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排序方式: 共有1756条查询结果,搜索用时 62 毫秒
71.
在热轧现场轧制规格切换或工况异常的情况下板凸度控制模型偏差较大,为了提高模型精度,提出了一种基于深度森林的热轧带钢凸度预测模型。深度森林模型融合了集成学习和深度学习的思想,采用了多粒度扫描增加数据特征多样性,采用级联森林逐层处理,使得模型具备强大数据拟合能力。将热轧数据经前期预处理导入模型,并对模型参数进行了网格搜索寻优,对比随机森林模型,深度森林模型的效果更优。基于深度森林的热轧带钢凸度预测模型得到了MSE值为6.537,MAE值为1.587,MAPE值为2.903%和R值为0.985的预测性能。 相似文献
72.
The dynamic mechanical relaxation behavior of Ti_(36.2)Zr_(30.3)Cu_(8.3)Fe_4Be_(21.2) bulk metallic glass with good glass-forming ability was investigated by mechanical spectroscopy. The mechanical relaxation behavior was analyzed in the framework of quasi-point defects model. The experimental results demonstrate that the atomic mobility of the metallic glass is closely associated with the correlation factor χ. The physical aging below the glass transition temperature T g shows a non-Debye relaxation behavior, which could be well described by stretched Kohlrausch exponential equation. The Kohlrausch exponent β_(aging) reflects the dynamic heterogeneities of the metallic glass. Both concentration of "defects" and atomic mobility decrease caused by the in situ successive heating during the mechanical spectroscopy experiments. 相似文献
73.
Wang Lifei Zhang Zhengyong Cao Miao Zhang Hua Han Tingzhuang Wang Hongxia Arthanari Srinivasan Cheng Weili Jinlong Lyu 《JOM Journal of the Minerals, Metals and Materials Society》2019,71(5):1705-1713
JOM - Prestretch deformation of 6.48% with various initial speeds (1 mm/min, 101 mm/min, and 100 mm/min) was carried out at 723 K to improve the formability of... 相似文献
74.
The flow ideality of bubbly microflow remains unclear even though it is vital for the design of microreactors, especially the ideality of bubble swarm microflow for large-scale gas-liquid microreaction processes. This work is the first time to report the ideality analysis of the microbubble swarm in a relatively large microchannel. The bubble swarm microflow has undergone two conditions: quasi-homogeneous plug flow and liquid phase/gas-liquid quasi-homogeneous phase two-phase laminar flow. Both the deviations of void fraction and bubble velocity from the ideal plug flow can divide into two parts, and the two transition points simultaneously happen at the velocity ratio of 1.25. There exists a critical capillary number to maintain the quasi-homogeneous plug flow, which could be regarded as the general laws for the design of gas-liquid microreactors. Finally, a novel model is developed to predict the bubble velocity. This work could be very helpful for the large-scale gas-liquid microreactors design. 相似文献
75.
研究了自蔓延燃烧合成Si3N4粉的氧化处理(在空气气氛中分别于400、600、800℃保温3 h)以及添加的分散剂种类(分别为聚丙烯酸钠、六偏磷酸钠、三聚磷酸钠、木质素磺酸钙)对制备的Si3N4浆料的抗沉降性、ζ电位和黏度的影响。结果表明:1)在空气气氛中于800℃保温3 h氧化处理后,粉体中Si2N2O含量增多;用其制备的浆料的稳定性最好,ζ电位绝对值较大,黏度最小。2)以六偏磷酸钠作为分散剂制备的Si3N4浆料的稳定性较好,ζ电位绝对值最大,黏度最小。3)添加0.021%(w)六偏磷酸钠制备的Si3N4浆料的ζ电位绝对值最大,黏度较小。 相似文献
76.
以三光气和双酚AF为原料,采用界面缩聚法合成双酚AF型聚碳酸酯,得到最佳的聚合条件为:三光气和双酚AF的物质的量之比为1.3∶3,催化剂三乙胺的用量为双酚AF质量的4%,反应温度为35℃,反应时间为60 min。通过傅里叶变换红外吸收光谱、乌氏黏度计、同步热分析仪、热变形/维卡软化温度测试仪及极限氧指数测定仪对制备样品进行了结构和性能表征,结果表明,制备样品为双酚AF型聚碳酸酯,样品的黏均分子量为32000。玻璃化转变温度为164.3℃,热失重5%的温度为440.8℃,热变形温度为149℃、维卡软化温度为157℃,具有较好的耐热性能;极限氧指数为29.5%,具有较好的阻燃性能。样品经碱溶液浸泡后质量损失率较小,耐碱腐蚀性能较好。样品在很多有机溶剂中都有很好的的溶解性。 相似文献
77.
Siliu Lyu Muhammad Adnan Younis Zhibin Liu Libin Zeng Xianyun Peng Bin Yang Zhongjian Li Lecheng Lei Yang Hou 《Frontiers of Chemical Science and Engineering》2022,16(6):777
As an eco-friendly, efficient, and low-cost technique, photoelectrochemical water splitting has attracted growing interest in the production of clean and sustainable hydrogen by the conversion of abundant solar energy. In the photoelectrochemical system, the photoelectrode plays a vital role in absorbing the energy of sunlight to trigger the water splitting process and the overall efficiency depends largely on the integration and design of photoelectrochemical devices. In recent years, the optimization of photoelectrodes and photoelectrochemical devices to achieve highly efficient hydrogen production has been extensively investigated. In this paper, a concise review of recent advances in the modification of nanostructured photoelectrodes and the design of photoelectrochemical devices is presented. Meanwhile, the general principles of structural and morphological factors in altering the photoelectrochemical performance of photoelectrodes are discussed. Furthermore, the performance indicators and first principles to describe the behaviors of charge carriers are analyzed, which will be of profound guiding significance to increasing the overall efficiency of the photoelectrochemical water splitting system. Finally, current challenges and prospects for an in-depth understanding of reaction mechanisms using advanced characterization technologies and potential strategies for developing novel photoelectrodes and advanced photoelectrochemical water splitting devices are demonstrated. 相似文献
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