备样方法对标准吸湿含水率的影响

利用室内试验手段研究了不同备样方法对标准吸湿含水率的影响。研究结果表明:原状样和调制样的试验结果大于风干样和烘干样;原状样与其他3种备样方法的试验结果呈线性关系,相关系数的平方为0.94～0.97,说明在原状样缺乏时可采用其他备样方法的试验结果来代替,但必须对其进行修正。

Anton Paar啤酒全自动分析仪备样方法的探讨

本文讨论了Anton Paar啤酒全自动分析仪测定啤酒原麦汁浓度时样品除气备样的几种方法。根据仪器提供的除气方法，确定出超声波，磁力搅拌和抽真空三种除气方法的条件，对所测得的结果进行了比较。超声波，磁力搅拌和抽真空三种方法都可以较好地避免人为因素的误差，是值得推荐的除气备样方法。

瓦楞纸板自动备样装置设计及应用

目的 提高瓦楞纸板取样器的精度和效率。方法 结合相关国家标准的规定,设计了一种瓦楞纸板自动备样装置。装置主要由箱体、工作台、进样盘、进样盘横向限位条、旋转刀片、电机轴、切样垫板、瓦楞纸板纵向限位件、触摸屏控制系统和安全防护罩等部件组成。结果 切出的样本合格率高,楞孔清晰,无毛边及撕边现象,楞边平行度高;工作效率高,切出合格样品的速度达1500～1800个/小时;安全防护罩即开即停,安全性高;旋转切削方式使得刀片耐用,节省成本。结论 该装置取样精度和效率高,具有很强的实用性。

监督抽查中“三同”及备样复查的问题

求。否则,即便监督抽查程序准确无误,也无法保证监督抽查结果的正确,甚至会产生不为人知的错误。这一点产品质量监管部门应有清晰的认识。

基于玻璃啤酒瓶抗冲击检验结果重复性的对策研究

目的通过对啤酒瓶的抗冲击项目进行重复性测试,分析质量水平与公布数据之间的差异原因,探求适合持续监管和减少异议复检的对策。方法通过在同等条件下,对99组不同地区、不同厂家、不同规格的样品进行连续检测抗冲击指标,统计该项目结果的再现性。结果抗冲击项目在相同条件下的连续检测,不论是通过组还是未通过组,其结果再现性都很低。同理,监督工作中如运用备样进行复检,并以复检结果作为最终定论,可造成大概率的结论否定,给监管工作增加难度,使承检机构出具报告处于两难境遇。结论啤酒瓶抗冲击指标作为重复性很低的破坏性试验项目,不适合在监督工作中的备样复检,应严格规范试验过程,保留现场试验影像记录等方式,作为异议复检的证明资料对策运用,不但要能便于持续性监管,避免自我否定,而且还能维护各方的权益,确保监督工作的公信度。

解读《产品质量监督抽查管理暂行办法》规定

《产品质量监督抽查管理暂行办法》是指导产品质量监管部门开展监督抽查的准则,应该准确理解与把握。但是,一些监管部门或人员在执行与应用中,对其规定的含义与指向存在认识偏差,容易造成监督抽查的错判。文中根据产品质量监督抽查控制理论,结合监督抽查的本质与目的进行分析与解释,指出如何正确地理解与应用《产品质量监督抽查管理暂行办法》的规定,并提出建议。

家用电器产品随机抽样方法简介和实操应用

本文详细介绍了随机抽样的四种方法和家用电器产品质量监督抽查抽样时四种随机方法的应用。在生产企业对家用电器成品不同包装和摆放的情况下,作者根据GB/T 2828系列抽样标准中的术语和定义具体分析为何需要选取不同随机抽样方式的原因和阐释了随机抽样方法的组合应用的方式。

Application of EBSD technique to ultrafine grained and nanostructured materials processed by severe plastic deformation:Sample preparation, parameters optimization and analysis

With the help of FESEM, high resolution electron backscatter diffraction can investigate the grains/subgrains as small as a few tens of nanometers with a good angular resolution （~0.5°）. Fast development of EBSD speed （up to 1100 patterns per second） contributes that the number of published articles related to EBSD has been increasing sharply year by year. This paper reviews the sample preparation, parameters optimization and analysis of EBSD technique, emphasizing on the investigation of ultrafine grained and nanostructured materials processed by severe plastic deformation （SPD）. Detailed and practical parameters of the electropolishing, silica polishing and ion milling have been summarized. It is shown that ion milling is a real universal and promising polishing method for EBSD preparation of almost all materials. There exists a maximum value of indexed points as a function of step size. The optimum step size depends on the magnification and the board resolution/electronic step size. Grains/subgrains and texture, and grain boundary structure are readily obtained by EBSD. Strain and stored energy may be analyzed by EBSD.

