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史传文体之“作”与“修”的矛盾
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作者 汪春泓 《中山大学学报(社会科学版)》 CSSCI 北大核心 2024年第5期25-33,共9页
史传与诸子在《汉书·艺文志》中属于文献分类,而在《文心雕龙》里则属于文体分类,当然纪昀对此早就提出质疑。从文体论看,史传必须保持求真实和树大义的文体特点,以《春秋左氏传》为例,其间“《春秋》大义”与“因鲁史”就构成孔... 史传与诸子在《汉书·艺文志》中属于文献分类,而在《文心雕龙》里则属于文体分类,当然纪昀对此早就提出质疑。从文体论看,史传必须保持求真实和树大义的文体特点,以《春秋左氏传》为例,其间“《春秋》大义”与“因鲁史”就构成孔子之《春秋》的文体应有之标准,即使实录也离不开善恶是非等大义之表达,若《春秋》无大义,则一部《春秋》将黯淡无光。因而衍生出历史上存在的孔子“作《春秋》”与“修《春秋》”两种不同叙事,从经学和史学两个角度辨析其所指。从史传文体特征而论,一方面孔子作《春秋》,凸显其当一部大法的原创性价值;另一方面孔子修《春秋》却是兼顾史家思想和史料的最佳结合,以至于达到游夏之徒不能赞一辞的绝对高度。然而,从孔子到左丘明以降,以至《史记》《汉书》,史家和史料之因缘际会,却都存在着因人而异性,或不确定性,因而由宋儒请传统《春秋》学走下神坛。于是《史记》《汉书》等史书,因其人为作品之性质,显示了史家、史料诸端局限性的史学困境,这也正是史传文体所遭遇永恒的矛盾和困惑。 展开更多
关键词 “作” “修” 《春秋》大义 文献分类 文体分类
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清代广州瑞典商馆:1732—1856年
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作者 汤开建 李嘉昌 《暨南学报(哲学社会科学版)》 北大核心 2025年第2期34-54,共21页
瑞典商馆是广州十三行街夷馆区中设立较早的外国商馆之一,为瑞典东印度公司商人来广州经营贸易时租居的行馆,位于广州夷馆区中段,其中文馆名为修和行,又称喘行、瑞行,曾经过多次改造和修建。早期的瑞典商馆是一座完全的中式建筑,1768年... 瑞典商馆是广州十三行街夷馆区中设立较早的外国商馆之一,为瑞典东印度公司商人来广州经营贸易时租居的行馆,位于广州夷馆区中段,其中文馆名为修和行,又称喘行、瑞行,曾经过多次改造和修建。早期的瑞典商馆是一座完全的中式建筑,1768年经过重修,廊柱和门窗明显都呈西式风格,成为一座完全西式的建筑物。自1805年瑞典东印度公司停止直航广州的贸易后,除留有几名瑞典领事居住外,瑞典商馆主要归美国商人使用。在1822年西关大火后,瑞典商馆被重建,商馆的装饰更加精致。1856年,广州夷馆区被大火烧毁,瑞典商馆就此湮灭。 展开更多
关键词 清代 瑞典商馆 瑞行 和行 广州 十三行 夷馆区
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矿浆固相浓度、粒度对LIBS测量信号的影响规律及表征方法研究
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作者 于桐 于洪霞 +2 位作者 张鹏 孙兰香 陈彤 《光谱学与光谱分析》 北大核心 2025年第5期1334-1340,共7页
激光诱导击穿光谱技术可以直接对矿浆进行在线分析,但由于矿浆基质成分十分复杂,固体颗粒浓度和粒度的变化都会对光谱信号产生影响,使得光谱信号与矿物化学成分之间的关系复杂难以表征。因此,研究矿浆固相浓度、粒度对光谱信号的影响机... 激光诱导击穿光谱技术可以直接对矿浆进行在线分析,但由于矿浆基质成分十分复杂,固体颗粒浓度和粒度的变化都会对光谱信号产生影响,使得光谱信号与矿物化学成分之间的关系复杂难以表征。因此,研究矿浆固相浓度、粒度对光谱信号的影响机制十分重要。为此,使用多种粒度的SiO_(2)粉末与不同质量的水进行配比,得到不同固相浓度、粒度的模拟矿浆样本,并进行LIBS光谱信号采集与数据分析,系统的研究了矿浆固相浓度、粒度对固相和液相中包含元素的特征谱线强度的影响。首先,使用皮尔森相关系数量化评估固相浓度、粒度对LIBS光谱信号的影响。结果显示:在同一固相粒度下,固相浓度与全谱和值及各元素的特征谱线强度之间的相关系数大多高于0.9,说明整体光谱强度随固相浓度的升高而增强;在同一固相浓度下,固相粒度主成分与硅元素特征谱线强度之间的相关系数在0.99左右,说明固相颗粒中元素特征谱线随固相颗粒的增大而减弱。进一步建立了矿浆固相浓度、粒度同步变化时光谱强度与固相浓度、粒度的关系模型,通过模型的拟合优度(R^(2))来分析固相浓度、粒度对LIBS光谱的影响。结果显示:只有硅元素特征谱线强度的固相粒度表征模型的拟合优度可以达到0.9以上,说明单一的固相浓度或粒度无法完全准确地反映样本中各元素特征谱线强度的变化情况;固相浓度、粒度共同表征光谱强度的模型,各元素特征谱线的拟合优度均超过0.9,说明固相浓度和粒度对各元素特征谱线强度的影响是耦合存在的,需要融合多源信息进行综合表征。这些结果为进一步研究基于多源信息融合的LIBS光谱稳定性与定量分析准确性的提升,提供了系统的分析基础。 展开更多
关键词 激光诱导击穿光谱 矿浆 在线分析 固相浓度 固相粒度
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ESCRT Mechanism-mediated Repair of Plasma Membrane Damage Induced by Regulatory Cell Death
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作者 FENG Tian-Yang DENG Le +2 位作者 XU Gou LI Li GUO Miao-Miao 《生物化学与生物物理进展》 北大核心 2025年第5期1099-1112,共14页
The plasma membrane(PM)plays an essential role in maintaining cell homeostasis,therefore,timely and effective repair of damage caused by factors such as mechanical rupture,pore-forming toxins,or pore-forming proteins ... The plasma membrane(PM)plays an essential role in maintaining cell homeostasis,therefore,timely and effective repair of damage caused by factors such as mechanical rupture,pore-forming toxins,or pore-forming proteins is crucial for cell survival.PM damage induces membrane rupture and stimulates an immune response.However,damage resulting from regulated cell death processes,including pyroptosis,ferroptosis,and necroptosis,cannot be repaired by simple sealing mechanisms and thus,requires specialized repair machinery.Recent research has identified a PM repair mechanism of regulated cell death-related injury,mediated by the endosomal sorting complexes required for transport(ESCRT)machinery.Here,we review recent progress in elucidating the ESCRT machinery-mediated repair mechanism of PM injury,with particular focus on processes related to regulated cell death.This overview,along with continued research in this field,may provide novel insights into therapeutic targets for diseases associated with dysregulation of regulated cell death pathways. 展开更多
关键词 ESCRT PYROPTOSIS ferroptosis NECROPTOSIS plasma membrane repair
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Evaluation of restoration effects for city walls based on terahertz-infrared integrated technology
