Eckstrom-adcock iron carbide(Fe_(7)C_(3))is considered to be the main constituent of the Earth’s inner core due to its low shear wave velocity.However,the crystal structure of Fe_(7)C_(3)remains controversial and its...Eckstrom-adcock iron carbide(Fe_(7)C_(3))is considered to be the main constituent of the Earth’s inner core due to its low shear wave velocity.However,the crystal structure of Fe_(7)C_(3)remains controversial and its thermoelastic properties are not well constrained at high temperature and pressure.Based on the first-principles simulation method,we calculate the relative phase stability,equation of state,and sound velocity of Fe_(7)C_(3)under core condition.The results indicate that the orthorhombic phase of Fe_(7)C_(3)is stable under the core condition.While Fe_(7)C_(3)does reproduce the low shear wave velocity and high Poisson’s ratio of the inner core,its compressional wave velocity and density are 12%higher and 6%lower than those observed in seismic data,respectively.Therefore,we argue that carbon alone cannot completely explain the thermal properties of the inner core and the inclusion of other light elements may be required.展开更多
目的:探讨胸腔镜辅助肋骨接骨板(Rib bone plate,RBP)治疗外伤性多发肋骨骨折(Trauma rib fracture,TRF)的临床疗效。方法:选取天津市北辰医院收治的TRF患者68例,其中胸腔镜辅助RBP手术组31例,非手术组37例,非手术组即行多头胸带及胸部...目的:探讨胸腔镜辅助肋骨接骨板(Rib bone plate,RBP)治疗外伤性多发肋骨骨折(Trauma rib fracture,TRF)的临床疗效。方法:选取天津市北辰医院收治的TRF患者68例,其中胸腔镜辅助RBP手术组31例,非手术组37例,非手术组即行多头胸带及胸部护板外固定治疗。分析两组治疗后床上坐起时间、下床活动时间、住院时间、痊愈时间;两组治疗后第1、4、7、10天的视觉模拟评分(VAS);两组使用止痛剂频次。结果:腔镜组治疗后床上坐起时间、下床活动时间、住院时间、痊愈时间均显著短于非手术组(P<0.05);1周后胸腔镜组VAS分值显著小于非手术组(P<0.05);治疗后1周后,腔镜组的PaO_2显著高于非手术组(P<0.05);而并发症(12.9%)明显小于非手术组(54.1%)(P<0.05)。结论:采用胸腔镜RBP法治疗胸部创伤肋骨骨折,可有效缩短卧床时间、减少止痛药物用量及并发症发生率,促进患者愈合,极大地提高了患者生活质量,及早回到工作岗位,适合临床广泛应用。展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.41904085,41874103,and 42274124).
文摘Eckstrom-adcock iron carbide(Fe_(7)C_(3))is considered to be the main constituent of the Earth’s inner core due to its low shear wave velocity.However,the crystal structure of Fe_(7)C_(3)remains controversial and its thermoelastic properties are not well constrained at high temperature and pressure.Based on the first-principles simulation method,we calculate the relative phase stability,equation of state,and sound velocity of Fe_(7)C_(3)under core condition.The results indicate that the orthorhombic phase of Fe_(7)C_(3)is stable under the core condition.While Fe_(7)C_(3)does reproduce the low shear wave velocity and high Poisson’s ratio of the inner core,its compressional wave velocity and density are 12%higher and 6%lower than those observed in seismic data,respectively.Therefore,we argue that carbon alone cannot completely explain the thermal properties of the inner core and the inclusion of other light elements may be required.
文摘目的:探讨胸腔镜辅助肋骨接骨板(Rib bone plate,RBP)治疗外伤性多发肋骨骨折(Trauma rib fracture,TRF)的临床疗效。方法:选取天津市北辰医院收治的TRF患者68例,其中胸腔镜辅助RBP手术组31例,非手术组37例,非手术组即行多头胸带及胸部护板外固定治疗。分析两组治疗后床上坐起时间、下床活动时间、住院时间、痊愈时间;两组治疗后第1、4、7、10天的视觉模拟评分(VAS);两组使用止痛剂频次。结果:腔镜组治疗后床上坐起时间、下床活动时间、住院时间、痊愈时间均显著短于非手术组(P<0.05);1周后胸腔镜组VAS分值显著小于非手术组(P<0.05);治疗后1周后,腔镜组的PaO_2显著高于非手术组(P<0.05);而并发症(12.9%)明显小于非手术组(54.1%)(P<0.05)。结论:采用胸腔镜RBP法治疗胸部创伤肋骨骨折,可有效缩短卧床时间、减少止痛药物用量及并发症发生率,促进患者愈合,极大地提高了患者生活质量,及早回到工作岗位,适合临床广泛应用。
