SiC晶须增韧Al2O3及ZrO2（Y2O3）基陶瓷复合材料的抗热震行为

采用三点弯曲及扫描电镜等方法研究了ＳｉＣｗ／Ａｌ２Ｏ３，ＳｉＣｗ／ＺｒＯ２）及ＳｉＣｗ／Ａｌ２Ｏ３＋ＺｒＯ２（Ｙ２Ｏ３）陶瓷复合材料的抗热震性。结果表明ＳｉＣｗ的加入使Ａｌ２Ｏ３，ＺｒＯ２（Ｙ２Ｏ３）以及Ａｌ２Ｏ３＋ＺｒＯ２（Ｙ２Ｏ３）基体的抗热震性显著提高，Ａｌ２Ｏ３陶瓷基复合材料的抗热震性明显优于ＺｒＯ２（Ｙ２Ｏ３）陶瓷基复合材料。同时发现在Ａｌ２Ｏ３＋ＳｉＣｗ材料基础上再加入少量ＺｒＯ２９２     

SiC晶须增韧Al_2O_3及ZrO_2（Y_2O_3）基陶瓷复合材料的抗热震行

采用三点弯曲及扫描电镜等方法研究了ＳｉＣｗ／Ａｌ２Ｏ３、ＳｉＣｗ／ＺｒＯ３（Ｙ２Ｏ３）及ＳｉＣｗ／Ａｌ２Ｏ３＋ＺｒＯ２（Ｙ２Ｏ３）陶瓷复合材料的抗热震性．结果表现ＳｉＣｗ的加入使Ａｌ２Ｏ３、ＺｒＯ２（Ｙ２Ｏ３）以及Ａｌ２Ｏ３＋ＺｒＯ２（Ｙ２Ｏ３）基体的抗热震性显著提高，Ａｌ２Ｏ３陶瓷基复合材料的抗热震性明显优于ＺｒＯ２（Ｙ２Ｏ３）陶瓷基复复合材料．同时发现在Ａｌ２Ｏ３十ＳｉＣｗ材料基础上再加入少量ＺｒＯ２（２Ｙ）颗粒（１０Ｖｏ１％），也可进一步提高Ａｌ２Ｏ３＋ＳｉＣｗ材料的抗热震性．     

CaO－SiO＿2－CaSO＿4－CaF＿2－Al＿2O＿3系统中3C＿2S·3CaSO＿4·CaF＿2的形成动力学

３Ｃ＿２Ｓ·３ＣａＳＯ＿４·ＣａＦ＿２是水泥熟料烧成中应用ＣａＳＯ＿４和ＣａＦ＿２作为复合矿化剂时重要的中间化合物。探讨了Ａｌ＿２Ｏ＿３存在时３Ｃ＿２Ｓ·３ＣａＳＯ＿４·ＣａＦ＿２的形成动力学。研究发现Ａｌ＿２Ｏ＿３的存在促进了３Ｃ＿２Ｓ·３ＣａＳＯ＿４·ＣａＦ＿２的形成反应，降低了固相反应活化能，提高了控制反应过程组分ＣａＯ的扩散速率。     

Si＿3N＿4－Al＿2O＿3－ZrO＿2系陶瓷表面氧化层组成的EPMA分析

利用ＥＰＭＡ和ＸＲＤ的分析方法，研究了Ｓｉ＿３Ｎ＿４－Ａｌ＿２Ｏ＿３－ＺｒＯ＿２系陶瓷材料表面氧化层组成。结果表明，Ｓｉ＿３Ｎ＿４－Ａｌ＿２Ｏ＿３－ＺｒＯ＿２系陶瓷材料表面氧化层是由方石英相、ＺｒＳｉＯ＿４相和含有Ａｌ＿２Ｏ＿３、ＣａＯ等的ＳｉＯ＿２玻璃相所组成，其中ＳｉＯ＿２玻璃相中Ａｌ＿２Ｏ＿３、ＣａＯ等的含量，随着氧化时间的增加而逐渐增加。     

