重量法测定水中硫酸盐含量的不确定度评定

按照国家标准GB11899-89中的方法进行了水中硫酸盐含量的测定,运用测量不确定度评定与表示的理论,对影响测定结果的各不确定度来源进行了分析,分析了用重量法测定水中硫酸盐含量的不确定度,对测量结果的不确定度进行了评定和表述。     

卡尔费休库仑法测定熔结环氧粉末中水分含量的不确定度评定

对卡尔费休库仑法测定熔结环氧粉末中水分含量实验方法进行了不确定度评定,分析了测定过程中带来不确定度分量的主要来源。对不确定度分量进行了计算评定,得出扩展不确定度为0.009%,水分含量测定结果可表示为:w(FBE)=0.198%±0.009%(k=2)。测定结果不确定度的主要来源是卡尔费休试剂标定产生的不确定度分量,其次是样品的重复性测定带来的不确定度分量,而天平的灵敏度则是标定卡尔费休试剂不确定度的主要来源。     

油田化学剂有机氯含量不确定度评定

本文通过分析氧燃烧微库仑法测定油田化学剂有机氯含量实验过程,对有机氯含量测定结果的不确定度进行了评定。不确定度主要来源:样品称量、燃烧定容及样品有机氯含量测定产生的不确定度。分析和量化各不确定度分量,测量的重复性及样品进样体积引起的不确定度贡献最大。     

乙酸乙酯蒸发残渣不确定度的评定

文章对乙酸乙酯蒸发残渣的不确定度进行了检测和评定。实验过程中充分考虑到不确定度的来源,建立乙酸乙酯蒸发残渣不确定度数学模型,分析了测量不确定的计算步骤和计算方法,通过对整个测定过程中所产生的各不确定度分量的分析和计算,求出了扩展不确定度。     

红外吸收法测定煤中氢含量的不确定度评定

全面介绍了采用红外吸收法对煤中氢的不确定度评定方法,应用统计学理论对其不确定度的产生原因进行分析,包括由各种随机因素产生的不确定度分量、天平引起的不确定度、煤有证标准物质的标准值不确定度引起的不确定度、工作曲线回归方程引入的标准不确定度、检测设备引入的不确定度、Mad重复测定引起的不确定度。分析测量过程各不确定度分量对总不确定度的影响,确定测定结果的置信区间。给出煤中氢的含量及其置信区间为4.10%±0.014%。     

水中COD测量不确定度的评定

建立了水中COD测定的不确定度模型,并给出了各不确定度分量的灵敏度系数。从模型可见影响COD测量不确定度值的主要因素来自于硫酸亚铁铵浓度、水样滴定消耗硫酸亚铁铵、空白滴定消耗硫酸亚铁铵和水样移取等引进的不确定度分量。计算了各不确定度分量值并给出了扩展不确定度。     

气相色谱法分析天然气和类烃化合物组分测量结果不确定度评定研究

针对用气相色谱法测定天然气和类烃化合物组分含量,建立了天然气含量测定的数学模型,分析了影响测定结果不确定度的来源,并结合实例评定了其测量不确定度,对提高分析结果准确度具有指导意义。     

矿石中铁量测定的不确定度分析

目的：介绍矿石中滴定法测定全铁的结果不确定度评定方法,为建立有效的质量控制方法提供科学依据。方法：确定和计算测定过程各不确定度分量,最后整体合成。结果重铬酸钾滴定法测定矿石中铁的不确定度为0.43%。结论：本方法评定过程合理,步骤清晰,不重复和遗漏。     

水中钙镁离子测定的不确定度评定

根据GB/T15452-2009《工业循环冷却水中钙镁离子的测定EDTA滴定法》的方法对样品的水中钙镁离子进行了测定,根据化学分析项目建立数学模型,对测定结果的不确定度进行评定。用测量不确定度表示检测结果是当前国际上约定做法,如何对测量结果不确定度进行合理评定,一直是困扰检测实验室的一个难题。作者依据测量不确定度的评定原则,通过实例,简要地阐述了滴定法测量不确定度评定方法。     

