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木质素在不同Ru/Nb基催化剂上解聚和脱氧加氢制芳烃化合物(英文) 被引量:6
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作者 马迪 陆圣璐 +2 位作者 刘晓晖 郭勇 王艳芹 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第4期609-617,M0006,共10页
木质素高效转化为芳烃是木质素利用的一个非常重要的过程,一般通过解聚和脱氧加氢反应来实现.我们曾发现NbOx物种在木质素及其模型化合物的C–O键活化和断裂的过程中发挥了至关重要的作用.本文分别选择两种商业的铌基材料(HY-340和NbPO-... 木质素高效转化为芳烃是木质素利用的一个非常重要的过程,一般通过解聚和脱氧加氢反应来实现.我们曾发现NbOx物种在木质素及其模型化合物的C–O键活化和断裂的过程中发挥了至关重要的作用.本文分别选择两种商业的铌基材料(HY-340和NbPO-CBMM)和实验室自制的具有层状结构的氧化铌材料(Nb_2O_5-Layer)为载体,制备了负载型Ru催化剂,将其用于木质素及其模型化合物的催化转化.同时,为了尽量避免Ru与铌基载体相互作用的影响,制备了较为均匀的Ru纳米胶粒并吸附于铌基载体上,得到Ru@铌基催化剂,并用于木质素模型化合物—对甲酚的催化转化反应中.研究表明,木质素在所有的Ru/铌基催化剂上都可以得到比较高的C7–C9碳氢化合物的收率.其中,在Ru/Nb_2O_5-Layer催化剂上C_7–C_9碳氢化合物的摩尔收率为99.1%,选择性为88.0%.采用X射线衍射、N_2吸附-脱附、热重分析、吡啶吸附红外光谱(Py-FTIR)、X射线光电子能谱(XPS)以及CO化学吸附等技术表征了Ru/铌基催化剂的性能与铌基材料的性质、金属Ru颗粒大小及其表面电子状态之间的关系.Py-FTIR结果表明, Nb_2O_5-Layer材料上几乎没有Br?nsted酸,但含有最多的Lewis酸,而NbPO-CBMM上的Lewis酸量最低.结合催化性能数据发现,单体产物收率与铌基载体的Lewis量成正相关关系,其中以Ru/Nb_2O_5-Layer催化剂上最高.CO化学吸附和XPS结果表明,不同的铌基载体负载的金属Ru的分散度和电子状态都有差异.在Ru/Nb_2O_5-Layer上Ru的分散度最好,颗粒尺寸最小,木质素转化得到的芳烃选择性最好;在Ru/HY-340和Ru/NbPO-CBMM上,虽然Ru的分散度相近,但其表面电子状态不同, Ru/HY-340上的金属态Ru带有更多的正电荷δ+,其得到芳烃的选择性高于Ru/Nb PO-CBMM.由此可见, Ru的颗粒尺寸和表面电子状态会影响芳烃选择性.对甲酚催化转化反应结果表明, Ru颗粒大小相同时,铌基载体性质会影响对甲酚转化率;而同一铌基载体上, Ru颗粒大小则影响芳烃选择性,较小的Ru颗粒有利于芳烃的生成. 展开更多
关键词 木质素 芳烃化合物 铌基载体 路易斯酸
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Effects of Naotan Pill on repair of neural cells and cognitive disorders in juvenile rats following hypoxia and ischemia
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作者 Yuxiang Wei Huiqing Zhang +3 位作者 shenglu lu Bingrong Dang Jianping Hong Qingxiang Gao 《Neural Regeneration Research》 SCIE CAS CSCD 2009年第6期455-461,共7页
BACKGROUND: Hypoxia and ischemia induce neuronal damage, decreased neuronal numbers and synaptophysin levels, and deficits in learning and memory functions. Previous studies have shown that lycium barbarum polysaccha... BACKGROUND: Hypoxia and ischemia induce neuronal damage, decreased neuronal numbers and synaptophysin levels, and deficits in learning and memory functions. Previous studies have shown that lycium barbarum polysaccharide, the most effective component of barbary wolfberry fruit, has protective effects on neural cells in hypoxia-ischemia. OBJECTIVE: To investigate the effects of Naotan Pill on glutamate-treated neural cells and on cognitive function in juvenile rats following hypoxia-ischemia. DESIGN, TIME AND SETTING: The randomized, controlled, in vivo study was performed at the Cell Laboratory of Lanzhou University, Lanzhou Institute of Modern Physics of Chinese Academy of Sciences, and Department of Traditional Chinese Medicine of Gansu Provincial Rehabilitation Center Hospital, China from December 2005 to August 2006. The cellular neurobiology, in vitro experiment was conducted at the Institute of Human Anatomy, Histology, Embryology and Neuroscience, School of Basic Medical Sciences, Lanzhou University, and Department of Traditional Chinese Medicine of Gansu Provincial Rehabilitation Center Hospital, China from March 2007 to January 2008. MATERIALS: Naotan Pill, composed of barbary wolfberry fruit, danshen root, grassleaf sweetflag rhizome, and glossy privet fruit, was prepared by Gansu Provincial Rehabilitation