稀土对镁-铝合金抗热裂性能的影响及其机制

研究了稀土（0.1%～1.2%,质量分数）对Mg-Al合金抗热裂性能的影响及其机制.结果表明： 往Mg-Al合金中添加稀土后,合金的抗热裂性能显著下降,其原因可归为： 稀土引起了Mg-Al合金晶粒粗化,使得热裂纹萌生所需的断裂应变降低;稀土减少了Mg-Al合金中的共晶组织,缩短了枝晶通道保持开通的时间,不利于合金进行补缩;而且稀土还提高了共晶反应的温度,使得凝固后期枝晶间液膜的强度有所下降;当α-Mg枝晶连成骨架时,分布在枝晶间的Al11RE3相容易堵塞枝晶通道,增加了合金补缩的难度;Al11RE3相与α-Mg基体的凝固收缩率不同,容易产生凝固收缩应力,促进热裂纹的萌生.     

镧对ZL702合金高温性能的影响

研究了Ｌａ对ＺＬ７０２合金室温和高温力学性能的影响。Ｌａ与合金中的Ａ１,Ｓｉ,Ｆｅ等元素形成难熔的、分布于晶界的不连续网状金属间化合物,提高了合金的热稳定性。当Ｌａ的加入量为０．１０％～０．１５％（质量分数）时,可使合金获得较佳的综合力学性能。     

四硫富瓦烯四硫醇盐对纳米硫化物表面的修饰

本文报道用四硫富瓦烯四硫醇盐(TTFS₄^4-，简写TTFS₄)修饰CdS、NiS的纳米微粒的方法，通过TEM、FT-IR等手段对修饰的纳米微粒进行了表征。实验发现CdS/TTFS₄的固体荧光强度随着修饰量的增加而逐渐减弱。表面修饰后的CdS和NiS的电导率比修饰前都有提高，后者更为明显。     

铁、氮共掺杂二氧化钛粉末的制备及光催化活性

Using TiCl₄ as the titanium source, nanoparticles of TiO₂ doped with nitrogen(N-TiO₂) were synthesized by triethylamine. TiO₂ powder codoped with iron and nitrogen(Fe/N-TiO₂) were prepared by adsorption-deposition of Fe³⁺ on N-TiO₂ and calcining at 400 ℃ for 2 h. From the XPS results for N1s binding energy at 399.6 eV and 396.6 eV, it is proposed that the partial N atoms as substitution atoms replace for O atoms in TiO₂ lattice. The onset of the absorption spectrum of Fe/N-TiO₂ has a 45 nm red-shift compared with that of TiO₂. The results of photocatalytic degradation of methylene blue solution indicate that Fe/N-TiO₂(0.45% Fe³⁺) has a higher activity. Its photocatalytic activity is about 2 times as high as that of pure TiO₂ under UV-light, and 3 times under sunlight. Doping of nitrogen in TiO₂ enhances photoresponse in visible light region and doping of Fe³⁺ reduces the recombination of electrons and holes. Both of the above effects are beneficial for improving the performances of Fe/N-TiO₂ photocatalyst.     

分别用鲜草与干草生产的鱼腥草注射液指纹图谱对比研究

采用GC-MS分析了21个厂家的鱼腥草注射液指纹图谱。结果发现,采用干草和鲜草生产的注射液的指纹图谱之间存在一定的差异。在药材干燥过程中发现,药材挥发油的含量及主要化合物的含量随干燥时间的变化与鱼腥草注射液的研究结果非常一致,结果说明鲜草注射液与干草注射液指纹图谱之间的差别主要是由于原药材的干燥程度所引起。在鱼腥草注射液指纹图谱标准制定中应该考虑到两类药材的影响。     

