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1.
《中国测试》2016,(5):56-60
建立碘离子溶液标准物质的制备方法及不确定度评定模型。采用质量-容量法制备特性量值为10μg/m L的碘离子溶液标准物质,该标准物质以高纯碘化钾为原料,经IC、ICP和ICP-MS 3种方法分析检测扣除其杂质,并且通过干燥减重法扣除其水分含量,精确测定碘化钾的纯度。制备的碘离子溶液标准物质均匀性和稳定性良好,定值结果的相对扩展不确定度为U=2%(k=2),有效期限为12个月,与同类标准样品GSB 04-2834-2011进行比对分析,结果显示,在规定的不确定度范围内量值具有一致性。该碘离子溶液标准物质可用于环境水质、食品安全等领域的安全检测及相应分析方法的确认与评价。  相似文献   

2.
采用重量-容量法,配制了化学需氧量溶液标准物质,利用一级标准物质进行比较定值,并对溶液标准物质进行了均匀性检验和稳定性考察。对定值的不确定度进行了评定。化学需氧量溶液标准物质的定值结果为2000mg/L,扩展不确定度为:Urel=2%,k=2。  相似文献   

3.
本课题研制了乙腈中展青霉素的溶液标准物质1种,并已成功申报为国家二级标准物质(GBW(E)100674)。该溶液标准物质以展青霉素纯度国家二级标准物质(GBW(E)100673)为原料,采用重量容量法配制。依据JJF1343-2012《标准物质定值的通用原则及统计学原理》的要求,本研究采用液相色谱法对乙腈中展青霉素溶液标准物质进行均匀性、短期稳定性和长期稳定性的评价。定值不确定度包含原料纯度、溶液配制、均匀性、短期稳定性和长期稳定性五个方面引入的不确定度。最终,该溶液标准物质GBW(E)100674的定值结果为100μg/m L,不确定度为2%。本研究研制展青霉素溶液标准物质的量值具有溯源性和准确性,可以支持国家食品安全检测的需要。  相似文献   

4.
李云巧  崔婷  王道 《计量学报》2006,27(1):77-80
介绍了磷溶液标准物质的研制。选择磷酸二氢钾为原料,经提纯后,配制成质量浓度为1000μg/mL的磷溶液标准物质。采用准确、可靠并能溯源的磷钼酸喹啉重量法进行定值、均匀性检验及稳定性检验。对影响测量不确定度的因素进行了分析,全面评定了标准物质的不确定度。研制的磷溶液标准物质,均匀性良好,扩展不确定度为0.5%(k=2),稳定性达2年。  相似文献   

5.
苯系物溶液标准物质的研究   总被引:2,自引:0,他引:2  
曹文祺  何雅娟  纪洁 《计量学报》2003,24(3):240-244
论述了苯系物溶液标准物质的研究工作 ,系统地介绍了标准物质原材料的选择、特性量值的测量方法、标准物质的制备方法、均匀性检验、稳定性考察以及定值测量。对样品的均匀性、测量的分散性及其他因素引入的不确定度分量分析和确定后 ,给出了整个测量过程不确定度的合成结果。对气相色谱法和液相色谱法所得到的实验结果进行了统计分析 ,其均匀性符合F检验和T检验 ,满足标准物质的技术规范。对苯系物溶液标准物质的稳定性进行了 2年的考察 ,证明该标准物质是稳定的 ,浓度值的不确定度为 2 8%。苯系物溶液标准物质已被批准为国家一级标准物质  相似文献   

6.
介绍了氯化钾电导率溶液标准物质的研制方法,采用与一级标准物质比较定值的方法对该标准物质进行了定值,利用高精度电导率仪对定值结果进行了验证,同时对该标准物质进行了均匀性检验和稳定性考察。氯化钾电导率溶液标准物质的定值结果为1408μS/cm,扩展不确定度为:Urel=0.6%,k=2。其均匀性和稳定性检验结果表明,该标准物质符合国家二级标准物质的技术要求。  相似文献   

7.
研制了液相色谱-质谱联用仪(LC-MS)校准用甲醇水中咖啡因溶液标准物质并进行不确定度评定。以咖啡因纯品、色谱级甲醇和实验室一级用水为原材料,利用质量平衡法对咖啡因纯品进行纯度核验,利用基准方法重量—容量法配制浓度9.94 mg/L甲醇水中咖啡因溶液标准物质。采用液相色谱法对9.94 mg/L甲醇水中咖啡因标准溶液和国家二级标准物质GBW(E)130453进行量值比对,并对溶液标准物质的均匀性、短期稳定性和长期稳定性进行考察。结果表明研制的9.94 mg/L的甲醇水中咖啡因溶液标准物质的均匀性和稳定性良好,相对扩展不确定度为2%(k=2),有效期为12个月。  相似文献   

8.
选择氯化钡为原料,经纯度分析后,配制成目标浓度为20 mg/mL的钡溶液标准物质.采用BaSO4重量基准法与仪器分析相结合的方法进行均匀性检验、稳定性监测与定值.对影响测量结果的因素进行了系统研究,将各影响量降至最低水平,利用仪器分析法准确测定各影响因素的量值,并逐一进行修正;全面进行了测量不确定度评定.研制的钡溶液标准物质不确定度为0.08%(k=2),稳定性达1年.  相似文献   

9.
采用二甲基亚砜(DMSO)作为冻干标准物质的溶剂,以重量法准确配制维生素K_1/DMSO溶液,再进行分装、冷冻干燥,经定性分析、定值分析、均匀性检验、稳定性考察和不确定度评定,研制了维生素K_1冻干标准物质。以维生素K_1纯度标准物质溶液为校准品,对得到的冻干物质进行了高效液相色谱法定值分析,冻干标准物质的准确定值结果为0.96 mg/mL,相对扩展不确定度为7%。建立的维生素K_1冻干标准物质研制方法,对于临床检验中维生素K_1的准确测定和相关疾病的正确诊断治疗以及维生素K_1长期保存具有重要意义。  相似文献   

10.
文章以氟化钠标准物质为原料,超纯水为溶剂,采用重量-容量法制备水中氟离子溶液标准物质,介绍了水中氟离子溶液标准物质的研制方法。研制的水中氟离子溶液标准物质利用离子色谱法进行检测,分别采用F检验和回归曲线法进行均匀性和稳定性检验,方差分析和线性拟合结果表明该标准物质具有良好的均匀性和稳定性。选择国家二级标准物质采用同样的检测方法进行验证,结果表明制备的标准物质的方法准确度满足要求。研制的水中氟离子溶液标准物质的定值结果为1 000 mg/L,相对扩展不确定度Urel=1%(k=2)。该标准物质量值准确,且具有溯源性,可用于水中氟离子测量过程的质量控制及分析方法的确认和评价。  相似文献   

11.
In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.  相似文献   

12.
We associate a variety of innovations with the term "Industry 4.0". The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...  相似文献   

13.
A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.  相似文献   

14.
ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.  相似文献   

15.
16.
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……  相似文献   

17.
A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.  相似文献   

18.
Al2O3-ZrO2 nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.  相似文献   

19.
The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……  相似文献   

20.
Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.  相似文献   

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