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作者 MENG Tian-hua ZHAO Guo-zhong +3 位作者 XU Shi-xiang ZHANG Hai-jiao LI Bang-quan HU Wei-dong 《中国光学(中英文)》 北大核心 2025年第4期954-967,共14页
To scientifically evaluate the restoration performance of ancient city walls,Terahertz time-domain spectroscopy(THz-TDS)and infrared thermal imaging technology were applied to assess the Desheng Fortress(Ming Dynasty)... To scientifically evaluate the restoration performance of ancient city walls,Terahertz time-domain spectroscopy(THz-TDS)and infrared thermal imaging technology were applied to assess the Desheng Fortress(Ming Dynasty).Three representative sections were examined:adobe brick masonry repaired(Area 1),well-preserved original(Area 2),and layer-by-layer ramming repaired(Area 3).THz spectral data revealed significant differences between Area 1(time delay:3.72 ps;refractive index:2.224)and Area 2(time delay:3.02 ps;refractive index:2.107),while Area 3(time delay:3.12 ps;refractive index:2.098)demonstrated nearly identical THz spectral data to Area 2.Infrared thermal imaging also showed that the Area 3 restored by layer-by-layer ramming exhibited greater uniformity with fewer instances of cracks,capillary phenomena,or biological diseases.The proposed point-surface integrated evaluation methodology synergistically combines infrared thermography mapping of heritage surfaces with THz spectral datasets acquired through in-situ micro-sampling,enabling quantitative restoration assessment and providing a novel approach for scientifically validating traditional conservation techniques. 展开更多
关键词 nondestructive testing cultural relic restoration performance evaluation high sensitivity
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Dual-ligand-modified copper nanoclusters:Synthesis and application in ornidazole detection
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作者 TIAN Rui LI Duo +4 位作者 REN Yuan CHAI Jiamin SUN Xuehua LI Haoyu ZHANG Yuecheng 《无机化学学报》 北大核心 2025年第6期1245-1255,共11页
Bovine serum albumin(BSA)and glycine(Gly)dual-ligand-modified copper nanoclusters(BSA-Gly CuNCs)with high fluorescence intensity were synthesized by a one-pot strategy.Based on the competitive fluorescence quenching a... Bovine serum albumin(BSA)and glycine(Gly)dual-ligand-modified copper nanoclusters(BSA-Gly CuNCs)with high fluorescence intensity were synthesized by a one-pot strategy.Based on the competitive fluorescence quenching and dynamic quenching effects of ornidazole(ONZ)on BSA-Gly CuNCs,a simple and sensitive detection method for ONZ was successfully developed.The experimental results demonstrate that the addition of the small molecule Gly can more effectively protect CuNCs,and thus enhance its fluorescence intensity and stability.The proposed assay allowed for the detection of ONZ in a linear range of 0.28 to 52.60μmol·L^(-1)and a detection limit of 0.069μmol·L^(-1).Compared with the single-ligand-modified CuNCs,dual-ligand-modified BSA-Gly CuNCs had higher fluorescence intensity,stability,and sensing ability and were successfully applied to evaluate ONZ in actual ONZ tablets. 展开更多
关键词 copper nanocluster ORNIDAZOLE dual-ligand-modified fluorescence detection
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Improving the oxidation resistance of HfB_(2)-SiC coatings on carbon/carbon composites by CeO_(2) doping
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作者 HE Chang-lin SHANG Zhi-chao +10 位作者 WANG Wei-guang LI Xiang-ming WANG Kun CHEN Yue-xing BAI Xin-tan WANG Pei-pei JI Xiang REN Xuan-ru Evgeny A Levashov Ph V Kiryukhantsev-Korneev FENG Pei-zhong 《新型炭材料(中英文)》 北大核心 2025年第3期688-702,共15页
