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Discovery of a Novel Ginseng Polysaccharide:Structure Characterization,in vitro Fermentability and Anti-oxidative Mechanism of Fermented Product via the Nrf2/HO-1 Pathway on Aβ-induced-PC 12 Cells
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作者 DONG Binbin HOU Zong +3 位作者 ZHENG Zhong XING Junpeng LIU Zhiqiang LIU Shu 《高等学校化学学报》 北大核心 2026年第1期173-189,共17页
In this study,a novel polysaccharide GPA-G 2-H was derived from ginseng.Furthermore,the coherent study of its structural characteristics,fermented characteristics in vitro,as well as antioxidant mechanism of fermented... In this study,a novel polysaccharide GPA-G 2-H was derived from ginseng.Furthermore,the coherent study of its structural characteristics,fermented characteristics in vitro,as well as antioxidant mechanism of fermented product FGPA-G 2-H on Aβ25-35-induced PC 12 cells were explored.The structure of GPA-G 2-H was determined by means of zeta potential analysis,FTIR,HPLC,XRD,GC-MS and NMR.The backbone of GPA-G 2-H was mainly composed of→4)-α-D-Glcp-(1→with branches substituted at O-3.Notably,GPA-G 2-H was degraded by intestinal microbiota in vitro with total sugar content and pH value decreasing,and short-chain fatty acids(SCFAs)increasing.Moreover,GPA-G 2-H significantly promoted the proliferation of Lactobacillus,Muribaculaceae and Weissella,thereby making positive alterations in intestinal microbiota composition.Additionally,FGPA-G 2-H activated the Nrf 2/HO-1 signaling pathway,enhanced HO-1,NQO 1,SOD and GSH-Px,while inhabited Keap 1,MDA and LDH,which alleviated Aβ-induced oxidative stress in PC 12 cells.These provide a solid theoretical basis for the further development of ginseng polysaccharides as functional food and antioxidant drugs. 展开更多
关键词 Ginseng polysaccharide Structural characterization Intestinal microbiota FERMENTABILITY Oxidative stress
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Controllable phase-reconstruction strategy for LiFePO_(4)homogeneous regeneration:Reaction mechanism,characterization and prospect
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作者 Zihao Zeng Yi Chen +4 位作者 Chao Zhu Hai Lei Wei Sun Yue Yang Peng Ge 《Journal of Energy Chemistry》 2026年第1期553-571,I0013,共20页
The growing volume of end-of-life lithium-ion batteries(LIBs)represents both an urgent environmental challenge and a critical resource opportunity,especially for cathode materials.Among commercial cathodes,LiFePO4(LFP... The growing volume of end-of-life lithium-ion batteries(LIBs)represents both an urgent environmental challenge and a critical resource opportunity,especially for cathode materials.Among commercial cathodes,LiFePO4(LFP)dominates the market due to its favorable properties;thus,a substantial amount of LFP cathode materials is expected to retire in the near future.The conventional hydrometallurgical method suffers from high costs and serious pollution.Direct regeneration technologies,especially solid-state sintering,provide a more efficient and environmentally benign alternative by repairing cathode structures through high-temperature solid-phase reactions without extra chemical reagents.Traditional solid-state sintering faces challenges in processing spent LFP from diverse sources,struggling to achieve the homogenization of physical–chemical properties and electrochemical performance.To address the limitations above,phase homogenization with a lattice reconstruction strategy has been investigated,which can enable effective lattice reconstruction and microstructural homogenization,demonstrating robust adaptability to spent samples from variable sources.This review systematically summarizes the mechanisms,detailed steps,characterization techniques,and advances in pre-oxidation optimization(including ion-doping and coated carbon layer modification),as well as future research directions for sustainable LFP recycling.Given this,this review is expected to offer theoretical guidance for achieving homogeneous regeneration of LFP cathode. 展开更多
关键词 Spent LiFePO_(4) REGENERATION Phase-reconstruction Reaction mechanism characterIZATION
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Research on characterization methods for track irregularities
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作者 Lifeng Xin Lei Xu +3 位作者 Jiaxin Zhang Menglin Pei Jianfeng Mao Dangxiong Wang 《Railway Engineering Science》 2026年第1期25-39,共15页
