"花瓶"一无所用?独立董事对公司创业导向的影响

近年来,创业导向前因研究的焦点已渐从外部环境转至企业及管理者层面.其中有关管理者层面的因素涉及董事会整体和CEO,鲜有研究考察其他类别董事(如独立董事)对创业导向的影响.基于此,文章整合合法性理论与信号理论,预测和检验独立董事与创业导向的关系.基于信息传输、软件和信息技术服务业A股上市公司2011—2016年的面板数据,实证结果表明,独立董事的存在通过增加企业合法性促进创业导向,当独立董事中存在"学者董事"时,上述关系的强度增强;而企业所在地区制度发展水平较高时,上述关系的强度减弱.文章具有一定的理论和实践意义.     

Effects of Power Inversion Spatial Only Adaptive Array on GNSS Receiver Measurements

The Spatial Only Processing Power Inversion(SOP-PI) algorithm is frequently used in Global Navigation Satellite System(GNSS) adaptive array receivers for interference mitigation because of its simplicity of implementation. This study investigates the effects of SOP-PI on receiver measurements for high-precision applications. Mathematical deductions show that if an array with a centro-symmetrical geometry is used, ideally,SOP-PI is naturally bias-free; however, this no longer stands when non-ideal factors, including array perturbations and finite-sample effect, are added. Simulations are performed herein to investigate how exactly the array perturbations affect the carrier phase biases, while diagonal loading and forward-backward averaging are proposed to counter the finite-sample effect. In conclusion, whether SOP-PI with a centro-symmetrical array geometry will satisfy the high precision demands mainly depends on the array perturbation degree of the element amplitude and the phase center.     

Breeding preferences in the treefrogs Dryophytes japonicus (Hylidae) in Mongolia

ABSTRACT

When a species occurs over a broad range of climates and landscapes, the breeding ecology of that species is expected to vary locally. Additionally, a basic knowledge of breeding ecology is required before other types of studies may be conducted, such as physiology or conservation. In North East Asia, Dryophytes japonicus is distributed from Japan to Mongolia, where its breeding ecology is unknown. The objectives of this study were to understand the breeding requirements of D. japonicus in this part of its range. We collected data for Dryophytes japonicus at 56 sites located within 23 independent localities in Northern Mongolia during the breeding season 2017. The data collected included habitat type and co-occurring amphibian, fishes and bird species. Our results show that the species prefers circa 70 m long oxbow lakes for breeding, while habitat characteristics, water quality and co-occurring species were not significantly associated with the occurrence of the species. We therefore conclude that D. japonicus is behaviourally plastic in Mongolia, as it is in other portions of its range, and that the species can use several types of environments and co-occur with different species at its breeding sites. Corvus dauuricus was the only bird species significant predicting the occurrence of D. japonicus, likely because of overlapping ecological preferences.     

毛花猕猴桃果实发育过程中理化性质的变化研究

为深入了解猕猴桃果实生长发育规律及果实商品价值,本研究以四川地区野生毛花猕猴桃果实为材料,采用田间取样和实验室测定相结合的方法测定其果实发育过程中理化性质变化.结果显示果实重量、纵横径和干物质积累呈单‘S’型曲线.果实淀粉积累时间短,果糖和葡萄糖从盛花期(DAA)105 d开始急剧上升,果实成熟时生成少量的蔗糖和麦芽糖.苹果酸和柠檬酸浓度整体呈上升趋势,而奎宁酸在90 DAA前保持相对恒定,105 DAA时下降到最低,后保持稳定.VC含量高,整体呈下降趋势.以上结果说明毛花猕猴桃果树园艺性状好,其果实有机酸含量高,特别是VC,是天然维生素库.     

共享经济赋能科技型小微企业成长的效应研究

共享经济是基于信息技术实现分散、闲置资源优化配置的新经济形态,拓宽了企业可利用资源范围,为解决科技型小微企业成长的资源约束提供了可能。本文引入赋能的概念,探讨共享经济对科技型小微企业成长的影响机理,并通过实证方法进一步检验其作用效应。结果表明,共享经济通过赋能技术、人才、金融、产能等,可缓解科技型小微企业成长过程中资源约束,有助于科技型小微企业实现"小而美"的成长。     

流行词“吃货”的多角度考察

"吃货"最早出现在清代小说中,指光吃不干活的人,带有贬义色彩。近年来,"吃货"一词被广大美食爱好者广泛传播,用于自称和互称。"吃货"一词的词义已发生明显变化,指"喜欢吃各类美食的人,有品位的美食爱好者";词义附带的感情色彩逐渐趋于中性甚至褒义。而导致这些变化的原因主要是人们对"吃"观念的改变,网络语言环境的高度自由化以及使用网络语言的从众心理。     

突发事件快速评估模型

突发事件发生初期,进行突发事件的快速综合评估,有利于及时、准确地把握事件的态势,以满足应急决策的时效性要求.为解决突发事件数据量较大,数据更新较快时,过于复杂的运算过程和计算软件缺乏以及已有软件兼容性低而难以满足应急决策的时效性要求的问题,本文简化了Simos过程和PROMETHEEⅡ方法,构建了突发事件快速评估模型,即SSPPM(Simple Simos'Procedure and PROMETHEEⅡModel).为了验证新模型的有效性,本文选取了两个数据进行实验.实验结果表明,在对评估速度的要求大于对精度的要求的突发事件控制阶段,新模型能快速综合多位应急决策者的意见,快速获取权重,简化评估过程,提高突发事件综合评估效率.     

PRICE AND SERVICE COMPETITION WITH MAINTENANCE SERVICE BUNDLING

In many equipment manufacturing industries,firms compete with each other not only on products price,but also on maintenance service.More and more traditional products oriented firms are offering their customers products bundled with maintenance service(P&S bundles).In this study,we examine firms’ incentive to offer customers products bundling with long-term maintenance or repair support service in a duopoly competitive environment.When providing P&S bundles,a firm need to determine the service level(in terms of average response time guarantee for the service in this paper) to offer and needs to build a service facility to handle the maintenance service requirements.Based on the analysis of three sub-game models,we characterize the market conditions in which only one firm,both firms or neither firm will offer P&S bundles.Finally,we analyze the affects of serval market factors on firms’ strategy choices.     

基于因子分析的农村中学生体质的因素分析

中学生中农村人口占较大部分,他们的体质影响着未来我国人口的整体状况.对随机抽样的1 724名农村中学生进行调查,采用数理统计法和实验法,对具有重要影响的16个子因素进行因子分析,认为在生活方式、家庭和学校等3个方面对农村中学生的体质起着决定作用.对这3个方面的改善给出了建议,为学校体育在提高和改善农村中学生体质科学研究方面提供理论依据.