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%。     

抽油杆（H级）抗拉强度测量结果不确定度的评定

为评定抽油杆抗拉强度的测量不确定度，以H级抽油杆为例，建立不确定度计算的数学模型，确定影响试验结果的各项因素，计算各因素所带来的不确定度分量，求出合成标准不确定度。从而得出扩展不确定度，最终给出抽油杆抗拉强度测量结果的表达式。     

测量不确定度估算中协方差的两类评定

论述了当测量不确定度评定中出现相同原因导致某些不确定度分量相关时,用Ａ类方法计算的实质,同时提出了采用Ｂ类方法的可能性,指明按系统效应导致的分量与随机效应导致的分量的大小比,用Ｂ类方法计算相关系数的具体步骤。给出了一般情况下的计算结果。     

建标报告中有关不确定度评定的若干问题

建标报告中的总不确定度只包含计量标准与比较装置的不确定度,既可以分别给出,也可以给出这两部分的合成不确定度。其中不包括被校准或被检定测量仪器所导致的不确定度。所谓计量标准的测量不确定度,则可包括某一种典型的被校准或被检定的仪器所导致的分量。     

利用质量控制和方法确认数据评定汽油中MTBE含量的测量不确定度

按照RB/T 141—2018《化学检测领域测量不确定度评定利用质量控制和方法确认数据评定不确定度》,在期间精密度测量条件下,基于质量控制结果和方法确认数据,接受测量系统正态性与独立性假设,合并期间精密度不确定度分量uR′和偏倚不确定度分量ub,给出样品水平下的合成标准不确定度uc和扩展不确定度U,为检测实验室评定汽油中MTBE含量的测量不确定度提供了一种简便方法。     

蚊香烟尘量的不确定度评定

依据GB 24330-2009《家用卫生杀虫用品安全通用技术条件》附录E对蚊香烟尘量进行测定,基于JJF 1059.1-2012《测量不确定度评定及表示》对影响蚊香的烟尘量测量不确定度的各分量进行分析,并对各分量的标准不确定度进行计算和合成。通过比较各分量的标准不确定度,得出了影响蚊香的烟尘量测量不确定度的主要因素。     

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。     

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。     

标准活塞压力计检定电子式井下压力计示值误差测量不确定度评定

针对油田测试领域检定电子式井下压力计示值误差测量不确定度评定,给出了测量不确定度的评定方法.又对测量不确定度技术进行了实际应用和研究,并把有一定代表性的压力类标准装置作为研究测量不确定度对象.这成为指导检定电子式井下压力计标准装置技术报告中测量不确定度内容.     

钻井液滤液中氯离子含量的不确定度评定

依据测量不确定度的评价原则，从方法概述、确定不确定度的来源、建立数学模型、计算相对标准不确定度分量、合成相对标准不确定度、扩展不确定度等入手，通过实例详细阐述了钻井液滤液中氯离子含量测定的不确定度评定方法。     

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.     

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.     

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.     

Cost allocation of WCDMA and wholesale pricing for mVoIP and data services

This study estimates cost-based prices for wholesale voice and data services provided to 3G (WCDMA) MVNOs according to their distinct types. For estimation, 3G MVNOs are classified into different types, and the overall cost of WCDMA facilities are separated into voice and data components based on their subscriber rates, actual traffic rates, as well as efficiency consideration of traffic rates. The study then calculates cost-based wholesale prices of voice and data services for each of the 3G MVNO types. The result of this study shows that a cost-plus pricing scheme can help achieve the policy goals of the regulator, namely, lowering telecommunications tariffs and facilitating the introduction of new convergent-type services, far more effectively than the current retail-minus pricing scheme. The findings of this study may assist firms in developing business models based on 3G networks and telecom regulators in designing policies related to interconnection, mVoIP, prepaid calls, wholesale services, and network neutrality.     

Collectivism,individualism, and outgroup cooperation in a segmented China

A consistent theme in cross-cultural management research is that collectivists are more cooperative than individualists. We use Hofstede's measure for individualism–collectivism and combine it with an experimental measure of cooperation to test this relationship in China. In contrast to the established paradigm, we find that groups with higher individualistic scores are more cooperative than those groups with higher collectivistic scores. We attribute these results to groups being composed of outgroup members. In addition, we find that subjects from the more developed coastal area are more individualistic and cooperative than are subjects from inland China.

电子产品的电磁兼容性设计

首先介绍电磁兼容性的基本概念与研究领域,然后重点阐述电子产品的电磁兼容性设计与测量。     

SPYRO在烯烃原料生产方案测算中的应用

文章对SPYRO裂解模拟软件在石化企业烯烃生产原料优化方案测算中的应用进行了比较深度的概括分析.结合该软件在上海石化的实际应用,认为在劣质化原油加工份额不断增加的趋势下,SPYRO裂解模拟软件有助于石化企业在烯烃生产原料优化选择、生产计划合理安排、原油加工生产效益比较等方面为企业相关决策者提供有效地帮助.     

施工企业工程项目部的建设浅论

工程项目的一次性决定了工程项目部的一次性，而工程项目成本中心与企业利润中心地位又辱致工程项目部的临时性，在工程项目实践过程中，项目经理部的一次性在实现其功能的过程中可能会产生很多局限和负面影响，故项目部应具有相对的稳定性，在此基础上，本对工程项目部建设实践进行了初步总结并提出了建议。     

European consumer preferences for beef with nutrition and health claims: A multi-country investigation using discrete choice experiments

The European Union (EU) nutrition labelling policy aims to facilitate consumers’ food choice, stimulate innovation and facilitate the circulation of foods bearing claims across countries. However, the beef industry has not fully taken advantage of utilizing nutrition and health claims based on the EU nutrition labelling policy to differentiate beef products in the market. This study investigates consumer preferences for nutrition and health claims on lean beef steak. Two choice experiments were conducted among 2400 beef consumers in four EU countries (Belgium, France, the Netherlands, United and United Kingdom). Multinomial logit and error component models were estimated. Our results generally suggest that consumer valuation of nutritional and health claims varies across countries. In Belgium, the Netherlands and France, nutrition and health claims on saturated fat yielded higher utilities than claims on protein and/or iron, while the opposite was found among consumers in the UK. The results imply that marketing opportunities related to nutrition and health claims on beef are promising, but that different nutritional marketing strategies are necessary within different countries.     

Social media as a useful tool in food risk and benefit communication? A strategic orientation approach

Although considerable progress has been made in understanding the determinants of risk perception and in identifying the necessary components of effective food risk and benefit communication, this has not been matched with the development of efficient and appropriate communication tools. Little work has been done examining the implications of the explosion of new media and web technologies, which may offer potential for improving food risk and benefit communication. First, this study examines the views of stakeholders (n = 38) and experts (n = 33) in the food domain on the potential use of these emerging media for food risk/benefit communication. Based on in-depth interviews in six European countries (Belgium, Ireland, Italy, Latvia, Spain and The Netherlands), strengths, weaknesses, opportunities and threats (SWOT) of social media in food risk and benefit communication were identified. Second, a Strategic Orientation Round (SOR) was used to evaluate the relative importance of the SWOT components according to stakeholders (n = 10) and experts (n = 13). Results show that both stakeholders and experts confirm a future role of social media in food risk and benefit communication. Strengths as speed, accessibility and interaction make social media an interesting tool in crisis communication or issue awareness raising. Weaknesses as the lack of a filter, low trust, the risk of information overload and a communication preference for traditional media are acknowledged.