Non-invasive Raman identification of crystalline and glassy phases in a 1781 Sèvres Royal Factory soft paste porcelain plate

A Raman study of a Sèvres soft paste (frit) porcelain plate allowed the identification of both the crystalline and amorphous phases. Cristobalite and pseudowollastonite gave main Raman signatures in the body where also tridymite, amorphous alkali silicate glass and lead arsenate apatite were detected. Na_0.4K_0.1Ca_0.5Pb₄(AsO₄)₃ lacunar apatite is identified as opacifier in blue and green overglaze enamel. Pb-Sb-reach pyrochlore (Naples Yellow) pigment was found in yellow and green overglaze enamels. The orange hue is obtained by superposing a hematite bearing red paint stroke over the yellow. These results are compared to those previously obtained by detailed OM, SEM, XRD and XRF analyses. Some of the phases identified by XRD (quartz, tridymite) are hardly detected by Raman and vice versa cristobalite was not found by XRD, most probably due to its low amount.     

Formation of strontium-yttrium germanium anionic lacunar apatite (Sr2+δY6.67+(2δ/3)[GeO4]6O2δ) as the intermediate phase of oxygen-rich yttrium-germanium apatite (Y9.333+ε[GeO4]6O2+3/2ε)

The formation of metastable strontium-yttrium(III) (hexakis) germanium(IV) lacunar apatite (P6₃/m, a=11.426 Å, c=8.224 Å and Z=2) was observed during the thermal treatment of SrCO₃, Y₂O₃, and GeO₂ powder precursors using the ceramic method in an oxygen atmosphere. The utilization of an oxygen atmosphere restricts the extensive reduction of GeO₂ and enables us to explain a new potential mechanism for the stabilization of lead-free lacunar apatites. This mechanism involves the use of electrons localized in a neighborhood of oxygen vacancies. Charged vacancies serve as active sites for the ionosorption of oxygen molecules and their subsequent transformation into lattice oxygen anions, which fill the vacancies at the X-site. The estimation of system thermodynamics shows that apatite undergoes a transformation to a more stable state at δ≥0.1, i.e., at the value that corresponds to the composition of prepared apatite. As the temperature and time of the thermal treatment increases, the process of incongruent melting leads to the formation of oxygen-rich yttrium-germanium apatite (YGAp, Y_9.333+ε[GeO₄]₆O_2+3/2ε) and strontium-yttrium-germanium glass. The YGAp phase is also formed during the annealing of lacunar apatite in an oxygen atmosphere.     

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...     

塔北中新生代构造演化与砂岩型铀成矿作用关系——来自磷灰石裂变径迹的证据

塔里木盆地北部萨瓦甫齐及塔里克地区4个样品的磷灰石裂变径迹测年以及热史反演结果显示,两个地区的隆升时代不同,其中萨瓦甫齐地区裂变径迹年龄为3.5～3.9 Ma,而塔里克地区的裂变径迹年龄为53～59 Ma.热史分析揭示出岩体至少记录了自晚白垩世以来的3个显著冷却阶段.同时,结合前人对塔北中新生代隆升剥蚀研究结果,重点对塔北地区中新生代构造隆升阶段进行了详细研究与划分,结合新疆中新生代砂岩型铀成矿年龄,提出了对塔北地区中新生代构造演化与砂岩型铀成矿作用的新认识.     

氟氯磷灰石固溶体晶体性质的密度泛函理论研究

基于密度泛函理论(DFT)研究了氟磷灰石、氯磷灰石及不同Cl含量的氟氯磷灰石固溶体晶体结构和电子性质。结果表明, 随着Cl含量增加, 体系能量趋于增大, 同时晶体结构中a, b值呈增大趋势, c值却逐渐变小。态密度分析显示, Cl取代F后, Cl 3s态较F 2s态向右移动, 且在价带顶部Cl 3p态更靠近费米能级, 同时峰费米能级附近Ca₂ 3d态也更活跃。电荷分析显示Cl取代F后, 主要电荷转移发生在通道原子F、Cl以及金属Ca; Mulliken键布居显示Ca₂-Cl较Ca₂-F键布居值更大且键长更长, 其中在氯磷灰石中Ca₂-Cl键长达到了0.2608 nm。     

青海低品位磷灰石型磷矿浮选试验研究

对青海某低品位磷灰石型磷矿进行了浮选试验研究。原矿经粗磨后, 可抛除约20%的粗粒黑云母和透辉石。抛尾后试样经再磨后, 采用氧化石蜡皂和2^#药作为捕收剂, 在无碱条件下, 开路试验获得的磷精矿P₂O₅品位为35.41%、P₂O₅作业回收率为87.24%。闭路流程试验获得了磷精矿P₂O₅5 32.01%、P₂O₅作业回收率达97%的良好结果。采用可溶性淀粉可有效抑制磷精矿中的含镁矿物, 从而获取合格的磷精矿。     

电感耦合等离子体质谱法测定磷灰石中稀土元素分量和总量

基于电感耦合等离子体质谱法(ICP-MS)在稀土元素分析方面的优势,以HCl、HNO₃、HF和HClO₄溶解样品,控制He气流量为4.70 mL/min,实现了动能歧视碰撞池(KED)-ICP-MS对磷灰石样品中稀土元素分量和总量的测定。通过选择合适的同位素避免了质谱干扰;通过稀释基体质量浓度不大于0.25 mg/mL和选择45 ng/mL¹⁸⁵Re为内标进行校正相结合的方法消除了非质谱干扰。实验表明,在选定的实验条件下,各稀土元素在0～100 ng/mL范围内与其对应的质谱强度呈良好的线性关系,校准曲线相关系数r为0.999 0～0.999 9,方法检出限为0.000 1～0.019 2 ng/mL。将实验方法应用于磷灰石实际样品中稀土元素分量和总量的测定,所得结果的相对标准偏差(RSD,n=6)为1.1%～4.7%,加标回收率为96%～109%。     

蓬莱9-1构造新生代构造演化:磷灰石裂变径迹证据

作为国内最大的中生界花岗岩潜山油田,蓬莱9-1构造中生界花岗岩的构造演化直接制约着储层的分布及好坏,而区域构造演化证实花岗岩在整个新生代经历了长期的暴露和改造过程。通过磷灰石裂变径迹技术对该构造中生界花岗岩新生代的构造演化进行了详细研究,结果表明该构造新生代热史分为4个降温期和2个升温期共6个阶段,结合区域构造背景可将新生代构造演化进一步划分为稳定期(65~51 Ma)、低速隆升期(51~34 Ma)、高速隆升期(34~18 Ma)、沉降期(18~5 Ma)和成藏期(5 Ma至今)5个阶段。不同隆升期花岗岩剥蚀速率存在明显差异,其高速隆升期剥蚀速率可达110.7 m/Ma,新生代平均剥蚀量约2 260 m。成藏研究证实构造演化与花岗岩成储成藏有着密切联系,隆升期的风化壳形成和沉降期的泥岩沉积使花岗岩具备了良好的储盖组合,成藏期的新构造运动又为油气的运移和充注提供了有利条件。     

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.