反应自生Al_3Ni－Al_2O_3－Al复合材料

通过热力学计算，选择Ｎｉ_２Ｏ_３粉末作原材料，采用反应挤压铸造方法实现了Ａｌ与Ｎｉ２Ｏ３直接压铸反应合成Ａｌ３Ｎｉ－Ａｌ２Ｏ３－Ａｌ原位复合材料。研究了压铸工艺参数和预制块中纯Ａｌ粉的含量对反应合成复合材料过程的影响，并对反应机理做了较深入的分析。结果表明，Ｎｉ２Ｏ３与Ａｌ的反应是为高放热反应，反应是爆发式的，通过调整预制块中Ａｌ粉的体积分数控制了反应的剧烈程度，并能获得不同组成和基体含量的复合材料。对反应机理的分析表明，在Ａｌ足量的情况下，Ｎｉ２Ｏ３与Ａｌ反应合成复合材料分为两个过程，一是反应过程，即Ｎｉ２Ｏ３＋Ａｌ→Ａｌ２Ｏ３＋［Ｎｉ］；二是凝固过程，即反应后多余的Ａｌ与反应生成的［Ｎｉ］在随后冷却中的凝固过程，最终形成Ａｌ３Ｎｉ＋α－Ａｌ２Ｏ３＋Ａｌ复合材料。     

Al2O3-Na2O-CaO-SrO系统富Al2O3区域固态反应的研究

用理学Ｘ射线衍射仪、ＴＧ－ＤＴＡ、ＩＲ－４４０ 红外光谱研究了Ａｌ２Ｏ３－Ｎａ２ Ｏ－ＣａＯ－ＳｒＯ系统富Ａｌ２Ｏ３ 区域固态反应。实验结果表明,煅烧过程固态反应的最终物相组成为Ｎａ２Ｏ·１１Ａｌ２Ｏ３,ＣａＯ·６Ａｌ２Ｏ３ ,ＳｒＯ·６Ａｌ２Ｏ３ 与α－Ａｌ２Ｏ３ 共存     

Si3N4陶瓷材料高温氧化层的分析

利用ＸＲＤ，ＥＰＭＡ，ＸＰＳ和ＳＥＭ的分析方法，研究了在１３００℃下氧化后Ｓｉ３Ｎ４陶瓷材料表面氧化层的组成的形貌，结果表明，Ｓｉ３Ｎ４陶瓷材料的表面氧化层是由方石英相和含有Ａｌ２Ｏ３，ＣａＯ等杂质的ＳｉＯ２质玻璃相所组成，其中ＳｉＯ２玻璃相听Ａｌ２Ｏ３，ＣａＯ等杂质的含量随氧化时间的增加而逐渐增加，同时在氧化层的内部都还存在部分Ｓｉ２Ｎ２Ｏ相。     

AST液相添加剂对PTCR陶瓷电性能的影响

研究了液相添加剂ＡＳＴ（Ａｌ２Ｏ３＋ＳｉＯ２＋ＴｉＯ２）对ＢａＴｉＯ３陶瓷材料电性能的影响，随着Ａｌ２Ｏ３含量的增加，材料的电性能降低，ＳｉＯ２、ＴｉＯ２的物理特性对材料电性能影响较大，过量ＴｉＯ２对材料ＰＴＣ效应有重要影响。     

灰关联法分析三元复合驱体系对A3钢腐蚀的主要影响因素

采用灰关联分析法找三元复合驱（氢氧化钠－石油磺酸钠－部分水解聚丙烯酰胺）体系中的所有要素在可能存在的浓度范围内导致Ａ３钢发生电化学腐蚀的顺序。在含氢龙钠的溶液中,ＮａＯＨ对Ａ３钢腐蚀的影响最大,其次是ＨＣＯ３和Ｃａ＾２＋,再其次是部分水解聚丙酰胺（ＨＰＡＭ）和Ｃｌ＾－,影响最小的是石油磺酸钠（ＲＳ）。在不含ＮａＯＨ的溶液中,Ｃａ＾＋对Ａ３钢腐蚀的影响最显著,Ｃｌ、ＲＳ、ＳＯ４＾２－其次,,ＨＣＯ３     

液膜分离富集和测定镀液中的微量铅

用二环己基－１８－王冠－６（ＤＣ－１８－Ｃ－６）、表面活性剂ＳＰＡＮ８０、中性油ＳＩＯＯＮ－１和溶剂三氯甲烷乳状液膜体系，研究了Ｐｂ２＋的迁移行为。在适宜条件下，８ｍｉｎ内Ｐｂ２＋的迁移率达９９．４％以上，相同条件下，许多金属离子（如Ｎｉ２＋、Ｌｉ＋、Ｋ＋、Ｎａ＋、Ｃａ２＋、Ｍｇ２＋、Ｓｒ２＋、Ｂａ２＋、Ｆｅ３＋、Ａｌ２＋、Ｃｕ２＋、Ｚｎ２＋和Ｃｏ３＋等）均不被迁移，只有Ｐｂ２＋才能从这些离子中分离出来。该方法成功地应用于富集和测定电镀液中的微量铅，相对标准偏差在２．３％以下，结果十分满意。     

