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Effects of carbon content on the microstructure and tensile properties of a low-density steel

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 391-401页

作者： Yongxuan Shang Mingyu Fan Shuyong Jiang Zhongwu zhang Key Laboratory of Superlight Materials and Surface Technology Ministry of EducationCollege of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001China State Key Laboratory of Metal Material for Marine Equipment and Application Iron&Steel Research Institute of Ansteel Group CorporationAnshan 114009China

Carbon can change the phase components of low-density steels and influence the mechanical *** this study,a new method to control the carbon content and avoid the formation ofδ-ferrite by decarburization treatment was *** microstructural changes and mechanical characteristics with carbon content induced by decarburization were systematically ***-Jaoul(C-J)analysis was employed to examine the work hardening characteristics during the tensile *** decarburization by heat treatments,the carbon content within the austenite phase decreased,while Mn and Al were almost unchanged;this made the steel with full austenite transform into the austenite and ferrite dual ***,(Ti,V)C carbides existed in both matrix phase and the mole fraction almost the *** addition,the formation of other carbides *** loss induced a decrease in strength due to the weakening of the carbon solid *** the steel with the single austinite,the deformation mode of austenite was the dislocation planar glide,resulting in the formation of *** the dual-phase steel,the deformation occurred by the dislocation planar glide of austenite first,with the increase in strain,the cross slip of ferrite took place,forming dislocation cells in *** the late stage of deformation,the work hardening of austinite increased rapidly,while that of ferrite increased slightly.

关键词： low-density steels carbon content decarburization strengthening mechanisms work hardening behavior

Yizhijiannao Granule and a combination of its effective monomers,icariin and Panax notoginseng saponins,inhibit early PC12 cell apoptosis induced by beta-amyloid(25-35)

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Neural Regeneration Research 2012年第24期7卷 1845-1850页

作者： ting zhang Zhanwei zhang Keli dong Guangcheng Li Hong Zhu Department of Traditional Chinese Medicine Xiangya Third HospitalCentral South UniversityChangsha 410013Hunan ProvinceChina Department of Neurosurgery First Affiliated Hospital of Hunan University of Chinese MedicineChangsha 410007Hunan ProvinceChina

One of our previous studies showed that Yizhijiannao Granule,a compound Chinese medicine, effectively improved the clinical symptoms of Alzheimer’s *** the present study,we established a model of Alzheimer’s disease using beta-amyloid（25-35）in PC12 cells,and treated the cells with Yizhijiannao Granule and its four monomers,i.e.,icariin,catechin,Panax notoginseng saponins,and eleutheroside *** cytometry showed that Yizhijiannao Granule-containing serum, icariin,Panax notoginseng saponins,and icariin＋Panax notoginseng saponins were protective against beta-amyloid（25-35）-induced injury in PC12 *** in combination with Panax notoginseng saponins significantly inhibited early apoptosis of PC12 cells with beta-amyloid （25-35）-induced injury compared to icariin or Panax notoginseng saponins *** effects of icariin＋Panax notoginseng saponins were similar to the effects of Yizhijiannao *** findings indicate that two of the effective monomers of Yizhijiannao Granule,icariin and Panax notoginseng saponins,can synergistically inhibit early apoptosis of PC12 cells induced by beta-amyloid（25-35）.

关键词： Alzheimer’s disease icariin Panax notoginseng Saponins Yizhijiannao Granule Chinese medicine monomer beta-amyloid protein PC12 cell Chinese medicine neural regeneration

Preparation of High-performance Polyimide Fibers with Wholly Rigid Structures Containing Benzobisoxazole Moieties

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Chinese Journal of Polymer Science 2022年第3期40卷 280-289,I0007页

作者： Yu-ting Fang Feng Gan Jie dong Xin Zhao Xiu-ting Li Qing-Hua zhang State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai 201620China School of Textile Materials and Engineering Wuyi UniversityJiangmen 529020China

In this work, a fully rigid coplanar symmetric heterocyclic unit was introduced into the rigid polyimide macromolecular backbone structure to prepare high-performance polyimide fibers. The novel co-polyimide(co-PI) fibers based on 3,3',4,4'-biphenyltetracarboxylic anhydride(BPDA), p-phenylenediamine(PDA) and 2,6-(4,4'-diaminodiphenyl) benzo[1,2-d:5,4-d'] bisoxazole(PBOA) were fabricated via a twostep wet-spinning method. The effects of benzobisoxazole moiety on spinnability, aggregation structure, and mechanical properties of fibers were systematically discussed. The detailed structural analysis revealed that the well-defined aggregation structures of co-PI fibers were obtained from initial amorphous structure when post hot-drawing temperature was higher than 460 ℃ under proper drawing ratio, and the incorporation PBOA into BPDA-PDA structures produced more compact structural co-PI fiber than homo BPDA-PDA fiber. The BPDA-PDA/PBOA co-PI fibers exhibited optimum tensile strength and modulus of 2.65 and 103 GPa, which increased by 182% and 84% compared to the homo BPDA-PDA fiber, respectively.