样品管理的作用

保留样品是在制取供检验用样品的同时获得的备份样品,它具有供检验用样品同等的物料特性。它不仅是检验,而且是维护检测机构自身利益的需要,应引起我们的充分关注。

《产品质量监督抽查管理暂行办法》实施中的一些思考

为更好地规范生产流通领域产品质量监督抽查工作,适应市场发展的需要,现从“被抽样生产者”“同一产品”“备样”三方面对《产品质量监督抽查管理暂行办法》(国家市场监督管理总局第18号令)实施过程中存在的一些问题进行了深入剖析,并提出了改进的建议。

Improved oxidation resistance of chemical vapor reaction SiC coating modified with silica for carbon/carbon composites

To protect carbon/carbon (C/C) composites from oxidation, a SiC coating modified with SiO2 was prepared by a complex technology. The inner SiC coating with thickness varying from 150 to 300 μm was initially coated by chemical vapor reaction (CVR): a simple and cheap technique to prepare the SiC coating via siliconizing the substrate that was exposed to the mixed vapor (Si and SiO2) at high temperatures (1 923?2 273 K). Then the as-prepared coating was processed by a dipping and drying procedure with tetraethoxysilane as source materials to form SiO2 to fill the cracks and holes. Oxidation tests show that, after oxidation in air at 1 623 K for 10 h and thermal cycling between 1 623 K and room temperature 5 times, the mass loss of the CVR coated sample is up to 18.21%, while the sample coated with modified coating is only 5.96%, exhibiting an obvious improvement of oxidation and thermal shock resistance of the coating. The mass loss of the modified sample is mainly contributed to the reaction of C/C substrate with oxygen diffusing through the penetrating cracks formed in thermal shock tests.

Effect of aging treatment on irradiation-induced segregation of high Mn-Cr steel

To investigate the effect of aging treatment on irradiation-induced segregation of high Mn-Cr steel, specimens for electron-beam irradiation were prepared from the high Mn-Cr austenitic steel which was solution treated at 1 373 K for 1 h and aging treated at 573 K for 1 000 h, respectively. The electron-beam irradiation was performed at 573 K up to doses of 5.4 dpa in a 1 250 kV HVEM and irradiation-induced segregation analyses were carried out by an EDX in a 200 kV FE-TEM. The results show that void formation is not observed in both solution treated and aging treated ones. The amount of Cr segregation at the grain boundary decreases in the aged one; however, that of Mn is not changed in solution treated one.

Differential diagnosis in patients with suspected bile acid synthesis defects

AIM: To investigate the clinical presentations associated with bile acid synthesis defects and to describe identification of individual disorders and diagnostic pitfalls. METHODS: We describe semiquantitative determination of 16 urinary bile acid metabolites by electrospray ionization-tandem mass spectrometry. Sample preparation was performed by solid-phase extraction. The total analysis time was 2 min per sample. We determined bile acid metabolites in 363 patients with suspected defects in bile acid metabolism. RESULTS: Abnormal bile acid metabolites were found in 36 patients. Two patients had bile acid synthesis defects but presented with atypical presentations. In 2 other patients who were later shown to be affected by biliary atresia and cystic fibrosis the profile of bile acid metabolites was initially suggestive of a bile acid synthesis defect. Three adult patients suffered from cerebrotendinous xanthomatosis. Nineteen patients had peroxisomal disorders, and 10 patients had cholestatic hepatopathy of other cause. CONCLUSION: Screening for urinary cholanoids should be done in every infant with cholestatic hepatopathy as well as in children with progressive neurological disease to provide specific therapy.

Preparation and Characterization of γ-Al2O3 by Polyaluminum Chloride with High Al13 Content

In this paper a polyaluminum chloride solution with high Al13 content was prepared and used as raw material for preparation ofγ-Al2O3.The texture and crystalline phase of the prepared alumina samples were characterized by energy dispersive X-ray spectroscopy(EDX) ,X-ray diffraction,transmission electron microscope(TEM) and nuclear magnetic resonance(NMR) analyses.The effects of alkaline solution and calcination temperature were investigated.The results showed that alkaline solution including NH3·H2O and NaOH had little effect on the alumina sample formation.The impurities of NH4Cl and NaCl in solution can be removed through repeated washing by EDX analysis.Calcination temperature had a significant effect on alumina crystal phase.The alumina sample can transform completely toγ-Al2O3 in the subsequent heating from 600°C to 800°C.It is very interesting that Al13 can be existed inγ-Al2O3 phase even after calcinations.The results indicate that polyaluminum chloride with high Al13 content is an effective material to prepareγ-Al2O3.