The characterization of track irregularities is crucial in railway dynamics,as track irregularities are the primary source of internal excitation in railway systems.In this paper,three mathematical models are proposed... The characterization of track irregularities is crucial in railway dynamics,as track irregularities are the primary source of internal excitation in railway systems.In this paper,three mathematical models are proposed to characterize the track irregularities under different circumstances.The first model is a novel explicit track spectrum function,which performs better in reflecting the inherent periodic components of track irregularities than the existing track spectra.On this foundation,the second model,a parameterized track spectrum random model,is proposed to represent the vast measured track irregularities from the probabilistic perspective.Finally,the third model,an imprecise track spectrum interval model based on a neighborhood uniform sampling Bootstrap method,is presented to identify the confidential interval of the track spectra when the track irregularity data are limited.Three examples are illustrated to demonstrate the feasibility of the three track irregularity models in characterizing the track irregularities in different conditions.This research can help capture the railway deformation status and optimize track maintenance strategies. 展开更多
关键词 RAILWAY Track irregularity Power spectral density characterIZATION Random model Imprecise track spectrum
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A comprehensive review on oxygen vacancies modified catalysts:Synthesis,characterization,and crucial role in catalytic ozonation
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作者 Fengchen Wang Yujia Xiang +9 位作者 Yuqi Zhang Xin Zhou Jing Zhang Chuanshu He Heng Zhang Zhaokun Xiong Peng Zhou Hongyu Zhou Yang Liu Bo Lai 《Chinese Chemical Letters》 2026年第2期253-262,共10页
Among various advanced oxidation processes(AOPs),heterogeneous catalytic ozonation has garnered extensive attention in wastewater treatment owing to its broad pH range applicability and the elimination of the need for... Among various advanced oxidation processes(AOPs),heterogeneous catalytic ozonation has garnered extensive attention in wastewater treatment owing to its broad pH range applicability and the elimination of the need for additional energy input.Enhancing catalyst activity by introducing oxygen vacancies has been used extensively in heterogeneous catalytic ozonation.This paper reviews prevalent methods for the construction and characterization of oxygen vacancies.Based on a thorough examination of existing research,the role of oxygen vacancies is categorized according to their primary mechanisms of action in heterogeneous catalytic ozonation.For example,modulation of the catalyst electronic structure to enhance electron transfer;participation in the reaction as an active site to generate radicals and non-radicals;and exposure of more metal sites to enhance the reaction.Lastly,the paper delineates the limitations and future research directions concerning the role of oxygen vacancies in catalytic ozonation.This review addresses the gap in existing literature concerning the role of oxygen vacancies in catalytic ozone systems,establishes a comprehensive theoretical framework to aid in the design of efficient ozone catalysts,and delves into the functionality of oxygen vacancies in heterogeneous catalytic ozone reactions. 展开更多
关键词 Catalytic ozonation Bulk defects Surface defects Oxygen vacancies Degradation mechanism Synthesis and characterization
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High-frequency emphasized neural network reconstruction method for in situ synchrotron radiation ultrafast computed tomography characterization
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作者 Jing-Wei Li Yu Xiao +3 位作者 Yong-Cun Li Xiao-Fang Hu Guo-Hao Du Feng Xu 《Nuclear Science and Techniques》 2026年第3期5-17,共13页
There is a contradiction between the evolution rate of materials and the time resolution of SR-CT characterization in the in situ synchrotron radiation computed tomography(SR-CT)characterization of ultrafast evolution... There is a contradiction between the evolution rate of materials and the time resolution of SR-CT characterization in the in situ synchrotron radiation computed tomography(SR-CT)characterization of ultrafast evolution process.The sampling strategy of the ultra-sparse angle is an effective method for improving time resolution.Accurate reconstruction under sparse sampling conditions has always been a bottleneck problem.In recent years,convolutional neural networks have shown outstanding advantages in sparse-angle CT reconstruction given the development of deep learning.However,existing ideas did not consider the expression of high-frequency details in neural networks,limiting their application in accurate SR-CT characterization.A novel high-frequency information-constrained deep learning network(HFIC-Net)is proposed in response to this problem.Additional high-frequency information constraints