能谱仪测定钛合金中钛元素含量不确定度评定

能谱仪是一种微区元素种类与含量分析的设备,是材料分析领域最常用的一种定性半定量的分析手段。本文对《GB/T17359-2012微束分析能谱法定量分析》中利用能谱仪对元素含量的测定进行了不确定度评定,考察了不确定度的主要来源并对不确定度各分量进行了评定,计算出合成标准不确定度和扩展不确定度。结果表明:合成标准不确定度为2.79%;取置信概率为95%,即k=2时,相应的扩展不确定度为:5.58%。确定了方法最大允许误差为影响测量不确定度的最主要因素。     

离子色谱法测定牛乳中硝酸盐的不确定度评定

目的:全面地分析离子色谱法测定牛乳中硝酸盐的不确定度来源及其影响因素。方法:通过建立数学模型,对测量过程中的不确定度进行逐层分析与合成,采用最小二乘法对外标曲线拟合的不确定度进行评定。结果:离子色谱法测定牛乳中硝酸盐的相对扩展不确定度为2.42%(k=2)。结论:本文不确定度的评定方法在实际工作中具有较强的实用价值。     

电子探针测定镁橄榄石中元素含量的不确定度

本文基于氧化物的ZAF修正法对典型样品进行定量分析。在得出了定量分析结果之后,分析了样品测量不确定度的来源,得出电子探针定量分析的不确定度模型,测算了每个影响因素的具体数据,最后计算出了定量结果的扩展不确定度。结果表明ZAF修正法引入的不确定度对测试结果的不确定度影响非常小,主要影响结果不确定度的因素是测量重复性引入的不确定度造成的。利用不确定度提高测试和仪器校准的准确度,可以对电子探针定量分析的后续工作提供基础和保障。     

电感耦合等离子发射光谱法与原子吸收光谱法测定铜矿石中铜的不确定度评定

采用电感耦合等离子体发射光谱法(ICP-OES)和原子吸收光谱法(AAS)对测定铜矿石中铜元素进行系统的不确定度评定。建立两种方法测定铜矿石中铜元素的数学模型,分析不确定度的来源主要包括样品称量过程使用的天平、标准工作溶液配置过程所使用的量器、标准工作曲线拟合、测量重复性及试液定容体积等引入的不确定度分量,对引入的各不确定度分量进行量化,计算出各分量的不确定度,通过合成得到测量结果的合成不确定度、扩展不确定度及测试结果的报告形式。比较ICP-OES法和AAS法分别测定3个铜矿石样品中铜的不确定度,随着试样中铜元素浓度的增加,样品不确定度伴随增大趋势,两种方法所测定铜元素结果符合分析结果的相对偏差小于允许限为合格的要求。     

电感耦合等离子体原子发射光谱法测定镍基高温合金中铂、钯含量

试样采用盐酸、硝酸和氢氟酸溶解,用电感耦合等离子体原子发射光谱法(ICP-AES)测定镍基高温合金中铂(Pt)、钯(Pd)元素。本工作中优化了仪器工作参数,对待测元素分析线进行了选择试验,考察了高温合金基体和共存元素对待测元素的影响,最终确定了分析线分别为Pt 214.424 nm、Pd 340.458 nm,选定的待测元素分析线不受基体和共存元素的干扰,基体的其他影响可以通过在校准曲线溶液中进行匹配而消除。对高温合金中铂、钯元素测量的准确度、精密度和加标回收率进行了研究,回收率在96%～110%之间,RSD≤6%。     

电感耦合等离子光谱法测定婴幼儿营养米粉中铁含量的不确定度评定

以婴幼儿营养米粉为例,根据食品安全国家标准GB5009.268-2016《食品中多元素的测定》中电感耦合等离子体光谱法(ICP-OES)测定营养米粉中的铁含量,分析测试过程中引起不确定度的因素,对涉及到的标准物质,设备仪器,玻璃器皿不确定度的来源进行详细分析和计算。通过实验研究发现,对实验结果影响最大的是标准物质溶液的配制,其引起的相对标准不确定度为0.0542;其次是标准曲线最小二乘法拟合计算浓度,其引起的相对标准不确定度为0.0215。样品称量、样品溶液定容、加标回收、样品重复测定对实验结果影响较小。该研究中ICP-OES法测定婴幼儿米粉铁含量不确定度报告为(58.3±6.9)mg/kg(k=2)。     