To improve the oxidation resistance of HfB_(2)-SiC coatings on carbon/carbon composites at 1700°C in air,CeO_(2) was introduced to improve oxygen blocking and its mechanism was investigated.During the rapid oxida... To improve the oxidation resistance of HfB_(2)-SiC coatings on carbon/carbon composites at 1700°C in air,CeO_(2) was introduced to improve oxygen blocking and its mechanism was investigated.During the rapid oxidation stage,CeO_(2) accelerated the formation of a multiphase glass layer on the coating surface.The maximum oxidation rates of CeO_(2)-HfB2-SiC coatings with 1%,3%,and 5%CeO_(2) were 24.1%,20.3%,and 53.2%higher than that of the unmodified HfB2-SiC coating,respectively.In the stable oxidation stage,the maximum oxidation rates of coatings with 1%and 3%CeO_(2) decreased by 31.4%and 21.9%,respectively,demonstrating adequate inert protection.CeO_(2) is a“coagulant”and“stabilizer”in the composite glass layer.However,increasing the CeO_(2) content accelerates the reaction between the SiO_(2) glass phase and SiC,leading to a higher SiO_(2) consumption and reduced self-healing ability of the glass layer.The 1%CeO_(2)-60%HfB2-39%SiC coating showed improved glass layer viscosity and stability,moderate SiO_(2) consumption,and better self-healing ability,significantly boosting the oxidation protection of the coating. 展开更多
关键词 HfB_(2)-SiC coatings CeO_(2) Oxidation resistance Self-healing ability MECHANISM
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Dual-surface capped hydroxyapatite nano-amendment with tuned alternate long-short chain configuration for efficient adsorption towards multi-heavy metal ions in complex-contaminated systems
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作者 GAO Mochou MENG Shan +7 位作者 ZHANG Jinzhong FENG Wenhua DONG Shuo CHEN Jianping ZHAO Yanbao YU Laigui YING Rongrong ZOU Xueyan 《无机化学学报》 北大核心 2025年第7期1427-1438,共12页
Hydroxyapatite nanoparticles(HAP NPs)were synthesized by a one‐step hydrothermal method.The surface of HAP NPs was grafted-SH and-COOH chelating groups via in situ surface‐modification with iminodiacetic acid(IDA)an... Hydroxyapatite nanoparticles(HAP NPs)were synthesized by a one‐step hydrothermal method.The surface of HAP NPs was grafted-SH and-COOH chelating groups via in situ surface‐modification with iminodiacetic acid(IDA)and 3‐mercaptopropyl trimethoxysilane(MPS)to afford dual surface‐capped nano‐amendment HAPIDA/MPS.The structure of HAP‐IDA/MPS was characterized,and its adsorption performance for Hg^(2+),Cu^(2+),Zn^(2+),Ni^(2+),Co^(2+),and Cd^(2+)was evaluated.The total adsorption capacity of 0.10 g HAP‐IDA/MPS nano‐amendment for Hg^(2+),Cu^(2+),Zn^(2+),Ni^(2+),Co^(2+),and Cd^(2+)with an initial mass concentration of 20 mg·L^(-1) reached 13.7 mg·g^(-1),about 4.3 times as much as that of HAP.Notably,HAP‐IDA/MPS nano‐amendment displayed the highest immobilization rate for Hg^(2+),possibly because of its chemical reaction with-SH to form sulfide,possessing the lowest solubility product constant among a variety of metal sulfides. 展开更多
关键词 heavy metal HYDROXYAPATITE nano-amendment configuration tuning synergistic adsorption
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Occurrence of“Hippotherium”in the Old World:a revision of two hipparion species in Eurasia
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作者 SUN Bo-Yang LIU Yan +1 位作者 WANG Shi-Qi DENG Tao 《古脊椎动物学报(中英文)》 北大核心 2025年第1期57-80,共24页
A controversial taxon,Hipparion plocodus,is reviewed in the present study.Hi.plocodus has been confirmed to be a valid species with definite diagnostic characteristics,represented by cranial specimens from Baode,Shanx... A controversial taxon,Hipparion plocodus,is reviewed in the present study.Hi.plocodus has been confirmed to be a valid species with definite diagnostic characteristics,represented by cranial specimens from Baode,Shanxi Province.The phylogenetic analysis performed in the present study,with a new matrix,shows that Hi.plocodus forms a monophyletic group with a European species,Hippotherium malpassii.Actually,no close relationship between so-called Hm.malpassii and the genus Hippotherium has been identified,and the record of stratigraphic range of this genus in late stage of Late Miocene is currently absent.Herein previously Hi.plocodus and Hm.malpassii have both attributed into“Hipparion”before the discovery of better material.Evolutionary stages and correlative absolute age showed that these two species should derive independently from some primitive clade.During the late stage of the Late Miocene,the development of the Asian summer monsoon enhanced the humidity of China,with forest and wood habitats expanding considerably under this setting.As the result,one Eurasian closed-habitat lineage thus extended its range into China,which had become very suited for it,give rise to“Hi.”plocodus. 展开更多
