基于在线评价信息的概率语言多属性变权决策方法

针对电子商务网站中涌现的大量在线评价信息,本文提出一种基于在线评价信息的概率语言多属性变权决策方法,指导消费者的购买决策。在本文方法中,首先利用概率语言描述在线评价信息,构建概率语言决策矩阵,并重新定义了区间概率语言的得分函数;其次,利用变权方法处理决策矩阵,得出不同方案的各属性权重;再次,依据得出的属性权重,基于后悔理论,考虑决策者风险规避系数,求出各方案的综合感知效用值,并据此排序。最后,利用汽车之家网站提供的顾客在线评价信息,以一个汽车选择的实例说明了本文所提方法的合理性与实用性。     

心理帐户视角下基于电子优惠券的零售商渠道整合策略——以“优衣库”为例

当前, 零售商的渠道策略从以往各自为政的经营模式转向于关注渠道整合程度。越来越多的零售商开始通过为搜索产品中的线上消费者提供电子优惠券, 以此吸引其转移到线下渠道购买产品。本文基于对“优衣库”渠道整合案例的梳理, 引入心理账户收入幻觉, 建立了不同渠道策略下两个零售商之间的Hotelling模型。研究发现电子优惠券能够实现消费者从线上向线下渠道的转移, 零售商在一定条件下能够借此扩大市场规模并获利。此外, 优惠券策略受消费者到店产生的额外购买给零售商带来的收益的影响。同时, 消费者心理账户形成的收入幻觉、消费者对线上渠道的偏好异质性也影响优惠券策略。     

保险动态惩罚机制对网约车平台监督作用的演化博弈研究

采用演化博弈方法,研究保险公司与网约车平台之间的博弈演化过程,分析了在保险公司监督下,网约车平台策略选择的影响因素,并比较了静态惩罚机制和动态惩罚机制下网约车平台与保险公司博弈的均衡策略。研究发现,保险公司的惩罚性保费可以促使网约车平台的策略选择发生改变。在静态惩罚机制下,网约车平台和保险公司的策略选择呈周期波动模式,不能收敛;在动态惩罚机制下,网约车平台和保险公司的博弈呈现螺旋收敛的演化轨迹,且收敛的均衡点不随策略选择的初始概率不同而改变。研究结论明确了保险在网约车行业管理中的社会监督职能,并为保险公司保费的制定提供理论参考。     

基于排序预测的带交易费用在线投资组合策略

在线投资组合决策过程中频繁调整资产头寸会产生较多的交易费用。本文提出了一个综合考虑预期收益和交易费用的在线投资组合策略。通过预测资产的排序计算组合的预期收益,利用相对熵距离衡量交易费用,构造了一个极大化预期收益和极小化交易费用的优化模型,从而得到了一个在线投资组合更新策略。然后,从理论上证明了该策略具有BH泛证券性,即该策略与离线的最优购买并持有策略具有相同的渐近平均指数收益率。最后,采用中美股票市场实际数据,对该策略进行了数值分析。结果表明,该策略的表现优于已有的在线投资组合策略,且对模型的参数不敏感。     

Application of Covalent Organic Porous Polymers-Functionalized Basalt Fibers for in-Tube Solid-Phase Microextraction

To establish an online analytical method towards estrogenic pollutants, a covalent organic porous polymer (COP) was in-situ synthesized on the surface of basalt fibers (BFs) for in-tube solid-phase microextraction (IT-SPME). The extraction tube, obtained via placing the modified BFs into a polyetheretherketone tube, was combined with high-performance liquid chromatography (HPLC) to achieve online IT-SPME-HPLC analysis. The important parameters, including sampling volume, sampling rate, organic solvent content and desorption time, were carefully investigated. Under the optimized conditions, the online analytical method was established for five estrogenic targets, with low limits of detection (0.001–0.005 μg/L), high enrichment factors (1800–2493), wide linear ranges (0.003–20, 0.015–20 μg/L) and satisfactory repeatability. It was successfully applied to detect five estrogens in a wastewater sample and a water sample in a polycarbonate cup. The BFs functionalized with COPs displayed excellent extraction effect for estrogenic pollutants, furthermore it has great potential in sample preparation or other fields.     

