内掺氧化钡对贝利特型水泥性能的影响

本文应用化学分析、XRD、SEM、EDAX、IR等测试手段,研究了在多种组分存在的条件下,内掺BaO对C_2S-C_4A_3-C_4AF-C系统矿物组成及性能的影响。     

An investigation of trivalent substituted M-type hexagonal ferrite using X-ray and Mössbauer spectroscopy

Series of substituted M-type hexagonal ferrite has been synthesized, and studied by means of X-ray diffraction, IR and Mössbauer spectroscopy. The samples have the formula (BaCr _x Fe_12?x O₁₉) (with x = 0.0, 1.0, 2.0, 3.0, 4.0, and 5.0). X-ray diffraction studies prove that all samples has a single phase M-type hexagonal structure. The lattice parameters both a and c were found to be composition dependent. This observation was attributed to the atomic radii of the substituted cations. The Mössbauer spectra change from magnetically ordered (x = 0) toward magnetically ordered with strong line broadening. The broadening increases as the Cr content increase. Measurements at low temperature (80 K) restore the magnetic order. The Mössbauer parameters suggest that Cr³⁺ prefers to occupy the 4f₂ and 2a crystal sites. IR absorption bands were observed between 1,500 and 400 cm^?1, and confirm the structure in coincidence with X-ray results.     

ChemInform Abstract: Study of Phase Transformation in BaTe2O6 by in situ High‐Pressure X‐Ray Diffraction,Raman Spectroscopy,and First‐Principles Calculations.

The title compound is synthesized by solid state reaction of a stoichiometric mixture of BaCO₃ and TeO₂ (air, 550 °C for 6 h, and 650 °C for 12 h).     

ChemInform Abstract: Crystal Structure and Properties of the Manganese Containing Swedenborgite YBaMn3AlO7.

Small crystals of the title compound are grown from BaAl₂O₄, Y₂BaO₄, and MnO in a floating‐zone mirror‐image furnace.     

制备方法对掺钡纳米氧化镁负载钌催化剂氨合成性能的影响

 采用普通浸渍法 (CI)、超声-包覆法 (UC) 和超声-静电吸附法 (UEA) 制备了 Ru/Ba-MgO 氨合成催化剂, 并运用高分辨透射电镜、场发射扫描电镜、X 射线粉末衍射、N2 的物理吸附、H2 脉冲化学吸附及程序升温还原等手段对催化剂进行了表征. 结果表明, 在 UEA 样品中, Ba 以静电吸附形式均匀地掺入 MgO 载体中, 因而不仅极大地改善了载体表面形貌, 而且有效地控制了 Ru 晶粒大小, 其平均粒径在 2~3 nm. 该样品中, BaCO3 起始分解温度较低, 低温 BaCO3 含量较高, 因而还原性能较佳. 在 10 MPa, 10 000 h?1 和 425 ºC 条件下, UEA 法制得的 Ru 基催化剂上氨合成反应速率达到 60.42 mmol/(g•h), 分别是 CI 法和 UC 法的 1.9 和 1.1 倍.     

铈酸钡和钇掺杂的铈酸钡复合氧化物的制备及其在钌基氨合成催化剂中的应用

 采用柠檬酸法合成了 BaCeO3 和掺杂 Y3+的 BaCe0.9Y0.1O3-δ 复合氧化物, 以 Ru3(CO)12 为前体, 利用浸渍法制备了 Ru/BaCeO3 和 Ru/BaCe0.9Y0.1O3-δ 催化剂. 通过 X 射线衍射、扫描电镜和透射电镜技术对样品进行了表征, 并在固定床反应器中考察了催化剂的氨合成反应活性. 结果表明, 载体 BaCeO3 的稳定性优于 BaCe0.9Y0.1O3-δ, 但 Ru/BaCe0.9Y0.1O3-δ 催化剂的氨合成活性明显高于 Ru/BaCeO3, 在 3.0 MPa, 15 000 h1, 425 oC 反应时, Ru/BaCe0.9Y0.1O3-δ 催化剂上氨合成反应速率达到 432.5 ml/(g•h), 是 Ru/BaCeO3 催化剂的 1.6 倍. 这种活性和稳定性的显著差异来自载体中 Ce4+ 与 Ru 纳米粒子间的电子作用.     

固体高铁酸钡的稳定性研究

经过对固体高铁酸钡在不同温度下的稳定性研究，发现热分解是导致高铁酸钡稳定性较差的重要因素。对该物质进行表面处理和加入微量的添加剂可以明显改善其稳定性。     

立窑内黑生料球的燃烧与反应特性研究

本文通过对黑生料球在不同煅烧温度下的残余碳、失重率及游离氧化钙等的测定,对立窑黑生料球的燃烧与反应特性进行了研究。认为黑生料球的燃烧大致可分为三个阶段。根据实验中游离钙的变化规律,并结合有关煅烧理论,肯定了黑生料煅烧的优越性。而实验中机械不完全燃烧现象,说明了“高灰分”对料球燃烧反应的影响,为实际生产控制提供了依据。     

枝晶簇四方相钛酸钡的制备及其电场响应性能的研究

为了提高BaTiO3粒子在含水复合弹性体中的电场响应能力,本文采用简单的水热合成法,在不引入任何表面活性剂的情况下,仅通过对反应温度和溶液pH值的调控获得了新颖形貌的钛酸钡粒子。通过借助X射线衍射(XRD)、拉曼光谱(Raman)、扫描电子显微镜(SEM)及接触角(Contact Angle)测量等手段对粒子的微观结构和表面特性进行表征发现:该粒子为高纯四方相枝晶簇结构,具有良好的亲水性,而且在含水复合弹性体中对电场具有优良的响应能力。     

Study of the microstructural transformations of borate glass and barium metaborate crystals induced by femtosecond laser

This paper describes the microstructural transformations of borate glass and barium metaborate crystals induced by femtosecond laser. Such structural transformations were verified by Raman spectroscopy. The borate glass is transformed into low temperature (LT) phase of barium metaborate (BaB_2O_4) crystals after being irradiated for 10 min by a femtosecond laser. In addition, after 20 min of irradiation, high temperature (HT) phase of BaB_2O_4 crystals is also produced. Further studies demonstrate that LT phase BaB_2O_4 crystals are formed in the HT phase BaB_2O_4 crystals after femtosecond laser irradiation for 10 s.