Synthesis, characterization and reaction behaviour of lamellar AFm phases with aliphatic sulfonate-anions

The addition of alkanesulfonates as admixtures to cementitious materials allows the formation of new lamellar phases (AFm), which was proofed by X-ray diffraction (XRD). The course of hydration was investigated by heat flow calorimetry.The layered structures of AFm phases are composed of brucite-like main layers and interlayers containing alkanesulfonate ions and additional H₂O molecules. These structural not necessary H₂O molecules release gradually at definite steps with increasing temperature. With varying relative humidity the layer thickness c′ of short aliphatic chained calcium aluminate alkanesulfonate hydrates changes considerably, whereas large organic molecules dominate the layer thickness of those with longer aliphatic chains. By means of the increase of layer thickness with increasing chain lengths it is possible to determine the tilt angles of the aliphatic chains in the interlayers.     

蒙脱石的电子自旋共振研究

对蒙脱石及其改型处理的样品作了电子自旋共振(ESR)研究。结果表明,在蒙脱石的 ESR 谱中有两个主要的特征信号,其 g 值分别为 g_((?)ff)～4.3和2.0。前者对应蒙脱石中 Fe~(3+)离子的强结构信号,后者描述了蒙脱石层间离子相关的信号,它随着不同离子的交换改型而敏感地变化。在样品加热处理后,两者的信号发生了大的变化。这种变化反映了蒙脱石层间离子的构形形态的变化、迁移以及蒙脱石层结构的变化。     

Synthesis and characterizations of a polyimide containing a triphenylamine derivative as an interlayer in polymer light-emitting diode

Polyimide containing triphenylamine derivative (TPD-PI) was synthesized to prepare a polymer interlayer having insolubility in common nonpolar solvent for light-emitting polymers. N,N′-diphenyl-N,N′-bis(4-aminophenyl)-1,1-biphenyl-4,4′-diamine, as a new triphenylamine-containing diamine monomer, was synthesized by the palladium-catalyzed amination reaction between 4-nitrodiphenylamine and 4,4′-dibromobiphenyl and subsequent reduction of the nitro-intermediate. The TPD-PI was prepared from the synthesized diamine monomer and 4,4′-(hexafluoropropylidene)-diphthalic anhydride by the standard two-step polymerization method, which involved ring-opening polymerization and subsequent cyclodehydration. The structures and properties of the monomer and the resulting polyimide were characterized with ¹H and ¹³C NMR, elemental analysis, gel permeation chromatography, UV-visible spectroscopy, etc. The TPD-PI is readily soluble in aprotic polar solvents such as N-methyl-2-pyrrolidinone and N,N-dimethylformamide and insoluble in nonpolar solvents such as toluene and xylene. The highest occupied molecular orbital (HOMO) level of the TPD-PI was measured to be 5.5 eV by a photoelectron spectrometer in air, and the band gap was calculated as 3.1 eV from the onset of UV-vis spectrum. The polymer light-emitting diode with the thin TPD-PI layer between a hole injection layer and an emitting polymer layer was fabricated to examine the performance of the polyimide as an polymer interlayer. Although the luminous efficiency of the device is lowered by the introduction of the TPD-PI interlayer, the lifetime of the device is improved.     

依坡就势,兼容并蓄——邵阳学院体育教学中心设计理念

高校体育建筑兼有文化性和时代性,它既要强调文化传统和校园文脉,又要体现体育建筑的时代特色。建筑设计应注重简洁、朴实和高品格,而不在于材料、装修的豪华及过分做作的造型。本案设计将定位于突出高校体育建筑特殊性以区别公共体育建筑,体现其实用性、兼容性与高效性,同时应节约土地和成本,充分利用建筑空间,营造宜人的校园氛围。     

Boron nitride substrate-induced reversible hydrogen storage in bilayer solid matrix via interlayer spacing

By using first-principles methods, we perform a theoretical investigation of adsorption of hydrogen molecules between bilayer solid matrix layers (bilayer boron nitride sheets (BBN) and graphene/boron nitride heterobilayers (GBN)) with variable interlayer distance (ILD). We find that the H₂ adsorption energy has a minimum by expanding the interlayer spacing, along with further interlayer expansion, arising from many H₂ binding states and electrostatic interaction induced by the polar nature of B–N bonds. To determine if successive addition of H₂ molecules is indeed possible using the minimal H₂ adsorption energy as the reference state, we then simulate the hydrogen storage capacity of BBN and GBN with different stacking types, and find that the GBN with Bernal stacking is superior for reversible hydrogen storage. Up to eight H₂ molecules can be adsorbed with the average adsorption energy of −0.20 eV/H₂, corresponding to ∼7.69 wt % hydrogen uptake.     

