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1.
水分测定是冶金行业中矿产原料和产品分析的重要内容,主要包括交货水分、湿存水、化合水等测定类别。尽管水分测定方法本身相对简单,但其涉及到矿物原料、产品结算交割以及其他化学分析的校正计算,属于重要的基础性测定方法。各类矿物、产品几乎都有相应水分测定的国家标准、行业标准,部分还是从国外ISO标准体系中采标而来。文章系统介绍并比较各类矿物原料、产品中交货水分、明水、湿存水、化合水等类别的测定方法。由于ISO标准体系中湿存水含义和国内标准体系湿存水含义有较大差异,其测定操作和用途也有不同,使用空气平衡样品和密封原始样品将会得到数据差异较大的湿存水数据,两种湿存水含义需要明确区分。湿存水对化学称样量、灼减量、化合水的测定有影响,需要用湿存水进行水分校正,才能得到更精确的结果。 相似文献
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性能效率是APP软件的重要质量属性,但目前缺乏APP软件性能效率的通用模型。分析了APP软件的性能特征,基于ISO/IEC 25010标准提出了APP软件的性能效率模型,定义了APP软件性能效率的子特性和度量指标。基于提出的APP软件性能效率模型,通过实验对APP软件的性能效率进行了度量及相关分析。 相似文献
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Statistical testing for sufficient control chart performances during monitoring of grouped processes
Kevin Nikolai Kostyszyn Tobias Claus Brandstätter Thomas Vollmer Robert Schmitt 《Quality and Reliability Engineering International》2021,37(6):2555-2567
With ISO 7870-8, a standardized application of charting techniques for short runs and small mixed batches was presented in 2017. Similar to various scientific approaches, it requires that sample values from grouped processes follow nearly identical distributions. In practice, however, there tend to be differences between distribution parameters. Moreover, equal parameters do not ensure that distributions are properly aligned to the center line and control limits of the chart. These facts can lead to undesired control chart performances which can be expressed by average run lengths (ARL) during in-control and out-of-control conditions. In this work, a statistical test for sufficient control chart performances during monitoring of grouped processes based on preliminary samples is proposed. Control chart performances are defined as sufficient when they deviate within acceptable ranges from usual performances during single process monitoring in mass production. The ARL resulting from estimated distributions and planned production sequences is used as test statistic and calculated via the Markov chain approach. Exemplary tests are executed for scenarios with individuals and cumulated sum (CUSUM) charts. A simulative determination of error rates resulting from the ARL-based testing demonstrates its effectiveness in testing for sufficient control chart performances compared to an indirect testing with Levene's test and a one-way analysis of variance (ANOVA). 相似文献
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Cornelia Wiegand Tanja Hansen Johanna Köhnlein Ines Exner Marlen Damisch-Pohl Peter Schott 《纺织学会志》2018,109(7):891-902
Biocompatibility of six different compression stockings and cytotoxic effects were determined using HaCaT keratinocytes, L929 mouse fibroblasts, primary adult and juvenile keratinocytes Cells were quantified using a luminometric ATP assay and the photometric BCA test. Cytotoxic effects were determined by LDH release. An area-based extraction ratio of 1.25 cm2:mL could be shown to be superior to the weight-based extraction of test material. Extraction medium should be an acidic sweat solution as this helps to recreate in vivo conditions. Monolayer cultures of HaCaT keratinocytes or L929 mouse fibroblasts should be used for testing. Primary adult keratinocytes or primary juvenile keratinocytes can also be used. For the latter, testing under DMEM with FCS is recommended to achieve comparable results. It was found that the compression stockings tested exhibited no negative influence on cell viability in vitro and no direct cytotoxic effects measured as release of LDH. Hence, good biocompatibility could be asserted. 相似文献
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《International Journal of Hydrogen Energy》2020,45(8):5565-5576
Fuel cell electric vehicles and hydrogen refuelling infrastructure are developing quickly in Europe, the USA and Asia. Hydrogen quality for transport applications requires compliance with ISO 14687-2: 2012 and EN 17124:2018 - this needs representative sampling, at the hydrogen production process and at hydrogen dispenser nozzle (which typically fill vehicles to a Nominal Working Pressure of either 35 or 70 MPa). The low thresholds in ISO 14687-2 for oxygen and water can be exceeded if the sampling procedure fails to purge the system sufficiently, which would lead to false results (60% in this study). Purging requirements to remove water were studied using a low pressure sampling rig. For hydrogen dispenser sampling using the Linde H2 Qualitizer (suitable for dispensing pressures up to 70 MPa), purging number and the effect of the initial fill level of a vehicle compressed hydrogen storage system were investigated experimentally to avoid hydrogen quality violation due to oxygen false positive. The study procedure reduces from 60% to 0% hydrogen quality violation. The next challenges highlighted are safe purging and reliable sampling of reactive contaminants in gas cylinders. 相似文献
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白龙煤矿通过实施ISO14001标准,抓基础,促规范,使环境管理更加系统,全面完善了企业环境管理体系,促进了文明生产,提高了企业环境管理水平。对矿井的生产、安全、经营管理起得了一定的促进作用,为企业可持续发展奠定了良好的基础。 相似文献
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介绍了山东省地质测绘院贯彻ISO9000族标准的方法和过程.通过总结该院质量管理体系运行中的经验与体会,进一步认识到,随着社会主义市场经济的日益完善和管理科学的不断发展,产品质量越来越引起各行各业的高度重视,贯彻ISO9000族标准,不仅可以有效地提高企业质量管理水平,而且可以大大地增强企业的市场竞争能力;建立健全质量保证体系,逐步实现管理模式与国际接轨,获取市场准入机会并不断扩大市场占有份额,是企业刻不容缓的重要任务. 相似文献