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时效温度对Ti-35Nb-5Ta-7Zr合金α相特征及力学性能和腐蚀行为的影响
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作者 王浩楠 和正华 +5 位作者 张思倩 庞雯露 周舸 张浩宇 朱晓飞 陈立佳 《材料热处理学报》 CAS CSCD 北大核心 2024年第10期68-79,共12页
利用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、纳米压痕以及电化学测试等研究了时效温度对Ti-35Nb-5Ta-7Zr合金α相的数量、尺寸与分布特征以及力学性能和腐蚀行为的影响。结果表明:在400~450℃时效处理后,大量针状α相优先在晶... 利用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、纳米压痕以及电化学测试等研究了时效温度对Ti-35Nb-5Ta-7Zr合金α相的数量、尺寸与分布特征以及力学性能和腐蚀行为的影响。结果表明:在400~450℃时效处理后,大量针状α相优先在晶界位置析出,并随温度升高呈网状结构;在超过500℃时效处理后,α相进一步长大,呈三角特征且分布均匀。合金的强度与弹性模量随时效温度升高呈现先升高再降低的趋势,在450℃时达到峰值,断后伸长率随时效温度升高逐渐提高。由此可见,合金强度、塑性与弹性模量随时效温度的变化与α相数量、尺寸和分布特征密切相关。随着时效温度的升高,Ti-35Nb-5Ta-7Zr合金在模拟体液中的耐蚀性呈现先降低后升高的趋势。分析可知,400~450℃时效时,富Ti而少Nb、Zr的针状α相在晶界与晶内析出,因其与基体存在电位差形成原电池,故针状α相数量增加导致耐蚀性降低;时效温度超过500℃时,α相在晶界与晶内均匀析出,降低了局部腐蚀倾向,促进均匀钝化膜的形成而提升耐蚀性。 展开更多
关键词 生物医用钛合金 Α相 力学性能 腐蚀行为
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Mn和B对Al-Si合金中Fe相组织的影响
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作者 王家伟 席赟 +2 位作者 王连超 李亨 陈星 《安徽工程大学学报》 CAS 2024年第4期43-51,共9页
研究Mn、B以中间合金形式加入铝液中对Al-Si合金中Fe相组织的影响。此次研究中,在熔体中加入0.625~2.5 wt.%的Mn和1~3 wt.%的Al-8%B中间合金进行保温沉降,因此合金的底部形成了块状α-Al(FeMn)Si相和AlB_(2)相沉淀,从而达到除铁的目的... 研究Mn、B以中间合金形式加入铝液中对Al-Si合金中Fe相组织的影响。此次研究中,在熔体中加入0.625~2.5 wt.%的Mn和1~3 wt.%的Al-8%B中间合金进行保温沉降,因此合金的底部形成了块状α-Al(FeMn)Si相和AlB_(2)相沉淀,从而达到除铁的目的。Mn有利于块状富Fe相粒径的增大,加速沉降;AlB_(2)相会促进Mn在固液界面前沿析出,有利于富Fe相的形成。在温度为630~640℃时,具有较大的过冷度,铝液黏度较低,更有利于富Fe相的沉降。当Mn/Fe为2,Al-8%B的添加量为2 wt.%时为最佳合金设计。在630℃时铁含量降至0.5 wt.%,除铁率为60%,且保持较低的Mn含量。 展开更多
关键词 Mn/Fe α-Al(FeMn)Si相 保温温度 AlB_(2)
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孔隙和α-Al(Fe/Mn)Si相对高压压铸Al-7Si-0.2Mg合金塑性的影响
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作者 杨雨童 黄诗尧 +4 位作者 郑江 杨莉 程晓农 陈睿凯 韩维建 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第2期378-391,共14页
采用高压压铸工艺制备两批次不同尺寸的Al-7Si-0.2Mg(质量分数,%)合金,获得显微组织和孔隙非均匀分布的薄壁铸件,并对比研究孔隙和显微组织对铸态合金塑性的影响。结果表明:不同铸件和不同位置样品的伸长率有较大波动(9.7%~17.9%)。当... 采用高压压铸工艺制备两批次不同尺寸的Al-7Si-0.2Mg(质量分数,%)合金,获得显微组织和孔隙非均匀分布的薄壁铸件,并对比研究孔隙和显微组织对铸态合金塑性的影响。结果表明:不同铸件和不同位置样品的伸长率有较大波动(9.7%~17.9%)。当合金存在大面积孔隙时,有效承载面积减小导致由孔隙产生的应力集中使合金伸长率显著降低。当合金只存在小面积孔隙时,塑性变形过程中合金中的α-Al(Fe/Mn)Si相先于共晶硅相发生脆性断裂,α-Al(Fe/Mn)Si相的数量密度对伸长率的波动起主导作用,具有高数量密度α-Al(Fe/Mn)Si相试样的伸长率显著降低。此外,局部较高的冷却速率导致铸件α-Al(Fe/Mn)Si相数量密度的增加。 展开更多
关键词 高压压铸 Al-7Si-0.2Mg合金 孔隙 α-Al(Fe/Mn)Si相 塑性
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分散固相萃取/荧光检测法选择性富集和定量人体血浆中的α-细辛醚
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作者 唐芃 刘铁 刘德龙 《分析测试学报》 CAS CSCD 北大核心 2024年第3期432-439,共8页
