共查询到20条相似文献，搜索用时 109 毫秒
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研究了在供应中断下具有随机需求的闭环供应链系统的最优差别定价模型.基于博弈论的理论和方法分别在集中式和分散式决策情形下,确定了最优批发价、最优销售价、最优订购量及系统利润. 最后通过数值例子对最优差别定价模型进行了实证分析. 相似文献
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研究存在模型风险的最优投资决策问题，将该问题刻画为投资者与自然之间的二人-零和随机微分博弈，其中自然是博弈的“虚拟”参与者.利用随机微分博弈分析方法，通过求解最优控制问题对应的HJBI(Hamilton-Jacobi-Bellman-Isaacs)方程，在完备市场和存在随机收益流的非完备市场模型下，都得到了投资者最优投资策略以及最优值函数的解析表达式.结果表明，在完备市场条件下，投资者的最优风险投资额为零，在非完备市场条件下最优投资策略将卖空风险资产，且卖空额随着随机收益流波动率的增大而增加，随风险资产波动率增大而减少. 相似文献
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本文给出了在加性随机噪声干扰下锁相环(PLL)对于非调制正弦波计算相位误差方差的最优闭环传递函数的表达式.这个问题在传统的锁相环理论中已作了广泛的讨论,不过这些讨论都是在平稳噪声干扰下作出的.然而工作在有平稳噪声干扰的脉冲调幅波下的同步器就不能作为平稳过程处理了.本文证明了在这种情况下根据传统PIL理论得到的最优传递函数并非最优,进一步在更带普遍性的噪声干扰下推导出了最优闭环传递函数,使之适用于绝大多数类型同步器。 相似文献
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在随机需求条件下建立了由一个制造商和一个零售商所组成的闭环供应链差别定价模型。 在制造商成本信息对称和信息不对称情况下,分别讨论了闭环供应链的最优差别定价问题,得到了在不 同信息条件下的最优定价组合以及最优的订购量. 最后通过数值算例分析了成本信息不对称对两种产品 的零售价以及订购量的影响. 相似文献
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研究最小化生命期破产概率准则下的最优投资问题.假设投资者具有财富依赖型线性消费率,运用最优随机控制理论,通过求解模型相对应的HJB方程,我们得到了投资者生命期内破产概率取最小值的最优投资策略及相应的最小破产概率.最后,给出了一个应用例子.结果表明,在最优评价标准为最小化破产概率时,死亡风险对投资者具体投资行为的影响是不可忽视的. 相似文献
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在随机双曲折现条件下，显式地给出了具有指数函数（CARA）效用的最优跨期消费与投资组合；在非完备市场下，显式给出了基于CARA效用的收益流的效用无差别价格.结果表明：最优投资比例以及收益流的价值不受随机双曲折现因子的影响；在低折扣阶段，本文的最优消费水平高于Merton模型下的对应值，低折扣时期越短或高低折扣值相差越大，消费差距越明显. 相似文献
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王子今 《湖南农业大学学报(自然科学版)》2016,(4):27-31
最优分配采购策略和应急采购策略被广泛应用于供应中断风险管理中,基于最优分配采购策略和应急采购策略,研究了由两个制造商与两个零售商组成的两级供应链在供应中断下的订购和生产决策问题,给出了最优订购和最优生产策略.通过数值例子就可靠性如何影响制造商的最优价格和利润进行了比较. 结果表明：随着可靠性的增加,两个制造商的最优价格呈递减态势,且制造商A的递减幅度小于制造商B的递减幅度;当可靠性低于0.3时,制造商A的最优价格低于制造商B的最优价格,当可靠性高于0.3时,制造商A的最优价格高于制造商B的最优价格. 随着可靠性的增加,制造商A的利润呈递减态势,制造商B的利润呈递增态势;当可靠性低于0.8时,制造商A的利润高于制造商B的利润,当可靠性低高于0.8时,制造商A利润低于制造商B的利润. 相似文献
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姜辣素提取工艺及其对亚硝酸盐的清除作用研究 总被引：1，自引：0，他引：1
采用纤维素酶法辅助提取姜辣素,确定姜辣素最优提取工艺条件;将提取出的姜辣素用于清除亚硝酸盐,确定最优清除条件.结果表明,姜辣素最优提取工艺条件为酶添加量1.4％、料液比1:40、酶解温度65℃、酶解时间85 min,在该条件下平均提取率为2.61％;姜辣素清除亚硝酸盐的最优反应条件为添加5μg/mL亚硝酸钠溶液2.0 mL,姜辣素浓度15 mg/mL、反应温度80℃、反应时间20 min、姜辣素添加量4.5 mL,在该条件下平均清除率为98.74％. 相似文献
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Laufer H Borst D Baker FC Reuter CC Tsai LW Schooley DA Carrasco C Sinkus M 《Science (New York, N.Y.)》1987,235(4785):202-205
Juvenile hormone (JH) has central roles in the regulation of insect development and reproduction but has not previously been identified in other arthropod classes. The hemolymph of a crustacean, Libinia emarginata (Leach), has now been analyzed for JH-like compounds. Samples contained 0.003 to 0.030 nanogram of JH III per milliliter and 10 to 50 nanograms of methyl farnesoate per milliliter; methyl farnesoate is a compound structurally related to JH III that has JH bioactivity. Several tissues were examined for synthesis and secretion of JH-like compounds. Of these tissues, only the mandibular organs produced and secreted JH III and methyl farnesoate. However, microchemical analysis revealed that this JH III was racemic, and thus likely an artifactual oxidation product of methyl farnesoate. Secretion of methyl farnesoate was related to reproduction in females, with the highest rates observed in Libinia near the end of the ovarian cycle when oocyte growth and vitellogenesis are greatest. These results indicate that JH-like compounds such as methyl farnesoate have regulatory roles in crustaceans. 相似文献