are added to improve the accuracy of the reconstruction results.Further,a series of numerical reconstruction experiments are conducted to verify this new method,and the results indicate that the reconstruction results of HFIC-Net method effectively improve reconstruction quality.This new method uses only eight-angle projections to achieve the reconstruction effect of the filtered backprojection method(FBP)method in 360 projections.The results of the HFIC-Net method demonstrate clear boundaries and accurate detailed structures,correcting the misinformation caused by using other methods.For quantitative evaluation,the SSIM used to evaluate image structure similarity is increased from 0.1951,0.9212,and 0.9308 for FBP,FBP-Conv,and DDC-Net,respectively,to 0.9620 for HFIC-Net.Finally,the results of actual SR-CT experimental data indicate that the new method can suppress artifacts and achieve accurate reconstruction,and it is suitable for the in situ SR-CT accurate characterization of ultxafast evolution process. 展开更多
关键词 Accurate SR-CT characterization CT reconstruction Sparse-angle CT reconstruction problem High-frequency information constrained Deep learning
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Intelligent characterization of discontinuities and heterogeneity evaluation of potential hazard sources in high-steep rock slope by TLS-UAV technology
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作者 Changqing Liu Han Bao +5 位作者 Tianyi Wang Jingfeng Zhang Hengxing Lan Shengwen Qi Wei Yuan Shunichi Koshimura 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第1期509-527,共19页
The identification of rock mass hazard sources is fundamental for preventing rockfall and landslide disasters in mountainous regions,with rock mass structural characteristics playing a vital role in hazard assessment.... The identification of rock mass hazard sources is fundamental for preventing rockfall and landslide disasters in mountainous regions,with rock mass structural characteristics playing a vital role in hazard assessment.In this study,terrestrial laser scanning(TLS)and unmanned aerial vehicle(UAV)technologies were integrated to enhance the evaluation methodology for rock mass hazard sources,focusing on the Sichuan Yanjiang Expressway project in China.The findings demonstrate that TLS-UAV technology enhanced both spatial coverage and data density in slope modeling.Through integrated algorithmic analysis,rock discontinuities within heterogeneous datasets were systematically identified,enabling quantitative extraction and statistical analysis of key geometric parameters,including orientation,trace length,spacing,and roughness.Furthermore,quantitative models were developed for cohesion,friction angle and the morphology parameter M of in situ discontinuities,respectively,facilitating efficient mechanical parameter acquisition.A novel rock mass hazard index(RHI)was developed incorporating discontinuity geometric rating(DGR),discontinuity mechanical rating(DMR),and slope mass rating(SMR).Field validation confirmed the methodology's effectiveness in evaluating risk levels and spatial heterogeneity of rock mass hazard sources,revealing the contribution of different discontinuity sets to the rock mass hazard and identifying the primary discontinuity sets controlling instability mechanisms.This study is of great significance for evaluating discontinuity-controlled rock mass hazard sources and preventing rockfall disasters. 展开更多
关键词 High-steep slope Rock mass hazard source DISCONTINUITIES Intelligent characterization Terrestrial laser scanning(TLS) Unmanned aerial vehicle(UAV)
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明恩溥的无本译写:Chinese Characteristics的版本流变与人物特质
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作者 苏蕊 亚晓晗 《外国语文研究》 2025年第2期55-71,共17页
Chinese Characteristics作为重要的域外文献,以他者视野译写了晚清时期中国社会面貌及中国人特征。本研究以无本译写为主体理据,首先通过版本流变考察明恩溥在译写语言上的特点,由此反观其译写意图及思想来源,并深入剖析其思维认知的改... Chinese Characteristics作为重要的域外文献,以他者视野译写了晚清时期中国社会面貌及中国人特征。本研究以无本译写为主体理据,首先通过版本流变考察明恩溥在译写语言上的特点,由此反观其译写意图及思想来源,并深入剖析其思维认知的改变;进而针对1894年修订版进行碎片式底本溯源。选取文本中的典型案例,分析其译写语言内部的中国人特质,以期挖掘明恩溥译写现象背后的社会文化因素。本研究对Chinese Characteristics的考释,不仅有助于了解西方人眼中的中国国民特质,还可以此为镜,揭示明恩溥他塑中国形象中的正与偏,为今后借力使力,塑造可信、可敬、可爱的中国形象提供借鉴和参考。 展开更多
关键词 无本译写 底本溯源 版本流变 国民特质 他者视野
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Laboratory Diagnosis and Molecular Epidemiological Characterization of the First Imported Case of Lassa Fever in China 被引量:2
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作者 Yuliang Feng Wei Li +11 位作者 Mingfeng Jiang Hongrong Zhong Wei Wu Lyubo Tian Guo Chen Zhenhua Chen Can Luo Rongmei Yuan Xingyu Zhou Jiandong Li Xiaorong Yang Ming Pan 《Biomedical and Environmental Sciences》 2025年第3期279-289,共11页