该研究采用基于共价有机框架TpBD-Me_(2)(COF-TpBD-Me_(2))的分散固相萃取/荧光检测法对人体血浆中的α-细辛醚进行选择性富集和定量检测。优化了COF-TpBD-Me_(2)对α-细辛醚的最佳吸附条件,包括吸附剂质量浓度、吸附时间、pH值、解吸... 该研究采用基于共价有机框架TpBD-Me_(2)(COF-TpBD-Me_(2))的分散固相萃取/荧光检测法对人体血浆中的α-细辛醚进行选择性富集和定量检测。优化了COF-TpBD-Me_(2)对α-细辛醚的最佳吸附条件,包括吸附剂质量浓度、吸附时间、pH值、解吸试剂和解吸时间。此外,还通过吸附等温线和吸附动力学实验阐明了吸附行为和机理。α-细辛醚在0.1~10µg/mL范围内呈良好的线性关系,相关系数(r^(2))大于0.999,检出限(LOD)为0.0025µg/mL。该方法对人体血浆中α-细辛醚的加标回收率为92.2%~98.0%,相对标准偏差为1.9%~3.8%。实验结果证明所建方法可选择性富集人体血浆中的α-细辛醚并实现准确定量。该方法为选择性富集和快速定量复杂生物基质中的药物活性成分提供了参考。 展开更多
关键词 共价有机框架 分散固相萃取 吸附 Α-细辛醚 荧光检测
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基于多重扫描速率法的α-Al_(2)O_(3)煅烧动力学研究
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作者 邹婷 李中林 +4 位作者 王丁 吕凤程 张伟光 李义兵 蒋学先 《矿冶工程》 CAS 北大核心 2024年第2期106-111,共6页
以氢氧化铝粉体为原料,探究氢氧化铝煅烧为α-Al_(2)O_(3)过程中的相转变与微观组织变化,利用多重扫描速率法对其煅烧过程进行动力学模拟计算。结果表明,氢氧化铝煅烧为α-Al_(2)O_(3)的优化条件为:煅烧温度1200℃、煅烧时间2 h、升温速... 以氢氧化铝粉体为原料,探究氢氧化铝煅烧为α-Al_(2)O_(3)过程中的相转变与微观组织变化,利用多重扫描速率法对其煅烧过程进行动力学模拟计算。结果表明,氢氧化铝煅烧为α-Al_(2)O_(3)的优化条件为:煅烧温度1200℃、煅烧时间2 h、升温速率5℃/min。氢氧化铝煅烧过程出现3个吸热峰,对应3个失重阶段:第一阶段反应机理函数为G(α)=[(1-α)^(-1/3)-1]^2,反应平均活化能为91.16 kJ/mol,指前因子17.00×10^(9)~44.03×10^(9)min^(-1);第二阶段反应机理函数为G(α)=α~2,反应平均活化能为106.2 kJ/mol,指前因子7.70×10^(9)~18.60×10^(9)min^(-1);第三阶段反应机理函数为G(α)=α~(1/4),反应平均活化能为235.42 kJ/mol,指前因子39.94×10^(9)~50.79×10^(9)min^(-1)。 展开更多
关键词 氢氧化铝 氧化铝 煅烧 相变 α-Al_(2)O_(3) 热分析 动力学 多重扫描速率法
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半干法制备千克量级α-半水石膏粉及工艺能耗计算
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作者 胡增来 胡勇 +4 位作者 杜本康 王训彦 王海洋 曹宏 赵明星 《云南化工》 CAS 2024年第2期26-30,共5页
以磷石膏、脱硫石膏为原料,采用半干法工艺实现α-半水石膏粉千克量级制备试验,采用SEM场发射扫描电镜和马尔文激光粒度仪分析α-半水石膏粉形貌和粒径分布,对两种α-半水石膏粉物相组成分析和力学性能强度进行对比。结果表明:两种α-... 以磷石膏、脱硫石膏为原料,采用半干法工艺实现α-半水石膏粉千克量级制备试验,采用SEM场发射扫描电镜和马尔文激光粒度仪分析α-半水石膏粉形貌和粒径分布,对两种α-半水石膏粉物相组成分析和力学性能强度进行对比。结果表明:两种α-半水石膏粉中半水石膏相转化率在90%左右,晶体长径比接近于1,磷石膏基α-半水石膏粉力学性能最佳,其2 h抗折强度2.6 MPa,绝干抗压强度13.6 MPa。计算半干法工艺能耗,与传统煅烧法对比能耗降低约29.5%,工艺简单、绿色化,证明半干法工艺量产制备α-半水石膏粉在工业上可行性,为大规模消耗利用化学石膏提供科学基础。 展开更多
关键词 Α-半水石膏 半干法 千克量级 相组成 力学性能 能耗
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α-Fe_(2)O_(3)/g-C_(3)N_(4)复合物的合成及光催化还原Cr(Ⅵ)的实验设计 被引量:2
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作者 张永才 侯振华 +2 位作者 吴迪 毕昌军 侯建华 《实验室研究与探索》 CAS 北大核心 2023年第9期6-11,共6页
为解决赤铁矿(α-Fe_(2)O_(3))和石墨相氮化碳(g-C_(3)N_(4))光催化活性低的问题,设计了一种采用液固混合-焙烧制取α-Fe_(2)O_(3)/g-C_(3)N_(4)复合光催化剂的方法。通过在可见光照射下光催化还原Cr(Ⅵ)实验研究合成的α-Fe_(2)O_(3)/g... 为解决赤铁矿(α-Fe_(2)O_(3))和石墨相氮化碳(g-C_(3)N_(4))光催化活性低的问题,设计了一种采用液固混合-焙烧制取α-Fe_(2)O_(3)/g-C_(3)N_(4)复合光催化剂的方法。通过在可见光照射下光催化还原Cr(Ⅵ)实验研究合成的α-Fe_(2)O_(3)/g-C_(3)N_(4)复合物的光催化性能,并通过光电化学性能测试及能带结构分析探究其光催化活性增大的原因。结果表明:所合成的α-Fe_(2)O_(3)/g-C_(3)N_(4)复合物具有显著优于α-Fe_(2)O_(3)和g-C_(3)N_(4)的光催化活性,其光催化还原Cr(Ⅵ)的反应速率常数(k)为0.026 min^(-1),分别是g-C_(3)N_(4)(k=0.004 min^(-1))的6.5倍和α-Fe_(2)O_(3)(k=0.003 min^(-1))的8.7倍;α-Fe_(2)O_(3)/g-C_(3)N_(4)复合物为Ⅰ型异质结,能有效提高光生空穴与电子的分离及转移效率,是导致其光催化活性升高的原因。所设计的合成方法简单易行、成本低且合成的α-Fe_(2)O_(3)/g-C_(3)N_(4)复合物光催化还原Cr(Ⅵ)性能好,为Cr(Ⅵ)废水处理开发了一种有应用潜力的可见光催化剂。 展开更多
