401页

作者： Lin Chen Jing-Chuan luo Wen-Qi Yang Chang-Jiu Li Guan-Jun Yang State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an 710049China Xi’an Aerospace Engine Company Limited in CASC Xi’an 710065China

The lifetime of si bond coatings in environmental barrier coatings is constrained by phase-transition-induced cracking of the siO_(2)*** this study,si-HfO_(2)dual-state duplex composite materials are proposed to address this issue by partially forming HfsiO_(4)and minimizing the siO_(2)*** as-prepared composite exhibited a structure comprising discrete HfO_(2)“bricks”embedded in a continuous si“mortar”,while the oxidized state transformed into discrete HfsiO_(4)“bricks”within continuous thin siO_(2)“mortars”.The results indicate that continuous thin siO_(2)contributes to reducing the oxidation rate to a level comparable to that of pure si,and discrete HfsiO_(4)particles aid in relieving phase transition-induced stress and inhibiting crack propagation,thereby enhancing oxidation and cracking resistance ***,the composite with 20 mol%HfO_(2)and a mean particle size of~500 nm at 1370℃exhibited a service lifetime 10 times greater than that of pure *** research provides valuable insights for designing si-based bond coatings with improved service lifetime.

关键词： oxidation environmental barrier coatings(EBCs) phase transition cracking bond coatings

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等应变条件下增压式真空预压固结解析解

岩土力学 2024年第3期45卷 809-821页

作者：刘景锦罗学思雷华阳郑刚罗昊鹏天津大学建筑工程学院天津300350 天津大学滨海土木工程结构与安全教育部重点实验室天津300350

从注气增压对土体作用效果的角度出发,建立增压式真空预压固结解析理论模型。提出基于注气增压压力等效的受力简化模型;引入新参数——径向渗透系数增大系数η,反映注气过程对土体渗透性质的改变。根据Barron等应变假定和达西定律,考虑... 详细信息

从注气增压对土体作用效果的角度出发,建立增压式真空预压固结解析理论模型。提出基于注气增压压力等效的受力简化模型;引入新参数——径向渗透系数增大系数η,反映注气过程对土体渗透性质的改变。根据Barron等应变假定和达西定律,考虑排水板涂抹效应与井阻作用、土体径-竖向渗流以及上部堆载,推导增压式真空预压固结控制方程及其解析解,并利用弹性力学方法推导等效注气增压压力p(t)的计算公式。针对瞬时增压和线性增压两种特例给出具体解析解公式,并通过与工程案例对比分析,验证了解析解及等效力计算方法的合理性。通过对固结性状的分析得出如下结论:注气增压方法可增大土体负孔隙水压力值,加速土体排水固结;“参数η”对固结速率的影响较大,分析模型中考虑注气过程对径向渗透系数的改变会更加合理;井阻作用会导致土体固结速率减慢,径-竖向渗流时孔压能够消散完成,而只有径向渗流时孔压无法消散完成。

关键词：增压式真空预压等应变条件固结理论解析解

Plasmon-enhanced ultra-high photoresponse of single-wall carbon nanotube/copper/silicon near-infrared photodetectors

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Nano Research 2024年第7期17卷 5930-5936页

作者： Yi-Ming Zhao Xian-Gang Hu Chao Chen zuo-Hua Wang An-Ping Wu Hong-Wang Zhang Peng-Xiang Hou Chang Liu Hui-Ming Cheng Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China National Engineering Research Center for Equipment and Technology of Cold Strip Rolling College of Mechanical EngineeringYanshan UniversityQinhuangdao 066004China Faculty of Materials Science and Engineering/Institute of Technology for Carbon Neutrality Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

