Silicon carbide(SiC) has been widely concerned for its excellent overall mechanical and physical properties, such as low density, good thermal-shock behavior, high temperature oxidation resistance, and radiation resis...Silicon carbide(SiC) has been widely concerned for its excellent overall mechanical and physical properties, such as low density, good thermal-shock behavior, high temperature oxidation resistance, and radiation resistance; as a result, the SiC-based materials have been or are being widely used in most advanced fields involving aerospace, aviation, military, and nuclear power. Joining of SiC-based materials(monolithic SiC and SiCf/SiC composites) can resolve the problems on poor processing performance and difficulty of fabrication of large-sized and complex-shaped components to a certain extent, which are originated from their high inherent brittleness and low impact toughness.Starting from the introduction to SiC-based materials, joining of ceramics, and joint strength characterization, the joining of SiC-based materials is reviewed by classifying the as-received interlayer materials, involving no interlayer, metallic, glass-ceramic, and organic interlayers. In particular, joining processes(involving joining techniques and parameter conditions), joint strength,interfacial microstructures, and/or reaction products are highlighted for understanding interfacial behavior and for supporting development of application-oriented joining techniques.展开更多
由于PPI网络数据的无尺度和小世界特性,使得目前对此类数据的聚类算法效果不理想.根据PPI网络的拓扑结构特性,本文提出了一种基于连接强度的蚁群优化(Joint Strength based Ant Colony Optimization,JSACO)聚类算法,该算法引入了连接强...由于PPI网络数据的无尺度和小世界特性,使得目前对此类数据的聚类算法效果不理想.根据PPI网络的拓扑结构特性,本文提出了一种基于连接强度的蚁群优化(Joint Strength based Ant Colony Optimization,JSACO)聚类算法,该算法引入了连接强度的概念对蚁群聚类算法中的拾起/放下规则加以改进,以连接强度作为拾起规则,对结点进行聚类,并根据放下规则放弃部分不良数据,产生最终聚类结果.最后采用了MIPS数据库中的PPI数据进行实验,将JSACO算法与PPI网络数据的其他聚类算法进行比较,聚类结果表明JSACO算法正确率高,时间开销低.展开更多
首次提出了用于汽车生产中分瓣模压印连接接头强度和失效形式的预测方法。根据接头静力学测试中的颈部断裂失效和上下板拉脱失效两种失效形式分别建立了压印接头的两个强度预测公式,2pπ2N N NF A R t t()和2p pπt b s F R,公式以接头...首次提出了用于汽车生产中分瓣模压印连接接头强度和失效形式的预测方法。根据接头静力学测试中的颈部断裂失效和上下板拉脱失效两种失效形式分别建立了压印接头的两个强度预测公式,2pπ2N N NF A R t t()和2p pπt b s F R,公式以接头颈部厚度Nt和镶嵌量Ut为重要的中间变量。强度预测公式表明:对于颈部断裂的压印接头,颈部厚度值tN越大,接头强度越高;对于拉脱失效的压印接头,接头强度取决于颈部厚度tN和镶嵌量tU,两者之和越大,接头强度越高,并且镶嵌量对接头强度的影响与颈部厚度相比更大。对颈部厚度变化范围为0.35mm^0.56mm、镶嵌量变化范围为0.045mm^0.45mm的15种组合接头,根据强度预测公式计算了接头强度,并进行了拉伸-剪切试验。将计算结果与试验结果进行对比,结果表明二者吻合较好,最大接头强度误差为8.9%。这说明本文建立的接头强度预测公式能够准确地预测压印接头拉伸-剪切过程的强度和破坏形式。展开更多
基金supported by the National Natural Science Foundation of China (No. 51572112)the National Key R&D Program of China (No. 2017YFB0310400)+3 种基金the 333 Talents Project (No. BRA2017387)Six Talent Peaks Project (No. TD-XCL-004)Innovation/Entrepreneurship Program ([2015]26)Qing Lan Project ([2016]15) of Jiangsu Province
文摘Silicon carbide(SiC) has been widely concerned for its excellent overall mechanical and physical properties, such as low density, good thermal-shock behavior, high temperature oxidation resistance, and radiation resistance; as a result, the SiC-based materials have been or are being widely used in most advanced fields involving aerospace, aviation, military, and nuclear power. Joining of SiC-based materials(monolithic SiC and SiCf/SiC composites) can resolve the problems on poor processing performance and difficulty of fabrication of large-sized and complex-shaped components to a certain extent, which are originated from their high inherent brittleness and low impact toughness.Starting from the introduction to SiC-based materials, joining of ceramics, and joint strength characterization, the joining of SiC-based materials is reviewed by classifying the as-received interlayer materials, involving no interlayer, metallic, glass-ceramic, and organic interlayers. In particular, joining processes(involving joining techniques and parameter conditions), joint strength,interfacial microstructures, and/or reaction products are highlighted for understanding interfacial behavior and for supporting development of application-oriented joining techniques.
文摘由于PPI网络数据的无尺度和小世界特性,使得目前对此类数据的聚类算法效果不理想.根据PPI网络的拓扑结构特性,本文提出了一种基于连接强度的蚁群优化(Joint Strength based Ant Colony Optimization,JSACO)聚类算法,该算法引入了连接强度的概念对蚁群聚类算法中的拾起/放下规则加以改进,以连接强度作为拾起规则,对结点进行聚类,并根据放下规则放弃部分不良数据,产生最终聚类结果.最后采用了MIPS数据库中的PPI数据进行实验,将JSACO算法与PPI网络数据的其他聚类算法进行比较,聚类结果表明JSACO算法正确率高,时间开销低.
文摘首次提出了用于汽车生产中分瓣模压印连接接头强度和失效形式的预测方法。根据接头静力学测试中的颈部断裂失效和上下板拉脱失效两种失效形式分别建立了压印接头的两个强度预测公式,2pπ2N N NF A R t t()和2p pπt b s F R,公式以接头颈部厚度Nt和镶嵌量Ut为重要的中间变量。强度预测公式表明:对于颈部断裂的压印接头,颈部厚度值tN越大,接头强度越高;对于拉脱失效的压印接头,接头强度取决于颈部厚度tN和镶嵌量tU,两者之和越大,接头强度越高,并且镶嵌量对接头强度的影响与颈部厚度相比更大。对颈部厚度变化范围为0.35mm^0.56mm、镶嵌量变化范围为0.045mm^0.45mm的15种组合接头,根据强度预测公式计算了接头强度,并进行了拉伸-剪切试验。将计算结果与试验结果进行对比,结果表明二者吻合较好,最大接头强度误差为8.9%。这说明本文建立的接头强度预测公式能够准确地预测压印接头拉伸-剪切过程的强度和破坏形式。
