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1.
《Ceramics International》2022,48(1):10-21
Pc-WLEDs are considered to play a spectacular role in future generation light sources in view of their outstanding energy efficiency. In this regard, Eu3+ activated BaY2ZnO5 phosphor was prepared and investigated by XRD, PL and SEM analyses. Rietveld refinement analysis was carried out to confirm the structure of the synthesized phosphor. The prepared phosphor shows an intense red emission around 627 nm under excitation by near UV light. The 5D0-7F2 transition intensity of the prepared phosphor is three times higher compared to the commercial (Y,Gd)BO3:Eu3+ red phosphor. The CIE colour coordinates of BaY2ZnO5:Eu3+ (9mol%) phosphor corresponds to be (0.6169, 0.3742) and it has a high 97.9 % colour purity. The obtained results reveal the utility of BaY2ZnO5:Eu3+ phosphor as an efficient red component in WLEDs, anti-counterfeiting and fingerprint detection applications. 相似文献
2.
《International Journal of Hydrogen Energy》2022,47(69):29925-29944
Lithium iron phosphate battery (LIPB) is the key equipment of battery energy storage system (BESS), which plays a major role in promoting the economic and stable operation of microgrid. Based on the advancement of LIPB technology and efficient consumption of renewable energy, two power supply planning strategies and the china certified emission reduction (CCER) model are proposed respectively. Based on it, the multi-objective planning optimization model with economic benefits, environmental benefits and power supply stability as the objective function is established for the first time, and the Newton Weighted Sum Frisch method (NWSFA) solution model is adopted. In the planning process, rain flow counting method is used to research the life of BESS, which improves the accuracy of energy storage annual cost calculation. A park in northern China is taken as a case study to demonstrate the application of this model. The simulation results show that the annual economic operating cost of BESS is decreased by 18.81%, the energy supply reliability is increased by 0.15%, and the optimal electricity price adjustment ratio of the system is 15%. 相似文献
3.
《International Journal of Hydrogen Energy》2022,47(19):10736-10746
This study demonstrates the successful development of hybrid mesoporous siliceous phosphotungstic acid (mPTA-Si) and sulfonated poly ether ether ketone (SPEEK) as a proton exchange membrane with a high performance in hydrogen proton exchange membrane fuel cells (PEMFC). SPEEK acts as a polymeric membrane matrix and mPTA-Si acts as the mechanical reinforcer and proton conducting enhancer. Interestingly, incorporating mPTA-Si did not affect the morphological aspect of SPEEK as dense membrane upon loading the amount of mPTA-Si up to 2.5 wt%. The water uptake reduced to 14% from 21.5% when mPTA-Si content increases from 0.5 to 2.5 wt% respectively. Meanwhile, the proton conductivity increased to 0.01 Scm?1 with 1.0 wt% mPTA-Si and maximum power density of 180.87 mWcm?2 which is 200% improvement as compared to pristine SPEEK membrane. The systematic study of hybrid SP-mPTA-Si membrane proved a substantial enhancement in the performance together with further improvement on physicochemical properties of parent SPEEK membrane desirable for the PEMFC application. 相似文献
4.
在国内,火花放电原子发射光谱分析广泛使用类型标准化进行方法校正。在国外,标准和文献中鲜见使用此方法的相关论述。类型标准化主要采用平移校正和转动校正两种方式,哪种方式更加合理也鲜见报道。国外设备类型标准化的默认设置优先采用转动校正方式,相关国内标准对最优校正方式的规定尚不明确,此默认设置的合理性有待探讨。实验选用低合金钢20CrNi2Mo、R407标准样品和不锈钢317L、0Cr18Ni9标准样品,引用国内相关标准,以正确度临界差为评判依据,模拟类型标准化样品和待测样品“十分接近”和“接近”两种情况下平移校正和转动校正的数据正确度。经数据统计分析,平移校正分析结果均满足要求,转动校正结果在“接近”情况下部分元素不满足要求。结合相关国家标准中元素含量范围和精密度数据进行分析,通过计算允许最大偏倚量并制作曲线图方式展开分析,得出如下结论:在满足文中类型标准化控制要点前提下,分析设置更适合于采用平移校正方式。 相似文献
5.
《Ceramics International》2022,48(5):6372-6384
Sm2O3-HfO2 series ceramics were synthesized at high temperature using the solid-state reaction. The phase stability, thermo-physical and infrared emission properties of Sm2Hf2O7 (SHO) and Sm2Hf2O7-44.83 wt%HfO2 (25S/H) composite ceramics were comparatively investigated. Furthermore, their calcium magnesium aluminosilicate (CMAS) corrosion was conducted at 1250°C for different times. The results reveal that both SHO and 25S/H ceramics have excellent phase stability at 1600°C as well as excellent sintering resistance. SHO still exhibits slightly lower thermal conductivity and lower hardness and Young's modulus, higher thermal expansion coefficient (CTE) and fracture toughness as well as higher infrared emittance (0.899 at 800°C) than 25S/H composite with the excessive HfO2 inside. Both SHO and 25S/H ceramics react with CMAS to form a relatively compact reaction layer, which can effectively prevent the penetration of CMAS. These results preliminarily indicate that SHO ceramic can be proposed as an alternative material of the traditional YSZ for high-temperature thermal protective applications thanks to its compatible performance of low thermal conductivity and high infrared radiation, etc. 相似文献
6.