Objective This study reports the first imported case of Lassa fever(LF)in China.Laboratory detection and molecular epidemiological analysis of the Lassa virus(LASV)from this case offer valuable insights for the preven... Objective This study reports the first imported case of Lassa fever(LF)in China.Laboratory detection and molecular epidemiological analysis of the Lassa virus(LASV)from this case offer valuable insights for the prevention and control of LF.Methods Samples of cerebrospinal fluid(CSF),blood,urine,saliva,and environmental materials were collected from the patient and their close contacts for LASV nucleotide detection.Whole-genome sequencing was performed on positive samples to analyze the genetic characteristics of the virus.Results LASV was detected in the patient’s CSF,blood,and urine,while all samples from close contacts and the environment tested negative.The virus belongs to the lineage IV strain and shares the highest homology with strains from Sierra Leone.The variability in the glycoprotein complex(GPC)among different strains ranged from 3.9%to 15.1%,higher than previously reported for the seven known lineages.Amino acid mutation analysis revealed multiple mutations within the GPC immunogenic epitopes,increasing strain diversity and potentially impacting immune response.Conclusion The case was confirmed through nucleotide detection,with no evidence of secondary transmission or viral spread.The LASV strain identified belongs to lineage IV,with broader GPC variability than previously reported.Mutations in the immune-related sites of GPC may affect immune responses,necessitating heightened vigilance regarding the virus. 展开更多
关键词 Lassa fever The first imported case Laboratory diagnosis Epidemiological characterization
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SiO_(2)'-CaO/(CaO+K_(2)O)(S'CK)Diagram as a Petrochemical Tool for Deciphering the Tectono-Magmatic Characterization of Granitoid Suites 被引量:1
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作者 SUN Mingming WANG Yang 《Acta Geologica Sinica(English Edition)》 2025年第2期598-610,共13页
The SiO_(2)'-CaO/(CaO+K_(2)O)(S'CK)diagram is an empirically derived major element-based equivalent to the modal IUGS alkali feldspar-quartz-plagioclase classification scheme for granitoids.It employs the cont... The SiO_(2)'-CaO/(CaO+K_(2)O)(S'CK)diagram is an empirically derived major element-based equivalent to the modal IUGS alkali feldspar-quartz-plagioclase classification scheme for granitoids.It employs the content of SiO_(2)and CaO/(CaO+K_(2)O)ratio to approximate the IUGS classification diagram and a normative-based Q'-ANOR plot.Four trends have been superimposed onto the SiO_(2)'-CaO/(CaO+K_(2)O)diagram based on published datasets from the Peninsular Ranges(calcic:C),Tuolumne(calc-alkalic:CA),Sherman(alkali-calcic:AC),and Bjerkreim-Sokndal(alkalic:A)batholiths,which were employed to constrain the positions of the C-CA,CA-AC and AC-A suite boundaries on the SiO_(2)versus(Na_(2)O+K_(2)O-CaO)(or modified alkali-lime index,MALI)granitic classification diagram.A merit of the SiO_(2)'-CaO/(CaO+K_(2)O)plot is identifying rock types comprising a suite and their relative abundances.The distinguished projections of five typical granitoid assemblages,which are summarized by Bonin et al.(2020),demonstrate the ability of SiO_(2)'-CaO/(CaO+K_(2)O)diagram to decipher their petrogenesis.The SiO_(2)'-CaO/(CaO+K_(2)O)plots for the plutonic suites of'known'tectonic settings can reveal their evolution paths and the lithological statistics.Accordingly,it is suggested that the SiO_(2)'-CaO/(CaO+K_(2)O)plot can distinguish the tectonic environments of plutonic suits by comparing the plutonic suites or batholiths of'unknown'tectonic context to the published datasets from granitoid suites formed within'known'tectonic settings.The modified SiO_(2)'-CaO/(CaO+K_(2)O)diagram links the bulk chemical composition of granitoid suites to the likely source,magmatic evolution,and tectonic setting;thus,it may be a useful tectono-magmatic classification scheme for granitoid suites. 展开更多
关键词 classification of granitoid major-element chemistry SiO_(2)'–CaO/(CaO+K_(2)O)diagram tectono-magmatic character
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Recent advances of metal vacancies in energy and environmental catalysis:Synthesis,characterization,and roles
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作者 Long Sun Shunzheng Zhao +4 位作者 Sirui Gao Ronghui Zhu Yiran Tan Xiaolong Tang Honghong Yi 《Green Energy & Environment》 SCIE EI CAS 2025年第1期84-108,共25页