single wall carbon nanotube(SWCNT)/si heterojunction photodetectors have the advantages of high photoresponse ability and simple structure,however,their detection wavelength range are usually lower than 1100 nm,which limits their application in the infrared *** report a SWCNT/Cu/si photodetector with both a high photoresponse and a detection range up to the infrared band by depositing a Cu nanoparticles(NPs)layer between a SWCNT film and a n-si *** was found that the Cu NPs produce strong surface plasmon resonance(SPR)under laser irradiation,which breaks through the limitation of si band gap and greatly improves the photoresponse of the SWCNT/Cu/si photodetector in the near infrared *** responsivity(R)of the photodetector in the wavelength range of 1850–1200 nm reached 2.2–14.15 mA/W,which is the highest value in the reported plasmon enhanced n-si based photodetectors,and about 20,000 times higher than that of a SWCNT/si *** R value for 1550 nm wavelength used in optical communications reached~8.2 mA/W,which is 64%higher than the previously reported values of commonly used *** attribute the significant increase to the strong SPR and low Schottky barrier of Cu with n-si,which facilitates the generation and transfer of the carriers.

关键词： single wall carbon nanotube photodetector silicon surface plasmon resonance copper

DNA methylation clocks for estimating biological age in Chinese cohorts

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Protein & Cell 2024年第8期15卷 575-593页

作者： Zikai Zheng Jiaming Li Tianzi Liu Yanling Fan Qiao-Cheng Zhai Muzhao Xiong Qiao-Ran Wang Xiaoyan Sun Qi-Wen Zheng Shanshan Che Beier jiang Quan Zheng Cui Wang Lixiao Liu Jiale Ping si Wang Dan-Dan Gao Jinlin Ye Kuan Yang Yuesheng zuo Shuai Ma Yun-GuiYang Jig Qu Feng Zhang Peilin Jia Guang-Hui Liu Weiqi Zhang CAS Key Laboratory of Genomic and Precision Medicine Beijing Institute of GenomicsChinese Academy of Sciences and China National Center for BioinformationBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China CAS Key Laboratory of Computational Biology Shanghai Institute of Nutrition and HealthChinese Academy of SciencesShanghai 200031China Division of Orthopaedics Quzhou Affliated Hospital of Wenzhou Medical UniversityQuzhou 324000China The Joint Innovation Center for Engineering in Medicine Quzhou Affliated Hospital of Wenzhou Medical UniversityQuzhou 324000China Advanced Innovation Center for Human Brain Protection and National Clinical Research Center for Geriatric DisordersXuanwu Hospital Capital Medical UniversityBeijing 100053China Aging Translational Medicine Center International Center for Aging and CancerXuanwu HospitalCapital Medical UniversityBeijing 100053China Aging Biomarker Consortium Beijing 100101China State Key Laboratory of Membrane Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China Key Laboratory of Organ Regeneration and Reconstruction Institute of ZoologyChinese Academy of SciencesBeijing 100101China nstitute for Stem Cell and Regeneration Chinese Academy of SciencesBeijing 100101China Beijing Institute for Stem Cell and Regenerative Medicine Beijing 100101China State Key Laboratory of Stem Cell and Reproductive Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China National Genomics Data Center Beijing Institute of GenomicsChinese Academy of Sciences and China National Center for BioinformationBeijing 100101China

Epigenetic clocks are accurate predictors of human chronological age based on the analysis of DNA methylation(DNAm)at specific CpG ***,a systematic comparison between DNA methylation data and other omics datasets has not yet been ***,available DNAm age predictors are based on datasets with limited ethnic *** address these knowledge gaps,we generated and analyzed DNA methylation datasets from two independent Chinese cohorts,revealing age-related DNAm ***,a DNA methylation aging clock(iCAS-DNAmAge)and a group of DNAm-based multi-modal clocks for Chinese individuals were developed,with most of them demonstrating strong predictive capabilities for chronological *** clocks were further employed to predict factors influencing aging *** DNAm aging clock,derived from multi-modal aging features(compositeAge-DNAmAge),exhibited a close association with multi-omics changes,lifestyles,and disease status,underscoring its robust potential for precise biological age *** findings offer novel insights into the regulatory mechanism of age-related DNAm changes and extend the application of the DNAm clock for measuring biological age and aging pace,providing the basis for evaluating aging intervention strategies.

关键词： DNA methylation aging clock aging age prediction