关键词： Polyimide fiber Benzobisoxazole Co-polymerization Microstructure Mechanical properties

Dry-spun Polyimide Fibers with Excellent Thermal Stability,Intrinsic Flame Retardancy and Ultralow Smoke Release

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Chinese Journal of Polymer Science 2022年第11期40卷 1422-1431页

作者： Han dong Yu-Ping Wang Xiu-ting Li Xin Zhao Jie dong Qing-Hua zhang State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai201620China Jiangsu New Vision Advanced Functional Fiber Innovation Center Co. Ltd.Suzhou215000China

Polymer fiber with an ultrahigh thermal stability,superior flame retardancy and low smoke release during combustion is urgently needed and a crucial challenge for developing advanced fireproof *** this study,a series of high-performance polyimide fibers are synthesized by copolymerizing 4,4'-diaminodiphenylmethane(MDA)into the pyromellitic dianhydride-p-phenylenediamine(PMDA-PDA)backbone for synergistically solving the technical challenge of poor fiber processing ability of these polyimides with a high inherent molecular *** glass transition temperature(Tg)of resultant fibers with the PDA molar ratio over 50 mol%reaches above 420℃ and their 10 wt%weight loss temperature(T10%)is within 543-633℃.For the typical fiber containing 80 mol%of PDA,the limiting oxygen index(LOI)reaches 39%and exhibits a rapid self-extinguishing performance after deviating from the ***,this fiber exhibits the minimum heat release rate of 14.1 kW/m^(2) in a long ignition time of 813 s during combustion,revealing its better flame retardancy than the well-known Nomex fiber with a heat release rate of 140.6 kW/m^(2) during the 120 s ***,the total smoke production of this polyimide fiber is only 1/9 of the Nomex ***,the excellent flame retardancy of polyimide fibers indicating them more attractive as the fireproof materials in the field of emergency protection.

关键词： Polyimide fiber Copolymerization Thermal stability Flame retardancy Smoke release

Icariin and differential protein expression in the entorhinal area of senescence-accelerated mouse prone 8 mice

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Neural Regeneration Research 2011年第18期6卷 1370-1374页

作者： ting zhang Zhanwei zhang Keli dong Guangcheng Li Hong Zhu Department of Chinese Medicine Third Xiangya Hospital of Central South University Changsha 410013 Hunan Province China Department of Neurosurgery First Hospital of Hunan University of Chinese Medicine Changsha 410007 Hunan Province China

The present study sought to explore the mechanism of action by which icariin, an active component of Epimedii Herba, treats Alzheimer＇s disease at the proteomics level. Two-dimensional gel electrophoresis was used to isolate total protein from the entorhinal cortex of senescence-accelerated mouse prone 8 （SAMP8） mice, and differential protein spots were obtained. Corresponding peptide mass fingerprinting was conducted through mass spectrography to identify differential protein spots. Twenty-six differential protein spots were found in the entorhinal area of SAMP8 mice at 8 weeks following intragastdc perfusion with icariin and double distilled water. Fourteen spots were identified, which were involved in mitochondrial energy metabolism, oxidative stress, and neuronal function. The results revealed that icafiin can regulate the expression of various proteins in the entorhinal cortex of SAMP8 mice, and treat Alzheimer＇s disease by improving mitochondfial function, suppressing oxidative stress, inhibiting neural cell apoptosis, and protecting neurons.

关键词： icariin Alzheimer's disease entorhinal cortex proteomics traditional Chinese medicine neural regeneration

Synergistically enhanced ORR and HER performance on Co-N-C coupled in-situ generated PtCo intermetallic

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Journal of Energy Chemistry 2025年第1期100卷 721-729页

作者： Guanyu Luo Min Song Lulu An Xiao Huang Qian zhang Chenhao zhang Tao Shen Shuang Wang Deli Wang Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology) Ministry of Education School of Chemistry and Chemical Engineering Huazhong University of Science and Technology

Integrating multi-scale sites in a composite catalyst is vital to realize efficient ***,a synergistic composite catalyst consisting of Co atomic sites and in-situ generated PtCo intermetallic compounds （IMCs）(o-PtCo@CoNC) is proposed through Co pre-anchoring and subsequent impregnation-reduction *** loading of Co atoms provides a chance for in-situ generating PtCo ordered intermetallic *** remaining Co single atoms and PtCo IMCs construct synergistic electrocatalytic *** from the ordered structure,synergistic effect of Pt Co IMCs and Co single atoms,o-PtCo@CoNC exhibits excellent electrocatalytic performance for oxygen reduction reaction （ORR） and hydrogen evolution reaction （HER） with mass activity of 1.21 A mgPt-1（at 0.9 V） and5.70 A mgPt-1（at an overpotential of 100 mV）,***,o-PtCo@CoNC delivers negligible loss of half-wave potential and overpotential during long-term stability test in acid solutions,with 13 mV decay after 50,000 potential cycles for ORR and a 2.7 mV decay after 20,000 potential cycles for *** integration strategy of single-atomic sites coupled IMCs paves the way for enhancing the activity and durability of Pt-based electrocatalysts.

