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预制-装配式组合梁剪力群钉推出试验研究

科学技术与工程 2021年第23期21卷 9947-9953页

作者：蔡莉莉方金范亮西南交通建设集团股份有限公司昆明650599 重庆交通大学土木工程学院重庆400074

为揭示预制-装配式组合梁剪力群钉的破坏机制,通过开展一组3个试件的装配式剪力群钉推出破坏试验,研究了装配式剪力群钉的变形、滑移、裂缝发展以及栓钉破坏等典型破坏特征,并结合数值方法分析了栓钉与混凝土的相互作用关系。结果表明:... 详细信息

为揭示预制-装配式组合梁剪力群钉的破坏机制,通过开展一组3个试件的装配式剪力群钉推出破坏试验,研究了装配式剪力群钉的变形、滑移、裂缝发展以及栓钉破坏等典型破坏特征,并结合数值方法分析了栓钉与混凝土的相互作用关系。结果表明:加载全过程可分为两个阶段,线弹性阶段和塑性破坏阶段;试件均为延性破坏,最先出现预留孔四周界面裂缝,其次预制混凝土在预留孔下方角隅处45°向下开裂,最后栓钉全部或大部剪断;栓钉在弯剪共同作用下断裂;装配式剪力群钉中栓钉受力性能略弱于现浇群钉,建议采用规范计算时应适当折减,可取0.85装配折减系数。

关键词：桥梁工程试验研究装配式组合梁剪力键群钉承载力

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内圆磨床磨削砂轮的恒线速运行控制

煤矿机械 2007年第8期28卷 181-182页

作者：魏平俊蔡丽丽李钫中原工学院电子信息学院郑州450007 河南广播电视大学郑州450003 河南省建设总公司郑州450003

在内圆磨削的过程中,线速度随着磨削砂轮半径的减小而不断减小,导致磨削的精度和光洁度降低,磨削效率低。一般基于电机稳态等效方程的闭环控制很难实现恒线速运行控制。从电机的动态数学模型出发,提出了一个基于定子磁场定向的矢量控制... 详细信息

在内圆磨削的过程中,线速度随着磨削砂轮半径的减小而不断减小,导致磨削的精度和光洁度降低,磨削效率低。一般基于电机稳态等效方程的闭环控制很难实现恒线速运行控制。从电机的动态数学模型出发,提出了一个基于定子磁场定向的矢量控制恒线速运行控制方案。系统采用速度开环、磁链闭环的矢量控制方案。同时通过磁链调节器使定子磁链保持恒定,具有较好的动态性能以及较强的鲁棒性。

关键词：内圆磨床磨削恒线速磁场定向矢量控制

Preparation of silver nanoparticles through the reduction of straw-extracted lignin and its antibacterial hydrogel

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 504-514页

作者： Lou Zhang Shuo li Fu Tang Jingkai Zhang Yuetong Kang Hean Zhang lidong li State Key Laboratory for Advanced Metals and Materials School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China

Silver nanoparticles(Ag NPs)have attracted attention in the field of biomaterials due to their excellent antibacterial ***,the reducing and stabilizing agents used for the chemical reduction of Ag NPs are usually toxic and may cause water *** this work,Ag NPs(31.2 nm in diameter)were prepared using the extract of straw,an agricultural waste,as the reducing and stabilizing *** analysis revealed that the straw extract contained lignin,the structure of which possesses phenolic hydroxyl and methoxy groups that facilitate the reduction of silver salts into Ag *** surfaces of Ag NPs were negatively charged due to the encapsulation of a thin layer of lignin molecules that prevented their *** the prepared Ag NPs were added to the precursor solution of acrylamide,free radical polymerization was triggered without the need for extra heating or light irradiation,resulting in the rapid formation of an Ag NP-polyacrylamide composite *** inhibition zone test proved that the composite hydrogel possessed excellent antibacterial ability due to the presence of Ag *** prepared hydrogel may have potential applications in the fabrication of biomedical materials,such as antibacterial dressings.

关键词： silver nanoparticles hydrogel straw extraction antibacterial

Regulating crystallization and retarding oxidation in Sn-Pb perovskite via 1D cation engineering for high performance all-perovskite tandem solar cells

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Journal of Energy Chemistry 2025年第1期100卷 646-652页

作者： Ranran liu Xin Zheng Zaiwei Wang Miaomiao Zeng Chunxiang Lan Shaomin Yang Shangzhi li Awen Wang Min li Jing Guo Xuefei Weng Yaoguang Rong Xiong li Michael Gr?tzel Center for Mesoscopic Solar Cells Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Institute of Technology for Carbon Neutrality Shenzhen Institute of Advanced Technology Chinese Academy of Sciences School of Physics and Optoelectronic Engineering Hainan University Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO) Chinese Academy of Sciences School of Chemistry Chemical Engineering and Life Sciences State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology

All-perovskite tandem solar cells have the potential to surpass the theoretical efficiency limit of single junction solar cells by reducing thermalization ***,the challenges encompass the oxidation of Sn2+to Sn4+and uncontrolled crystallization kinetics in Sn-Pb perovskites,leading to nonradiative recombination and compositional heterogeneity to decrease photovoltaic efficiency and operational ***,we introduced an ionic liquid additive,1-ethyl-3-methylimidazolium iodide （EMIMI） into Sn-Pb perovskite precursor to form low-dimensional Sn-rich/pure-Sn perovskites at grain boundaries,which mitigates oxidation of Sn2+to Sn4+and regulates the film-forming dynamics of Sn/Pb-based perovskite *** optimized single-junction Sn-Pb perovskite devices incorporating EMIMI achieved a high efficiency of 22.87%.Furthermore,combined with wide-bandgap perovskite sub-cells in tandem device,we demonstrate 2-terminal all-perovskite tandem solar cells with a power conversion efficiency of 28.34%,achieving improved operational stability.