复杂系统参数不确定度的传递特征与理论建模

对不确定度进行推广,发展了多参数广义不确定度的概念,并对广义不确定度的基本性质进行分析。对复杂系统参数广义不确定度的传递特征进行研究并对传递特征进行分类,研究了单一子系统不确定度的传递模式和特征,传递矩阵中元素的绝对值对目标参数不确定度的计算结果有着重要影响。分析了各个子系统参数不确定度传递过程中的主要和次要作用并建立相应的判别准则。算例表明了该理论模型在研究复杂系统参数不确定度传递问题时的有效性和可行性。     

复杂系统参数不确定度的传递特征与理论建模

对不确定度进行推广,发展了多参数广义不确定度的概念,并对广义不确定度的基本性质进行分析。对复杂系统参数广义不确定度的传递特征进行研究并对传递特征进行分类,研究了单一子系统不确定度的传递模式和特征,传递矩阵中元素的绝对值对目标参数不确定度的计算结果有着重要影响。分析了各个子系统参数不确定度传递过程中的主要和次要作用并建立相应的判别准则。算例表明了该理论模型在研究复杂系统参数不确定度传递问题时的有效性和可行性。     

HPLC测定食品中山梨酸结果的不确定度评定

目的:全面地分析HPLC测定食品中山梨酸的不确定度来源与影响不确定度的因素.方法:通过建立数学模型,对测量过程中的不确定度进行了逐层分析和合成,采用最小二乘法对外标曲线拟合的不确定度进行了评定.结果:HPLC测定食品中山梨酸的相对扩展不确定度为3.2%.结论:该不确定度的评定方法在实际工作中具有较强的实用价值.     

氢化物发生原子荧光法测定空气中锑的不确定度评定

目的:建立氢化物发生-原子荧光光谱法测定工作场所空气中的锑含量及测量不确定度评定的方法。方法:样品经湿法消解,用原子荧光仪检测,应用检测不确定度评定方法对测量结果进行不确定度分析与评定。结果:该检测方法线性良好,相关系数r=0.9998,相对标准偏差为2.83%～3.63%,加标回收率为95.1%～97.7%,不确定度报告为(0.274±0.009)mg/m~3取k=2。结论:本方法用于工作场所空气中锑的测定,不确定度评定合理,结果令人满意。     

Uncertainty analysis of displacement measurement with Imetrum Video Gauge

Imetrum Video Gauge is a commercial image-based two-dimensional displacement measurement system which has been widely used. Its uncertainty analysis is presented in this paper. First, the procedure to use Video Gauge is introduced. Then, based on the measurement model, two major sources of uncertainty are identified: (1) the uncertainty associated with the calibration procedure u(C) which is composed of the uncertainty of the known length used in calibration u(L) and the uncertainty of the projection of the known length in the image u(D) and (2) the uncertainty associated with the measurement system itself u(P). Following the Guide to the Expression of Uncertainty in Measurement, the uncertainties can be quantified. In the end, 60 experiments are performed to analyze the relationship between the measurement uncertainty and the working parameters, which are working distance, acquisition frequency and focal length of the lens. In order to ensure the validity of the calculation, two calculation methods are used. The main results of this paper are as follows: (1) the displacement measurement uncertainty increases along with working distance and decreases with the increase of focal length. At the same time, the results indicate that using a longer known length in calibration can also reduce the measurement uncertainty. (2) u(C) is greatly influenced by the known length used in the calibration procedure. It can be reduced when u(L) is reduced. (3) Under the laboratory circumstances, reducing u(C) can greatly reduce the total measurement uncertainty. (4) The displacement measurement uncertainty is more sensitive to the measurement uncertainty of the known length used in calibration than the projection of the known length in the image. (5) As the working distance grows, the sensitivity to the known length is getting weaker and the sensitivity to the projection of the known length in the image is getting stronger. (6) When a longer focal length lens is used, the influence of the working distance to the sensitivity gets weaker. The reported results can help people better understand the characteristics of this system and better use the system for their own purposes.     

