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In situ TEM observations and molecular dynamics simulations of deformation defect activities in Mg via nanoindentation

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Journal of Magnesium and Alloys 2023年第12期11卷 4513-4524页

作者： yi-cheng lai Yubin ying Digvijay Yadav Jose Guerrero Yong-Jie Hu Kelvin Y.Xie Department of Materials Science and Engineering Texas A&M UniversityCollege StationTX 77845USA Department of Materials Science and Engineering Drexel UniversityPhiladelphiaPA 19104USA

In this work, we performed in situ nanoindentation in TEM to capture the real-time dislocation and twinning activities in pure Mg during loading and unloading. We demonstrated that the screw component of dislocations glides continuously, while the edge components rapidly become sessile during loading. The twin tip propagation is intermittent, whereas the twin boundary migration is more continuous. During unloading, we observed the elastic strain relaxation causes both dislocation retraction and detwinning. Moreover,we note that the plastic zone comprised of dislocations in Mg is well-defined, which contrasts with the diffused plastic zones observed in face-centered cubic metals under the nanoindentation impressions. Additionally, molecular dynamics simulations were performed to study the formation and evolution of deformation-induced crystallographic defects at the early stages of indentation. We observed that,in addition to dislocations, the I1stacking fault bounded with a Frank loop can be generated from the plastic zone ahead of the indenter, and potentially serve as a nucleation source for abundant dislocations observed experimentally. These new findings are anticipated to provide new knowledge on the deformation mechanisms of Mg, which are difficult to obtain through conventional ex situ approaches. These observations may serve as a baseline for simulation work that investigate the dynamics of dislocation slip and twinning in Mg and alloys.

关键词： In situ TEM Molecular dynamics simulation Dislocation Twinning Mg Nanoindentation

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Pathogenesis, diagnosis, and treatment of epilepsy: electromagnetic stimulation-mediated neuromodulation therapy and new technologies

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Neural Regeneration Research 2025年第4期20卷 917-935页

作者： Dian Jiao lai Xu Zhen Gu Hua Yan Dingding Shen Xiaosong Gu Academy of Medical Engineering and Translational Medicine Tianjin UniversityTianjinChina Key Laboratory of Advanced Drug Delivery Systems of Zhejiang Province College of Pharmaceutical SciencesZhejiang UniversityHangzhouZhejiang ProvinceChina Affiliated Hospital of Nantong University NantongJiangsu ProvinceChina

Epilepsy is a severe,relapsing,and multifactorial neurological *** regarding the accurate diagnosis,prognosis,and in-depth pathogenesis are crucial for the precise and effective treatment of *** pathogenesis of epilepsy is complex and involves alterations in variables such as gene expression,protein expression,ion channel activity,energy metabolites,and gut microbiota *** results are lacking for conventional treatments for *** resection of lesions,drug therapy,and non-drug interventions are mainly used in clinical practice to treat pain associated with ***-pharmacological treatments,such as a ketogenic diet,gene therapy for nerve regeneration,and neural regulation,are currently areas of research *** review provides a comprehensive overview of the pathogenesis,diagnostic methods,and treatments of *** also elaborates on the theoretical basis,treatment modes,and effects of invasive nerve stimulation in neurotherapy,including percutaneous vagus nerve stimulation,deep brain electrical stimulation,repetitive nerve electrical stimulation,in addition to non-invasive transcranial magnetic stimulation and transcranial direct current *** studies have shown that electromagnetic stimulation-mediated neuromodulation therapy can markedly improve neurological function and reduce the frequency of epileptic ***,many new technologies for the diagnosis and treatment of epilepsy are being ***,current research is mainly focused on analyzing patients’clinical manifestations and exploring relevant diagnostic and treatment methods to study the pathogenesis at a molecular level,which has led to a lack of consensus regarding the mechanisms related to the disease.

关键词： diagnosis drug treatment electroencephalography epilepsy monitoring epilepsy nerve regeneration neurostimulation non-drug interventions pathogenesis prediction

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Molecular simulation study of the microstructures and properties of pyridinium ionic liquid[HPy][BF_(4)]mixed with acetonitrile

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原子与分子物理学报 2025年第4期42卷 27-32页

作者： XU Jian-Qiang MA Zhao-Peng cheng Si LIU Zhi-Cong ZHU Guang-lai Department of Physics School of Physics and Electronic InformationAnhui Normal UniversityWuhu 241002China

The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this *** following properties were determined:density,self-diffusion coefficient,excess molar volume,and radial distribution *** results show that with an increase in the mole fraction of[HPy][BF_(4)],the self-diffusion coefficient ***,the excess molar volume initially decreases,reaches a minimum,and then *** rules of radial distribution functions(RDFs)of characteristic atoms are *** increasing the mole fraction of[HPy][BF_(4)],the first peak of the RDFs of HA1-F decreases,while that of CT6-CT6 rises at first and then *** indicates that the solvent molecules affect the polar and non-polar regions of[HPy][BF_(4)]differently.

