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Three-dimensional fracture of UO2 ceramic pellets by phase field modeling

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 169-180页

作者： Wei Xiong xuan Ye Hongzhang Cheng Xiaoming liu Institute of Nuclear and New Energy Technology Collaborative Innovation Center of Advanced Nuclear Energy Technology Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education Tsinghua University State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences School of Engineering Science University of Chinese Academy of Sciences

Fracture is the primary failure type for the UO2ceramic pellets,which are operated under irradiation and thermal processes,and physically confined by the *** this work,by combining closely coupled physical processes of heat conduction,heat transfer,and mechanical deformation with the cohesive phase field framework,we proposed a high-precision modeling of quasistatic cracking of three-dimensional （3D） UO2ceramic fuel pellets under high temperature and *** simulation results agree well with the experimental results,indicating that the proposed method has the potential to capture 3D crack modes in the interested time ***,we studied the relation of the 3D fracture patterns of fuel pellets with the peak power *** was found that the power level plays a critical role in determining the competition between radial and circumferential cracks,as well as transverse penetrating cracks.

关键词： phase field method nuclear fuel pellet coupled thermo-mechanical model thermal fracture

Increased excitatory amino acid transporter 2 levels in basolateral amygdala astrocytes mediate chronic stress–induced anxiety-like behavior

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Neural Regeneration Research 2025年第6期20卷 1721-1734页

作者： Xirong Xu Shoumin xuan Shuai Chen Dan liu Qian Xiao Jie Tu Shenzhen Key Laboratory of Neuroimmunomodulation for Neurological Diseases Shenzhen-Hong Kong Institute of Brain ScienceShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong ProvinceChina CAS Key Laboratory of Brain Connectome and Manipulation Brain Cognition and Brain Disease Institute(BCBDI)Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong ProvinceChina Guangdong Provincial Key Laboratory of Brain Connectome and Behavior the Brain Cognition and Brain Disease Institute(BCBDI)Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong ProvinceChina University of Chinese of Academy of Sciences BeijingChina Faculty of Life and Health Sciences Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong ProvinceChina

The conventional perception of astrocytes as mere supportive cells within the brain has recently been called into question by empirical evidence, which has revealed their active involvement in regulating brain function and encoding behaviors associated with ***, astrocytes in the basolateral amygdala have been found to play a role in the modulation of anxiety-like behaviors triggered by chronic stress. Nevertheless, the precise molecular mechanisms by which basolateral amygdala astrocytes regulate chronic stress–induced anxiety-like behaviors remain to be fully elucidated. In this study, we found that in a mouse model of anxiety triggered by unpredictable chronic mild stress, the expression of excitatory amino acid transporter 2 was upregulated in the basolateral amygdala. Interestingly, our findings indicate that the targeted knockdown of excitatory amino acid transporter 2 specifically within the basolateral amygdala astrocytes was able to rescue the anxiety-like behavior in mice subjected to stress. Furthermore, we found that the overexpression of excitatory amino acid transporter 2 in the basolateral amygdala, whether achieved through intracranial administration of excitatory amino acid transporter 2agonists or through injection of excitatory amino acid transporter 2-overexpressing viruses with GfaABC1D promoters, evoked anxiety-like behavior in mice. Our single-nucleus RNA sequencing analysis further confirmed that chronic stress induced an upregulation of excitatory amino acid transporter 2 specifically in astrocytes in the basolateral amygdala. Moreover, through in vivo calcium signal recordings, we found that the frequency of calcium activity in the basolateral amygdala of mice subjected to chronic stress was higher compared with normal *** knocking down the expression of excitatory amino acid transporter 2 in the basolateral amygdala, the frequency of calcium activity was not significantly increased, and anxiety-like behavior was ob

关键词： anxiety astrocytes basolateral amygdala behavior dihydrokainic acid excitatory amino acid transporter 2 fiber photometry glutamate LDN-212320 transporter

Resolving the developmental mechanisms of cardiac microthrombosis of SARS-CoV-2 based on single-cell transcriptome analysis

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Science China Life Sciences 2025年第1期 103-115页

作者： Xizi Luo Nan Zhang Yuntao liu Beibei Du xuan Wang Tianxu Zhao Bingqiang liu Shishun Zhao Jiazhang Qiu Guoqing Wang State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases Key Laboratory for Zoonosis Research of the Ministry of EducationCollege of Basic MedicineJilin University State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases Key Laboratory for Zoonosis Research of the Ministry of EducationCollege of Veterinary MedicineJilin University College of Mathematics Jilin University Bioinformatic Lab School of MathematicsShandong University Department of Cardiology China-Japan Union HospitalJilin University

