基于多实例的图书采购辅助决策模型

针对图书采购工作中待选图书受欢迎程度的预测问题，设计了一种基于多图书实例预测的方案，并给出了参照图书集模型的表示法，以及待选图书与参照图书集之间相似度的计算公式，在此基础上，提出了结合图书重要性和资金约束因素的图书采购多目标辅助决策模型。     

基于不同参考框架的GPS卫星天线校验

重新估计了基于不同参考框架的GPS卫星天线PCO(相位中心偏差)和PCV(相位中心变化)参数.计算过程中,通过固定测站天线的PCO和PCV,并将测站坐标强约束至不同的参考框架之下,降低了GPS卫星天线参数和接收机天线参数以及参考框架参数之间的相关性.结果显示,基于不同参考框架的同类型卫星天线PCV差异的平均值为0.726mm;与IGS发布值差异的平均值为0.844mm;基于新公布的IGS14参考框架的GPS卫星天线PCO估计结果与IGS(国际GNSS服务)发布值差异的平均值为-14.4mm,基于IGb08参考框架的卫星天线PCO估计结果与IGS发布值差异的平均值为-16.8 mm.以上结果表明,本措施提高了GPS卫星相位中心PCO/PCV的一致性,从而也能提高GNSS(global navigation satellite system)技术用于框架传递的连续性.     

全球参考站网窄巷非校准相位延迟

窄巷非校准相位延迟（UPD）产品的质量和可用性是影响精密单点定位模糊度固定（PPPAR）效率的重要因素.采用全球108个国际GPS服务（International GPS Service,IGS）测站观测数据,计算了基于全球参考站网的窄巷UPD产品,分析了窄巷UPD产品的变化特性,其单日变化量最大可达0.6周.通过分析UPD改正后的模糊度残差,论证了UPD产品和用户端模糊度均受到因未被恰当模型化而造成的残余误差的影响,且UPD的时变特性与各参考站残余系统误差有关.最后,采用4个用户站进行PPPAR实验分析UPD产品的可用性,以模糊度固定失败率、固定错误率和首次固定时间为评估指标,结果表明,全球参考站网窄巷UPD产品的最佳使用时限不大于30 min.     

Trifluoroethylxanthate as an Analytical Reagent: AAS of Zinc,Antimony and Lead After Coprecipitation of Their Trifluoroethylxanthates onto Microcyrstalline Naphthalene

Abstract

A sensitive method has been developed for the direct atomic absorption spectrometric determination of zinc, antimony and lead after coprecipitation of their trifluoroethylxanthates onto microcrystalline naphthalene. The metal xanthates are quantitatively coprecipitated over the pH ranges: Zn, 5.9–8.4; Sb, 4.0–6.0 and Pb, 4.0–11.0. The solid mass consisting of the metal complex and naphthalene is dissolved in DMF. This solution is aspirated into an air-acetylene flame at 213.9, 217.6 and 217.0nm for Zn, Sb and Pb, respectively. Beer's law is obeyed in the concentration range 2–50, 3–90 and 5–60 μg of Zn, Sb and Pb, respectively in 10ml of the final DMF solution. RSDs are at the ± (0.5–0.6)% level (n=10). The concentration for 1% absorption is 0.019, 0.035 and 0.060μg/ml for Zn, Sb and Pb, respectively. The method is suitable for the preconcentration of the metals from a larger volume of the aqueous phase, and has been employed for their determination in standard reference materials. It may be employed for the simultaneous determination of Zn, Pb and Sb in a solution by pH control.     

A dynamic process interpretation of the sparse ERGM reference model

Exponential family random graph models (ERGMs) can be understood in terms of a set of structural biases that act on an underlying reference distribution. This distribution determines many aspects of the behavior and interpretation of the ERGM families incorporating it. One important innovation in this area has been the development of an ERGM reference model that produces realistic behavior when generalized to sparse networks of varying sizes. Here, we show that this model can be derived from a latent dynamic process in which tie formation takes place within small local settings between which individuals move. This derivation provides one possible micro-process interpretation of the sparse ERGM reference model and sheds light on the conditions under which constant mean degree scaling can emerge.     

高校历史院系资料室文献资源建设探讨——以山东大学历史文化学院为例

论述了高校历史院系资料室的藏书必须以原始资料为主的重要性,概述了高校历史院系资料室的藏书重点,提出了高校历史院系资料室的藏书原则。     

关于民办院校图书馆开展定题服务的思考

阐述了民办院校开展图书馆定题服务的必要性,指出民办院校图书馆具备开展定题服务的条件,探讨了民办院校图书馆开展定题服务的原则,展望了民办院校图书馆开展定题服务的前景。     

论中国梦视域下近代华侨华人爱国的精神动力

在鸦片战争中,西方资本-帝国主义用坚船利炮打败了闭关锁国的清政府。面对祖国惨遭西方列强的侵略、杀戮、掠夺,近代海外华侨华人与国内同胞一样,以坚强不屈、百折不挠的精神书写了抗争外国侵略的悲壮历史。孕育与激励海外华人爱国情怀的精神动力不仅有着深刻的时代背景,同时还根源于中华民族的历史文化。"振兴中华"是近代海外华人孜孜以求之的强国梦。鉴往知来,新时期重温华侨爱国精神对于当代大学生践行"中国梦"的时代使命和弘扬爱国主义主旋律有着重要意义。     

浅谈网络环境下高校图书馆如何改进参考咨询服务

通过对网络环境下参考咨询服务与传统参考咨询服务的比较,阐述了现代高校图书馆参考咨询服务的特点、现状及存在的问题,并对如何提高参考咨询服务水平提出了一些见解。