关键词 Eurasian hipparion systematic revision PHYLOGENY paleozoogeography
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基于三维模型匹配的飞机位姿参数测量技术
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作者 马晓东 景慧莹 《中国测试》 北大核心 2025年第4期168-176,共9页
针对近场及起飞着陆过程飞机位姿参数的动态测量需求,提出一种基于先验三维模型匹配的飞机位姿参数视觉测量方法。利用搭载多波段可变焦成像基元的智能光电跟踪测量系统,实现全天时复杂气候条件下目标大范围跟踪与成像,采用基于空间参... 针对近场及起飞着陆过程飞机位姿参数的动态测量需求,提出一种基于先验三维模型匹配的飞机位姿参数视觉测量方法。利用搭载多波段可变焦成像基元的智能光电跟踪测量系统,实现全天时复杂气候条件下目标大范围跟踪与成像,采用基于空间参考点不确定性的相对位姿求解算法获取目标的初始位姿参数;之后,结合目标飞机先验三维CAD模型进行空间在线投影配准,以最小化分割损失和稠密特征匹配损失为条件进行迭代优化,获取目标飞机位姿的最优测量值。以实际C919飞行数据进行试验验证,结果表明所提出方法位置测量RMS误差优于1.2 m,姿态测量RMS误差优于0.3°,满足实际试飞测量需求。 展开更多
关键词 飞机位姿参数 三维模型匹配 投影配准 分割损失 稠密特征损失
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Deformations and extensions of modified λ-differential Lie-Yamaguti algebras
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作者 TENG Wen PAN Yuewei 《中山大学学报(自然科学版)(中英文)》 北大核心 2025年第4期115-127,共13页
The modifiedλ-differential Lie-Yamaguti algebras are considered,in which a modifiedλ-differential Lie-Yamaguti algebra consisting of a Lie-Yamaguti algebra and a modifiedλ-differential operator.First we introduce t... The modifiedλ-differential Lie-Yamaguti algebras are considered,in which a modifiedλ-differential Lie-Yamaguti algebra consisting of a Lie-Yamaguti algebra and a modifiedλ-differential operator.First we introduce the representation of modifiedλ-differential Lie-Yamaguti algebras.Furthermore,we establish the cohomology of a modifiedλ-differential Lie-Yamaguti algebra with coefficients in a representation.Finally,we investigate the one-parameter formal deformations and Abelian extensions of modifiedλ-differential Lie-Yamaguti algebras using the second cohomology group. 展开更多
关键词 Lie-Yamaguti algebra modifiedλ-differential operator representation and cohomology one-parameter formal deformation Abelian extension
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Controlling the conductivity and microporosity of biocarbon to produce supercapacitors with battery-level energies at an ultrahigh power
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作者 CHENG Bei XIE Xing-yan +5 位作者 WAN Liu CHEN Jian ZHANG Yan DU Cheng GUO Xue-feng XIE Ming-jiang 《新型炭材料(中英文)》 北大核心 2025年第2期409-420,共12页
In order to meet the demands of new-generation electric vehicles that require high power output(over 15 kW/kg),it is crucial to increase the energy density of car-bon-based supercapacitors to a level comparable to tha... In order to meet the demands of new-generation electric vehicles that require high power output(over 15 kW/kg),it is crucial to increase the energy density of car-bon-based supercapacitors to a level comparable to that of batteries,while maintaining a high power density.We re-port a porous carbon material produced by immersing pop-lar wood(PW)sawdust in a solution of KOH and graphene oxide(GO),followed by carbonization.The resulting mater-ial has exceptional properties as an electrode for high-en-ergy supercapacitors.Compared to the material prepared by the direct carbonization of PW,its electrical conductivity was in-creased from 0.36 to 26.3 S/cm.Because of this and a high microporosity of over 80%,which provides fast electron channels and a large ion storage surface,when used as the electrodes for a symmetric supercapacitor,it gave a high energy density of 27.9 Wh/kg@0.95 kW/kg in an aqueous electrolyte of 1.0 mol/L Na_(2)SO_(4).The device also had battery-level energy storage with maximum energy densities of 73.9 Wh/kg@2.0 kW/kg and 67.6 Wh/kg@40 kW/kg,an ultrahigh power density,in an organic electrolyte of 1.0 mol/L TEABF4/AN.These values are comparable to those of 30−45 Wh/kg for Pb-acid batteries and 30−55 Wh/kg for aqueous lithium batteries.This work indicates a way to prepare carbon materials that can be used in supercapacit-ors with ultrahigh energy and power densities. 展开更多
