Coordinating a Three-Lever Supply Chain with Core-enterprise under Demand Uncertainty

在需求不确定的情境下,研究由单一供应商、制造商和销售商组成的三级供应链系统的协调问题。设计了制造商—销售商采用期权契约,制造商—供应商采用回购契约的联合契约协调机制,分析了集中控制、分散控制和协调机制下供应链系统的最优决策。最后,通过数值算例说明了机制设计的有效性,并对分析结果进行验证。研究结果表明,通过制定合理的契约参数可以使供应链各成员的期望利润相比分散决策时有帕累托改进,从而实现三级供应链系统的协调

焙烧及还原温度对Ni-Mg甲烷化催化剂的影响

采用共沉淀-水热复合法制备Ni-Mg/Al2O3催化剂,考察焙烧和还原温度对其结构和甲烷化催化性能的影响,通过XRD,H2-TPR,TEM等表征,发现随焙烧温度升高,催化剂中NiAl2O4物相呈增多趋势,至900℃时,催化剂中镍物种完全以NiAl2O4形式存在,催化剂表面积从500℃焙烧的130m2/g降至900℃焙烧的34m2/g.针对600℃焙烧的催化剂,反应活性随还原温度升高呈现先增加后降低的趋势,其最佳还原温度为650℃,这主要是受Ni物种还原度、还原后Ni晶粒尺寸等多重因素影响.通过关联甲烷化性能与催化剂结构发现,NiO与载体之间相互作用适中,还原后表面能够形成较小的镍晶粒,催化剂具有较好的甲烷化活性和稳定性

焙烧及还原温度对Ni-Mg甲烷化催化剂的影响

采用共沉淀-水热复合法制备Ni-Mg/Al2O3催化剂,考察焙烧和还原温度对其结构和甲烷化催化性能的影响,通过XRD,H2-TPR,TEM等表征,发现随焙烧温度升高,催化剂中NiAl2O4物相呈增多趋势,至900℃时,催化剂中镍物种完全以NiAl2O4形式存在,催化剂表面积从500℃焙烧的130 m2/g降至900℃焙烧的34 m2/g.针对600℃焙烧的催化剂,反应活性随还原温度升高呈现先增加后降低的趋势,其最佳还原温度为650℃,这主要是受Ni物种还原度、还原后Ni晶粒尺寸等多重因素影响.通过关联甲烷化性能与催化剂结构发现,NiO与载体之间相互作用适中,还原后表面能够形成较小的镍晶粒,催化剂具有较好的甲烷化活性和稳定性

Synthesis and application of modified natural gas hydrate kinetic inhibitors based on PVP

Based on polyvinylpyrrolidone（PVP）, two low-dosage kinetic inhibitors for the formation of natural gas hydrates, namely carboxy-modified polyvinylpyrrolidone（PVPCOOH） and amino- modified polyvinylpyrrolidone（PVPNH2）, were synthesized and characterized b

基于PVP改性的水合物抑制剂的合成与应用

在聚乙烯基吡络烷酮（PVP）的基础上合成了两种低剂量水合物动力学抑制剂羧基改性的聚乙烯基吡络烷酮（PVPCOOH）和氨基改性的聚乙烯基吡络烷酮（PVPNH2）。采用FTIR，13CNMR，XPS，GPC等方法对合成的PVPCOOH和PVPNH2进行表征。在蓝宝石高压定容反应釜中研究了PVPCOOH和PVPNH2对甲烷水合物生成过程的影响，并与动力学抑制剂PVP进行了比较；同时考察了PVPCOOH和PVPNH2含量和过冷度对其抑制效果的影响，并对PVPCOOH和PVPNH2的抑制机理进行了分析。表征结果显示，合成的两种物质PVPNH2和PVPCOOH分别为氨基改性的PVP和羧基改性的PVP；根据13CNMR谱图计算出PVPCOOH和PVPNH2的纯度均大于99％；PVPNH2，PVPCOOH，PVP三者的相对分子质量分布均较集中。实验结果表明，PVPCOOH和PVPNH2比PVP的水溶性好；PVPCOOH跟PVP的抑制效果相当，但PVPNH2比PVP的抑制效果差；PVPCOOH和PVPNH2的浓度对最大过冷度的测定无明显影响

Artificial Bee Colony Algorithm Based On Von Neumann Topology Structure

Article Bee Colony (ABC) is one of the most recently introduced algorithms based on the intelligent foraging behavior of a honey bee swarm. This paper proposes a new variant of the ABC algorithm based on Von Neumann topology structure for solving global optimization problems, namely Von Neumann Neighborhood Article Bee Colony (VABC). VABC significantly improves the original ABC in solving complex optimization problems. In this work, VABC algorithm is used for optimizing a set of widely-used benchmark functions and the comparative results produced by ABC. The simulation results showe that the proposed VABC outperforms the original ABC algorithms in terms of accuracy, robustness and convergence speed

transferdehydrogenationofalcoholsoverceriasupportedcuirandpdcatalysts

Ceria-supported Cu, Ir, and Pd catalysts showed quite promising activity for transfer dehydrogenation of cyclohexanol and 2-octanol to cyclohexanone and 2-octanone, respectively, using styrene as the hydrogen acceptor. The Cu/CeO2 and Pd/CeO2 catalysts were more active than the previously reported Cu and Pd catalysts supported on Al2O3, and Ir/CeO2 exhibited extremely high activity. The reactivity of alcohols decreased in the order 2-octanol > cyclohexanol > benzyl alcohol > 1-octanol. The synergetic effect between the metals and CeO2 as well as the effective coupling of dehydrogenation of alcohols and hydrogenation of styrene was responsible for the high catalytic activity

transferdehydrogenationofalcoholsoverceriasupportedcuirandpdcatalysts

Ceria-supported Cu, Ir, and Pd catalysts showed quite promising activity for transfer dehydrogenation of cyclohexanol and 2-octanol to cyclohexanone and 2-octanone, respectively, using styrene as the hydrogen acceptor. The Cu/CeO2 and Pd/CeO2 catalysts were more active than the previously reported Cu and Pd catalysts supported on Al2O3, and Ir/CeO2 exhibited extremely high activity. The reactivity of alcohols decreased in the order 2-octanol > cyclohexanol > benzyl alcohol > 1-octanol. The synergetic effect between the metals and CeO2 as well as the effective coupling of dehydrogenation of alcohols and hydrogenation of styrene was responsible for the high catalytic activity