The coronavirus disease 2019（COVID-19） outbreak caused by the severe acute respiratory syndrome coronavirus-2（SARS-CoV-2） developed into a global health emergency. Systemic microthrombus caused by SARS-CoV-2 infection is a common complication in patients with COVID-19. Cardiac microthrombosis as a complication of SARS-CoV-2 infection is the primary cause of cardiac injury and death in patietns with severe COVID-19. In this study, we performed single-cell sequencing analysis of the right ventricular free wall tissue from healthy donors,patients who died during the hypercoagulable period of characteristic coagulation abnormality（CAC）, and patients who died during the fibrinolytic period of CAC. We collected 61,187 cells enriched in 24 immune cell subsets and 13 cardiac-resident cell subsets. We found that in the course of SARS-CoV-2 infected heart microthrombus, MYO1EhighRASGEF1Bhighmonocyte-derived macrophages promoted hyperactivation of the immune system and initiated the extrinsic coagulation pathway by activating chemokines CCL3, CCL5. This series of events is the main cause of cardiac microthrombi following SARS-CoV-2 infection. In a SARS-CoV-2 infected heart microthrombus, excessive immune activation is accompanied by an increase in cellular iron content, which in turn promotes oxidative stress and intensifies intercellular competition. This induces cells to alter their metabolic environment, resulting in increased sugar uptake via the glycosaminoglycan synthesis pathway. In addition, high levels of reactive oxygen species generated by elevated iron levels promote increased endogenous malondialdehyde synthesis in a subpopulation of cardiac endothelial cells. This exacerbates endothelial cell dysfunction and exacerbates the coagulopathy process.

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汉语作为方法:从早期文字记录看汉语诗学的当代价值

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河北学刊 2025年第1期45卷 67-73页

作者：张晶刘璇中国传媒大学辽宁师范大学文学院

汉语兼具“文”与“言”的双重属性,与以“言”为主的印欧语相区别。语法与逻辑的同根同源使印欧语在理论表述中陷入了概念与经验的争执,而汉语贯通形而上与形而下的特质使汉语表述本身即构成一种方法。作为“道”之文的载体,中国早期... 详细信息

汉语兼具“文”与“言”的双重属性,与以“言”为主的印欧语相区别。语法与逻辑的同根同源使印欧语在理论表述中陷入了概念与经验的争执,而汉语贯通形而上与形而下的特质使汉语表述本身即构成一种方法。作为“道”之文的载体,中国早期记录及其文法结构提供了关键信息,甲骨卜辞的体例制式为“易”类文献的结构提供了可追溯的原型,也为探索“论出于易”对汉语诗学功能的塑造提供了重要线索。其中,干支配伍的宇宙纪日为“以时系事”的话语表述提供了超线性时空结构;“正反对贞”以对言的形式表现语义的动态平衡与赋形必变的道理;“主题+阐释”的体例结构以逐层累积的文本层次为断言的疑难提供了积极的方案。汉语文法能够在表述判断的同时保持对“变”的关切,这为建构既能规范描述艺术经验又能直面人类自身处境的理论话语提供了时代价值。

关键词：汉语早期文字记录文法结构汉语诗学当代价值

Evolution of Transitional Institutions for Urban Land Redevelopment in China——Case in Guangzhou

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Chinese Geographical Science 2009年第1期19卷 1-7页

作者： liu xuan School of Geography and Planning SUN Yat-Sen University Guangzhou 510275 China

Building effective institutions for markets is a great challenge to China's transitional economy. China's experience in establishing urban land markets is characterized by trial and error and the gradual evolution of transitional institutions. Based on archive data and interviews in a neighborhood(Jinhuajie) of Guangzhou,this research reveals that China's land redevelopment in the past two decades has followed an approach of partial and gradual reform,which was structured by the gradual evolution of transitional institutions to speed up local land redevelopment within the existing property rights system. Transitional institutions,including highly compensated residents' land use rights,in-kind land lease payment,flexible control on development rights of developers and short-term actual ownership of work units,are generated by the local government sequentially to dispel existing land use rights of different land users and make further development be able to follow market mechanisms.

关键词： land redevelopment evolution of transitional institutions property rights Guangzhou

一种缓释型ε-PL PA6复合材料的制备及其抗菌性能

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石油炼制与化工 2025年第1期56卷 40-48页

作者：王璇李伟李泽阳刘伟中石化石油化工科学研究院有限公司北京100083

以尼龙6(PA6)和聚赖氨酸(ε-PL)为原料,采用溶液共混方法制备了一系列不同ε-PL含量的ε-PL PA6复合材料,并利用扫描电镜、热重分析、差示扫描量热仪以及X射线衍射等方法对ε-PL PA6复合材料结构与性能进行了系统研究。结果表明:当ε-P... 详细信息

