零售商基于再订货付款的订购策略

供应商为促销其新产品,往往允许零售商再订货付款。基于两级信用支付,在EOQ框架下,研究了供应商实施允许零售商再订货付款策略下,零售商的订购策略。通过分析成本函数,提出了使零售商成本最小化的最优订购周期和最优订货量的决策算法。最后通过算例进行了验证。这为供应商促销其新产品提供了理论依据。     

3-连通[5,3]-图的Hamilton性

如果一个图的任意s阶导出子图中至少含有￡条边,则称这个图为[s,t]-图．用G3表示任意3阶图,证明了3-连通[5,3]-图是Hamilton图或者同构于K^-4VG3．     

正偶数分拆成若干个连续偶数之和的分拆种数

给出了正偶数分拆成若干个连续偶数之和的分拆种数的计算公式,并对其进行了应用．     

一类具有高阶奇点的三次系统

本文研究了具有一个有限远奇点和一个无穷远奇点的一类三次系统.给出了极限环存在性或不存在性的一些条件,证明了如果极限环存在,则一定是集中分布的,并作出了系统无初等奇点时的全局相图.     

一种以业务流程为中心的信息系统设计方法

首先对传统的信息系统规划方法和业务流程重组思想进行了阐述,分析了传统信息系统设计方法中存在的问题,然后基于实践提出以业务流程为中心系统设计方法的步骤,最后说明了以业务流程为中心的系统设计方法的优势所在。最后以某物流公司的商务信息系统设计为例证明了该系统设计方法的有效性。     

欧几里德最短2-连通Steiner网络的性质

称连接平面上给定点集的最短2-连通Steiner网络为欧几里德最短2-连通Steiner网络。给出了欧几里德最短2-连通Steiner网络的两个性质。     

模糊控制算法在干线信号绿波控制中的应用研究——以虎门镇连升路为例

从交通信号控制的角度,对城市干道的交通信号控制策略及其控制优化参数（周期时长、绿信比、相位差）进行分析,并结合虎门镇连升路的交通状况,采用模糊控制方法实现城市交通干道的优化协调控制。通过VISSIM软件仿真,分析对连升路分别采用模糊协调控制方案、传统数解法协调控制方案及单点控制方案的效果并进行比较,结果表明模糊协调控制方案明显优于其他两种方法。     

Regulation of mitochondrial aconitase by phosphorylation in diabetic rat heart

Mitochondrial dysfunction and protein kinase C (PKC) activation are consistently found in diabetic cardiomyopathy but their relationship remains unclear. This study identified mitochondrial aconitase as a downstream target of PKC activation using immunoblotting and mass spectrometry, and then characterized phosphorylation-induced changes in its activity in hearts from type 1 diabetic rats. PKCβ₂ co-immunoprecipitated with phosphorylated aconitase from mitochondria isolated from diabetic hearts. Augmented phosphorylation of mitochondrial aconitase in diabetic hearts was found to be associated with an increase in its reverse activity (isocitrate to aconitate), while the rate of the forward activity was unchanged. Similar results were obtained on phosphorylation of mitochondrial aconitase by PKCβ₂ in vitro. These results demonstrate the regulation of mitochondrial aconitase activity by PKC-dependent phosphorylation. This may influence the activity of the tricarboxylic acid cycle, and contribute to impaired mitochondrial function and energy metabolism in diabetic hearts. Received 31 October 2008; received after revision 17 December 2008; accepted 2 January 2009     

绿色再制造管理层次网络分析模型及应用

绿色再制造管理是对产品再制造加工各个环节进行管理的有效模式。针对目前绿色再制造实施过程环节多,影响因素复杂,再制造实施缺乏系统研究的现状,分析了绿色再制造战略实施的影响因素和控制要素,提出了一种集成绿色再制造各个环节的层次网络分析模型。基于ANP分析理论,用实例说明了采用ANP法进行绿色再制造管理战略决策的过程。     

Sea urchin embryo as a model for analysis of the signaling pathways linking DNA damage checkpoint,DNA repair and apoptosis

DNA integrity checkpoint control was studied in the sea urchin early embryo. Treatment of the embryos with genotoxic agents such as methyl methanesulfonate (MMS) or bleomycin induced the activation of a cell cycle checkpoint as evidenced by the occurrence of a delay or an arrest in the division of the embryos and an inhibition of CDK1/cyclin B activating dephosphorylation. The genotoxic treatment was shown to induce DNA damage that depended on the genotoxic concentration and was correlated with the observed cell cycle delay. At low genotoxic concentrations, embryos were able to repair the DNA damage and recover from checkpoint arrest, whereas at high doses they underwent morphological and biochemical changes characteristic of apoptosis. Finally, extracts prepared from embryos were found to be capable of supporting DNA repair in vitro upon incubation with oligonucleotides mimicking damage. Taken together, our results demonstrate that sea urchin early embryos contain fully functional and activatable DNA damage checkpoints. Sea urchin embryos are discussed as a promising model to study the signaling pathways of cell cycle checkpoint, DNA repair and apoptosis, which upon deregulation play a significant role in the origin of cancer. Received 10 April 2007; accepted 23 April 2007