储存温度对不同包装材料包装的大米品质的影响研究

为了了解温度对不同包装材料包装的大米品质的影响规律,对不同包装材料包装的大米进行了温湿度加速试验,以大米的褐变值、含水量、脂肪酸含量、粘度、霉变为指标,研究了温度对大米品质的影响。结果表明,在相对湿度为90%时,随着储存温度升高和时间的延长,储藏大米的水分含量、粘度、明度值逐渐降低,脂肪酸含量急剧上升,并产生以青霉、黑霉为主的霉菌。     

阿拉尔市枸杞干果的污染菌相调查与防控措施

目的 对阿拉尔市枸杞干果的污染微生物进行调查和分析,以期为新疆枸杞干果的产品质量评价标准提供参考。方法 按照GB 4789—2016《食品卫生微生物学检验标准》中的方法对其进行调查,并进行初步杀菌的应用研究。结果 在供试散装枸杞干果中的污染微生物中,霉菌和酵母菌的菌落总数为8.9×105 CFU/g,细菌的菌落总数为3.5×105 CFU/g,大肠菌群的最可能数（MPN值）为1100;在供试袋装枸杞干果的污染微生物中,霉菌和酵母菌的菌落总数为520 CFU/g,细菌的菌落总数为11000 CFU/g,大肠菌群的MPN值为150,主要污染霉菌为黑曲霉和青霉属。结论 紫外辐照10 min后,霉菌和酵母菌的抑菌率达到32.44%,细菌的抑菌率达到74.69%;超声波处理5 min后,对菌落总数的抑菌效果极为显著,抑菌率达到98.21%。通过紫外辐照和超声波处理均可杀灭枸杞干果表面的微生物,其杀菌效果良好。     

包装材料对大豆贮藏品质影响的研究

目的研究大豆在贮藏过程中包装材料对其品质变化的影响。方法采用3种包装材料(PE,PA/PE,BOPP/PA/PE)对大豆进行真空保鲜包装,监测常规储藏和不同材料包装大豆存储期间品质指标的变化,研究包装材料对大豆保鲜效果的影响。结果用薄膜包装大豆的重要品质指标均明显优于对照组,储藏至18个月时,3种包装大豆的脂肪酸值分别为20.2 mg/100 g,15.5 mg/100 g,13.7mg/100 g,而对照组大豆的脂肪酸值达到28.6 mg/100 g,已开始陈化;3种薄膜包装大豆的蛋白质溶解比率分别为71%,75.8%,74.2%,对照组的大豆蛋白质溶解比率为61.8%,高于国家规定不易存储的临界值。结论包装材料能够明显改善大豆的储藏品质,其中材料的阻隔性对大豆保鲜效果影响最显著,3种薄膜中BOPP/PA/PE的保鲜效果最优。     

稻谷脂肪酸值能力验证试验结果与分析

粮食中的脂肪酸值是反映其贮存品质的重要指标，脂肪酸值增加，说明粮食品质向劣变方向发展。为配合食品市场准入制度的实施，监督和考核通过了计量认证的质检机构的工作，我省计量协会组织了有关质检机构，对稻谷的脂肪酸值进行了一次能力验证试验。对试验未通过的实验室进行了指导和帮助，提高了该试验结果的准确度和可比性。     

不同阻隔性包装材料对月饼品质的影响

一定温湿度条件下,分析不同阻隔性包装材料对月饼品质变化的影响。通过测定袋内月饼的干燥失重、酸价、过氧化值、菌落总数、总糖、脂肪等指标,得出高阻隔性包装材料能够保证存放期间月饼的品质。     

不同阻隔性包装材料对大米储藏品质的影响

本文对高温高湿条件下，不同包装材料对大米品质变化的影响进行分析研究，得出大米品质变化的影响规律。通过测定包装袋内气体成分、水分含量、总酸、脂肪酸、光透差等指标，得出高阻隔性包装材料、特别高阻湿性包装材料能够确保储藏期间大米的品质。     