关键词 赤铁矿 石墨相氮化碳 复合物 光催化 六价铬还原
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PHASE EQUILIBRIA OF α_2(α)/γ IN Ti-Al-Nb TERNARY SYSTEM 被引量:1
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作者 Ding Jinjun, Zhao Gang, Hao Shiming Department of Materials Science and Engineering School of Materials and Metallurgy, Northeastern University, Shenyang 110006 《中国有色金属学会会刊:英文版》 CSCD 1997年第4期21-24,共4页
PHASEEQUILIBRIAOFα2(α)/γINTiAlNbTERNARYSYSTEM①DingJinjun,ZhaoGang,HaoShimingDepartmentofMaterialsSciencean... PHASEEQUILIBRIAOFα2(α)/γINTiAlNbTERNARYSYSTEM①DingJinjun,ZhaoGang,HaoShimingDepartmentofMaterialsScienceandEngineringSchool... 展开更多
关键词 Ti Al Nb TERNARY SYSTEM diffusion COUPLE α 2(α)/γ phase EQUILIBRIA
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Syntheses of α-Hydroxyarylacetic Acids in the Presence of Different Phase Transfer Catalysts Under Sonication 被引量:1
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作者 XU Wei-liang 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2001年第2期175-177,共3页
The syntheses of α-hydroxyarylacetic acids with a good yield in the presence of different phase transfer catalysts (PTC) under sonication were studied. The results obtained are superior to those by other similar met... The syntheses of α-hydroxyarylacetic acids with a good yield in the presence of different phase transfer catalysts (PTC) under sonication were studied. The results obtained are superior to those by other similar methods. The data show that β-cyclodextrin (β-CD) is more efficient than other PTC. The preliminary reaction conditions are also discussed. 展开更多
关键词 α-Hydroxyarylacetic acid phase transfer catalyst Sonication
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Synthesis of YAG∶Ce^(3+) Phosphor by Polyacrylamide Gel Method and Promoting Action of α-Al_2O_3 Seed Crystal on Phase Formation 被引量:5
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作者 李永绣 李颖毅 +4 位作者 闵宇霖 吴燕利 程昌明 周雪珍 辜子英 《Journal of Rare Earths》 SCIE EI CAS CSCD 2005年第5期517-520,共4页
YAG: Ce^3 + phosphor particles were prepared using polyacrylamide gel method. The structure evolution of powders during annealing process was followed by X-ray diffraction determination. It is found that some interm... YAG: Ce^3 + phosphor particles were prepared using polyacrylamide gel method. The structure evolution of powders during annealing process was followed by X-ray diffraction determination. It is found that some intermediate