4，4’-二氟二苯甲酮需求快速增长

4，4’-二氟二苯甲酮又称4，4’-二氟苯酰苯，是1种重要医药化工中间体，主要用于合成新型强效脑血管扩张药物氟苯桂嗪及治疗老年神经性痴呆症药物“都可喜”等。     

4，4＇-二环己基甲烷二氨基甲酸甲酯的制备及结构表征

以4,4＇-二环己基甲烷二异氰酸酯（H12MDI）和甲醇为原料,以二月桂酸二丁基锡（DBTDL）为催化剂制备了4,4’-二环己基甲烷二氨基甲酸甲酯（HMDC）。利用熔点测定、红外光谱、元素分析、核磁分析和质谱等手段对得到的两种固体产物A和B进行了表征。结果表明物质A为反-反结构的HMDC;物质B为一混合物,其中不仅含有反-反结构的HMDC,也含有顺-反结构和顺-顺结构HMDC中的至少一种。     

N-甲基-邻苯二甲酰亚胺的合成

N-甲基-邻苯二甲酰亚胺(NMP)合成方法主要有2种：一种是用邻苯二甲酰亚胺钾盐和碘甲烷的烷基化反应制备(收率为77％)，或用邻苯二甲酰亚胺的钾盐二酰亚胺和对甲苯磺酸甲酯发生烷基化反应；另一种方法是基于苯酐和气体或液体甲胺反应，本方法包括2步反应，苯酐和甲胺     

4-硝基-N-甲基-邻苯二甲酰亚胺的合成

N-甲基-邻苯二甲酰亚胺(NMP)主要用于合成4-氨基-NMP，4-氨基-NMP及其衍生物可用于荧光和其它标记研究。它是合成异鲁米诺及其衍生物的重要中间体。     

新型除草剂硝磺草酮的绿色合成探析

文章探讨了新型除草剂硝磺草酮绿色合成方法。原料选用2-硝基-4-甲砜基苯甲酸,通过氯化、缩合、重排反应完成硝磺草酮的制备。最终合成的产物达到了95.0%的衬度、87.0%的总收率。该合成方法可将硝磺草酮合成过程中使环境受到的损害大幅度减少,安全系数更高,在工业化生产中十分适用。     

二硝:洗牌悄然到来

<正>2,4-二硝基氯化苯(俗称二硝),是重要的精细化工中间体,被广泛应用于医药、农药、染料、民爆、化学助剂等领域,以前主要用于合成硫化染料硫化黑、染料中间体和农药等。这些产品多属传统产品,近几年市场需求渐少,因而导致二硝市场相对疲软,发展瓶颈始终无法突破。笔者最近在调研时发现,当前随着国家对技术创新、绿色环保、结构调整等方面的要求提高,二硝企业的洗牌与蜕变正悄然到来。国内需求仅为产能一半左右     

亚氨基二乙腈的生产现状与市场前景

亚氨基二乙腈是一种重要的有机精细化工中间体,主要用于合成除草剂草甘膦,与草甘膦的生产、发展有着密切的关系,在染料、橡胶、化肥、电镀、医药、建材、水处理、食品加工、合成树脂、电子电器等领域也有广泛的用途。工业化生产亚氨基二乙腈主要有天然气路径和石油路径两种,天然气路径在国内的研究开发已取得突破性进展,建成了工业化生产装置,为草甘膦的生产提供了优质价廉的原料,并使草甘膦生产工艺发生了根本性的变革。文章还介绍了亚氨基二乙腈的生产技术、国内现状、应用领域及市场前景,并对国内亚氨基二乙腈产业的发展提出了一些建议。     

二苯氯甲烷的合成新工艺

二苯氯甲烷是一种重要的医药中间体，可制备众多的各类药物，因而二苯氯甲烷的合成具有重要的意义。     

偶氮苯的合成与研究进展

偶氮苯-一种光响应因子和有机染料,越来越受到人们的广泛关注,越来越受到世界各国的重视。随着时代的发展,偶氮苯的研究不断深入,合成方法不断改进。文章总结归纳了偶氮苯类化合物的主要性质,重点介绍了常用的、应用比较广泛的有机合成方法。探讨了偶氮苯类化合物未来应用前景,希望为广大偶氮苯类化合物合成研究提供一定参考价值。     