Behavior of phenol adsorption on thermal modified activated carbon

Adsorption process is acknowledged as an effective option for phenolic wastewater treatment. In this work, the activated carbon （AC） samples after thermal modification were prepared by using muffle furnace. The phenol ad- sorption kinetics and equilibrium measurements were carried out under static conditions at temperature ranging from 25 to 55 ~C. The test results show that the thermal modification can enhance phenol adsorption on AC samples. The porous structure and surface chemistry analyses indicate that the decay in pore morphology and decrease of total oxygen-containing functional groups are found for the thermal modified AC samples. Thus, it can be further inferred that the decrease of total oxygen-containing functional groups on the modified AC sam- ples is the main reason for the enhanced phenol adsorption capacity. For both the raw sample and the optimum modified AC sample at 900 ~C, the pseudo-second order kinetics and Langmuir models are found to fit the exper- imental data very well. The maximum phenol adsorption capacity of the optimum modified AC sample can reach 144,93 mg.g ~ which is higher than that of the raw sample, i.e. 119.53 mg.g 1. Adsorption thermodynamics analysis confirms that the phenol adsorption on the optimum modified AC sample is an exothermic process and mainly via physical adsorption.

Sample Preparation of Urine Samples Prior to CE-MS in Toxicological Analysis

Capillary electrophoresis （CE） coupled with mass spectrometry （MS） with a sheath liquid interface is nowadays recognized as a powerful separation technique for drugs and metabolites analysis in human urine and can be applied in numerous fields such as clinical toxicology, drug substitution monitoring, forensic sciences and antidoping. With an acidic background electrolyte containing 15 mM ammonium formate at pH 2.5 and a sheath liquid consisting in a mixture of isopropanol/water （50：50, v/v） with 0.5% formic acid, CE-ESI-MS in positive mode demonstrated excellent performance for simultaneous analysis of basic drugs of abuse and metabolites in urine （e.g. cocaine, amphetamine, morphine and phase II metabolites）. To achieve the desired level of sensitivity, two injection modes and three sample pre-treatments were evaluated. The detection of basic drugs and phase Ⅱ metabolites in diluted urine was achieved at concentrations above 1μg/mL. In order to enhance sensitivity, a sample preparation was required. A liquid-liquid extraction （LLE） was compared with solid-phase extraction. LLE was performed at alkaline pH and samples were electrokinetically injected. A chemometric approach （Doehlert design） was carried out in order to determine optimized injection parameters. Limits of detection （LOD） down to 10 ng/mL were reached with field-amplified sample injection but phase II metabolites were not extracted. Therefore, instead of LLE a SPE was performed on C 18 sorbent, and elution fraction after washing step containing phase Ⅱ metabolites was loaded on mixed-mode anion exchanger cartridges. After electrokinetic injection, this two-step SPE allowed LOD ca. 10 ng/mL for drugs and phase Ⅱ metabolites.

Anion Content in Surface and Subsurface Water Flows in Grassland

Grassland devoted about 90% of agricultural Irish land. Anion retention capacity of most agriculture soils is less than cation retention capacity, therefore chemical analyzed for anion （NO3 （nitrate）, CI- （chloride）, SO42 （sulphate） and HPO4 （biphosphate）） in different water flow types （overland flow, interflow and vertical flow or drainage） samples. In this work, simple equipment was used to operationally distinguish between overland flow and interflow while vertical flow collected in different depths using soil water sampler equipments. Episodes of overland flow and interflow occurred even though the site is located in the lowest rainfall in Ireland and on well-drained soil. Samples of different origin showed marked differences in their anion contents, while HPO4 concentrations were almost equal to zero in all water flow types, nitrate where relatively high in overland and interflow samples and was very high in drainage samples. No sampling was carried out below the root zone but it must be assumed that the high concentrations measured in drainage samples would constitute a threat to groundwater resources. When overland flow and interflow did occur, NO3 concentrations were usually close to or in excess of the maximum admissible concentrations for drinking water and it will be constituted a threat to inland surface water bodies.