phases, including θ-Al2O3, YAM and YAP, are formed when calcining polyacrylamide gel, however, the pure YAG phase can be formed directly when calcining polyacrylamide gel with α-Al2O3 as seed crystal. These facts show that the existence of α- Al2O3 seed crystal can block the formation of θ-Al2O3, YAM and YAP, and accelerate its reaction with Y2O3 to form YAG phase directly at lower temperature. The emission peak of prepared YAG : Ce^3 + phosphor is wide with maximum at 550 nm and the exitation band has two peaks, the major one is around at 460 nm, which matches the blue emission of GaN LED and is suitable for the assemble of white LED. Some fluxes can enhance the photoluminescence intensity of phosphor particles, that can be attributed both to the improvement of crystallization processes of YAG and to the stabilization of trivalence cerium ion in YAG:Ce^3 +. 展开更多
关键词 YAG Ce^3 phosphor polyacrylamide gel α-Al2O3 seed crystal phase formation rare earths
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EFFECTS OF DEFORMATION ON MICROSTRUCTURE AND σ-PHASE FORMATION IN Cr_(25)Ni_(20) STAINLESS STEEL
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作者 GAO Yan LI Dejun CAO Zhiben Dalian University of Science and Technology,Dalian,Liaoning,China LI Dejun,Lecturer,Department of Materials Engineering,Dalian University of Science and Technology,Dalian,Liaoning,China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1989年第2期157-159,共3页
The microstructure of Cr_(25)Ni_(20)stainless steel under plastic deformation up to 50% has re- vealed an even distributed twins,micro-twins and deformation bands.The σ-phase formation in 800℃ aged specimens is acce... The microstructure of Cr_(25)Ni_(20)stainless steel under plastic deformation up to 50% has re- vealed an even distributed twins,micro-twins and deformation bands.The σ-phase formation in 800℃ aged specimens is accelerated by its nucleation at either deformation twins or recrystallized grain boundaries under less or more deformation respectively.In the recrystallized zone,the recrystallization is prior to the precipitation of σ-phase.Although recrystallization may accelerate the formation of σ-phase,it is not essential.The twins and micro-twins produced by deformation may also provide the additional nucleation sites. 展开更多
关键词 plastic deformation α-phase RECRYSTALLIZATION
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α(α2)/γ PHASE EQUILIBRIA IN Ti-Al-C AND Ti-Al-B TERNARY SYSTEMS 被引量:1
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作者 Li Juntao, Hao Shiming Department of Materials Science and Engineering, Northeastern University, Shenyang 110006 《中国有色金属学会会刊:英文版》 CSCD 1997年第2期64-67,共4页
