强磁场下Cu−Co难混溶合金凝固过程中晶体取向和性能的调控

对Cu50Co50合金在不同磁场强度下进行非平衡凝固实验,研究富钴相的取向、显微组织演化和磁性能。结果表明,凝固后相分离的棒状富钴相可以实现排列形态,在5 T强磁场下富钴相的晶体取向为111平行磁场方向。然而,发生二次液−液相分离的富铜相的取向没有受到HMF的显著影响。在0 T磁场下凝固的合金表现出近磁各向同性行为,而在5 T磁场下凝固的合金则表现出磁各向异性行为。合金的饱和磁化强度略有增加,矫顽力相应降低,这与富钴晶体的取向演化行为密切相关。

Effect of high magnetic field on solidification microstructure evolution of a Cu-Fe immiscible alloy

The liquid phase separation behavior and the evolution of the solidification microstructure of a binary Cu_(50)Fe_(50) alloy were investigated under the conditions of without and with a 10 T magnetic field,with different undercooling during the solidification process.Results show that the combined effect of Stokes motion and Marangoni convection leads to the formation of the core-shell structure under the condition without the magnetic field.In addition,specific gravity segregation is reinforced by increasing the undercooling,resulting in Fe-rich phase drifts towards the sample edge.In the 10 T magnetic field,the Fe-rich phase is elongated in the parallel direction of the magnetic field under the action of demagnetization energy due to the difference of static magnetic energy and surface energy.In the vertical direction,through the action of Lorentz force,the convection in the melt is inhibited and Fe-rich phase becomes more dispersed.Meanwhile,the diffusion of the two phases and the coagulation of the Fe-rich phases are also restrained under the magnetic field,therefore,the phase volume fraction of the Fe-rich phase decreases at the same undercooling in the 10 T magnetic field.The magnetic field inhibits the segregation behavior in the vertical direction of the magnetic field,and at the same time,improves the gravitational segregation to a certain extent,which has a very important impact on microstructure regulation.

Ultrasound biomicroscopic imaging demonstrate thinner ciliary body thickness in eyes with angle closure

·AIM:To compare the ciliary body thickness between eyes with primary angle closure(PAC)and primary angle-closure glaucoma(PACG)with the normal eyes,and to investigate the association between ciliary body thickness and ciliary processes situation.·METHODS:In this cross-sectional study,57 patients with PAC/PACG were matched to 57 normal subjects after propensity score matching(PSM)adjusting for age and gender.All subjects underwent conventional ocular examinations and ultrasound biomicroscopy(UBM)examination,among which the patients with PAC/PACG performed the examinations one month after laser peripheral iridotomy(LPI).Quantitative parameters were measured,which included ciliary body thickness at the position of 1 mm posterior to the scleral spur(CBT1),trabecular-ciliary process distance(TCPD)and trabecularciliary process angle(TCA).·RESULTS:Eyes with PAC/PACG presented significantly thinner CBT1,shorter TCPD and smaller TCA(P<0.001)than the normal eyes,both in comparison of the means of four quadrants and in comparisons of each quadrant.After removing images with peripheral anterior synechia(PAS),the same results were also found in comparisons between the two groups.Significant correlations were found between TCPD(R~2=0.537,P<0.001)and TCA(R~2=0.517,P<0.001)with CBT1.·CONCLUSION:Eyes with PAC/PACG have thinner ciliary body thickness and more anteriorly situated ciliary processes.Thinner ciliary body thickness is associated with anterior situation of the ciliary processes.

Early vitrectomy combined with pan retinal photocoagulation, anti-vascular endothelial growth factor, and gradual cyclophotocoagulation for treatment of neovascular glaucoma

To the editor: Neovascular glaucoma (NVG) is refractory glaucoma characterized by neovascularization of iris or anterior chamber angle, which often leads to dramatic elevation of intraocular pressure (IOP) and severe vision loss.[1] Series of studies have been reported regarding managing NVG with anti-vascular endothelial growth factor (VEGF) therapy or in combination with anti-glaucoma surgery.[2,3,4] However, the effect of anti-VEGF seems only temporary and it does not improve the prognosis in the long term.[5] Therefore, pan retinal photocoagulation (PRP) remains necessary for improving long term prognosis.[5] However, it is not easy to complete PRP early in NVG patients due to corneal edema, hyphema, or vitreous hemorrhage. We conducted this prospective interventional case series study to propose a protocol which could confine NVG in an early stage. The aims of our treatment modalities included that controlling IOP immediately, complete PRP as soon as possible, anti-VEGF as adjuvant and controlling residual glaucoma with gradual cyclophotocoagulation.