钻井液用聚丙烯酰胺钾盐中钾含量测定的不确定度评定

"测量不确定度"是当前国际上表示检测结果的通用做法,如何对测量结果的不确定度进行合理的评定,是一直以来困扰检测实验室的一个难题。依据测量不确定度的评价原则,首先通过对四苯硼钠、滴定度等一系列可能产生不确定度的分量进行计算,最后合成钾含量测定的不确定度。对钻井液用聚丙烯酰胺钾盐中钾含量测定的不确定度进行了评定,对钻井液化学剂的准确检测具有借鉴意义。     

使用气相色谱／质谱测定汽油中元素硫含量的不确定度评定

使用气相色谱／质谱测定汽油中元素硫含量,采用样品直接进样和外标法定量,该分析方法简单、快速、灵敏,且无干扰。根据不确定度的传播规律,对所用标准曲线、有证标准样品、称重、合格的玻璃器皿、测量重复性等不确定度来源进行分析评定,其中由标准曲线上求元素硫含量时所产生的不确定度分量最大,其次是测量重复性,这两项是该法测定结果不确定度的重要来源,标准溶液浓度所产生的不确定度分量较小。置信度为95％时,高、低浓度样品元素硫含量的扩展相对不确定度分别为6．4％和4．2％。     

Convergence between telecommunications and other media: How should regulation adapt?

The paper examines the regulatory issues raised by technological convergence between telecommunications and other media. Market uncertainty for broadband services has gone hand in hand with both uncertainty over how to supply those services and a regulatory framework that will facilitate growth in the sector, ensure a competitive market and provide the necessary protections for consumers and the public. Development of the information market should be determined primarily by market forces. Intervention may be justified but a clear distinction needs to be drawn between regulation in the public interest and regulation to protect against market failure.     

液体腰轮流量计示值误差测量结果的不确定度评定

结合中国石油长庆油田分公司原油流量计量的实际,利用测量不确定度评定的知识,通过建立数学模型、分析各输入量的标准不确定度、合成标准不确定度及扩展不确定度、给出测量不确定度报告,以达到对液体腰轮流量计示值误差测量结果的不确定度评定的目的。     

The effectiveness of contractual and trust‐based governance in strategic alliances under behavioral and environmental uncertainty

Research summary: We examine the interplay of behavioral and environmental uncertainty in shaping the effectiveness of two key governance mechanisms used by strategic alliances: contractual and trust‐based governance. We develop and test hypotheses, using a meta‐analytic dataset encompassing over 15,000 strategic alliances across 82 independent samples. We find that contractual governance works best under low to moderate levels of behavioral uncertainty and moderate to high levels of environmental uncertainty, while it is detrimental to alliance performance when both types of uncertainty are low or high. Trust‐based governance is most effective at high levels of behavioral uncertainty and low levels of environmental uncertainty. It suffers a large loss of usefulness at high behavioral uncertainty as environmental uncertainty increases. Managerial summary: Strategic alliances allow firms to gain greater efficiency and create value. Yet, many such alliances fail because they are not able to deal with the twin challenges posed by behavioral and environmental uncertainty. Findings from our meta‐analysis imply that under conditions of high behavioral uncertainty and low‐to‐moderate levels of environmental uncertainty, the use of trust‐based governance alongside contractual governance might enhance the latter's effectiveness. The combined effectiveness of contractual and trust‐based governance under high levels of both behavioral and environmental uncertainty is not obvious. When both behavioral and environmental uncertainty are high, contractual governance hurts alliance performance while trust‐based governance does not function at its best either. Under these conditions, it might be better for firms to turn to hierarchy or vertical integration. Copyright © 2015 John Wiley & Sons, Ltd.     

