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Influence of Thermal Temperature on the Structure and Sealed Micropores of Stabilized Polyacrylonitrile Fibers

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che.ical Research in Chinese Universities 2017年第2期33卷 312-317页

作者： Zhao, Ruixue Zhao, Xudong Gao, Zhongmin Liu, Xiaoyang che. xiaolei State Key Laboratory of Inorganic Synthesis and Preparative che.istry College of Chemistry Jilin University Changchun P. R. China College of Physics Jilin University Changchun P. R. China

Thermal stabilization is an important process in carbon fibers＇ production, during which the polyacryloni-trile fibers are heated from 180℃ to 280 ℃ in air. In this study, the samples were characterized by X-ray diffraction,Fourier infrared spectroscopy, differential scanning calorimetry, small angle X-ray Scattering（SAXS） and mechanicaltensile tests. A new rule was suggested by the results of structural characterization for the cyclization, dehydrogena-tion and oxidation reactions that were observed to be drastic from 200 ℃ to 220 ℃, from 220 ℃ to 250 ℃, and inthe later period of the thermal stabilization reactions, respectively. The sizes, shapes and distributions of the sealedmicropores were obtained from the SAXS data. The breaking elongation was significantly affected by the drasticcyclization and dehydrogenation reactions. The breaking force was affected considerably by the bigger micropores,especially from 220 ℃ to 250 ℃, owing to the drastic dehydrogenation reactions.

关键词： Polyacrylonitrile fiber Thermal stabilization Micropore

Multi-mode Multi-frequency GNSS-IR Combination System for Sea Level Retrieval

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Journal of Geodesy and Geoinformation Science 2023年第2期6卷 32-39页

作者： Wenyue che.xiaolei WANG Xiufeng HE Jin LIU School of Earth Sciences and Engineering Hohai UniversityNanjing 211100China

With the development of Global Navigation Satellite Systems(GNSS),geodetic GNSS receivers have been utilized to monitor sea levels using GNSS-Interferometry Reflectometry(GNSS-IR)*** multi-mode,multi-frequency signals of GPS,GLONASS,Galileo,and Beidou can be used for GNSS-IR sea level retrieval,but combining these retrievals remains *** address this issue,a GNSS-IR sea level retrieval combination system has been developed,which begins by analyzing error sources in GNSS-IR sea level retrieval and establishing and solving the GNSS-IR retrieval *** paper focuses on two key points:time window selection and equation *** stability of the retrieval combination equations is determined by the condition number of the coefficient matrix within the time *** impact of ill-conditioned coefficient matrices on the retrieval results is demonstrated using an extreme case of SNR data with only ascending or descending *** determining the time window and removing ill-conditioned equations,the multi-mode,multi-frequency GNSS-IR retrieval is *** from three International GNSS Service(IGS)stations show that the combination method produces high-precision,high-resolution,and high-reliability sea level retrieval combination sequences.

关键词： GNSS-IR sea level retrieval multi-mode multi-frequency combination equation stability

Investigation of Voids in Polyacrylonitrile Fibers by USAXS and SAXS

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che.ical Research in Chinese Universities 2019年第6期35卷 1070-1075页

作者： TANG Haitong MENG Fanling LIU Yan JIN Shi WANG Xiaodong GAO Zhongmin che.xiaolei Key Laboratory of Automobile Materials Ministry of EducationCollege of Materials Science and EngineeringJilin UniversityChangchun 130012P.R.China School of Material Science and Engineering Jilin Jianzhu UniversityChangchun 130018P.R.China First Hospital of Jilin University Changchun 130021P.R.China State Key Laboratory of Inorganic Synthesis&Preparative che.istry College of ChemistryJilin UniversityChangchun 130012P.R.China College of Physics Jilin UniversityChangchun 130012P.R.China

The void structure of polyacrylonitrile(PAN)fibers was investigated using ultra-small angle X-ray scat-tering(USAXS)and small angle X-ray scattering(SAXS).A quantitative method was developed to analyze connected USAXS/SAXS data and thus determine the void parameters of PAN *** results showed that voids affected the mechanical performance of PAN fibers and were present throughout the entire wet-spinning *** the abso-lute quantity and size of voids decreased,the tensile strength and modulus of PAN fibers *** void para-meters were optimized by controlling the production process,and thus the tensile strength and modulus of PAN fibers were *** method for analyzing the void structure developed in this study is useful for analyzing voids over with larger size range,as well as the effect of the void structure on the mechanical performance of fibers.