Center, China. Rabbit anti-synaptophysin, choline acetyl transferase polyclonal antibody, streptavidin-biotin complex kit and diaminobenzidine kit (Boster, Wuhan, China), as well as glutamate (Hualian, Shanghai, China) were used in this study. METHODS: Cortical neural cells were isolated from neonatal Wistar rats. Neural cell damage models were induced using glutamate, and administered Naotan Pill prior to and following damage. A total of 54 juvenile Wistar rats were equally and randomly assigned into model, Naotan Pill, and sham operation groups. The left common carotid artery was ligated, and then rat models of hypoxic-ischemic injury were assigned to the model and Naotan Pill groups. At 2 days following model induction, rats in the Naotan Pill group were administered Naotan Pillsuspension for 21 days. In the model and sham operation groups, rats received an equal volume of saline. MAIN OUTCOME MEASURES: Neural cell morphology was observed using an inverted phase contrast microscope. Survival rate of neural cells was measured by MTT assay. Synaptophysin and choline acetyl transferase expression was observed in the hippocampal CA1 region of juvenile rats using immunohistochemistry. Cognitive function was tested by the Morris water maze. RESULTS: Pathological changes were detected in glutamate-treated neural cells. Neural cell morphology remained normal after Naotan Pill intervention. Absorbance and survival rate of neural cells were significantly greater following Naotan Pill intervention, compared to glutamate-treated neural cells (P 〈 0.05). Synaptophysin and choline acetyl transferase expression was lowest in the hippocampal CA1 region in the model group and highest in the sham operation group. Significant differences among groups were observed (P 〈 0.05). Escape latency and swimming distance were significantly longer in the model group compared to the Naotan Pill group (P 〈 0.05). CONCLUSION: Naotan Pill exhibited protective and repair effects on glutamate-treated neural cells. Naotan Pill upregulated synaptophysin and choline acetyl transferase expression in the hippocampus and improved cognitive function in rats following hypoxia-ischemia. 展开更多
关键词 Naotan Pill cognition SYNAPTOPHYSIN choline acetyl transferase ceil damage glutamate juvenile hypoxia-ischemia rats
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Efficient upcycling of high-density polyethylene into separable cyclic hydrocarbons
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作者 shenglu lu Yanqin Wang 《Science China Chemistry》 SCIE EI CAS CSCD 2024年第4期1049-1050,共2页
This highlight is inspired by a recent article in Nature Nanotechnology in which Zeng and co-workers[1]from the University of Science and Technology of China reported a strategy for upcycling high-density polyethylene... This highlight is inspired by a recent article in Nature Nanotechnology in which Zeng and co-workers[1]from the University of Science and Technology of China reported a strategy for upcycling high-density polyethylene(HDPE)into separable cyclic hydrocarbons under solvent-and hydrogen-free condition.This work made a significant progress in plastic recycling. 展开更多
关键词 hydrocarbons CYCLING HIGH
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