α(α2)/γPHASEEQUILIBRIAINTiAlCANDTiAlBTERNARYSYSTEMS①LiJuntao,HaoShimingDepartmentofMaterialsScienceandEn... α(α2)/γPHASEEQUILIBRIAINTiAlCANDTiAlBTERNARYSYSTEMS①LiJuntao,HaoShimingDepartmentofMaterialsScienceandEnginering,Northeas... 展开更多
关键词 Ti Al X(X=C B) TERNARY system PARTIALLY vertical section α(α 2)/γ phase EQUILIBRIUM
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Computer simulation on primary α-phase of Al-7%Si solidification structure
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作者 李荣德 杨秀英 +3 位作者 李润霞 李晨曦 李殿中 李强 《中国有色金属学会会刊:英文版》 EI CSCD 2003年第5期1128-1132,共5页
Finite difference method was used to calculate the macroscopic transportation phenomena(including temperature and concentration fields) of Al 7%Si(mass fraction) alloy. On the basis of the results,coupled with local a... Finite difference method was used to calculate the macroscopic transportation phenomena(including temperature and concentration fields) of Al 7%Si(mass fraction) alloy. On the basis of the results,coupled with local area magnification, the nucleation and growth of primary α phase of Al 7%Si were simulated. Relating the growth process of α phase of Al 7%Si alloy in space with structures of a sample section, the morphology and precipitating process of primary α phase of Al 7%Si alloy was simulated. The results are in good agreement with those obtained experimentally. 展开更多
关键词 铝硅合金 宏观转变 仿真 Α相 凝固结构
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Effects of Stretching Ratio and Temperature on Phase Transition of Melt-spun Poly(Vinylidene Fluoride) Fibers
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作者 张华 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2006年第4期53-55,共3页
The effects of stretching ratio and stretching temperature on pbase transition of melt-spun poly ( vinylidene fluoride ) fibers were investigated and analyzed by using scanning electron microscopy, wide angle X- ray... The effects of stretching ratio and stretching temperature on pbase transition of melt-spun poly ( vinylidene fluoride ) fibers were investigated and analyzed by using scanning electron microscopy, wide angle X- ray diffraction, differential scanning calorimetry and Fourier transfer infrared spectroscopy. The β phase exists in the as-spun fiber. The β phase content increases as the stretching ratio increases. When the stretching temperature is lower than 100 ℃ , enhancing temperature is good for the transition of phase a to ft. By contrast, when the stretching temperature is higher than 100 ℃ , enhancing temperature is unfavourable for the transition of phase a to β. Increasing the draw temperature increases the α-phase content. 展开更多
