强弱电干扰与电网接地方式

伴随着世界科技的飞速发展,遍布世界各地的有线通讯和无线通讯技术,已经构成了一个密集的网络系统。同时,为了与国民经济的发展相协调,电力网进行了扩建,建设了很多变电站,无论是在地下还是地上,都构成了一个复杂的电网系统。强电和弱电这两大网络与国民的生活紧密相连。这势必将导致电网和道路之间的干扰,本文就此干扰的矛盾进行了相关的分析,以期为解决它们之间的问题提供帮助。     

中国小麦生产的时空演变特征及其影响因素分析

［目的］分析小麦生产的时空演变特征及成因,可以掌握小麦生产的时空分布规律,从而更加合理地配置农业资源,优化农业生产的空间布局,推动农业供给侧结构性改革,保障小麦产业的稳定发展。［方法］首先利用基尼系数、产业集中度指数等指标对1978—2016年我国小麦生产的时空演变特征进行分析,然后建立空间面板杜宾模型定量研究我国小麦生产布局变化的驱动因素。［结果］］改革开放以来,我国小麦生产逐渐向优势区域集中,集中程度不断提高,呈现出由东向西、由南向北的空间移动趋势,并且小麦生产表现出较强的空间依赖性。实证研究结果表明,农村劳动力的非农就业机会对小麦生产规模具有显著的负向影响,小麦生产的比较效益、农业机械化发展水平和小麦的平均产量对小麦生产规模具有显著的正向影响,此外小麦生产的比较效益和农业机械化发展水平还对邻近地区的小麦生产规模具有正向溢出效应。［结论］为保证我国小麦供给的安全,应进一步提高小麦的单产水平,大力提升小麦耕、种、收等环节的机械化水平,并不断提高小麦种植的比较效益。     

Financialization and commodity prices – an empirical analysis for coffee,cotton, wheat and oil

Commodity prices have crucial implications for developing countries. The question whether the financialization of commodity derivative markets has contributed to high and volatile commodity prices has been controversially debated. Building on limitations in the empirical literature, we estimate a multivariate Vector Autoregressive (VAR) model to assess the effect of different groups of financial investors (index investors and money managers) as well as fundamental and macroeconomic variables on the prices of coffee, cotton, wheat and oil. We find that, in contrast to index investors, money managers’ net long positions have a large statistically significant effect on commodity prices. This calls for policy interventions as commodity derivative markets may cease to perform their fundamental developmental roles.     

基于战略网络视角的企业关系资源

通过企业的战略网络视角分析在经济全球化背景下企业的战略选择,企业如何认识自己所需要的战略资源,从而获得竞争优势。在企业的战略网络视角下,企业的经营不再单纯考虑自身的利益而且还要考虑企业的战略联盟的利益,企业将以基于企业间关系的合作战略作出战略抉择。企业的价值将依据网络和竞争情况的演化而变化。     

潢川贡面制作工艺研究

潢川贡面为河南地方性特色贡面,营养价值高、口感独特.本研究以高筋面粉为原材料,探讨潢川贡面的最佳制作工艺条件,采用单因素试验和正交试验探讨食盐添加量、醒发时间、碱添加量和食用油添加量对潢川贡面感官评分的影响.结果表明,100 g面粉中,食盐添加量1.5 g、碱添加量1.2 g、食用油添加量4 g及醒发时间40 min,...     

Are multiple labels on food products beneficial or simply ignored?

This study examines consumer preferences and willingness to pay (WTP) for organic wheat products exhibiting single labels, as well as multiple labels, including organic. The additional labels considered are related to the organic label (non-genetically modified organism [non-GMO]) or perceived as health-promoting (gluten-free, low-carb, sugar-free). Study data were collected using a consumer survey conducted online in 2017 across 16 U.S. western states and analyzed using random parameter logit models. Findings show that organic-labeled wheat products with additional claims were valued equally or less than the organic only version. Overall, consumer higher objective and subjective knowledge of organic standards, as well as preferences for gluten-free products, increased their WTP for organic wheat products. Consumers unfamiliar with organic standards valued the non-GMO label over the organic label. Additionally, consumer WTP for health-related claims on hedonistic products was low or even negative. Hence, multiple labels on organic products generally provide no additional consumer benefit and are likely ignored. Study findings suggest that using the claim that most distinguishes the product, or is most salient, may improve product pricing. Also, non-GMO certification rather than organic certification should be considered for some markets. Finally, consumers with preferences for gluten-free products represent a potential market for organic wheat products.     

Epistemic equivalence of extended belief hierarchies

In this paper, we introduce a notion of epistemic equivalence between hierarchies of conditional beliefs and hierarchies of lexicographic beliefs, thus extending the standard equivalence results of Halpern (2010) and Brandenburger et al. (2007) to an interactive setting, and we show that there is a Borel surjective function, mapping each conditional belief hierarchy to its epistemically equivalent lexicographic belief hierarchy. Then, using our equivalence result we construct a terminal type space model for lexicographic belief hierarchies. Finally, we show that whenever we restrict attention to full-support beliefs, epistemic equivalence between a lexicographic belief hierarchy and a conditional belief hierarchy implies that an arbitrary Borel event is commonly assumed under the lexicographic belief hierarchy if and only if it is commonly strongly believed under the conditional belief hierarchy. This is the first result in the literature directly linking common assumption in rationality (Brandenburger et al., 2008) with common strong belief in rationality (Battigalli and Siniscalchi, 2002).     

On the standarized empirical process

In this note a new proof of a theorem of CSAKI (1975, 1982) concerning the almost sure behaviour of the standardized empirical process is established.     

Continuous representations of interval orders based on induced preorders

Conditions are given for the existence of a pair of continuous real valued functions (u, v) representing an interval order on a topological space (X, ), in the sense that [xy if and only ifu(x)].I am deeply indepted to Professor Alain Chateauneuf for many valuable suggestions.