双作用变量叶片泵自动控制系统的机理分析

文章介绍了一种双作用变量叶片泵自动控制系统,通过电脑控制变频器,改变叶片泵转速,达到粗调目的;电脑控制电液数字阀,起微调作用.蓄能器的利用,进一步增了系统的稳定性.     

双包络TI-环面蜗杆传动的二次包络分析

在一次包络分析的基础上,着重进行了二次包络齿面接触分析,推导出了蜗杆和蜗轮齿面方程。齿面接触分析表明：齿面呈双线接触,润滑条件好,承载能力大,在重型机械传动装置中具有实用价值。     

Partial Oxidation of Methane to Syngas over Calcined Ni–Mg/Al Layered Double Hydroxides

The catalytic partial oxidation of CH₄ to syngas was carried out over an Ni–Mg/Al mixed-oxide catalyst prepared from layered double hydroxide-type precursors. The catalysts were characterized by XRD, TPR, UV-DRS, XRF, BET and CHNS analysis. The effects of the catalyst composition and the calcination temperature on the catalytic performance and the extent of catalyst deactivation were investigated. Ni–Mg/Al oxide catalysts converted CH₄ into syngas efficiently with high selectivity. The catalyst performance was strongly related to the Ni particle size and the calcination temperature. The catalysts that were calcined at higher temperature exhibited a better catalytic performance. In conclusion, the NiAl₂O₄ spinel phase had a positive effect on the stability of the catalyst.     

DEDS-10双子表面活性剂的性能研究

合成了一种新型的DEDS-10双子表面活性剂,用红外光谱对所合成化合物的结构进行了初步表征。DEDS-10的临界胶束浓度cm c为0.47 mmol/L,γcm c为34.5 mN/m,A lC l3、CaC l2和NaC l可以使γcm c降低3.6~1.1 mN/m,其cm c值大约为纯水溶液cm c值的1/5~1/3;加入乙醇,可增加其表面活性,在乙醇的浓度为0.22 mol/L时,其表面张力为30 mN/m左右。与阳离子表面活性剂DTAB和非离子表面活性剂曲拉通X-100复配,可以大幅度地降低cm c和γcm c值,与阴离子表面活性剂TLS复配时,cm c降低,cγm c略有增加。     

表面有机化钛酸材料的制备及吸附染料性能

将K2CO3和TiO2通过高温固相反应制得K2Ti4O9,经酸化处理后得到H2Ti4O9,用正十二胺乙醇溶液与之反应,获得正十二胺柱撑的层状化合物,采用X射线衍射(XRD)、红外光谱(IR)等方法对所得材料进行结构表征,并初步研究了有机胺支撑前后钛酸材料的吸附性能,实验结果表明:在钛酸钾材料的层间引入正十二胺有机基团后,层间距加大,吸附能力大大提高。     

纳米层状双金属氢氧化物的制备及结构表征

采用恒定pH 12±0.2,按n(Mg2+)∶n(Al3+)∶n(OH-)∶n(CO2-3)=6∶2∶16∶1配制溶液,采用一步反应液相法,制备纳米层状双金属氢氧化物(LDH)粉体.为了获得无团聚、分散均匀的纳米粉体,探讨了溶剂置换干燥、真空干燥、常压干燥对纳米LDH粉体形成团聚的影响;用X射线衍射仪、透射电镜、红外光谱仪和元素分析仪对样品的物相、形貌、粒径和组成进行了表征.结果表明,溶剂置换干燥能够有效防止纳米粉体形成硬团聚,样品分散性好,呈针状形态,长50 nm,宽5 nm.     

有机硅对无机层状材料的插层处理

主要介绍了无机层状材料的结构、插层的方法、插层产物的表征等。     

复分解四步循环法制取硫酸钾新工艺

介绍了制取硫酸钾的一种新工艺－－复分解四步循环法，即氯化钾与硫酸铵反应生成硫酸钾铵与氯化铵钾，硫酸钾铵再与氯化钾溶液反应生成硫酸钾，氯化铵钾再与硫酸铵溶液反应生成氯化铵。整个工艺全封闭循环生产，产品硫酸钾K2O质量分数≥50％，钾收率达92％。     

剪切速率和静置时间对Fe-Al-Mg-MMH/钠质蒙脱土复合触变性体系触变性的影响

研究了测定条件对R=0.051的Fe-Al-Mg型混合金属氢氧化物(简称MMH)/钠质蒙脱土(简称MT)复合触变性悬浮体性质的影响.主要考察了高速剪切分散后,测定粘度(η)随时间(t)变化时采用的剪切速率(DL)和测定η前的静置时间(ts)的影响发现DL和ts的影响很复杂,ts=0,低DL时(10和170s-1)呈现复合触变性的体系,在高DL时(340、511和1022s-1)可呈现正触变性;DL增加,体系η逐渐降低.在所研究的ts范围内(0～2h),随ts的增加,体系分别由低DL时(10和170s-1)的复合触变性和高DL时(340、511和1022s-1)的正触变性皆转变为负触变性.低DL时(10和170s-1),η随ts逐渐降低;高DL时(340、511和1022s-1),η随t逐渐增高.对影响机理进行了初步探讨.     

Electrical double layer characteristics of nanoporous carbon derived from titanium carbide

Electrochemical parameters of the nanoporous carbide-derived carbon|organic electrolyte have been studied by cyclic voltammetry and electrochemical impedance spectroscopy. The gas adsorption measurements have been used for evaluating the specific surface area, pore size distribution and porosity as the essential parameters influencing the double layer performance of carbon. The region of ideal polarizability, values of series and parallel resistance, capacitance and other important electrical double layer parameters were established. It was shown that specific capacitance of typical nanoporous carbon derived from titanium carbide is in the range of 70-90 F cm⁻³ or 100-130 F g⁻¹ and it depends on the synthesis conditions. The influence of the electrolyte solvent to the capacitance was insignificant, although acetonitrile was advantageous with respect of smaller viscosity.