关键词 poly( vinylidene fluoride) MELT-SPUN β-phase crystal α-phase crystal
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X-ray diffraction study of effect of deposition conditions on α-β phase transition and stress evolution in sputter-deposited W coatings
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作者 王聪 Brault Pascal +2 位作者 Pineau Alain Plantin Pascale Thomann Anne-Lise 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第2期432-436,共5页
Pure W and W-Cu-W trilayer coatings were deposited on an Fe substrate by d.c. magnetron sputtering. The α-β phase evolution, intragranular stress evolution in sputter-deposited W layer were investigated by x-ray dif... Pure W and W-Cu-W trilayer coatings were deposited on an Fe substrate by d.c. magnetron sputtering. The α-β phase evolution, intragranular stress evolution in sputter-deposited W layer were investigated by x-ray diffraction. They are directly related to the film microstructure, density and adhesion. Therefore, control of the film stress and phase component transition is essential for its applications. The phase component transition from β-W to α-W and intragranular stress evolution from tensile to compressive strongly depend on the deposition parameters and can be induced by lowering Ar pressure and rising target power. The compressively stressed films with α-W phase have a dense microstructure and high adhesion to Fe substrate. 展开更多
关键词 W coatings x-ray diffraction α-β phase component transition thin film stress
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Synthesis of α-Aminoarylacetic Acids in the Presence of Phase Transfer Catalysts
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作者 Wei Liang XU You Fang CHEN Fei Long WU(Basic Course Division, Zhejiang Agricultural University, Hangzhou 310029) 《Chinese Chemical Letters》 SCIE CAS CSCD 1999年第10期813-816,共4页
Synthesis of aminoarylacetic acids with good yield in the presence of phase transfercatalyst (PTC) under sonication has been studied. Results obtained are superior to those by othersimilar methods. The data show that ... Synthesis of aminoarylacetic acids with good yield in the presence of phase transfercatalyst (PTC) under sonication has been studied. Results obtained are superior to those by othersimilar methods. The data show that cyclodextrin (5 -CD) is a more efficient catalyst thanother PTC. Optimum reaction conditions and a preliminary mechanism are also discussed. 展开更多
关键词 α-Aminoarylacetic acid phase transfer catalyst sonication.
