共查询到20条相似文献,搜索用时 125 毫秒
1.
目的:评定GB/T 5009.34-2003《食品中亚硫酸盐的测定》中盐酸副玫瑰苯胺法测定酱腌菜中二氧化硫含量的不确定度。方法:对盐酸副玫瑰苯胺法测定酱腌菜中二氧化硫含量测定过程中各影响因素进行分析,建立数学模型,确定影响不确定度的因素并对各个因素进行评估,以此计算各变量的不确定度和合成不确定度,最终计算扩展不确定度。结果:当酱腌菜中二氧化硫含量的测定值为98.632 4 mg/kg时,计算得到扩展不确定度为0.609 3 mg/kg,测定结果表示为(98.632 4±0.609 3)mg/kg,k=2,P=95%。结论:盐酸副玫瑰苯胺法测定酱腌菜中二氧化硫含量的不确定度主要由样液中二氧化硫的含量和平行实验结果引起。 相似文献
2.
3.
本文探讨了电感耦合等离子发射光谱法(inductively coupled plasma emission spectroscopy,ICP-OES)测定铜精矿中砷含量的不确定度评价方法。分析了整个测定过程的不确定度来源,包括测量体积、称重和重复性试验等,并对各部分不确定度分类进行了量化计算。在数学模型中引入重复性测量修正因子,简化不确定度计算过程。通过推导计算,给出了铜精矿中砷含量的扩展不确定度,为ICP-OES法测量不确定度评价方法提供了一个参考模式。 相似文献
4.
5.
6.
7.
8.
通过对火焰原子吸收分光光度法测定不锈钢中锰含量的不确定度的系统分析,阐述了测量结果不确定度主要来源于工作曲线拟合引起的不确定度、锰标准溶液及配制引入的不确定度、重复测得样品产生的不确定度,并对这些分量进行了量化计算,最后计算出合成标准不确定度和扩展不确定度。 相似文献
9.
10.
11.
12.
本文通过分析酱中食盐的测量过程,分析实验中不确定的来源,确定不确定度分量并评定,从而确认影响酱中食盐含量测量过程中的最大不确定度分量。 相似文献
13.
对GB 5009.28-2016法测定食品中苯甲酸含量的测量不确定度进行评定。该测量方法为相对测量法,本次评定以A类评定为主,B类评定为辅。对食品中苯甲酸的测定测量不确定度的评定,验证了仪器设备的精度,又是一次实验室测试能力的评定。 相似文献
14.
15.
根据JJF1059-1999《测量不确定度评价与表示》对建立液相色谱-质谱测定方法的不确定度评定方式,对糖皮质激素的测定进行不确定度分析。通过对地塞米松测定过程建立数学模型,包括对称重、溶液配制等方面,其中在方法的不确定度评定过程中,应主要考虑不确定度贡献较大的分量,从而简化实验操作步骤,提高工作效率。通过对标准曲线、称量、标准溶液配制、实验人员、环境等因素引入的不确定度进行分析,置信区间为95%时,k=2,得出不确定度结果为UC=31.40mg/mL,地塞米松含量c=(397.45±32.66)mg/mL。 相似文献
16.
Rotimi Williams Olatunji 《Journal of Promotion Management》2013,19(2):257-272
The creative repetition of the most important aspects of communications, or redundancy, is a strategy employed in the field of advertising to ensure that messages are understood and acted upon by the audience or prospects. The article shows the influence of redundancy on consumer learning. Six brand advertisements were purposively selected and analyzed for content to demonstrate the occurrence, uses, and limitations of creative repetition of messages in advertising, along with appropriate recommendations. 相似文献
18.
中国FDI配置效率的区域差异及影响因素——基于面板数据的分析 总被引:1,自引:0,他引:1
帕累托式的FDI空间配置有利于区域协调增长.本文研究表明,中国FDI配置效率的区域差异特征明显.在动态趋势方面,东部优势减弱,中部综合优势明显.在国家、区域间和区域内3个层面上,FDI配置效率影响因素各不相同.在国家层面上,市场、公共资本等因素权重较大.在区域间,区位、知识与技术、劳动力成本等因素较关键.在区域内部,各因素重要性各异. 相似文献
19.
This study identifies three perspectives of accountability in charitable organizations: agency, stewardship, and stakeholder in relation to the availability of financial information. To examine current accountability practices, 75 interviews and informal conversations were undertaken with participants in charities in New Zealand. Many of the interviewees operated under some form of stewardship milieu. They regarded the need to discharge accountability by providing financial information as a low priority. Education may provide a way to resolve this issue by advancing stakeholders’ perspectives of accountability. This could result in reduced support for charities that do not uphold a certain standard of financial information. 相似文献
20.
Economies of scale in grocery retailing in Finland 总被引:1,自引:0,他引:1
This paper considers the question of store-level economies of scale in grocery retailing. Hedonic price and cost functions are used in modelling the price and cost structure of retailers, but without making the assumption of constant mark-ups, as normally done in hedonic price studies. The main result of the paper is that store-level economies of scale do exist in grocery retailing: large stores have on average 10% lower costs per sold unit than small stores. The second major finding is that most of the benefits from scale economies are passed on to consumers: the price level of large stores is 10% lower on average than of small stores. 相似文献