关键词： Pyridinium ionic liquids Thermodynamic properties Molecular dynamics simulation Radial distribution functions

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Ab initio Study on Structures and Isomerization of Magnesium Fluorosilylenoid H2SiFMgF

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Chinese Journal of Chemical Physics 2008年第6期21卷 541-546页

作者： yi-jian Zhang Mei-jiang Li Guo-qiao lai Da-cheng Feng Sheng-yu Feng Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education Hangzhou Normal University Hangzhou 310012 China School of Chemistry and Chemical Engineering Shandong University Ji'nan 250100 China

The structures and isomerization of magnesium fluorosilylenoid H2SiFMgF were investigated by ab initio molecular orbital theory. Four equilibrium structures and three isomeric transition states were located and fully optimized at the B3LYP/6-31G（d,p） and G3MP2B3 levels, respectively. Based on the B3LYP/6- 31G（d,p） optimized geometries, harmonic frequencies of various structures were obtained and 29Si chemical shifts were calculated. The solvent effects were investigated by means of the polarizable continuum model using THF as a solvent at B3LYP/6-31G（d,p） level. Isomerization paths for isomers were confirmed by intrinsic reaction coordinate calculations. The calculated results show that tetrahedral structure has the lowest energy and is the most stable; tetrahedral, three-membered ring, and p-complex structures are suggested to be the experimentally detectable ones; and a-complex structure has the highest energy and will not exist.

关键词： Magnesium fluorosilylenoid Ab initio calculation B3LYP/6-31G(d p) theory Isomerization

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Meningeal lymphatic vessel crosstalk with central nervous system immune cells in aging and neurodegenerative diseases

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Neural Regeneration Research 2025年第3期20卷 763-778页

作者： Minghuang Gao Xinyue Wang Shijie Su Weicheng Feng Yaona lai Kongli Huang Dandan Cao Qi Wang Science and Technology Innovation Center Guangzhou University of Chinese MedicineGuangzhouGuangdong ProvinceChina Institute of Clinical Pharmacology Guangzhou University of Chinese MedicineGuangzhouGuangdong ProvinceChina The Sixth Affiliated Hospital Sun Yat-sen UniversityGuangzhouGuangdong ProvinceChina

Meningeal lymphatic vessels form a relationship between the nervous system and periphery, which is relevant in both health and disease. Meningeal lymphatic vessels not only play a key role in the drainage of brain metabolites but also contribute to antigen delivery and immune cell activation. The advent of novel genomic technologies has enabled rapid progress in the characterization of myeloid and lymphoid cells and their interactions with meningeal lymphatic vessels within the central nervous system. In this review, we provide an overview of the multifaceted roles of meningeal lymphatic vessels within the context of the central nervous system immune network, highlighting recent discoveries on the immunological niche provided by meningeal lymphatic vessels. Furthermore, we delve into the mechanisms of crosstalk between meningeal lymphatic vessels and immune cells in the central nervous system under both homeostatic conditions and neurodegenerative diseases, discussing how these interactions shape the pathological outcomes. Regulation of meningeal lymphatic vessel function and structure can influence lymphatic drainage, cerebrospinal fluid-borne immune modulators, and immune cell populations in aging and neurodegenerative disorders, thereby playing a key role in shaping meningeal and brain parenchyma immunity.

关键词： central nervous system meningeal lymphatic vessels immunity myeloid cells lymphatic cells neurodegenerative disease

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Computation model and improved ACO algorithm for p//T

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Journal of Systems Engineering and Electronics 2009年第6期20卷 1336-1343页

作者： yi Yang lai Jieling School of Information Science & Technology Sun Yat-sen Univ. Guangzhou 510275 P. R. China

Scheduling jobs on parallel machines to minimize the total tardiness（p//T） is proved to be NP hard.A new ant colony algorithm to deal with p//T（p//T ACO） is addressed, and the computing model of mapping p//T to the ant colony optimization environment is ***, based on the academic researches on p//T, some new properties used in the evolutionary computation are analyzed and *** theoretical analysis and comparative experiments demonstrate that p//T ACO has much better performance and can be used to solve practical large scale problems efficiently.

关键词： scheduling evolutionary computation ant colony optimization.

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Structural Modal Parameter Recognition and Related Damage Identification Methods under Environmental Excitations: A Review

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Structural Durability & Health Monitoring 2025年第1期19卷 25-54页

作者： Chao Zhang Shang-Xi lai Hua-Ping Wang School of Civil Engineering and Mechanics Lanzhou UniversityLanzhou730000China Key Laboratory of Special Functional Materials and Structural Design Ministry of EducationLanzhou UniversityLanzhou730000China

Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the ***,it is particularly signiﬁcant to identify the structural modal parameters according to the monitoring data information in the structural health monitoring(SHM)system,so as to provide a scientiﬁc basis for structural damage identiﬁcation and dynamic model modiﬁ*** view of this,this paper reviews methods for identifying structural modal parameters under environmental excitation and brieﬂy describes how to identify structural damages based on the derived modal *** paper primarily introduces data-driven modal parameter recognition methods(e.g.,time-domain,frequency-domain,and time-frequency-domain methods,etc.),brieﬂy describes damage identiﬁcation methods based on the variations of modal parameters(e.g.,natural frequency,modal shapes,and curvature modal shapes,etc.)and modal validation methods(e.g.,Stability Diagram and Modal Assurance Criterion,etc.).The current status of the application of artiﬁcial intelligence(AI)methods in the direction of modal parameter recognition and damage identiﬁcation is further *** on the pre-vious analysis,the main development trends of structural modal parameter recognition and damage identiﬁcation methods are given to provide scientiﬁc references for the optimized design and functional upgrading of SHM systems.