关键词 Reduced GO modification Loose wood Symmetric supercapacitor Battery-level energy density
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Optimization of mesh characteristics of gear pair considering influence of assembly errors
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作者 ZHAO Xiao-jian MA Hui +5 位作者 MA Ze-yu LIU Jia-qi CAO Peng WU Yu-ping DING Xiang-fu ZHAO Tian-yu 《Journal of Central South University》 2025年第4期1400-1430,共31页
Gear assembly errors can lead to the increase of vibration and noise of the system,which affect the stability of system.The influence can be compensated by tooth modification.Firstly,an improved three-dimensional load... Gear assembly errors can lead to the increase of vibration and noise of the system,which affect the stability of system.The influence can be compensated by tooth modification.Firstly,an improved three-dimensional loaded tooth contact analysis(3D-LTCA)method which can consider tooth modification and coupling assembly errors is proposed,and mesh stiffness calculated by proposed method is verified by MASTA software.Secondly,based on neural network,the surrogate model(SM)that maps the relationship between modification parameters and mesh mechanical parameters is established,and its accuracy is verified.Finally,SM is introduced to establish an optimization model with the target of minimizing mesh stiffness variations and obtaining more even load distribution on mesh surface.The results show that even considering training time,the efficiency of gear pair optimization by surrogate model is still much higher than that by LTCA method.After optimization,the mesh stiffness fluctuation of gear pair with coupling assembly error is reduced by 34.10%,and difference in average contact stresses between left and right regions of the mesh surface is reduced by 62.84%. 展开更多
关键词 helical gear mesh characteristics gear tooth modification assembly errors neural network multi-objective optimization
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Gear flank modification and precision control based on electronic gearbox
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作者 TIAN Xiao-qing LU Yi-guo +5 位作者 YOU Tong-fei TANG Jian-ping RUI Xiao-yu LI Guang-hui XIA Lian HAN Jiang 《Journal of Central South University》 2025年第2期509-522,共14页
Gear flank modification is essential to reduce the noise generated in the gear meshing process,improve the gear transmission performance,and reduce the meshing impact.Aiming at the problem of solving the additional mo... Gear flank modification is essential to reduce the noise generated in the gear meshing process,improve the gear transmission performance,and reduce the meshing impact.Aiming at the problem of solving the additional motions of each axis in the higher-order topology modification technique and how to accurately add the different movements expressed in the form of higher-order polynomials to the corresponding motion axes of the machine tool,a flexible higher-order gear topology modification technique based on an electronic gearbox is proposed.Firstly,a two-parameter topology gear surface equation and a grinding model of wheel grinding gears are established,and the axial feed and tangential feed are expressed in a fifth-order polynomial formula.Secondly,the polynomial coefficients are solved according to the characteristics of the point contact when grinding gears.Finally,an improved electronic gearbox model is constructed by combining the polynomial interpolation function to achieve gear topology modification.The validity and feasibility of the modification method based on the electronic gearbox are verified by experimental examples,which is of great significance for the machining of modification gears based on the continuous generative grinding method of the worm grinding wheel. 展开更多
关键词 gear grinding topological modification polynomial interpolation electronic gearbox grinding model
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Optimized joint repair effects on damage evolution and arching mechanism of CRTS II slab track under extreme thermal conditions
