Comparative investigations of ternary thermite Al/Fe_(2)O_(3)/CuO and Al/Fe_(2)O_(3)/Bi_(2)O_(3) from pyrolytic,kinetics and combustion behaviors

To develop new energy enhancement energetic materials with great combustion performance and thermal stability,two kinds of ternary thermite,Al/Fe_(2)O_(3)/CuO and Al/Fe_(2)O_(3)/Bi_(2)O_(3),were prepared and analyzed via mechanical ball milling.The samples were characterized by SEM,XRD,TG-DSC,constant volume and constant pressure combustion experiments.The first exothermic peaks of Al/Fe_(2)O_(3)/CuO and Al/Fe_(2)O_(3)/Bi_(2)O_(3) appear at 579°C and 564.5°C,respectively.The corresponding activation energies are similar.The corresponding mechanism functions are set as G(a) = [-ln(1-a)]^(3/4) and G(a) =[-ln(1-a)]2/3,respectively,which belong to the Avrami-Erofeev equation.Al/Fe_(2)O_(3)/CuO has better thermal safety.For small dose samples,its critical temperature of thermal explosion is 121.05°C higher than that of Al/Fe_(2)O_(3)/Bi_(2)O_(3).During combustion,the flame of Al/Fe_(2)O_(3)/CuO is spherical,and the main products are FeAl_(2)O_(4) and Cu.The flame of Al/Fe_(2)O_(3)/Bi_(2)O_(3)is jet-like,and the main products are Al_(2)O_(3),Bi and Fe.Al/Fe_(2)O_(3)/Bi_(2)O_(3)has better ignition and gas production performance.Its average ignition energy is 4.2 J lower than that of Al/Fe_(2)O_(3)/CuO.Its average step-up rate is 28.29 MPa/s,which is much higher than 6.84 MPa/s of Al/Fe_(2)O_(3)/CuO.This paper provides a reference for studying the thermal safety and combustion performance of ternary thermite.

增生型糖尿病视网膜病变玻璃体切割术后再出血的治疗和观察

目的:探讨糖尿病视网膜病变玻璃体切割术后再出血(postvitrectomy diabetic vitreous haemorrhage,PDVH)的治疗方法及疗效。方法:回顾性分析2015-09/2017-06于我院行玻璃体切割术治疗后发生PDVH的PDR患者12例12眼,首先进行保守治疗,对出血量大、保守治疗效果差的患者进行手术治疗(前房冲洗、玻璃体腔灌洗、再次玻璃体切割术或联合白内障手术等),观察并分析患者治疗情况。结果:本组患者发生PDVH的时间为首次玻璃体切割术后1d～10mo(平均61.58±92.69d),其中早期PDVH患者8眼,晚期PDVH患者4眼。2眼患者行保守治疗2wk～1mo后出血吸收,10眼保守治疗无明显好转或眼内压(IOP)持续升高者再次行手术治疗,其中2眼行单纯前房冲洗术,8眼行玻璃体腔灌洗术(2眼联合白内障手术、1眼联合硅油注入术),7眼明确眼底情况后术中补充视网膜激光光凝。至末次随访,所有玻璃体腔再出血均吸收,9眼视力较治疗前提高。结论:多种原因可引起PDVH,可通过调控血糖、改进手术技巧、及时对症治疗等方法采取适当措施治疗,提高患者视力。