关键词： Structural health monitoring data information modal parameters damage identiﬁcation AI method

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Properties and homogeneity of 550-MPa grade TMCP steel for ship hull

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International Journal of Minerals,Metallurgy and Materials 2010年第2期17卷 179-184页

作者： yi Nie cheng-jia Shang Xin Song Yang You Chuang Li Xin-lai He School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Department of Physics and Chemistry Henan Polytechnic University Jiaozuo 454000 China

Ultra low carbon steels by the thermal mechanical control process（TMCP） with less Ni,Cr,and Mo contents have been developed for 550 MPa grade heavy gauge ship hulls and offshore *** relationships among microstructures,process,and properties of the studied steel have been investigated.A series of accurate control technologies have been developed for this kind of *** microalloying and TMCP＋relaxation precipitation control（RPC）＋accelerated cooling process were employed to optimize the mechanical properties and ensure the homogeneity of the 80-mm thick *** microstructures of thin plates slightly changed from surface to center,but the micro-structures of the heavy gauge plate（80 mm） changed *** the simple composition,it can meet the requirement of thin plates by adopting a few *** for thick plates（80 mm）,a little higher Cu and Ni contents should be *** steels can meet the needs without *** these ways,the properties of the steels can be optimized,and the cost can be decreased notably.

关键词： microalloyed steel thick plate microstructure mechanical properties microalloying relaxation precipitation accelerated cooling

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珠江三角洲城市群留鸟多样性格局及其驱动机制

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中山大学学报（自然科学版）（中英文） 2025年第1期64卷 218-227页

作者：叶俊宏刘珍环杨帆魏莱周义广东省粤北岩溶区碳水耦合野外科学观测研究站/中山大学地理科学与规划学院广东广州510006

鸟类是反映城市生境和生物多样性变化的重要指标,城市鸟类多样性分布格局模拟与预测是当前城市生物多样性保护研究中重点关注的难题。珠江三角洲城市群经历了快速的城市化过程,景观变化显著,给城市生境和生物多样性保护带来了巨大挑战... 详细信息

鸟类是反映城市生境和生物多样性变化的重要指标,城市鸟类多样性分布格局模拟与预测是当前城市生物多样性保护研究中重点关注的难题。珠江三角洲城市群经历了快速的城市化过程,景观变化显著,给城市生境和生物多样性保护带来了巨大挑战。为解析城市鸟类多样性与城市生境之间的空间关联机制,构建“单物种分布预测-物种多样性聚类-多样性的影响归因”的空间综合途径,开展珠江三角洲城市群留鸟空间格局与形成机制研究。结果表明:1)珠江三角洲城市群的87种留鸟构成的多样性与适宜性具有高度的城-乡梯度分布模式;将留鸟的空间适宜性聚类可分为8类,总体上留鸟的中高适宜区占比小于30%。2)结构方程模型的解析可以发现,人类活动显著地正向影响了鸟类多样性的空间分布格局,影响系数介于0.28~1.94;而植被、气候、地形的正向或负向效应差异明显。研究可为城市生物多样性保护,调控鸟类多样性的生境影响因素,开展城市生态建设与管理提供科学依据。

关键词：城市生物多样性鸟类 MaxEnt模型结构方程模型

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Cauda equina syndrome with urinary retention as a postoperative complication of lumbar spine surgery:A case report

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World Journal of Clinical Cases 2025年第10期13卷 40-45页

作者： Kai-Wu Yang Wei-Hong lai Da-Wei Huang Department of Urology Chiayi Christian HospitalChiayi 600566Taiwan Department of Neurosurgery Chiayi Christian HospitalChiayi 600566Taiwan

BACKGROUND Cauda equina syndrome(CES)is characterized by a group of symptoms that may be caused by inflammation,spinal cord compression,venous congestion,or *** syndrome is commonly an indication for surgical intervention but has not been determined as a postoperative complication following surgery for lumbar spine *** SUMMARY To report the case of a 54-year-old male patient who had CES following spinal surgery,with no obvious compression lesions found during re-exploration,suggesting that vascular insufficiency may have contributed to the ***,a series of urodynamic studies on bladder recovery patterns in such complications have also been *** Postoperative CES requires urgent imaging and exploration to rule out compression;noncompressive cases,including vascular insufficiency may performed conservative management.

关键词： Cauda equina syndrome Lumbar spine surgery Urinary retention Urodynamic study Postoperative complication Case report

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