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作者 CAI Xiao-pei CHEN Ze-lin +3 位作者 CHEN Bo-jing ZHONG Yang-long ZHOU Rui HUANG Yi-chen 《Journal of Central South University》 2025年第6期2273-2287,共15页
To address the issue of extreme thermal-induced arching in CRTS II slab tracks due to joint damage,an optimized joint repair model was proposed.First,the formula for calculating the safe temperature rise of the track ... To address the issue of extreme thermal-induced arching in CRTS II slab tracks due to joint damage,an optimized joint repair model was proposed.First,the formula for calculating the safe temperature rise of the track was derived based on the principle of stationary potential energy.Considering interlayer evolution and structural crack propagation,an optimized joint repair model for the track was established and validated.Subsequently,the impact of joint repair on track damage and arch stability under extreme temperatures was studied,and a comprehensive evaluation of the feasibility of joint repair and the evolution of damage after repair was conducted.The results show that after the joint repair,the temperature rise of the initial damage of the track structure can be increased by 11℃.Under the most unfavorable heating load with a superimposed temperature gradient,the maximum stiffness degradation index SDEG in the track structure is reduced by about 81.16%following joint repair.The joint repair process could effectively reduce the deformation of the slab arching under high temperatures,resulting in a reduction of 93.96%in upward arching deformation.After repair,with the damage to interfacing shear strength,the track arch increases by 2.616 mm. 展开更多
关键词 CRTS II slab track optimized joint repair arching mechanism temperature load damage initiation and evolution
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基于相干信号源的修正ISM算法 被引量:2
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作者 赵曦 侯朋 刘文帅 《舰船科学技术》 北大核心 2014年第11期153-156,161,共5页
介绍一种基于相干信号源的修正ISM算法(MISM)。该算法采用CBF常规波束形成算法及MVDR波束形成算法、MUSIC算法进行处理并给出公式。结合3种算法各自的优势,通过对接收数据阵进行去相关处理,突破了ISM算法只能对相干信号源进行方位估计... 介绍一种基于相干信号源的修正ISM算法(MISM)。该算法采用CBF常规波束形成算法及MVDR波束形成算法、MUSIC算法进行处理并给出公式。结合3种算法各自的优势,通过对接收数据阵进行去相关处理,突破了ISM算法只能对相干信号源进行方位估计的局限性。通过计算机仿真进行3种算法的对比分析,验证该算法的有效性。 展开更多
关键词 相干信号源 宽带 高分辨 DOA估计
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Development and progress in polymer materials foranti-corrosion and anti-fouling applications:A review 被引量:1
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作者 LYU Ren-jiang WANG Nan +5 位作者 ZHANG Rui-yong GAO Guang-tao LI Sheng-xi DUAN Ji-zhou HOU Bao-rong SAND Wolfgang 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第10期3547-3569,共23页
Corrosion has always been a difficult problem that troubles and restricts the application and development ofengineering materials.By endowing coatings on metal surfaces with polymer material,it is possible to protect ... Corrosion has always been a difficult problem that troubles and restricts the application and development ofengineering materials.By endowing coatings on metal surfaces with polymer material,it is possible to protect othermaterials from factors including acid and alkali,water vapor,bacteria.Therefore,it is necessary to summarize theresearch progress of polymer materials in the field of pollution and corrosion prevention in recent years.This articlesummarizes four types of polymer materials with good weather resistance:polyurethane(PU),polydimethylsiloxane(PDMS),polyvinylidene fluoride(PVDF),and polyvinylidene chloride(PVDC).These four polymer materials aresuitable for making polymer anti-corrosion or anti-fouling materials and each has its own characteristics.PU can firmlyadhere to various substrates,effectively protecting and extending their lifespan,but the environmentally friendly varietiescurrently used,namely water-borne polyurethanes(WPU),generally have poor mechanical properties.PDMS is nontoxicand has excellent hydrophobicity,but its static anti-fouling ability is insufficient when applied in the field of antifouling.PVDF has good chemical resistance