A combined experimental and computational study was carried out to investigate ballistic performance of laterally preload compressed SiC tile against long rod impact. A 100 x 100 by 20 mm thick SiC tile was pushed int...A combined experimental and computational study was carried out to investigate ballistic performance of laterally preload compressed SiC tile against long rod impact. A 100 x 100 by 20 mm thick SiC tile was pushed into a 5 mm thick steel frame at high temperature of 430 ℃ so that after cool down to room temperature, the lateral preload compressive stress was developed in the SiC tiles. Depth of penetration tests of the SiC tiles with and without pre-stress were performed, where tungsten alloy long rods at a nominal velocity of 1240 m/s were launched to hit the SiC tiles backed by the steel blocks. Compared with the SiC tiles without any pre-stress, the pre-compressed SiC tiles were found to reduce significantly the residual penetration in the backing block. Simulations were carried out using the LS-dyna hydrocode,taking account of preload stress. The simulations showed that the lateral preload compression strengthened the intact SiC tiles and dwell occurred in the early penetration stage, eroding the striking long rod efficiently.展开更多
目的：回顾性分析 Tile C 型骨盆骨折患者死亡相关的危险因素。方法2010年1月至2014年12月我院收治的 Tile C 型骨盆骨折患者139例,收集资料包括术前一般情况、伤后就诊时间、休克指数、各类创伤评分、最低氧合指数、伤后6 h 乳酸清除率...目的：回顾性分析 Tile C 型骨盆骨折患者死亡相关的危险因素。方法2010年1月至2014年12月我院收治的 Tile C 型骨盆骨折患者139例,收集资料包括术前一般情况、伤后就诊时间、休克指数、各类创伤评分、最低氧合指数、伤后6 h 乳酸清除率等,采用多因素 Logistic 回归分析死亡相关危险因素。结果入院后死亡41例（29.5%）,其中入院后48 h 内死亡36例（25.9%）。多因素回归分析显示,休克指数＆gt;2（OR=2.591,95%CI 1.041~4.216）、损伤严重程度评分（ISS）≥25分（OR=47.96,95%CI 15.89~147.23）、改良创伤评分（RTS）≤8分（OR=6.917,95%CI 1.147-13.862）、格拉斯哥昏迷评分（GCS）〈9分（OR=4.172,95%CI 2.962~6.268）、最低氧合指数〈200（OR=117.016,95%CI 51.011~176.032）、伤后6 h 乳酸清除率〈10%（OR=2.785,95%CI 1.191~4.892）,以及合并头部损伤（OR=6.302,95%CI 2.270~13.175）或胸部损伤（OR=12.233,95%CI 5.193~33.985）是骨盆骨折患者死亡相关危险因素（P 〈0.01）。早期行血管栓塞治疗有助于降低死亡风险（OR=0.887,95%CI 0.875~0.899）。结论创伤评分高,出现严重休克、昏迷、氧合指数下降和6 h 乳酸清除率降低,合并头部和胸部损伤是导致 Tile C 型骨盆骨折患者死亡的危险因素。展开更多
文摘A combined experimental and computational study was carried out to investigate ballistic performance of laterally preload compressed SiC tile against long rod impact. A 100 x 100 by 20 mm thick SiC tile was pushed into a 5 mm thick steel frame at high temperature of 430 ℃ so that after cool down to room temperature, the lateral preload compressive stress was developed in the SiC tiles. Depth of penetration tests of the SiC tiles with and without pre-stress were performed, where tungsten alloy long rods at a nominal velocity of 1240 m/s were launched to hit the SiC tiles backed by the steel blocks. Compared with the SiC tiles without any pre-stress, the pre-compressed SiC tiles were found to reduce significantly the residual penetration in the backing block. Simulations were carried out using the LS-dyna hydrocode,taking account of preload stress. The simulations showed that the lateral preload compression strengthened the intact SiC tiles and dwell occurred in the early penetration stage, eroding the striking long rod efficiently.
文摘目的：回顾性分析 Tile C 型骨盆骨折患者死亡相关的危险因素。方法2010年1月至2014年12月我院收治的 Tile C 型骨盆骨折患者139例,收集资料包括术前一般情况、伤后就诊时间、休克指数、各类创伤评分、最低氧合指数、伤后6 h 乳酸清除率等,采用多因素 Logistic 回归分析死亡相关危险因素。结果入院后死亡41例（29.5%）,其中入院后48 h 内死亡36例（25.9%）。多因素回归分析显示,休克指数＆gt;2（OR=2.591,95%CI 1.041~4.216）、损伤严重程度评分（ISS）≥25分（OR=47.96,95%CI 15.89~147.23）、改良创伤评分（RTS）≤8分（OR=6.917,95%CI 1.147-13.862）、格拉斯哥昏迷评分（GCS）〈9分（OR=4.172,95%CI 2.962~6.268）、最低氧合指数〈200（OR=117.016,95%CI 51.011~176.032）、伤后6 h 乳酸清除率〈10%（OR=2.785,95%CI 1.191~4.892）,以及合并头部损伤（OR=6.302,95%CI 2.270~13.175）或胸部损伤（OR=12.233,95%CI 5.193~33.985）是骨盆骨折患者死亡相关危险因素（P 〈0.01）。早期行血管栓塞治疗有助于降低死亡风险（OR=0.887,95%CI 0.875~0.899）。结论创伤评分高,出现严重休克、昏迷、氧合指数下降和6 h 乳酸清除率降低,合并头部和胸部损伤是导致 Tile C 型骨盆骨折患者死亡的危险因素。
