Bioactive Ca-P scaffolds used for bone reconstruction

1　INTRODUCTIONSkeletalreconstructionorregenerationisre quiredincasesinvolvinglargedefectscreatedbytu morresection ,trauma ,andskeletalabnormalities .Graftsandflapsofautogenoustissuearetwoofthemostsuccessfulmeansofreconstructionbecausetheyallowthetransplantationofbonecontainingbioactivemolecules,livecells ,andfrequently ,avascularsup plythatallowthetransplanttosurviveandremodeleveninhostileradiatedenvironments .However ,onlyaminimalamountoftissuecanbeharvestedforauto grafts,anditisverydiff…     

Suspended electrode kinetics of mechanically activated pyrite

1　ＩＮＴＲＯＤＵＣＴＩＯＮＭｅｃｈａｎｉｃａｌａｃｔｉｖａｔｉｏｎｉｓｗｉｄｅｌｙａｐｐｌｉｅｄｉｎｅｎ ｈａｎｃｉｎｇｍｅｔａｌｌｕｒｇｉｃａｌｐｒｏｃｅｓｓ[1～ 3] ａｎｄｃｈｅｍｉｃａｌｓｙｎ ｔｈｅｓｉｓ[4 ,5] .Ｓｏｆａｒｉｔｉｓｄｉｆｆｉｃｕｌｔｔ     

HA-Ti和HA-BG-Ti复合生物材料的力学性能和微观结构

研究了不同成分HA—Ti和HA-BG—Ti复合生物材料的烧结收缩率、微观结构、物相结构与力学性能之间的关系。结果表明：当钛含量达到45％～65％时，HA-Ti系复合材料的抗压强度达到最低值76MPa左右，呈谷值分布．而HA—BG—Ti系复合材料的抗压强度却达到最大值180MPa左右，呈峰值分布；HA—Ti系复合材料的抗弯强度为58～79MPa，而HA-BG—Ti系复合材料的抗弯强度在钛含量为45％～65％时出现最大值164MPa；HA-BG—Ti系的抗压强度和抗弯强度均高于HA—Ti系的抗压强度和抗弯强度。物相分析和微观结构分析表明：HA-BG—Ti复合陶材料中的HA-Ti相间界面依靠生物玻璃以复杂的强键相结合，是HA—BG—Ti系复合材料的力学性能优于HA-Ti二元系复合材料力学性能的原因。     

铕三元配合物的合成、表征及其光致发光性能

以苯甲酸、邻苯二甲酸、间苯二甲酸、水杨酸、丙烯酸、甲基丙烯酸、α—噻吩基三氟甲酰丙酮为第一配体,二安替比林甲烷,三正辛基氧化膦、2,2’-联吡啶、邻菲咯啉及邻菲咯啉N-氧化物为第二配体,合成了系列铕三元配合物。经元素分析确定了它们的组成;研究了它们的紫外吸收光谱、红外吸收光谱及荧光光谱。紫外光谱的研究表明,配合物的紫外吸收主要表现为配体的吸收,但是吸收峰的位置发生了移动;红外光谱的研究表明,配合物的红外光谱不同于自由配体的红外光谱,在400~500 cm-1出现了吸收峰,这是Eu-O的伸缩振动峰;荧光光谱的研究表明,第二配体的加入可以显著提高配合物的荧光性能。     

Physico-chemical properties and microstructure of hydroxyapatite-316L stainless steel biomaterials

Sintering shrinkage, compressive strength, bending strength, metallurgical morphology, microstructure and chemical composition diffusion of hydroxyapatite-316L stainless steel(HA-316L SS) composites were investiga-ted. The results show that the sintering shrinkage of HA-316L SS composites decreases from 27.38O/6o to 8.87% for cylinder sample or from 27.18% to 8.62% for cuboid sample with decreasing the volume ratio of HA to 316L SS,which leads to higher sintering activity of HA compared with that of 316L SS. The compressive strength of HA-316L SS composites changes just like parabolic curve (245.3→126.3→202.8 MPa) with reducing the volume ratio of HA to 316L SS. Bending strength increases from 86.3MPa to 124. 2 MPa with increasing the content of 316L SS. Furthermore, comprehensive mechanical properties of 1.0：3.0 (volume ratio of HA to 316L SS) composite are optimal with compressive strength and bending strength equal to 202. 8 MPa and 124. 2 MPa, respectively. The microstructure and metallurgical structure vary regularly with the volume ratio of HA to 316L SS. Some chemical reaction takes place at the interface of the composites during sintering.     