and high mechanical properties,good UV resistance making it suitable foroutdoor use like in the marine environment.However,PVDF lacks flexibility after molding and its manufacturing cost isrelatively high.PVDC has excellent water vapor barrier properties,but poor adhesion to metal material surfaces.Therefore,researchers need to modify these four polymers when using them to solve the problem of corrosion orbiofouling.The article will review the research progress of four types of polymers in recent years from the perspectivesof anti-corrosion,anti-fouling,and a strategy named as self-healing that is beneficial for protecting polymer surfacesfrom mechanical damage,and summarize the modification methods adopted by researchers when applying thesematerials.Finally,a summary of the application and the prospects of these polymer materials are presented. 展开更多
关键词 ANTI-CORROSION POLYMER corrosion ANTI-FOULING SELF-HEALING
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Photothermal self-healing polyurethane coating based on hollow nanofillers in seawater
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作者 KANG Qian-qian MAO Zhi-peng +3 位作者 PENG Li-ming MYRONYUK Oleksiy LI Wei-hua WANG Wei 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第10期3447-3462,共16页
Herein,a novel composite coating with excellent self-healing and corrosion resistance activated byphotothermal responsive hollow core-shell nanofillers was developed.A photothermal nanofiller(Co_(9)S_(8)@Bi_(2)S_(3))w... Herein,a novel composite coating with excellent self-healing and corrosion resistance activated byphotothermal responsive hollow core-shell nanofillers was developed.A photothermal nanofiller(Co_(9)S_(8)@Bi_(2)S_(3))with ahollow core-shell structure was synthesized and then added to polyurethane(PU)to prepare PU-Co_(9)S_(8)@Bi_(2)S_(3)compositecoating.Applying 808 nm near-infrared irradiation induces a photothermal effect in Co_(9)S_(8)@Bi_(2)S_(3),which subsequentlyinitiates the reconstruction of reversible hydrogen bonds,facilitating the self-healing of coating scratches.The excellentphotothermal self-healing performance of PU-Co_(9)S_(8)@Bi_(2)S_(3)coating was demonstrated by scratch tests and moleculardynamics simulations.The electrochemical impedance spectroscopy test results showed that the PU-Co_(9)S_(8)@Bi_(2)S_(3)coating has good self-healing and anti-corrosion properties.The low-frequency impedance modulus of the coating afterthree self-healing sessions was still close to 109Ω·cm^(2)after 30 d of immersion in seawater.This study provides a newstrategy for developing multi-cycle self-healing coatings triggered by photothermal effects. 展开更多
关键词 polyurethane coating photothermal effect SELF-HEALING corrosion protection
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Preparation of alkaline-responsive nano-electrospinning and anticorrosion properties of self-healing coating
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作者 JI Wen-hui CAO Lin +6 位作者 JI Xiao-hong PENG Li-ming MYRONYUK Oleksiy HAN Dong-xiao PEI Yan-tong LI Wei-hua WANG Wei 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第10期3463-3481,共19页
In this paper,1-butyl-3-methylimidazole tetrafluoroborate([BMIM]BF4)is used as corrosion inhibitor.Polyacrylonitrile(PAN)is used to load the corrosion inhibitor.PAN/[BMIM]BF4 hybrid nanofibers are successfullysynthesi... In this paper,1-butyl-3-methylimidazole tetrafluoroborate([BMIM]BF4)is used as corrosion inhibitor.Polyacrylonitrile(PAN)is used to load the corrosion inhibitor.PAN/[BMIM]BF4 hybrid nanofibers are successfullysynthesized by electrospinning technology.The alkyd varnish is coated on the fiber membrane to prepare a compositecoating,and then a series of tests are carried out on the self-healing and anticorrosive performance of the compositecoating.It is observed by scanning electron microscope that the fiber morphology is stable and there is no bead-likestructure.The composition of the composite fiber is analyzed by Fourier infrared spectroscopy,and it is confirmed thatthe hybrid nanofiber was successfully prepared.3D laser confocal scanning microscope was used to observe thecorrosion morphology and profile of the carbon steel.The composite coating shows good self-healing performance.