自校准型光谱辐亮度标准光源

针对高精度空间光学定量遥感的需求,研制了一种采用数字微镜器件的自校准型光谱辐亮度标准光源。该光源具有两种工作模式:在窄带工作模式下,由Gershun管辐射计和CAS光谱辐射计自校准;在宽带工作模式下,作为光谱辐亮度标准光源用于地面或空间遥感仪器的光谱辐亮度响应度定标。以光谱辐照度标准光源和Spectralon标准漫反射板组成光谱辐亮度标准光源为CAS光谱辐射计定标,测得自校准光源的光谱辐亮度。又以标准探测器定标的Gershun管辐射计测量自校准光源,采用迭代法得到自校准光源的光谱辐亮度。窄带模式下两种不同定标方法对自校准光源的光谱辐亮度测量结果在测量不确定度允许范围内一致。不确定度分析显示:基于标准光源和基于标准探测器的自校准光源光谱辐亮度测量不确定度分别为1.41%~2.09%和1.28%~1.61%。实验及不确定度分析结果表明,该光源可以满足高精度空间光学定量遥感的使用要求。     

α-硫辛酸中有机溶剂残留量的不确定度评定

研究了α-硫辛酸中有机溶剂残留量气相色谱定量方法的测量不确定度的评定方法。通过建立数学模型,对测量过程的不确定度来源如：样品称样量、定容体积、工作曲线、测试方法的回收率和重复性的各不确定度分量进行分析评定和量化,计算了合成不确定度和扩展不确定度,α-硫辛酸中有机溶剂残留量的GC定量结果表示为乙醚（0.252±0.006）%;k=2;异丙醚（0.092±0.002）%;k=2。本试验的不确定度主要由外标工作曲线所引起。     

Shifting Rule Modification Strategy of Automatic Transmission Based on Driver-vehicle-road Environment

Accidental or frequent shift often occurs when the shifting rule is built based on traditional two parameters (I.e., velocity and throttle), because the speed of engine varies slower than change of throttle opening. Currently, modifying shift point velocity value or throttle by throttle change rate is one of common methods, but the results are not so satisfactory in some working condition such as uphill. The reason is that these methods merely consider throttle change rate which is not enough for a car driving in driver-vehicle-road environment system. So a novel fuzzy control modification strategy is proposed to avoid or reduce those abnormal shift actions. It can adjust shifting rule by the change rate of throttle, current gear position and road environment information, while different gear position and driving environment get corresponding modification value. In order to compare the results of shifting actions, fuel consumption and braking distance, emergent braking in level road and extra-urban driving cycle(EUDC) working conditions with fuzzy shifting schedule modification strategy are simulated digitally. Furthermore, a hardware-in-the-loop simulation platform is introduced to verify its effect in slope road condition according to the ON/OFF numbers of solenoid valve in hydraulic system. The simulation results show that the problem of unexpected shift in those working conditions may be resolved by fuzzy modification strategy. At last, it is concluded that although there is some slight decline in power performance in uphill situation, this fuzzy modification strategy could correctly identify slope of road, decrease braking distance, improve vehicle comfort and fuel economy effectively and prolong the life of clutch system. So, this fuzzy logic shifting strategy provides important References for vehicle intelligent shifting schedule.     

Optimization of EBSD parameters for ultra-fast characterization

Ultra-fast pattern acquisition of electron backscatter diffraction and offline indexing could become a dominant technique over online electron backscatter diffraction to investigate the microstructures of a wide range of materials, especially for in situ experiments or very large scans. However, less attention has been paid to optimize the parameters related to ultra-fast electron backscatter diffraction. The present results show that contamination on a clean and unmounted specimen is not a problem even at step sizes as small as 1 nm at a vacuum degree of 6.1 × 10(-5) Pa. There exists an optimum step size at about 50 data acquisition board units. A new and easy method to calculate the effective spatial resolution is proposed. Effective spatial resolution tends to increase slightly as the probe current increases from 10 to 100 nA. The fraction of indexed points decreases slightly as the frame rate increases from 128 patterns per second (pps) to 835 pps by compensating the probe current at the same ratio. The value 96 × 96 is found to be the optimum pattern resolution to obtain optimum speed and image quality. For a fixed position of electron backscatter diffraction detector, the fraction of indexed points as a function of working distance has a maximum value and drops sharply by shortening the working distance and it decreases slowly with increasing the working distance.     

