聚四氢呋喃生产应用及市场前景

聚四氢呋喃是一种性能优异的高分子材料,其生产技术比较复杂、工艺条件极为苛刻,下游产品主要是用于生产新型合成纤维氨纶.近年来,由于我国氨纶产业的高速发展,拉动了聚四氢呋喃的需求大幅增长.此外,在聚氨酯弹性体、酯醚共聚物等非纤领域中的应用尚处于起步阶段,发展潜力巨大.本文简要介绍聚四氢呋喃的合成工艺、生产现状、应用领域方面的一些情况,对聚四氢呋喃近期市场需求进行了分析,对国内相关的生产企业提出了发展建议,并指出国内若不能有效地开拓聚四氢呋喃的下游产品市场,今后几年供大于求的局面是不可避免的,竞争也将更加残酷,市场前景不容乐观.     

聚氨酯

生产聚氨酯模塑物的方法，聚氨酯泡沫材料的整体制备，一种用于尼龙膜复合的聚氨酯胶粘剂，用于人体腔道支架上的医用聚氯睹膜及其制备方法，结构阻燃型喷涂聚氯睹弹性体材料及施工方法，利用废旧聚氯睹(PU)鞋底生产的湿法聚氯睹(PU)树脂，利用废旧聚氯睹(PU)鞋底生产的干式二液型聚氯睹(PU)树脂。     

最新科技论文题录 有机化工

2,3,4,5-四氟苯甲酸的合成与应用 付春未来燃油催化剂的发展方向 生产符合环保法规的清洁燃料 潘元青等国内外建筑沥青生产技术的进展 刘东晖由氯乙酸副产盐酸精制高纯盐酸 杨会文等聚乙二醇二甲醚的合成及应用 朱新宝等环己酮下游产品的开发及应用 李俊辉聚四氢呋喃生产工艺评述 李正清等     

聚氨酯废旧料的回收利用

对聚氨酯材料特别是聚氨酯泡沫废料的回收再生方法及进展进行了评述。废旧聚氨 再生利用方法有：粘结制再生泡沫塑料,粉碎后热压成制品,粉碎成粉末作为生产泡沫塑料等的填料;通过醇解、胺解或水解工艺将泡沫分解再生多元醇,再用于泡沫塑料,等等。     

用１，４—丁二醇制四氮呋喃工艺研究

介绍１,４－丁二醇制剂四氢呋喃工艺改进情况,确定了较好的催化剂,最佳催化剂浓度,催化剂用量等条件,该实验采用氢氧化钠脱水,五氧化二磷化学脱水,精馏得四氢呋喃,ＴＨＦ收率优于国内国类工艺,产品质量达到日本产品指标。     

燃料电池质子交换膜用新型磺化聚芳醚酮的合成和性能表征

报道了一种新型磺化聚芳醚酮材料的合成方法，通过引人取代基对聚芳醚主链进行保护，用氯磺酸直接磺化方法在聚芳醚酮高分子侧基上引人磺酸功能基，实现了聚合物磺化结构的可控定位合成，得到了稳定性较好的磺化聚芳醚酮．通过核磁共振（NMR）、热重（TG）和凝胶渗透色谱（GPC）等分析方法对其结构及性能进行了表征．用溶液浇膜法制备了质子交换膜，考察了膜的各种性能，并与商用Nation膜进行了比较，其导电性、热稳定性和吸水性远优于Nation膜，抗氧化性、抗水解性和机械强度也达到了较高的指标．     

莱卡：时尚的纤维

2001年，“莱卡（Lycra）”入选美国服装设计师会评的“20世纪时装界最佳创意发明”，但它却不是服装。莱卡只是一根弹性纤维——一种学名叫氨纶的纤维。这种纤维只是服装的组成部分，只是一种隐身于幕后的典型B2B产品，然而当氨纶变身为“莱卡”，却被终端消费者熟知，甚至化身为时尚的代名词。     

中科院研发成功聚脂PTT单体技术

聚对苯二甲酸丙二醇酯是20世纪90年代中期开发出的新型聚酯材料，是生产聚酯纤维PTT、可生物降解的聚酯塑料、聚酯薄膜、聚氨酯的重要单体。其关键原料1，3-丙二醇(PDO)的合成技术成为目前世界各大跨国公司竞相开发的热点。     

环氧氯丙烷行业发展前景看好

环氧氯丙烷（ECH）别名表氯醇，是一种重要的有机化工原料和精细化工产品，主要用于生产环氧树脂、合成甘油、氯醇橡胶以及缩水甘油醚类等。     

灌木木质素成功生产聚氨酯泡沫

新西兰基因研究开发公司下属公司目前采用从灌木矮柳树种提取的木质素生产出聚氨酯泡沫材料。这项实验的成功显示了从灌木类植被中大量生产“绿色”塑料的可能性，从而有可能减少聚氨酯生产中所使用的石油化工原料。该公司目前正在扩大用木质素生产多种复合型塑料材料的实验研究。一家潜在客户对天然木质产品进行的导热性和密度测试已经取得满意结果，     

氨纶纤维的生产技术及发展趋势

本文概述了氨纶纤维的用途、生产方法和生产工艺，对氨纶纤维技术发展趋势、国内外氨纶纤维现况进行了分析，并着重对熔纺氨纶丝进行了介绍，对国内氨纶纤维的发展及外资企业抢滩中国氨纶市场的现象提出建议。     

城市地铁自助游市场需求分析——以南京为例

地铁自助游作为一种新兴的旅游细分市场正逐渐兴起。通过对南京自助游游客进行的问卷调查,分析地铁自助游市场的需求,结果显示:地铁自助游线路的开发拥有较好的市场前景和发展潜力;地铁站点与旅游景区之间的交通是否方便是决定地铁自助游能否成行的关键因素。     

