298,991 research outputs found
Dynamic Response Modeling of Long Cable Steel Bridge for Structural Health Monitoring
No full textStructural health monitoring is becoming a hot research direction in civil engineering. Considering the importance of long cable steel bridges in local transportation and field economic development, strong attention has been paid to structural health analysis to monitor the integrity, durability and reliability of the bridges. Long cable steel bridges are vulnerable to fatigue damage. Local test method, adopted in a number of fatigue damage analysis for short and/or medium bridge, could not be used for long cable bridge fatigue analysis as long cable bridges have many structural properties making inspection, instrumentation and testing of them very difficult. Finite Element Method (FEM), recommended as a rigorous method for fatigue damage analysis by British Standard, is proposed in this paper to analyze fatigue damage for a practical long cable steel bridge under traffic loadings. To this end, an effective Finite Element (FE) model of the Tsing Ma Bridge (TMB) in Hong Kong, embodying the properties of almost all the structural members is developed. Verification of the efficiencies of the model for bridge modal analysis and bridge dynamic response modeling are presented. The computed results are compared with, and found to match closely, online measured data. It shows the constructed bridge finite element model is efficient for structural health analysis
Interface-Engineered Li<sub>7</sub>La<sub>3</sub>Zr<sub>2</sub>O<sub>12</sub>-Based Garnet Solid Electrolytes with Suppressed Li-Dendrite Formation and Enhanced Electrochemical Performance
No full textHigh grain-boundary resistance, Li-dendrite formation, and electrode/Li interfacial resistance are three major issues facing garnet-based solid electrolytes. Herein, interfacial architecture engineering by incorporating 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl) imide (BMP-TFSI) ionic liquid into a garnet oxide is proposed. The “soft” continuous BMP-TFSI coating with no added Li salt generates a conducting network facilitating Li+ transport and thus changes the ion conduction mode from point contacts to face contacts. The compacted microstructure suppresses Li-dendrite growth and shows good interfacial compatibility and interfacial wettability toward Li metal. Along with a broad electrochemical window larger than 5.5 V and an Li+ transference number that practically reaches unity, LiNi0.8Co0.1Mn0.1O2/Li and LiFePO4/Li solid-state batteries with the hybrid solid electrolyte exhibit superior cycling stability and low polarization, comparable to those with commercial liquid electrolytes, and excellent rate capability that is better than those of Li-salt-based ionic-liquid electrolytes.Accepted Author ManuscriptRST/Storage of Electrochemical Energ
Platinum-group elements and geochemical characteristics of the Permian continental flood basalts in the Tarim Basin, northwest China: Implications for the evolution of the Tarim Large Igneous Province
No full textAbstract not availableYin-Qi Li, Zi-Long Li, Ya-Li Sun, M. Santosh, Charles H. Langmuir, Han-Lin Chen, Shu-Feng Yang, Zhong-Xing Chen, Xing Y
Characterizing Deleterious Genomic Mutations in The Presence of Overdominance (a Computer Simulation Approach)
No full textMost mutations with observable phenotypic effects are harmful. Characterizing Deleterious Genomic Mutations (DGMs) is essential in testing the numerous theories that have been developed to explain some fundamental biological phenomena. The mutation-accumulation (M-A) approach has been the predominant method of characterizing DGMs during the past few decades. Two alternatives to the labor- and time-consuming M-A approach, the inbreeding depression approach and the fitness moments approach, have been developed recently. Applying these two approaches is hampered because both depend on the assumption that the standing genetic variation in natural populations is solely due to mutation-selection (M-S) balance. According to this assumption, overdominance does not contribute to heterosis and standing genetic variation. The extent to which this assumption is valid is unknown. In this dissertation, I investigated the statistical properties and the robustness of these two alternative methods in the presence of overdominant mutations using computer simulations. To ensure that the computer simulations could be conducted at relatively controlled levels, two important indices (a and P) and associated analytical derivations were developed to characterize the relative contribution of overdominant mutations to heterosis and standing genetic variation in relation to the genomic parameters of these mutations. These two indices provide a standard for selecting proper input parameters of DGMs and overdominant mutations for computer simulations in this study. They also provide a basis for investigating a number of issues related to the contribution of dominant and overdominant mutations to inbreeding depression and standing genetic variation in natural populations. It is revealed that the contributions of overdominant mutations to heterosis and standing genetic variation are monotonic, but not linearly proportional to each other. Computer simulations and data analyses were performed to study the effects