不同贮藏温度下小黄鱼货架期预测模型的建立和评价

目的探究不同贮藏温度下小黄鱼的品质变化与货架期之间的关系,并建立货架期预测模型。方法设计了273,278,283,288,293 K等5组不同温度下的贮藏实验,对小黄鱼的感官品质指标变化、持水率、pH值、色差(L值、b值)、挥发性盐基氮(TVB-N)、菌落总数和鲜度指标(K值)的变化进行测定分析;运用Arrhenius方程对菌落总数、TVB-N、K值与贮藏时间及贮藏温度建立动力学预测模型。结果菌落总数、TVB-N和K值随着贮藏时间的延长而逐渐增加,感官品质随贮藏时间的延长而下降。结论该模型所获得的货架期预测值准确率达到90%以上,可用于温度为273~293 K范围内小黄鱼剩余货架期的预测。     

包装材料对酱牛肉品质及保鲜期的影响

目的在常温下(15~20℃),为了延长酱牛肉的保鲜期,探讨6种不同的包装材料(PE塑料袋、PE/PP塑料袋、PET/AL/PE复合袋、PP塑料保鲜盒、玻璃保鲜盒和陶瓷保鲜盒)对酱牛肉保鲜期的影响。方法采用不同的包装材料对酱牛肉进行包装,以感官特性、理化性能、微生物为评价指标,比较不同包装材料的差异。结果各组的感官特性均呈下降趋势,采用PET/AL/PE复合袋和玻璃保鲜盒包装的牛肉感官特性值下降稍慢,可保持新鲜4 d;TVB-N值、TBARS值和菌落总数整体呈上升趋势,其中PET/AL/PE复合袋、玻璃保鲜盒以及陶瓷保鲜盒包装的这3个指标上升趋势较慢,可保持新鲜4~5 d。结论保鲜效果优劣顺序为PET/AL/PE复合袋玻璃保鲜盒陶瓷保鲜盒PP保鲜盒PE/PP塑料袋PE塑料袋组不包装组。     

胺基载体选择性渗透膜对西兰花品质的影响

目的研究自制胺基载体选择性渗透膜对西兰花品质的影响。方法以自制选择性渗透膜为包装材料,纯LDPE薄膜处理、硅藻土改性基膜处理、自然放置为对照,于室温密封储存,定期测定各种包装材料内西兰花的品质变化。根据贮存期间各包装材料内西兰花的质量损失率、色差、可溶性固形物含量、硬度、褐变度、维生素C含量等各项指标的变化来评价所制备选择性渗透膜的保鲜性能。结果贮存9 d后,自制选择性渗透膜包装内西兰花的质量损失率、色差、可溶性固形物含量、硬度、褐变度、维生素C含量等指标均高于纯LDPE薄膜、基膜和自然放置对照组,但褐变度低于对照组。结论自制选择性渗透膜能够通过调节包装中CO_2和O_2的选择性渗透,有效控制果蔬呼吸速率,以达到延长储存期的目的。     

包装方式对留胚米品质的影响

目的 研究在3种贮藏温度条件下,4种包装方式对留胚米品质的影响。方法 以实验室自制留胚米（留胚率为85%）为实验材料,选用同一种包装材料,分别采用普通包装、真空包装、充CO2包装和充N2包装等4种方式,并在3种不同温度（5,25,35 ℃）条件下贮藏,以感官品质、含水率和脂肪酸含量为评价指标,定期抽样测量各指标的变化规律。结果 各种包装方式下的留胚米感官品质均随贮藏时间的增加而降低,含水率随贮藏时间的增加呈现先增加后降低的规律,脂肪酸含量随贮藏时间的增加而增加。普通包装的留胚米在5,25,35 ℃下贮藏的保质期分别为45,30,15 d;真空包装的留胚米在5 ℃下贮藏的保质期大于120 d,在25 ℃和35 ℃下贮藏的保质期分别为105 d和90 d;充CO2包装的留胚米在5 ℃和25 ℃下贮藏的保质期为90 d,在35 ℃下贮藏的保质期为60 d;充N2包装的留胚米在5,25,35 ℃下贮藏的保质期分别为90,75,60 d。结论 真空包装为最适宜的包装方式,其次为充CO2包装和充N2包装,普通包装方式的留胚米保质期相对最短。     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

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.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

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.……     

Deposition and Coating Properties on CVD Tungsten

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.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.