三种卷烟端部掉落烟丝测试方法的比较

为了评价ISO/CD 3550-3与ISO 3550-1、ISO 3550-2的稳定性及测试结果的相关性,对15种样品开展了实验研究,利用Bootstrap仿真抽样方法、相关性分析和多因素方差分析对测试结果进行了分析,结果表明:①ISO/CD 3550-3的稳定性与ISO 3550-1和ISO 3550-2在同一水平;②ISO/CD 3550-3和ISO 3550-1及ISO/CD 3550-3和ISO 3550-2的测试结果是显著正线性相关关系;③ISO/CD 3550-3、ISO 3550-1和ISO 3550-2三种测试方法对测试结果有显著影响。      

中美耐摩擦色牢度测试标准比较

从取样、调湿、标准摩擦白布含水率、设备、测试步骤和评级等几个方面比较分析了GB/T3920-1997和AATCC 8-2005两个标准测试内容和方法的异同,并选用20种不同织物按照两个标准分别进行耐摩擦色牢度的测试,比较分析了二者测试结果的差异,以及产生这种差异的影响因素,得出二者内容及测试结果基本相近,只是AATCC 8-2005的测试结果比GB/T 3920-1997所测耐摩擦色牢度要好一些,部分样品能提高半级.     

纺织品中2,4-二氨基甲苯测试结果不稳定性因素分析

本文针对日常检测中按GB/T 17592-2011测试纺织品中2,4-二氨基甲苯含量测试结果出现不稳定的问题,比较GB/T17592-2011和EN 14362-1:2017不同的前处理过程,设计试验方案探究测试结果不稳定的影响因素。试验结果显示:还原裂解液冷却时加入0.2mL质量浓度为10%的氢氧化钠缓冲溶液可提高测试结果稳定性,而萃取溶剂、洗脱方式的选择以及样品本身的p H值对测试结果无显著影响。     

纺织品耐光、汗复合色牢度各测试标准对比

本文对比了GB/T 14576-2009、ISO 105-B07：2009、AATCC 125-2009、JIS L 0888：2005测试标准的测试原理、试验设备和条件、操作程序及结果判定等。     

最新国际纺织品耐汗渍色牢度测试方法与国标方法测试的结果差异比较

耐汗渍色牢度是纺织品色牢度测试中的主要测试项目之一,它也是中国纺织品强制性国家标准GB 18401-2010规定的考核指标之一。本文通过比较GB/T 3922-1995、ISO 105 E04-2013和AATCC15-2013三个耐汗渍色牢度测试标准的异同,分析测试结果的差异性,同时提出一些日常测试中的质量控制建议。     

羊毛纤维密度的液体浮力法测试

采用液体浮力法对原毛、氯化防缩羊毛和拉伸细化羊毛3种纤维密度进行了测试研究．分析了不同测试介质、不同脱泡工艺和不同纤维结构对纤维密度测试值的影响。实验结果表明：脱泡工艺是测试精度的关键,采用高速离心-煮沸-抽真空进行脱泡,操作简便易行,测试数据稳定、准确;无水乙醇为介质的测试精度要好于蒸馏水;羊毛拉伸细化工艺较常规化学处理更易造成纤维结构的不匀,给密度测试带来一定误差。     

纺织品耐人造光色牢度测试方法

纺织品采用GB/T 8427-2008<纺织品色牢度试验耐人造光色牢度:氙弧>测试标准测试耐光色牢度时,由于采用的测试仪器参数不同,以及测试条件的差异,导致实验室间的测试参数存在较大差异.针对这些问题,对GB/T 8427-2008测试标准中各测试条件(辐照强度、样品架温度、舱体温度、舱内温度和曝晒时间)进行了试验分析,优化了部分试验参数,为准确理解标准提供参考.     

织物勾丝性能测试方法的比较

从适用范围和原理、仪器设备、操作步骤和评级等方面分别进行阐述了中国、美国和日本织物勾丝性能的测试标准GB／T11047—1989、ASTM D 3929-2003和JISL 1058-2005，分析了其异同点。三种标准方法由于规定的勾丝转数不同，测试结果差异很大。若勾丝测试结果较好，则差异仅为0．5级；若勾丝测试结果较差，则差异可高达2．5级。     

水中碱度测定的探讨

水中碱度的测定对工业废水、工业用水以及在生活污水的处理运转和科研中有着非常重要的意义。通常,水中的碱度测试一般会运用多种指示剂对水中的含碱量进行对比测试。经过研究,选择茜素红-甲基红与酚酞混合的指示剂具有良好的测试效果;采用甲基橙与酚酞有比较好的测试结果;而采用溴甲酚绿-甲基红与百里酚蓝-甲酚红混合的指示剂的测试效果不是很理想。经过对比结果采取百里酚蓝和甲酚红混合的指示剂作为水中碱度测定的最优指示剂。     

