原子荧光法测定催化裂化装置平衡剂中的锑

通过对不同测定条件的研究,确定了原子荧光法用于测定催化裂化装置平衡剂中的锑含量。考察了平衡剂样品的预处理方法以及各种因素对测定结果的影响。结果表明,原子荧光法操作简单,测量速率快,分析结果的精密度和准确度高,能够满足平衡剂中锑含量分析的需要,为催化裂化装置的生产调节提供有利的依据。     

十溴二苯乙烷协同三氧化二锑阻燃聚对苯二甲酸丁二醇酯

以十溴二苯乙烷(DBDPE)和三氧化二锑(Sb2O3)作为复合阻燃剂，对聚对苯二甲酸丁二醇酯(PBT)进行改性。研究了复合阻燃剂对PBT的燃烧性能、热稳定性能和力学性能的影响，并其对阻燃机理进行了探讨。结果表明，阻燃剂DBDPE／Sb2O3对PBT具有良好的阻燃效果，热稳定性能基本不变，而其拉伸强度、冲击强度和弯曲强度都随阻燃剂用量的增加先增后降，阻燃剂的用量不宜过大。     

DPDBO/Sb2O3/DMDPB在LDPE阻燃处理中的应用

研究了2,3-二甲基-2,3-苯基丁烷(DMDPB)、三氧化二锑(Sb2O3)和十溴二苯醚(DBDPO)的加入对低密度聚乙烯(LDPE)的拉伸和阻燃性能的影响探讨了DBDPO与Sb2O3加入量的不同给LDPE的拉伸强度、断裂伸长率和阻燃性能带来的差异。同时研究表明少量的DMDPB加入LDPE／Sb2O3／DBDPO体系,即可显著提高断裂伸长率和阻燃性能。     

纳米SnO_2:Sb导电薄膜制备及导电网络形成机理

在三乙醇胺作用下利用SnCl4和SbCl3共沉淀合成了SnO2:Sb纳米粒子,通过球磨分散得到了纳米SnO2:Sb网络结构的悬浮体系,该悬浮体系形成的玻璃质导电薄膜表面电阻达到107Ω。三乙醇胺提高了SnO2:Sb前驱体胶粒间静电斥力,增大了胶粒分散程度,促进了SnO2:Sb立体网络结构的形成。采用TEM、Zeta电位和XPS分析方法,研究了三乙醇胺与SnO2:Sb前驱体颗粒的相互作用,解释了SnO2:Sb导电网络的形成过程。     

不同成分Al-Mg3Sb2复相涂层的组织和性能

目的研究Mg_3Sb_2含量对Al-Mg_3Sb_2复相涂层组织、耐蚀性和硬度的影响,对比纯Al涂层和添加不同含量Mg_3Sb_2涂层性能的差异。方法采用氧乙炔火焰喷涂技术和自制的Mg_3Sb_2粉末,在AZ31B镁合金表面制备不同成分的Al-Mg_3Sb_2复相涂层。采用扫描电镜(SEM)观察了涂层的微观组织,利用X射线衍射仪(XRD)分析了球磨粉末和涂层的物相组成,通过电化学工作站(CHI660e)对试样在3.5%Na Cl溶液中进行电化学腐蚀性能测试,并用显微硬度计测试了涂层的硬度。结果经火焰喷涂之后,获得了不同成分的Al-Mg_3Sb_2复相涂层,涂层中的物相主要为Al和Mg_3Sb_2。当Mg_3Sb_2的质量分数为40%和60%时,涂层组织致密,气孔、裂纹等组织缺陷较少。Tafel极化曲线测试中,随着第二相Mg_3Sb_2质量分数的增加,涂层的腐蚀电位逐渐正移。当质量分数达到80%时,其腐蚀电位为-0.9819 V,比纯Al涂层正移417.3 m V,腐蚀电流密度为0.048×10-3 A/cm2,约是纯Al涂层的1/2。显微硬度结果显示随着Mg_3Sb_2含量的增加,涂层的硬度逐渐提高,当质量分数达到80%时,涂层的平均硬度达到334.2HV,是纯Al涂层的6.79倍。结论Mg_3Sb_2的加入可以获得组织较好的涂层,随着其含量的增加,涂层的耐蚀性和显微硬度逐渐提高。     