With the ongoing depletion of fossil fuels,energy and environmental issues have become increasingly critical,necessitating the search for effective solutions.Catalysis,being one of the hallmarks of modern industry,off... With the ongoing depletion of fossil fuels,energy and environmental issues have become increasingly critical,necessitating the search for effective solutions.Catalysis,being one of the hallmarks of modern industry,offers a promising avenue for researchers.However,the question of how to significantly enhance the performance of catalysts has gradually drawn the attention of scholars.Defect engineering,a commonly employed and effective approach to improve catalyst activity,has become a significant research focus in the catalysis field in recent years.Nonmetal vacancies have received extensive attention due to their simple form.Consequently,exploration of metal vacancies has remained stagnant for a considerable period,resulting in a scarcity of comprehensive reviews on this topic.Therefore,based on the latest research findings,this paper summarizes and consolidates the construction strategies for metal vacancies,characterization techniques,and their roles in typical energy and environmental catalytic reactions.Additionally,it outlines potential challenges in the future,aiming to provide valuable references for researchers interested in investigating metal vacancies. 展开更多
关键词 Metal vacancies CATALYSIS Construction strategies characterization techniques ROLES
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Synthesis and crystal structure characterization of yttrium imido complex:The reactivity of 2-substituted-1-amino-o-carborane with yttrium dialkyl complex
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作者 GUO Liping 《无机化学学报》 北大核心 2025年第7期1409-1415,共7页
2-substituted-1-amino-o-carboranes 2-R-1-NH_(2)-o-C_(2)B_(10)H_(10)(R=CH_(3),1a;R=Ph,1b)were synthesized and the reactions of these compounds with the yttrium dialkyl complex[Y(L)(CH_(2)SiMe3)_(2)](L=[2-(2,5-Me_(2)C_(... 2-substituted-1-amino-o-carboranes 2-R-1-NH_(2)-o-C_(2)B_(10)H_(10)(R=CH_(3),1a;R=Ph,1b)were synthesized and the reactions of these compounds with the yttrium dialkyl complex[Y(L)(CH_(2)SiMe3)_(2)](L=[2-(2,5-Me_(2)C_(4)H_(2)N)C_(6)H4NC(Ph)=NDipp]-,Dipp=2,6-iPr_(2)C_(6)H_(3))were investigated.The 1H NMR spectroscopy indicate that the reaction of ytrrium dialkyl complex with one equivalent of 2-R-1-NH_(2)-o-C_(2)B_(10)H_(10) produce the mixture of ytrrium alkyl-amido complex[Y(L)(2-R-1-NH-o-C_(2)B_(10)H_(10))(CH_(2)SiMe3)](R=CH_(3),2a;R=Ph,2b)and bis(amido)complex[Y(L)(2-R-1-NH-o-C_(2)B_(10)H_(10))_(2)](R=CH_(3),3a;R=Ph,3b).The yttrium bridging imido complex[Y(L)(2-CH_(3)-1-N-o-C_(2)B_(10)H_(10))]_(2)(4a)was obtained by heating the mixture at 55℃for 12 h.Complex 3a was isolated and characterized by treating the yttrium dialkyl complex with two equivalents of 1a.The structures of complexes 3a and 4a were verified by single-crystal Xray diffraction.CCDC:2424136,3a;2424137,4a. 展开更多
关键词 yttrium imide O-CARBORANE synthesis structure characterization
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Mechanistic Insights into Electrocatalytic Urea Oxidation Reaction Through in situ Characterizations
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作者 Suzhen Bai Yi Zeng +3 位作者 Zhengshan Tian Kesheng Cao Xingwu Li Haoqi Wang 《化学进展》 北大核心 2025年第12期1769-1791,共23页
The electrocatalytic urea oxidation reaction(UOR)has emerged as an energy-efficient alternative to the traditional oxygen evolution reaction for hydrogen production,with mechanistic understanding being critical for th... The electrocatalytic urea oxidation reaction(UOR)has emerged as an energy-efficient alternative to the traditional oxygen evolution reaction for hydrogen production,with mechanistic understanding being critical for the rational design of catalysts.This review systematically summarizes recent advances in in situ characterization techniques for elucidating the dynamic reaction mechanisms of UOR.Studies reveal that phase transitions,valence state migration,and electronic structure evolution of catalysts under operational conditions are key factors governing activity and stability.Techniques such as in situ X-ray diffraction,X-ray absorption spectroscopy,Raman spectroscopy,and Fourier-transform infrared spectroscopy enable real-time monitoring of catalyst reconstruction,intermediate evolution,and interfacial adsorption behavior,overcoming the environmental deviations inherent in conventional ex situ characterization.When combined with theoretical calculations,these methods provide direct evidence for identifying active-site configurations,reaction pathways,and rate-determining steps.In addition,special emphasis is placed on multimodal in situ strategies for deciphering synergistic effects in nickel-based catalysts,while current challenges,including non-alkaline systems,real wastewater environments,and multi-metal cooperation mechanisms,are critically discussed.Future research should focus on developing novel in situ approaches for complex systems and establishing a mutually reinforcing framework integrating theoretical prediction and experimental validation,thereby advancing UOR catalyst design from empirical exploration to mechanism-guided optimization. 展开更多