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We report a method for compensating the birefringence of optical polymers by doping them with inorganic birefringent crystals. In this method, an inorganic birefringent material is chosen that has the opposite birefringence to that of the polymer and has rod-shaped crystals that are oriented when the polymer chains are oriented. The birefringence of the polymer is thus compensated by the opposing birefringence of the crystal. Birefringence is minimized in various polymer optical devices by adjusting process conditions, because it degrades the performance of devices. This method minimizes it, independent of process conditions, which potentially improves the productivity of devices. 相似文献
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Agriculture and Human Values - Greece's agricultural economy has undergone a gradual process of adjustment since World War II. While farm numbers have been reduced and average farm size has... 相似文献
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It has been suggested that Thaxteriola species and other minute, nonmycelial fungi associated with arthropods have phylogenetic relationships with the Laboulbeniales. However, direct development of the thallus of Thaxteriola from an ascospore of Pyxidiophora has now been discovered. Thaxteriola is specialized for dispersal by mites carried on pine bark beetles; other fungi dispersed by arthropods in this symbiotic assemblage rely primarily on arthropod specializations. 相似文献
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Viroid-induced phosphorylation of a host protein related to a dsRNA-dependent protein kinase 总被引：2，自引：0，他引：2
Viroids are very small, unencapsidated RNAs that replicate and induce severe disease in plants without encoding for any proteins. The mechanisms by which the viroid RNA regulates these events and interacts with host factors are unknown. An Mr 68,000 host-encoded protein has been identified that is differentially phosphorylated in extracts from viroid-infected and mock-inoculated tissues. This phosphoprotein is immunologically related to a double-stranded (ds) RNA-dependent protein kinase from virus-infected, interferon-treated human cells. Further, nucleotide photoaffinity labeling indicates that the protein has an ATP binding site. This protein is similar to dsRNA-dependent protein kinases implicated in mammalian systems in the regulation of protein synthesis and virus replication. 相似文献
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We describe a heptameric protein pore that has been engineered to accommodate two different cyclodextrin adapters simultaneously within the lumen of a transmembrane beta barrel. The volume between the adapters is a cavity of approximately 4400 cubic angstroms. Analysis of single-channel recordings reveals that individual charged organic molecules can be pulled into the cavity by an electrical potential. Once trapped, an organic molecule shuttles back and forth between the adapters for hundreds of milliseconds. Such self-assembling nanostructures are of interest for the fabrication of multianalyte sensors and could provide a means to control chemical reactions. 相似文献
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H Knoche G Ourisson G W Perold J Foussereau J Maleville 《Science (New York, N.Y.)》1969,166(902):239-240
Frullania spp. (Hepaticae, Jungermanniales) are agents of allergies. Extraction and fractionation of Frullania tamarisci has given, as the only allergenic component isolated, a levorotatory crystalline sutbstance, the structure of which is demonstrated. It is a sesquiterpene lactone. The racemic (+/-) form is isolated from a mixed sample of Frullania tamarisci and Frullania dilatata; the dextrorotatory form, from Frullania dilatata. The observed allergenic properties are shared by some other-sesquiterpene lactones. 相似文献
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采用PCR扩增的方法,得到AtPLC151 380 bp的启动子片段,构建了带动报告基因GUS表达的双元载体,转化拟南芥并筛选阳性转基因植株。通过组织化学染色分析AtPLC15基因在拟南芥中的表达情况,结果显示AtPLC15基因在拟南芥幼苗的子叶、下胚轴、根尖和柱头处有表达,在成熟花药中表达量极少,而在幼苗子叶和根尖中有极高的表达量。对该基因的功能有了新的认识,为阐述其功能机理提供了重要研究基础。 相似文献