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961.
采用离子交联法,以高纯竹叶碳苷黄酮制剂(碳苷总质量分数﹥90%,记为H-BLF)和芫根阴离子多糖(TP)为原料,通过ε-聚赖氨酸(ε-PL)的阳离子桥键合而成竹叶碳苷黄酮纳米混悬液(H-BLFnd),进一步在混悬液中添加8%(w/v)的γ-环糊精、经真空冷冻干燥得到纳米冻干粉(H-BLFnp),采用粒径分析、TEM、UV、FTIR、TG和DSC对其外观、性能、结构进行表征。结果表明: H-BLFnp外观为白色粉状,表面光洁平整,色泽均匀,平均粒径为(679±10.2)nm,分散系数为(0.349±0.004),包埋率为(92.39±0.34)%。 相似文献
962.
963.
抗人 A 血型杂交瘤15B_4细胞在 CelliGen 细胞培养罐中进行连续灌注培养,细胞密度达1.6×10~7/ml。每天灌注新培养液量由1000ml 增到2300ml,第14天后又逐日减少至1000ml,死细胞数随着转速的增加和灌注量的减少而增多。血凝效价呈梯度上升,滴度达到2~(14),相当于腹水效价。培养6天 IgM 产量为0.2克/升/天,10~18天波动在1.45~1.8克/升/天。15B_4细胞代谢与葡萄糖、乳酸有关,与氨无关。CelliGen 自控效果较好,适用于杂交瘤细胞的高密度培养。搅拌速度在120~150r/min 对细胞产生的剪切力有明显地破坏作用。溶氧控制系统有待改进。 相似文献
964.
T. Giornelli A. Lfberg L. Guillou S. Paul V. Le Courtois E. Bordes-Richard 《Catalysis Today》2007,128(3-4):201-207
Catalytic wall (structured) reactors and structured supports are suitable to study the catalytic properties of nanosized materials. The coating of metallic (aluminum and stainless steel) plates by thin layers of active phase is presented in two cases, VOx/TiO2 and Co/SiO2, catalysts used in the oxidative dehydrogenation (ODH) of propane and in Fischer–Tropsch synthesis (FTS) of clean fuels, respectively. The preparation of coated plates and their characterisation by various methods of physicochemical analysis are described. Both chemical and physical methods were used for coating. VOx/TiO2 layers were obtained by grafting of Ti (on Al or stainless-steel plates) and V (on TiO2) alkoxides and use of sol–gel media or suspension. A silica primer was deposited (on stainless-steel plate) by plasma-assisted chemical vapour deposition (PACVD) onto which Co oxide and silica were coprecipitated from sol–gel. The catalytic experiments in the respective reactions were carried out in special plate reactors and compared with those of catalytic powders. The study shows that the coating of a metallic substrate by a catalyst is not straightforward and requires specific studies dealing with both chemistry (chemical affinity between substrate and catalytic layers) and catalytic engineering (catalytic performance in taylor-made reactors). 相似文献
965.
LIHuili LINan WEIYaowu 《中国耐火材料》2003,12(3):30-33
The effects of refractories of quarz-corundum consisting of 45 mass% quartz and 55 mass% corundum,fused corundum and fused magnesia on the total axygen content(TOC) and the composition of inclusions in intersitital free(IF) steel were studied,3 mass% microsilica was added into the three refractories as binder.The refractories were shaped as lining of the graphite crucible by castable method IF steel was placed in the crucibles,then they were heated at 1600℃ for 90min and 45min respectively.Oxygen contents of the steel samples were obtained by axygen determinator.Inclusions were analyzed by SEM and EDS.The results show that the TOC of steel increase with ncrease of Index of Oxygen Potetial (IOP) of the refractories.The steel sample coped with MgO refractories having the lowest IOP has the lowest TOC. 相似文献
966.
因为制冷设计不合理,施工不专业,都会影响数据中心机房的制冷效率。该文介绍三种数据机房的高效制冷方法:按需制冷;水平送风;封闭冷通道。研究数据机房的高效制冷,不仅是节能减排的需要,也是保障数据机房稳定运行的需要。 相似文献
967.
The electrochemical characterization of 304 stainless steel in 0.1–0.5m Na2SO4 and Na2SO4 + NaHCO3 aqueous solutions at pH8 was done in combination with SEM surface analysis. Passivation of the surface film without any pitting events is observed for the current–potential and current–time experiments, and no anodic current spikes, which are associated with depassivation events, are distinguishable above the background current level. However, SEM pictures of an electrode surface polarized at potentials above 0.4V show microscopic pit nucleation. Even when the metal may be regarded as passive from a current–time or current–potential characteristics, passivity is not stable and localized film breakdown can still occur. The events are ascribed to pit nucleation at the active inclusion sites. The pits do not grow even into the metastable state but die through repassivation by metal salt precipitation immediately after birth. The effect is ascribed to the solubility of metal salts with the electrolyte produced by dissolution in the nucleation sites. The results show that pit nucleation and pit growth are two distinct processes. The importance of solution composition and the protective effect of bicarbonate ions is also discussed. 相似文献
968.
Gang Liu Huamin Zhang Hexiang Zhong Jingwei Hu Dongyan Xu 《Electrochimica acta》2006,51(26):5710-5714
A novel Pt4ZrO2/C catalyst was prepared and compared with 20 wt.% Pt/C in terms of the sintering resistance and corrosion resistance. To evaluate their sintering resistance and corrosion resistance properties, an accelerated ageing test (AAT) was performed. The catalysts before and after AAT were characterized by cyclic voltammetry (CV), rotating disk electrode (RDE) and X-ray diffraction (XRD). After AAT, the dissolution rate of Pt and Zr in H3PO4 media (105 wt.%, 204 °C) was characterized by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The electrochemical area (ECA) changes of thin film electrodes based on Pt4ZrO2/C and Pt/C catalysts were also evaluated using continuous CV sweep technique. All the results showed that Pt4ZrO2/C has higher sintering resistance and corrosion resistance than Pt/C. ‘Anchor effect’ is proposed to explain the enhanced effect of ZrO2 in Pt4ZrO2/C binary catalyst compared with Pt/C that contain platinum alone. 相似文献
969.
建设创新型国家是我们中华民族的历史责任。“自主创新、重点突破、支撑发展、引领未来”的16字方针应当成为我们未来创新活动的指南。建设创新型国家把自主创新放在首位,并提出了引领未来的高标准要求。钢铁科技创新必须突出重点,抓住创新成果产业化这个关键,支撑起行业和国民经济的发展。 相似文献
970.
叶树滋 《硫磷设计与粉体工程》2007,(5):34-37
试验表明,用钛白粉生产中副产的w(H2SO4)≈20%的钛白废酸,经浓缩、净化及再稀释后与磷矿粉反应,在加入净化添加剂的条件下制得纯净的湿法磷酸与氨或碳酸氢铵反应,可代替热法磷酸为原料生产相同质量的高纯度磷酸一铵。分析了该工艺的技术可行性和经济可行性,认为所得的纯净磷酸也可加工成其他高纯度磷化工产品。 相似文献