以尼龙6(PA6)和聚赖氨酸(ε-PL)为原料,采用溶液共混方法制备了一系列不同ε-PL含量的ε-PL PA6复合材料,并利用扫描电镜、热重分析、差示扫描量热仪以及X射线衍射等方法对ε-PL PA6复合材料结构与性能进行了系统研究。结果表明:当ε-PL质量分数为15%时,ε-PL在PA6中分散最均匀;ε-PL PA6两种材料复合对PA6晶型无影响,但其结晶温度升高、熔点降低;压片型ε-PL PA6复合材料样品中的ε-PL能够在水中持续缓慢释放,缓释过程符合Logistic模型;ε-PL质量分数为10%~20%的ε-PL PA6复合材料表现出良好的溶出抗菌性和表面抗菌性,对大肠杆菌和金黄色葡萄球菌的表面抗菌率均大于99.99%,是兼具表面抗菌和缓释抗菌功能的新型高分子复合抗菌材料。

关键词：尼龙6 聚赖氨酸缓释抗菌复合材料

Super-Planckian thermal radiation enabled by hyperbolic surface phonon polaritons

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Science China(Technological Sciences) 2016年第11期59卷 1680-1686页

作者： liu XiangLei xuan YiMin School of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics School of Energy and Power Engineering Nanjing University of Science and Technology

Excitation of surface resonance modes and presence of resonance-free hyperbolic modes are two common ways to enhance the near-field radiative energy transport, which can find wide applications in noncontact thermal management and energy ***, we identify another way to achieve the super-Planckian thermal radiation via hyperbolic surface phonon polaritons(HSPhPs). Based on the fluctuation-dissipation theory, the near-field radiative heat flux between bulk hexagonal boron nitride(hBN) planes with the optical axis perpendicular to the radiative energy flow can be 120 times as large as the blackbody limit for a gap distance of 20 nm. When the film thickness is reduced to 10 nm, the radiative heat flux is found to increase by 26.3%.The underlying mechanism is attributed to the coupling of Type I HSPhPs inside the anisotropic hBN film, which improves the energy transmission coefficient over a broad wavevector space especially for waves with extremely high wavevectors. This work helps to deepen the understanding of near-field radiation between natural hyperbolic materials, and opens a new route to enhance the near-field thermal radiation.

关键词： near-field thermal radiation hyperbolic surface phonon polaritons hexagonal boron nitride

A new track for antibacterial treatment:Progress and challenges of using cytomembrane-based vesicles to combat bacteria

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Particuology 2023年第7期78卷 136-146页

作者： Jiaxuan Xie xuan liu Gang liu State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics National Institute of Diagnostics and Vaccine Development in Infectious DiseasesSchool of Life SciencesSchool of Public HealthXiamen UniversityXiamen361102China Center for Molecular Imaging and Translational Medicine School of Public HealthXiamen UniversityXiamen361102China

The emergence and re-emergence of antibiotic-resistant bacteria,especially superbugs,are leading to complicated infections that are increasingly difficult to ***,novel alternative antimicrobial therapies are urgently needed to reduce the morbidity and mortality caused by antibiotic *** development of biomimetic-based therapy is expected to provide innovative means for addressing this challenging *** a kind of novel biomaterial,cytomembrane-based vesicles(MVs)continue to receive considerable attention in antimicrobial therapy owing to their inherent biocompatibility,design flexi-bility,and remarkable ability to interact with biological molecules or the surrounding *** remarkable cell-like properties and their inherent interaction with pathogens,toxins,and the immune system underlie MVs-based functional protein therapy and targeted delivery to develop advanced therapeutic strategies against bacterial *** review provides a fundamental under-standing of the characteristics and physiological functions of cytomembrane-based vesicles,focusing on their potential to combat bacterial infections,including detoxification,immune modulation,antibiotics delivery,and physical *** addition,the future possibilities and remaining challenges for clinically implementing MVs in the field of antibacterial treatment are discussed.

关键词： Cytomembrane-basedvesicles Bacterial resistance Antibacterial therapy Drug delivery

Electromagnetic and Microwave Absorption Properties of Fe Coating on SiC with Metal Organic Chemical Vapor Reaction

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Chinese Physics Letters 2014年第4期31卷 167-169页

作者： liu Yuan liu Xiang-xuan WANG xuan-Jun WEN Wu No. 603 Faculty Xi'an Institute of High Technology Xi'an 710025

SiC-Fe composites are prepared by metal organic chemical vapor deposition （MOCVD） using silicon carbide （SIC＇） and iron pentacarbonyl （Fe（CO）5） as the precursors. The structure and morphology analyses demonstrate that the Fe nanoparticles have been deposited on the surface of the SiC particles. In terms of reflection loss （RL）, the absorbing frequency band （AFB, the value of RL 〈 -10 dB）, and the matching thickness （tin）, SiC-Fe composites show the best performances： minimum RL of - 31.6 dB with tm= 2.0 mm at 15.1 GHz, AFB of 12.9-17.3 OHz, indicating that Fe-doped SiC by MOCVD can significantly improve the electromagnetic properties of SiC and that SiC-Fe composites could be used as an effective microwave absorption materiM.

关键词： SURFACE coatings METAL organic chemical vapor deposition SILICON carbide -- Electric properties MICROWAVE materials ABSORPTION (Physiology)