涩北一号气田隔层特征及对气田出水影响研究

涩北一号气田作为第四系疏松砂岩气田,由于特殊的沉积环境形成了纵向上砂泥频繁交互的分布特点,气田泥质隔夹层广泛分布,并具有一定的厚度和渗透性。通过对涩北气田隔层岩性、分布及渗透率特征分析研究,认为气田泥岩隔层较发育,具有一定的水蕴藏量,结合气田出水现状,认为隔层水窜是目前气田气井出水的主要原因之一。     

同井注采井区隔层窜流界限研究

井下油水分离技术可使产出液在地下实现油水分离,达到减少地面水处理量,提高驱油效率的目的。但实施此项技术之后,同井注采井区回注层与产出层之间的压差增大,当二者之间压差大于隔层启动压力梯度时, 隔层流体发生窜流。为防止隔层流体发生窜流,根据A油田实际地层参数,建立同井注采模型,研究实施同井注采技术之后隔层发生窜流的范围及单井日产液量的上限值,得到隔层渗透率-厚度-单井日产液量界限图版。分析图版可知,当前A油田同井注采井单井日产液量为70m³ 条件下,隔层渗透率为1×10-10^-3μm²时,隔层厚度下限值为2.3 m;隔层厚度为3m 时,隔层渗透率上限值为1.25×10^-3μm²。在隔层物性参数变化时,可根据图版确定同井注采井合理的单井日产液量,对油田开发方案的制定具有一定的指导意义。     

Fatigue behaviour of Al/steel dissimilar resistance spot welds fabricated using Al–Mg interlayer

Aluminium alloy sheets were joined to stainless steel ones by a resistance spot welding method using Al–Mg alloy interlayer. The interlayer exhibits a lower melting point than the Al alloy. Consequently, melted interlayer with a lower temperature filled the gap between the two sheets and resulted in effective joining. Subsequently, tensile shear fatigue tests had been conducted to evaluate fatigue strength and to determine the fatigue fracture mechanism. Resistance spot welding dissimilar welds exhibited higher fatigue strengths than friction stir spot welded dissimilar ones. Fatigue fracture modes were dependent on the load levels, where plug type fracture occurred at high load levels, shear fracture through the nugget at medium load levels and through thickness fatigue crack propagation in the Al sheet at low load levels. The fracture mode transition was attributed to the geometrical rotation around the nugget.     

铝锂合金无中间层扩散焊接工艺研究

概述了铝锂合金超塑成形 /扩散焊接技术的现状 ,研究了铝锂合金无中间层扩散焊接工艺 ,通过选取适当的工艺参数和焊接前化学处理 ,使焊件获得较高的剪切强度。     

通过过渡层改善金刚石膜和基底间的结合性能

介绍了在金刚石膜和基底间通过施加过渡层以改善金刚石膜与基底间的结合性能的研究成果。金刚石膜可以通过过渡层沉积于多种基底上,如Ｓｉ、ＳｉＯ２ 、陶瓷（ＳｉＣ,Ａｌ２Ｏ３） 、钢及硬质合金基底等。过渡层有单层（ 如ＤＬＣ、Ｃ６０ 、Ｙ ＺｒＯ２ 、Ｃ Ｎ 膜、ＴｉＣ或ＴｉＮ） 和多层（ 如Ｍｏ／Ｎｉ、Ｍｏ／ＴｉＮ 或Ｂ／ＴｉＢ２／Ｂ 等） 之分,根据金刚石、过渡层及基底的晶格匹配性和热学匹配性,对于不同的基底应选择不同的过渡层。