Sb对AM50-Y镁合金组织和力学性能的影响

研究合金元素Sb对AM50-Y合金显微组织和力学性能的影响。结果表明,加入Sb后,合金晶粒明显细化,同时形成弥散分布的YSb相。YSb相作为异质形核核心,促进了细小弥散分布的Al2Y颗粒相的形成。随着Sb含量的增加,合金室温和150℃高温抗拉强度、延伸率及室温冲击韧性先上升后下降。当Sb含量为0.6%时,合金综合力学性能最好:合金室温抗拉强度、延伸率和冲击韧性分别为257MPa、9.9%和26J·cm-2,与未添加Sb合金相比分别提高了13.7%、15.9%和14.9%;合金的高温抗拉强度和延伸率达到203MPa和11.9%,分别提高了12.8%和15.5%。     

rGO-Sb2Se3薄膜电化学共沉积制备及光电化学性能

采用恒电位沉积法,在二元Sb-GO溶液体系中得到rGO-Sb预制层,在此过程中,GO被有效还原成rGO,并与Sb形成化学键。随后通过将预制层进行二段硒化热处理,快速去除多余的Se制备出rGO-Sb₂Se₃光阴极薄膜。通过XRD、SEM、Raman、XPS、UV-vis及PEC等手段对薄膜样品进行表征以及光电化学性能测试。结果表明:负载rGO使得rGO-Sb₂Se₃在700 nm以内的可见光区域的光吸收系数显著提升。rGO优良的导电性能及较高的载流子迁移率,可以快速转移电荷,抑制载流子的复合,因此光电化学性能以及光稳定性大大提高,光电流密度增大至接近Sb₂Se₃单相的2倍(?0.20 mA/cm²)。又因为rGO-Sb₂Se₃导带位置(?0.74 V vs.RHE)远负于析氢电位(0 V vs.RHE),故可作为一种新型光还原产氢的阴极,具备广阔的应用前景。     

First principles calculations of the electronic, dynamical, and thermodynamic properties of the rocksalt ScX (X = N, P, As, Sb)

We have investigated the electronic, dynamical, and thermodynamic properties of the rocksalt ScX (X = N, P, As, Sb) using a plane-wave pseudopotential method within the generalized gradient approximation in the frame of density functional perturbation theory. The calculated lattice constants are found to differ by less than 0.56% from the available experimental values. These materials have the indirect Γ–X band gaps and a wide and direct band gap at the X-point in band structure, which are closer to experimental results than the previous calculations. A linear-response approach is used to calculate the phonon frequencies, the phonon density of states and LO–TO splitting. The obtained phonon frequencies at the zone-center (Γ-point) for the Raman-active and infrared-active modes are analyzed. We also calculate the thermodynamic functions using the phonon density of states, and the calculated values are in nearly perfect agreement with experimental data.     

Effect of phosphoric acid on the performance of low antimony grid of Pb‐acid cell under constant current charging and discharging

Effect of phosphoric acid on the performance of Pb‐1.7%Sb grid of lead‐acid cell is studied in 5 M H₂SO₄ by cyclic galvanostatic polarization and impedance spectroscopy. An increase in capacitance to a maximum is recorded during the initial stages of the electro‐reduction of PbO₂ into Pb(II) compounds and attributed to concurrent compositional and dimensional changes. These changes include removal of O₂ bubbles, insertion of large amounts of H₂SO₄ and H₂O. Efficiency of PbO₂ formation decreases, while its rate of self‐discharge increases with increasing the charging current and in the presence of H₃PO₄. The charge capacity increases with increasing the discharging current due to the decrease in the self‐discharge. The charge capacity is lower in the presence of H₃PO₄. On increasing the cycle number, the corrodibility of the grid increases, because more layers of the surface Pb are involved in the self‐discharge. H₃PO₄ significantly retards the effect of cycle number.     

Lowering of Sn−Sb alloy melting points caused by substrate dissolution

Sn−5wt.%Sb alloy is used for the soldering of ceramic devices. Reaction couples, dissolution, and differential scanning calorimetry experiments are conducted to examine the interfacial reactions and dissolution of Ag substrates with the molten Sn−5wt.%Sb solder. One intermetallic compound, Ag₃Sn, is formed at 260°C at the Sn−5wt.%Sb/Ag contact. With the intake of Ag from the substrate, the binary Sn−5wt.%Sb alloy becomes a ternary (Sn−5wt.%Sb)_100−xAg_x melt. It is found that a small amount of Ag addition significantly lowers the melting point of the Sn−5wt.%Sb alloy. This phenomenon is illustrated with the (Sn−5wt.%Sb)_100−xAg_x isoplethal section.