One of the main disadvantages of combustion synthesis of ceramic/metal composite materials is the relatively high level of porosity present in the products. To synthesize TiC/Al composites with a dense structure, this...One of the main disadvantages of combustion synthesis of ceramic/metal composite materials is the relatively high level of porosity present in the products. To synthesize TiC/Al composites with a dense structure, this paper proposes a novel application of an elevated-temperature Al-melt to directly ignite and simultaneously infiltrate Al-Ti-C preform dipped in the melt. The emphasis was placed on the combustion synthesis process and mi-crostructural evolution of the preform in the melt, by a liquid quenching test combined with the measurement of the temperature history of the dipped preform. The results show that the combustion synthesis process of the preform in the elevated-temperature melt involves a series of reactions, and that higher temperature of the melt is favourable for the formation of TiC. The synthesized TiC/Al composites exhibit a dense structure, which is attributed to the infiltration of the melt into the preform.展开更多
目的利用超声造影(CEUS)定量分析技术获取不同甲状腺结节的定量参数,评价其对低增强型亚急性甲状腺炎(SAT)与甲状腺乳头状癌(PTC)的鉴别诊断价值。方法选择32例SAT患者作为SAT组,其中男性6例,女性26例;年龄36~66岁,平均年龄50.37岁;结...目的利用超声造影(CEUS)定量分析技术获取不同甲状腺结节的定量参数,评价其对低增强型亚急性甲状腺炎(SAT)与甲状腺乳头状癌(PTC)的鉴别诊断价值。方法选择32例SAT患者作为SAT组,其中男性6例,女性26例;年龄36~66岁,平均年龄50.37岁;结节大小6.0~36.7 mm,平均最大径13.54 mm。同期选择经术后病理诊断证实39例PTC患者作为PTC组,其中男性9例,女性30例;年龄33~66岁,平均年龄48.28岁;结节大小7.0~23.0 mm,平均最大径11.94 mm。运用SonoLiver软件分析记录各结节整体(W)、边缘(P)和中央(C)的不同感兴趣区(ROI)的CEUS定量参数,包括最大峰值强度(IMAX)、始增时间(RT)、达峰时间(TTP)和平均渡越时间(mTT),并计算周围正常组织各定量参数与结节不同部位定量参数的相对值(△值),对比分析SAT和PTC两组结节之间CEUS定量参数的差异,并用受试者工作特性(ROC)曲线获得截断值。结果SAT组结节定量参数IMAX_(W)和△mTT_(W)大于PTC组(0.53±0.18 vs 0.43±0.23;P<0.05。-1.26±7.35 vs-1.44±2.38;P<0.05);△TTP_(P)在SAT组小于PTC组(-0.42±0.66 vs 0.06±0.75。P<0.05);SAT组定量参数IMAX_(C)、△RT_(C)及△mTT_(C)均高于PTC组(0.49±0.19 vs 0.31±0.28;P<0.05。0.24±0.62 vs-0.28±1.11;P<0.05。1.31±4.32 vs-1.62±4.35;P<0.05)。ROC曲线分析显示定量参数IMAX_(C)及△mTT_(C)的最佳截断值分别为0.27和0.50,曲线下面积分别为0.849和0.837。结论CEUS定量分析有助于低增强型SAT与PTC的鉴别,有一定的临床应用价值。展开更多
基金Financially supported by the Foundation for Excellent Youth of Wuhan City (No. 20015005028) and the Opening Foundation of State Key Lab of Advanced Technology for Materials Synthesis and Processing.
文摘One of the main disadvantages of combustion synthesis of ceramic/metal composite materials is the relatively high level of porosity present in the products. To synthesize TiC/Al composites with a dense structure, this paper proposes a novel application of an elevated-temperature Al-melt to directly ignite and simultaneously infiltrate Al-Ti-C preform dipped in the melt. The emphasis was placed on the combustion synthesis process and mi-crostructural evolution of the preform in the melt, by a liquid quenching test combined with the measurement of the temperature history of the dipped preform. The results show that the combustion synthesis process of the preform in the elevated-temperature melt involves a series of reactions, and that higher temperature of the melt is favourable for the formation of TiC. The synthesized TiC/Al composites exhibit a dense structure, which is attributed to the infiltration of the melt into the preform.
文摘目的利用超声造影(CEUS)定量分析技术获取不同甲状腺结节的定量参数,评价其对低增强型亚急性甲状腺炎(SAT)与甲状腺乳头状癌(PTC)的鉴别诊断价值。方法选择32例SAT患者作为SAT组,其中男性6例,女性26例;年龄36~66岁,平均年龄50.37岁;结节大小6.0~36.7 mm,平均最大径13.54 mm。同期选择经术后病理诊断证实39例PTC患者作为PTC组,其中男性9例,女性30例;年龄33~66岁,平均年龄48.28岁;结节大小7.0~23.0 mm,平均最大径11.94 mm。运用SonoLiver软件分析记录各结节整体(W)、边缘(P)和中央(C)的不同感兴趣区(ROI)的CEUS定量参数,包括最大峰值强度(IMAX)、始增时间(RT)、达峰时间(TTP)和平均渡越时间(mTT),并计算周围正常组织各定量参数与结节不同部位定量参数的相对值(△值),对比分析SAT和PTC两组结节之间CEUS定量参数的差异,并用受试者工作特性(ROC)曲线获得截断值。结果SAT组结节定量参数IMAX_(W)和△mTT_(W)大于PTC组(0.53±0.18 vs 0.43±0.23;P<0.05。-1.26±7.35 vs-1.44±2.38;P<0.05);△TTP_(P)在SAT组小于PTC组(-0.42±0.66 vs 0.06±0.75。P<0.05);SAT组定量参数IMAX_(C)、△RT_(C)及△mTT_(C)均高于PTC组(0.49±0.19 vs 0.31±0.28;P<0.05。0.24±0.62 vs-0.28±1.11;P<0.05。1.31±4.32 vs-1.62±4.35;P<0.05)。ROC曲线分析显示定量参数IMAX_(C)及△mTT_(C)的最佳截断值分别为0.27和0.50,曲线下面积分别为0.849和0.837。结论CEUS定量分析有助于低增强型SAT与PTC的鉴别,有一定的临床应用价值。
