Sand-dust storm is a type of disastrous weather, typically occurring in arid and semi-arid climates. This study selected a region in the hinterlands of the Taklimakan Desert, called the Tazhong region, as the experime...Sand-dust storm is a type of disastrous weather, typically occurring in arid and semi-arid climates. This study selected a region in the hinterlands of the Taklimakan Desert, called the Tazhong region, as the experimental area to quantitatively estimate the particle concentrations of sand-dust storms using the boundary layer wind-profiling radar. We thoroughly studied the radar echo signals and reflectivity factor features during the sand-dust storms. The results indicate that（1） under sand-dust storm conditions, boundary layer wind-profiling radar cannot capture the complete information regarding horizontal wind velocity and direction, but it can obtain the backscattering intensity of sand-dust storms; and（2） during sand-dust storms particle size distributions in the surface layer closely resemble log-normal distributions, with sand-dust particles sizes of 90–100 μm accounting for the maximum particle probability. Retrieved particle size distributions at heights of 600, 800, and 1000 m follow log-normal distributions, and the expected value of particle diameter decreases gradually with increasing height. From the perspective of orders of magnitude, the retrieved results for particle number concentrations and mass concentrations are consistent with previous aircraft-detected results, indicating that it is basically feasible to use boundary layer wind-profiling radar to quantitatively detect the particle concentrations of dust storms.展开更多
目的探讨应用3D打印多孔钛合金假体修复四肢长骨无菌性大段骨缺损的临床可行性及有效性。方法2017年12月至2022年12月应用3D打印多孔钛合金假体治疗四肢长骨无菌性骨缺损患者13例,男7例、女6例,年龄(52.6±11.5)岁(范围35~72岁)。...目的探讨应用3D打印多孔钛合金假体修复四肢长骨无菌性大段骨缺损的临床可行性及有效性。方法2017年12月至2022年12月应用3D打印多孔钛合金假体治疗四肢长骨无菌性骨缺损患者13例,男7例、女6例,年龄(52.6±11.5)岁(范围35~72岁)。骨缺损部位:肱骨2例、桡骨1例、股骨5例和胫骨6例,其中1例患者同时合并股骨与胫骨缺损。13例患者均为骨折内固定术后发生骨不连,其中肥大性骨不连5例、萎缩性骨不连8例;内固定手术距骨缺损修复手术的间隔时间为(20.1±3.6)个月(范围16.5~26.6个月)。通过大体观察、影像学评估、上肢功能评分(disability of arm shoulder and hand,DASH)、下肢功能评分(lower extremity functional scale,LEFS)、患者满意度评价等评估临床疗效。结果13例患者清创后骨缺损长度为(11.7±4.5)cm(范围6.0~20.6 cm),植入假体长度为(12.9±5.3)cm(范围6.1~22.9 cm);术后(14.8±6.5)d(范围2~22 d)开始部分或完全负重。13例均获得随访,随访时间(18.3±12.5)个月(范围13~58个月)。X线片示假体及内固定物持续稳定,新生骨逐渐由骨缺损断面爬行生长并与假体表面形成稳定的骨整合,均未发生假体移位及断裂。末次随访时,3例上肢骨缺损患者的DASH评分分别为8.9、10.5和11.2分,10例下肢骨缺损患者的LEFS评分为(49.6±5.9)分(范围38~56分)。所有假体均未发生明显沉降与松动,患者满意度评分为(9.8±0.1)分(范围9.6~9.9分)。结论应用3D打印多孔钛合金假体修复四肢长骨无菌性大段骨缺损术后患者可早期负重及功能锻炼,患肢功能恢复显著,患者满意度高。展开更多
基金supported by the National Natural Science Foundation of China (41775030, 41575008, 11302111, 11562017)the China Research Foundation for Desert Meteorology (SQJ2014003)the China Postdoctoral Science Foundation
文摘Sand-dust storm is a type of disastrous weather, typically occurring in arid and semi-arid climates. This study selected a region in the hinterlands of the Taklimakan Desert, called the Tazhong region, as the experimental area to quantitatively estimate the particle concentrations of sand-dust storms using the boundary layer wind-profiling radar. We thoroughly studied the radar echo signals and reflectivity factor features during the sand-dust storms. The results indicate that（1） under sand-dust storm conditions, boundary layer wind-profiling radar cannot capture the complete information regarding horizontal wind velocity and direction, but it can obtain the backscattering intensity of sand-dust storms; and（2） during sand-dust storms particle size distributions in the surface layer closely resemble log-normal distributions, with sand-dust particles sizes of 90–100 μm accounting for the maximum particle probability. Retrieved particle size distributions at heights of 600, 800, and 1000 m follow log-normal distributions, and the expected value of particle diameter decreases gradually with increasing height. From the perspective of orders of magnitude, the retrieved results for particle number concentrations and mass concentrations are consistent with previous aircraft-detected results, indicating that it is basically feasible to use boundary layer wind-profiling radar to quantitatively detect the particle concentrations of dust storms.
文摘目的探讨应用3D打印多孔钛合金假体修复四肢长骨无菌性大段骨缺损的临床可行性及有效性。方法2017年12月至2022年12月应用3D打印多孔钛合金假体治疗四肢长骨无菌性骨缺损患者13例,男7例、女6例,年龄(52.6±11.5)岁(范围35~72岁)。骨缺损部位:肱骨2例、桡骨1例、股骨5例和胫骨6例,其中1例患者同时合并股骨与胫骨缺损。13例患者均为骨折内固定术后发生骨不连,其中肥大性骨不连5例、萎缩性骨不连8例;内固定手术距骨缺损修复手术的间隔时间为(20.1±3.6)个月(范围16.5~26.6个月)。通过大体观察、影像学评估、上肢功能评分(disability of arm shoulder and hand,DASH)、下肢功能评分(lower extremity functional scale,LEFS)、患者满意度评价等评估临床疗效。结果13例患者清创后骨缺损长度为(11.7±4.5)cm(范围6.0~20.6 cm),植入假体长度为(12.9±5.3)cm(范围6.1~22.9 cm);术后(14.8±6.5)d(范围2~22 d)开始部分或完全负重。13例均获得随访,随访时间(18.3±12.5)个月(范围13~58个月)。X线片示假体及内固定物持续稳定,新生骨逐渐由骨缺损断面爬行生长并与假体表面形成稳定的骨整合,均未发生假体移位及断裂。末次随访时,3例上肢骨缺损患者的DASH评分分别为8.9、10.5和11.2分,10例下肢骨缺损患者的LEFS评分为(49.6±5.9)分(范围38~56分)。所有假体均未发生明显沉降与松动,患者满意度评分为(9.8±0.1)分(范围9.6~9.9分)。结论应用3D打印多孔钛合金假体修复四肢长骨无菌性大段骨缺损术后患者可早期负重及功能锻炼,患肢功能恢复显著,患者满意度高。