用于人血浆中蛋白质分离的在线阵列式二维常规柱液相色谱系统的建立

构建了一种在线阵列式二维常规柱液相色谱系统,并将其应用于分离血浆中的完整蛋白质。该系统以1根强阴离子交换柱作为第一维分离柱,8根阵列式反相色谱柱作为第二维分离柱。强阴离子交换柱分离的馏分通过十通阀被依次转移到第二维预柱上并得到保留富集,随后第二维流动相通过分流器同时将预柱上的蛋白质反冲至分析柱上进行分离。二维之间以及第二维阵列色谱柱之间均相互独立,从而可以提高系统分离的通量和总峰容量。采用该系统对血浆中的蛋白质进行了完整蛋白质水平上的分离。该系统具有高通量和高分辨率的特点,为血浆样品中高丰度蛋白质的去除以及血浆样品的深入研究提供了一种有效的手段。     

销售商出售看跌期权的供应链优化研究

在由一个供应商和一个销售商组成的单期两级供应链中,处于主导地位的销售商以其卖场所具有的销售能力参与供应链合作,并从销售的每一个产品中获取既定收益。同时,销售商还向供应商出售建立在产品销售量保障基础上的看跌期权,以激励供应商参与供应链合作。论文对上述情形的销售商出售看跌期权的供应链合作问题进行了研究,通过建模与优化分析,证明了在销售商提供看跌期权的供应链合作中,供应商存在唯一的最优生产批量和看跌期权采购量,以及销售商存在最优的从每一单位产品销售中获取的既定收益。论文还揭示了销售商提供看跌期权,虽然无法实现供应链协调,但可以实现供应链参与企业所获得的收益与其所承担的风险相匹配。最后,论文论证了在销售商出售看跌期权机制下,供应链存在收益损失较小的理想合作区域。     

中国第一组超导电缆并网运行试验

中国第一组超导电缆于2004年4月19日在昆明普吉220kV变电站并网成功，并开始向用户供电．本文详细地描述了该电缆并网前后部分试验，如：超导电缆直流电阻测量、超导电缆通流试验、温度、压力和流量的在线监测、绝缘电阻和介损损耗测试等．所有试验结果均显示该电缆技术指标达到实际并网运行要求．超导电缆并网运行成功，标志着我国已经掌握了超导电缆开发能力．本文所提出的超导电缆并网运行试验方法和试验结果为我国进一步开发超导电缆提供了宝贵的经验．     

Screening of antioxidant activity and volatile compounds composition of Chamerion angustifolium (L.) Holub ecotypes grown in Lithuania

Since biological activity of medicinal plants is dependent on cultivation area, climatic conditions, developmental stage, genetic modifications and other factors, it is important to study flora present in different growing sites and geographical zones. This study was focused on screening of antioxidant activity of C. angustifolium harvested in six different locations in Lithuania. The total contents of phenolic compounds, flavonoids and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity were evaluated by spectrophotometric methods. A correlation between radical scavenging activity and total phenolic compounds content was observed (correlation coefficient 0.98). HPLC with online post-column DPPH radical scavenging reaction detection was used for the separation of extracts. Oenothein B, rutin and one unidentified compound were predominant. Volatile compounds were analysed using solid-phase microextraction coupled with gas chromatography–mass spectrometry. Based on the analysis of volatiles, all samples were classified into two chemotypes: (I) with predominant α- and β-caryophyllenes and (II) with predominant anethole.     

A semi‐quantitative approach for the rapid screening and mass profiling of naphthenic acids directly in contaminated aqueous samples

We report the use of a direct sampling, online analytical approach for the determination of acid extractable naphthenic acids in complex aqueous samples, known as condensed phase membrane introduction mass spectrometry (CP‐MIMS). The technique employs a capillary hollow fibre semi‐permeable membrane probe configured for immersion into a pH adjusted sample. A continuously flowing methanol acceptor phase transfers naphthenic acids to an electrospray ionization source, operated in negative ion mode, whereupon they are analysed by mass spectrometry as [M–H]^? ions. High‐resolution mass spectrometry is used to characterize the influence of sample pH on membrane transport of multiple components of complex naphthenic acid mixtures. We demonstrate the use of CP‐MIMS for semi‐quantitative analysis of real‐world samples using selected ion monitoring and full scan mass spectra at unit mass resolution. The technique has also been employed to continuously monitor the temporal evolution in the mass profile and concentrations of individual naphthenic acid isomer classes in heterogeneous solutions during adsorption processes. Copyright © 2015 John Wiley & Sons, Ltd.