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61.
QIN WEN RONGCHAO MA QIAO DONG YAO XIN 《Journal of Food Processing and Preservation》2006,30(6):670-683
Mango (Mangifera indica L. cv. Hongxiangya and Wacheng) was chosen to study the effect of postharvest biological characters in different storage conditions. The determining items included respiratory rate, total sugar, vitamin C (Vc) content, firmness, polyphenol oxidase (PPO) and peroxidase (POD). The results showed that both 8 and 11C were the better storage temperatures, and the storage life would last 50 days in this situation. The respiration rate increased quickly between the 16th to the 22nd days; the peak values were the 28th and 25th days at 8C for Hongxiangya and Wacheng, respectively. The flesh firmness decreased dramatically at 6 days after harvest. Total sugar content, Vc content, PPO and POD increased at first and then decreased. The color changed from green to yellow with the increase of carotenoids content. After treatment with thiabendozole and iprodione, the number of rot fruits was markedly lower than the other treatments. The best temperature is 11 and 14C for Hongxiangya and Wacheng, respectively. The rot rate is 6.77 and 8.33% with 1,000‐ppm iprodine treatment after 50‐days storage. 相似文献
62.
研究了钛铁矿选择氯化制取人造金红石反应的Fe-Ti-C-O2-Cl2系平衡图,计算了氧与某些氯化物相互作用的自由能变化,采用“通氧一步选择氯化法”,解决了选择氯化“自热”反应持续进行的技术关键,对反应参数进行了实验室,半工业和工业化生产试验研究,研究证明,选择氯化过程的动力学模型是“固体颗粒粒度保持不变的缩核反应模型”,动力学区的活性能为34.33kJ/mol;扩散区的活化能为0.80kJ/mol,研究开发的无筛板沸腾氯化炉可以长期稳定地连续运转,生产出的人造金红石品位为92.10%,经摇床和磁选,品位达到95%,床层单位炉产能达12.4t/(m2.d),该工艺和设备已成功地应用于工业生产。 相似文献
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目前市场对中厚板的订单具有个性化和多样化的特点,而对于不同强度级别的钢板,化学成分设计往往是不同的,这样会增加不同钢坯冶炼之间衔接的时间及化学成分控制的难度,导致冶炼成本增加,工序复杂化。结合市场需求与生产实际,采用同一Q390低合金高强度钢板坯,通过不同的控轧控冷工艺,对Q390C和Q420C两种强度级别热轧钢板进行了试制。结果表明,通过控轧控冷技术,可以充分发挥细晶强化作用,采用同一Q390低合金高强度钢板坯实现了Q390C和Q420C两个强度级别热轧钢板的柔性生产。试制生产的两种钢板,强塑性及0 ℃冲击功均满足标准要求,Q420C钢板屈服强度达441 MPa以上,抗拉强度达579 MPa以上。采用柔性轧制技术,降低了Q420C高强钢板的生产成本。 相似文献
66.
The influence of 0.1-0.6 at.-%RE additions (RE= La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Yb) on themechanical properties of Pd was studied. All above RE additions increased not only the strengthproperties at ambient temperature but also the tensile strength, creep rupture time and activation en-ergy at high temperatures, simultaneously increased the elongation of Pd. In the range of dilute con-centration, the strength properties of Pd-RE alloy enhanced linearly with RE concentration. Whenthe strength properties of Pd-RE alloys were normalized at 0.1 at.-%RE, it was found that light REelements had stronger effect on the properties of Pd than heavy RE, whereas Eu, Yb, Ce had anoma-lous effect. In all Pd-RF alloys, Pd-Eu alloy had the highest strength properties, successively Pd-Yband Pd-Ce alloy. The effect mechanisms of RE in alloy, such as purifying impurities, increasingrecrystallization temperature, refining grain size. expanding crystal lattice, increasing dislocation den-sity and decreasing stacking fault energy, forming stable RE oxidation by internal oxidation, and soon, were observed. They were strengthening sensitive factors. The influence of the factors onstrength properties and elongation of Pd was discussed. 相似文献
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68.
Study on Numerical Simulation of Mold Filling and Solidification Processes under Pressure Conditions
The mold filling and solidification simulation for the high pressure die casting (HPDC) and low pressure die casting (LPDC) processes were studied.A mathematical model considering the turbulent flow and heat transfer phenomenon during the HPDC process has been established and paralled computation technique was used for the mold filling simulation of the process.The laminar flow characteristics of the LPDC process were studied and a simplified model for the mold filling process of wheel castings has been developed.For the solidification simulation under pressure conditions,the cyclic characteristics and the complicated boundary conditions were considered and techniques to improve the computational efficiency are discussed.A new criterion for predicting shrinkage porosity of Al alloy under low pressure condition has been developed in the solidification simulation process. 相似文献
70.
The numerical si mulation of combustion processhas been performed[1,2],but thereis still no suitabletemperature measuring technique for three-di men-sional analysis[3].Nowadays,the radiant i mage pro-cessing technique has been developed at home and a-broad[4,5].The relation between radiant i mage andpulverized coal combustion process in blast furnaceraceway was studiedin present work withthis meth-od to examine three-di mensional temperature distri-butionin blast furnace raceway.1Radiant Image… 相似文献