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181.
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Huixu Xie Jianyun Wang Chuansong Li Zhipeng Gu Qianming Chen Longjiang Li 《Ceramics International》2013,39(8):8945-8954
The critical success factors for bone tissue engineering in clinical applications are scaffolds. Ion doping is one of the most important methods to modify the properties of bioceramics for better angiogenesis abilities, biomechanical properties, and biocompatibility. This paper presents a novel ion doping method applied in calcium polyphosphate (CPP)-based bioceramic scaffolds substituted by strontium ions to form (SCPP) scaffolds for bone tissue regeneration. The microstructure and crystallization of the scaffolds were detected by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Degradation tests were assessed to evaluate the mechanical and chemical stabilities of SCPP in vitro. The cell biocompatibility was measured with respect to the cytotoxicity of the extractions of scaffolds. Bone implantation was performed to evaluate the biodegradability and osteoconductivity of the scaffolds, and the bone formation examined by using X-ray radiography. The results indicated that the obtained SCPP scaffolds had a single CPP phase. The SCPP scaffolds yielded a better degradation property than the pure CPP scaffold. The MTT assay and in vivo results reveal that the SCPP scaffolds exhibited a better cell biocompatibility and tissue biocompatibility than CPP and hydroxyapatite (HA) scaffolds. The in vivo immunohistochemistry staining for VEGF also showed that SCPP had a potential to promote the formation of angiogenesis and the regeneration of bone. SCPP scaffold could serve as a potential biomaterial with stimulating angiogenesis in bone tissue engineering and bone repair. 相似文献
183.
化学强化是一种玻璃机械强度增强方法,适用于异型、超薄、高碱、高膨胀玻璃增强,因新型超薄显示产品的屏幕保护玻璃发展需要,化学强化技术重新在碱铝硅酸盐玻璃品种掀起研究热潮。本文对化学强化本质及铝硅酸盐玻璃在屏幕保护玻璃应用进行了回顾,基于玻璃化学强化的高CS、DOL和低CT诉求,归纳总结了关键影响因素,第1,碱铝硅酸盐玻璃的成分及结构是基础,氧化铝有利玻璃网络孔隙增大创造交换通道,氧化钠或氧化锂是离子交换关键物质;第2,对于玻璃组成和结构设计,要求玻璃网络键合度R=O/Si或O/(Si+Al)满足2.15~2.40,碱金属氧化物质量分数大于13%且膨胀系数大于6×10^-6/℃;第3,在化学强化工艺方面,化学强化温度决定离子扩散系数,化学强化时间决定DOL,一步法仅能获得相对较大的CS,而DOL不很理想,只有两种离子参与交换的二步法才有利于CS和DOL同步提高。 相似文献
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《Ceramics International》2023,49(12):19879-19884
As an important renewable energy, hydrogen energy becomes an important part of the future energy system. Proton ceramic electrolysis cell (PCEC) enables the efficient, clean, large-scale preparation of hydrogen, which is a new type of energy conversion device, attracting the attention of many researchers. Sr2Fe1.4Zn0.1Mo0.5O6-δ (SFZM) anode materials were developed to investigate the effect of B-site doping of Zn on the electrochemical properties of the Sr2Fe1.5Mo0.5O6-δ (SFM) materials. The results reveal that the doping of Zn increases the concentration of oxygen vacancies and improves the electrocatalytic activity, which in turn improves the performance of the material. A current density of 408 mA cm−2 has been achieved at 1.3 V when the SFZM-based single cell was operated in an electrolysis mode (50% H2O in air) at 600 °C, higher than SFM-based single cells (286 mA cm−2 at 1.3 V). In addition, the SFZM-based single cell exhibited good durability in a stability test at an electrolysis current density of 408 mA cm−2. This work confirms that SFZM is a promising material for proton ceramic electrolysis cell anode. 相似文献
186.
This study investigated the distance effect on water reduction by the wicking geotextile in a base course experimentally using three sets of soil column tests. In each set of tests, two soil columns were constructed by compacting well-graded aggregate over a non-wicking woven geotextile and a wicking geotextile. A portion of the geotextile specimen was extended outside of the soil column for evaporation. The changes of the water contents in the soil column were monitored by volumetric water content sensors installed at various depths. The experimental results indicate the capillary drainage by the wicking geotextile effectively reduced water content within the soil column up to a distance from the wicking geotextile (i.e., approximately 200 mm for this specific aggregate with 10% fines). The test results also show that the wicking geotextile could reduce more water content of the aggregate below its optimum water content at a faster rate than the non-wicking geotextile. 相似文献
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预应力锚索框架梁在山地边坡加固中的应用 总被引:3,自引:0,他引:3
预应力锚索框架梁支护结构采用对预应力锚索施加预应力,将潜在滑动岩土体与稳定岩体连接为一体.根据山地住宅建设别墅群的特点,介绍预应力锚索框架梁支护结构在山地住宅边坡加固中的作用机理.并结合工程实例,通过对支护形式进行选择,以及设计计算分析,使得支护安全系数满足建筑规范的要求.同时取得了良好的支护效果,保证了工程的安全性. 相似文献
190.
非对称用户数字线路的性能受多个因素影响,故障复杂.本文在简要介绍宽带测试方案的基础上,介绍了一种基于统计决策法的方案.用这样的方案改进原有的测试方案,可以使系统具有更优的精度. 相似文献