国内外环氧乙烷生产发展概况

本文对国内外环氧乙烷生产技术现状、发展动向、以及市场供需状况作了概要叙述，并指出了提高我国环氧乙院国际市场竞争力的方法和措施。     

国内外环氧乙烷的生产及市场分析

本文综述了近年国内外环氧乙烷的生产状况并对市场前景进行了分析与预测,针对目前我国环氧乙烷的生产状况,提出了我国环氧乙烷的的生产和发展建议.     

Price versus quantity in a mixed duopoly with foreign penetration

We characterize the endogenous competition structure (in prices or quantities) in a differentiated duopoly between a public firm that maximizes domestic welfare and a private firm that can be owned by domestic or foreign investors. The market for which they compete can be domestic or integrated: in the first case Bertrand competition emerges endogenously and in the second case Cournot competition can emerge if the fraction of domestic consumers in the integrated market is low enough. We also determine the optimal degree of foreign penetration showing the optimality of a partial foreign ownership. Finally, we extend the model to increasing marginal cost confirming the robustness of the results.     

纳米VO2的制备及在智能控温包装材料中的应用

本文分别采用水热法和溶剂热法制备低维VO2（B）纳米材料,然后在N2（99．999％）氛围中将VO2（B）进行623K热处理,得到VO2（M）蓝黑色粉末。利用X-射线衍射（XRD）、X-射线光电子能谱（XPS）、红外光谱（FTIR）、透射电子显微镜（TEM）和高分辨力透射电子显微镜（HRTEM）等测试样品的成分及形貌特征。结果发现：水热法制得的VO2（B）经热处理后得到VO2（M）纳米带,该纳米带有数微米长,宽100～150nm,厚20～30nm,是典型的纳米带状结构;溶剂热法制得的VO2（B）经热处理后得到花瓣状纳米团簇的VO2（M）,该花瓣状团簇纳米材料由超薄薄片组装而成,长短不均,宽约数10nm。将VO2（M）纳米粉体、高分子分散剂和硅树脂混合制备得到智能控温包装材料（ICT—PM）;通过变温红外测试,发现以水热法和溶剂热法所制备的VO2（M）为基础的包装材料的相变温度为341K,这一结果为VO2（M）在智能控温包装中的应用奠定了基础。     

What prevents consumers that are aware of Airbnb from using the platform? A mixed methods approach

The hospitality sector is now characterised by the co-existence of traditional providers and sharing economy enterprises. It is important to better understand what prevents the use of peer-to-peer accommodation rentals in the tourism marketplace. Adopting a mixed-methods approach, this study first examines travellers’ Airbnb use constraints, and then profiles 252 Airbnb non-users based on their constraints and characteristics. The findings suggest that travellers do not use Airbnb because of distrust in the providers, in the platform and in other users, as well as perceived risk and unfamiliarity. Loss of service quality, lack of local experience, legal and regulatory issues, and disinterest also prevented consumers to book Airbnb accommodations. A cluster analysis divided non-users into three segments: Traditional travellers, Sharing economy misbelievers and Airbnb prospective users. Significant differences based on age confirmed that young travellers are more confident in using peer-to-peer accommodation platforms and more interested in the philosophy.     

Robust multivariate analysis for mixed-type data: Novel algorithm and its practical application in socio-economic research

We propose a novel method and algorithm for the analysis and clustering of mixed-type data using a hierarchical approach based on Forward Search. In our procedure, the identification of groups is based on the identification of similar trajectories and then linked to very intuitive two-dimensional maps. The proposed algorithm can use different measures for the calculation of distance in the case of mixed-type data, such as Gower’s metric and Related metric scaling. A key feature of our algorithm is its ability to discard redundant information from a given set of variables. The practical usefulness of the algorithm is illustrated through two applications of high relevance for empirical economic research. The first one focuses on comparing different indicators of environmental policy stringency in different countries. The second one applies our procedure to identify clusters of countries based on information regarding their institutional characteristics.     

Cluster Analysis for mixed data: An application to credit risk evaluation

Credit risk is one of the main risks faced by a bank to provide financial products and services to clients. To evaluate the financial performance of clients, several scoring methodologies have been proposed, which are based mostly on quantitative indicators. This paper highlights the relevance of both quantitative and qualitative features of applicants and proposes a new methodology based on mixed data clustering techniques. Indeed, cluster analysis may prove particularly useful in the estimation of credit risk. Traditionally, clustering concentrates only on quantitative or qualitative data at a time; however, since credit applicants are characterized by mixed personal features, a cluster analysis specific for mixed data can lead to discover particularly informative patterns, estimating the risk associated with credit granting.     

Corporate financial distress: The case of publicly listed firms in an emerging market economy

Occurrences of financial distress (FD) are not readily obvious yet can span several periods. This paper examines episodes of FD using industry‐relative (IR) firm‐/ accounting‐, market‐ and macro‐level information. Mixed logit regressions reveal that firm‐ and market‐based measures, as well as macro‐level variables explain the likelihood of FD in 263 publicly listed non‐banking firms in the Philippines during the period 1995 to 2018. Rates of identification of firms in financial distressed states of close to 69 percent are obtained at a cutoff probability of 0.30 in the model with time‐varying intercept and slope. This study shows the importance of recognizing heterogeneous firm behavior. The ability to more accurately predict the probability of FD and to determine the financial health of firms can help financial institutions in allocating funds and policy makers in predicting crises episodes.     

甘蔗渣灰中金属氧化物对灰熔融特性的影响

采用灰熔点测定、SEM-EDS分析、FTIR分析和XRD分析,研究甘蔗渣灰成分中不同氧化物CaO、MgO、Fe2 O3对甘蔗渣灰熔融特性的影响.结果表明:甘蔗渣灰中CaO和Fe2 O3的加入使甘蔗渣灰熔点降低,M gO的加入使甘蔗渣灰熔点小幅提升;CaO的加入形成了多种碳酸盐以晶体形式存在,碳酸盐之间形成低温共熔物,使灰熔点下降;MgO的加入虽然生成了多种碳酸盐相互之间会形成低温共熔现象,但由于部分MgO仍以简单的金属化合物的形式存在未参与反应,使得灰熔点有小幅提高;Fe2 O3的加入形成低温共熔物硅酸盐,但尖晶石的存在使灰熔点变化不明显.甘蔗渣灰熔点低的主要原因是新硅酸盐类和新碳酸盐类物质的生成,使其灰熔点提高可从硅酸盐类和碳酸盐类物质的减少或者高熔点物质生成量增加两个角度进行考虑.     

Virtual reality and mixed reality for second chance tourism

The deterioration of attractions, landmarks, artefacts and destinations is a critical issue facing tourism across the world. The closure of tourism sites and attractions is increasingly more common due to the difficulty and expense of managing preservation with onsite tourism engagement. However, the closure or destruction of tourism sites presents challenges for tourism development. The inability to foster meaningful visitor engagement at sites has implications for the local communities. This paper aims to explore the efficacy of creating tourism experiences in destinations and sites that have succumbed to over-tourism, resultant deterioration and even, destruction. To achieve this objective, the paper introduces the concept of second chance tourism and the role of innovative preservation methods such as virtual and mixed reality. Based on the proposed framework, the collation of data will provide indications on site preservation and impact mitigation via a second chance to reduce pressure on inherently fragile destinations.