Speciation of aluminum in rainwater using a fluoride ion-selective electrode and ion-exchange chromatography with fluorometric detection of the aluminum-lumogallion complex

Soluble aluminum in rainwater was separated into three categories: free aluminum (Al3+), fluoride complexes (sum of AlF2+ and AlF2+), and other forms of aluminum. The free form of the aluminum ion (Al3+) was directly obtained from the separation data of aluminum species according to their charge using gradient elution cation-exchange chromatography. The aluminum fluoride complexes were estimated by combining the data of the free and total fluoride determined using a fluoride ion-selective electrode, with the assumption that 2+ charged aluminum species consisted only of AlF2+. The rest of the aluminum species had a 1+, neutral, or negative charge and mainly consisted of organic complexes. The origin of the organically bound aluminum is discussed. The concentration range of the total dissolved fluoride and aluminum in the rainwater samples was usually in the micromolar to submicromolar range, and the ratio of [T-F]/[T-Al] was found to be between 1 and 4. The speciation of dissolved aluminum into three categories was carried out on the basis of data of 15 rainwater samples collected in the city of Otsu.     

镍铁合金镀液中硫酸镍含量的自动电位滴定

以紫脲酸铵作指示剂的EDTA滴定法在测量镍铁合金镀液中硫酸镍含量时肉眼观察易产生误差.为此,采用自动电位滴定法测定镍铁合金镀液中的硫酸镍含量,用H<,2>O<,2>将镀液中的Fe<'2+>转化为Fe<'3+>,再用三乙醇胺掩蔽Fe<'3+>,以pCa-1型钙离子选择性电极为指示电极,以212型电极为参比电极,在Ca-E...     

Titanium aluminide coating on titanium surface using three-dimensional microwelder

Feasibility of a new method of titanium aluminide coating on titanium surface based on a reaction between aluminum liquid beads and the surface of titanium substrate has been studied using a computer-aided three-dimensional microwelder (3DMW) designed by the present authors. A predetermined length of thin aluminum wire was fed onto the substrate surface, and a spark was stricken from a thin electrode of a W-Ce₂O₃ alloy to make a small aluminum liquid bead on the substrate surface and to simultaneously melt a small area of the substrate surface beneath the bead. All conditions including the length of the wire feeding, the position of the electrode, electric power, etc. had been programmed beforehand. The liquid bead containing aluminum and titanium rapidly solidified on the titanium substrate surface producing titanium aluminides on it. Repetition of the aluminum wire feeding, the electrode positioning and the spark striking produced a coating layer consisting of sub-layers of TiAl₃, TiAl and Ti₃Al from the surface side to the substrate side. Vickers hardness and wear resistance of the coated sample were remarkably improved.     

Electrolytic preparation of Al3Ni fibers from the eutectic alloy,AlAl3Ni

An electrolytic procedure was developed to remove the trialuminum nickel fibers from the aluminum matrix in the eutectic alloy, AlAl₃Ni. The procedure consists of electrolyzing the aluminum matrix at potentials ranging from ?0.8 to +0.5 volts (vs S.C.E.) in a 1$\text{M}$ potassium hydroxide electrolyte. Scanning electron photomicrographs showed that the separated Al₃Ni fibers are intact. Anodic polarization studies with aluminum-nickel alloys illustrated that the presence of nickel protects aluminum from oxidation. Studies with a special fabricated platinum electrode demonstrated that the Al₃Ni fibers are not oxidized within the potential range of ?0.8 to +0.5 (vs. S.C.E.) in a 1$\text{M}$ potassium hydroxide electrolyte. This decreased rate of oxidation of aluminum in the Al₃Ni fibers is correlated with the low rate of diffusion of the aluminum in the Al₃Ni orthorhombic crystals.     

单分散γ-Al_2O_3纳米颗粒制备工艺参数的调控

采用均相沉淀法,在950℃煅烧碱式硫酸铝(Al(SO_4)_x(OH)_y)纳米颗粒2h,制备出单分散的γ-Al_2O_3纳米颗粒。研究了阴离子、浓度和沉淀剂/铝盐摩尔比对Al(SO_4)_x(OH)_y颗粒的形貌、尺寸和分散性的影响。结果表明,Al(SO_4)_x(OH)_y颗粒的最佳制备条件为:二甲胺硼烷(DMAB)作沉淀剂、Al_2(SO_4)_3.18H_2O作铝源、[Al~(3+)]=0.0005mol/L、n(DMAB)/n(Al_2(SO_4)_3·18H_2O)=40。制备出的Al(SO_4)_x(OH)_y具有球形、平均颗粒尺寸为98nm、粒径分布为75~130nm、单分散性的特点;获得了球形、平均颗粒尺寸为90nm、粒径分布范围为50~105nm、单分散的γ-Al_2O_3颗粒。     

