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71.
水热法合成NaP1型粉煤灰沸石的性能表征 总被引:8,自引:0,他引:8
通过碱性介质中的水热反应,由粉煤灰合成了单一沸石矿物种的NaP1沸石,并对合成产品进行了表征.经粉晶X射线衍射鉴定,合成产物中主要矿物成分为NaP1沸石,另有少量尚未反应的石英和莫来石.在电子显微镜下,粉煤灰颗粒呈球形且表面光滑,而合成产物颗粒表面粗糙.粉煤灰合成沸石含有大量的交换性Ca2 ,且与粉煤灰原料相比,SiO2含量明显减少,Al2O3稍有增加,SiO2/Al2O3比值由3.3降至1.8.红外光谱分析和差热分析证实了合成的粉煤灰沸石中沸石水的存在.NaP1型粉煤灰沸石的阳离子交换容量(CEC)达213 cmol/kg,比表面积达29 m2/g,分别比粉煤灰高约100倍和26倍. 相似文献
72.
We investigated the effect of controlled damage on the residual strength, failure mechanism and acoustic emission (AE) activity of graphite epoxy composites. The controlled damage was introduced by indenting unidirectional tensile specimens using a hardness machine with a diamond indentor. The specimens were loaded parallel to the fiber direction. The damage progression mechanisms operating upon subsequent loading and the failure modes were found to be different for sound and indented specimens. The difference in mechanical behavior affected also the AE, as displayed by the statistical moments of the peak amplitude distribution. Specifically, the variation of moment values with stress level were found to be different for the two groups. This difference can be used to sort sound from defective material during loading. In addition, this approach can in future be used as a means to ratify the soundness of structures, if a reliable database can be generated. 相似文献
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The crystallography of martensite formed in 0.2C-2.0Mn-1.5Si-0.6Cr steel was studied using the electron backscattered diffraction(EBSD) technique.The results showed that the observed orientation relationship(OR) was closer to that of Nishiyama-Wassermann(N-W) than Kurdjumov-Sachs.The martensite consisted of parallel laths forming morphological packets.Typically,there were three different lath orientations in a morphological packet consisting of three specific N-W OR variants sharing the same {111} austenite plane.A packet of martensite laths with a common {111} austenite plane was termed a crystallographic packet.Generally,the crystallographic packet size corresponded to the morphological packet size,but occasionally the morphological packet was found to consist of two or more crystallographic packets.Therefore,the crystallographic packet size appeared to be finer than the morphological packet size.The relative orientation between the variants in crystallographic packets was found to be near 60 /<110>,which explains the strong peak observed near 60 in the grain boundary misorientation distribution.Martensite also contained a high fraction of boundaries with a misorientation in the range 2.5-8.Typically these boundaries were found to be located inside the martensite laths forming sub-laths. 相似文献
75.
本文采用不同的酸对蜂窝式堇青石进行处理,研究酸蚀处理对其组成和孔结构的影响。并以自制的二氧化硅溶胶为第二载体对酸处理后的堇青石进行涂敷。采用XRD、N2等温吸附-脱附、SEM等手段对二氧化硅进行表征。结果表明:酸蚀处理并不改变堇青石的晶相结构;经酸处理后的堇青石其比表面积有不同程度的增加;而经二氧化硅涂敷后的堇青石比表面积可达93.35m2/g。 相似文献
76.
Nanoparticles of the type M-2411 (with M = U, Nb, Zr, Ag, etc.) can be embedded within the superconducting YBCO matrix to provide flux pinning sites. Among all these types of nanoparticles, the Ag-2411 particles are special in the sense that they may provide also metallic Ag particles to be formed within the superconductor. The addition of metallic Ag (or silver oxide) was shown to be a means to create a more stable system by filling cracks and voids. Using the advanced polishing method of the YBCO surfaces, we achieve a high EBSD image quality of the recorded Kikuchi patterns. In this contribution, we perform a four-phase EBSD analysis including YBa2Cu3Ox, Y2BaCuO5, Ag-2411 and metallic Ag. As a result, we find nanometer-sized Ag particles being distributed within the YBCO matrix, and a reduced amount of Ag-2411 particles as compared to the nominal composition. The Ag-2411 particles are well oriented with the surrounding YBCO matrix as found earlier, but the metallic silver particles as detected by EBSD do not exhibit a preferred orientation. 相似文献
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79.
以辛酸亚锡为催化剂低温常压下引发左旋丙交酯(LLA)开环聚合,快速高效地合成了性能良好的高分子量左旋聚乳酸(PLLA).通过正交实验研究了催化剂用量、反应温度和时间对产物分子量的影响,在催化剂用量0.21%(质量分数),反应温度100℃,反应时间60min时得到产物粘均分子量高达16.21×104.通过红外光谱(FTIR)、核磁共振氢谱(1H-NMR)对产物的结构进行分析,结果证明利用微波能有效地合成左旋聚乳酸,通过差式扫描量热(DSC)、X衍射(XRD)、旋光度和力学性能对左旋聚乳酸膜的性能进行表征,结果显示产物纯净,其结晶度为85.6%,光学纯度为98%,有良好的力学性能. 相似文献
80.
用电解抛光法制备大应变量SWRH82B钢丝EBSD试样 总被引:1,自引:0,他引:1
提出了适合大应变量SWRH82B钢丝的电解抛光工艺参数。用电解抛光法制备该种材料的EBSD试样时,温度、电压和时间均对试样的菊池花样有重要影响。试样去应力退火后再进行电解抛光,可得到更好的花样质量。 相似文献