基于人体膳食均衡视角下的我国果蔬消费趋势预测与结构优化

水果和蔬菜是为人体提供矿物质、维生素、膳食纤维等营养元素的重要农产品,我国居民饮食中普遍存在着能量相对过剩、果蔬摄入量不足的问题。以人体膳食均衡为研究视角,研究我国果蔬消费趋势和结构优化问题,结果表明：按照当前的消费趋势发展,我国居民营养摄入不足与过剩同在的问题依然无法得到解决;我国政府在制定水果和蔬菜战略布局的决策中,应综合考虑人体的膳食营养均衡和未来市场营养需求,以实现我国果蔬产业布局优化;消费者在进行水果和蔬菜消费购买行为时,应在营养膳食均衡的基础上进行合理消费。     

结构优化对我国农产品出口竞争力的影响

应用产业组织理论,揭示结构优化对农产品国际竞争力的作用机理。以RCA衡量农产品出口竞争力并建立多元回归模型,在有效分离工资、土地灌溉面积和汇率等因素后,实证研究发现技术结构对农产品出口竞争力有显著正向影响。当前经济背景下,提升农产品出口竞争力的政策思路,需从传统的要素禀赋优势转移到结构优化的轨道上来。优化农产品出口结构,政府需加大对高附加值农产品在生产、流通、出口等环节的支持力度,营造寡占的农产品市场结构,鼓励和扶持创意农业的发展。     

基于灰色系统的小型精密机床热误差模型

为减少热误差对数控机床加工精度的影响,文章利用灰色系统研究热误差建模。初步分析机床热源后,应用灰 色关联度分析结合模糊分类方法优化得到13组关键温度测点,结合小型精密五轴机床处于实际加工状态时的实验数 据,应用GM(I,N)灰色结构进行建模。将实际数据与拟合数据进行对比分析,结果表明此灰色系统模型具有计算方法 成熟、鲁棒性强的特点,适用于机床热误差研究。     

模具钢干铣削试验及参数优化研究

为了对铣削力做进一步的研究,以及预测铣削参数的改变对铣削力变化的影响,文章建立了铣削力预测模型,引 入了PSO优化算法。试验采用正交设计方法,干式铣削SKD61模具钢;KISTLER测力仪测量铣削力;HRsoft_DW数采软 件采集试验数据,并对数据进行极差分析。研究结果表明每齿进给量是铣削参数中影响铣削力最为主要的因素。研究 验证了PSO算法对铣削参数优化问题具有有效性。     

新制度经济学视阈中的当代中国意识形态建构

整体上看,中国的意识形态为改革演进起到了新制度经济学所说的良好的社会动员、社会整合和激励作用,确保了改革的成功。但主流意识形态在理论和现实的挑战与冲突中趋于弱化,也是不争的事实。建构当代中国的意识形态,要以马克思主义为指导,牢牢把握先进文化的前进方向;应把个人精神生活、一般思想理论与国家意识形态适当分离,在个人观念的竞争中实现接合;应提炼现实、接轨世界、转型话语,以社会公正与和谐为中心进行价值重组,积极创新与发展马克思主义,赢得接合中的主导权;应继续保证政治统治的"绩效合法性"。     

大学生认知方式与德育方法的优化

认知方式划分为场依存和场独立两种类型,大学生认知方式与德育方法实施产生的效果有相关性。笔者认为应构建"以人为本"的德育方法论体系,根据大学生不同的认知方式采取分类指导原则,实施相应的有针对性和实效性的德育方法。     

Does the β-measure make empirical sense? A vignette experiment on humans’ judgment of social dominance

Dominance hierarchies play an important role in governing the social interactions of humans and other species of social animals. In a social group, dominance relations can be inferred from the directed network of matchups between actors. Methodologists have proposed different ways to measure social dominance in directed networks. One such measure, the “β-measure” (van den Brink and Gilles, 2000), emphasizes the quality of defeated opponents in a way that an actor is seen as being more dominant when s/he defeats opponents who are more rarely defeated. While insightful in theory, the validity of the measure in people’s perception remains questionable, considering the cognitive complexity imposed by this measure, compared to a simpler measure that merely counts the number of defeated opponents. We conducted a vignette experiment with human subjects (professional athletes) to test their judgments of the dominance relation in a hypothetical tournament. Fitting our parametric model to peoples’ evaluations in the experiment, we found strong evidence in support of the β-measure: Although, in general, contestants who win more in the tournament are regarded as being more dominant, the contents of the winning records matter, such that those who beat more victorious opponents are further regarded as more dominant than those who defeat less victorious opponents. We also found a gender difference, in that men have a stronger propensity than women to adopt the β-measure when judging social dominance.     

数字化发展、制度环境与政府舆情治理质量

基于2016—2020年我国31个省级行政区的面板数据,考察数字化发展、制度环境与政府舆情治理质量之间的关系。研究发现,数字化发展对政府舆情治理质量具有改善效应;相比制度环境较差的省份,数字化发展对舆情治理质量的改善效应在制度环境较好的省份更为显著。异质性检验表明,数字化发展对政府舆情治理质量的改善效应在数字化水平高的省份、制度环境较好但数字化水平低的省份显著,在制度环境较好的省份、制度环境较差的东部省份显著。研究结论为借助数字化发展改善政府舆情治理质量提供了理论依据。     

Parametrizing the Kepler exoplanet period-radius distribution with the bivariate normal inverse Gaussian distribution

This paper presents a simple and robust method for obtaining a comprehensive understanding of the joint period and radius distribution in Kepler exoplanets. The proposed method is based on particle swarm optimization and bivariate Normal Inverse Gaussian distribution. Furthermore, in the construction of the probability density function, this study selects planet-host stars with the GK-type. The injecting approach is also employed to solve the survey completeness of sample. The resulting occurrence rate of Earth analogs is 0.025 with a 95% bootstrap confidence interval between 0.023 and 0.032.