我国丘陵山区农机化水平影响因素及区划研究*——基于全国丘陵山区238个县（市）的调研数据

[目的]通过对全国丘陵山区县(市)与农机化有关的社会、经济和自然条件等因素进行调研所获取的238个有效样本进行分析,研究影响我国丘陵山区农机化水平的因素及其贡献,进而对我国丘陵山区进行区域划分。[方法]运用线性回归法对影响丘陵山区农机化水平的影响因素进行分析,进而对农机化水平产生显著影响的因素进行聚类分析。[结果]国内生产总值、农业劳动力数量对农机化水平产生极显著影响,耕地禀赋条件、务工工资、耕地规模、农机合作社数量和农机推广人员数量对农机化水平产生显著影响。对我国丘陵山区农机化水平呈正相关关系的因素有国内生产总值、务工工资、耕地规模、农机合作社数量,呈负相关的因素有耕地禀赋条件、农业劳动力数量、农机推广人员数量和农机化水平。[结论]我国可丘陵山区划分为中西、东南部地区,北部地区和东部沿海地区3大类地区。     

Are they telling the truth? Revealing hidden traits of satisfaction with a public bike-sharing service

Public bike-sharing systems (BSSs) are an emerging mode of transportation introduced by municipalities to solve congestion problems in metropolitan areas, especially when integrated with other types of transportation. In the last years, the number of public bike-sharing services has been constantly on the rise all over the world, and generally the overall satisfaction with them is high. However, satisfaction with public services is driven by mechanisms that can differ from those in the private sector. It is important to establish to what extent a high satisfaction is genuine or simply ephemeral. Even “old” public services (like public transportation) become “gold” when accompanied by the introduction of new technologies. In this paper we analyze this phenomenon using data from a satisfaction web-survey conducted among customers of the public BSS “BikeMi” in Milan, Italy, in a period when mobile technologies have been introduced to speed up the service. On analyzing the responses to satisfaction questions using simple summary statistics, the level of satisfaction resulted very high. However, our aim was to look for potential “darker” sides of the service by detecting possible hidden satisfaction components. For this purpose, we used the Nonlinear Principal Components Analysis, which is particularly powerful in this context. A simple textual analysis was also performed as a validating test. Results from our analysis indicated that satisfaction is flawed by a set of factors like the mechanics of the bikes, the picking and dropping system, and the apps used to organize the service. Less concern was detected for more general aspects of the service.     

Spatial movement patterns among intra-destinations using social network analysis

To explore popularly visited tourist locations, travel movement patterns, and movement points, this study collected samples of 321 Chinese tourists and 337 Japanese tourists who were visiting major tourist destinations in Seoul and its vicinity in South Korea. Results of analyzing movement patterns showed that Japanese tourists tend to be clustered around popular attractions, whereas Chinese tourists tend to spread over a larger area of attractions. Some specific shopping and amusement attractions were the locations most popularly visited by both groups. The start points and end points in the two groups’ itineraries were dissimilar overall, even though their patterns were similar in regard to major preferred tourist attractions. Thus, the findings of this study have the potential to contribute to understanding spatial mobility in a tourism destination through tracking tourists’ movement patterns.     

宫腔积脓1例临床分析

目的探讨绝经妇女宫腔积脓的原因、诊断及治疗方法。方法对牡丹江医学院红旗医院收治的1例绝经妇女宫腔积脓的临床表现及辅助检查进行回顾性分析。结果引起绝经妇女宫腔积脓的原因与老年性阴道炎和子宫内膜炎、绝经后不及时取出节育器及合并子宫内膜癌有关。临床表现为腹痛、发热、阴道排液(阴道出血),经过详细的询问病史、妇科检查、适当的实验室检查可明确诊断。结论绝经妇女宫腔积脓病程进展缓慢,临床表现不典型,易误诊,有时可引起严重的并发症,应针对原因进行预防,早期诊断,及时治疗。     

Organizational learning in exporting: A bibliometric analysis and critical review of the empirical research

In the latest decades, empirical research on organizational learning in the export context has recorded an increasing trend. On the other hand, in spite of the wealth of research on the subject, no effort has yet been made to offer an integrative review to investigate the improvement of this body of knowledge. To fill this gap, this study endeavors to synthesize the stream of empirical research on organizational learning in the field of exporting published between 1997 and 2017. Initially, the relevant studies were bibliometrically analyzed on the basis of the data gathered from the Web of Science database. The bibliometric data analysis indicates the most influential publication outlets, most influential institutions, most influential scholars, and most influential articles in relation to organizational learning in the export literature. Additionally, each article was content-analyzed in terms of scope of research, research methodology, and empirical issues. The content analysis reveals that albeit significant progress, organizational learning research within the context of exporting is still at the introduction stage and certain weaknesses in scope, research designs, and conceptual understanding attract criticism.     