关键词： All-perovskite tandem solar cells Sn-Pb perovskite 1D Regulated crystallization Antioxidation

Perfluoropentane-based oxygen-loaded nanodroplets reduce microglial activation through metabolic reprogramming

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Neural Regeneration Research 2025年第4期20卷 1178-1191页

作者： Wanxian Luo Chuanhui Xu linxi li Yunxiang Ji Yezhong Wang Yingjia li Yongyi Ye Department of Medicine Ultrasonics Nanfang HospitalSouthern Medical UniversityGuangzhouGuangdong ProvinceChina Institute of Neuroscience Department of NeurosurgeryThe Second Affiliated Hospital of Guangzhou Medical UniversityGuangzhouGuangdong ProvinceChina

Microglia,the primary immune cells within the brain,have gained recognition as a promising therapeutic target for managing neurodegenerative diseases within the central nervous system,including Parkinson’s *** perfluorocarbon droplets have been reported to not only possess a high oxygen-carrying capacity,but also exhibit remarkable anti-inflammatory ***,the role of perfluoropentane in microglia-mediated central inflammatory reactions remains poorly *** this study,we developed perfluoropentane-based oxygen-loaded nanodroplets(PFP-OLNDs)and found that pretreatment with these droplets suppressed the lipopolysaccharide-induced activation of M1-type microglia in vitro and in vivo,and suppressed microglial activation in a mouse model of Parkinson’s *** suppression led to a reduction in the inflammatory response,oxidative stress,and cell migration capacity in ***,the neurotoxic effects were mitigated,which alleviated neuronal ***,ultrahigh-performance liquid chromatography–tandem mass spectrometry showed that the anti-inflammatory effects of PFP-OLNDs mainly resulted from the modulation of microglial metabolic *** further showed that PFP-OLNDs regulated microglial metabolic reprogramming through the AKT-mTOR-HIF-1α***,our findings suggest that the novel PFP-OLNDs constructed in this study alleviate microglia-mediated central inflammatory reactions through metabolic reprogramming.

关键词： metabolic reprogramming microglia microglial migration nanotherapy neurodegenerative diseases neuroinflammation oxygen-loaded nanodroplets Parkinson’s disease perfluoropentane ultra-performance liquid chromatography–mass spectrometry

Potential role and therapeutic implications of glutathione peroxidase 4 in the treatment of Alzheimer's disease

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Neural Regeneration Research 2025年第3期20卷 613-631页

作者： Yanxin Shen Guimei Zhang Chunxiao Wei Panpan Zhao Yongchun Wang Mingxi li li Sun Department of Neurology and Neuroscience Center The First Hospital of Jilin UniversityJilin UniversityChangchunJilin ProvinceChina Cognitive Impairment Center Department of NeurologyThe First Hospital of Jilin UniversityJilin UniversityChangchunJilin ProvinceChina

Alzheimer's disease is an age-related neurodegenerative disorder with a complex and incompletely understood pathogenesis. Despite extensive research, a cure for Alzheimer's disease has not yet been found. Oxidative stress mediates excessive oxidative responses, and its involvement in Alzheimer's disease pathogenesis as a primary or secondary pathological event is widely accepted. As a member of the selenium-containing antioxidant enzyme family, glutathione peroxidase 4 reduces esterified phospholipid hydroperoxides to maintain cellular redox homeostasis. With the discovery of ferroptosis, the central role of glutathione peroxidase 4 in anti-lipid peroxidation in several diseases, including Alzheimer's disease, has received widespread attention. Increasing evidence suggests that glutathione peroxidase 4 expression is inhibited in the Alzheimer's disease brain, resulting in oxidative stress, inflammation, ferroptosis, and apoptosis, which are closely associated with pathological damage in Alzheimer's disease. Several therapeutic approaches, such as small molecule drugs, natural plant products, and non-pharmacological treatments, ameliorate pathological damage and cognitive function in Alzheimer's disease by promoting glutathione peroxidase 4 expression and enhancing glutathione peroxidase 4 activity. Therefore, glutathione peroxidase 4 upregulation may be a promising strategy for the treatment of Alzheimer's disease. This review provides an overview of the gene structure, biological functions, and regulatory mechanisms of glutathione peroxidase 4, a discussion on the important role of glutathione peroxidase 4 in pathological events closely related to Alzheimer's disease, and a summary of the advances in small-molecule drugs, natural plant products, and non-pharmacological therapies targeting glutathione peroxidase 4 for the treatment of Alzheimer's disease. Most prior studies on this subject used animal models, and relevant clinical studies are lacking. Future clinica

