包装码垛设备的发展及选型与能力计算

根据近年来国内外适用于石化行业大中型塑料等装置系统设备的发展情况,简要介绍高速称量机、高速包装机、高速码垛机的型式、主要结构特点,以及国内外包装码垛系统的发展概况。对于包装码垛系统设计与选型的能力教育处。提出了考虑操作稳定备用系数1.16的建议。     

尿素热解制氨系统设计问题探讨

本文针对华能北京热电有限公司尿素热解制氨系统设计中遇到的袋装尿素上料问题、尿素溶液在输送过程中的结晶问题及尿素管道U型布置问题等,采取了行之有效的改进措施,达到很好的效果,并积累了宝贵经验。为同类电力企业实施烟气脱硝技术改造提供参考。     

套袋对芒果果实采后品质和后熟的影响

在芒果(Mangifera indica L.cv.Zihua)的生长期内,分别用纸袋和无纺布袋进行套袋处理,以不套袋果实作为对照。果实采收后于20℃,85%～95%RH的环境下进行贮藏,并定期取样进行观察测定。结果表明,生长期套袋的"紫花"芒果果实果面的锈斑发生率和锈斑指数都比对照果实低,套袋对芒果果实的可溶性固形物和可滴定酸含量、硬度、呼吸强度几乎没有影响,但套袋处理更容易使果实着色。布袋的效果优于纸袋。     

蜜柚套袋种植中氯硝胺的迁移规律研究

采用气相色谱-串联质谱法检测套袋纸及蜜柚中氯硝胺的含量,并通过田间试验研究了氯硝胺从五种套袋纸向蜜柚不同部位的迁移规律。结果表明四种含有氯硝胺的套袋纸处理的蜜柚全果中氯硝胺的残留浓度随着套袋时间的延长逐渐升高,到第40 d达到最高值。以第70 d蜜柚正常成熟采收为计,全果中氯硝胺的最终残留浓度与套袋纸中氯硝胺的初始含量的相关关系符合预测方程y=-0.048×e（-x/26.156）+0.048,当全果中氯硝胺的最终残留浓度为0.01 mg/kg时,套袋纸中氯硝胺的初始临界含量为6.126 mg/kg。蜜柚套袋全过程中,五种套袋蜜柚果肉均未检出氯硝胺残留。通过提前10 d摘袋,全果中氯硝胺的残留量可降低23.8%。本研究为揭示蜜柚中氯硝胺残留污染的来源提供了科学依据,为今后蜜柚套袋种植以及套袋纸生产管理具有重要的指导意义。     

Preharvest bagging with wavelength-selective materials enhances development and quality of mango (Mangifera indica L.) cv. Nam Dok Mai #4

BACKGROUND: Preharvest bagging has been shown to improve development and quality of fruits. Different light transmittance bags showed different effects on fruit quality. This study presents the benefits of using newly developed plastic bagging materials with different wavelength‐selective characteristics for mangoes (cv. Nam Dok Mai #4). Mangoes were bagged at 45 days after full bloom (DAFB) and randomly harvested at 65, 75, 85, 95, and 105 DAFB. The bags were removed on the harvest days. The wavelength‐selective bags (no pigment, yellow, red, blue/violet, blue) were compared with the Kraft paper bag with black paper liner, which is currently used commercially for several fruits, and with non‐bagging as a control. RESULTS: Bagging significantly (p?0.05) reduced diseases and blemishes. Mango weight at 95 DAFB was increased approximately 15% by VM and V plastic bagging, as compared to paper bagging and control. Plastic bagging accelerated mango ripening as well as growth. Plastic‐bagged mangoes reached maturity stage at 95 DAFB, while non‐bagged mangoes reached maturity stage at 105 DAFB. Paper bagging resulted in a pale‐yellow peel beginning at 65 DAFB, while plastic bagging improved peel glossiness. CONCLUSION: Preharvest bagging with different wavelength‐selective materials affected mango development and quality. Bagging mangoes with VM and V materials could reduce peel defects and diseases, increase weight, size, and sphericity, improve peel appearance, and shorten the development periods of mangoes. The results suggest a favorable practice using the newly developed VM and V plastic bags in the production of mangoes, and possibly other fruits as well. Copyright © 2010 Society of Chemical Industry     

