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91.
92.
随着人才培养模式的推陈出新,学术交流作为文化交流的方式,促进教师队伍共同发展。本文分析了学术交流档案的内容、重要性,对学术交流档案管理提出了几点建议:建立并完善学术交流档案管理体制;加强培训档案管理专业知识;加强学术交流成果展示;将信息化建设引入到学术交流档案管理中。 相似文献
93.
Muhammad Khurram Tufail Niaz Ahmad Le Yang Lei Zhou Muhammad Adnan Naseer Renjie Chen Wen Yang 《中国化学工程学报》2021,39(11):16-36
The development of an inorganic electrochemical stable solid-state electrolyte is essentially responsible for future state-of-the-art all-solid-state lithium batteries (ASSLBs). Because of their advantages in safety, working temperature, high energy density, and packaging, ASSLBs can develop an ideal energy storage system for modern electric vehicles (EVs). A solid electrolyte (SE) model must have an economical synthesis approach, exhibit electrochemical and chemical stability, high ionic conductivity, and low interfacial resistance. Owing to its highest conductivity of 17 mS·cm-1, and deformability, the sulfide-based Li7P3S11 solid electrolyte is a promising contender for the high-performance bulk type of ASSLBs. Herein, we present a current glimpse of the progress of synthetic procedures, structural aspects, and ionic conductivity improvement strategies. Structural elucidation and mechanistic approaches have been extensively discussed by using various characterization techniques. The chemical stability of Li7P3S11 could be enhanced via oxide doping, and hard and soft acid/base (HSAB) concepts are also discussed. The issues to be undertaken for designing the ideal solid electrolytes, interfacial challenges, and high energy density have been discoursed. This review aims to provide a bird's eye view of the recent development of Li7P3S11-based solid-state electrolyte applications and explore the strategies for designing new solid electrolytes with a target-oriented approach to enhance the efficiency of high energy density all-solid-state lithium batteries. 相似文献
94.
Przemysław Gołębiewski Helena Węglarz Magdalena Nakielska Anna Wajler 《International Journal of Applied Ceramic Technology》2021,18(3):697-704
In this work, we investigated the effects of Ca2+ and Mg2+ ions and annealing temperature on the spectroscopic parameters of chromium-doped yttrium aluminum garnet ceramics (Cr:YAG). Samples were obtained with either a separate or a simultaneous addition of calcium and magnesium oxides. To achieve this, aqueous suspensions were prepared using Y2O3, Al2O3, Cr2O3, MgO, and CaO high-purity powders as raw materials. The obtained suspensions were freeze-granulated, pressed into pellets, debinded, and subjected to reactive sintering in vacuum at 1715°C for 6 h. Each material was annealed in air with temperatures between 1300 and 1700°C. Samples were also compared to Cr:YAG ceramics with the addition of silica as a sintering aid. All the materials obtained were then exposed to 445 nm excitation, and emission spectra in the visible and infrared wavelengths were recorded. The results showed that the emission spectra of Cr:YAG ceramics varied according to the annealing conditions: as-sintered samples exhibited strong emissions of around 680 nm and, after air annealing, of around 1400 nm. This phenomenon is attributed to the Cr3+→Cr4+ transition. Samples doped solely with MgO exhibited the highest emission intensity in the infrared region. Thus, Mg2+ ions provided the best conversion efficiency of chromium ions. 相似文献
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《中国稀土学报(英文版)》2022,40(6):942-951
To upgrade the electric properties of lead-free piezoceramics, (1–x)(Ba0.98Ca0.02Ti0.94Sn0.04Zr0.02)O3-xY2O3 (abbreviated as (1–x)BCTSZ-xY, x = 0 mol%, 0.02 mol%, 0.04 mol%, 0.06 mol%, 0.08 mol% and 0.1 mol%) ceramics were successfully synthesized by traditional solid-state sintering method. The phase structure and microstructure of ceramics were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and piezoresponse force microscopyeramics (PFM). The electric properties of ceramics were researched through piezoelectric, dielectric and ferroelectric test instruments. The results show that all samples have pure perovskite structure and favorable electric properties. The optimal electric properties which especially include superior ferroelectric properties are gained when Y2O3 content is 0.06 mol% (d33 = 419 pC/N, kp = 52%, Tc = 89.5 °C, εr = 26900, tanδ = 2.86%, Pr = 14.41 μC/cm2, Ec = 1.8 kV/cm). Moreover, the temperature-dependent dielectricity of samples shows apparent relaxor behavior under different frequencies. The Curie–Weiss law further proves that all samples are typical relaxor ferroelectrics, and the relaxor degree of samples decreases with increase of Y2O3 content. In conclusion, Y2O3 plays a significant role in enhancing electric properties of BCTSZ ceramics. 相似文献
97.
Effects of CeO2 doping on the structure and properties of PSN-PZN-PMS-PZT piezoelectric ceramics 总被引:1,自引:0,他引:1
SUN Qingchi LU Cuimin ZHOU Hua 《稀有金属(英文版)》2005,24(3):235-239
Quinary system piezoelectric ceramics PSN-PZN-PMS-PZT were prepared by using a two-step method. The effects of CeO2 doping on piezoelectric and dielectric properties of the system were investigated at morphotropic phase boundary (MPB). The results reveal that the relative dielectric constant ε33^T|ε0, the Curie temperature To, the piezoelectric constant d33, the mechanical quality factor Qm, and the electromechanical coupling coefficient Kp are changed with the increase of CeO2 content. On the other hand, the effects of CeO2 doping on the dielectric properties of PSN-PZN-PMS-PZT piezoelectric ceramics at high electric field are consistent with the change at weak electric field. The values of dielectric constant and dielectric loss are enhanced with the increasing of electric field. 相似文献
98.
99.
100.
(反应)模晶生长法制备NBT-6BT织构陶瓷的研究 总被引:1,自引:0,他引:1
以熔盐法合成的片状SrTiO3,Bi4Ti3O12为种晶,分别采用模晶生长法(TGG)和反应模晶生长发(RTGG)制备了具有〈001〉取向的0.94(Na1/2Bi1/2)TiO3-0.06BaTiO3(NBT-6BT)织构陶瓷。研究了不同种晶选择、流延和热处理工艺参数对陶瓷织构化程度、显微结构和压电性能的影响。结果表明,RTGG制备的织构陶瓷比TGG的在结构和性能等方面都具有优势,且用该方法以Bi4Ti3O12为种晶,制备出了高密度(f≥96%)、高织构度(F≈95%)、高性能(d33≈241pC/N)的NBT-6BT无铅压电陶瓷。 相似文献