Effects of coal rank, Fe_3O_4 amounts and activation temperature on the preparation and characteristics of magnetic activated carbon

Coal-based Magnetic Activated Carbons （CMAC＇s） were prepared from three representative coal samples of various ranks： Baorigele lignite from Inner Mongolia; Datong bitumite from Shanxi province; and Taixi anthracite from Ningxia Hui Auto- nomous Region. Fe3O4 was used as a magnetic additive. A nitrogen-adsorption analyzer was used to determine the specific surface area and pore structure of the resulting activated carbons. The adsorption capacity was assessed by the adsorption of iodine and methylene blue. X-ray diffraction was used to measure the evolution behavior of Fe304 during the preparation process. Magnetic properties were characterized with a vibrating-sample magnetometer. The effect of the activation temperature on the performance of CMAC＇s was also studied. The results show that, compared to Baorigele lignite and Taixi anthracite, the Datong bitumite is more appropriate for the preparation of CMAC＇s with a high specific surface area, an advanced pore structure and suitable magnetic properties. Fe304 can effectively enhance the magnetic properties and control the pore structure by increasing the ratio of meso- pores. An addition of 6.0% Fe304 and an activation temperature of 880 ℃ produced a CMAC having a specific surface area, an iodine adsorption, a methylene blue adsorption and a specific saturation magnetization of 1152.0 m2/g, 1216.7 mg/g, 229.5 mg/g and 4.623 emu/g, respectively. The coal used to prepare this specimen was Datong bitumite.

Production and Quality Evaluation of Pringles from Composite Flour of Cocoyam and Wheat Flour

Work assessed ＂Pringles＂ as an imitate snack produced from composite flour of cocoyam and wheat. This was carried out in order to exploit the nutritional and aesthetic value of cocoyam （Colocasia escullenta Vat.） to improve the overall quality of the Pringles as against its production from potato and wheat composite flour. Composite flour （100%：0%, 90%：10%, 80%：20%, 70%：30%, 60%：40% and 50%：50%） of cocoyam and wheat respectively as the major raw materials were adopted and used for the production of the Pringles. Physicochemical analysis （pH, water absorption capacity （WAC）, bulk density （BD） and swelling capacity （SC））; proximate analysis （protein, fats, ash, moisture and carbohydrate content） and sensory evaluation （colour, texture, taste and overall acceptability） were carried out on the samples produced using standard methods. Physicochemical analysis showed the pH of 5.48 to 6.61, WAC （12.00 to 17.50）, BD （1.43 to 1.56） and SW （1.03 to 1.38）. However, sample with 10% cocoyam and 90% wheat composite flour gave the best physicochemical properties of pH （5.98）, WAC （14.00）, BD （1.56） and SC （1.38）. The proximate analysis showed that carbohydrate content ranging between 53.36 to 61.12, and protein content （8.17 to 12.29）, fat content （16.67 to 23.97）, ash content （3.49 to 45.53）, fiber content （1.71 to 2.83） and moisture content （8.76 to 14.54）. Sample B equally gave the nutrient proximate combination of appreciable percentage on the average. The result of the sensory evaluation showed that there is no significant difference between the samples produced in terms of aroma. There is a significant different between samples A, B and the remaining samples in terms of colour and taste. On the overall acceptability, samples A, C and D showed no significant difference but the highest mean score was found with sample B. Conclusively, acceptable snack （Pringles） can be produced from cocoyam and wheat in ratio 90%： 10%, respectively.

Effect of Radiant Energy Vacuum on Physical and Microbial Properties of Beef Jerky

To test the feasibility of radiant energy vacuum （REV） dehydration, a technology that couples microwave cooking with vacuum pressure, on beef jerky preparation, the physical and microbial properties of the final jerky product was compared to conventional preparation methods. Physical characteristics assessed using puncture and shear tests of samples prepared using REV dehydration compared to the traditional method were not statistically different （P 〈 0.05）. Moisture content and water activity levels were also very similar between the two products, To test microbiological quality, samples were homogenized in a stomacher and a variety of 3 M Petrifilms were used to evaluate the microbial load. Raw beef harboured low numbers of microbes, but the post-marination pasteurization/smoking step used in both treatments eliminated all culturable microorganisms tested for. To further investigate the ability of REV dehydration to kill microbes, samples were spiked with Listeria innocua after the pasteurization/smoking step but prior to REV dehydration. Samples were taken at different time intervals for microbial enumeration, and a decimal reduction time of 1 min was calculated, with 99.99% of 1.98 × 10^7 CFU g^-1 Listeria being killed in five min. Improved drying times were observed for jerky samples prepared using the REV method offering potential energy savings during jerky preparation.