关键词： Polyacrylonitrile(PAN)fiber,Void structure Ultra-small angle X-ray scattering Small angle X-ray scattering Mechanical performance

Formation and growth of precipitates in a Mg-7Gd-5Y-1Nd-2Zn-0.5Zr alloy aged at 200℃

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镁合金学报(英文) 2023年第7期11卷 2326-2339页

作者： Zhiwei Du Yonggang Peng Hang Teng Zhong Cao Kui Zhang Minglong Ma xiaolei Han Ting Li Cong che.Yongjun Li Guobiao(Beijing)Testing&Certification Co. Ltd.Beijing 100088China China United Test&Certification Co. Ltd.Beijing 100088China Nanjing Yunhai Special Metal Co. Ltd.Nanjing 211212China Shanghai Spaceflight Precision Machinery Institute Shanghai 201600China State Key Laboratory of Non-Ferrous Metals&Processes GRIMAT Engineering Institute Co.Ltd.Beijing 101407China

Crystal structures,growth characteristics,and transformation of the precipitates in a Mg-7Gd-5Y-1Nd-2Zn-0.5Zr(wt.%)alloy aged at 200℃for various durations were investigated using transmission electron microscopy(TEM)and high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM).A detailed Mg-Gd type precipitation sequence for Mg-Gd-Y-Nd-Zn alloys was proposed as follows:supersaturated solid solution→solute clusters→zigzag GP zones+β''(I)→β'→β'+protrusions/joints→pre-β_(1)→β_(1)→β.Solute clusters formed in the early stage of aging consisted of one or more rare-earth(RE)/Zn-rich atomic columns with different ***/Zn-rich solute clusters grew into zigzag GP zones andβ''(I)as aging time *** paired-zigzag GP zones might grow up to beβ'precipitates *** the peak-and plat-aging stages,the number of solute clusters in the matrix decreased until they disappeared,and most existed as zigzag arrays and super *** formed at the end ofβ'at an angle of 120°,then grew into joints when two differentβ'variants encountered ***/joints comprise zigzag arrays,super-hexagons,β'F,β''(II),β_(T),and hybrid structures rich in solute atoms,and act as catalysts for the growth of theβ'***β'grow by joints consumption while smallerβ'precipitates dissolve to form joints.β_(1)precipitates essentially evolve from pre-β_(1)precipitates,with four-point diamond structures formed by RE/Zn atomic substitution and atomic migration based on the originalα-Mg structure.

关键词： Magnesium alloys Aging Precipitates Microstructures HAADF-STEM

SDF-1/CXCR4 axis modulates bone marrow mesenchymal stem cell apoptosis, migration and cytokine secretion

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Protein & Cell 2011年第10期2卷 845-854页

作者： xiaolei Liu Biyan Duan Zhaokang che.g Xiaohua Jia Lina Mao Hao Fu Yongzhe che.Lailiang Ou Lin Liu Deling Kong The Key Laboratory of Bioactive Materials Ministry of EducationCollege of Life ScienceNankai UniversityTianjin 300071China College of Pharmacy Nankai UniversityTianjin 300071China School of Medicine Nankai UniversityTianjin 300071China Current address:Oklahoma Medical Research Foundation Oklahoma CityOK 73104USA

Bone marrow mesenchymal stem cells(MSCs)are considered as a promising cell source to treat the acute myocardial ***,over 90%of the stem cells usually die in the first three days of *** potential,migration ability and paracrine capacity have been considered as the most important three factors for cell transplantation in the ische.ic cardiac *** hypothesized that stromal-derived factor-1(SDF-1)/CXCR4 axis plays a critical role in the regulation of these *** this study,apoptosis was induced by exposure of MSCs to H2O2 for 2 *** re-oxygenation,the SDF-1 pretreated MSCs demonstrated a significant increase in survival and ***-1 pretreatment also enhanced the migration and increased the secretion of pro-survival and angiogenic cytokines including basic fibroblast growth factor and vascular endothelial growth *** blot and RT-PCR demonstrated that SDF-1 pretreatment significantly activated the pro-survival Akt and Erk signaling pathways and up-regulated Bcl-2/Bax *** protective effects were partially inhibited by AMD3100,an antagonist of *** conclude that the SDF-1/CXCR4 axis is critical for MSC survival,migration and cytokine secretion.

关键词： SDF-1/CXCR4 bone marrow mesenchymal mesenchymal stem cells survival migration secretion

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贵州关岭:关岭模式带动山区脱贫和生态改善

中国水利 2009年第7期 68-70页

作者：车小磊《中国水利》记者

石漠化是岩溶区水土流失、生态恶化的极端表现形式。它以岩石越来越裸露为基本特征．其结果是自然生态环境退化，人类生存环境恶化。石漠化与贫闲是一对孪生兄弟，石漠化地区的水土流失不仅是严重的自然灾害，而且已成为一个严峻的生态... 详细信息

石漠化是岩溶区水土流失、生态恶化的极端表现形式。它以岩石越来越裸露为基本特征．其结果是自然生态环境退化，人类生存环境恶化。石漠化与贫闲是一对孪生兄弟，石漠化地区的水土流失不仅是严重的自然灾害，而且已成为一个严峻的生态安全和社会问题。2007年，国务院批复《岩溶地区石漠化综合治理规划大纲》，在全国确定了100个石漠化综合治理试点县，贵州省有包括关岭自治县在内的55个县被纳入了试点范围，关岭县也被贵州列为全省喀斯特石漠化综合治理示范县。

