Microstructure and electrical properties of 3Y-TZP/Al2O3 composite obtained using the citrate gel method

3Y-TZP sinters with 1, 5, 10, and 15 mol% of Al₂O₃ were prepared using two different procedures from a 3-YSZ powder synthesized via the citrate process. In the first procedure, alumina was introduced during synthesis via the citrate method. In the second one, the 3-YSZ powder was impregnated with aluminum nitrate. All samples were sintered at 1773 K. The prepared composites were evaluated in terms of their microstructure, chemical and phase composition, and electrical properties. The total conductivity of the 3Y-TZP/Al₂O₃ composite material, which contained primarily the tetragonal phase, was found to increase with temperature, and to decrease for reduced concentrations of alumina in 3Y-TZP. In the case of the samples which had alumina introduced via impregnation, its higher content was not associated with significantly lower electrical conductivity. These samples generally exhibited higher conductivity than the samples to which alumina had been added via chemical synthesis.     

3-氯哒嗪的合成

以3,6-二氯哒嗪为原料,与10%的氢氧化钠溶液在110℃下反应生成3-羟基-6-氯哒嗪,经钯碳催化脱氯得到3-羟基哒嗪,再与三氯氧磷在80℃下回流,制得目标化合物3-氯哒嗪,总收率54.1%,其结构经1H NMR分析确认。     

3-(3’-戊基醚)-1,4-环己二烯-1-羧酸乙酯的合成

采用3-硝基丙烯酸乙酯和1,3-丁二烯基-3-戊基醚为原料,通过一个Diels-Alder反应和硝基消除反应以两步54%的总产率顺利地合成了3-(3’-戊基醚)-1,4-环己二烯-1-羧酸乙酯化合物。     

间羟基三氟甲苯的合成

以三氟甲苯为原料，经硝化、还原、重氮化、水解等过程，可以提到重要的农药中间体间羟基三氟甲苯，产物总收率达70％以上，在较高温度下进行重氮化反应时，可以显著提高间氨基三氟甲苯重氮化、水解反应的收率。     

3-[3-(1-哌啶甲基)苯氧基]丙胺的合成工艺改进

以间羟基苯甲醛为起始原料，经由氧烷基化、缩合、水解得3-[3-(1-哌啶甲基)苯氧基]丙胺，收率49．1％，结构经NMR确证。     

间羟基三氟甲苯的合成

以三氟甲苯为原料，经硝化、还原、重氮化、水解等过程，可以得到重要的农药中间体间羟基三氟甲苯，产物总收率达70％以上，在较高温度下进行重氮化反应时，可以显著提高间氨基三氟甲苯重氮化、水解反应的收率。     

Microwave-assisted hydrothermal synthesis of Eu2O3-coated spherical Y2O3 ceramic particles

This paper reports on the synthesis of uncoated and Eu₂O₃-coated spherical Y₂O₃ ceramic particles using optimized hydrothermal (HM) and microwave-assisted hydrothermal (MWHM) routes. The integration of microwave and hydrothermal processes was shown to enhance the reaction kinetics during the synthesis of uncoated Y₂O₃. Spherical particles of pure Y₂O₃ phase with an average particle size of 600 nm and uniform size distribution were obtained via the MWHM process at 180 °C following reaction duration of only 1 h. Y₂O₃ spherical particles were coated with Eu₂O₃ via a hydrolysis method at room temperature. The band gap of the resulting phosphors was estimated at 5.7 eV. Eu₂O₃-coated Y₂O₃ particles synthesized via the HM and MWHM present bright red PL emission under UV excitations; however, Y₂O₃ particles obtained via the MWHM method are more efficient than those yielded via the HM technique. Eu₂O₃-coated Y₂O₃ particles derived using the optimized MWHM technique present efficient emissions of red light with color purity and down conversion efficiency of approximately 85% and 80%, respectively. The present study demonstrates the suitability of employing coated phosphors in optical display technologies.     

Structure evolution,dielectric,and conductivity behavior of(K0.5Na0.5)NbO3-Bi(Zn2/3Nb1/3)O3 ceramics

(1-x)K0.5Na0.5NbO3-xBi(Zn2/3Nb1/3)O3 ((1-x)KNN-xBZN,x =0.010,0.015,0.020,0.025,and 0.030) lead-free ceramics were fabricated via a traditional solid-state metho...     

3-(2,8,9-三氧杂-5-氮杂-1-锗三环[3.3.3.0]十一烷基)-3-(4-羟基-3-甲氧基苯基)丙酸的合成

以氧化锗、次亚磷酸钠、浓盐酸为原料经氧化还原反应合成三氯锗仿,三氯锗仿再与阿魏酸经麦克尔加成反应得到3-三氯锗基-3-(4-羟基-3-甲氧基苯基)丙酸,然后与甲醇钠反应生成3-三甲氧锗基-3-(4-羟基-3-甲氧基苯基)丙酸,再与三乙醇胺发生烷基转移反应生成标题化合物.     

1-氯-3-甲氧基丙烷的合成

以丙烯腈为起始原料,经过与甲醇加成,氢化还原得到3-甲氧基-1-丙胺,继而用亚硝酸钠重氮化得到3-甲氧基-1-丙醇,用三氯化磷卤化得到目标产物1-氯-3-甲氧基丙烷,总收率68%。     

3-溴-6-甲基哒嗪的合成

以乙酰基丙酸、水合肼为原料,通过3步反应,高产率地合成了标题化合物,其结构经1HNMR和MS-ESI确证.该方法步骤短,收率高,是一种合成3-溴-6-甲基哒嗪的简捷方法.     