《中国有色金属学会会刊》2021,31(8):2468-2478
An acoustic emission (AE) experiment was carried out to explore the AE location accuracy influenced by temperature. A hollow hemispherical specimen was used to simulate common underground structures. In the process of heating with the flame, the pulse signal of constant frequency was stimulated as an AE source. Then AE signals received by each sensor were collected and used for comparing localization accuracy at different temperatures. Results show that location errors of AE keep the same phenomenon in the early and middle heating stages. In the later stage of heating, location errors of AE increase sharply due to the appearance of cracks. This provides some beneficial suggestions on decreasing location errors of structural cracks caused by temperature and improves the ability of underground structure disaster prevention and control. 相似文献
7.
《Ceramics International》2021,47(22):31457-31469
The present work investigated the effects of thermal cycles in air on the tensile properties of a two-dimensional carbon fibre reinforced silicon carbide composite (2D C/SiC) prepared by chemical vapour infiltration at different heating rates. The composite was exposed to different cycles of thermal shock between 20 °C and 1300 °C in air. The damage mechanisms were investigated by AE online monitoring and fractured morphology offline analysis. The tensile strength of 2D-C/SiC decreases with increasing thermal cycles. However, the modulus only decrease within 40 cycles. Due to oxidation, with the decrease in heating rate, the residual properties of the material decrease more obviously. Meanwhile, the results of AE online monitoring and fracture analysis show that the matrix damage is more serious at higher heating rate and that more delamination occours in tensile fractures. The above results indicate that for the thermal shock of 2D C/SiC composites in air, oxidative damage plays a key role in the residual properties. 相似文献
8.
Jiangkun Cao Aaron Reupert Yicong Ding Lothar Wondraczek 《Journal of the American Ceramic Society》2022,105(4):2616-2624
Tuning the optical properties of active species embedded within a glass matrix by modifying the ligand environment is of interest for luminescence-based technologies, for example, in optical sensing, data transmission, or spectral conversion. Here, we discuss a facile synthesis procedure for a glass-crystal composite material comprising of bismuth (Bi)-doped zirconia within an aluminoborate glass phase. The approach offers tunable and broad photoemission characteristics in the visible spectral region from 400 to 750 nm. Incorporation of Bi ions into the crystal phase enhances the photoemission intensity by two orders of magnitude, with an external quantum efficiency of about 29%. At higher ZrO2 dopant concentration, we observe a red-shift of both the excitation and the emission bands to match commodity ultra-violet light emitting diodes as excitation sources. Encapsulation within the aluminoborate glass phase provides advantageous thermal behavior, with the emission intensity remaining at >80 % of its initial value up to a temperature of 400 K. 相似文献
9.
《Ceramics International》2022,48(15):21663-21670
In this study, two series of GaxSb40-xS60 (x = 4, 6, 8, 10 mol%) and GaySb36S64-y (y = 3, 5, 6 mol%) glasses were prepared and the relationship between their compositional and acousto-optic (AO) properties was investigated systematically for the first time. In the GaySb36S64-y system, the AO figure of merit (M2) increased as the Ga increased, and the maximum M2 of the Ga6Sb36S58 glass was 455.78 × 10?18 s3/g, which is ~301 times greater than that of fused silica and ~2.5 times greater than that of As2S3 chalcogenide (ChG) glass at 1550 nm. However, its thermo-optic coefficients (dn/dT) varied greatly (32.1 × 10?6 °C?1–57.2 × 10?6 °C?1), and acoustic attenuations (α) at 10 MHz were high, from 5.446 dB/cm to 7.274 dB/cm. In the GaxSb40-xS60 glass system, the M2 value and α at different ultrasonic frequencies gradually decreased with the improvement of Ga. Compared with the GaySb36S64-y system, the GaxSb40-xS60 glass system had lower α (at 10 MHz) and dn/dT, which are 5.001 dB/cm–5.563 dB/cm and 17.3 × 10?6 °C?1–55.6 × 10?6 °C?1, respectively. These results provide a significant reference for the further development of novel ChG glasses and help expand their application fields. 相似文献
10.
《Ceramics International》2022,48(2):1494-1511
The application of insulation materials in buildings and energy storage facilities is gaining global attention to reduce energy consumption, heat loss, and CO2 emissions. Given the high insulation performance, glass foam is gaining popularity replacing combustible, high energy-consuming, and costly conventional insulation materials. The industrial process of glass foam manufacturing is an energy-consuming and non-ecofriendly process which requires the annealing of glass around its melting temperature. Therefore, researchers have developed powder sintering and gel casting methods to sinter glass foam mix at a temperature slightly above its glass transition point. However, research findings on these two methods are scattered because of the different parameters being used by researchers. The properties and performances of glass foam depend on the processing parameters, especially on the materials design and sintering conditions. Therefore, this study aimed to provide a comprehensive review on the key parameters for material selection and sintering of glass foams and provide necessary guidelines for the best practice and a direction for future research. Moreover, this review covers the current strategies and challenges associated with the powder sintering and gel casting methods including their sustainability and environmental performance. 相似文献