聚合条件对载体催化剂催化性能的影响(Ⅱ)

研究了聚合条件对载体稀土催化剂催化性能的影响,发现聚合物的分子质量、聚合物转化率、聚合物的微观结构均随反应条件不同而呈现规则变化．     

佳木斯地区的珍稀蝶类资源

从1996—2004年,在佳木斯地区进行蝶类资源的系统调查研究,共采集到蝴蝶标本3000余件,隶属于7科91属192个品种,其中属于佳木斯地区珍稀种类的有6科11属12种．珍稀蝶类由于环境的破坏而逐渐减少,保护珍稀蝶类是所有生物科研人员的一项重要任务,我们将继续进行这些蝶类的生物学特性及饲养方面的研究,扩大珍稀蝶类的种群数量,维持生态多样性,并倡议进行环境保护。     

曝气对河流沉积物中重金属Cu,Pb,Zn和Cd释放的影响

采用模拟实验研究了长春市伊通河沉积物中重金属Cu,Pb,Zn和Cd在曝气条件下的释放规律, 利用Tessier连续萃取法分析曝气前后沉积物中重金属的形态变化. 结果表明, 4种重金属的释放速率和过程各不相同, Zn的释放速率远远小于Pb和Cd, Cu在整个实验过程中浓度变化缓慢. Pb和Zn在曝气一段时间后均出现再吸附或共沉降现象. 所研究样品的金属释放出现峰值时间较快, 存在着较大的生态风险性. 沉积物中的重金属经过曝气后也由原来相对稳定的存在形态逐渐向生物易于吸收的结合态转化, 增加了重金属的生物毒性.     

表面活性氧物种对A-H(A=C,O,N)键活化机理的研究进展

表面吸附态活性氧物种如O~*、OH~*等对H_2O、CH_3OH、CH_4、NH_3所含O-H、C-H以及N-H键的活化有着十分重要的作用,其调控行为与催化剂的本身电子结构、氧物种的碱性以及A-H中H原子的酸性等有着非常密切的关系.通过表面吸附氧物种的修饰可以有效地控制A-H键的活化程度,从而达到调控反应的目的.利用40篇文献综述了近些年来理论科学工作者在该方面的研究成果,期望为实验工作提供有价值的理论指导依据.     

稀土对藻类生长影响的研究进展

三十年来,针对稀土对藻类的生长影响已经得到了较多研究.它主要表现在两个方面:一是针对防治水体富营养化而开展的稀土元素对藻类的生长影响研究;另一方面是以养殖经济藻类为目的而开展的研究工作.文章从这两个角度出发,综述稀土对藻类生长的影响研究进展,并在此基础上指出今后重点研究方向.     

高压氢气对金属材料断裂韧性的影响

基于应力诱导氢扩散理论、氢致键合力降低理论和线弹性断裂力学理论,提出了一个描述氢气对金属断裂韧性影响的数学模型,用于定量预测金属在氢气中的断裂韧性.结果表明,当已知金属在低压氢气中的断裂韧性时,利用所提出的模型可以外推出金属在高压氢气中的断裂韧性,从而避免了在高压氢气中测量金属断裂韧性所带来的危险性.同时,利用文献报道的几种金属材料在不同氢气压力下的断裂韧性试验值对模型进行验证发现,所建立的模型对预测金属在氢气中的断裂韧性具有较好的有效性.     

抄本《张说之文集》字书未录仨罕见字考

清抄宋蜀刻本《张说之文集》三十卷，是海内仅存孤本，因此，少有人知。其中有三个字，其形不见于古今字书。经研究，“”应是误写，“”是异体，“”或为唐宋人新造字。     

“地理”和“地理学”探源

中国古人一直秉承“天圆地方”的地理观,到明末清初才有所改变。当时西方的地理学说已经传入我国,“地圆说”开始见诸汉语文献。反映到语言上,最值得注意的则是“地理”一词含义的变化。文章试图讨论“地理”和“地理学”含义的演变,从词语的角度揭示西方地理观在中国的传播过程。     

The poisoning and regeneration effect of alkali metals deposed over commercial V2O5-WO3/TiO2 catalysts on SCR of NO by NH3

In this study, commercial V2O5-WO3/TiO2 catalysts were deactivated by loading with alkali metals （K and Na）. These catalysts were then regenerated by washing with either deionized water or 0.5 mol/L H2SO4 （through the ultrasonic-assisted method）. The samples used in this research were characterized by NH3-temperature programmed desorption （TPD）, and X-ray photoelectron spectroscopy （XPS）. Results showed that Na2O and KaO doping can poison the V2O5-WO3/TiO2 catalyst and that the poisoning effect of Na2O was stronger than that of KaO. However, the Na2O-loaded sample was easier to regenerate than the KaO-loaded sample. The surfaces of catalysts can be sulfated by washing with dilute sulfuric acid because strong acid sites adhere to the catalyst surface. SO42- could also promote catalyst activity. As indicated by the NH3-TPD findings, the deposition of Na2Oand K2O could also reduce the amount of desorbed ammonia and destabilize the acid sites, especially strong chemisorption sites. XPS results revealed that catalysts were deactivated by the decrease in the concentration of chemisorbed oxy- gen [the Oα（Oα ＋ Oβ） ratio]. In the Na2O-doped catalyst, much chemisorbed oxygen was lost （from 28.8 % to 10.6 %）. However, the decrease in the Oα（Oα ＋ Oβ） ratio was less significant in the K20-doped catalyst （from 28.8 % to 23.5 %）. Nonetheless, the binding energies of Ols broadened with respect to both high and low energy. Inparticular, the binding energy of chemisorbed oxygen increased from 531.5 to 531.8 eV.     

Synthesis,Characterization, and Luminescence Properties of a Multi-benzoic Acid Rare Earth Complex Applied to Fluorescence Nanometer and Micrometer Fiber

The design and synthesis of a novel multi-benzoic acid ligand and the luminescence properties of the rare earth complex with the ligand and Eu3 ＋were focused on. The composition and structure of ligand and complex were characterized by Fourier transform infrared（ FT-IR） spectroscopy,1H nuclear magnetic resonance（1H NMR） techniques, and element analysis. The luminescent properties,heat resistant performance,morphology and distribution in fibers of the complex were also measured. The fluorescent spectra indicate that as-synthesized complex owns excellent luminescent properties. The maximum relative fluorescence intensity of the complex is more than 7 000. The thermo-gravimetric analysis（ TGA） results confirm that the initial degradation temperature of as-synthesized complex is at 413 ℃. Transmission electron microscope（ TEM） and field-emission scanning electron microscope（ FESEM） photos show that the particle size of assynthesized complex is 50-60 nm,and can be uniformly distributed in fiber. Based on these results, it can be concluded that the synthesized complex has excellent luminescent properties, good thermal stability,and extensively application prospect.