关键词： Electrolytic reduction

Satellite remote sensing reveals overwhelming recovery of forest from disturbances in Asia

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Atmospheric and Oceanic Science Letters 2025年第1期18卷 46-51页

作者： Yiying Zhu Hesong Wang Anzhi zhang School of Ecology and Nature Conservation Beijing Forestry UniversityBeijingChina Key Laboratory of Regional Climate and Environment for Temperate East Asia Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina College of Forestry and Landscape Architecture Xinjiang Agricultural UniversityUrumqiChina

Forest ecosystems play key roles in mitigating human-induced climate change through enhanced carbon uptake;however,frequently occurring climate extremes and human activities have considerably threatened the stability of *** the same time,detailed accounts of disturbances and forest responses are not yet well quantified in *** study employed the Breaks For Additive Seasonal and Trend method-an abrupt-change detection method-to analyze the Enhanced Vegetation Index time series in East Asia,South Asia,and Southeast *** approach allowed us to detect forest disturbance and quantify the resilience after *** showed that 20%of forests experienced disturbance with an increasing trend from 2000 to 2022,and Southeast Asian countries were more severely affected by ***,95%of forests had robust resilience and could recover from disturbance within a few *** resilience of forests suffering from greater magnitude of disturbance tended to be stronger than forests with lower disturbance *** summary,this study investigated the resilience of forests across the low and middle latitudes of Asia over the past two *** authors found that most forests exhibited good resilience after disturbance and about two-thirds had recovered to a better state in *** findings of this study underscore the complex relationship between disturbance and resilience,contributing to comprehension of forest resilience through satellite remote sensing.

关键词： Forest ecosystem Enhanced vegetation index Breaks for additive seasonal and trend method Disturbance Resilience

Concentration and source identification of polycyclic aromatic hydrocarbons and phthalic acid esters in the surface water of the Yangtze River Delta,China

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Journal of Environmental Sciences 2012年第2期24卷 335-342页

作者： Lifei zhang Liang dong Lijun Ren Shuangxin Shi Li Zhou ting zhang Yeru Huang State Environmental Protection Key Laboratory of Dioxin Pollution Control National Research Center for Environmental Analysis and Measurement Beijing 100029 China

The pollution from polycyclic aromatic hydrocarbons（PAHs） and phthalic acid esters（PAEs） in the surface water of the rapidly urbanized Yangtze River Delta region was *** surface water samples were collected in June *** samples were liquid-liquid extracted using methylene chloride and analyzed by gas chromatography-mass *** of PAHs and PAEs ranged 12.9-638.1 ng/L and 61-28550 ng/L,***,naphthalene,pyrene,phenanthrene,di-2ethylhexyl phthalate,and di-n-butyl phthalate were the most abundant compounds in the *** water samples were moderately polluted with benzo[a]pyrene according to China＇s environmental quality standard for surface *** two highest concentrations of PAHs and PAEs occurred in samples from Taihu Lake,Wuxi City and the western section of Yangchenghu *** sources of pollution at S7 were petroleum combustion and the plastics industry,and at Yangchenghu Lake were petroleum combustion and domestic *** in samples from the Beijing-Hangzhou Grand Canal originated from diesel *** were no obvious sources of pollution for the other water *** results can be used as reference levels for future monitoring programs of pollution from PAHs and PAEs.

关键词： polycyclic aromatic hydrocarbons phthalic acid esters Yangtze River Delta surface water

Nonlocal effect on resonant radiation force exerted on semiconductor coupled quantum well nanostructures

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Chinese Physics B 2019年第6期28卷 349-356页

作者： Jin-Ke zhang ting-ting zhang Yu-Liang zhang Guang-Hui Wang dong-Mei Deng Guangzhou Key Laboratory for Special Fiber Photonic Devices South China Normal UniversityGuangzhou 510006China Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices South China Normal UniversityGuangzhou 510006China

Based on the microscopic nonlocal optical response theory, the resonant radiation force exerted on a semiconductorcoupled quantum well nanostructure(CQWN), induced by the nonlocal interaction between lasers and electrons in conduction bands, is investigated for two different polarized states. The numerical results show that the spatial nonlocality of optical response can cause a radiation shift(blue-shift) for the spectrum of the resonant radiation force, which is dependent on the CQWN width ratio, the barrier height, and polarized states sensitively. It is also confirmed that the resonant radiation force is steerable by the incident and polarized directions of incident light. This work may provide an advantageous method for detecting internal quantum properties of nanostructures, and open novel and raising possibilities for optical manipulation of nano-objects using laser-induced radiation force.

关键词： nonlocal effect resonant radiation force coupled quantum well