共查询到19条相似文献,搜索用时 140 毫秒
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硼硅酸盐生物活性玻璃具有良好的生物活性和骨传导性, 但大多数生物活性玻璃表现出非线性降解和矿化行为, 矿化性能会随着时间而减缓。电场作为一种外场辅助调节的方法, 能够干预玻璃的离子交换和扩散。本研究利用直流电场干预硼硅酸盐生物活性玻璃的体外矿化, 加快降解较慢阶段中硼硅酸盐生物玻璃的生物活性。将熔融法制备的成分为18SiO2-6Na2O-8K2O-8MgO-22CaO-2P2O5-36B2O3的硼硅酸盐生物活性玻璃浸泡在SBF生理模拟液中, 施加0~90 mA的电流, 研究直流电场对硼硅酸盐生物玻璃降解及体外矿化性能的影响。研究结果表明, 施加电场不仅可以提高硼硅酸盐生物活性玻璃的降解率和离子释放量, 而且有利于玻璃网络水解和表面羟基化, 加速羟基磷灰石的生成。其中失重率比对照组提高了3%~5%, 硼和钙的离子释放量分别较对照组提高了2.3~2.9倍和1.9~2.3倍。对硼硅酸盐生物活性玻璃表面结构分析得出, 暴露在电场下的样品表面生成了磷灰石层。应用直流电场可以提高生物活性玻璃的降解及体外矿化性能, 为提升骨修复效果提供了一种新思路。 相似文献
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《无机材料学报》2021,(9)
硼硅酸盐生物活性玻璃具有良好的生物活性和骨传导性,但大多数生物活性玻璃表现出非线性降解和矿化行为,矿化性能会随着时间而减缓。电场作为一种外场辅助调节的方法,能够干预玻璃的离子交换和扩散。本研究利用直流电场干预硼硅酸盐生物活性玻璃的体外矿化,加快降解较慢阶段中硼硅酸盐生物玻璃的生物活性。将熔融法制备的成分为18SiO_2-6Na_2O-8K_2O-8MgO-22CaO-2P_2O_5-36B_2O_3的硼硅酸盐生物活性玻璃浸泡在SBF生理模拟液中,施加0~90 m A的电流,研究直流电场对硼硅酸盐生物玻璃降解及体外矿化性能的影响。研究结果表明,施加电场不仅可以提高硼硅酸盐生物活性玻璃的降解率和离子释放量,而且有利于玻璃网络水解和表面羟基化,加速羟基磷灰石的生成。其中失重率比对照组提高了3%~5%,硼和钙的离子释放量分别较对照组提高了2.3~2.9倍和1.9~2.3倍。对硼硅酸盐生物活性玻璃表面结构分析得出,暴露在电场下的样品表面生成了磷灰石层。应用直流电场可以提高生物活性玻璃的降解及体外矿化性能,为提升骨修复效果提供了一种新思路。 相似文献
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系统研究了SiO2与B2O3之比、高熔点添加剂种类(包括MoSi2,Y2O3,SiC)及含量对硼硅酸盐(SAB)玻璃涂层高温稳定性、高温流动性的影响规律和最佳工艺参数组合,采用涂刷法在带有疏松结构的SiC内涂层炭/炭(C/C)复合材料表面制备了高温稳定性和流动性良好的硼硅酸盐玻璃外涂层,并测试了带有不同SiC/硼硅酸盐玻璃复合涂层C/C复合材料试样在1500℃静态空气中的抗氧化性能.结果表明:采用SiO2,B2O3摩尔比为4∶1时所得硼硅酸盐玻璃具有相对较高的高温流动性和高温稳定性;与添加Y2O3,SiC相比,在上述硼硅酸盐玻璃中添加MoSi2可以较大幅度提高所得玻璃涂层对C/C基体的氧化保护性能,并且当硼硅酸盐玻璃外涂层中硼硅酸盐与MoSi2的质量比为4∶1时,所得硼硅酸盐玻璃外涂层对SiC-C/C表现出较好的氧化保护能力,氧化17h后涂层C/C试样的失重仅为4.31%. 相似文献
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恒定无碱铝硼硅酸盐玻璃中碱土金属氧化物的质量百分比不变,研究了SrO和CaO的相互替代对玻璃的热膨胀系数、应变点温度、玻璃转变温度、退火点温度、膨胀软化点温度等低温特征粘度参考点的影响。结果表明:玻璃的热膨胀系数随着n(SrO)/n(CaO)比值的增大而逐渐减小,低温特征粘度参考点在n(RO)/n(Al2O3)=0.96时达到极大值。 相似文献
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目的 药品包装材料与药物相容性实验是评价药品包装材料安全性能与药品质量的重要研究项目,中性硼硅玻璃具有膨胀系数小、耐极冷极热性强、不易炸裂、化学稳定性好等特点,已成为注射剂包装的首选材质.探索中性硼硅玻璃与药物相容性的研究进展与发展趋势,为中性硼硅玻璃用于药品包装材料提供参考.方法 分别从玻璃成分中金属离子向药液中的迁移量、有害物质的浸出量、不同温度与酸碱条件下玻璃的脱片、玻璃对药物的吸附以及药物对玻璃表面的侵蚀程度等方面综述中性硼硅玻璃与药物相容性的研究进展,考察中性硼硅玻璃对于药品质量的影响.结论 中性硼硅玻璃与药物的相容性评价方法逐渐完善,为中性硼硅玻璃作为药用包装材料的研究提供参考. 相似文献
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Shen-Tsu Wang 《国际生产研究杂志》2016,54(16):4882-4893
The touch panel cover glass is one of the important parts and components that determine touch panel quality. The quality requirement of touch panel cover glass emphasises the stability of glass thickness. As this factor directly influences the induction effect and touch of the touch panel, the parameter conditions for the cover glass polishing process have significant impact. This study integrated grey sequencing with the Genetic algorithm–Immune algorithm to optimise the parameter design for the touch panel cover glass polishing process. The experimental measurement value was the thickness value of the processed glass, and the uniformity of glass thickness after processing was discussed. The optimum processing combination influencing the process conditions is as follows: the ambient temperature is 22 (°C), the processing pressure is 0.04 (Mpa), the processing time is 30 (min), the machine speed is 70 (rpm), the polishing solution concentration is 1.4 (g/cm3), the central particle size of polishing powder is 1.4 (um) and the process capability Cpk is 1.75, which is better than the process capability of Cpk 1.41 of the response surface methodology and the process capability of Cpk 1.37 of the Taguchi experimental design. 相似文献
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Sumit Kumar 《Materials and Manufacturing Processes》2018,33(11):1188-1196
