纳米粒子催化剂及其研究进展

纳米粒子催化剂是一种新型的高效催化剂。本文综述了纳米粒子催化剂的特性及其制备方法，并介绍了纳米粒子催化剂的应用状况。     

高分子体系阻燃剂研究的新进展

介绍了新技术在高分子阻燃领域的应用，其中包括微胶囊化技术、纳米技术、无机阻燃剂的改性技术以及阻燃剂的复配技术，并指出了阻燃剂领域未来研究方向。     

Rim Structure in Ti(C0.7N0.3)–WC–Ni Cermets

The evolution of rim structures during the liquid-phase sintering of Ti(C_0.7N_0.3)· x WC·20Ni ( x = 5–25 wt%) was investigated under a variety of sintering conditions and densification procedures. In addition, the onset of formation of the surrounding structures in the system was examined by analyzing the microstructures and rim compositions. The compositions of the inner and outer rims were found to vary with sintering temperature and holding time. The results indicate that the inner rim forms at sintering temperature and the outer rim forms thereafter during the sintering or cooling stage of sintering. The coalescence of Ti(C,N) appears to occur at the sintering temperature to a great extent before the formation of the rim phases.     

纳米SiC和微米SiC填充聚醚醚酮的磨损机理研究

利用热压法分别以纳米ＳｉＣ和微米ＳｉＣ作为填产制取了两类不同ＳｉＣ填充的聚醚醚酮复合材料，并对它们在干摩擦条件下的摩擦磨损性能进行了研究，同时还用扫描电子显微镜对摩擦表面形貌进行了观察，进而对材料的磨损机理作了分析与讨论。研究结果表明，１０％（ｗｔ）纳米ＳｉＣ作为填料能有效的改善其填充聚醚醚酮的摩擦磨损性能，而相同含量的微米ＳｉＣ作为填为只能使其填充聚醚醚酮的耐磨性能有所改善，但没有减摩效果。微米     

聚丙烯共混改性的研究

以聚丙烯为原料，加入适当的纳米填料、偶联剂、成核剂和相容剂对聚丙烯进行共混改性，以提高聚丙烯在常温下的力学性能，扩大其应用范围。实验结果表明，加入不同的改性剂对聚丙烯的力学性能均有不同程度的影响。     

电镀镍层对金属封装外引线弯曲疲劳性能的影响

笔者系统地研究了改善金属封装外引线抗弯曲疲劳的方法。发现各种类型的电镀镍层对外引线弯曲疲劳性能有不同的影响,其中在氨基磺酸镍镀液中,采用多波形电流电镀时外引线抗弯曲疲劳的性能最好。另外,用H2作为保护气体,对引线弯曲性能较差的镀覆亮镍的金属封装进行退火,也能明显改善外引线的抗弯曲疲劳能力。     

以NiSO_4／γ－Al_2O_3为催化剂丙烯齐聚两段反应法制壬烯和十二烯新工

研究了以ＮｉＳＯ＿４／γ－Ａｌ＿２Ｏ＿３为催化剂丙烯齐聚两段反应法制壬烯和十二烯的新工艺。考察了反应温度、空速及溶剂稀释等工艺条件的影响及在第二个反应器前添加丙烯的效果。当两段串联反应器的第一段和第二段的反应温度分别为６０℃和８０℃，反应压力为３．２ＭＰａ，丙烯的液体体积空速（ＬＨＳＶ）为１．５ｈ￣（－１）时，丙烯转化率达９６．５％，壬烯和十二烯的选择性分别为２７．９％（ｗ）和２９．６％（ｗ）。若按二聚物返回反应体系计，目的产物总选择性达８０％。     

钠作助剂的Ni／Al_2O_3上的CO_2加氢反应

用稳定态活性测试法研究了一系列不同载钠量Ｎｉ／Ａｌ_２Ｏ_３催化剂上的ＣＯ_２加氢甲烷化行为，并对它们进行了ＸＲＤ和程序升温还原表征。实验结果表明，在所用钠量范围内，于Ｎｉ／Ａｌ_２Ｏ_３上的ＣＯ_２加氢生成甲烷的活性随Ｎａ加入量的改变而变化，这与催化剂上Ｎｉ物种的分配有关，６７３Ｋ附近还原出的Ｎｉ物种可能是良好的ＣＯ_２加氢甲烷化活性中心。Ｎａ助剂的作用主要是改变Ｎｉ物种的分配。通过Ｎａ助剂的加入，可获得在化学剂量ＣＯ_２／Ｈ_２比下使ＣＯ_２几乎完全转化为甲烷的低镍催化剂。     

用电导法测定镍合金中的镍

提出用丁二酮肟乙醇溶液滴定、电导法确定终点测定镍合金中镍的新方法。在氨性溶液中滴定，铜（Ⅱ）、锰（Ⅱ）、钴（Ⅱ）的干扰通过掩蔽或氧化的方法消除，其它金属离子对测定没有干扰。本方法不受溶液颜色和浊度的影响，试剂用量少，具有准确、快速、干扰少的特点，已用于镍合金中镍的测定，获得了精密度高、准确度好的分析结果。     

Biosorption of heavy metals (Cd,Cu, Ni,Pb, Zn) by chemically-reinforced biomass of marine algae

Particles of two different sizes (0·105–0·295 mm and 0·84–1.00 mm diameter) of two marine algae, Sargassum fluitans and Ascophyllum nodosum, were crosslinked with formaldehyde (FA), glutaraldehyde (GA) or embedded in polyethylene imine (PEI), followed by glutaraldehyde crosslinking. They were used for equilibrium sorption uptake studies with cadmium, copper, nickel, lead and zinc. The metal uptake by larger particles (0·84–1·00 mm) was higher than that by smaller particles (0·105–0·295 mm). The order of adsorption for S. fluitans biomass particles was Pb > Cd > Cu > Ni > Zn, for A. nodosum copper and cadmium change places. Uptakes of metals range from q_max = 378 mg Pb g^?1 for S. fluitans (FA, big particles), to q_max = 89 mg Zn g^?1 for S. fluitans (FA, small particles) as the best sorption performance for each metal. Generally, S. fluitans is a better sorbent material for a given metal, size and modification, although there were several exceptions in which metal sorption by A. nodosum was higher. The metal uptake for different chemical modifications showed the order GA > FA > PEI. A comparison of different sorption models revealed that the Langmuir sorption model fitted the experimental data best.