Information revelation in sequential auctions with uncertainties about future objects

In many auctions, buyers know beforehand little about objects to be sold in the future. Whether and how to reveal information about future objects is an important decision problem for sellers. In this paper, two objects are sold sequentially and each buyer’s valuation for the second object is k times that for the first one, and the true value of k is sellers’ private information. The authors identify three factors which affect sellers’ revelation strategies: The market’s competition intensity which is characterized by the number of buyers, buyers’ prior information about the second object, and the difference degree between two objects which is characterized by k. The authors give not only conditions under which revealing information about the second object in advance benefits the seller, but also the optimal releasing amount of information in the market with two sellers and one seller, respectively.     

基于Petri网的直升机反潜仿真

Petri网对具有并行、异步和随机时间的离散事件仿真系统具有很强的可视化描述能力,它可以通过标记在网内的流动揭示系统的动态行为。而直升机反潜过程是一个复杂的离散事件过程,包括了搜索、跟踪、定位和攻击四个阶段,各阶段之间的转换是由各种战术规则和随机战场态势所决定的,具有并行、异步和冲突竞争等特点,采用传统的排队论和决策树方法描述直升机反潜过程非常困难。在建立了描述这些过程的Petri网的基础上,提出了处理并行和竞争变迁的实施原则,实现了直升机反潜过程描述的可视化。     

分数阶反向累加Verhulst模型

本文提出采用反向累加的方式对原始数据进行处理,并在整数阶的基础上将其推广到分数阶领域,以分数阶反向累加生成算子和分数阶反向累减生成算子为基础,建立分数阶反向累加Verhulst模型,并应用实例与分数阶反向累加GM(1,1)模型作对比,检验模型模拟误差.相关结果显示,相较于传统Verhulst模型与分数阶反向累加GM(1,1)模型,分数阶反向累加Verhulst模型的数据拟合精度较高.     

Dλ——圈图成为Hamilton图的两个充分条件

在本文中,我们引入了下面两个新的概念：λ－最小度δλ,λ－独立数αλ,用这两个参数,给出了Ｄλ－圈图成为Ｈａｍｉｌｔｏｎ图的两个新的充分条件。     

高校思想政治教育科研的战略性思考

高校思想政治教育的受教育者崇尚科学,崇尚理性,因此,科研是思想政治教育教学质量好坏的决定性因素,但反思高校思想政治教育科研,在科研定位,科研队伍建设、科研体制等战略性问题上存在偏差。正确解决这些战略性问题,才能推进高校思想政治教育科研发展,从而促进高校思想政治教育教学。     

Is the maximum carbon number of long-chain <Emphasis Type=Italic>n</Emphasis>-alkanes an indicator of grassland or forest? Evidence from surface soils and modern plants

The molecular distribution of long-chain n-alkanes in 62 soil samples collected from diverse locations across eastern China was analyzed.The long-chain n-alkanes were mostly dominated by n-C29 or n-C31,regardless of the overlying vegetation type at each site.The results were compared with those summarized from the literature,covering more than 100 soil samples within China and more than 300 genera of modern plants distributed worldwide.There were similar n-alkane distribution patterns for most genera, with no clear differences among grasses,shrubs,and trees.The evidence from analyses of surface soils and modern plants indicates that the relationship between the molecular distribution of long-chain n-alkanes of surface soils and source vegetation is highly complex,and is influenced by many factors.Further,it is suggested that source vegetation types should not be simply inferred from distribution patterns of long-chain n-alkanes in sediments.     

读苏霍姆林斯基《让少年一代健康成长》札记

本文对苏霍姆林斯基《让少年一代健康成长》所论的有关少年教育问题进行了教育学分析,认为苏霍姆林斯基的少年教育思想对当前我国正在进行的素质教育有积极的借鉴作用。     

C_(60)羟基化合物的纯化

采用３种不同的分离提纯方法（即离子交换隔膜电渗析法，离子交换法，凝胶色谱柱法）对Ｃ６０羟基化合物Ｃ６０（ＯＨ）ｎ的纯化进行研究．结果表明，随着杂质阳离子Ｎａ＋和Ｂｕ４Ｎ＋的脱除，该化合物的结构发生变化，出现酮式结构．作者通过分析该结构变化的过程发现，Ｃ６０羟基化合物结构不稳定，一般以醇盐或酮的形式稳定存在，且Ｃ６０羟基化合物纯化难以实现     

Vaccine protection against acquisition of neutralization-resistant SIV challenges in rhesus monkeys

Preclinical studies of human immunodeficiency virus type 1 (HIV-1) vaccine candidates have typically shown post-infection virological control, but protection against acquisition of infection has previously only been reported against neutralization-sensitive virus challenges. Here we demonstrate vaccine protection against acquisition of fully heterologous, neutralization-resistant simian immunodeficiency virus (SIV) challenges in rhesus monkeys. Adenovirus/poxvirus and adenovirus/adenovirus-vector-based vaccines expressing SIV(SME543) Gag, Pol and Env antigens resulted in an 80% or greater reduction in the per-exposure probability of infection against repetitive, intrarectal SIV(MAC251) challenges in rhesus monkeys. Protection against acquisition of infection showed distinct immunological correlates compared with post-infection virological control and required the inclusion of Env in the vaccine regimen. These data demonstrate the proof-of-concept that optimized HIV-1 vaccine candidates can block acquisition of stringent, heterologous, neutralization-resistant virus challenges in rhesus monkeys.