Fast liquid chromatography–quadrupole-linear ion trap mass spectrometry for the analysis of pharmaceuticals and hormones in water resources

This paper presents the development of a fast multi-residue method for the determination of 49 pharmaceuticals and 6 metabolites from different therapeutic classes in water resources by means of Ultra-performance™ liquid chromatography (UPLC) coupled to tandem mass spectrometry. The use of the UPLC technology enabled all the 55 compounds to be separated chromatographically in less than 9 min (6.3 min positive mode and 2.7 min negative mode) and with a total analysis time of 18 min when considering column conditioning. Improved resolution, sensitivity and a reduction of matrix effects were obtained under these conditions. Unequivocal identification and quantification of the target compounds was also performed by using the dual acquisition modes of the hybrid triple quadrupole-linear ion trap (QqLIT) system. Triple quadrupole mode by means of selected reaction monitoring (SRM) was used for quantification, whilst a second SRM transition together with information-dependent analysis (IDA) experiments was used for confirmation. Additionally, one general, single solid-phase extraction (SPE) method was developed by using Oasis HLB cartridges. Quality parameters of the method in wastewaters were established obtaining a fast, robust, reproducible and cost-effective method for all the target pharmaceuticals. Finally, the optimized SPE-UPLC/QqLIT method was used for the analysis of the target compounds in wastewaters from Spain. Thirty-one out of fifty-five compounds were identified in the samples collected.     

人寿保险中有关赔率和风险的若干讨论

本文讨论了保险业务中的赔率、盈利率、参加保险人数和风险系数等指标的依赖关系 ,证明了极限赔率与风险系数无关     

具有限制结盟结构的供应链合作创新及其收益分配

针对具有限制结盟结构特征的三级供应链合作创新联盟问题,分析了由单个供应商、制造商和销售商组成的不同联盟系统下的收益情况,并运用图合作博弈的average tree solution(简称“A-T解”)法对各成员的收益进行了分配。结果表明,所有成员参与供应链联盟时总收益最大,且A-T解分配法与Shapley值法相比更具合理性和有效性,能充分突出成员在合作联盟中的特殊地位(位置)及其重要性,该结论进一步通过比较不同级别结构下的供应链收益分配问题进行说明。     

需求受库存影响下具有固定保质期物品的最优订货策略

带有固定保质期物品的订货是供应链终端销售系统的一个重要决策问题,假设需求依赖库存展示水平并考虑"后进先出"的销售策略而建立了相应的库存决策模型,其中物品在固定保质期内仍具有常数的变质速率.然后以系统平均利润最大化为目标讨论了模型最优解的存在性及唯一性,并提供了寻求模型整体最优解的简单方法.最后给出应用实例,并分析了模型参数变化对最优订货策略的影响.     

基于区间shapley值的中小企业融资联盟利益分配

融资联盟是一种新型的中小企业融资模式,结合中小企业融资联盟预期收益不确定的特点,运用区间shapley值法进行企业间的利益分配,引入联盟企业的风险因子和融资成本,改进后的利益分配方式更具合理性和可行性,有利于维护融资联盟的长期稳定.     

上海市国际服务贸易收入和支出的统计分析

本文通过因子分析将指标进行分类,对2000-2007年上海市国际服务贸易收入和支出的数据进行统计分析。同时,通过回归分析从理论上提出对国际服务贸易收入和支出的预报和控制方法。最后对文章中提到的模型进行使用说明,并提出对上海市国际服务贸易发展的一些建议。     

三级供应链合作利润博弈与分配机制构建

基于变形需求函数建立了多向主从式三级供应链下游成员合作利润博弈模型,运用Stackelberg博弈法求解,对成员及渠道利润随合作关系程度变化进行深入的经济分析;构建了具有理性、转移性、协商性的供应链下游合作利润分配机制定量模型,其由合作利润结构性分配和合作利润运行性分配组成,阐明了之间的互动关系与内在运行方式,得出当合作关系程度高于2/3时才进行合作利润运行性分配的结论,且对分配机制的内在运行方式进行了数学解析。     

考虑互惠偏好的闭环供应链系统合作机制研究

将互惠偏好引入到闭环供应链系统合作机制中,研究了由一个制造商,一个零售商和一个再制造商组成的三层闭环供应链,运用Stackelberg博弈理论分析了闭环供应链整体及各成员的最优决策问题,并对5种情形(决策模式)下的均衡结果进行比较分析.研究发现在考虑互惠偏好行为下,分散决策模式和局部联盟决策模式下的系统利润低于集中决策模式下的收益;新产品和再制造产品的销售量(零售价格)与制造商对零售商的互惠偏好系数呈正(负)相关,与零售商对制造商的互惠偏好系数呈负(正)相关;5种决策模式的供应链系统利润与制造商对零售商的互惠偏好系数呈正相关,与零售商对制造商的互惠偏好系数呈负相关.     

The volume and foundation of star trades

An x-star trade consists of two disjoint decompositions of some simple graph H into copies of K_1,x, the graph known as the x-star. The number of vertices of H is referred to as the foundation of the trade, while the number of copies of K_1,x in each of the decompositions is called the volume of the trade. We determine all values of x, v and s for which there exists a K_1,x-trade of volume s and foundation v.     

The EU regulation on cross-border trade of electricity: A two-stage equilibrium model

The regulation on cross-border exchanges of electricity in the European Union is meant to enhance the trade of electricity between Member States, by facilitating access to the network and improving the management of congestion at the interconnections. This paper presents a computational model that embeds these two features. The problem is cast in the form of a two-stage equilibrium between regional Regulators. In the first stage, they decide on the allocation of their regional network costs between generators and customers. Either they maximise their regional welfare non-cooperatively (Nash equilibrium), or they centralise the decision as a super-regulator (leading to a cooperative equilibrium). In the second-stage equilibrium, the consequences of first-stage’s decisions are assessed by modelling the energy market as the result of imperfect competition equilibrium on competitive market, coupled with regulated pricing on the domestic less competitive markets. The “rules” that come out of the first-stage game largely influence the final equilibrium. We illustrate this on an extensive numerical example, showing that the model behaves properly and identifying policy issues worth of further investigations.