关键词 urea oxidation reaction mechanistic insight in-situ characterizations active sites dynamic evolution
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In situ synthesis,crystal structure,and magnetic characterization of a trinuclear copper complex based on a multi-substituted imidazo[1,5-a]pyrazine scaffold
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作者 WANG Zhaodong 《无机化学学报》 北大核心 2025年第3期597-604,共8页
A trinuclear copper complex [Cu_(3)(L2)_(2)(SO_(4))_(2)(H_(2)O)_(7)]·8H_(2)O(1)(HL2=1-hydroxy-3-(pyrazin-2-yl)-N-(pyrazin-2-ylmethyl)imidazo[1,5-a]pyrazine-8-carboxamide) with a multi-substituted imidazo[1,5-a]py... A trinuclear copper complex [Cu_(3)(L2)_(2)(SO_(4))_(2)(H_(2)O)_(7)]·8H_(2)O(1)(HL2=1-hydroxy-3-(pyrazin-2-yl)-N-(pyrazin-2-ylmethyl)imidazo[1,5-a]pyrazine-8-carboxamide) with a multi-substituted imidazo[1,5-a]pyrazine scaffold was serendipitously prepared from the reaction of the pro-ligand of H_(2)L1(N,N'-bis(pyrazin-2-ylmethyl)pyrazine-2,3-dicarboxamide) with CuSO_(4)·5H_(2O) in aqueous solution at room temperature.Complex 1 was characterized by IR,single-crystal X-ray analysis,and magnetic susceptibility measurements.Single-crystal X-ray analysis reveals that the complex consists of three Cu(Ⅱ) ions,two in situ transformed L2~-ligands,two coordinated sulfates,seven coordinated water molecules,and eight uncoordinated water molecules.Magnetic susceptibility measurement indicates that there are obvious ferromagnetic coupling interactions between the adjacent Cu(Ⅱ) ions in 1.CCDC:1852713. 展开更多
关键词 amide ligand copper complex single crystal structure C-N coupling magnetic characterization
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Heterologous Expression,Purification and Enzymatic Characterization of Xylitol Dehydrogenase from the Thermophilic Fungus Talaromyces emersonii
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作者 MENG Er QU Cong +8 位作者 YI Ke LI Hui-Min DUAN Xin-Yi ZHANG Zhe-Yuan HE Shao-Long LUO Yu-Tao WU Lei ZHANG Dong-Yi LIU Chang-Jun 《中国生物化学与分子生物学报》 北大核心 2025年第7期1007-1018,共12页
The xylitol dehydrogenase(XDH)is a crucial enzyme involved in the xylose utilization in pentose⁃catabolizing yeasts and fungi.In addition to producing xylulose,XDH can also be employed to develop a biosensor for monit... The xylitol dehydrogenase(XDH)is a crucial enzyme involved in the xylose utilization in pentose⁃catabolizing yeasts and fungi.In addition to producing xylulose,XDH can also be employed to develop a biosensor for monitoring xylitol concentration.In this study,the gene encoding the thermophilic fungus Talaromyces emersonii XDH(TeXDH)was heterologously expressed in Escherichia coli BL21(DE3)at 16℃in the soluble form.Recombinant TeXDH with high purity was purified by using a Ni⁃NTA affinity column.Size⁃exclusion chromatography and SDS⁃PAGE analysis demonstrated that the puri⁃fied recombinant TeXDH exists as a native trimer with a molecular mass of approximately 116 kD,and is composed of three identical subunits,each with a molecular weight of around 39 kD.The TeXDH strictly preferred NAD^(+)as a coenzyme to NADP^(+).The optimal temperature and pH of the TeXDH were 40℃and 10.0,respectively.After EDTA treatment,the enzyme activity of TeXDH decreased to 43.26%of the initial enzyme activity,while the divalent metal ions Mg^(2+)or Ca^(2+)could recover the enzyme activity of TeXDH,reaching 103.32%and 110.69%of the initial enzyme activity,respectively,making them the optimal divalent metal ion cofactors for TeXDH enzyme.However,the divalent metal ions of Mn^(2+),Ni^(2+),Cu^(2+),Zn^(2+),Co^(2+),and Cd^(2+)significantly inhibited the activity of TeXDH.ICP⁃MS and molecular doc⁃king studies revealed that 1 mol/L of TeXDH bound 2 mol/L Zn^(2+)ions and 1 mol/L Mg^(2+)ion.Further⁃more,TeXDH exhibited a high specificity for xylitol,laying the foundation for the development of future xylitol biosensors. 展开更多
关键词 xylitol dehydrogenase(XDH) Talaromyces emersonii heterologous expression enzymatic characterization
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A Convolutional Neural Network Based Optical Character Recognition for Purely Handwritten Characters and Digits
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作者 Syed Atir Raza Muhammad Shoaib Farooq +3 位作者 Uzma Farooq Hanen Karamti Tahir Khurshaid Imran Ashraf 《Computers, Materials & Continua》 2025年第8期3149-3173,共25页
