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High temperature oxidation behavior of high speed steel for hot rolls material 被引量:1
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作者 lizhou FangLiu +2 位作者 ChangshengLiu DaleSun LisongYao 《Journal of University of Science and Technology Beijing》 CSCD 2005年第2期166-171,共6页
The oxidation characteristics of high speed steel (HSS) were studied at 500 to 800°C. The non-isothermal oxidation and isothermal oxidation (500, 575, 650, 725, 800°C) of HSS were investigated by thermo-gra... The oxidation characteristics of high speed steel (HSS) were studied at 500 to 800°C. The non-isothermal oxidation and isothermal oxidation (500, 575, 650, 725, 800°C) of HSS were investigated by thermo-gravimetric analysis (TGA). The microstruc- ture, morphology and oxide scale thickness of the isothermal oxidation samples were analyzed by optical microscope (OM), electron probe micro analyzer (EPMA), X-ray diffraction spectrum (XRD) and scanning electron microscope (SEM). The results indicate that the oxidation rate of HSS is very slow at 500 to 650°C, increasing gradually at 650 to 750°C, and drastically at 750 to 800°C, be- cause the phase transformation happens at about 750°C. 展开更多
关键词 high speed steel high temperature oxidation isothermal oxidation non-isothermal oxidation oxide kinetics
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含1,2,4-三唑并[3,4-b]-1,3,4-噻二唑杨梅素衍生物的设计、合成及生物活性研究
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作者 王启帆 张源泉 +6 位作者 幸丽 周远香 龚晨裕 何帮灿 张念 吴拥军 薛伟 《有机化学》 SCIE CAS CSCD 北大核心 2023年第4期1525-1536,共12页
利用活性拼接的原理,以杨梅苷为原料,将1,2,4-三唑并[3,4-b]-1,3,4-噻二唑引入到杨梅素结构中,合成了一系列含三唑并噻二唑的杨梅素衍生物,通过1H NMR、13C NMR和高分辨质谱(HRMS)进行了结构表征,并通过X单晶衍射实验确认了3-(3-((3-乙... 利用活性拼接的原理,以杨梅苷为原料,将1,2,4-三唑并[3,4-b]-1,3,4-噻二唑引入到杨梅素结构中,合成了一系列含三唑并噻二唑的杨梅素衍生物,通过1H NMR、13C NMR和高分辨质谱(HRMS)进行了结构表征,并通过X单晶衍射实验确认了3-(3-((3-乙基-[1,2,4]三唑[3,4-b][1,3,4]噻二唑-6-基)硫代)丙氧基)-5,7-二甲氧基-2-(3,4,5-三甲氧基苯基)-4H-色酮-4-酮(A5)的结构.生物活性测试结果表明:浓度为100μg/mL时,3-(3-((3-(4-(叔丁基)苯基)-[1,2,4]三唑[3,4-b][1,3,4]噻二唑-6-基)硫基)丙氧基)-5,7-二甲氧基-2-(3,4,5-三甲氧基苯基)-4H-色酮-4-酮(A15)对柑桔溃疡病菌(Xac)的抑制率为63.3%,优于对照药噻菌铜(57.3%);部分化合物对烟草花叶病毒(TMV)表现出较好的抑制活性.其中,治疗活性方面,化合物A5,5,7-二甲氧基-3-(4-((3-(甲氧基甲基)-[1,2,4]三唑[3,4-b][1,3,4]噻二唑-6-基)硫代)丁氧基)-2-(3,4,5-三甲氧基苯基)-4H-色酮-4-酮(A8),5,7-二甲氧基-3-(3-((3-苯基-[1,2,4]三唑[3,4-b][1,3,4]噻二唑-6-基)硫代)丙氧基)-2-(3,4,5-三甲氧基苯基)-4H-色酮-4-酮(A9),5,7-二甲氧基-3-(4-((3-(对甲苯基)-[1,2,4]三唑[3,4-b][1,3,4]噻二唑-6-基)硫代)丁氧基)-2-(3,4,5-三甲氧基苯基)-4H-色酮-4-酮(A12)的EC50值分别为88.3,139.1,109.9,160.1μg/mL,优于对照药宁南霉素(227.2μg/mL).保护活性方面,5,7-二甲氧基-3-(4-((3-苯基-[1,2,4]三唑[3,4-b][1,3,4]噻二唑-6-基)硫代)丁氧基)-2-(3,4,5-三甲氧基苯基)-4H-色酮-4-酮(A10),5,7-二甲氧基-3-(4-((3-(4-甲氧基苯基)-[1,2,4]三唑[3,4-b][1,3,4]噻二唑-6-基)硫基)丁氧基)-2-(3,4,5-三甲氧基苯)-4H-色酮-4-酮(A14),3-(3-((3-(4-(叔丁基)苯基)-[1,2,4]三唑[3,4-b][1,3,4]噻二唑-6-基)硫基)丙氧基)-5,7-二甲氧基-2-(3,4,5-三甲氧基苯基)-4H-色酮-4-酮(A15),3-(4-((3-(4-叔丁基)苯基)-[1,2,4]三唑[3,4-b][1,3,4]噻二唑-6-基)硫基)丁氧基)-5,7-二甲氧基-2-(3,4,5-三甲氧基苯基)-4H-色酮-4-酮(A16),3-(4-((3-(4-氯苯基)-[1,2,4]三唑[3,4-b][1,3,4]噻二唑-6-基)硫基)丁氧基)-5,7-二甲氧基-2-(3,4,5-三甲氧基苯基)-4H-色酮-4-酮(A18)的EC50值分别为103.1,107.4,86.3,79.2,111.5μg/mL,优于对照药宁南霉素(179.2μg/mL).微量热涌动实验表明,化合物A12和A16与烟草花叶病毒外壳蛋白(TMV-CP)具有较强的亲和力,分子对接实验表明,化合物A16与TMV-CP具有较强的相互作用. 展开更多
关键词 杨梅素衍生物 1 2 4-三唑并[3 4-b]-1 3 4-噻二唑 生物活性 晶体结构 病毒蛋白
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Public Goods, Environmental Protection,and the Development Paradigm in Rural China
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作者 lizhou 《China & World Economy》 SCIE 2004年第6期86-97,共12页
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