化学法制备纳米氧化物及其EXAFS特征

利用化学方法合成了纳米Ｙ２Ｏ３和纳米ＺｒＯ２颗粒（晶粒的平均大小为２５ｎｍ和１４ｎｍ），并制得了相应氧化物的纳米压结块。探讨了纳米氧化物颗粒被压结成型的各种影响因素。对不同成型压力及不同尺寸纳米氧化物的ＥＸＡＦＳ（扩展Ｘ射线吸收精细结构）谱特征进行了，工与纳米金属的ＥＸＡＦＳ谱特征进行了比较。结果表明，纳米氧化物块体中，晶界原子主要由氧原子组成。     

Abnormal growth of Ag3Sn intermetalUc compounds in Sn-Ag lead-free solder

The abnormal growth of Ag3Sn intermetallic compounds in eutectic Sn-3.5% Ag solder was investigated through high-temperature aging treatment. Microstructural evolutions of this solder before and after the aging treatment were observed by optical microscopy and scanning electron microscopy. Precise differential thermal analysis was made to study the changes in enthalpies of the solder under different conditions. The results reveal that the water-cooled solder is in metastable thermodynamic state due to the high free energy of Ag3Sn nanoparticles, which sporadically distribute in the matrix as second-phase. The second-phase Ag3Sn nanoparticles aggregate rapidly and grow to form bulk intermetallic compounds due to the migration of grain boundary between primary Sn-rich phase and the Ag3Sn nanoparticles during high temperature aging treatment.     

石墨烯的概念及其发展

近年来,石墨烯概念受到各国政府、企业和科研机构的广泛关注,有关石墨烯的制备和应用技术也得到了长足的发展。文章旨在通过对石墨烯概念及其发展态势的介绍,使得社会公众对石墨烯技术有进一步的了解,从而更好地推动石墨烯技术的知识普及,推动石墨烯技术的进一步发展。     

Abnormal growth of Ag_3Sn intermetallic compounds in Sn-Ag lead-free solder

Tin-lead solders have been used for some 2000 years and applied widely in the assembly of modern elec-tronic circuits. However, Pb is harmful to the nervous system of human beings and hazardous to the environ-ment. The European Union directive on waste el…     

固相合成纳米NiO微粒

以NiSO4 ·7H2 O和NaOH为原料 ,用固相法合成了NiO纳米微粒 .研究了不同焙烧温度及同一温度下不同焙烧时间对NiO纳米微晶的晶化过程的影响 .用X射线衍射、透射电镜、热重、差热分析等方法研究了样品的性能 .结果表明 ,固相法可以制得平均粒径为 5nm的NiO纳米微粒 ,属六方晶系 ,形状为球形 .     

浅谈DL纳米改性聚氨酯防水材料在工程中的应用

针对厨房、卫生间屋顶长期漏水的难题，研究了一种将DL纳米改性聚氨酯防水材料的理论与实践、技术与操作成功地融为一体，从而形成完整的施工过程的质量控制方法，并对DL纳米改性聚氨酯防水材料在工程中的应用情况做了具体介绍。     

纳米MnO2粉末的固相合成及其电化学性能的研究

利用固相氧化还原反应制备出纳米级α－ＭｎＯ２超微粒子,并结合透射电镜（ＴＥＭ）,Ｘ射线衍射（ＸＲＤ）,热重量和差热分析（ＴＧ／ＤＴＡ）以及循环伏安（ＣＶ）恒流放电等测试手段对微粒的形貌,粒径大小,热稳定性及其电化学性能进行了表征和讨论。     

Increased osteoblast adhesion on nanophase Ti6Al4V

The objective of the present study was to prepare a novel nanostructured surface of Ti6Al4V alloy by the severe plastic deformation （SPD） and the chemical treatment process and to evaluate the adhesion of osteoblast on the nanophase titanium alloy. In the in vitro study, the primary cultured osteoblasts of neonatal rat calvaria were cultured on the nanophase and the as-received smooth Ti6AI4V substrates. Then osteoblasts adhesion behaviors on different substrates were observed by the fluorescence microscopy, scanning electron microscopy （SEM） and RT-PCR analysis. The results of our research showed increased osteoblast adhesion on the nanophase titanium alloy compared with the as-received case. On the nanophase substrate, the presence of extensive filopodia, strong cellular adhesion and early cellular confluency could be observed. In addition, the expression of the adhesion-related integrin β1 mRNA was also higher on the nanophase substrate. It suggested that the nano technology could be further considered for orthopedic implant applications.