A multi-inclusion cell model is used to investigate the effect of deformation temperature and whisker rotation on the hot compressive behavior of metal matrix composites with misaligned whiskers. Numerical results sho...A multi-inclusion cell model is used to investigate the effect of deformation temperature and whisker rotation on the hot compressive behavior of metal matrix composites with misaligned whiskers. Numerical results show that deformation temperature influences the work-hardening behavior of the matrix and the rotation behavior of the whiskers. With increasing temperature, the work hardening rate of the matrix decreases, but the whisker rotation angle increases. Both whisker rotation and the increase of deformation temperature can induce reductions in the load supported by whisker and the load transferred from matrix to whisker. Additionally, it is found that during large strain deformation at higher temperatures, the enhancing of deformation temperature can reduce the effect of whisker rotation. Meanwhile, the stress-strain behavior of the composite is rather sensitive to deformation temperature. At a relatively lower temperature （150℃）, the composite exhibits work hardening due to the matrix work hardening, but at relatively higher temperatures （300℃ and above）, the composite shows strain softening due to whisker rotation. It is also found that during hot compression at higher temperatures, the softening rate of the composite decreases with increasing temperature. The predicted stress-strain behavior of the composite is approximately in agreement with the experimental results.展开更多
Based on the principle of piecewise linearization, the incremental forms of microstructure evolution models were integrated into the thermo-mechanical coupled finite element（FE） model to simulate nonlinear microstru...Based on the principle of piecewise linearization, the incremental forms of microstructure evolution models were integrated into the thermo-mechanical coupled finite element（FE） model to simulate nonlinear microstructure evolution during multi-pass hot deformation. This is an unsteady-state deformation where dynamic recrystallization（DRX）, meta-dynamic recrystallization（MDRX）, static recrystallization（SRX） and grain growth（GG） take place during hot deformation or deformation interval. The distributions of deformation and microstructure for cylindrical AZ31 sample during single-pass and double-pass hot compressions were quantitatively calculated and compared with the metallographic observation. It is shown that both the deformation and microstructure are non-uniformly distributed due to the presence of friction between the die and the flat end of sample. The average grain size and its standard deviation under the double-pass hot compression are slightly smaller than those under single-pass compression.The simulated average grain sizes agree well with the experiments, which validates that the developed FE model on the basis of incremental forms of microstructure evolution models is reasonable.展开更多
目的：研究骨疼静胶囊对热板法致小鼠疼痛及对尾部加压法致小鼠疼痛的影响。方法取体重19～22 g雌性小鼠，随机分组；分别灌服大中小剂量骨疼静胶囊混悬液，颈复康颗粒混悬液和同体积的0,．5％CMC。按热板法及尾部加压法测定小鼠痛阈，...目的：研究骨疼静胶囊对热板法致小鼠疼痛及对尾部加压法致小鼠疼痛的影响。方法取体重19～22 g雌性小鼠，随机分组；分别灌服大中小剂量骨疼静胶囊混悬液，颈复康颗粒混悬液和同体积的0,．5％CMC。按热板法及尾部加压法测定小鼠痛阈，并计算痛阈提高值。结果骨疼静胶囊组和颈复康颗粒组可显著提高小鼠痛阈（ P ＜0．01）；骨疼静胶囊组和颈复康颗粒组可显著提高在小鼠30 min和60min 的压痛痛阈（ P ＜0．01）。结论骨疼静胶囊有显著的镇痛作用。展开更多
目的观察子午流注纳子法联合眼罩热敷治疗室性早搏伴失眠的临床疗效。方法将室性早搏伴失眠患者120例,随机分为治疗组、对照组1、对照组2、对照组3,每组30例。治疗组给予子午流注纳子法逢时开穴联合中药安神护目眼罩热敷治疗,对照组1给...目的观察子午流注纳子法联合眼罩热敷治疗室性早搏伴失眠的临床疗效。方法将室性早搏伴失眠患者120例,随机分为治疗组、对照组1、对照组2、对照组3,每组30例。治疗组给予子午流注纳子法逢时开穴联合中药安神护目眼罩热敷治疗,对照组1给予常规针刺治疗,对照组2给予眼罩热敷治疗,对照组3给予常规针刺联合眼罩热敷治疗。观察各组治疗前后24 h Holter室性早搏次数、匹兹堡睡眠质量指数(PSQI)评分变化,并比较各组治疗15 d后、治疗30 d后的临床疗效。结果治疗组治疗30 d后总有效率为93.3%,均高于对照组1的66.7%,对照组2的63.3%和对照组3的70.0%,差异均具有统计学意义(P<0.05)。治疗组治疗后24 h Holter室性早搏次数、PSQI评分与对照组1、对照组2和对照组3比较,差异均具有统计学意义(P<0.05)。结论对室性早搏伴失眠患者采用子午流注纳子法逢时开穴联合中药安神护目眼罩热敷,可以改善患者的临床症状,临床疗效显著。展开更多
基金This study was financially supported by the National Natural Science Foundation of China (No. 50071008).