of overdominant mutations on characterizing DGMs with different degrees of violation of the M-S balance assumption in large equilibrium populations in the presence of overdominant mutations. For dominant mutations, estimates for U (DGM rate) are upwardly biased and those for h (mean dominance coefficient) and s (mean selection coefficient) are downwardly biased when additional overdominant mutations are present. However, the degrees of biases generally are moderate and largely depend on the magnitude of the contributions of overdominant mutations to heterosis and standing genetic variation. In addition, under variable mutation effects that usually cause U and s to be underestimated, the estimates of U and 5 are not. always biased in the presence of overdominant mutations. These results provide a basis for correcting inferences of DGM parameters in natural populations. They also alleviate the biggest concern of applying the two newly developed approaches and pave the way for reliably estimating properties of DGMs.ProQuest Traditional Publishing Optionx, 107 leave
Frankfurt book fair: cancelled prize ceremony for Palestinian author is part of a long history of political zigzagging
No full textFirst paragraph: The Frankfurt Buchmesse, or book fair, is the world’s largest publishing industry gathering, attracting thousands of exhibitors every October. On one level, it’s a business event focused on creating buzz for forthcoming bestsellers, trading rights and discussing industry developments. On another, it’s a public celebration of books and the values associated with them.https://theconversation.com/frankfurt-book-fair-cancelled-prize-ceremony-for-palestinian-author-is-part-of-a-long-history-of-political-zigzagging-21574
Short-term Breakdown and Long-term Failure in Nanodielectrics: A Review
No full textNanodielectrics, which are concentrated in polymer matrix incorporating nanofillers, have received considerable attention due to their potential benefits as dielectrics. In this paper, short-term breakdown and long-term failure properties of nanodielectrics have been reviewed. The characteristics of polymer matrix, types of nanoparticle and its content, and waveforms of the applied voltage are fully evaluated. In order to effectively comment on the published experimental data, a ratio k has been proposed to compare the electric properties of the nanodielectrics with the matrix and assess the effect for nanoparticles doping. There is evidence that the short-term breakdown properties of nanodielectrics show a strong dependence on the applied voltage waveforms. The polarity and the cohesive energy density (CED) of polymer matrix have a dramatic influence on the properties of nanodielectrics. Nanoparticle doped composites show a positive effect on the long-term failure properties, such as ageing resistance and partial discharge (PD) properties of nanocomposites are superior than microcomposites and the matrix. The larger the dielectric constant and CED of the matrix become, the more significant improvements in long-term performance appear. Based on the reported experimental results, we also present our understandings and propose some suggestions for further work
Submillimeter-Sized Bubble Entrapment and a High-Speed Jet Emission during Droplet Impact on Solid Surfaces
No full textWhen a droplet impacts a solid surface, the entrapment of a submillimeter-sized bubble and the emission of a high speed jet can be observed at low impact velocities. In this work, we show that bubble entrapment occurs only on sufficiently hydrophobic surfaces within a narrow range of impact velocities. The bubble is entrapped on hydrophobic surfaces, whereas it is trapped into the top of the droplet on superhydrophobic surfaces. The collapse of the air cavity formed during droplet impact, which is dominated by inertia and influenced by surface wettability, is the cause of the bubble entrapment. The velocity of liquid jets emitted after cavity collapse for drop impact with and without bubble entrapment scales with their sizes according to different power laws, which is explained by simple scaling analyses.</p
Li-Compound Anodes: A Classification for High-Performance Li-Ion Battery Anodes
No full textFour main anode types are generally considered as typical
anodes
for Li-ion batteries (LIBs): Li-metal, carbon-based, alloy-based,
and oxide-based anodes. Although they exhibit satisfactory electrochemical
performance as LIB anodes, they cannot simultaneously satisfy all
key requirements for LIB anodes: high reversible capacity, high initial
Coulombic efficiency (ICE), long cycle life, fast rate capability,
structural stability, and no safety concerns. Here, we suggest Li-compound
anodes as a promising class of high-performance LIB anodes. Three
binary (LiSn, Li2Sb, and LiBi) and three ternary (Li2ZnSb, Li5GeP3, and Li5SnP3) Li compounds were introduced as Li-compound anodes. LiSn
and Li5SnP3 were selected and further modified
into their nanocomposites by solid-state synthetic routes using carbon
sources for high-performance LIB anodes. The Li-compound nanocomposite
anodes exhibited excellent performance and simultaneously fulfilled
all the key requirements for high-performance LIB anodes. Therefore,
Li-compound anodes are expected to be a promising and innovative category
of high-performance LIB anodes
- …