BK7 is a high-quality crown glass which is used where additional benefits such as temperature sensitive applications of fused silica glass are not required. Due to very low inclusion content with extremely low bubbles, BK7 glass can find its application in lens manufacturing. The present work focuses on nanofinishing of the BK7 glass specimen for ratifying its utility in practical application. A programmable logic controlled 3-axis motions are fed to the magnetorheological (MR) rotating tool for finishing the glass specimen. MR polishing fluid used for nanofinishing consists of deionized water, magnetic iron particles, and cerium oxide powder. Under the influence of magnetic field, the stiffened MR polishing fluid is assisted in reducing the surface roughness of glass up to nanolevel range. Optical properties such as transmittance, absorbance, and reflectance of finished BK7 glass are analyzed and found suitable for lens manufacturing. Results of higher surface quality with excellent finishing are obtained by the present MR finishing process. After 90?min of finishing, the surface roughness values Ra and Rq are reduced to 17 and 27?nm from the initial values of 41 and 57?nm, respectively. To study the surface morphology, scanning electron microscopy is performed on BK7 glass. 相似文献
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在浮法玻璃生产中硫酸钠通常与还原剂一起作为澄清剂使用。研究硫酸盐在玻璃生产过程中的反应机理对探索玻璃形成与澄清机理、提高浮法玻璃质量具有重要意义。本文综述了近年来对硫酸盐在玻璃熔窑和锡槽中的研究进展。首先论述了硫酸钠在玻璃熔化、澄清过程中的物理化学变化和澄清机理,包括硫酸盐与碳的反应和气泡形成长大和收缩过程;其次讨论了玻璃熔体进入锡槽后,由于气氛的改变及残余硫酸钠价态的变化,以及对玻璃上下表面和锡液的影响。 相似文献
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利用硼硅酸盐玻璃的分相和酸侵蚀制备了孔径可控的多孔玻璃粉,采用SEM、BET等测试手段对玻璃的表面形貌和孔径分布进行了表征。并以Na2O-Al2O3-B2O3体系低熔点玻璃作为粘接剂将多孔玻璃粉烧结在普通玻璃板上,研制出一种表面孔径约50nm且均匀分布的多孔玻璃基板,并分析了烧结温度、烧结时间、颗粒大小等对粘接的影响。 相似文献
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采用人工加速风化的方法研究了镀有SiO2薄膜的浮法玻璃的风化性能,并与相同风化条件下的浮法玻璃原片的表面状态进行了比对,从风化机理上进行了分析。红外反射光谱和扫描电镜分析结果表明,镀有SiO2薄膜的浮法玻璃和未镀膜玻璃随着风化温度和风化时间的增加,均呈现风化现象逐渐加重的现象。但前者风化程度明显低于后者,尤其当风化条件(70℃,75%RH,风化15d)恶劣时,镀膜玻璃表面只出现了小块斑点和红外光谱的略微变化;而未镀膜玻璃表面则出现大面积的侵蚀斑块,在红外谱图上不仅≡Si—O—Si≡特征峰发生位移,而且出现了C?O的特征峰。说明SiO2膜层能够很好地阻挡玻璃表面Na+与空气中H+、H3O+的交换,有效地抑制玻璃表面风化的发生。 相似文献
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Raj Kumar Pal Harry Garg RamaGopal V. Sarepaka Vinod Karar 《Materials and Manufacturing Processes》2016,31(12):1613-1620
It has been a challenge to finish optical glass surfaces due to their hard and brittle nature. Moreover, tight tolerances of surface figure and finish make polishing a more critical operation. This work reports the results of an experimental study performed for full aperture polishing of BK7 optical glass. Flat samples of borosilicate (BK7) glass are polished using an optical pitch polisher and cerium oxide (CeO2) slurry. Taguchi's L9 orthogonal array is used for the design of experiments. Abrasive concentration, pressure and overarm speed are considered as variable process parameters. Polishing is performed for duration of 120 minutes for each combination of parameters. Material removal is measured using the precision weighing balance. Surface roughness was measured using a Form Talysurf PGI 120 profiler. Abrasive slurry concentration is observed to be one of the most significant parameters in the optical polishing process. It affects both the material removal rate (MRR) and the surface roughness. Pressure applied at the workpiece–polisher interface affects the MRR, but the variation of pressure is not found to affect the surface roughness significantly. Relative motion at the workpiece–polisher interface is also observed to be significant in defining the final polishing outputs. 相似文献