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排序方式: 共有2392条查询结果,搜索用时 17 毫秒
991.
992.
对性质不同的润滑油料分别进行了磺化和酸精制试验 ,发现磺化和酸精制的效果与多方面因素有关 ,应根据原料的性质和所需产品的不同 ,选取合适的工艺及条件。在酸精制中可用瓷环式或反应器代替搅拌式反应器。 相似文献
993.
Potential candidates for thin-film diffusion soldering were investigated by analysis of phase formation and measurements of
mechanical and thermal stability of thin-film bonds. Bilayers of Pt/In, Pd/In, and Zr/Sn of 500 nm/500 nm thickness were prepared
by direct current magnetron sputtering followed by a 5 nm, thin protective Au layer. Single bilayer samples were heat-treated
between 200°C and 500°C for 3–30 min and studied by x-ray diffraction (XRD) analysis. Some bilayers were bonded face-to-face
between 300°C and 500°C for 3–30 min and sheared-off either in shear-strength measurements at room temperature or in remelting
experiments up to 1,100°C. Phase formation in Pd/In and Pt/In thin films is much faster than in Zr/Sn thin films. An interaction
of Au in addition to a questionable thermal stability of PtIn2 complicated the reaction in Pt/In samples. A revised partial Pd-In phase diagram was constructed, correcting the compound
‘PdIn3’ to Pd3In7. The Pt/In and Pd/In thin-film systems are very promising candidates for thin-film diffusion soldering. 相似文献
994.
人工神经网络方法预测润滑油基础油的抗氧性 总被引:5,自引:0,他引:5
用反向传播神经网络方法研究了润滑油放置氧弹时间与基础油化学组成之间的关系。研究表明,网络方法比常用的线性或指数关联法更能准确地关联和预报润滑油基础油的抗氧性。本文还对输入参数的选择及过拟合现象的预防方法进行了研究。 相似文献
995.
Sungkwon Jeon Hansoo Kim Juyeon Choi Jeong F. Kim Ho Bum Park Jung-Hyun Lee 《Advanced functional materials》2023,33(22):2300183
Membrane-based separation technologies have attracted significant interest from various industries owing to their high process efficiency. However, the wider applications of conventional polyamide (PA) thin-film composite (TFC) membranes are limited by their poor pH stability and low cation selectivity, necessitating the development of membranes with advanced chemistries. Herein, an extreme pH-resistant, highly cation-selective TFC membrane is fabricated by synthesizing a crosslinked poly(quaternary ammonium) (PQA) selective layer on a polyethylene support via Menshutkin reaction-based interfacial polymerization (Men-IP). The Men-IP process produces a thin, densely crosslinked, and positively charged PQA permselective layer without hydrolysis-prone functional groups. The fabricated PQA membrane features a highly selective molecular density that significantly exceeds those of previously reported membranes with non-PA chemistries. Moreover, the PQA membrane exhibits remarkably high rejection (>90%) and selectivity for divalent cations owing to the exceptionally strong positive charge imparted by its abundant cationic QA groups. More importantly, the PQA membrane displays ultrahigh pH stability under both extremely acidic (1.5 m H2SO4) and alkaline (5 m NaOH) conditions for 28 days. No other membrane reported in the literature demonstrates such excellent pH stability. This strategy opens a new route for fabricating highly selective membranes that can be used in harsh pH environments. 相似文献
996.
