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The electric shoegear-conductor rail system (the shoe-rail system) is one of the electric energy collection devices for metro vehicles. A good interaction performance between the electric shoegear and the conductor rail is essential to ensure the current collection quality and operational safety. The conductor rail irregularities and vehicle-track excitation (induced by track irregularities) are the major disturbances to the shoe-rail interaction. Only the vertical effect of the vehicle-track excitation has been considered in previous studies, which cannot reproduce the realistic behavior of the shoe-rail system. To address this deficiency, this work attempts to build a spatial vehicle-shoe-rail system coupling model, including the disturbances from both the conductor rail irregularities and vehicle-track excitations. The numerical accuracy is verified by comparison with the measurement data collected from Guangzhou Metro Line 5 (Jiaokou to Wenchong section). Then, the effects of conductor rail irregularities, speed, shoe-rail structure parameters, and track irregularities on the interaction performance of the electric shoegear-conductor rail system are analyzed. The results show that the maximum contact force exceeds the safety threshold at a speed of over 120 km/h. The frequency analysis of the contact force at different speeds indicates the necessity to avoid the resonance caused by the match between the span passage frequency and the dominant natural frequency. The stochastic analysis indicates a visible dispersion in contact force standard deviation excited by track irregularities. The dispersion increases from 2.2% to 21.8% with the degradation of the track quality from level 6 to level 1. The statistical maximum of contact force will exceed the safety threshold with poor track quality.

Previous studies are inconclusive on the relationships between BLKgene polymorphisms and clinical features of systemic lupus erythematosus (SLE). The present study aimed to estimate association between BLKloci and SLE clinical features in Chinese population. Associations between BLKsingle-nucleotide polymorphisms (SNPs) and susceptibility to SLE in this study were estimated using data of 1205 health controls previously reported in the same population. And a total of 814 SLE patients recruited from two different sources according with ACR criteria were analyzed for genotype–phenotype associations. A meta-analysis was conducted of the associations between BLKloci and renal disorder in SLE. The expression quantitative trait locus (eQTL) data were also extracted from the public databases for the selected SNPs. Significant associations were observed between these SNPs and susceptibility to SLE. In addition, the data showed that rs2618479 and rs7812879 were associated with renal disorder [OR = 1.51 (95% CI: 1.15, 1.99) and 1.61 (95% CI: 1.21, 2.14), Pcorr= 0.033 and 0.011, respectively] and proteinuria [OR = 1.47 (95% CI: 1.12, 1.95) and 1.52 (95% CI: 1.14, 2.03), Pcorr= 0.048 and 0.040, respectively]. The consistent associations were observed in two independent centers as well as new cases group. The result of meta-analysis for rs2618479 was also significant [OR = 1.35 (95% CI: 1.12, 1.62)]. In addition, bioinformatics analysis demonstrated that the two SNPs were significantly associated with the expression of BLKin whole blood and several immune cells. Our data support that variant loci of BLKare associated with presence of renal disorder in patients with SLE.