Defining Ownership: An empirical assessment of the ownership measures

Ownership is considered to be one of the crucial governance mechanisms; however, there have been no systematic attempts at validating the construct and measures used to operationalize ownership. We review the current understanding of ownership and the measures used by each perspective, namely blockholder/dispersed shareholder perspective, owner identity perspective, and aggregated ownership perspective. We thereafter critique each of these perspectives, offer hypotheses regarding their validity, and empirically assess each ownership measure vis‐à‐vis firm performance outcomes. We utilize a sample of 3,990 US firms to test our hypotheses and find no consistent results for the blockholder measure, or for the owner identity measure. However, the aggregated ownership measure consistently accounts for significant increases in explanation of variance in firm performance. Copyright © 2018 ASAC. Published by John Wiley & Sons, Ltd.     

COMPARING PPP WITH TRADITIONAL PROCUREMENT: THE CASE OF SCHOOLS PROCUREMENT IN IRELAND

Advocates of public‐private partnerships (PPPs) argue that they can deliver public infrastructure more efficiently than traditional procurement through timelier completion and superior value for money. Despite these claims comparative analysis of the performance of both procurement methods has received scant attention in the PPP literature to date. This paper addresses this issue by providing an in‐depth, case‐based comparison of PPP versus traditional procurement in the schools sector in Ireland. Through detailed semi‐structured interviews with key stakeholders and an examination of the available documentation, we assess whether the key objectives of using PPP have been achieved. Overall, we find no evidence that PPP leads to faster delivery of infrastructure when the overall procurement process from contract notice to delivery is accounted for. In addition, we find only limited evidence to suggest that PPP results in better value for money.     

自动涂胶系统胶枪的热分析

为研究自动涂胶系统的胶枪最优材质、最佳热源位置和最佳测温位置,利用ANSYS Workbench软件对自粘胶胶枪进行数值模拟.通过分析不同材质胶枪的温度场分布情况,结合经济性和加热性能,选定最优胶枪基材.同时分析得出加热自粘胶至工作温度的时间和保持工作温度的加热功率,确定了热源和测温点位置,拟定了升温策略.进行自粘胶胶枪加热试验,验证了仿真分析结果的准确性.     

Economic Impacts of the Possible China–US Trade War

This article uses a multi-country global general equilibrium (GE) model to numerically simulate the effects of possible China–US trade wars. We introduce an endogenous trade imbalance structure with trade cost into the model which helps to explore both tariff and non-tariff trade war effects. Our simulation results show that China will be significantly hurt by the China–US trade war, but negative impacts are affordable. The US can gain under unilateral sanction measures to China, but will lose if China takes retaliation measures. Comparing the effects under mutual trade war, China will lose more than the US. Introducing non-tariff barrier trade wars will intensify the negative effects, and comparatively negative effects to China are larger than to the US. Mexico’s involvement in trade war with the US will strengthen the negative effects and comparatively hurt the US more. Under non-cooperative and cooperative Nash bargaining equilibrium, the US can gain more than China in trade war negotiation, which means the US has stronger bargaining power than China. Additionally, trade wars between China and the US will hurt most countries and the world especially in GDP and manufacturing employment, but benefit their welfare and trade.     

粮食安全与农业结构调整水平的协整分析*——以广东省为例

[目的]实现我国粮食安全与农业结构调整之间(即粮食增产和农民增收)关系的协调,较长时间以来是学界、政界关注的重要议题,但定量分析两者之间内在依存关系的研究一直欠缺。[方法]文章采用协整分析及Granger因果关系检验方法,以广东为例,对我国粮食安全(用粮食总产量来衡量)与农业结构调整水平之间的协整性及因果关系进行了研究。[结果]广东粮食总产量与反映农业结构调整水平的3个指标之间均存在长期均衡关系,且农作物播种面积中粮食作物面积对广东粮食总产量影响最大,每下降1%,粮食总产量下降0. 659 548%。短期内,反映农业结构调整水平的3个指标对广东粮食总产量的影响均存在波动,但由短期偏离拉向长期均衡的牵动作用均较弱。Granger因果关系检验表明农业在国民经济中的比重、农作物播种面积中粮食作物面积早期对广东粮食总产量产生单向影响,但影响程度相对较弱。[结论]提出应从农业结构调整以外的因素着手提高我国粮食安全水平,并通过调整农业区域结构去缓解我国粮食供求市场的结构性矛盾。