Model for atomization droplet size and energy distribution ratio at the distal end of an electrostatic nozzle

Electrostatic atomization minimum quantity lubrication(EMQL)employs the synergistic effect of multiple physical fields to atomize minute quantities of lubricant.This innovative methodology is distinguished by its capacity to ameliorate the atomization attributes of the lubricant substantially,which subsequently augments the migratory and infiltration proficiency of the droplets within the complex and demanding milieu of the cutting zone.Compared with the traditional minimum quantity lubrication(MQL),the EMQL process is further complicated by the multiphysical field influences.The presence of multiple physical fields not only increases the complexity of the forces acting on the liquid film but also induces changes in the physical properties of the lubricant itself,thus making the analysis of atomization characteristics and energy distribution particularly challenging.To address this objective reality,the current study has conducted a meticulous measurement of the volume average diameter,size distribution span,and the percentage concentration of inhalable particles of the charged droplets at various intercept positions of the EMQL nozzle.A predictive model for the volume-averaged droplet size at the far end of the EMQL nozzle was established with the observed statistical value F of 825.2125,which indicates a high regression accuracy of the model.Furthermore,based on the changes in the potential energy of surface tension,the loss of kinetic energy of gas,and the electric field work at different nozzle orifice positions in the EMQL system,an energy distribution ratio model for EMQL was developed.The energy distribution ratio coefficients under operating conditions of 0.1 MPa air pressure and 0 to 40 kV voltage on the 20 mm cross-section ranged from 3.094‰to 3.458‰,while all other operating conditions and cross-sections had energy distribution ratios below 2.06‰.This research is expected to act as a catalyst for the progression of EMQL by stimulating innovation in the sphere of precision manufacturing,providing theoretical foundations,and offering practical guidance for the further development of EMQL technology.

康柏西普治疗早产儿视网膜病变患儿屈光状态改变的临床研究

目的:观察玻璃体腔注射康柏西普(IVC)治疗早产儿视网膜病变(ROP)患儿后的屈光状态改变,探讨ROP患儿屈光状态与注药次数、孕周、出生体质量、眼轴、视网膜血管发育情况之间的相关性。方法:前瞻性临床研究。选取2017年4月至2021年6月就诊于潍坊眼科医院并诊断为“2型ROP阈值前病变”的患儿64例(127眼)。根据其病情严重程度按需行IVC治疗,以治疗次数分为注药0次(A组)共22例(43眼)、注药1次(B组)共30例(53眼)、注药2次(C组)共18例(31眼),在其矫正胎龄3、6、12个月时,观察屈光状态,记录等效球镜度(SE)、散光、眼轴、视网膜血管分区等情况。3组SE比较采用单因素方差分析,散光比较采用Kruskal-Wallis非参数检验,SE与孕周、出生体质量、眼轴及视网膜血管分区的关系采用Pearson及Spearman相关性分析。结果:矫正胎龄3个月和6个月时,3组SE及散光差异均无统计学意义;矫正胎龄12个月时,3组SE及散光差异均有统计学意义(F=6.59,P=0.002;H=7.39,P=0.025)。进一步两两比较,A组与B组、A组与C组之间SE差异有统计学意义(P=0.006;P=0.007),A组与C组散光差异有统计学意义(P=0.020)。矫正胎龄12个月时,3组屈光不正发生率、近视率差异无统计学意义,散光发生率差异有统计学意义(χ^(2)=8.96,P=0.011)。进一步两两比较,A组与C组、B组与C组差异有统计学意义(χ^(2)=7.08,P=0.008;χ^(2)=6.82,P=0.009)。矫正胎龄3个月时,SE与孕周(r=-0.18,P=0.043)、出生体质量(r=-0.19,P=0.032)、眼轴(r=-0.26,P=0.003)、视网膜血管分区(r=-0.20,P=0.023)均呈负相关;矫正胎龄6个月、12个月时,SE与眼轴呈负相关(r=-0.30,P=0.001)。结论:矫正胎龄12个月时,IVC治疗后ROP患儿远视储备低于自发消退的ROP患儿,重复注药对ROP患儿短期屈光状态无显著影响。