厌氧氨氧化研究进展

厌氧氨氧化是近年来发现的新型生物脱氮途径。综述了厌氧氨氧化反应的由来、可能的反应机理、厌氧氨氧化微生物、厌氧氨氧化工艺的研究及应用并指出了今后的研究方向。     

马来酸酐接枝 SEBS对聚丙烯 / 碳纳米管复合材料性能的影响

采用球磨和熔融共混法，制备了聚丙烯（PP）／碳纳米管（CNT）／马来酸酐接枝SEBS（MA－SEBS）复合材料，结果表明，MA－SEBS促进了CNT在PP基体中的分散，形成完善的逾渗网络，改善了PP／CNT复合材料的抗静电性，提高了CNT对PP的增强作用，对PP／CNT复合材料有明显的增韧作用。     

抗疟新药——蒿甲醚胶囊稳定性的研究

蒿甲醚为我国首创的一种抗疟特效药。用３种方法对蒿甲醚胶囊的稳定性进行了考察，结果表明本品室温避光条件下至少可保存２ａ。     

Nd2O3掺杂BaTiO3陶瓷的结构和电性能研究

研究了组份为Ｂａ１－ｘＮｄｘＴｉＯ３（ｘ＝０．００２－０．０４）陶瓷的结构和电性能，实验结果表明：当０．００２≤ｘ≤０．００４时，轻度Ｎｄ２Ｏ３掺杂的ＢａＴｉＯ３陶瓷呈半导体；而当０．０１２≤ｘ≤０．０４时呈绝缘性。ＢａＴｉＯ３陶瓷的室温电阻率ρｖ随Ｎｄ＾３＋含量的变化呈Ｕ型特曲线。组份为Ｂａ０．９９７０Ｎｄ０．００３０ＴｉＯ３的材料具有最低的ρｖ和最佳的ＰＴＣＲ效应，相应于最大的平均晶粒尺寸和最     

含活性二氧化硅蓖麻油型聚氨酯互穿网络的物理性质

以Ｎ，Ｎ－二甲基苯胺，１％（按ＩＰＮ质量计，下同）过氧化二苯甲酰和二丁基二月桂酸锡（简称有机锡）为固化剂，活性二氧化硅为填充剂（用量为总质量的３０％），由４７％的甲基丙烯酸甲酯与蓖麻油，２，４－甲苯二异氰酸酯型聚氨酯组成的ＩＰＮ为基材，在２５－３０℃下经８－１２ｈ固化。固化材料的体积电阻率和表面电阻率可达１０＾１３数量级，介电常数为５．５－６．０，介电损耗角正切为０．０１８－０．０２０，拉伸强度为     

Aboveground nitrogen in relation to estimated total plant uptake in maize and bean

The main objective of this field study was to estimate the total plant uptake of soil mineral N in maize (Zea mays L.) and common bean (Phaseolus vulgaris L.) grown in crop rotations under different N content in Nicaragua. Secondary objectives were to estimate the fraction of the measured soil mineral N content taken up in this way, and to determine how the measured N in plant aboveground parts was related to the total mineral N uptake. A large variation in N content was obtained by using data from fertilisation experiments. Plant total N uptake was estimated as the residual N in a mass balance calculation of soil mineral N. Mineral N content in the top 0–0.3 m soil layer in the field cultivations and in tubes isolated from root uptake, and N content in aboveground plant parts were measured every 30 days. Estimated plant total uptake of soil mineral N varied considerably (2.5–14 g N m⁻² 30 day⁻¹) over periods and N treatments. The range of variation was similar for maize and bean. The fraction of the soil mineral N that was taken up by the plant daily varied more in maize (about 0.03–0.12 day⁻¹) than in bean (about 0.05–0.08 day⁻¹). Our results suggest that monthly changes in N in aboveground plant parts were linearly related to plant total N uptake during the same period. Aboveground plant N constituted between about 55% and 80% of total uptake of soil mineral N in maize depending on period within season, whereas for bean it was more constant and smaller (about 40%).     

金属离子(Na+、K+、Mg2+、Ca2+)与鸟嘌呤活性位点相互作用的理论研究

本文用量子化学从头算方法对金属离子与碱基活性位点的相互作用及其形成配合物的结构和性质进行理论研究.用HF/6-311G*优化鸟嘌呤及其金属离子(Na 、K 、Mg2 、Ca2 )配合物.在HF水平上,运用6-311G*基组计算Ⅰa和Ⅱa族金属离子(Na 、K 、Mg2 、Ca2 )与鸟嘌吟(Guanine)活性位点的相互作用.结果表明:Mg2 、Ca2 离子引起配位体的变形较Na 、K 离子大;Mg2 、Ca2 离子配合物比Na 、K 离子配合物稳定.     

Study of thermally poled and corona charged poly(vinylidene fluoride) films

The effect of thermal poling and corona charging on the structure and characteristics of poly(vinylidene fluoride) films (PVDF) was investigated. The structure and chemical change of PVDF films with different polarizing treatments was examined using Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy, respectively. The characteristics including piezoelectric coefficients, ferroelectric hysteresis, and leakage current were measured. It was found that both polarized methods contribute to dramatic improvement on the piezoelectricity and ferroelectricity of PVDF films, while thermal poling leads to structure change with the generation of new carbon composition. The reason to cause leakage current was also analyzed. POLYM. ENG. SCI., 47:1344–1350, 2007. © 2007 Society of Plastics Engineers     

泡沫塑料加工过程中的气泡成核理论(Ⅱ)——剪切能成核理论及其发展

介绍了剪切流场中泡沫塑料加工的气泡成核理论,分析评述了剪切流场中泡核拉伸模型、空穴成核模型对气泡成核机理的解释及存在的不足;对静态熔体中气泡成核过程进行了能量描述;介绍了最新的气泡成核中的剪切能成核理论,该理论较完善地解释了剪切流场中气泡成核过程;最后指出了气泡成核理论研究的发展方向。