J. Du
,
G.Y.Yang and S. Hagegege(General Research Institute for Non-ferrous Metals
,
Beijing 100088
,
China)(CECM-CNRS
,
15 rue G. Urbain
,
94407 Vitry/Seine
,
France Manuscript received 25 September 1995)
金属学报(英文版)
A model Cu-AlN composite has been prepared by ion implantation technique and annealing. The atomic configuration and lattice relationship of a low-energy inherent interface(11)Cn//(0001)AlN were studied by using transmission electron microscopy and geometrical modelling. By analysing the dichromatic pattern of the composite,a primary structural unit of the interface atomic configuration was determined for purpose of HREM image simulations and of studying the structurul relaxation state in the near-interface region.
关键词:
: Cu-AlN
,
null
,
null
,
null
郦建立
,
李晓明
,
谢根栓
,
姚治铭
,
李劲
,
柯伟
,
抚顺石油学院
材料研究学报
研究了氢蚀温度对20G和15CrMo钢常规力学性能与疲劳性能和机制的影响以及应力比对氢蚀后20G钢疲劳性能的影响结果表明,氢蚀后20G钢的疲劳行为受氢蚀对材料损伤程度和氢蚀导致粗糙的裂纹途径造成闭合效应增加两因素联合作用;氢蚀后15CrMo钢脱碳严重,其疲劳行为仅受脱碳对材料损伤作用的影响;应力比对20G疲劳性能也有很大影响
关键词:
氢蚀
,
null
,
null
,
null
KAVEHArzani
,
BEHDADGhaderiAshtiani
,
AMIRHOSSEINHajiAboutorabKashi
无机材料学报
doi:10.3724/SP.J.1077.2012.12050
Mesoporous carbon CMK-3 was synthesized by using SBA-15 silica mesoporous as hard template and characterized through nitrogen adsorption/desorption and low angle X-ray diffraction. As-prepared material with large pores and high surface area was used to remove Orange G dye from aqueous solution. Adsorption experiments were carried out as batch studies at variety of contact times, pH, initial dye concentrations, temperatures and salt concentrations. Langmuir and Freundlich isotherm models were employed to simulate the equilibrium data of anionic dye. It was found that the equilibrium data were well represented by the Langmuir isotherm, yielding maximum monolayer adsorption capacity of 189 mg/g. Experimental data were analyzed using pseudo-first order and pseudo-second order kinetic models and obtained results indicated that kinetics followed a pseudo-second order equation.
关键词:
CMK-3; Orange G; adsorption isotherm; kinetic
皇艳蕾
,
陈杨英
,
刘秀梅
,
周丹红
,
范荫恒
催化学报
在酸性条件下用正硅酸乙酯(TEOS)和苯基三乙氧基硅(PTES)直接缩合制备了苯基改性的中孔分子筛Ph-SBA-15,并用紫外光谱、红外光谱、X射线衍射、透射电镜和核磁共振等对改性后的样品进行了表征. 结果表明,在300 ℃下焙烧后,模板剂被脱除,而苯基可完整保留,苯基改性的SBA-15分子筛具有有序结构. 进一步用氯磺酸磺化改性后,可得到苯磺酸化的分子筛,其酸度可达4.19 mmol/g.
关键词:
中孔分子筛
,
SBA-15
,
苯改性
,
磺化
陈敏
,
黄豹
,
金红晓
,
金顶峰
,
葛洪良
,
王新庆
复合材料学报
利用浸渍法合成了Co3O4/SBA-15和CoFe2O4/SBA-15介孔纳米磁性材料,并利用X射线粉末衍射(XRD)、透射电子显微镜(TEM)、场发射扫描电子显微镜(FESEM)及振动样品磁强计(VSM)对样品的微观结构和磁性能进行了分析.结果显示,Co3O4及CoFe2O4纳米颗粒分布在SBA-15介孔材料的孔道中,可有效提高SBA-15介孔材料的磁性能.研究发现,SBA-15介孔纳米磁性材料的磁特性由掺杂的纳米磁性颗粒的性质决定,其磁性能随Co3O4及CoFe2O4含量的增加而升高,矫顽力可达400Oe,饱和磁化强度达9 emu/g.