三甘醇双[3-（3’，5’-二叔丁基-4’-羟基苯基）丙酸]酯的合成

酚类抗氧剂是所有抗氧剂中不污染、不变色性最好的一类，具有很好的抗氧化能力，大量用于塑料、合成纤维、橡胶、燃料、润滑油和食品等领域，尤其是受阻酚抗氧剂倍受重视。受阻酚类抗氧剂近30年来的开发研究非常活跃，作为主抗氧剂已在高分子领域得到广泛的应用。三甘醇双[3-(3’，5’-二叔丁基-4’-羟基苯基)丙酸]酯与同类酚类抗氧剂结构类似，具有优良的性能，如不着色、无毒、热稳定性好、与树脂的相容性好等，可用于制备苯乙烯聚合物、聚氯乙烯、聚氨酯、聚缩醛、聚酰胺、羧基化丁基橡胶及丁苯乳胶等聚合物。现介绍以3-(3’，5’-二叔丁基-4’-羟基苯基)丙酸甲酯(简称3，5-甲酯)和三甘醇为原料，有机锡为催化剂，甲苯为溶剂，合成了三甘醇双[3-(3’，5’-二叔丁基-4’-羟基苯基)丙酸]酯。     

增强Linux系统安全性的措施

L inux系统的安全取决于系统管理员如何来管理它。本文探讨了一系列可以增强安全性的技巧与策略 ,包括 :系统安装原则、BIOS安全、口令安全策略、设计帐户自动注销功能、文件系统和日志安全策略、使用 SSH及 TCP-WRAPPERS,隐藏系统信息、删除所有特殊帐户、关闭控制台程序、限制系统中的 SUID/ SGID程序等。本文最后向 L inux系统管理员提出了一些安全管理方面的建议     

Comparing FTTH access networks based on P2P and PMP fibre topologies

There is an ongoing discussion in the market which Next Generation Access (NGA) architecture best suits future needs and which investment and cost differences exist. The discussion can be subsumed as P2P vs. GPON, which is somewhat misleading as this article reveals. The discussion is driven by the fact that the high capital cost and the long asset life time of fibre mean that the technology choices made today will dominate the opportunities for telecommunication business of all market players, incumbents, competitors, content providers and business and residential users for many years in the future.The paper analyzes the cost and other differences between Fibre-to-the-Home (FTTH) access network architectures and their related different wholesale approaches by using the well-known and understood steady state approach applied in other NGA analyses in the past. In addition to the steady state analysis a dynamic cost evaluation is included taking into account the different investment behaviour of the FTTH architectures over time. The results describe investment and cost differences between architectures, incumbents and wholesale based competitive operators. The analysis has been performed for different geotypes (clusters) of decreasing population density in a representative European settlement structure.     

CIS与现代企业管理美学

概括性介绍了 ＣＩＳ（Ｃｏｒｐｏｒａｔｅ Ｉｄｅｎｔｉｔｙ Ｓｙｓｔｅｍ）的三大基本组成，并阐述了它与现代企业管理密不可分的相互联系及所处的举足轻重的地位，指出导入ＣＩＳ是现代企业谋求发展的重要手段。     

Divergent patterns of engagement in Internet standardization: Japan,Korea and China

This article analyzes the engagement of Japanese, Korean and Chinese participants in the development of Internet standards at IETF on the basis of four quantitative metrics: attendance, patenting, authorship and leadership. The results are strikingly divergent. Japanese involvement in Internet standardization began early and Japan was, for many years, second only to the U.S. in terms of IETF participation. Though Japanese participation has declined since the early 2000s, Japan remains a major contributor to IETF standardization. Korean involvement in IETF has always been significant, but below the levels of Japan and major European countries. Korean participation in IETF has also declined over the past decade, and has been dominated by one firm, Samsung. Though meaningful Chinese involvement in IETF did not begin until the mid-2000s, it has rapidly expanded in recent years. Today, China is a major player in numerous areas of Internet standardization in terms of three metrics (participation, patenting and leadership), and is rapidly gaining in terms of document authorship as well. Most of China׳s recent IETF involvement can be attributed to Huawei, though other Chinese firms have recently begun to increase their participation in the organization. Thus, contrary to some views that China׳s engagement with standardization is primarily one of indigenous innovation and “catching up”, China׳s experience with IETF demonstrates deliberate and effective engagement with a major Western standards-development organization on its own terms.     