3-甲氨基哌啶二盐酸盐的合成

研究了巴洛沙星中间体3-甲氨基哌啶的合成工艺。以烟酰胺为起始原料,经Hofmann降解、甲酰化、LiAlH4还原、Na/EtOH还原和盐酸中和得标题化合物,总收率70%。用核磁共振氢谱对各步反应产物的结构进行了表征,用高效液相色谱分析了产品的纯度。     

聚丙烯／镧化合物改性超细碳酸钙复合材料的研究

采用熔融共混法制备了聚丙烯/镧化合物改性超细碳酸钙(PP/UCaCO3-La^3 )和聚丙烯/超细碳酸钙(PP/UCaCO3)两种复台材料.力学性能测试表明：复合材料的冲击强度随着填料用量的增加先增后减，拉伸强度则递减.PP/UCaCO3-La^3 的冲击强度高于PP/UCaCO3，可提高至PP的3倍以上?透射电镜和扫描电镜分析表明：UCaCO3-La^3 在PP中具有很好的分散性，随着镧化合物用量的增加而进一步改善.DSC分析表明，UCaCO3-La^3 可显著提高复合材料的结晶温度和结晶度，结晶性能的改善是材料冲击强度提高的重要原因.热重分析结果表明：与UCaCO3相比，UCaCO3-La^3 对提高PP热稳定性的贡献更为显著.     

3-苯甲酰基苯乙腈单甲基化的研究

以3-苯甲酰基苯乙腈为原料,采用碳酸二甲酯进行α-甲基化反应制备2-(3苯甲酰基苯基)丙腈,使反应控制在单甲基化阶段,HPLC测定产物含量99.7%。同时探讨了催化剂的选择、反应温度、反应时间对反应的影响。     

纳米CaSiO_3填料的制备及其性能表征

以乙醇为溶剂,正硅酸乙酯(TEOS)为胶溶剂,CaCO3为主要试剂,采用溶胶-凝胶(Sol-Gel)技术制备纳米偏硅酸钙(CaSiO3)填料,考察主要工艺参数——初始水凝胶pH值、R值(H2O/TEOS)对粉体形貌、颗粒大小等性质的影响。研究表明:采用溶胶-凝胶法能合成纳米级的CaSiO3填料。     

Tm~(3+)/Ho~(3+)/Yb~(3+)掺杂钠铝碲酸盐陶瓷上转换荧光分析

采用高温固相熔融法制备Tm3+/Yb3+、Ho3+/Yb3+和Tm3+/Ho3+/Yb3+掺杂钠铝碲酸盐陶瓷。用X射线衍射分析钠铝碲酸盐陶瓷的结构,结合974nm激光激发的上转换荧光,探讨上转换荧光强度与激发功率的关系。根据计算Tm3+/Ho3+/Yb3+掺杂样品上转换荧光色坐标,研究荧光色坐标与激发功率的关系。结果表明:钠铝碲酸盐陶瓷整体上呈无序结构,但存在少量α-Al2O3。由于Tm3+的上转换蓝光发射属三光子过程,Tm3+/Ho3+/Yb3+掺杂体系中,蓝光发光强度随激发功率增加而迅速增长的趋势比绿光和红光的更为明显。随着激发功率的增大,色坐标在1931CIE色品图中沿左下方朝蓝绿区方向移动,实现了上转换荧光的色彩变换。     

纳米氧化铁红颜料的室温固相合成

以FeSO4.7H2O和NH4HCO3为原料,在少量表面活性剂聚乙二醇(PEG)-400的存在下,先在室温下充分混合研磨进行固相反应,然后用水洗去反应混合物中的可溶性无机盐并烘干,即得氧化铁红的前驱体,前驱体再经热解即得氧化铁红产品。采用TG/DTA、IR、XRD和SEM对前驱体及其热解产品进行了表征。结果表明,前驱体的热解是经一步完成的,烘干后的前驱体碳酸亚铁已基本上分解成了氧化物;在550℃下热解前驱体2 h,得到了纯晶相的三方Fe2O3,其粒度约为43 nm。     

(2R,3S)-3-羟基-天冬氨酸盐酸盐的合成

介绍了羟基天冬氨酸的合成,以D-酒石酸二乙酯为原料,与氯化亚砜反应成亚磺酸类化合物,再与叠氮化钠发生开环反应后,催化加氢还原后得到羟基天冬氨酸二乙酯,经皂化反应后得到目标产物,4步反应的总收率为42%。     

3-甲基-2-硝基苯酚的合成工艺改进

以间甲基苯酚为原料,通过磺化、硝化、水解反应,合成3-甲基-2-硝基苯酚。考察了反应物料配比、反应时间、反应温度对收率的影响。收率为98%。目标化合物的结构经1H NMR确证。改进后的工艺降低了合成成本,简单可行,适合工业化生产。     

Formation of Core-Shell Structure in the BaTiO3-SrTiO3 System

When a 1-mol%-Fe₂O₃-added 0.67BaTiO₃-0.33SrTiO₃ (mole ratio) powder compact was sintered at 1380°C, a core-shell structure was developed. The core phase formed via solid-state interdiffusion of barium and strontium ions between BaTiO₃ and SrTiO₃ particles. In contrast, the shell phase formed via a solution-precipitation process in the presence of an Fe₂O₃-containing liquid phase. Energy-dispersive X-ray analysis showed that the core was a strontium-rich paraelectric phase and the shell was a barium-rich ferroelectric phase at room temperature. The core-shell structure developed in the BaTiO₃-SrTiO₃ system suggests the possibility of obtaining a variety of phase distributions with different Curie temperatures.