关键词:
SBA-15
,
纳米颗粒
,
复合材料
,
介孔材料
,
微观结构
,
磁学性能
丁志杰
,
郭雨
,
唐婧
,
张婷
,
郭腾
,
陈君华
硅酸盐通报
以3-氨丙基三甲氧基硅烷(APTMS)为功能化试剂,采用水热一步合成法制备出氨基功能化材料NH2-SBA-15.通过X射线衍射、扫描电镜、透射电镜、Fourier红外光谱、N2吸附-脱附和X射线能谱(EDS)对NH2-SBA-15的介孔结构、氨基的负载进行了表征.结果表明,与板状SBA-15相比,氨基功能化样品NH2-SBA-15同样具有板状形貌和二维六方的短孔道介孔结构;随着APTMS量的增加,样品中嵌入的氨基物种增多,样品的短程有序性变差,比表面积降低,孔径减小,部分孔道口发生堵塞.对阴离子染料刚果红的吸附实验表明,氨基功能化后试样的吸附能力增强,其中,APTMS/正硅酸乙酯(TEOS)摩尔比为0.2的试样吸附效果最好,50 mg试样室温下吸附100 mL的0.30mmol/L的刚果红溶液,6min后达到吸附平衡,吸附率为97.5％;试样对刚果红的饱和吸附量可达0.60 mmol/g.
关键词:
介孔SBA-15
,
3-氨丙基三甲氧基硅烷
,
水热法
,
吸附率
,
刚果红
International Journal of Modern Physics B
The perturbation formulae of EPR parameters g factors g(x), g(y) and g(z) for the lowest Kramers doublet of 4f(1) ion in orthorhombic symmetry are established. In these formulae, the contributions of the covalency effects, the admixture between J = 7/2 and J = 5/2 states as well as the second-order perturbation (which is not considered in the previous works) via crystal-field and orbital angular momentum interactions are all included. According to these formulae, and by using the superposition model, the g-factors g., g(y) and g(z) for Ce3+ center in YBa2CU3O6+x superconductor are calculated. The results are discussed.
关键词:
YBa2Cu3O6+x;EPR;superposition model;Ce3+;crystal-field
孔祥涛
,
周志平
,
盛维琛
,
朱申敏
,
张际亮
功能材料
通过浸渍吸附的方法将pH值敏感的功能单体-丙烯酸引入到介孔二氧化硅SBA-15的孔道内,经自由基聚合使丙烯酸(AA)在孔道内聚合,成功合成了pH值敏感的SBA-15/聚丙烯酸(PAA)纳米复合材料,所得纳米复合材料的结构通过XRD、TEM、氮气吸附/脱附、TG、FT-IR等手段进行了表征,并进行了pH敏感性能研究.结果表明,当聚合物(PAA)的量达到20%左右时,复合材料仍然具有较大的孔体积0.5203cm3/g和较高的比表面积334.5m2/g.聚合反应的发生没有破坏SBA-15的有序介孔结构,这种纳米复合材料初步显示出了pH敏感性.这种具有高比表面的pH值响应介孔纳米复合材料,有望在药物缓释领域得到应用.
关键词:
介孔氧化硅SBA-15
,
聚丙烯酸
,
纳米复合物
,
制备
,
性能
Optical Materials
The perturbation formulas of the EPR g factors g,, g and g. for a 4f(11) 1 ion in orthorhombic symmetry are established. In these formulas, the contributions to the g factors arising from the second-order perturbation terms and the admixture of various states are taken into account. The above formulas are applied to the orthorhombic Er3+ centers in YAG, YGG and LuGG garnets. By analyzing their g factors, we find that the polar angles theta(j)(') of the impurity-ligand bonds related to the Z axis of the crystals in these Er3+ centers are smaller than the host angles theta(j) in pure crystals, whereas the azimuthal angles, related to the X axis in the impurity centers are larger than the corresponding phi(j) in the hosts. The g factors and their anisotropies Delta g [= g(z) - (g(x) + g(y))/2] and delta g (= g(x) - g(y)) for Er3+ in the garnets based on the above local structural parameters are in good agreement with the observed values. In addition, the angular distortions Delta theta (= theta(j)(') - theta(j)) or Delta phi (= phi(j)(') - phi(j)) obtained by analyzing the EPR data in this work are different from Delta theta(2), or Delta phi(2) (for only the second set of ligands, i.e., j = 2) based on the superposition model crystal-field analysis in the previous work. The validity of the results is discussed. (c) 2004 Elsevier B.V. All rights reserved.
关键词:
electron paramagnetic resonance (EPR);defect structure;crystal-field;and spin hamiltonians;Er3+;garnets