SYNTHESES OF ETHYL PERFLUOROACETYLENIC ESTERS AND STEREOCHEMISTRY OF A NOVEL ACETYLENIC ESTER-VINYL ETHER REARRANGEMENT

The intramolecular Wittig reaction has been applied to the syntheses of ethyl trifluoro-but-2-ynoate (2a) and ethyl heptafluoro-hex-2-ynoate (2b). Treatment of 2a and 2b withaqueous sodium hydroxide, followed by acidification, affords 3-ethoxy-4,4,4-trifluoro-2-bu-tenoic acid (3a) and 3-ethoxy-4,4,5,5,6,6,6-heptafluoro-2-hexenoic acid (3b) respectively. Anovel acetylenic ester to vinyl ether rearrangement takes place as thc corresponding methylestors. Their structures are ascertained by elemental analysis and IR and NMR spectra.The stereochemistry of this novel acetylenic ester to vinyl ether rearrangement has been studied.On the basis of ~1H NMR data, we find that the reaction is highly stereoseleetive and the Z-isomer predominated to the extent of above 94% in all cases. The results of the solventeffect of benzene and NOE enhancement in NMR spectroscopy further confirm the configura-tion of the Z- and E-isomer.     

新型Cp'Ti(O-C_6H_4-X)_3茂钛催化剂的苯乙烯间规本体聚合研究

对位卤代的苯酚与五甲基茂三氯化钛在三乙胺存在下进行酯化反应 ,制得五甲基茂基三 (对 卤代苯氧基 )钛的 4种新型化合物Cp Ti(O C6 H4 X) 3(X =F ,Cl,Br,I) .用作主催化剂经甲基铝氧烷 (MAO)和三异丁基铝 (TIBA)活化 ,对苯乙烯间规聚合显示出极高的催化活性 ,催化剂热稳定性好 ,制得的聚苯乙烯间规度、分子量和熔点均高 ,在MAO TIBA Ti =4 0 0 2 0 0 1(摩尔比 ) ,温度 6 0℃时 ,10min催化效率可达 3 4 7× 10 6gPS mol·Ti,MAO TIBA Ti=4 0 0 2 0 0 1时茂钛化合物的催化活性几乎是MAO Ti=6 0 0时的 10倍以上 ;4种茂钛催化剂的活性次序Cp Ti(O C6 H4 F) 3 >Cp Ti(O C6 H4 Cl) 3 >Cp Ti(O C6 H4 Br) 3 >Cp Ti(O C6 H4 I) 3 .     

Studies on PNPP Hydrolysis Catalyzed by Schiff Base Cobalt（Ⅱ） Complexes Containing Benzoaza-15-crown-5

Three novel Schiff base cobalt（Ⅱ） complexes containing benzoaza-15-crown-5, CoL^1, CoL^2 and CoL^3 were synthesized and characterized, and these complexes were used in catalytic hydrolysis of carboxylic ester （PNPP, p-nitrophenyl picolinate） as mimic hydrolytic metalloenzyme. The analysis of specific absorption spectra of the hydrolytic reaction systems indicated that the catalytic hydrolysis involved the key intermediates formed by PNPP with cobalt（Ⅱ） complexes. The CoL^3 bearing the electron withdrawing group shows better catalytic activity due to its stabilization effect on active species MLS^-. The catalytic mechanism of PNPP hydrolysis was also proposed. The kinetic parameter of PNPP catalytic hydrolysis has been calculated and the activation energy for the catalytic hydrolysis is 43.69, 39.76 and 35.44 kJ·mol^-1, respectively.     

取代查耳酮肟电化学氧化机理的研究

研究了７种取代查耳酮肟的电化学行为。用氢氧化钠底液热解石墨工作电极，取代查耳酮肟的电极过程为１ｅ氧化不可逆吸附电极过程。它们的氧化电位随取代基吸电子能力的增强而增高，并与它们相应的Ｈａｍｍｅｔｔ常数呈线性关系。取代查耳酮肟的电化学氧化机理为先失去一个电子生成ｉｍｉｎｏｘｙ自由基，然后由基对分子内烯键进行环化加成，脱氢后形成３，５－二聚代异恶唑。用控电位电解和紫外吸收光谱检测了部份电化学氧化产物，证     

聚电解质复合物

本文介绍了聚电解质复合物的研究及发展状况，包括聚电解质复合物的形成、结构以及影响形成聚电解质复合物的各种因素，还介绍了近年来以聚电解质复合物为材料 质的渗透汽化膜的应用和在生物医药方面的研究成果。