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电感耦合等离子体发射光谱法( ICP- AES)被广泛使其广泛应用于地质矿产分析测试中,是目前稀土元素( REES)的主要分析测试手段,ICP- AES具有动态线性范围宽、多元素同时测定等优点,同时具有优越的分析特性。我国以电感耦合等离子体发射光谱法为主体建立了一些标准的数据分析方法,如GB/T 17417.1-17417.2-2010等。本文从测定稀土在矿石中不同赋存形态的角度出发,对我国电感耦合等离子体发射光谱法进行了新进展分析。 相似文献
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采用电感耦合等离子体原子发射光谱法(ICP-AES)测定了铝锰铁中杂质元素。采用酸溶解试样,溶解后,用ICP-AES测定磷等元素,铝锰铁中磷检出限为0.02μg/mL,采用基体匹配与背景扣除法消除基体对待测元素的光谱干扰,确定了最佳实验条件。方法已成功地应用于铝锰铁中杂质元素的测定,试验证明,本方法简便、快速、准确,分析结果满意 相似文献
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铜元素在食品中广泛存在,是人体不可或缺的微量元素,如果缺乏铜会对人体造成很大的危害,导致神经系统失调,大脑功能发生障碍。本文综述了分光光度法、原子吸收光谱法、电感耦合等离子体发射光谱法等测定铜含量的方法。 相似文献
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《化工管理》2019,(31)
采用电感耦合等离子体质谱仪(ICP-MS)同时测定生活饮用水地表水源地水质铜、锌、镉、铅、铁、锰、钼、钴、铍、锑、镍、钡、钒、钛、铊15种金属元素的含量。充分预热仪器后,用质谱调谐液调整仪器指标使其达到良好测定状态,选取Li6、Sc、Ge、Rh、In、Bi作为内标。各测定元素相关系数均在0.999以上,检出限在0.01~0.73μg/L之间,样品全程序空白和实验室空白均低于检出限,有证标准物质测定结果均在标准要求的范围内,实际样品加标回收率72.0%~118%,平行样品相对偏差<20%。结果表明,该方法简便、快速、适用于饮用水源地水质多种重金属元素同时测定。 相似文献
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《Telecommunications Policy》2014,38(5-6):415-425
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. 相似文献
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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. 相似文献
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A strategic skill based model of supplier integration and its effect on supply management performance 总被引:1,自引:0,他引:1
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. 相似文献
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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.
Bradley J. Koch , PhD, is a Teaching Fellow at Nanyang Technological University. His research is focused on China where he studies a variety of topics including cognitive institutional environments, foreign direct investment, social capital, gender, and Internet and society. Pamela Tremain Koch , PhD, is an Assistant Professor in the School of Communication and Information, Nanyang Technological University. Her current research is focused on organisational communication, conflict management, internet, work, and society as well as information communication technologies and development. 相似文献
Bradley J. KochEmail: |
Bradley J. Koch , PhD, is a Teaching Fellow at Nanyang Technological University. His research is focused on China where he studies a variety of topics including cognitive institutional environments, foreign direct investment, social capital, gender, and Internet and society. Pamela Tremain Koch , PhD, is an Assistant Professor in the School of Communication and Information, Nanyang Technological University. Her current research is focused on organisational communication, conflict management, internet, work, and society as well as information communication technologies and development. 相似文献
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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. 相似文献
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倪卫高 《石油化工技术经济》2011,27(1)
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. 相似文献
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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。 相似文献
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《Food Policy》2014
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. 相似文献