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Analysis of α, β, γ-hexachlorocyclohexanes in water by novel activated carbon fiber-solid phase microextraction coupled with gas chromatography—mass spectrometry 被引量:4
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作者 SUNTong-hua FANGNeng-hu +2 位作者 ZHUNan-wen WANGYa-lin JIAJin-ping 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2004年第6期945-949,共5页
A fast and simple method for determination of α, β, γ-hexachlorocyclohexanes (HCHs) in water using activated carbon fiber-solid phase microextraction(ACF-SPME) were studied. Results showed the performance of adsorp... A fast and simple method for determination of α, β, γ-hexachlorocyclohexanes (HCHs) in water using activated carbon fiber-solid phase microextraction(ACF-SPME) were studied. Results showed the performance of adsorption and desorption of three HCHs on ACF were excellent. A wide linear range from 10 to 100 μg/L and detection limits of the ng/L level were obtained using ACF-SPME with GC-MS in selected ion monitoring(SIM) acquisition mode. The proposed method was also successfully applied for determination of three HCHs in tap water. Compared to commercial fibers, ACF showed some advantages such as better resistance to solvents, higher thermal stability, longer lifetime and lower cost. The data demonstrated that GC-MS with ACF-SPME is well suitable for the analysis of HCHs in water. 展开更多
关键词 solid phase microextraction activated carbon fiber residue analysis α β γ-hexachlorocyclohexanes GC-MS
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An Example of a Bounded Potential q(x) on the Half-Line, for Estimates of A(α) Amplitude
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作者 Herminio Blancarte 《Applied Mathematics》 2023年第2期130-149,共20页
We show an example of a bounded potential on the half-line obtained as the image of an Inverse Transformation Operator of the Bessel singular potential of the Reduced Radial Schr&#246;dinger Equation, and show us ... We show an example of a bounded potential on the half-line obtained as the image of an Inverse Transformation Operator of the Bessel singular potential of the Reduced Radial Schr&#246;dinger Equation, and show us the Estimates of the A(α) amplitude. 展开更多
关键词 The Amplitude A(α) as a Function of the phase α Estimates of the A(α) Amplitude A Bounded Potential on the Half Line
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Solid Phase Synthesis of 1,4-Disubstituted 1,2,3-Triazole from Polystyrene-supported Selenium Resin
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作者 Wei Ming XU Lu Ling WU Xian HUANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第5期603-605,共3页
We report here a solid-phase synthesis of 1, 4-disubstituted 1, 2, 3-triazole using polystyrene-supported selenium resin. The resin used here not only works as a simple linker, but also assists the crucial α-alkylati... We report here a solid-phase synthesis of 1, 4-disubstituted 1, 2, 3-triazole using polystyrene-supported selenium resin. The resin used here not only works as a simple linker, but also assists the crucial α-alkylation reaction and selenoxide syn-elimimation, which ensures the purity of the products. 展开更多
关键词 Solid-phase synthesis 1 3-dipolar cycloaddition α-alkylation reaction 1 2 3-triazole.
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浇注温度与型壳温度对K4648镍基高温合金组织和性能的影响
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作者 张丽辉 高达 +5 位作者 黄强 张楚博 张强 任晓冬 胡聘聘 张勇 《机械工程材料》 CAS CSCD 北大核心 2024年第6期75-80,共6页
针对某型号燃气涡轮导向器用K4648镍基高温合金室温冲击韧性无法达到标准要求(冲击韧性大于20 J·cm^(-2))的问题,在不同的浇注温度与型壳温度(1 490℃/1 050℃,1 490℃/950℃,1 460℃/1 050℃)下制备了K4648镍基高温合金,并进行了... 针对某型号燃气涡轮导向器用K4648镍基高温合金室温冲击韧性无法达到标准要求(冲击韧性大于20 J·cm^(-2))的问题,在不同的浇注温度与型壳温度(1 490℃/1 050℃,1 490℃/950℃,1 460℃/1 050℃)下制备了K4648镍基高温合金,并进行了固溶+标准热处理,研究了浇注温度与型壳温度对合金显微组织和冲击性能的影响,获得了优化的工艺参数。结果表明:当型壳温度或浇注温度较低时,K4648镍基高温合金的晶粒尺寸和二次枝晶间距较小,块状初生α-Cr相含量较少、尺寸较小,合金的冲击韧性较大,冲击断口处次生裂纹数量较少;优化工艺参数为型壳温度950℃、浇注温度1 490℃,此工艺参数下制备的K4648镍基高温合金的冲击韧性最大,为21.4 J·cm^(-2),满足标准要求。 展开更多
关键词 K4648镍基高温合金 浇注工艺 Α-CR相 冲击韧性
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