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991.
Yun-Han Su Cheng-Tang Pan Yu-Sheng Tseng Ji Zhang Wen-Fan Chen 《Ceramics International》2021,47(14):19414-19423
Cerium (Ce)-substituted diopsides (CaMgSi2O6) with enhanced mechanical strength and bioactivity were fabricated by precipitation method, followed by annealing at 1000 °C for 4 h. The mineralogical, morphological, in vitro biomineralization, degradation, and mechanical properties were investigated in order to assess the factors and mechanisms affecting the resultant properties. The X-ray diffractometer results showed that the onset of substitutional solid solubility in 0.25 mol Ce would result in new phase formation (cerium dioxide [CeO2], and magnesium silicate [MgSiO3]) further causing lattice instability. With increasing Ce dopant levels to 1.00 mol, the initial CaMgSi2O6 phase was completely replaced by new phases. The field-emission scanning electron microscopy results indicated that the 0.25 mol Ce had the best biomineralization performance in vitro, while less hydroxyapatite precipitates were found with further increasing Ce dopant levels, suggesting the new phases led to the hindrance of precipitates. The weight loss values indicated that the high dissolution rate of ions in the matrix was observed in the pure sample, while the high readsorption rate of ions in the simulated body fluid (SBF) occurred with increasing Ce dopant levels. The pH value and the inductively coupled plasma-mass spectrometer results suggested that the release of Ca and Mg ions controlled the pH value. The mechanical strength of matrices before SBF immersion was related to the phase transformation, the elastic modulus of CeO2 and CaMgSi2O6, and the release of Mg ions, while the mechanical strength of matrices after SBF immersion was dominated by the structure of matrices. 相似文献
992.
Wai Shin Ho Cheng Seong Khor Haslenda Hashim Sandro Macchietto Jiří Jaromír Klemeš 《Clean Technologies and Environmental Policy》2014,16(5):957-970
This work proposes a novel approach called stand-alone hybrid system power pinch analysis (SAHPPA), which is particularly applicable for the design of off-grid distributed energy generation systems. The enhanced graphical tool employs new ways of utilising the recently introduced demand composite curve and supply composite curve while honouring and adapting fundamental energy systems engineering concepts. The SAHPPA method is capable of optimising the capacity of both the power generators and energy storage for biomass (i.e. non-intermittent) and solar photovoltaic (i.e. intermittent) energy technologies, which is a contribution to the emerging area of power pinch analysis. In addition, the procedure considers all possible efficiency losses in the overall system encompassing the charging–discharging and current inversion processes. 相似文献
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中国居民膳食以谷物为主食,谷物中铁吸收率低是造成营养性贫血的主要原因,适当的加工方式可缓解谷物中植酸、多酚等物质对铁生物利用率(Fe bioavailability,FeBV)的影响。为考察酵母发酵对面粉FeBV的影响,采用体外消化/Caco-2细胞模型。结果表明,面团在发酵后pH值呈下降趋势,酸度呈上升趋势;多酚、植酸含量降低,植酸酶活性升高,以上各指标在发酵前后差异均具有统计学意义(P0.05)。发酵后面粉样品的FeBV增加约5%~38%,大多数面粉FeBV发酵前后比较,差异具有统计学意义(P0.05)。结论:发酵可降低面粉的pH值,增加酸度,有利于面粉多酚和植酸的降解以及植酸酶活力的升高,可有效提高面粉FeBV。 相似文献
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铁路南昌西站屋面钢桁架存在着单体面积大、结构复杂、工期紧等诸多特点,通过对屋面钢桁架结构型式的研究,并结合地铁、出租车通道、站房主体预应力混凝土框架结构的特点,创造性地提出了主体预留、充分利用出租车通道和地铁隧道箱涵本身刚度,使地面免加固即可行走大吨位履带吊,以南北分向转场吊装屋面钢结构的施工新方法,不仅极大地降低了施工成本,并且安全快速地确保了屋面钢桁架的吊装进度和质量. 相似文献
1000.
Yinxiang Wang Muhammad Zaki Memon Majid Ali Seelro Weng Fu Yuan Gao Yingchao Dong Guozhao Ji 《International Journal of Hydrogen Energy》2021,46(45):23358-23379
Sorption-enhanced-steam-reforming (SESR) is a thermochemical conversion technology that produces a high-purity hydrogen stream by utilizing in-situ removal of CO2 with a sorbent. In this paper, the advantages and disadvantages of CaO based sorbents, alkali-metal based sorbents (Na2ZrO3, Li2ZrO3 and Li4SiO4), hydrotalcite based sorbents, bifunctional materials and sorbents prepared from wastes are briefly discussed, and the techniques to improve the sorption properties of these CO2 sorbents are summarized. In the process of hydrogen production by sorption-enhanced-steam-reforming, the selection of suitable high-temperature CO2 sorbent is the key to produce high purity hydrogen. Furthermore, the hydrogen-production performance of the above-mentioned sorbents in the SESR process is investigated and summarized. Finally, a future perspective and some suggestions regarding these five types of sorbents are put forward. 相似文献