烧结铜基多孔毛细芯的孔隙特征及性能

以Na Cl为造孔剂,采用粉末冶金法制备具有高孔隙率的铜基多孔毛细芯材料,研究造孔剂粉末含量及粒度对毛细芯材料孔隙率、孔隙微观结构、等效孔径大小、渗透性能及抽吸性能的影响,并讨论孔隙结构、等效孔径及性能的关系。研究结果表明:随造孔剂含量增加,材料的孔隙率明显上升,材料内部的预制孔洞数量显著增加,使得许多预制孔洞相互贯通;减小造孔剂粒度会小幅度降低材料的孔隙率,同时使材料内部预制孔洞尺寸明显变小且分布趋向于均匀;毛细芯材料内部的间隙孔洞和预制孔洞可以组成不同类型的孔道,等效孔径大小与材料内部孔道结构及数量密切相关;通过改变造孔剂的含量和粒度,产生不同孔隙结构,可调控材料的等效孔径大小及分布;毛细芯的渗透性能及抽吸性能不仅仅由孔隙率决定,也与材料的孔结构、孔径大小及分布密切相关;孔隙率越高、平均等效孔径越小且孔径分布越集中的毛细芯,其毛细抽吸性能越好。     

TiO2纳米管薄膜的屈曲图样（英文）

采用基体应变测试方法研究TiO2纳米管薄膜的屈曲图样。结果表明：TiO2纳米管薄膜室温样、250℃退火样和 400℃退火样的屈曲应变依次为2.5%、8.9%和7.8%,说明退火改善了纳米管薄膜/Ti 基体界面状况。从 SEM 观察可以看出,TiO2纳米管薄膜室温样、250℃退火样和400℃退火样的临界屈曲应力分别为180.4、410.2 和 619.5MPa;从 AFM 观察可以看出,TiO2纳米管薄膜 250℃退火样的临界屈曲应力为470.2MPa,两者吻合得很好。采用AFM计算250℃退火样的真实应力和能量释放率分别为840.3MPa和77.2J/m2,此结果与从裂纹角度计算出的250℃退火样的能量释放率102.6 J/m2吻合得很好。     

TiO2纳米管薄膜的脱层现象（英文）

分别通过曲率法和基体拉伸应变测试方法研究TiO2纳米管薄膜的残余应力和脱层行为。结果表明:TiO2纳米管薄膜的内残余应力为-54MPa。TiO2纳米管薄膜室温样、250°C退火样和400°C退火样的脱层出现点的应变依次为2.6%、5.1%和8.6%,半径依次为27.5、17.1和19.4μm。TiO2纳米管薄膜室温样、250°C退火样和400°C退火样的真实临界脱层应力为220.4、394.5和627.9MPa。在脱层条件下,对界面剪滞模型进行修订,并对TiO2纳米管薄膜界面剪切强度进行多项式拟合。由于拟合结果与裂纹密度的分析结果能很好吻合,因此界面剪滞模型的修订方程和多项式拟合方程均为可信的。     

316L纤维尺寸和含量对HA-ZrO2(CaO)/316L纤维复合生物材料性能的影响

研究了316L纤维的长度、直径与含量对HA-ZrO_2（CaO）/316L纤维生物复合材料的力学性能的影响规律.结果表明：纤维直径为40μm的复合材料力学性能优于纤维直径为50μm的复合材料;纤维长度为0.8～1.2mm的复合材料力学性能优于纤维长度为2～3mm的复合材料;随着纤维体积分数增大,纤维之间相互接触而导致在复合材料中形成的微孔增多,并成为微裂纹源,导致材料力学性能下降.含20vol%直径为40μm、长度为0.8～1.2mm的316L纤维的HA-ZrO_2（CaO）/316L纤维生物复合材料的综合力学性能最佳,其抗弯强度、杨氏模量、断裂韧性和相对密度分别为140.1MPa、117.8GPa、5.81MPa·m~（1/2）和87.1%.复合材料微观组织随HA粉末和316L纤维成分的变化呈规律性变化,没有出现明显的裂纹或孔隙,316L纤维与HA-ZrO_2（CaO）基体紧紧地咬合在一起,其结合主要靠基体对316L纤维的物理附着力所致.基体中发生微量Fe元素扩散,但在316L纤维中不发生基体Ca、P元素的扩散.含5%316L纤维复合材料表现为脆性断裂,而含10%、20%、40%316L纤维复合材料均表现为韧性断裂,且韧性程度随316L纤维含量的增加而增大.     

Viscoelastic properties of monodisperse spherical silica suspension

The viscoelastic properties of the suspension of monodisperse spherical silica produced by hydrolysis of tetraethoxysilane in alcohol solvent with ammonia as a catalyst in polyethylene glycol (PEG) were studied. The results show that the SiO2/PEG suspension possesses the reversible shear thinning and shear thickening behaviors. In the shear thinning region, the loss modulus (G″) almost remains unchanged, whereas the storage modulus (G′) decreases. In the shear thickening region, G″ and G′ increase for the formation of the "clusters". The larger G″ over G′ in all the stress studied shows that the system mainly possesses the viscous property, and that the energy dissipated(Ed) is larger than that stored. Ed of this suspension is proportional to the maximum strain (γmax) rising with the exponent of 1.92 under low shear stress; however, in the shear thickening region, Ed is proportional to γmax rising with the exponent of 5.00.