高速铁路桩板结构承载板伸缩温度力研究

以某高速铁路桩板结构路基工程为背景，研究了桩板结构路基单联跨数对承载板体伸缩温度应力的影响规律，提出了桩板结构的结构布置原则；并根据桩板结构路基具体结构特征，推导了计算结构整体升降温引起的承载板体伸缩温度应力计算公式，该解析式与空间有限元法计算结果较好吻合，可方便地计算承载板的伸缩温度应力。     

A dynamic product quality evaluation based pricing model for perishable food supply chains

Waste stemmed from inappropriate quality control and excessive inventories is a major challenge for perishable food management in grocery retail chains. Improvement of visibility and traceability in food supply chains facilitated by tracking and tracing technologies has great potential to improve operations efficiency. This research aims to reduce food spoilage waste and maximise food retailer's profit through a pricing approach based on dynamically identified food shelf life. The proposed model is evaluated through different pricing policies to exploit the benefits from utilising accurate product shelf life information captured through innovated tracking and monitoring technologies. Numerical analysis is conducted in an illustrative case study.     

基于改进模糊聚类算法的灰色预测模型

目前研究的模糊C均值聚类算法(FCM)面临的最重要问题是初始值随机选取,导致其容易陷入局部最优,同时影响运算速度.而灰色预测GM(1,1)模型在形成预测公式时对初始值的选取也没有合理有效的方案.针对以上问题,文章提出坐标密度法,确定初始聚类中心,对FCM算法进行改进;接着提出运用改进的FCM求取GM(1,1)中数据的聚类中心,并把聚类中心作为初始值的方法;通过与已知算法进行比较验证了其可行性和有效性.     

食品全产业链三维风险评价

为了有效控制食品全产业链风险,降低食品安全事件发生概率和影响程度,文章运用三维风险分析模型构建食品全产业链风险评价模型.从全产业链流程视角分析食品全产业链的各环节风险,从而构建食品全产业链风险评价指标体系.然后,采用熵值法确定食品全产业链风险评价指标重要度,结合现有食品全产业链风险发生可能性统计资料和风险后果划分标准,确定食品全产业链的各环节风险影响因素风险程度.根据风险发生概率、风险指标重要度和风险因素发生后果三维风险评价模型确定的关键因素,寻求相应的食品安全风险控制措施.     

Depletion Effect of Work-Leisure Conflict: A Daily Diary Study

The negative effect of work-leisure conflict has attracted the attention of researchers. However, no previous research has determined the relationship between work-leisure conflict and ego depletion. Therefore, this study explores the relationship between daily work-leisure conflict and ego depletion, as well as the role of individuals’ negative emotions and core self-evaluations in this process based on ego depletion theory. Through the method of daily diary research, 77 employees were tracked for 7 consecutive work days. The results show that work-leisure conflict is positively related to employee ego depletion, that the negative emotions play a mediating role in this relationship and that core self-evaluations moderate the indirect effect of work-leisure conflict on ego depletion through negative emotions. In this study, daily diary method is used to verify the dynamic characteristics of work-leisure conflict, negative emotions and ego depletion, and some new insights into how to reduce employee ego depletion are provided.

     

对冲与制衡:日本“印太战略”的地缘政治逻辑与制约因素

日本“印太战略”是依据日本在当前国际格局中的地位和地缘政治现实制定的,目的是对冲和制衡中国在印太地区影响的扩展,以维护当前有利于日本的国际秩序,进而实现维护日本的国家利益。日本“印太战略”在政治和安全领域主要依托“四国安全对话机制”,以构建地区同盟架构的方式,逐步实现日本的地缘战略。这既是当前东亚地缘政治的现实,也是日本作为海洋型国家的战略选择。但是,由于合作国家的战略偏好和地缘利益的差异以及中国周边外交的成功实施,特别是国际格局演变的趋势,从不同的层面制约日本“印太战略”的实施。日本“印太战略”是一项综合性战略,是对中国“一带一路”倡议的针对性措施,对中国地区利益的影响较为广泛,中国应从战略上予以重视。     

Feature screening in ultrahigh-dimensional additive Cox model

The additive Cox model is flexible and powerful for modelling the dynamic changes of regression coefficients in the survival analysis. This paper is concerned with feature screening for the additive Cox model with ultrahigh-dimensional covariates. The proposed screening procedure can effectively identify active predictors. That is, with probability tending to one, the selected variable set includes the actual active predictors. In order to carry out the proposed procedure, we propose an effective algorithm and establish the ascent property of the proposed algorithm. We further prove that the proposed procedure possesses the sure screening property. Furthermore, we examine the finite sample performance of the proposed procedure via Monte Carlo simulations, and illustrate the proposed procedure by a real data example.     

Educational gradient of health in rural China

The aim of this paper is to examine whether and how rural residents’ educational attainment is associated with their self-rated health in China. Taking advantage of the National Exercise Facility Survey that was collected between December 2015 and March 2016, we find that educational attainment has a significant and positive correlation with self-rated health, net of the effects of age, gender, and geographical region. This correlation is mediated by factors such as perceived importance of exercise and healthy lifestyle. Relatively, people’s cognitive knowledge about health-related information and material resource access fail to play a significant mediating role. The findings highlight the non-material and non-cognitive attributes of educational attainment in shaping the gradient of health in the rural setting of China. Interventions that expand formal education to the mass and optimize teaching contents may offer an effective means to balance the health gradient.     

中国基层社会治理政策变迁:演化、特征与经验——基于1978-2019年国务院政策文本分析

基层社会治理是国家治理体系的重要基础,中国基层社会治理政策随着经济社会发展在国家治理体系变迁中逐渐形成了独特的治理方略和中国经验。基层社会治理政策涉及的领域众多,为准确提炼出其核心内容,本文基于文献关键词的主题聚类结果,选取改革开放以来国务院关于基层社会治理的政策文本,通过发文时间、类型分布等计量分析中国基层社会治理政策变迁总体脉络。运用NLPIR汉语分词系统对政策标题进行文本深度挖掘,根据政策热点主题和政策变迁趋势等,将中国基层社会治理政策演化分为恢复重建阶段、宏观调控阶段、重心转移阶段和系统推进阶段。基于多源流理论探析政策变迁中问题源流、政治源流与政策源流的耦合特征,发现中国基层社会治理政策从形式、动力、主体和目标四个层面逐渐形成了突发性变迁与渐进性变迁并存、内生性驱动和外在性拉动结合、党依法执政与政府依法行政共同推进、坚持以人民为中心和问题为导向创新的中国经验,为发挥中国基层社会治理的政策优势提供有益借鉴。     

The disaster relief and social work after the Wenchuan earthquake in Mainland China

ABSTRACT

This paper mainly focuses on the development of disaster social work in Mainland China and the intervention of social work in disaster relief. Before the Wenchuan earthquake and in the initial stage of post-earthquake, disaster social work was mainly based on individual psychotherapy; from the earthquake to the year of 2012 in which post-earthquake recovery and reconstruction was completed, the disaster relief began to emphasise community building and integration, while the basic framework for disaster social work was also established. Social workers begin to explore the new mode of developmental and localised disaster social work. By combining with the practical experiences from disaster social work, this paper tries to highlight the dilemmas confronting disaster relief in Mainland China and put forward some corresponding countermeasures and suggestions, which could improve the future disaster relief system in Mainland China.