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941.
V. G. Tsverava M. Yu. Rusin V. I. Nepovinnykh V. G. Verevka S. P. Borodai A. S. Khamitsaev 《Polymer Science Series C》2007,49(1):74-79
The dependence of the ultimate shear strength of a lithium aluminosilicate ceramic-to-metal adhesive joint with the sealant Viksint U-2-28 on the thermal history of the samples was studied. A temperature threshold for a change in the strength of the adhesive joint was established. Possible mechanisms for the appearance of this threshold in terms of a change in the contribution of different components of the sealant to its adhesion properties, depending on the thermal aging regimes, are discussed. 相似文献
942.
介绍了国产YL-100型自动加药装置功能及其在中国石化茂名石化乙烯工业公司乙烯循环水场的应用情况,结果表明其运行平稳,总磷测试数据可靠,可达到循环水自动加药控制的目的。 相似文献
943.
In this study, the reaction kinetics of asymmetric polymer-polymer interface was experimentally and theoretically studied. A new rheological method correlating the change of rheological property of reactive system with the conversion of the in situ formed copolymers was applied to study the reaction kinetics of PBT/epoxy reactive system. Then, the new method was proved to be useful by comparing its results with that obtained from the conventional endgroup determination method. Moreover, the conversion of PBT/epoxy reactive system from rheological method could be well fitted by the numerical analysis, from which the kinetic constant and the diffusion constant of epoxy in PBT could be determined simultaneously. 相似文献
944.
Shapiro Ya. Z. Zhuchenko O. V. Gaodu A. N. 《Refractories and Industrial Ceramics》1986,27(3-4):159-164
Conclusions The possibility is shown of obtaining lightweight refractories with an operational temperature of 1750°C and having a wide range of properties. The use of these refractories depends on the particular requirements and the conditions of service.Translated from Ogneupory, No. 3, pp. 24–28, March, 1986. 相似文献
945.
946.
沉淀铁催化剂上F-T合成反应的研究 总被引:2,自引:1,他引:2
制备了物相组成为 Quartz- Si O2 ,Hermatite- Fe2 O3 和 Fe2 O3 - Iron Oxide的沉淀铁催化剂 ,研究了该催化剂作用上固定床积分反应器中费托合成反应特性 .发现 2 .6MPa,80 0 h-1,H2 /CO=2 /3,2 60℃~ 2 90℃时 ,随着温度的升高 ,CO和 H2 的转化率增大 ,CO2 选择性减小 ;40 0 h-1,65 0 h-1,80 0 h-1低空速和 2 4 0 0 h-1,32 0 0 h-1,40 0 0 h-1,640 0 h-1高空速时 ,随着空速的升高 ,H2转化率、CO转化率选择性下降 ,CO2 的选择性升高 ;2 80℃ ,2 .6MPa,H2 /CO进料比 2 /3,1 /1 ,2 /1时 ,随着 H2 /CO进料比的增加 ,CO转化率 ,H2 /CO利用比和 CH4选择性都增加 ,H2 转化率和 CO2选择性减小 . 相似文献
947.
948.
949.
950.
Case-based reasoning (CBR) is one of the main forecasting methods in business forecasting, which performs well in prediction and holds the ability of giving explanations for the results. In business failure prediction (BFP), the number of failed enterprises is relatively small, compared with the number of non-failed ones. However, the loss is huge when an enterprise fails. Therefore, it is necessary to develop methods (trained on imbalanced samples) which forecast well for this small proportion of failed enterprises and performs accurately on total accuracy meanwhile. Commonly used methods constructed on the assumption of balanced samples do not perform well in predicting minority samples on imbalanced samples consisting of the minority/failed enterprises and the majority/non-failed ones. This article develops a new method called clustering-based CBR (CBCBR), which integrates clustering analysis, an unsupervised process, with CBR, a supervised process, to enhance the efficiency of retrieving information from both minority and majority in CBR. In CBCBR, various case classes are firstly generated through hierarchical clustering inside stored experienced cases, and class centres are calculated out by integrating cases information in the same clustered class. When predicting the label of a target case, its nearest clustered case class is firstly retrieved by ranking similarities between the target case and each clustered case class centre. Then, nearest neighbours of the target case in the determined clustered case class are retrieved. Finally, labels of the nearest experienced cases are used in prediction. In the empirical experiment with two imbalanced samples from China, the performance of CBCBR was compared with the classical CBR, a support vector machine, a logistic regression and a multi-variant discriminate analysis. The results show that compared with the other four methods, CBCBR performed significantly better in terms of sensitivity for identifying the minority samples and generated high total accuracy meanwhile. The proposed approach makes CBR useful in imbalanced forecasting. 相似文献