| 1. | Study on pyrochlore in synthesis process of lead - based relaxor ferroelectrics 铅基弛豫铁电材料中的焦绿石相研究 |
| 2. | Aragonite whisker is a kind of mono - crystal fibers , which have excellent properties 文石相碳酸钙晶须是一种性能优异的单晶纤维材料。 |
| 3. | The influence of pellet technique and microwave method on the emerge of the intermediate pyrochlore phase was studied 通过压片煅烧和微波合成等工艺考查了压片及快速升温对焦绿石相的生成的影响。 |
| 4. | Studies on the preparation of aragonite whisker and its growth mechanism are meaningful at theory and practice to develop traditional calcium carbonate industry , new materials and theory of crystal growth 制备文石相碳酸钙晶须的研究对促进我国传统碳酸钙产业、新材料的开发以及晶体生长理论的发展都具有重要的理论意义和实践意义。 |
| 5. | The optimum mole ratio of flux to composition was found to be 6 : 4 , which can restrain the formation of pyrochlore phase . it was revealed that b2o3 additive played an important role in increasing the size of single crystals . 4 助熔剂和组分间的摩尔配比以6 : 4为佳,能够抑制焦绿石相的产生;此外,添加少量的b _ 2o _ 3作助熔剂有利于晶体的长大。 |
| 6. | The results showed that the optimized processing parameters were ph = 9 , concentration of mgcb were 0 . 4mol / l , reaction temperature were 75 c , flow velocity of co2 were 4 . 5ml / min / gcao , stirring strength were 200r / min 实验结果表明制备文石相碳酸钙晶须的最优工艺参数为ph值维持在9左右,反应温度为75 , co _ 2流速为4 . 5ml min gcao ,搅拌速度为250r min 。 |
| 7. | The precursor method could solve the problem that the appearance of pyrochlore phase during the synthesis procedure by avoiding the direct reaction between pbo and nb _ ( 2 ) o _ ( 5 ) . furthermore it also could decrease calcination temperature and pbo volatility 采用二次合成法制备pmn - pt钙钛矿相,避免了pbo和nb _ 2o _ 5的直接反应,从而抑制了焦绿石相的生成。 |
| 8. | Thus , the system could be kept at a lower super - saturation state under the condition of higher concentration of ca2 + to obtain aragonite whisker . the surface of aragonite must be modified to overcome the shortcomings leading to poor dispersion and combination with polymer materials 为了解决作为无机填料由于表面亲水疏油而在聚合物材料内部分散性差、与高聚物本体结合力差等的缺点,必须对文石相碳酸钙晶须进行表面改性。 |
| 9. | In this thesis , the stearic acid and titanate - coupling agent were used to modify the surface of aragonite whisker . the ir - spectrograph analysis and the suspending - experiment showed that the two ingredients were effective to modify the aragonite whisker , and the titanate - coupling agent was better than stearic acid 红外光谱仪分析和悬浮实验表明二者均能有效地对文石相碳酸钙晶须实行改性,且达到完全改性时钛酸酯用量少于硬酯酸。 |
| 10. | In this study , precursors have been prepared by coprecipitation . the precursors prepared by coprecipitation have high purity , homogeneity and reactivity etc . thus it can decrease synthesis temperature and pbo volatility . furthermore the pyrochlore phase is hardly formed during synthesis 通过化学共沉淀法制备前驱体,使各组份能以原子尺度进行混合,提高反应活性,有效降低合成温度,最大限度地减少铅挥发造成的污染,同时避免焦绿石相的生成。 |