文摘A multi-inclusion cell model is used to investigate the effect of deformation temperature and whisker rotation on the hot compressive behavior of metal matrix composites with misaligned whiskers. Numerical results show that deformation temperature influences the work-hardening behavior of the matrix and the rotation behavior of the whiskers. With increasing temperature, the work hardening rate of the matrix decreases, but the whisker rotation angle increases. Both whisker rotation and the increase of deformation temperature can induce reductions in the load supported by whisker and the load transferred from matrix to whisker. Additionally, it is found that during large strain deformation at higher temperatures, the enhancing of deformation temperature can reduce the effect of whisker rotation. Meanwhile, the stress-strain behavior of the composite is rather sensitive to deformation temperature. At a relatively lower temperature （150℃）, the composite exhibits work hardening due to the matrix work hardening, but at relatively higher temperatures （300℃ and above）, the composite shows strain softening due to whisker rotation. It is also found that during hot compression at higher temperatures, the softening rate of the composite decreases with increasing temperature. The predicted stress-strain behavior of the composite is approximately in agreement with the experimental results.
基金the funding support from the National Natural Science Foundation of China (Grant No. 51573156, 51675335)
文摘Based on the principle of piecewise linearization, the incremental forms of microstructure evolution models were integrated into the thermo-mechanical coupled finite element（FE） model to simulate nonlinear microstructure evolution during multi-pass hot deformation. This is an unsteady-state deformation where dynamic recrystallization（DRX）, meta-dynamic recrystallization（MDRX）, static recrystallization（SRX） and grain growth（GG） take place during hot deformation or deformation interval. The distributions of deformation and microstructure for cylindrical AZ31 sample during single-pass and double-pass hot compressions were quantitatively calculated and compared with the metallographic observation. It is shown that both the deformation and microstructure are non-uniformly distributed due to the presence of friction between the die and the flat end of sample. The average grain size and its standard deviation under the double-pass hot compression are slightly smaller than those under single-pass compression.The simulated average grain sizes agree well with the experiments, which validates that the developed FE model on the basis of incremental forms of microstructure evolution models is reasonable.
文摘目的：研究骨疼静胶囊对热板法致小鼠疼痛及对尾部加压法致小鼠疼痛的影响。方法取体重19～22 g雌性小鼠，随机分组；分别灌服大中小剂量骨疼静胶囊混悬液，颈复康颗粒混悬液和同体积的0,．5％CMC。按热板法及尾部加压法测定小鼠痛阈，并计算痛阈提高值。结果骨疼静胶囊组和颈复康颗粒组可显著提高小鼠痛阈（ P ＜0．01）；骨疼静胶囊组和颈复康颗粒组可显著提高在小鼠30 min和60min 的压痛痛阈（ P ＜0．01）。结论骨疼静胶囊有显著的镇痛作用。
文摘目的观察子午流注纳子法联合眼罩热敷治疗室性早搏伴失眠的临床疗效。方法将室性早搏伴失眠患者120例,随机分为治疗组、对照组1、对照组2、对照组3,每组30例。治疗组给予子午流注纳子法逢时开穴联合中药安神护目眼罩热敷治疗,对照组1给予常规针刺治疗,对照组2给予眼罩热敷治疗,对照组3给予常规针刺联合眼罩热敷治疗。观察各组治疗前后24 h Holter室性早搏次数、匹兹堡睡眠质量指数(PSQI)评分变化,并比较各组治疗15 d后、治疗30 d后的临床疗效。结果治疗组治疗30 d后总有效率为93.3%,均高于对照组1的66.7%,对照组2的63.3%和对照组3的70.0%,差异均具有统计学意义(P<0.05)。治疗组治疗后24 h Holter室性早搏次数、PSQI评分与对照组1、对照组2和对照组3比较,差异均具有统计学意义(P<0.05)。结论对室性早搏伴失眠患者采用子午流注纳子法逢时开穴联合中药安神护目眼罩热敷,可以改善患者的临床症状,临床疗效显著。
文摘使用田口法探索了影响钒钛磁铁矿热压块抗压强度的重要因子,并通过信噪比分析计算各因子对抗压强度的贡献率,最终给出钒钛磁铁矿热压块的最佳制备条件.实验结果表明,在热压温度、配碳比、煤粉粒度三个影响因素中,煤粉粒度对抗压强度的影响程度最大,其贡献率达到了79.99%,温度和配碳比二者的贡献率分别为15%和3.63%.优化后钒钛磁铁矿热压块的制备参数为热压温度300℃、煤粉粒度<75μm、配碳比1.8.在优化后的参数下进行验证实验,得到的钒钛矿热压块的平均抗压强度达到1 152.1 N.