碳纳米管导电纸集流体对三元锂离子电池的影响

以碳纳米管导体、纤维素纤维为基体制备碳纳米管导电纸。以此碳纳米管纸为集流体替代铝箔作为集流体组装纽扣电池。三元材料(NMC)为正极活性材料,制成浆料涂敷在碳纳米管纸表面制备成正极。利用Raman光谱、透射电子显微镜(TEM)、扫描电子显微镜(SEM)等进行结构和性能表征。通过恒流充放电检测电化学性能。结果表明:碳纳米管导电纸代替铝箔作集流体,具有更好的电化学性能。在0.1C倍率时,三元/导电纸电极首次放电容量达到184mAh/g,三元/铝箔电极为178mAh/g,相比后者,前者提高了3%,在28次循环后,容量保持率在94%以上。     

活性炭纤维吸附钯的基本特征

用原子吸收分光光度计、Ｘ射线衍等手段，研究了粘胶基活性炭纤维对Ｐｄ＾２＋的吸附。结果表明：活性炭纤维不但能吸附较多的Ｐｄ＾２＋，而且能与Ｐｄ＾２＋发生氧化还原发反应，吸附了Ｐｄ＾２＋的活性炭纤维上出现金属钯颗粒，且粒度较小。     

氯化物三价铬电镀的电化学形核机理

为研究Cr³⁺在金属电极表面的电结晶行为,在氯化物三价铬电镀溶液中,采用电化学工作站测试了Cr³⁺沉积的时间电流曲线,并利用扫描电镜(SEM)分析镀层形貌。结果表明:在镍电极、铜电极和铬电极表面,Cr³⁺的电沉积均经历了成核过程;铜电极和镍电极表面表现为连续成核转为瞬时成核的机理,铬电极的(I/Im)2-t/tm曲线偏离理论曲线较大,但其表现出较正的形核阶跃电位(-1.1 V);随着阶跃电位的负移,3种电极电沉积的电流极大值逐渐增加,电结晶的扩散速率增加,成核数密度减少,镀层由平整光滑逐渐转变为球状晶胞紧密堆砌,晶胞尺寸逐渐增大;在相同的阶跃电位下,铬电极的沉积电流值更小,成核数密度更大,晶胞尺寸更小。     

Poly-cobalt[tetrakis(o-aminophenyl)porphyrin] nanowire and single-walled carbon nanotube for the analysis of hydrogen peroxide

Nanowires of poly-cobalt[tetrakis(o-aminophenyl)porphyrin] (PCoTAPPNW) were fabricated by electrochemical polymerization by the cyclic voltammetric method in anodic aluminum oxide membranes. A glassy carbon electrode (GCE) modified by PCoTAPPNW and single-walled carbon nanotubes (SWNT) without any binder was investigated with voltammetric methods in phosphate buffer saline (PBS) at pH 7.4. The PCoTAPPNW + SWNT/GCE exhibited strongly enhanced voltammetric and amperometric sensitivity towards hydrogen peroxide (H2O2), which shortened the response time (< 5 seconds), showed detection limit of 1.0 microM and enhanced the sensitivity for H2O2 detection with 194 microA mM(-1) cm(-2). The PCoTAPPNW + SWNT/GCE can be used to monitor H2O2 at very low concentration in physiological pH as an efficient electrochemical H2O2 sensor.     

β-PbO_2电镀液中Fe~(3+)含量对PbO_2电极电化学行为及性能的影响

为了探讨低成本高稳定性钛基二氧化铅电极的制备工艺,研究该电极在锌电积液中的电化学性能,在制备β-PbO_2镀层的溶液中加入了有助于镀液稳定的主盐成分Fe~(3+)且使其不被消耗。使用扫描电镜(SEM)研究了β-PbO_2镀层的表面形貌,使用X射线衍射仪(XRD)分析了镀层的晶体物相组成,采用强化寿命测试和热震试验法研究了PbO_2电极的稳定性;在含不同浓度Mn~(2+)锌电解液中,通过阳极极化曲线(LSV)、循环伏安曲线(CV)和交流阻抗谱(EIS)研究了PbO_2电极的电化学行为。结果表明:镀液中掺杂Fe~(3+)获得的β-PbO_2镀层表面均匀致密,不存在明显的铁氧化物;当锌电解液中Mn~(2+)浓度为4 g/L时,PbO_2电极表现出了最优的电催化活性。