The effect of uncertainty and asset co‐specialization on governance in biotechnology alliances

We explore transaction cost economics (TCE) and real option (RO) rationales for alliance governance and find the predictive power of each depends upon the type of uncertainty confronted. Our review of alliance activity from 1995 through 2000 for 642 alliances confirms that governance is influenced directly by partner, task, and technological uncertainty and by interactions among asset co‐specialization, partner uncertainty, and task uncertainty. Consistent with TCE, co‐specialized assets increased the likelihood of hierarchical governance. Partner and task uncertainty increased this effect. Consistent with RO, we find technological uncertainty decreased the likelihood of hierarchical governance. Copyright © 2005 John Wiley & Sons, Ltd.     

Managing the Sources of Uncertainty: Matching Process and Context in Software Development

There is increasing interest in the literature about the notion of a contingent approach to product development process design. This interest stems from the realization that different types of projects carried out in different environments are likely to require quite different development processes if they are to be successful. Stated more formally, a contingent view implies that the performance impact of different development practices is likely to be mediated by the context in which those practices operate. This article provides evidence to support such a view. Our work examines whether projects in which the development process matches the context achieve superior performance. We focus on two sources of uncertainty that generate challenges for project teams: platform uncertainty, reflecting the uncertainty generated by the amount of new design work that must be undertaken in a project; and market uncertainty, reflecting the uncertainty faced in determining customer requirements for the product under development. We develop hypotheses for how these sources of uncertainty are likely to influence the relationships between a number of specific development practices and performance. We then test these hypotheses using data from a sample of 29 Internet software development projects. Our results provide evidence to support a contingent view of development process design. We show that in projects facing greater uncertainty, investments in architectural design, early technical feedback, and early market feedback have a stronger association with performance. The latter relationships are influenced by the specific sources from which this uncertainty stems: platform uncertainty mediating the impact of early technical feedback and market uncertainty mediating the impact of early market feedback. Our results also indicate that while greater uncertainty is associated with making later changes to a product's design, this practice is not associated with performance. Our findings suggest that managers carefully must evaluate both the levels and sources of uncertainty facing a project before designing the most appropriate process for its execution. In particular, they should explore the use of specific development practices based upon their usefulness in resolving the specific types of uncertainty faced. Importantly, these decisions must be made at the start of a project, with purposeful investments to create a process that best matches the context. Reacting to uncertainty ex‐post, without such investments in place, is unlikely to prove a successful strategy.     

重量法测定钻井液用褐煤树脂水分含量不确定度分析

测量不确定度是当前国际上表示检测结果约定的做法,一个完整的测量结果,除了应给出被测量的最佳估计值外,还应同时给出测量结果的不确定度。对重量法测定钻井液用褐煤树脂水分含量的不确定度进行了分析评估,找出了影响不确定度的因素。当褐煤树脂水分含量为10.32%时,测量结果的扩展不确定度为0.19%（k=2）。     

Entry in the presence of dueling options

This paper investigates the influence of industry uncertainty on the decision by established firms to enter a new industry. Specifically, we examine the tension between the option to defer , which discourages entry in the presence of uncertainty, and the option to grow , which may encourage entry in the presence of uncertainty when there are early mover advantages. Empirical analysis on data from a broad array of industries revealed that the effect of uncertainty on entry is not monotonic. Our findings are the first to find support for the nonmonotonic effect of uncertainty that has only recently emerged in theoretical treatments of real options theory, and amplify the importance of considering both the option to defer and the option to grow when contemplating entry. Furthermore, we found evidence that the relationship between uncertainty and entry is moderated by: (a) irreversibility, which influences the value of the option to defer; (b) the total value of growth opportunities; and (c) early mover advantages, which magnify the value of growth options. Copyright © 2003 John Wiley & Sons, Ltd.     

加热炉反平衡热效率的不确定度分析

建立了石化工艺加热炉反平衡热效率测算的不确定度分析数学模型，给出了分析过程和计算式，以实例计算，详细分析了影响测算结果的不确定度因素，指出了降低不确定度的方向，利用Excel软件编程简化了计算过程。