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1 INTRODUCTION That crystal is the internal particles arranged re- peatedly and periodically in three-dimensional space or the solid with space lattice structure is the com- plete definition of crystal at absolute zero tempe- rature[1, 2]. But actual crystals deviate from the ideal ones in certain degree because of various influences, such as the impurity and thermal vibration of crystal particles, which is called crystal structural defect. Strictly speaking, all factors causing the crysta… 相似文献
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以g-C_3N_4和BiVO_4为主要原料,用高温水热法合成出BiVO4/g-C_3N_4复合催化剂。采用X-射线衍射(PXRD)和紫外-可见漫反射吸收光谱(UV-Vis),对复合催化剂BiVO_4/g-C_3N_4的结构进行表征。在可见光下,考察此复合催化剂对亚甲基蓝的降解性能。研究发现,复合催化剂具有g-C_3N_4和BiVO_4结构特征,在X-射线衍射峰上显示出轻微的宽化,质量比为10%的BiVO_4/g-C_3N_4光催化剂降解活性最好,其降解率在360分钟能达到70.6%。 相似文献
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β-Na YF4:Yb3+,Er3+ microrods with average length of 10 μm and diameter of 2.5 μm were synthesized through hydrothermal method. Based on the obtained microrods, transparent and flexible film with upconversion luminescence property was prepared through inorganic-organic composition method by using co-polymerization product of isobornylmethacrylate and urethane acrylate as the polymer substrate. The prepared film shows excellent optical transmission in the visible region with average transmission of 81.3% at high doping concentration(2 wt%) of β-Na YF4:Yb3+,Er3+ microrods. By directing and moving NIR laser beam toward the prepared film with high scanning speed, visible light is effectively emitted and various images are able to display. 相似文献
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提出了固相萃取-高效液相色谱法测定水中3种磺胺类药物(磺胺甲噁唑、磺胺异噁唑和磺胺间甲氧嘧啶)的方法。水样经自制的阳离子交换固相萃取柱净化和富集后,以C18色谱柱(250mm×4.6mm,5μm)为固定相,以乙腈和2%(体积分数)乙酸溶液以体积比1比5的混合液为流动相进行分离,在波长270nm处用紫外检测器测定。3种磺胺类化合物的质量浓度均在0.005~0.5mg.L-1之间与其峰面积呈线性关系,方法检出限(3S/N)在2.4~3.7μg.L-1之间。方法用于水样中上述3种磺胺类化合物的测定,测定值的相对标准偏差(n=6)在2.6%~4.4%之间,加标回收率在88.6%~103%之间。 相似文献
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铝厂污泥在不同煅烧温度的晶相结构研究 总被引:31,自引:2,他引:31
铝厂污泥主要成分是-AlOOH,其中部分是晶体,部分是无定形体。将此污泥分别于450,600,800,1000,1050,1200和1300 ℃进行了煅烧,探讨污泥在不同温度下的晶相变化,为污泥的综合利用提供可靠的数据。采用XRD法和SEM法表征了污泥在不同温度下的晶相结构和显微结构。实验结果表明:随着煅烧温度的提高,污泥发生如下变化过程: 这与常规转化规律不同。在450,600,800,1000和1100 ℃的试样中均形成了-Al2O3和无定形体结构的微晶,随着温度的升高,-Al2O3含量增加而无定形体结构的微晶含量降低。当煅烧温度上升至1200和1300 ℃时, - Al2O3和无定形体结构的微晶全部转变为 - Al2O3。 -Al2O3是介稳态,高活性,-Al2O3是稳定态,低能态。 相似文献
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By adding small amount of TiO2, aluminum slag could be used to synthesize cor-dierite, α-Al2O3, TiO2 and dehydrated talc could generate solid solution to accelerate the solid-state reaction to form cordierite. The experimental results show that the content of cordierite increases with the increase of TiO2 added. 3.0% of TiO2 is determined to be the best amount, because all crystalline substances are converted into cordierite at this content. Philips X‘pert plus software analysis shows that when the content of TiO2 is from 0 to 1.0%, cordierite has the same hexagonal structure as the single crystal and the lattice parameters change slightly; when the content of TiO2 is from 1.0 to 2.0%, the cordierite still keeps hexagonal structure but the lattice parameters change greatly; when the content of TiO2 is from 2.0 to 3.5%, the cordierite is converted from hexagonal into rhombic and the lattice parameters change accordingly. 相似文献
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反应温度与时间对铝型材厂工业污泥合成堇青石材料的得率与晶相结构影响 总被引:4,自引:0,他引:4
本研究主要探讨反应温度和反应时间对铝型材厂工业污泥合成堇青石材料的得率和晶相结构的影响。该污泥系由铝型材表面处理时产生的大量废液, 经沉淀过滤所得。主要成分是一种超细的γ-AlOOH, 其中部分是晶体, 部分是无定形体, 活性很高, 有利于堇青石晶相的形成, 能降低反应温度。 实验结果表明: 堇青石含量随着反应温度升高而增加; 晶相结构和晶胞参数与反应温度有关; 确定1350℃为最佳的反应温度; 反应时间在 2~5 h的试样中,堇青石含量增加, 在5~6 h含量降低. 5 h为最佳的反应时间。 相似文献
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Influence of Cr2O3 on the Structure and Property of Mg-Al Spinel Synthesized by Waste Slag in Aluminum Factory 总被引:1,自引:0,他引:1
Via the solid phase reaction, Mg-Al spinel has been synthesized by using industrial waste slag from aluminum factory, basic magnesium carbonate and a little amount of clay as the main raw materials. The influences of Cr2O3 mineralizer on crystalline structure, micro-morphology and properties of synthesized Mg-Al spinel are discussed. The synthesized product was characterized by using XRD and SEM, and the relative contents of each crystalline phase are calculated by relevant analytical software such as Philips plus, Rietveld quantification and so on. The experimental results show that a certain amount of Cr2O3 is helpful to the formation of Mg-Al spinel, and when the addition of Cr2O3 is 2.0%, Mg-Al spinel in the system exists in the form of solid solution (Mg0.68Al0.32)(Al0.84Mg0.16)2O4 whose content is the highest reaching 91%. Then the corresponding indexes of each property are as follows: water absorption 3.0%, apparent porosity 9.8%, bulk density 3.36 g·cm-3, and flexural strength 83.32 MPa. Therefore, we can confirm that the optimum addition of Cr2O3 mineralizer is 2.0%. 相似文献