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采用电泳沉积方法在钛基材表面制得羟基磷灰石(hydroxyapatite,HA)/葡萄糖复合涂层,经烧结处理得到多孔HA涂层。采用红外光谱仪、扫描电镜、X射线衍射和热重分析表征了涂层的组成、表面形貌、物相组成及热稳定性,黏结-拉伸实验测定涂层与基体的结合强度,人体模拟体液(simulated body fluid,SBF)浸泡测定涂层的生物亲合性。结果表明:经700℃烧结处理,复合涂层中的葡萄糖微粒热分解得到多孔HA涂层,孔径为2~20μm,涂层与基体的结合强度可达17.6MPa;在1.5倍SBF(各离子浓度为SBF的1.5倍)中浸泡5d后,多孔HA涂层表面碳磷灰石化,呈现良好的生物亲合性。 相似文献
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以多孔聚氨酯泡沫为基体,经过预处理、电化学沉积等工艺制备了具有三维多孔网状结构的、高空隙率的羟基磷灰石泡沫复合材料,将羟基磷灰石涂层浸泡在模拟体液SBF中进行浸泡实验,通过扫描电子显微镜(SEM)、X射线衍射(XRD)和红外分析仪(FTIR)等技术对羟基磷灰石涂层进行了表征。实验结果表明:在合适的条件下可得到纯羟基磷灰石涂层;随着温度的升高,晶体端面边长和长度逐渐增大;涂层在模拟体液SBF中浸泡24h后,涂层表面生成了很多球状磷灰石颗粒相互堆积,磷灰石颗粒尺寸明显增大。 相似文献
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通过酸碱处理活化NiTi合金表面,在模拟体液中仿生生长类骨磷灰石层以改善其生物相容性.采用电化学阻抗谱研究了预钙化对加速磷灰石沉积的影响,并基于双层模型建立了电子等效电路.结果表明:随着在模拟体液中浸泡时间的延长,化学处理的NiTi合金表面类骨磷灰石不断生长,并且添加预钙化试样浸泡3 d,即可在合金表面生长出均匀完整的类骨磷灰石层,而未预钙化试样表面沉积物稀少.对应电子等效电路中,预钙化试样电阻值明显大于未预钙化试样的,显示预钙化促进了活化NiTi合金表面类骨磷灰石的生长. 相似文献
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用模拟体液(simulated body fluid,SBF)作为固化液,对磷酸四钙(TTCP)+一水磷酸二氢钙(MCPM)+β-磷酸三钙(β -TCP)系骨水泥理化性质进行研究.结果表明,随液固比增大,抗压强度先增加后降低,当液固比为0.445时,抗压强度达到最大值15.23 MPa;骨水泥固化较快,液固比为0.594时,t_f为12 min;随着浸泡时间的增加抗压强度逐渐减小;X射线(XRD)和扫描电镜(SEM)分析结果显示,随液固比改变,固化反应结晶物均有羟基磷灰石(HA)相出现;浸泡后的骨水泥没有新物相产生. 相似文献
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富含钙磷的多孔氧化钛膜及其生物活化机理 总被引:10,自引:3,他引:7
在不同电压下,钛经微弧氧化在表面形成富含钙磷的多孔氧化钛膜。通过模拟体液浸泡实验检测磷灰石的形成以确定样品的生物活性。实验结果表明:不同电压制备的微弧氧化样品在模拟体液浸泡后,只有400 V和450 V的样品表面生成磷灰石层,说明高电压制备的样品具有生物活性;而低电压制备的微弧氧化样品在模拟体液中浸泡长达50 d仍未见到任何物质沉积,表明其不具有生物活性。分析认为,粗糙多孔的表面虽有利于磷灰石的成核,但高电压下出现的CaTiO_3相及其水解吸引钙、磷沉积才是磷灰石形成的主要原因。 相似文献
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《高科技纤维与应用》2009,(5)
本发明公开的表面仿生矿化涂层碳纤维增强聚乳酸材料的制备方法,其步骤为:先将碳纤维置于5倍浓度的模拟体液中浸泡,得到表面具有羟基磷灰石涂层的碳纤维;然后将丙交酯、表面具有羟基磷灰石涂层的碳纤维和辛酸亚锡催化剂 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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D. G. Gordeev L. F. Gudarenko M. V. Zhernokletov V. G. Kudel’kin M. A. Mochalov 《Combustion, Explosion, and Shock Waves》2008,44(2):177-189
A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation
of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from
the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO2) of density 0.08 g/cm3.
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Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008. 相似文献
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Jorge Marcelo Romero Soledad Bustillo Hugo Enrique Ramirez Maisuls Nelly Lidia Jorge Manuel Eduardo Gómez Vara Eduardo Alberto Castro Alicia H. Jubert 《International journal of molecular sciences》2007,8(7):688-694
A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out. 相似文献
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A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%. 相似文献
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醋酸纤维素取代基分布与性质的关系 总被引:9,自引:0,他引:9
分析了以吡啶为溶剂的醋酸纤维素的13C-NMR核磁共振谱,得出了三种不同位置羟基的取代度。结合X—射线和DSC分析,初步说明具有相同取代度但未经水解和经过水解的醋酸纤维素(CA) 性质上的差异是由于三个羟基上的取代度分布不同及消晶程度差异所致。 相似文献