Seismic Performance Assessment of a Pin-bearing Restraint System for Curved Bridge

The traditional restraint systems limit the deformation of curved bridge under temperature load, which results in radial and tangential secondary internal forces in the bridge. This paper proposes a pin-bearing restraint system (PBRS) for curved bridge, which can relax the rotational deformation of curved bridge under temperature load. Its configuration and working mechanism are illustrated. The finite element model of a curved bridge with PBRS is established using ANSYS software, and nonlinear time history analysis is conducted. The pounding force and pounding number between pin and slot under ground motion are analyzed. The pin stiffness, the gap and the ratio of upper structure mass to lower structure mass are selected for parametric study. The results show that the pounding force and pounding number present dramatic changes with pin stiffness. As the pin stiffness increases, the pounding force presents a logarithmic linear tendency, and the pounding number shows a reduce tendency. Gap has little influence on pounding force and pounding number. The radial pounding force and pounding number increase with the increase of mass ratio

Evaluation of soil fertility of the shelter-forest land along the Tarim Desert Highway

To study the changes of soil fertility of the shelter-forest land along the Tarim Desert Highway, soils from the forest land were collected at the layers of 0-10 cm, 10-20 cm, 20-30 cm. Different soil fertility parameters were measured, and quantitative evaluation of soil fertility was performed by the soil integrated fertility index (IFI). The main results show that the construction of the shelter forest along the Tarim Desert Highway improved the soil physical structure, increased soil porosity and enhanced water-holding capacity. With the increase of plantation time of the shelter forest, soil microbial biomass C, N, P and the activities of six types of enzyme were enhanced, which promoted the accumulation and transformation of soil nutrients of the forest land. Consequently, the soil nutrients in 12-year-old forest land were much higher than in the newer ones and drifting sand. However, soil salt content of the older forest land was higher owing to the drip-irrigation with salt water. Through the comprehensive evaluation, we found that soil fertility index in the forest land was enhanced with the forest age, and it had close correlations with the growth indices of the forest trees. In summary, construction of the shelter-forest along the Tarim Desert Highway accelerated the improvement of aeolian soil in the forest land, and the soil fertility improved year by year. We conclude that the forest trees grow normally under the stress of the present drip-irrigation with salt water

A sub-convex similarity-based model updating method considering multivariate uncertainties

This paper proposes an innovative model updating technique that thoroughly considers the interrelations among multivariate output features. The approach involves developing a novel uncertainty quantification metric, termed Sub-Convex Similarity. A specialised data preprocessing operator is proposed to reveal the inherent distributional attributes of multivariate datasets through a sequencing pre-processing. To manage the inherent randomness associated with sample location dispersion, we propose a binning algorithm based on the equal-bin-datapoints principle. This method allows for the quantification of multidimensional stochastic data without the need to calculate the joint probability distribution function. Utilising convex hull theory, sub-regional boundaries are established within each bin to reveal multivariate dataset characteristics. Sub-Convex Similarity serves as a metric for quantifying both interval-based and stochastic uncertainties, measuring discrepancies between simulated and experimental datasets in the context of both interval and stochastic model updating. The proposed model updating framework employs the sparrow search algorithm, a swarm intelligence-based optimization mechanism. The effectiveness and broad applicability of this approach are demonstrated through case studies involving a three-degree-of-freedom mass-spring system and a finite element model of a satellite, addressing multivariate uncertainties

MAPK and phenylpropanoid metabolism pathways involved in regulating the resistance of upland cotton plants to Verticillium dahliae

IntroductionVerticillium dahliae causes a serious decline in cotton yield and quality, posing a serious threat to the cotton industry. However, the mechanism of resistance to V. dahliae in cotton is still unclear, which limits the breeding of resistant cultivars.MethodsTo analyze the defense mechanisms of cotton in response to V. dahliae infection, we compared the defense responses of two upland cotton cultivars from Xinjiang (JK1775, resistant; Z8,susceptible) using transcriptome sequencing at different infection stages.ResultsThe results revealed a significant differential expression of genes in the two cotton cultivars post V. dahliae infection, with the number of DEGs in JK1775 being higher than that in Z8 at different infection stages of V. dahliae. Interestingly, the DEGs of both JK1775 and Z8 were enriched in the MAPK signaling pathway in the early and late stages of infection. Importantly, the upregulated DEGs in both cultivars were significantly enriched in all stages of the phenylpropanoid metabolic pathway. Some of these DEGs were involved in the regulation of lignin and coumarin biosynthesis, which may be one of the key factors contributing to the resistance of upland cotton cultivars to V. dahliae in Xinjiang. Lignin staining experiments further showed that the lignin content increased in both resistant and susceptible varieties after inoculation with V. dahliae.DiscussionThis study not only provides insights into the molecular mechanisms of resistance to Verticillium wilt in Xinjiang upland cotton but also offers important candidate gene resources for molecular breeding of resistance to Verticillium wilt in cotton