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151.
152.
圆管无芯弯曲壁厚变薄量研究 总被引:1,自引:0,他引:1
耿相军 《锻压装备与制造技术》2006,41(3):86-88
采用回归分析和曲线拟合方法,提出圆管无芯弯曲壁厚减薄量新的计算公式。经验证该公式比目前实际采用的变薄量计算公式具有更高的计算精度。 相似文献
153.
154.
本文将水处理使用的表面活性加入在不同的陶瓷原料(安塘泥、镁质泥、膨润土)中,并与传统减水剂进行对比,研究其解胶效果。结果表明,表面活性剂对安塘泥的解胶效果不明显,pc-67和三聚磷酸钠对安塘泥有较好的解胶效果。TH904对镁质泥有较好的解胶效果,其效果接近pc-67.表面活性剂对膨润土均有不同程度的解胶效果,但是单独作用的效果不显著。 相似文献
155.
156.
采用无压烧结,以AlN与Y2O3的摩尔分数为60%∶40%作为烧结助剂进行碳化硅液相烧结,得到致密的烧结体。研究不同添加剂含量和不同保护气氛对烧结工艺的影响,并对烧结体的显微形貌和相进行分析。结果表明,高烧结助剂含量可在较低温度下实现致密化,但高温下液相挥发导致密度降低。与氩气作为保护气氛相比,氮气可抑制氮化铝的分解反应,有利于烧结。烧结体的晶粒均匀、细小,第二相均匀分布。烧结体的主相为6HSiC,并有氧氮化物的生成。 相似文献
157.
Free-radical scavenging capacity and reducing power of wild edible mushrooms from northeast Portugal: Individual cap and stipe activity 总被引:6,自引:0,他引:6
Isabel C.F.R. Ferreira Paula Baptista Miguel Vilas-Boas Lillian Barros 《Food chemistry》2007,100(4):1511-1516
The antioxidant properties of two wild edible mushroom species from the northeast of Portugal, Lactarius deliciosus (L.) Gray and Tricholoma portentosum (Fr.) Quél., were evaluated. Methanolic extracts from the entire mushroom, the cap and the stipe, separately, were screened for their reducing power and free radical scavenging capacity by chemical assays. The total phenolic content was determined, in order to assess its effect on the extract’s antioxidant activity. Both two species showed antioxidant potential; but L. deliciosus proved to be more active. The portion of the mushroom used had an influence on the results obtained, with the cap methanolic extracts exhibiting the greatest antioxidant effect. 相似文献
158.
本文介绍了一款自主开发的新型盒式气调包装机,并对关键零部件的结构和功能进行了详细的说明和深入的解析。所述包装机克服了以往采用冲洗式气体置换方式导致置换精度不高的缺陷,同时运用新的传送方式来实现产品的连续化生产。 相似文献
159.
ABSTRACT: Swordfish fillets, dry-salted and treated with liquid smoke, were sliced and packed in vacuum conditions and under modified atmosphere (MA) (5% O2 ,45% CO2 , 50% N2 ) and stored at chilled temperature (4°C) to determine the effect of different packaging on shelf-life. Sensory attributes, total volatile basic nitrogen (TVB-N), pH, lipid oxidation by thiobarbituric acid test, and microbiological counts were monitored during 45 d of storage. The TVB-N increased to levels recommended by European regulation at the time of sensory rejection, resulting as the most reliable parameter of quality decay. Lipid oxidation was low and microbial counts could not be correlated with quality decay. Sensory rejection (at least 50% of the assessors scoring =5 in a scale from 1 to 9) was sooner for MA-packed samples (12d) than for vacuum-packed ones (42d). 相似文献
160.
Siyuan Zhou Shiowshuh Sheen Yu‐Hsin Pang LinShu Liu Kit L. Yam 《Journal of food science》2013,78(5):M725-M730
Salmonella contamination on raw shrimp is a big food safety concern in the United States currently. This research evaluated the inhibition effects of vapor phase thymol, modified atmosphere (MA), and their combination against Salmonella spp. on raw shrimp. Growth profiles of a Salmonella spp. cocktail (6 strains), inoculated onto the surface of raw shrimp, treated with vapor phase thymol at 3 levels (0, 0.8, and 1.6 mg/L), or MA (59.5% CO2 + 39.5% N2 + 1% O2), both alone and in combination, at 3 temperatures (8, 12, and 16 ºC), were determined. Lag time and maximum growth rate of Salmonella spp. under each treatment were obtained using Baranyi and Roberts models. Results indicated that both vapor phase thymol and MA treatments alone inhibited the growth potential of Salmonella spp. effectively, extending the lag time by 10% to 100% and reducing the maximum growth rate by 14% to 71% compared with controlled samples at experimental temperatures (8, 12, and 16 ºC). Combination treatments of vapor phase thymol and MA exhibited greater inhibition effectiveness than each individual treatment and a synergistic antimicrobial effectiveness could be observed on the lag time extension. To the maximum, at 12 ºC, lag time of Salmonella spp. was extended 59.6% more by the combination treatment of 0.8 mg/L thymol + MA (36.97 h) than those effects combined from 0.8 mg/L thymol treatment and MA treatment alone (23.16 h in total). This combination strategy could be potentially utilized for Salmonella inhibition during the long distance and temperature‐abused raw shrimp import process. Practical Application The vapor phase thymol + MA combination strategy could be potentially applied in temperature‐abused and long‐distance raw shrimp import process to retard the Salmonella spp. growth, therefore reducing its import rejection rate as well as enhancing its food safety level to the consumers’ concerns. 相似文献