手性液相色谱在活性药物分离中的应用

具有手性中心的药物,其两种对映异构体通常在体内表现出不同的药理活性和药代动力学性质,为了对单一对映异构体的药理行为和代谢途经进行研究,必须发展手性药物的分离分析方法。为此,本文就基于手性固定相的手性液相色谱研究进展做一综述。     

酶催化拆分外消旋药物的研究进展

外消旋药物中通常存在不同的对映异构体,但在药物中往往只有一种对映体才具有实际的疗效,这不仅可以排除由于无效(不良)对映体所引起的毒副作用,还能减少药物剂量和人体对无效对映体的代谢负担,对药物动力学及剂量有更好的控制,提高药物的专一性。脂肪酶作为一种特殊有效的生物酶催化剂,利用其高度立体选择性将外消旋体拆分成单一光学异构体,底物转化率和对映体选择性较高,反应条件温和且副反应较少。文章对酶催化拆分外消旋化合物的现状和影响因素进行了综述。     

手性化合物拆分方法之研究

文章针对手性化合物拆分,首先分析手性化合物,了解基本概念,其次阐述手性化合物的三个来源渠道,最后从结晶法、化学拆分法、酶法拆分法三个方面论述手性化合物比较常用的拆分方法,提高拆分效果的同时,明确手性化合物分离重要作用。     

原子层沉积对膜材料改性的研究进展

随着膜分离技术在各领域中的应用和推广,也涌现了诸多膜表面改性技术。在诸多表面改性方法中,原子层沉积由于其共形和三维可控的优点而逐渐受到关注。文章将从发展历程、沉积原理和改性方向对原子层沉积技术进行分析,对改性技术的研究和发展提供参考。     

不对称合成正在走进活性药物成分规模化生产

1不对称合成是一个充满机遇与挑战的开发领域 1．1单一对映体药物的需求推动着手性技术的发展 大自然有一种通晓如何造物的方法。许多反应往往是以某种催化模式进行的，使原料与能量消耗和废物产生都降到最低。许多分子是手性的，它们独特的左手或右手结构，对于它们如何与生物系统相互作用，具有既复杂又戏剧性的影响。在药物中立体选择性相互作用是极为重要的，     

高分子渗透汽化膜分离技术的应用

高分子渗透汽化膜分离技术能够有效地解决水资源短缺和水污染等问题,具有广阔的应用前景。但随着高分子渗透汽化膜分离技术在水处理中的应用不断扩展和深化,未来也将有更多的问题需要进一步探索和解决,例如如何提高膜的分离性能和降低成本等。相信通过进一步研究,该技术在水处理领域的应用前景将更加广阔。     

膜处理技术在高盐废水零排放上的应用及展望

膜分离及膜浓缩工艺主要有微滤、超滤、纳滤、反渗透、高压反渗透、正渗透、电渗析ED、膜蒸馏等。文章通过对各种膜处理工艺的介绍,探讨膜处理工艺在高盐废水零排放的应用,寻找最经济环保的零排放膜工艺组合。     

疏水性L-酒石酸正戊酯的合成

疏水性L-酒石酸正戊酯是一种拆分对映体的重要手性试剂，在手性选择体、对映体的萃取，立体选择性萃取，手性助剂不对称合成及高效液相色谱流动相添加剂等方面中的应用研究日益增多。     

膜生物反应器处理废水的研究及应用

膜生物反应器将生物处理与膜分离技术相结合,是一种高效的废水处理新技术。在城市污水处理、中水回用、工业废水处理等方面的研究及应用实践表明,膜生物反应器具有常规废水处理工艺无法比拟的优势。根据国内外的研究及应用现状介绍了膜生物反应器的类型、特点及在废水处理中的应用,并对其在废水处理与回用中的应用前景进行了展望。     

无机陶瓷膜应用技术

简单介绍无机陶瓷膜分离技术的进展;评述无机陶瓷膜分离技术在生物发酵液分离浓缩领域应用的进展情况。当前无机膜分离浓缩技术应用广泛,因其耐高温、耐高压、耐化学腐蚀、可再生清洗,分离精度高、使用寿命长等优点多应用到发酵液分离、浓缩以及精制领域,对此做了论述。     

气体膜分离在环境保护中的应用

气体膜分离作为新兴的分离技术,已广泛应用于石油化工、能源、电子、医药、食品等领域。着重介绍了气体膜分离技术在环境保护领域的应用研究,包括有机蒸气(VOCs)的分离及酸性气体的分离,同时展望了该技术的发展趋势。     

膜分离技术及其在废水处理中的应用

基于膜分离技术是一种新型高效的分离技术,且其过程无相变、能耗低、适应范围广,愈来愈为人们所重视,并在多个领域发挥着巨大的效能。介绍了膜分离技术的发展过程与现状,着重综述了近年来膜分离技术在废水处理中的应用,分析了存在的一些问题并对其发展趋势作了展望。     

