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为提高玄武岩纤维(BF)与水泥基体的界面结合力和桥接作用,分别采用HCl溶液(0~2.0mol/L)和NaOH溶液(0~2.0mol/L)对BF表面进行刻蚀糙化处理,研究纤维表面处理对BF增强水泥基复合材料的力学性能影响规律。结果表明:随着HCl溶液浓度增加,BF/水泥复合材料抗折强度与弯曲强度均先增加后降低,挠度呈现缓慢增加趋势,而抗压强度变化幅度较小;当HCl溶液浓度为1mol/L时,BF/水泥复合材料的强度与韧性最佳;碱处理BF后,BF/水泥复合材料的力学性能随NaOH浓度增加而显著降低,且复合材料韧性无明显改善;BF经HCl溶液腐蚀后的质量保留率变化规律与NaOH溶液腐蚀后的变化规律接近,而经HCl溶液腐蚀后BF强度保留率大于NaOH溶液腐蚀后的BF强度保留率。 相似文献
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掺银二氧化钛纳米带的制备及其光催化性能研究 总被引:4,自引:0,他引:4
TiO2纳米带作为一种纳米光催化剂用于污水处理中时,能克服TiO2纳米颗粒不易分离同收等困难,对其进行贵金属掺杂,可提高其光催化活性.本研究以价格低廉的钛白粉为原料,采用水热法制备了掺银的TiO2纳米带,并运用XRD,SEM和EDS等对所制备的样品进行表征,进行了光催化降解甲基橙反应,考察了纳米带中的掺银量,煅烧温度等条件对降解甲基橙反应的影响.结果表明,当TiO2纳米带掺银量为0.1%(质量分数,下同),焙烧温度为700℃,催化剂用量为0.05g,室温下用15W紫外灯光照180min时,掺银的TiO2纳米带对甲基橙的降解率可达98.51%,较掺杂前提高了22%左右. 相似文献
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氮化硼作为催化剂载体可用于高温催化反应,然而常用的块体氮化硼比表面积为25m2/g左右,而现有的高比表面积氮化硼的制备方法操作复杂,经济适用性差,难以实现大量生产。作者采用料浆起泡法制备氮化硼先驱体,然后再将先驱体进行高温氮化处理,最后进行除杂。通过XRD、TEM、SEM、BET对样品进行表征,分析测试结果表明样品是六方氮化硼,比表面积为286.58m2/g,平均孔径为5.314 3nm,属于中孔材料。同时对致孔的机理进行了探讨。 相似文献
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直接荧光分光光度法快速测定水体中叶绿素a 总被引:2,自引:0,他引:2
利用藻类叶绿素a具有强荧光之特性,在激发波长418nm和发射波长680nm的条件下,发现叶绿素a浓度在0.28~88μg/L范围内与其荧光强度之间具有良好的线性关系,进而建立了直接荧光分光光度法测定水体中叶绿素a的新方法。同时以绿藻为例,建立了水样中绿藻所含叶绿素a荧光强度与绿藻生物量之间的相关关系。据此,可采用荧光分光光度法快速实时测定水样中藻类生物量,为藻类暴发的预警工作提供科学依据。将该法与传统萃取-分光光度法进行对比,无显著性差异,用于实际水样测定,结果满意。 相似文献
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Electroluminescence (EL) of organic light emitting diodes (OLEDs) with a configuration of ITO/TPD/BC/Alq3/Mg-Ag, where TPD, BC and Alq3 represent N, N′-diphenyl-N, N′-bis (3-methylphenyl)-1,1′-biphenyl-4,4′-diamine, bathocuproine and tris(8-quinolinolato)aluminum(III),
respectively, was investigated in comparison with the photoluminescence (PL) of the individual organic layers. The EL spectra
of the OLEDs were found to be much different from the PL spectra of the component multiple layer structure. Each organic layer
made its contribution to the light emitted from the OLEDs. Their individual contributions were related to the field distribution
across the device, which was in turn dependent on the thickness of each organic layer and the applied bias voltages. Consequently,
the EL spectra of the OLEDs were observed to vary as the relative thickness of any organic layer was changed and as the bias
voltage was alternated. The variation of the EL spectra of the device resulted in the easiness of achieving variable colors
emitted by the device, from blue to green, and then to near white light.
Funded by the Scientific Research Foundation for the Returned Overseas Chinese Scholars 相似文献