浅谈测试金属钠用盐中SO42-的方法

本文根据金属钠用盐的理化指标要求及测试现状 ,通过对大量测试试验的总结 ,探索出测试SO42 -准确、快速、重复性好的方法及其测试条件 ,适用于金属钠用盐的生产控制分析和产品分析。     

液压式矿用钢丝绳弯曲疲劳试验机的研究

根据GB/T 12347—2008和GB/T 12347—1996规定,矿用钢丝绳进行弯曲疲劳试验需配置多台试验机或多个试验轮,硬件装备及实验室建筑占地多、费用高,试验过程钢丝绳受到的冲击力较大,试验结果难以同矿用钢丝绳在较平稳运动状态下运行的实际情况相吻合。按照GB/T 12347—1996的试验原理新研制的矿用钢丝绳弯曲疲劳试验机采用液压马达驱动,直接实现180°平面反复弯曲运转,具有通用性较强、频率范围宽、结构简单、自动化程度较高等特点。钢丝绳的连接采用去绳芯加钢棒焊接对接。     

纺织品透气性测试

常用纺织品透气性的测试标准有ASTM D737--1996和GB/T 5453--1997,分析对比其测试条件和测试结果,考察了织物材料、组织结构、加工方式和水洗次数等因素对织物透气性的影响.结果表明,用ASTM D737--1996与GB/T 5453--1997的测试结果呈现较高的相关性;棉、麻、羊毛等天然纤维和蛋白质纤维织物的透气性好于尼龙、涤纶等合成纤维织物;织物透气性的顺序为:透孔织物>缎纹织物>斜纹织物>平纹织物;前5次水洗后,织物的透气率变化明显,而后逐渐趋于平缓;液氨整理能提高织物的透气性,三防整理会明显降低织物的透气性;焙烘后织物的透气性均比焙烘前有所增加.     

Effects of context and repeated exposure on food liking: The case of boar taint

This study investigated whether consumer acceptance of boar meat is overestimated by standardised situational testing and whether repeated exposure decreases liking. Thus, a home use test (HUT) followed by a central location test (CLT) was conducted to assess the acceptance of minced boar meat with approximately 14% fat either HIGH or LOW in androstenone (2.0 vs. 0.30 ppm) and skatole (0.30 vs. 0.06 ppm) in comparison to meat from castrates and gilts (CONTROL). In HUT, no significant difference (p > .05) in dislike frequency was observed between CONTROL and LOW. For HIGH, liking was strongly impaired during frying. The results indicated a masking effect of the ready-made sauce on the odour but not on the flavour. In CLT, dissatisfaction was generally higher than in HUT. Similar to HUT, HIGH boar meat was more often disliked (p < .001) compared to LOW and CONTROL in the CLT. To conclude, standardised testing did not underestimate acceptance. In contrast to anticipations, a single previous exposure to boar meat with high levels of androstenone and skatole did not affect (p > .05) liking in the follow-up CLT.     

纺织品耐氯化水色牢度试验方法的研究

本文对GB/T8433—1998、AATCC162—2002、JISL0884—1996三个标准的耐氯化水色牢度测试方法进行了比较研究,得出有效氯浓度影响色牢度等级的规律性。     

Testing meat tenderness using an in situ straining stage with variable pressure scanning electron microscopy

This project developed analytical protocols allowing in situ tensile testing of beef M.semitendinosus in a variable pressure scanning electron microscope (VP-SEM) fitted with a straining stage. The objective of this project was to develop an appropriate testing regime for the tensile testing of meat following various pre-treatments (marinaded, cooked, frozen). The in situ testing, at 100% relative humidity, was validated with ex situ testing using the same tensile stage. From the ex situ tensile tests the apparent elastic modulus ranged from 0.1 MPa to 0.3 MPa with the cooked, non-marinaded meats being stiffest. The low strain rates imposed by mechanical considerations of the straining stage resulted in lower values of fracture toughness and UTS than those reported in the literature. Fracture behaviour observed during the in situ tensile tests revealed that fracture propagated across the perimysial connective tissue. For the cooked non-marinaded steak, catastrophic rupture occurred in the crosslinks of the connective tissue. The cooked marinaded steak with more gelatinized connective tissue showed a less catastrophic rupture. Limitations of the testing geometry of an in situ straining stage are critical for their impact on image quality. The working distance for VP-SEM is necessarily short meaning that a sample needs to be close to the final lens of the SEM for high quality images. This is hard to achieve within the geometrical constraints of most sample chambers. However, it was possible to capture real time images of muscle failure during tensile testing of meat and relate that to the impact of meat processing treatments. Such information is vital for determining the structural factors affecting meat tenderness.     

