To carry the heavy loadings of the railroad, iron was adopted for covered bridges, at first for only part of the truss, in either vertical or diagonal members, and later for the whole truss.
The main reason for this lack of understanding is that the dynamical behavior of the whole assembly depends critically upon joint conditions, especially under heavy loadings.
Nevertheless, the recent failures in some existing urban rail systems and their station facilities in Hong Kong, Shenzhen, Guangzhou, Shanghai, and Beijing have caused great concerns on how reliable urban rail systems are, particularly due to heavy loadings on station facilities.
The relation between voltage and load was established with loads from 49 to 490 N. The maximum relative errors in light and heavy loadings estimation are 8.0% and 1.36%.
The V1, V2, V3 and V6 have similar heavy loadings for PC1.
A few temporally-based variables showed the heaviest loadings on CVA axes; generally, shorter primary notes with fewer pulses corresponded to greater pulse rates and number of secondary notes.
The loading plots provide the weight of each spectral region, showing that most metabolites positively contribute to PC1, with lactate, glucose, acetate, creatine and pyruvate having the heaviest loadings.
It seems likely that selection acting on DNA GC content may drive the observed difference; PC2, PC3 and PC4 all contain heavy loadings for GC content, a fundamental property of DNA, and, in PCA analyses, extant standing variation in species tended to fall along a common line roughly parallel with variation in GC content in all cases.
However, the second metabolite principal component (metpc2) is mildly correlated with each of the first four expression principal components (0.003 < P < 0.04; Table S2), which suggests that the metabolites with heavy loadings for metpc2 are the most likely to be tied mechanistically to changes in gene expression (e.g., potential cofactors or upstream regulators of gene transcription).
