压铸模具设计制作易被忽视的细节

列举压铸模具在设计和制作时易忽视的细节,这类细节往往会导致模具制作进程缓慢,甚至要通过多次修理与试模才能合格,同时提出了重视这些细节的具体措施,以达到提高模具寿命、缩短制作周期、提高模具和铸件品质的目的。     

机器人模具抛光系统中抛光工具位姿研究

为了弥补抛光机器人通过示教方式采集抛光点的不足,充分利用了模具数控加工在路径规划方面的功能,生成模具加工表面刀位点,编写算法提取在UG NX 7.5的CAM模块上生成的模具加工数控刀位数据,并在这些数据的基础之上,设计了工业机器人抛光工具的位姿算法。     

MP3前盖注塑模具浇口的优化设计

介绍了Mold flow软件在MP3外壳注塑模具浇口位置设计中的应用,从产品的填充时间和熔接痕等方面,对不同的浇口设计方案进行了对比,最终确定了最佳的浇口位置。     

汾酒大曲上霉四法

上霉的多少决定汾酒大曲成曲时间的长短,直接影响汾酒的口感香型。     

壳聚糖及其季铵盐与离子液体复配用于皮革防霉性能研究

选用皮革常见的黑曲霉和青霉作为试验菌种,将壳聚糖及2-羟丙基三甲基氯化铵壳聚糖（壳聚糖CTA季铵盐）用于皮革防霉研究。结果表明：壳聚糖及壳聚糖CTA季铵盐对青霉和黑曲霉有一定的防霉效果,其中壳聚糖CTA季铵盐稍好,但都不理想。将它们分别与离子液体1-丁基-3-甲基咪唑三氟甲磺酸盐复配后,防霉效果显著提高,当壳聚糖及壳聚糖CTA季铵盐浓度为0.0025g/L时仍表现很好的抑菌效果。这说明离子液体有利于壳聚糖及壳聚糖季按盐抑制霉菌的生长,对皮革绿色防霉剂开发具有实际意义。     

酸奶中污染酵母菌和霉菌的分离及鉴定

以室温放置直至变质的市售酸奶为样品,从中分离出2株酵母菌和4株霉菌,分别命名为Y1、Y2、M1、M2、M3、M4。酵母菌采用形态学和26SrDNAD1/D2区序列分析鉴定,确定Y1为乳酸克鲁维酵母(Kluyveromyces lactis),Y2为马克思克鲁维酵母(Kluyveromyces marxianus)。霉菌经菌落及菌体形态学鉴定,确定M1、M2、M4为青霉(Penicillum),M3为白地霉(Geotrichum candidum)。     

开放体系下霉菌7对偶氮染料的吸附降解

 研究开放体系下霉菌7菌丝体对偶氮染料的吸附降解作用。考察了菌体培养时间、碳氮源投加量、菌丝体投加量、吸附降解时间、菌丝体重复利用等对染料吸附降解的影响。结果表明,培养36 h的菌丝体,能在葡萄糖2.5 g/L ,NaNO30.5 g/L ,KH2PO4 1.0 g/L ,MgSO4 0.5 g/L的含染料培养基中生长并吸附降解染料。对经霉菌7处理后的染料培养液进行紫外光谱分析和实验现象观察,表明霉菌7对酸性紫红染料的去除以降解脱色为主,而对活性艳红染料的去除以吸附脱色为主。在开放体系中该霉菌表现出了较好的生长优势、成球性、可重复利用性和一定的抗杂菌污染能力。     

Penicillium camemberti and Penicillium roqueforti enhance the growth and survival of Shiga toxin-producing Escherichia coli O157 under mild acidic conditions

The effects of secondary starter molds of common mold-ripened cheeses on the Shiga toxin-producing Escherichia coli (STEC) O157 were assessed in 3 model systems. In the 1st model, 8 STEC O157 strains were incubated in the spent culture of Penicillium camemberti or Penicillium roqueforti under mild acidic conditions at 25 °C. In the spent cultures of the mold at pH 4.8 to 5.0, the lag times of STEC O157 growth were significantly shorter than those observed in fresh medium. Analyses of the spent culture of P. camemberti showed that the causative agents of the growth enhancement were produced by the mold in response to an acidic environment and were not fully inactivated in heat treatment. In the 2nd model, P. camemberti and STEC O157 were cocultured in acidified milk at 25 °C. The population of STEC O157 reached 10(8) CFU/mL in the presence of the mold, whereas the population steadily declined in the absence of the mold. Although this growth enhancement was partially attributable to alkalization by the mold, it was observed even when the pH of this model was stabilized. In the 3rd model, 2 STEC O157 strains were incubated in the spent cultures of molds at pH 4.5 at 10 °C. In the spent culture, proportions of injured cells were significantly lower and D values were significantly higher than those in control, except one STEC O157 strain in the spent culture of P. camemberti. These results showed that the molds could enhance the growth and survival of STEC O157 by changing the environment. Practical Application: This study demonstrated that molds in foods can improve the growth and survival of the Shiga toxin-producing Escherichia coli O157. Because microbial interactions are ubiquitous in food, our results provide an important insight for understanding the behavior of microorganisms in food.     

新型塑料模具材料的发展及研究

文章综述了塑料模具材料的主要服役条件和失效形式,分别从发展塑料模具材料本身和发展模具表面技术2个方面介绍了塑料模具材料发展现状,并研究指出结合稀土表面技术和纳米表面技术制备的新型塑料模具复合镀层材料能显著提高模具的耐磨性、耐蚀性,降低模具材料的使用成本,具有广阔的发展应用前景。同时提出了采用高能球磨和粉末冶金技术相结合的制备工艺思路。     

手机注塑模嵌件成型试模问题及解决方案

手机上嵌件多,面积大,试模出现质量问题情况多,文章从手机注射成型工艺的特点,针对嵌件收缩率不同,采用3个方向不同的比例;变形问题采用模温、优化冷却调整;金属嵌件定位、装配、连接的问题,采用倒三角形,铆孔专门加强方式解决。最后应用综合案例解决实际问题。