Urdu,a prominent subcontinental language,serves as a versatile means of communication.However,its handwritten expressions present challenges for optical character recognition(OCR).While various OCR techniques have bee... Urdu,a prominent subcontinental language,serves as a versatile means of communication.However,its handwritten expressions present challenges for optical character recognition(OCR).While various OCR techniques have been proposed,most of them focus on recognizing printed Urdu characters and digits.To the best of our knowledge,very little research has focused solely on Urdu pure handwriting recognition,and the results of such proposed methods are often inadequate.In this study,we introduce a novel approach to recognizing Urdu pure handwritten digits and characters using Convolutional Neural Networks(CNN).Our proposed method utilizes convolutional layers to extract important features from input images and classifies them using fully connected layers,enabling efficient and accurate detection of Urdu handwritten digits and characters.We implemented the proposed technique on a large publicly available dataset of Urdu handwritten digits and characters.The findings demonstrate that the CNN model achieves an accuracy of 98.30%and an F1 score of 88.6%,indicating its effectiveness in detecting and classifyingUrdu handwritten digits and characters.These results have far-reaching implications for various applications,including document analysis,text recognition,and language understanding,which have previously been unexplored in the context of Urdu handwriting data.This work lays a solid foundation for future research and development in Urdu language detection and processing,opening up new opportunities for advancement in this field. 展开更多
关键词 Image processing natural language processing handwritten Urdu characters optical character recognition deep learning feature extraction CLASSIFICATION
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Nonreferential Uses of “I” and Its Perspectival Character
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作者 Minyao Huang 《逻辑学研究》 2025年第3期115-127,共13页
The English“T” is widely held as a well-behaved Kaplanian indexical that has a directly-referential content and a character which imples immunity to self misidentification.In this paper I present uses of“T”outside... The English“T” is widely held as a well-behaved Kaplanian indexical that has a directly-referential content and a character which imples immunity to self misidentification.In this paper I present uses of“T”outside attitudal contexts that are not directly referential yet exhibit immunity to self misidentification.They include uses of“I”for simulation and for counterfactual self portrait.I argue that they(i)challenge the non-shiftability and the rigidity arguments for the direct reference view,and(1)require a revision of the character of“T”to reflect the sensitivity of its content to the perspective from which the speaker identifies herself. 展开更多
关键词 Kaplanian indexical simulation counterfactual self portraiti perspectival character self misidentification counterfactual self portrait nonreferential uses
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Deep Learning-Based Natural Language Processing Model and Optical Character Recognition for Detection of Online Grooming on Social Networking Services
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作者 Sangmin Kim Byeongcheon Lee +2 位作者 Muazzam Maqsood Jihoon Moon Seungmin Rho 《Computer Modeling in Engineering & Sciences》 2025年第5期2079-2108,共30页
The increased accessibility of social networking services(SNSs)has facilitated communication and information sharing among users.However,it has also heightened concerns about digital safety,particularly for children a... The increased accessibility of social networking services(SNSs)has facilitated communication and information sharing among users.However,it has also heightened concerns about digital safety,particularly for children and adolescents who are increasingly exposed to online grooming crimes.Early and accurate identification of grooming conversations is crucial in preventing long-term harm to victims.However,research on grooming detection in South Korea remains limited,as existing models trained primarily on English text and fail to reflect the unique linguistic features of SNS conversations,leading to inaccurate classifications.To address these issues,this study proposes a novel framework that integrates optical character recognition(OCR)technology with KcELECTRA,a deep learning-based natural language processing(NLP)model that shows excellent performance in processing the colloquial Korean language.In the proposed framework,the KcELECTRA model is fine-tuned by an extensive dataset,including Korean social media conversations,Korean ethical verification data from AI-Hub,and Korean hate speech data from Hug-gingFace,to enable more accurate classification of text extracted from social media conversation images.Experimental results show that the proposed framework achieves an accuracy of 0.953,outperforming existing transformer-based models.Furthermore,OCR technology shows high accuracy in extracting text from images,demonstrating that the proposed framework is effective for online grooming detection.The proposed framework is expected to contribute to the more accurate detection of grooming text and the prevention of grooming-related crimes. 展开更多