The momentum for network separation: A guide for regulators

Next Generation Access Networks (NGAs) are a challenge to regulators and operators insofar as they require large investments, there is a significant uncertainty about the ability to recover costs, and the choice of the appropriate regulatory regime is far from consensual. Regulatory authorities might want to seize the moment and reconsider mandatory vertical separation of telecommunication firms, without jeopardizing incentives to innovation and investment. This paper discusses the main elements of a possible test for the adequacy of network separation as a regulatory remedy. A sequential decision tree procedure with three questions is proposed: (1) “Is there significant market power in the provision of access under NGAs?”; (2) “Are there little vertical complementarities between services along the supply chain?”; and (3) “Is network separation a better regulatory tool than any other alternative?”. A positive answer to all the questions implies that the regulator should consider network separation as a regulatory remedy.     

Means not ends: Deterring discrimination through equivalence and functional separation

It is sometimes forgotten that the much debated remedy of functional separation is simply a means to an end. That end is to reduce the incentives for discrimination by the integrated firm, which damages its downstream rivals and ultimately harms competition and the interests of consumers. Functional separation, though now considered to be at the centre of the Undertakings was in fact not mentioned by name in them. This article examines the background to the Undertakings and why non-discrimination and accounting separation remedies were inadequate to deter sabotage behaviour. It draws on interviews with UK industry participants to consider whether equivalence and functional separation are “fit for purpose”. Although not perfectly implemented, the remedies have reduced discrimination and have helped to create the right conditions for dynamic efficiency gains in access and downstream broadband markets. However, there has been little or no “spillover” benefits into product markets not covered by the Undertakings.     

走进中美广电传媒,看“制播分离”如何当家

制播分离是广播电视体制机制改革与创新的主要内容之一。美国是最典型的"制播分离"的国家,早已形成了完整的节目投资、生产机制、节目营销机制以及节目质量反馈机制。网台分离、制播分离是美国三大电视网的基本运作制度。本文通过对美国"制播分离"运作机制的深入剖析,引出其先进的广电传媒运行机制对我国广电媒体的启示。     

The Italian way to functional separation: An assessment of background and criticalities

The paper describes the approach to functional separation followed in Italy. The analysis places the notion of functional separation in the context of the reform of the European Regulatory Framework in particular the Access Directive of the European Commission. It concentrates on the two main aspects of functional separation in the Italian telecommunications market: (i) the creation of an Open Access unit and (ii) the undertakings suggested by Telecom Italia and approved by AGCOM with the Decision 718/08/CONS. The paper shows that even if these measures are primarily aimed at fostering transparency, promoting equal access and non-discrimination practices, some doubts remain with respect to the impact of functional separation on incumbency of Telecom Italia. It proposes that the outcome of functional separation will have to be determined by joint efforts of regulation by AGCOM and changes in the strategy of Telecom Italia.     

Functional separation in Swedish broadband market: Next step of improving competition

Technological development together with liberalization policy has led to competition in the telecommunications market. Broadband has been recognized as a driving force in the social and economic development of nations, and many countries have introduced policies and/or regulatory frameworks to improve competition in broadband markets. An evolution can be seen from the 1980s until the present day through open access to local loop unbundling to several degrees of separation including functional separation. There are several countries implementing functional separation such as the UK, Italy, Sweden and, recently the EU. It has been suggested that functional separation can be an effective policy for increasing competition in broadband markets under certain circumstances. Sweden has implemented functional separation by amending the Swedish Telecommunications Act in 2008 to include mandatory functional separation as one of the powers of the PTS, the Swedish telecommunications regulator. Although TeliaSonera, the incumbent fixed line operator decided to voluntarily separate part of their business, the amendments to the law were debated with arguments similar to the debates in the EU following the new regulatory framework implemented in 2009. Against this background, this paper provides an overview of the development of functional separation in the EU and European countries such as Sweden and the UK. The paper also provides a theoretical and empirical analysis of the implementation of functional separation. The evolution of functional separation in Sweden is explained and ends with a discussion of the implementation of functional separation in the Swedish broadband market.     

输配电网分离的定量研究

在输配分离改革讨论中,一个非常重要的考虑是纵向经济损失问题。本文通过建立输配电二次成本函数,对输配分离改革产生的对称性和非对称纵向经济损失进行了实证研究。研究结果显示输配分离改革会带来巨大的改革成本,因此输配分离改革暂时不宜推行,除非预期改革收益远大于这些成本。     

前脱丙烷前加氢流程技术经济分析

介绍了茂名乙烯装置的分离流程，从技术经济的角度分析和研究了前脱丙烷前加氢技术，并与顺序分离流程进行了对比。