臭氧果蔬保鲜销售包装的实验研究

介绍了臭氧果蔬保鲜技术的作用机理及其特点;在分析果蔬保鲜包装技术要求的基础上,应用臭氧技术结合包装技术方法,在常温下对西红柿、豆角进行了臭氧保鲜实验研究,对腐烂率、减重率、硬度、可溶性固形物含量、还原糖含量、总酸、VC含量、叶绿素含量等指标进行了测试,结果表明:以上果蔬的保鲜期至少延长2周以上,对现代销售中的果蔬保鲜包装具有指导意义.     

一种有效制备果树高分子量DNA的方法

与一般植物叶片相比,果树叶片因富含多酚和多糖类物质,制备高分子量ＤＮＡ比较困难。我们建立了一个个从果树叶片制备高分子量ＤＮＡ的有效程序,按照该方法制备的五种果树ＨＭＷＤＮＡ,无叶绿体和线粒体ＤＮＡ污染,无大量的非特异小片段的混杂,有利于限制性酶切分析和大片段基因组文库的构建。     

Active and passive stabilization of body pitch in insect flight

Flying insects have evolved sophisticated sensory–motor systems, and here we argue that such systems are used to keep upright against intrinsic flight instabilities. We describe a theory that predicts the instability growth rate in body pitch from flapping-wing aerodynamics and reveals two ways of achieving balanced flight: active control with sufficiently rapid reactions and passive stabilization with high body drag. By glueing magnets to fruit flies and perturbing their flight using magnetic impulses, we show that these insects employ active control that is indeed fast relative to the instability. Moreover, we find that fruit flies with their control sensors disabled can keep upright if high-drag fibres are also attached to their bodies, an observation consistent with our prediction for the passive stability condition. Finally, we extend this framework to unify the control strategies used by hovering animals and also furnish criteria for achieving pitch stability in flapping-wing robots.     

不同终压对火龙果切片真空预冷效果的影响

研究了不同终压(400～800Pa)下真空预冷对火龙果切片降温速率、失水率以及预冷后在4℃冷藏温度下72h内的持水性、pH值、硬度和色泽指标的影响。结果表明:终压变化对降温速率和失重率的影响都不大,然而,适当的升高终压却可以延缓持水性、pH值、硬度及色泽的变化。综合比较得知,预冷终压在700～800Pa时火龙果切片在4℃冷藏温度下产品货架期最长,为60h。     

准球形葡萄预冷时间的研究

果蔬预冷是冷藏链中一个重要环节,适当的预冷时间能保证果蔬质量。通过对巨峰葡萄在预冷时的传热分析,建立了集总参数法模型来估算葡萄中心温度达到冷库温度时所需要的时间,并通过实验进行了验证。结果表明当冷库内空气流速达到一定时(大于1．1m/s),采用定性尺寸R,集总参数法能够很好地估算葡萄预冷时间,为农业生产中形状类似于葡萄的果蔬预冷时间提供了依据。     

Influence of fungicide treatment and storage conditions on mould and yeast activity on “Satsuma” mandarin

The activity of mould and yeast population on the surface of ‘Satsuma’ mandarin was studied at four temperatures (2, 4, 10 and 20 °C) and two relative humidity (RH) levels (80 and 93%) on fruits washed and on fruits washed and treated with a fungicide mixture (1200 ppm thiabendazole + 800 guazatine + 400 ppm prochloraz), stored for 20 and 40 days. The lowest final microbial counts (CFU) were for the fruits treated and stored at 2 °C and 93% RH and the highest counts were for fruits stored at 20 °C and 93% RH regardless of fungicide treatment. Throughout the storage period, yeast and Cladosporium spp. were predominant in the microbial counts and generally showed reducing trends. The fungicide treatment was very efficient and persistent. The absence of antifungal treatment and the increase of RH levels caused a greater rise of CFU than the increase of the storage period or temperature. An increase in the CFU values with the increase of RH was observed in untreated fruits. The treatment of ‘Satsuma’ fruits with the fungicide mixture, followed by cold storage at 2 °C and 93% RH, extended the storage period at least 40 days.     

我国果蔬低温贮藏保鲜发展状况与展望

综述我国果蔬低温贮藏保鲜发展状况,包括机械冷藏、机械气调冷藏、机械减压冷藏、机械湿冷冷藏和机械冰库冷藏等冷藏场所及设施。介绍数字化与智能化控制、环境友好型制冷工质及制氮方法及多种温度和气调使用形式等保鲜科技及技术支持与新技术开发。提出研究果蔬物流保鲜全程控制体系、完善果蔬冷链流通体系和冷藏库建设以物流现代化为基础的展望。     

Tamarind Fruit Fiber and Glass Fiber Reinforced Polyester Composites

Polyester-based hybrid composites were developed by combining the tamarind fruit (Tf) and glass fibers into a polyester matrix. Hardness, impact strength, frictional coefficient, and chemical resistance of hybrid composites with and without alkali treatments were studied. Variation of the aforementioned mechanical properties and chemical resistance was studied with different fiber lengths, such as 1, 2, and 3 cm. A 9 vol% of the tamarind and glass fibers was reinforced into the polyester matrix. The aforementioned mechanical properties were optimally improved at 2-cm fiber length when compared with 1- and 3-cm fiber lengths. Chemical resistance was also significantly improved for all chemicals except toluene. A 3°C rise in decomposition temperature while a 2°C rise in glass transition temperature was observed from TGA and DSC micrograms, respectively.     

Psychological and Social Predictors of Changes in Fruit and Vegetable Consumption Over 12 Months Following Behavioral and Nutrition Education Counseling.

This study assessed psychological and social factors predicting 12-month changes in fruit and vegetable consumption achieved by 271 men and women from a low-income population randomized to brief behavioral and nutrition education counseling. Greater increases in fruit and vegetable intake were achieved in the behavioral than in the nutrition education condition (1.49 vs. 0.87 portions per day, p=.021). Increases were predicted by baseline social support for dietary change but not by baseline psychological measures. However, short-term (8-week) changes in dietary self-efficacy, encouragement, anticipated regret, perceived benefits, and knowledge of recommended intake predicted 12-month changes in fruit and vegetable consumption independently of gender, age, ethnicity, income, and baseline intake. These factors accounted for 51% of the superiority of behavioral counseling over nutrition education. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

钢铁企业重点科研项目实施的探索与思考

介绍了科研项目管理的概念，决策立项的意义。以钢铁企业实施重点科研项目的管理为例，对于科研项目过程中的产学研相结合模式的实践、项目管理模式与团队建设探索、协调处理生产与研发的关系、项目成果转化评估等方面进行了探讨。