快速成形技术的应用及热点分析

基于快速成形技术的原理,展示了快速成形技术在快速模具制造、金属零件直接成形、反求工程等领域的广泛应用,总结了快速成形制造技术研究的热点,即研发新材料和新设备、提高成形精度、建立RPM的反求工程系统、建立成形技术的统一标准和扩大成形技术的应用领域。     

Whose Image is it Anyway?: Some Considerations of the Curricular Importance of Subject Image in Secondary School Design and Technology Education

This paper explores the idea that a sense of school subject image is a necessary feature of curriculum management and a potent force for change. The discussion centres on the view that all school subjects have an image and that if those intimately involved with the subject do not control the image then someone else does! In such circumstances the image is the product of past encounters and old euphemisms and is unlikely to hold the changed realities.The UK developments in Design and Technology education (the term Design and Technology is used to denote the school subject defined under this heading by the UK National Curriculum, 1995) have created something of an image problem which has interesting international parallels. Some of these problems are due to clearly discernible internal tensions and an ambiguous relationship with other subject areas.Through greater attention to subject image internal controversies might be acknowledged and resolved, relationships with other subject areas can be more meaningfully understood and practitioners can be helped to make sense of curriculum change.     

Indigenous peoples’ nutrition transition in a right to food perspective

In indigenous communities the nutrition transition characterized by a rapid westernization of diet and lifestyle is associated with rising prevalence of chronic disease. Field work and literature reviews from two different policy environments, Argentina (Jujuy) and Canada (Nunavut), identified factors that add to indigenous peoples’ disease risk. The analytical framework was the emerging human right to adequate food approach to policies and programmes. Indigenous peoples’ chronic disease risk tends to increase as a result of government policies that infringe on indigenous peoples’ livelihoods and territories, undermining their economic system, values and solidarity networks. Policies intended to increase food security, including food aid, may also fuel the nutrition transition. There is a need to explore further the connection between well-intended policies towards indigenous peoples and the development of chronic diseases, and to broaden the understanding of the role that different forms of discrimination play in the westernization of their lifestyles, values and food habits. Food policies that take due account of indigenous peoples’ human rights, including their right to enjoy their culture, may counteract the growth of chronic disease in these communities.     

Diffusion and usage of public e-services in Europe: An assessment of country level indicators and drivers

We analyze the state of the art of indicators on e-government, e-health, e-procurement and e-participation. We survey the main methodological properties of these indicators, and highlight their heuristic potential. Further, we address empirically the issue of the explanation of the availability scores, i.e. how the supply of the various e-services in each country is affected by political, institutional and socio-economic differences, and is followed by actual usage. The econometric analysis uncovers the importance of broadband penetration and higher education as drivers for most of the types of e-services and users (citizens and businesses). Moreover, a corruption-free and agile public sector proves to be an important pre-condition for more effective supply and usage. Despite data limitations and the complexity of the underlying diffusion phenomena, our study is the first truly longitudinal contribution aimed at disentangling the common drivers of such an important phenomenon – the e-services availability and usage across European countries. As such, this work appears useful to inform the policy debate and practice, in a phase characterized by a prospective reorientation of the public e-services provision and policy agenda.     

一种高精度的频率标准比对系统

频率标准源可以提供精确的标准频率,在测定频率标准源的各项性能指标时,要求测试系统必须具有很高的比对精度。所设计的频率标准比对系统采取多级倍频 混频方式使频率偏差逐级扩大后再测量,从而避免了直接进行高次倍频的困难,提高了测量精度,可以对高精度的频率标准的准确度、长短期频率稳定度进行快速测量,是一种高精度时畴参数测量系统。     

A strategic skill based model of supplier integration and its effect on supply management performance

Supplier integration is a tool to help organizations gain competitive advantage. Strategic supply management skills and the supply management function's perceived status are hypothesized as antecedents to supplier integration leading to supply management performance. The sample for this study includes 152 executive level supply management professionals. The empirical results suggest that strategic skills and perceived status are essential antecedents to supplier integration and subsequent performance. Further, the relationship between strategic skills and performance is mediated by supplier integration. Results of a dominance analysis also suggest which strategic skills are most likely to explain status integration, and performance. These findings have significant implications for supply management theory and practice.