Improving bagging performance through multi-algorithm ensembles

Working as an ensemble method that establishes a committee of classifiers first and then aggregates their outcomes through majority voting, bagging has attracted considerable research interest and been applied in various application domains. It has demonstrated several advantages, but in its present form, bagging has been found to be less accurate than some other ensemble methods. To unlock its power and expand its user base, we propose an approach that improves bagging through the use of multi-algorithm ensembles. In a multi-algorithm ensemble, multiple classification algorithms are employed. Starting from a study of the nature of diversity, we show that compared to using different training sets alone, using heterogeneous algorithms together with different training sets increases diversity in ensembles, and hence we provide a fundamental explanation for research utilizing heterogeneous algorithms. In addition, we partially address the problem of the relationship between diversity and accuracy by providing a non-linear function that describes the relationship between diversity and correlation. Furthermore, after realizing that the bootstrap procedure is the exclusive source of diversity in bagging, we use heterogeneity as another source of diversity and propose an approach utilizing heterogeneous algorithms in bagging. For evaluation, we consider several benchmark data sets from various application domains. The results indicate that, in terms of F1-measure, our approach outperforms most of the other state-of-the-art ensemble methods considered in experiments and, in terms of mean margin, our approach is superior to all the others considered in experiments.     

果实采前套袋对热带亚热带果树果实品质和耐贮性的影响

果实采前套袋是提高果品的品质和商品价值的有效方式。本文综述了热带、亚热带果树果实采前套袋的研究进展与应用现状,果实采前套袋对果实品质、农药残留、重金属含量、成熟期和采后果实耐贮性的影响,同时指出了果实采前套袋存在的问题和今后需进一步研究的领域。     

套袋促进茌梨果实色素的合成及上调PbcrtZ基因的表达

通过测定花后不同时期套袋茌梨果实的外观品质和贮藏期间果实的失重率,确定茌梨最佳套袋时期为花后60 d。以花后60 d套袋的茌梨果实为试材,分析了塑膜袋和无纺布袋处理的果实果皮中叶绿素含量、类黄酮含量和类胡萝卜素含量以及色泽相关差异基因PbcrtZ基因的表达模式。套塑膜袋和无纺布袋的茌梨果实发育阶段的叶绿素含量明显低于未套袋果实,而类黄酮含量以及类胡萝卜素含量在花后180 d明显高于未套袋果实。PbcrtZ基因在套塑膜袋和无纺布袋果实中的表达明显高于未套袋果实,花后180 d分别为对照的4.36倍和3.48倍,与类胡萝卜素含量和类黄酮含量差异一致。因此,塑膜袋和无纺布套袋果实色泽呈黄绿色,未套袋果实呈现绿色,其中无纺布袋处理的果实外观品质和贮藏性明显优于塑膜袋套袋果实。     

基于PLC的全自动计量混合袋装机控制系统的研制

叙述了一种袋装机的设计与实现,详细分析了可编程控制器在袋装机中的应用方式及特点,利用FX2N-32MR对袋装机进行控制,详细讨论了袋装机的输入输出信息,研究了其逻辑关系。实际应用表明:系统获得了良好的控制效果,实现了袋装机全自动计量混合包装的控制目的。     

一种散体物料自动称量装袋机的设计

研制了一种散体物料自动称量装袋机,设备采用由变频器控制的裙边皮带作为供料装置,由弧形闸门实现料层的调节。称量装置设有过渡罩和夹袋斗,过渡罩上的振动电机可有效清除粘附的物料,保证了称量的可靠性。使用结果表明该设备能够很好的适应粉状及颗粒状散体物料的称量充填,当计量值为50kg时,对于粉状物料计量速度为4~5次/min,颗粒状物料可达到5~6次/min,称量误差均小于100g,满足0.2级秤的精度要求。