关键词 Online grooming KcELECTRA natural language processing optical character recognition social networking service text classification
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Analysis of the Complexity and Symbolic Significance of Lensky’s Character in Eugene Onegin
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作者 Shiwei Liang 《Journal of Contemporary Educational Research》 2025年第3期67-72,共6页
The character of Lensky in Eugene Onegin is one of the most discussed figures in the novel.He is the friend of Eugene Onegin and represents a contradictory personality.In the novel,Lensky displays a complex set of cha... The character of Lensky in Eugene Onegin is one of the most discussed figures in the novel.He is the friend of Eugene Onegin and represents a contradictory personality.In the novel,Lensky displays a complex set of characteristics,appearing both elegant and noble on the outside,while concealing a deep inner loneliness and conflict.His attitude toward love and his dissatisfaction with society make him a dramatic and profound character in the story.By analyzing the character of Lensky,we can explore his role in the novel and his relationships with other characters.Lensky’s presence not only enriches the plot but also presents a figure filled with inner contradictions and emotional struggles.His friendship and rivalry with Eugene Onegin,as well as his admiration and helplessness in regard to Olga,showcase his complex inner world and reflections on life.Furthermore,the character of Lensky carries a certain symbolic significance.He can be seen as a metaphor for Russian society and culture at the time.His loneliness and inner conflict symbolize the limitations of Russian society and culture,while also reflecting Pushkin’s idealized pursuit of love and friendship,as well as his critical view of reality.In conclusion,through a deep analysis of Lensky’s character,we can better understand the portrayal of characters and the development of the plot in Eugene Onegin.It also provides readers with a perspective on Pushkin’s thoughts and observations on human nature,society,and culture. 展开更多
关键词 character ANALYSIS PERSONALITY Symbolic significance
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Research on the Reform of Approaches to Early Childhood Character Education
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作者 Li Longqing Liu Jialing 《Contemporary Social Sciences》 2025年第6期102-115,共14页
Early childhood character education is a critical element in shaping an individual’s moral foundation and fostering a sense of social responsibility.It plays a fundamental role in overall personal development.Althoug... Early childhood character education is a critical element in shaping an individual’s moral foundation and fostering a sense of social responsibility.It plays a fundamental role in overall personal development.Although China’s early childhood character education has made progress with the support of policies and practical exploration,it still faces challenges such as the homogenization of educational models,a formalization of home-kindergarten cooperation,a single-dimensional evaluation system,and a need for further improvement in teachers’professional competence in character education.This paper draws on core theories of character education(e.g.,social learning theory and cognitive moral development theory)and incorporates representative case studies to conduct an in-depth analysis of the current landscape and associated challenges.It proposes innovative approaches,which include establishing a“threefold”system of implementation,enhancing the mechanisms for home-kindergarten co-education,optimizing and ensuring a multidimensional and dynamic evaluation system,equitably allocating teaching resources,and expanding the social support networks.The aim is to offer theoretical reference and practical solutions to promote the scientific and systematic development of early childhood character education. 展开更多
关键词 character education early childhood development home-kindergarten co-education evaluation mechanism implementation pathway
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