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NHD溶剂NHD是一种新型高效脱硫脱碳溶剂,主要成分是聚乙二醇二甲醚的同系物,分子式为CH3-O-(C2H4O)n-CH3,式中n=2~8。平均分子量为250~270。NHD与国外称为Selexol的溶剂性能相近,但分子分布、应用性能优于selexo... 相似文献
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染料中间体四甲基(四乙基)米氏酮的研究进展 总被引:1,自引:0,他引:1
四甲基米氏酮,英文名Michler'sKetone,化学名4,4'-双(二甲基氨基)二苯甲酮。分子式为〔CH3)2NC6H4〕2CO,熔点174℃~176℃,纯品为黄色结晶,常因不纯显深兰色,溶于苯、热酒精、乙醚、盐酸水溶液,不溶于水。四乙基米氏酮,英文名4,4'-Bis(diethylamino)benzophenone,中文化学名为4,4'-双(二乙基氨基)二苯甲酮,分子式为〔(CH3CH2)2NC6H4〕2CO,熔点94°~95℃。与四甲基米氏酮类同,因不纯显深兰色,溶于苯、热酒精、乙醚… 相似文献
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本文介绍了一套应用于矿床技术经济评价的软件系统-U ASS V1.0。该系统全部采用Turbo pascal编程,在配有EGA或VGA等图形卡的IBM PC及其兼容机上运行,使用PC-DOS和UCDOS。 相似文献
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CO2质量及其在包装上的运用张鹏程随着国民经济的迅速发展,我国工业液体CO2在工业和食品领域内得到广泛的应用,特别是饮料和包装业蓬勃发展,使食品添加剂级的CO2得到大量使用,从而促进了CO2生产量的大幅度提高,随之也带来了两个问题,即价格和纯度质量问... 相似文献
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果蔬采摘后仍然进行着呼吸作用和蒸发作用。呼吸作用消耗养分,吸收O2,呼出CO2,产生呼吸热。果蔬的呼吸作用要受到包装环境温度、气体(O2、CO2)浓度的影响。温度越高,O2浓度越高,CO2浓度越低,呼吸强度就越强,反之呼吸强度越弱。最常见果蔬保鲜的方式有低温冷藏和自然气调两种。本文仅就果蔬的呼吸作用,从其影响因素—温度、气体浓度出发,探讨这两种保鲜方式的设计计算理论。一、果蔬呼吸机理实验表明,果蔬的呼吸作用分解其养分,使其干物质(C6H12O6)的含量达到一定的低限,便失去风味,丧失食用价值。这一最低线就是… 相似文献
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为了更准确地反映刚性桩复合地基的工作状态,提高实际工程质量,以路堤下CFG复合地基为研究对象,在基本假定的前提下,分别建立类端承桩复合地基和类摩擦桩复合地基的力学模型.分析导出CFG桩复合地基工作的受力平衡条件及变形协调条件,对路堤下CFG桩复合地基桩土应力比计算公式进行修正,并对桩土应力比的影响因素进行分析.以相关文... 相似文献
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Arthur R. Burgess 《战略管理杂志》1982,3(1):53-65
Various methods are in use for the ‘top down’ assessment and comparison of the future profitabilities of businesses. The most advanced is the PAR equation of the PIMS programme, which combines quantitative evaluations of the average effect of various business characteristics on profitability. However it is not a true model in the OR sense being essentially a linear regression equation. The proposed new approach is a first attempt to combine the characteristics in a way which models the bargaining of customers with suppliers who are in competition for the supply of a bulk product. All the constants in the resulting non-linear equation (called 5C) are meaningful in marketing or production terms. The model is in a preliminary non-optimized state, but seems to offer opportunities for ongoing development. It is in this spirit that it is offered for discussion. 相似文献
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《Food Policy》2014
In this article, we employ a discrete choice experiment to examine preferences for functional dairy product attributes and willingness-to-pay estimates for consumers in Germany. We estimate preference heterogeneity by linking stated preference choice data not only to socioeconomic characteristics but also to attitudinal statements in a latent class framework. The empirical results indicate the existence of class-specific preference heterogeneity based on the consumers’ attitude towards functional foods, emphasizing the importance of attitudinal data in explaining consumers’ choice behavior. Our estimates demonstrate that within a class, consumers’ preferences are in accordance with their responses to attitudinal statements, that is functional food skeptics prefer non-functional dairy products, while functional food advocates have a negative preference for non-functional dairy products. The findings also show that all consumers place high value on dairy products enriched with known functional ingredients such as omega-3 fatty acids. 相似文献
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Industrial relations and welfare state are interrelated. On the basis of time‐series data for 20 OECD countries, this paper discusses and tests the impact of industrial relations on social expenditures, including ‘social pacts’ as a means of combining wage moderation and welfare state reforms. The findings suggest that industrial relations have an impact mainly through the differential effects of distinct bargaining systems: a minor impact results from their externalities. The major impact ensues from their differing degrees of politicization, leading to higher expenditures in the case of peak‐level arrangements, as compared to more decentralized systems. Hence, the widely assumed potential of social pacts for welfare state reforms has been exaggerated. 相似文献
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卷筒纸印刷机的速度-张力耦合,是实现印刷机速度-张力精确控制的一个难题。为了精确控制印刷机的速度-张力,首先建立卷筒纸印刷机机电系统状态方程模型,依据状态反馈动态解耦控制理论,进行解耦控制。仿真结果表明,动态解耦控制在速度-张力控制中具有一定作用,为卷筒纸印刷机速度-张力的精确控制提供了一种有效方法。 相似文献
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Economic feasibility analysis of flexible material handling systems: A case study in the apparel industry 总被引:2,自引:0,他引:2
James B. Dai 《International Journal of Production Economics》2012,136(1):28-36
Flexible material handling systems (MHS) have been widely used to enhance productivity involved with product proliferation, and thus far, only fixed-track MHSs such as Eton systems in the apparel industry are commonly used. This paper explores the economic feasibility of a flexible MHS using free-ranging automated guided vehicles (AGV) with a local positioning system (LPS) for the apparel industry. A component-based and modified activity-based costing methodology is proposed to estimate the additional cost of adopting flexible MHSs, and then the internal rate of return (IIR) and payback periods are applied to evaluate the project economic performance. Results show that adopting flexible MHSs has a promising IIR which is larger than 30%. 相似文献
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The concept of equivalent annual annuity (EAA) has long been used as a method of costing recovery of invested capital and the required return on invested capital over the productive life of a capital project. Academic texts almost universally use EAA methodology with level payment streams (annuities) to allocate capital costs. We develop a methodology for allocating capital costs evenly over each unit of production for projects with anticipated non-level production. This methodology uses a modified EAA approach that allows non-level annuity payment streams. Capital cost allocation is an important component in computing the value of extracted minerals for severance tax purposes; however, many firms and state and federal agencies use ad hocdepreciation schedules to allocate these costs. Ad hocdepreciation methods such as modified accelerated cost recovery system (MACRS) may be appropriate for income tax purposes but are inconsistent with commonly found requirements that severance taxes “shall be assessed on the wellhead or mine mouth fair market value.” The modified EAA approach provides a straightforward alternative that is based on sound financial methodology. 相似文献