Apatite crystal in hard tissue of conodont fossils

The present study was aimed at examining the nature of apatite crystal in the tooth apparatus of a conodont fossil using transmission electron microscopy (TEM), scanning electron microscopy (SEM), laser Raman microprobe spectrometry and electron-probe microanalysis (EPMA). The hard tissue of the condont consisted of 2 layers and the organization varied with the size of the crystal. Higher magnification showed that the crystals were observed in the lattice of (100) and the central dark lines were not present. Ca, P, and F were detected in the crystal using EPMA. Our results indicate that the apatite crystal in conodont fossils is not hydroxyapatite but fluorapatite.     

Growth kinetics of apatite layer evolved from calcia-magnesia-aluminosilicate (CMAS) hot corrosion reaction of (Y1-xYbx)2SiO5 ceramics at elevated temperatures of 1673 K and 1773 K

Calcia-magnesia-aluminosilicate (CMAS) corrosion behaviors of hot-pressed (Y_1-xYb_x)₂SiO₅ ceramics at 1673 K and 1773 K have been investigated. The main corrosion product of nonstoichiometric Ca-RE-Si-O apatite phase evolves with increasing temperature or prolonging corrosion time. The growth of apatite layer at 1673 K follows approximately a linear rate law, however it follows a proximately parabolic rate law at 1773 K. The growth rate of the apatite layer at 1773 K is lower than that at 1673 K in the process of interaction between CMAS and rare-earth monosilicates. Yb-doping mediates the CMAS corrosion resistance of Y₂SiO₅ effectively by changing the growth rate of apatite layer and the composition of formed apatite phase. This work provides new insights on compositional regulation of (Y_1-xYb_x)₂SiO₅ EBCs materials to resist CMAS corrosion.     

One-step synthesis of petal-like apatite/titania composite coating on a titanium by micro-arc oxidation

Petal-like apatite/titania (TiO₂) coating was prepared on commercially pure titanium (Ti) by micro-arc oxidation in electrolyte containing calcium and phosphate for the first time. The surface morphology, crystalline structure, chemical composition and binding state of the apatite/TiO₂ composite coating were characterized. The coating consists of a double-layer (apatite layer and TiO₂ layer) structure. The average thickness of the inner TiO₂ layer and the outer apatite layer is about 6 μm and 16 μm respectively. The outer apatite layer is porous and exhibits petal-like pattern. The apatite layer consists of hydroxyapatite (HA) and carbonate-apatite and the inner TiO₂ layer consists of anatase and rutile.     

预处理对构建丝素蛋白纤维/磷灰石仿生骨修复材料的影响

利用氯化钙-乙醇-水(n(CaCl2):n(EtOH):n(H2O)=1:2:8)三元溶液对丝素蛋白纤维预处理,再采用交替浸渍法将其分别浸在钙溶液和磷溶液中交替浸渍、仿生矿化制备丝素蛋白纤维/磷灰石复合材料,采用SEM、FTIR、XRD和TGA等技术研究了不同预处理时间对丝素蛋白纤维微结构和构建丝素蛋白纤维/磷灰石的影...     

TiO2纳米管表面蛋白质-羟基磷灰石复合涂层及其结合强度

采用阳极氧化法在钛表面制备不同管径的TiO2纳米管,450℃热处理后经牛血清白蛋白(BSA)与钙磷的共沉积得到载有BSA的羟基磷灰石(HA)涂层.经检测发现,170nm管径的TiO2表面比100和50nm管径的表面具备更好的矿化能力,HA的形成能力随管径的增大而提高.大管径表面得到的涂层结合强度高于小管径的,可达16.95MPa.经过真空预矿化的试样,涂层结合强度明显高于未经过预矿化的试样,且HA涂层生长速率加快.BSA与磷酸钙在真空预矿化后共沉积到氧化钛纳米管表面,短时期内形成BSA-HA涂层,是在钛基生物材料表面制备生物活性涂层的有效方法.     

预钙化处理后的钛表面磷灰石涂层的形成

本研究采用碱液处理钛样品 ,并进行预钙化处理 ,在模拟体液 (SBF)中浸泡 ,能在较短时间内形成表面致密的磷灰石涂层。碱液处理使钛表面生成了钛酸钠及氧化钛等物质 ,在SBF中浸泡时 ,会发生水解而使表面形成带负电的Ti OH基团。预钙化处理使带负电的钛表面由静电引力而聚集了大量的Ca2 + 离子。Ca2 + 能吸引带负电的HPO2 -4到达表面 ,从而使表面附近能在较短时间内达到钙 磷过饱和。Ca2 + 离子又能使表面附近的pH值增大 ,Ca2 + 离子和HPO2 -4离子的活度积就增大 ,从而刺激了磷灰石晶体的成核与长大 ,最终形成表面磷灰石涂层     

应用磷灰石裂变径迹定量恢复热演化史

本文应用磷灰石裂变径迹的面积径迹数随时间，温度变化的规律，建立非线性热流的反演模型。进行了海拉尔盆地２口井的地热史模拟，得到对盆地古热流演化及烃源岩热演化一般规律的认识，为进一步了解其油气生成条件提供了定量依据。     

组合药剂DMF-1对朝阳某磷矿浮选试验研究

本文在油酸钠、十二烷基磺酸钠、DES对朝阳某磷矿捕收性能试验的基础上组合出一种新型药剂DMF-1,并以此为捕收剂进行了浮选工艺技术条件试验及开路试验。在磨矿细度-0.074mm46%,矿浆pH值7.00,DMF-1用量200g/t,温度30℃,水玻璃用量400g/t,采用一次粗选、三次精选、一次扫选的试验流程,获得磷精矿品位36.46%、回收率53.33%,尾矿品位0.21%的指标,表明捕收剂DMF-1具有药剂制度简单、用量少、无需矿浆加热、捕收效果好的特点。对试验结果分析,研究了DMF-1中三种成分之间的协同效应和作用机理,其中十二烷基磺酸钠主要是起泡作用;油酸钠则以化学吸附在矿物表面起到疏水及捕收作用;DES以化学吸附和氢键吸附协同作用的方式,增强药剂DMF-1的捕收性能。     

固体氧化物燃料电池电解质材料的研究进展

介绍了固体氧化物燃料电池(SOFC)用萤石型、钙钛矿型及磷灰石型电解质材料的结构、导电机理、性能及研究进展。存在的离子电导率较低、化学组成及相组成不稳定等问题,主要通过氧化物共掺杂及不同材料之间的复合等方法来改善。材料的复合与电解质层结构的设计,将成为电解质研究的主要方向。     

Luminomagnetic Nd3+ doped fluorapatite coated Fe3O4 nanostructures for biomedical applications

Luminomagnetic nanostructured Nd³⁺ doped fluorapatite (FAP) coated Fe₃O₄ nanoparticles were produced by hydrothermal method. X-ray diffraction analysis indicates that the prepared nanoparticles contain both FAP and Fe₃O₄ phases. Electron microscope analysis shows the formation of nanoparticles of Fe₃O₄ encased in rod shaped FAP nanoparticles of average length 40 nm. Magnetic measurements confirm the room temperature superparamagnetic nature of the nanoparticles with saturation magnetization value up to 7.8 emu/g. The prepared nanoparticles display strong near infrared (NIR) emission at 1060 nm under 800 nm excitation. Cell viability studies for 72 hour demonstrate the survival rate of over 84% with 500 μg/mL concentration indicating the good cytocompatibility of the prepared materials. The present Nd³⁺ doped FAP coated Fe₃O₄ nanostructure provides an excellent multifunctional platform for diagnostics and therapeutic applications.