[BMIM]BF4 can form a protective film on the surface of the bare carbon steel substrate through physical adsorption orchemical adsorption in an alkaline environment.Electrochemical impedance spectroscopy was tested and analyzed.It isfound that the maximum corrosion inhibition efficiency of the coating is 88.5%in 3.5 wt.%alkaline NaCl solution.Compared with the blank coating without nanofibers,the composite fiber varnish composite coating exhibits good selfhealingand anti-corrosion properties. 展开更多
关键词 ELECTROSPINNING self-healing coating alkaline-responsive corrosion protection
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m^(6)A modification of lncRNA in middle ear cholesteatoma
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作者 HE Jun XIE Shumin +3 位作者 JIN Li FU Jinfeng YUAN Qiulin LIU Wei 《中南大学学报(医学版)》 CAS CSCD 北大核心 2024年第5期667-678,共12页
Objective:Middle ear cholesteatoma is a non-tumorous condition that typically leads to hearing loss,bone destruction,and other severe complications.Despite surgery being the primary treatment,the recurrence rate remai... Objective:Middle ear cholesteatoma is a non-tumorous condition that typically leads to hearing loss,bone destruction,and other severe complications.Despite surgery being the primary treatment,the recurrence rate remains high.Therefore,exploring the molecular mechanisms underlying cholesteatoma is crucial for discovering new therapeutic approaches.This study aims to explore the involvement of N6-methyladenosine(m^(6)A)methylation in long non-coding RNAs(lncRNAs)in the biological functions and related pathways of middle ear cholesteatoma.Methods:The m^(6)A modification patterns of lncRNA in middle ear cholesteatoma tissues(n=5)and normal post-auricular skin tissues(n=5)were analyzed using an lncRNA m^(6)A transcriptome microarray.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analyses were conducted to identify potential biological functions and signaling pathways involved in the pathogenesis of middle ear cholesteatoma.Methylated RNA immunoprecipitation(MeRIP)-PCR was used to validate the m^(6)A modifications in cholesteatoma and normal skin tissues.Results:Compared with normal skin tissues,1525 lncRNAs were differentially methylated in middle ear cholesteatoma tissues,with 1048 showing hypermethylation and 477 showing hypomethylation[fold change(FC)≥3 or<1/3,P<0.05].GO enrichment analysis indicated that hypermethylated lncRNAs were involved in protein phosphatase inhibitor activity,neuron-neuron synapse,and regulation ofα-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid(AMPA)receptor activity.Hypomethylated lncRNAs were associated with mRNA methyltransferase activity,secretory granule membrane,and mRNA methylation.KEGG analysis revealed that hypermethylated lncRNAs were mainly associated with 5 pathways:the Hedgehog signaling pathway,viral protein interaction with cytokines and cytokine receptors,mitogen-activated protein kinase(MAPK)signaling pathway,cytokine-cytokine receptor interaction,and adrenergic signaling in cardiomyocytes.Hypomethylated lncRNAs were mainly involved in 4 pathways:Renal cell carcinoma,tumor necrosis factor signaling pathway,transcriptional misregulation in cancer,and cytokine-cytokine receptor interaction.Additionally,MeRIP-PCR confirmed the changes in m^(6)A methylation levels in NR_033339,NR_122111,NR_130744,and NR_026800,consistent with microarray analysis.Real-time PCR also confirmed the significant upregulation of MAPK1 and NF-κB,key genes in the MAPK signaling pathway.Conclusion:This study reveals the m^(6)A modification patterns of lncRNAs in middle ear cholesteatoma,suggests a direction for further research into the role of lncRNA m^(6)A modification in the etiology of cholesteatoma.The findings provide potential therapeutic targets for the treatment of middle ear cholesteatoma. 展开更多
关键词 long non-coding RNA m6A modifications middle ear cholesteatoma
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