爬壁机器人结构优化设计与吸附力分析

为适应油罐外壁危险作业需要,设计了一款具有有效吸附力和灵活移动能力的新型轮式永磁吸附爬壁机器人。为满足爬壁机器人吸附力平稳并具有负载能力的要求,对爬壁机器人进行静力学分析和动力学建模,得到爬壁机器人在壁面运行的安全吸附力,以保证不发生滑移和倾覆。利用有限元软件分析了磁吸附系统磁铁与壁面间距离、轭铁厚度和磁铁之间距离等结构参数对吸附力的影响规律,并获得最佳结构尺寸。通过实验装置对吸附力进行验证,结果表明实验结果与仿真结果的变化趋势基本一致,为后续的模型制作和改进提供了参考。     

基于指数法评估激光量热仪吸收测量不确定度

为了掌握熔石英样品在紫外波段的吸收特性,研究了精确评估激光量热仪测量不确定度的方法。介绍了激光量热仪的吸收测量原理,选用指数法对吸收测量数据进行了拟合;通过分析各吸收率测量结果的影响分量,建立了测量不确定度评估模型;对各输入量的估计值以及估计值的标准不确定度逐一进行计算,并对影响吸收率测量结果的拟合计算参数A、γ进行了修正。考虑背景温度漂移对被测样品温度测量的影响,利用Matlab编程分析了线性、非线性温度漂移对吸收计算结果的影响,获得其相对标准不确定度及相对扩展不确定度分别为2.6%和5.2%。最后,更换熔石英基底并进行多次吸收测量,计算了吸收率10次测量结果平均值的相对标准不确定度为2.3%,相对扩展不确定度为4.6%,与评估结果基本相同。     

激光跟踪仪多边测量的不确定度评定

激光跟踪仪多边测量是大型高端装备制造现场溯源的重要手段,正确评定其不确定度是确保制造过程量值统一、结果可靠的关键。本文提出了一种准确、快速的激光跟踪仪多边测量的不确定度评定方法。从仪器误差、环境干扰及靶球制造误差等方面分析激光跟踪仪多边测量的不确定度来源。针对多边测量的输出量为多维向量的特点,重点研究基于多维不确定度传播律(GUM法)的不确定度合成方法,同步评定目标点坐标和跟踪仪站位的不确定度。最后,介绍了点到点长度的不确定度计算方法。实验表明:GUM法评定的不确定度结果与蒙特卡洛法(MCM法)的结果相比,坐标不确定度偏差小于0.000 2 mm,相关系数偏差小于0.01,满足数值容差,且GUM法用时仅为MCM法的0.08%;点到点长度测试的En值均小于1。因此,基于GUM法评定激光跟踪仪多边测量的不确定度具有可行性及高效性,且评定结果正确、可靠。     

Simulation and experiment on temperature in micro-detonation of striking arc machining of silicon nitride ceramics

A simulation and machining experiment on temperature during micro-detonation of striking arc machining (MDSAM) of silicon nitride ceramics are performed to reveal the material removal mechanism and study the effect of process parameters on machining performance. A mathematical model is developed for the temperature field of MDSAM, and the temperature and ablation cavity shape of silicon nitride ceramics are studied via simulation method and a machining test. The effects of parameters on temperature field and cavity dimension during MDSAM were computed and analyzed. The results indicated consistency between the simulation and experimental outcomes and showed that machining performance was strongly affected by the process parameters. Bigger working current, pulse width, and small working distance can yield higher temperature and machining efficiency. The nozzle radius should range from 1 to 1.4 mm. This research serves as reference for revealing the machining mechanism and presents a method for the precise control of MDSAM.