检索结果-南通市图书馆

Synthesis of piezoelectric nanocrystalline PZT powder by stearic acid gel method

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2005年第2期24卷 142-145页

作者： HAOJunjie WANGXiaohui GUIZhilun LILongtu StateKeyLaboratoryforNewCeramicsandFineProcessing DepartmentofMaterialsScienceandEngineeringTsinghuaUniversityBeijing100084China materialsScienceandEngineeringSchool UniversityofScienceandTechnologyBeijingBeijing100083China

PZT nanocrystalline powder was prepared by a stearic acid gel method. Thecrystallization process from the precursor was monitored by infrared spectroscopy, differentialthermal analysis, and thermogravimetric analysis. The nano-sized PZT powder was characterized byX-ray diffraction and transmission electron microscopy. It shows that pure single-phase PZT powdercould be obtained at 450 deg C for 1 h, and the particle size is about 20 nm. With an increase inthe calcination temperature, the PZT crystallite size increased.

关键词： inorganic nonmetal material powder stearic acid method piezoelectric PZT

Preparation and microwave hexaferrites by a sol-gel process

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2004年第1期23卷 27-31页

作者： ZHANGHaijun JIAXiaolin YAOXi ZHANGLiangying HighTemperatureCeramicsInstitute ZhengzhouUniversityHenan450052.China FunctionalmaterialsResearchLaboratory TongjiUniversityShanghai200092China

s Ba_4Zn_zCo_(2-z)Fe_(36)O_(60) hexaferrites with Z = 2.0, 1.5, 1.0, 0.5, and0.0 were prepared by a citrate Sol-gel process. The complex dielectric constant and complexpermeability of hexaferrite-paraffin wax composites were measured in the range from 0.1 to 6.0 *** results showed that both the complex dielectric constant and the dielectric loss exhibitedno significant change as the measuring frequency increasing except for the sample with Z = 0.0. Thereal part of permeability decreased with increasing frequency for all samples in the whole measuringfrequency range, and the natural resonance phenomena were observed in all μ″ spectrum but Co_*** results also indicate that the content of zinc closely affects the microwave properties ofBa_4Zn_zCo_(2-z)Fe_(36)O_(60) ferrites, and the greater the zinc content, the lower the naturalresonance frequency is.

关键词： inorganic nonmetal material sol-gel Ba_4Zn_zCo_(2-z)Fe_(36)O_(60) hexaferrite microwave property

Microstructures and Adhesive Strength of Three Kinds of Ceramic Coatings

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2007年第S1期25卷 489-492页

作者：邱关明崔彤李喜坤丘泰姜茂发刘立新 Nanjing University of Technology Shenyang University of Science and Technology School of material and Metallurgy Northeast University Schhool of materials and Chemical Engineering Changchun University of Science and Technology

In gas turbine engine, the study of ceramic thermal resistance coating has always been paid more attention because it can effectively reduce metal interface temperatures, improve corrosion and/or oxidation resistance and extend life. The microstructures, SEM microfractographs and adhesive strength of three kinds of zirconia plasma-sprayed ceramic coating were investigated. The results indicated that nanostructured zirconia coating have higher adhesive strength and better micro-cracking resistance properties compared with magnesia or yttria stabilized zirconia coating because its less quantities laminar internal structures and closed packed structures with less quantities and uniform distribution cavities. The sprayed power is also an important factor affecting adhesive strength of nanostructured zirconia coating.

关键词： inorganic nonmetal material thermal barrier coatings (TBCs) plasma-sprayed nanostructured zirconia adhesive strength

Synthesis of CaO-SiO_2-B_2O_3∶Sm_2O_3 Glasses and Luminescent Properties of Sm^(3+)

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2005年第4期23卷 428-428页

作者： Shi Pengtu Shu Wangen Yu Jian Lǖ Xingdong College of Chemistry and Chemical Engineering Central South University Changsha 410083 China Hunan Province Product Commodity Quality Supervision Testing Institute Changsha 410007 China

CaO-SiO2-B2O3 ：Sm2O3 glasses were synthesized in air atmosphere with conventional high temperature process. The optimal temperature of synthesis, the absorption spectrum and the luminescent properties of the glasses were studied. The fluorescence spectrum of Sm^3＋ was observed in CaO-SiO2-B2O3 ： Sm2O3 glasses. The fluorescence spectrum of the sample has three major emission bands peaking at 568, 605 and 650 nm respectively. The strongest emission band peak at 605 nm. It is concluded that the emissions were caused by the f-f transition of the 4f electrons of Sm^3＋. The emission bands peaking at 568, 604 and 650 nm correspond to the ^4G5/2→^6H5/2 transition, ^4G5/2→^6H7/2 transition and ^4G5/2→^6H9/2 trasition respectively. The luminescent properties of CaO-SiO2-B2O3 glasses indicate that the glass can convert the ultraviolet in the sunlight into red light, thus increasing the intensity of red light. The luminescent properties of these glasses may be used to make kinds of light-conversion glass for agriculture.

关键词： inorganic nonmetal material luminescent properties rare earth activated glass light-conversion rare earths