协作多组多播认知无线网络的资源优化配置

考虑到无线电频谱资源日益紧缺,提出了一种基于组间组内协作传输的多播组新机制,涉及多个多播组并使用同一频谱资源以协作方式传输信息。基于认知无线网络中该机制,研究了系统的资源优化配置,理论分析得出了功率分配方案,进而讨论了系统加权总传输速率的优化,同时考虑了主用户和认知用户之间信号干扰及功率限制对传输速率的影响,最优化用户性能。仿真结果表明,优化方案下多播组传输速率随用户人数的增加而上升,达到最优化用户服务质量;当功率限制时,通过设置加权因子,能够保证主用户拥有良好的通信性能。     

A PROPERTY TAXATION MECHANISM WITH SELF‐ASSESSMENT

This paper analyzes a variant of the classic idea for property taxation based on owner's self‐assessment. To induce reporting of market values tax authorities announce to purchase some of the properties randomly at declared values under certain conditions. These conditions are based on properties of the distribution of declared values. It is proven that a unique Nash equilibrium of this taxation game among tax payers exists in which all of them report market values and tax authorities do not purchase any property.     

Some consequences of the early twentieth-century British divorce of ownership from control

Because ownership was already more divorced from control in the largest stock market of 1911 (London) than in the largest stock market of 1995 (New York), the consequences for the economy, for good or ill, could have been considerable. Using a large sample of quoted companies with capital of £1 million or more, this article shows that this separation did not generally operate against shareholders' interests, despite the very substantial potential for agency problems. More directors were apparently preferable to fewer over a considerable range, as far as their influence on company share price and return on equity was concerned: company directors were not simply ornamental. A greater number of shareholders was more in shareholders' interest than a smaller, despite the enhanced difficulties of coordinating shareholder ‘voice’. A larger share of votes controlled by the board combined with greater board share ownership was also on average consistent with a greater return on equity. Corporate governance thus appears to have been well adapted to the circumstances of the Edwardian company capital market. Hence the reduction in the cost of capital for such a large proportion of British business conferred a substantial advantage on the economy.     

基于零售物业竞争关系的商圈测定方法

零售物业的商圈测定一直是产业界和学术界关注的热点问题。现有的商圈理论尽管已经考虑到商圈重叠和多目的购物行为等因素的重要性,但尚未在各种商圈测定模型中对这些因素进行定量描述。分析传统的Huff概率模型存在的问题,并从反映零售物业竞争关系的角度对其进行改进,制定出更为符合实际情况的商圈测定方法。     

Welfare and market-access effects of piecemeal tariff reforms on environmentally preferable products

We examine how welfare and market access are affected by piecemeal tariff reforms on environmentally preferable products (EPP) in a small open economy. We define EPP as clean goods that, when consumed, have no impact on pollution. First, we show that a uniform reduction of all tariffs improves welfare if a country’s imports consist only of clean goods. If a clean good is a net substitute for all other goods in excess demand, then reducing the highest tariff on the clean good improves welfare. Second, we show that a proportional tariff reduction leading to a welfare improvement also increases the value of imports if all tariffs are set at the same ad valorem rates. If the clean good is a net substitute for all other goods in excess demand, then reducing the lowest tariff on the clean good increases the value of imports. Finally, we explore the link between the change in welfare and the change in the value of imports in response to the tariff reforms, and we show that unlike a proportional tariff reduction, a tariff reduction on the clean good does not necessarily lead to improvements in both welfare and market access.     

Multiple curve Lévy forward price model allowing for negative interest rates

In this paper, we develop a framework for discretely compounding interest rates that is based on the forward price process approach. This approach has a number of advantages, in particular in the current market environment. Compared to the classical as well as the Lévy Libor market model, it allows in a natural way for negative interest rates and has superb calibration properties even in the presence of extremely low rates. Moreover, the measure changes along the tenor structure are significantly simplified. These properties make it an excellent base for a postcrisis multiple curve setup. Two variants for multiple curve constructions based on the multiplicative spreads are discussed. Time‐inhomogeneous Lévy processes are used as driving processes. An explicit formula for the valuation of caps is derived using Fourier transform techniques. Relying on the valuation formula, we calibrate the two model variants to market data.     

标准市场机制效应与呈现特点研究

标准在中外贸易竞争中发挥着重要作用,根据标准的发布机构属性、区域和作用对象的不同,本文分析各种分类的标准共同组成一个开放、发展的庞大标准体系,研究了标准和标准体系对市场竞争、市场有序运行、国际贸易的促进作用,结合对标准固有属性的分析,认为实施标准的市场效用具有信息共享、促进创新、实现兼容、改进技术、建立消费信心、支撑国家法律、建立安全、环境规范等特点。     

Conditional market segmentation by neural networks: a Monte-Carlo study

An artificial neural network (ANN) algorithm is proposed that incorporates both market segmentation and discriminant (regression) analysis of the segments. The method simultaneously estimates the models relating consumer characteristics to market segments, i.e., subjects are assigned to (unique) segments so that subjects within a class show similar purchase behavior and share the same characteristics (psychographics/sociodemographics). Parameters of all models are estimated by the backpropagation algorithm. The performance of the ANN methodology is assessed in a Monte-Carlo study. In contrast to the usual stepwise approach adopted in segmentation studies, our study found that simultaneous segmentation and discrimination are preferable for finding an overall optimum in that this way clusters are formed not only to create homogeneous submarkets but also to show a good dicriminatory behavior.