George W. Mattson Kyle T. Vogt John F. Wager Matt W. Graham 《Advanced functional materials》2023,33(25):2300742
Under varying growth and device processing conditions, ultrabroadband photoconduction (UBPC) reveals strongly evolving trends in the defect density of states (DoS) for amorphous oxide semiconductor thin-film transistors (TFTs). Spanning the wide bandgap of amorphous InGaZnOx (a-IGZO), UBPC identifies seven oxygen deep donor vacancy peaks that are independently confirmed by energetically matching to photoluminescence emission peaks. The subgap DoS from 15 different types of a-IGZO TFTs all yield similar DoS, except only back-channel etch TFTs can have a deep acceptor peak seen at 2.2 eV below the conduction band mobility edge. This deep acceptor is likely a zinc vacancy, evidenced by trap density which becomes 5-6× larger when TFT wet-etch methods are employed. Certain DoS peaks are strongly enhanced for TFTs with active channel processing damage caused from plasma exposure. While Ar implantation and He plasma processing damage are similar, Ar plasma yields more disorder showing a ≈2 × larger valence-band Urbach energy, and two orders of magnitude increase in the deep oxygen vacancy trap density. Changing the growth conditions of a-IGZO also impacts the DoS, with zinc-rich TFTs showing much poorer electrical performance compared to 1:1:1 molar ratio a-IGZO TFTs owing to the former having a ∼10 × larger oxygen vacancy trap density. Finally, hydrogen is found to behave as a donor in amorphous indium tin gallium zinc oxide TFTs. 相似文献
997.
将异丙醇与糠醛配成双溶剂,分别采用糠醛单溶剂及异丙醇与糠醛的双溶剂对工业废润滑油进行溶剂精制,对回收工艺进行了研究。结果表明:双溶剂精制的效果优于糠醛单溶剂精制的效果。其最佳工艺条件是:精制温度为75℃,异丙醇与糠醛的体积比为1∶1,剂油体积比为1.5∶1。在最佳工艺条件下,所回收油品的粘度指数为119.5,折光率为1.476 6,色度为1.0,凝点为-15.8℃,闪点为218.4℃,硫质量分数为0.026%,油品的总收率为72.5%。 相似文献
998.
为了监测在用合成航空润滑油抗氧剂消耗程度,采用合成基础油定量加绘制标准曲线的方法分析测定了润滑油中抗氧剂浓度.分析了润滑油的红外吸收光谱和抗氧剂仲胺基团的特征吸收峰,选择了3320 cm-1与3420 cm-1两点基线校正峰高建立标准曲线,其相关系数R2=0.9911.该方法的检出限低至0.003 mol/L,定量限为0.009 mol/L.用标准曲线对配制的样品和在用润滑油抗氧剂进行预测,其标准偏差分别为0.0014和0.0023,与理论值和色谱法测定值接近;在用油的加标回收率在87.9%~94.3%之间,准确度较高.研究结果表明,通过建立标准曲线,中红外光谱可用于在用润滑油抗氧剂损耗的监测. 相似文献
999.
为了提高公交车两用燃料发动机油的摩擦性能,将烃分子添加剂加入 CNG/汽油两用燃料机油中,采用四球摩擦磨损试验机和梯姆肯试验机,考察其对 CNG/汽油两用燃料机油摩擦性能的影响,利用 SEM表面分析技术对摩擦副表面进行了磨损机理分析.试验表明:烃分子添加剂对CNG/汽油两用燃料机油摩擦学性能有所提高,对摩擦副表面具有修复平整作用 相似文献
1000.
In the present study,anodic films on aluminium alloy was used as the dielectric layer for Cu thinfilm temperature sensor,and then Cu film was deposited by unbalanced magnetron sputtering ion plating as the sensitive layer.Microstructure and surface morphologies of Cu film were investigated by optical microscope(OM),atomic force microscope(AFM) and scanning electron microscope(SEM).Electrical properties of Cu thin-film temperature sensor were tested by four-point probe technique and Digit Multimeter.The results showed that the surface roughness of anodic films can be reduced from Ra 58.096 nm to Ra 16.335 nm by proper polishing.Continual Cu stripes can be obtained both on polished anodic alumina film and smooth alumina wafer by etching after Cu film annealing.The resistivity of Cu films before and after 300 ℃ as well as 400 ℃ annealing are 12.48 mΩ·cm,5.48 mΩ·cm and 4.83 mΩ·cm,respectively.The resistances of Cu thin-film temperature sensor in 70 ℃ and 0 ℃ are 946.5 Ω and 761.15 Ω respectively.The temperature coefficient of resistivity(TCR) of the sensor is 3479 × 10- 6 /℃. 相似文献