Similarity testing using paired comparison method

Statistical model and procedure for similarity tests using paired comparison method are developed in the framework of the “two one-sided tests” (TOST) according to the intersection-union test (IUT) principle. Critical values, testing powers and sample sizes for the tests are provided based on the binomial distribution. Confidence intervals used in similarity testing are discussed. Current practice of using the conventional confidence intervals in two-sided similarity testing is criticized. A 100(1 − α)% confidence interval associated exactly with a α-level TOST is provided. Two key points are addressed in the paper. (1) Unlike difference testing, no multiplicity adjustment is needed to achieve an overall α-level in the two-sided similarity hypothesis tests. (2) The conventional two-sided confidence intervals do not match the TOST.     

金属材料维氏硬度测量不确定度的评定

维氏硬度测量的不确定度主要来源于试验力、压痕对角线重复性、标准块不均匀性及硬度计本身;建立维氏硬度与试验力、压痕深度的数学模型,指出维氏硬度与试验力成正比,与压痕深度的平方成反比;根据GB/T4340.1—1999,从试验力、压痕、标准块等几个影响因素分析,计算出当包含因子Kp=2,置信区间为95%时,维氏硬度测量的不确定度为2.5%。     

DNA extraction and fingerprinting of commercial rice cereal products

DNA was extracted from commercial rice cereal products using modified conventional methods (CTAB, SDS and a commercial kit) in large fragments (>3 kb) and with relatively high yields (1.4–10.7 μg DNA per g of sample) and was used as template for the amplification of a single copy rice gene (i.e. MIPS) fragment (ca. 850 bp) and microsatellite DNAs (ca. 120–400 bp). The cereal products were further discriminated by using six microsatellite markers. The usefulness of DNA analysis was discussed for quality control and authenticity testing of raw rice materials in rice-based food production, and to monitor genetically modified (GM) rice ingredients in commercial food products.     

Gelation properties of salt soluble meat protein and soluble wheat protein mixtures

Salt soluble meat proteins (SSMP) and commercially available soluble wheat proteins (SWP) were characterised by SDS-polyacrylamide gel electrophoresis, differential scanning calorimetry (DSC) and small and large deformation testing. DSC scans indicated transitions similar to those of native actomyosin for the salt soluble meat extract whereas SWP did not indicate any transitions between 20 and 120 °C. Small deformation tests on SWP indicated a G′/G″ crossover gelation temperature of 90 °C and weak gels as judged by frequency sweeps. In contrast, SSMP gelled at 40 °C and formed strong gels on heating to 90 °C. However, on autoclaving at 120 °C, 20% SWP in distilled water produced strong elastic gels with little syneresis, compared with the more brittle gels produced with 20% (w/w) SSMP as indicated by large deformation testing. Mixtures of the two proteins in the ratio SSMP/SWP (15:5) gave strong elastic gels similar to the SWP gels. Even the presence of very small amounts of SWP in the mixture, e.g. SSMP/SWP 20:1 trebled the elastic modulus compared with a SSMP gel and reduced syneresis. This was probably due to the close association of SWP with actomyosin strands as viewed by transmission electron microscopy. However, increased levels of SWP in the mixture, for example SSMP/SWP 10:10 ratio, resulted in the separation of the two protein phases as shown by phase contrast microscopy, and consequently led to lower G′ values in the mixed gels. The addition of 20 mM chloride salts showed that potassium reduced the shear modulus, sodium had no effect and calcium enhanced the shear modulus for SWP gels formed at 120 °C. In contrast, SSMP gels were stronger in the presence of potassium, followed by sodium and calcium.     

Effects of two transport systems on lamb welfare and meat quality

The aim of this study was to analyse the effect of a direct transport system (DTS) versus transport with a logistic stopover system (TLS) on lamb welfare and meat quality at two seasons. A total of 96 lambs were sampled in a 2 × 2 × 2 factorial design, testing two transport systems and two seasons (summer and winter), with two replicates in each season. Significant interactions (P ≤ 0.05) between transport system and season in both welfare and meat quality were found. In general, lambs subjected to direct transport and logistic stopover during winter had a more intense stress response and poorer meat quality than lambs transported during summer. However, direct transport during the cold season seemed to be the most stressful, compared to the rest of the groups, which was reflected in significantly higher levels of cortisol, lactate, glucose, ratio of N/L, higher pH24 and darker and tougher meat.