关键词： apoptosis ferroptosis inflammation lipid peroxidation natural plant products neurodegenerative disorder neuroprotection oxidative stress small-molecule drugs

Sequence-activated chemiluminescence probes: programmable illumination for high-contrast in vivo sensing and imaging

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Science China Chemistry 2025年第1期68卷 26-34页

作者： Yutao Zhang Juan li Wei-Hong Zhu Zhiqian Guo Shanghai Key Laboratory of Functional Materials Chemistry Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Institute of Fine Chemicals School of Chemistry and Molecular Engineering East China University of Science and Technology State Key Laboratory of Bioreactor Engineering Shanghai Frontier Science Research Base of Optogenetic Techniques for Cell MetabolismEast China University of Science & Technology

Sequence-activated chemiluminescence(CL) technique offers a unique approach to detecting specific biomolecules or cellular events with high sensitivity and spatial resolution. The fundamental principle behind sequence-activated CL probes involves tailoring highly-controllable CL signals in response to specific sequences or events of interest, thus enabling high-contrast signals under complex physiological conditions. This sequential activation could be triggered by enzymes, reactive oxygen species(ROS), biothiols or changes in the microenvironment. These unique sequence-activated CL probes bestow several advantages, including minimal background, deep-tissue penetration, and the ability of non-invasive or minimally invasive detection. The sequence-activated CL techniques represent a significant advancement in molecular imaging and diagnostics. In this mini-review, we focus on the latest developments in sequential CL probes, addressing the technical challenges and discussing the future trajectory by harnessing CL signaling and molecular recognition.

关键词： chemiluminescnece sequence-activation in-vivo bioimaging cyclic peroxide

Thickness and sp3 bond modulation of（Ti/tetrahedral amorphous carbon）_n multilayer coatings

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Tungsten 2025年第1期7卷 152-160页

作者： Zhi-Jun Xie Jia-lin li ling Gong Xiang-li Zhong Hong-Jia Song Jin-Bin Wang National-Provincial Laboratory of Special Function Thin Film Materials School of Materials Science and Engineering Xiangtan University

The durability of wear-resistant tetrahedral amorphous carbon（ta-C） coatings is intimately linked to their thickness and the concentration of *** enhance the lifespan of the coatings,we have prepared a multilayer coating consisting of alternating layers of Ti and ta-C,denoted as（Ti/ta-C）_n,using arc ion plating.A multi-layer structure in conjunction with stage cooling is employed to enhance the thickness and promote *** results indicate that the ID/IGvalue,representing the ratio of the intensity of the D peak to that of the G peak in Raman spectroscopy,decreases from 0.85 when no stage cooling is applied to 0.35 when stage cooling is employed,suggesting an enhancement in the fraction of sp3bonds within the *** obtained（Ti/ta-C）_n multilayer coating without peeling off has a maximum thickness of 1.14 μm,which is almost double that of the ta-C coating single layer *** the same time,the coating has a low coefficient of friction,down to 0.069,and maintains excellent friction properties with a wear rate of 3.4×10-6mm3·N-1·*** results conclusively show that the preparation technology can enhance both thickness and sp3bonding in ta-C coatings,significantly expanding their utility across tools,molds,and precision engineering components.

关键词： Arc ion plating Multilayer structure sp3 bond Ta-C coating Wear resistance

氧化亚氮联合利多卡因行无痛人工流产术280例临床分析

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中国妇幼保健 2005年第4期20卷 449-450页

作者：蔡礼丽梁淑燕广东省东莞市茶山医院妇产科 523328

　目的: 探讨吸入 50%氧化亚氮 (N2O) 与 50%氧气 (O2 ) 的混合气体联合宫颈注射 2%利多卡因进行无痛人工流产术 (人流术) 的有效性和安全性。方法: 将人流术 580例分为A、B两组。其中A组 280例吸入 50%氧化亚氮 (N2O)与 50%氧气的混合... 详细信息

　目的: 探讨吸入 50%氧化亚氮 (N2O) 与 50%氧气 (O2 ) 的混合气体联合宫颈注射 2%利多卡因进行无痛人工流产术 (人流术) 的有效性和安全性。方法: 将人流术 580例分为A、B两组。其中A组 280例吸入 50%氧化亚氮 (N2O)与 50%氧气的混合气体联合宫颈注射 2%利多卡因进行无痛人流术, 称为联合组; B组 300例, 不用任何药物, 为对照组, 分析比较两组手术中镇痛效果, 宫口松弛情况, 手术出血量, 人流综合反应。结果: 联合组镇痛完全, 有效率达 97 5%。宫口完全松弛率 97 9%。两组比较有显著性差异 (P<0 05)。结论: 吸入氧化亚氮联合宫颈注射利多卡因进行无痛人流术, 镇痛效果确定, 人流时受术者意识处于朦胧状态, 安静, 无痛苦, 不良反应少, 苏醒快等。

关键词：氧化亚氮利多卡因镇痛人流综合反应