关键词：贵州关岭生态改善综合治理规划石漠化地区脱贫山区生态环境退化喀斯特石漠化

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民生水利惠滨州

中国水利 2009年第13期 3-4,30页

作者：车小磊《中国水利》编辑部

滨州市位于山东省北部，是黄河三角洲的中心城市，也是鲁北的粮棉之乡。近年，滨州市主要经济指标增幅在山东省名列前茅。之所以有如此快速的发展，很重要的是得益于水。用滨州市市委副书记、市长张光峰的话说：“水是滨州的灵魂．滨州... 详细信息

滨州市位于山东省北部，是黄河三角洲的中心城市，也是鲁北的粮棉之乡。近年，滨州市主要经济指标增幅在山东省名列前茅。之所以有如此快速的发展，很重要的是得益于水。用滨州市市委副书记、市长张光峰的话说：“水是滨州的灵魂．滨州的发展离不开水，滨州人民离不开水。”

关键词：滨州市水利黄河三角洲中心城市经济指标山东省开水

The expression of estrogen receptors in thyroid cancer and its significance

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Oncology and Translational Medicine 2017年第3期3卷 127-130页

作者： Yuxuan che.Huamin Qin xiaolei Ding Xiuhua Sun Lifen Wang Medical Oncology Department The Second Affiliated Hospital Dalian Medical University Dalian 116027 China Pathology Department The Second Affiliated Hospital Dalian Medical University Dalian 116027 China

Objective The study aimed to detect the expression of estrogen receptors(ERs) in thyroid cancer and investigate the correlation between their expression and clinical features and different pathological *** The expression of ERs in 56 samples of thyroid cancer tissues was detected by an immunoche.ical approach. The expression of ERs in thyroid cancer tissues and different pathological types were analyzed using the χ~2 test. Results The number of cases with positive expression of ER in thyroid cancer tissues was 36. The number of papillary thyroid cancers(PTCs) was 48, with positive expression of ERs in 32 cases. The number of follicular thyroid cancers was 4, with positive expression of ERs in 2 cases. The number of medullary thyroid cancers was 4, with negative expression of ERs in all cases. The difference between the expression and different pathological types showed statistical significance. The expression of ERs showed no correlation with sex, age, or TNM stage, with no statistical significance. However, the expression of ERs was correlated with metastasis of lymph nodes, which had statistical significance. The expression of ERs was negatively correlated with pathological types and metastasis of lymph nodes. The correlated coefficient index was –0.313 and –0.334, respectively. Conclusion The expression of ERs showed no correlation with sex, age, or TNM stage, but was negatively correlated with pathological types and metastasis of lymph nodes.

关键词： thyroid cancer estrogen receptor(ER) pathological type

A bio-inspired O2-tolerant catalytic CO2 reduction electrode

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Science Bulletin 2019年第24期64卷 1890-1895页

作者： Xu Lu Zhan Jiang xiaolei Yuan Yueshen Wu Richard Malpass-Evans Yiren Zhong Yongye Liang Neil BMcKeown Hailiang Wang Department of che.istry Yale UniversityNew HavenCT 06520USA Energy Sciences Institute Yale UniversityWest HavenCT 06516USA Department of Materials Science and Engineering Shenzhen Key Laboratory of Printed Organic ElectronicsSouthern University of Science and TechnologyShenzhen 518055China Institute of Functional Nano and Soft Materials Jiangsu Key Laboratory for Carbon-Based Functional Materiab and DevicesSoochow UniversitySuzhou 215123China Eastche. School of ChemistryUniversity of EdinburghEdinburgh EH93FJUK

The electroche.ical reduction of CO2 to give CO in the presence of O2 would allow the direct valorization of flue gases from fossil fuel combustion and of CO2 captured from air. However, it is a challenging task because O2 reduction is thermodynamically favored over that of CO2. 5% O2 in CO2 near catalyst surface is sufficient to completely inhibit the CO2 reduction reaction. Here we report an O2-tolerant catalytic CO2 reduction electrode inspired by part of the natural photosynthesis unit. The electrode comprises of heterogenized cobalt phthalocyanine molecules serving as the cathode catalyst with >95% Faradaic efficiency(FE) for CO2 reduction to CO coated with a polymer of intrinsic microporosity that works as a CO2-selective layer with a CO2/O2 selectivity of $20. Integrated into a flow electrolytic cell, the hybrid electrode operating with a CO2 feed gas containing 5% O2 exhibits a FECOof 75.9% with a total current density of 27.3 mA/cm^2 at a cell voltage of 3.1 V. A FECO of 49.7% can be retained when the O2 fraction increases to 20%. Stable operation for 18 h is demonstrated. The electroche.ical performance and O2 tolerance can be further enhanced by introducing cyano and nitro substituents to the phthalocyanine ligand.

关键词： Electroche.ical CO2 reduction O2 tolerance Gas separation Polymer of intrinsic microporosity Cooperative catalysis