Elastoplastic Large Deflection Analysis of Cold-formed Members Using Spline Finite Strip Method

The elastoplastic large deflection behaviour of cold-formed members is analysed by a nonlinear spline finite strip method. The method is developed using the principle of virtual work, based on the total Lagrangian description. It is used to deal with problems of geometric and material nonlinearity. The displacement function of a strip is expressed as the product of transverse interpolation polynomials and longitudinal B3-splines. The effect of arbitrary initial imperfections is taken into consideration. The influence of cold-bending residual stress on the local and overall behaviour of cold-formed lipped angle columns is investigated especially. The numeric examples show that the method possesses such advantages as fewer degrees of freedom, fine continuity, good boundary adaptation, quick computation speed and high accuracy etc

How do China’s lockdown and post-COVID-19 stimuli impact carbon emissions and economic output? Retrospective estimates and prospective trajectories

This paper develops a multi-sector and multi-factor structural gravity model that allows an analytical and quantitative decomposition of the emission and output changes into composition and technique effects. We find that the negative production shock of China's containment policy propagates globally via supply chains, with the carbon-intensive sectors experiencing the greatest carbon emission shocks. We further reveal that China's current stimulus package in 2021-2025 is consistent with China's emission intensity-reduction goals for 2025, but further efforts are required to meet China's carbon emissions-peaking target in 2030 and Cancun 2°C goal. Short-term changes in carbon emissions resulting from lockdowns and initial fiscal stimuli in "economic rescue" period have minor long-term effects, whereas the transitional direction of future fiscal stimulus exerts more predominant impact on long-term carbon emissions. The efficiency improvement effects are more important than the sectoral structure effects of the fiscal stimulus in achieving greener economic growth. [Abstract copyright: © 2022 The Author(s).

Carbon emission imbalances and the structural paths of Chinese regions

As the Chinese regions become more and more connected to each other and foreign countries, this study aims to address carbon imbalance and outsourcing issues in China. Using a production-based carbon emission inventory and a China-global multi-regional input-output model, this study estimates the consumption-based carbon emissions in 30 Chinese regions in 2007 and 2010. Our results reveal that the carbon imbalances of most Chinese provinces and cities have decreased between 2007 and 2010, but disparities in the regional per capita carbon footprint have widened. Our Structural Path Analysis (SPA) results shows that most Chinese regions have higher ratios of both imported (to consumption-based) and exported (to production-based) carbon emissions in further upstream supplier tiers than that of direct imports and exports in the first tier, thus it's vital to trace emissions in the upstream supply chain to understand emission outsourcing. Our result from four case study provinces suggests that Beijing should import more electricity products from nearby Hebei and Shandong rather than Inner Mongolia to lower its consumption-based carbon emissions given the smaller emission coefficients of their electricity production

In vitro inhibition of proliferation, migration and epithelial-mesenchymal transition of human lens epithelial cells by fasudil

AIM: To study the potential role of fasudil as a treatment for posterior capsular opacification (PCO) of the human crystalline lens. METHODS: Human lens epithelial cells (HLECs; line SRA01/04) was exposed to transforming growth factor-β2 (TGF-β2) to induce the process of epithelial-mesenchymal transition (EMT). Fasudil was applied to the cell samples. Its effect on overall HLECs proliferation and migration was studied, as was its influence on EMT induction by TGF-β2 using cell migration assay, MTT colorimetric assay and Western blot assay. RESULTS: Fasudil inhibited the proliferation of SRA01/04. Its effect was time- and concentration-dependent. The migration of SRA01/04 cells was significantly reduced 24-72h after fasudil treatment, and the half maximal inhibitory concentration (IC50) was 22.37 μmol/mL at 72h. Reversal of the elongated, fibroblast-like shape changes induced by TGF-β2 in SRA01/04 cells was observed. Fasudil up-regulated the expression of Connexin43 protein and down-regulated the expression of α-SMA protein compared with the cells treated with TGF-β2. Furthermore, when exposed to fasudil, the phosphorylation of Rho-associated protein kinase (Rock) and myosin light chain (MLC) could not be activated in the cell preparations. CONCLUSION: Fasudil suppresses the proliferation and migration of SRA01/04 cells, and inhibits the process of EMT induced by TGF-β2. These results suggest that fasudil may serve as a therapeutic agent for PCO

Phase-Matching Quantum Key Distribution without Intensity Modulation

Quantum key distribution provides a promising solution for sharing secure keys between two distant parties with unconditional security. Nevertheless, quantum key distribution is still severely threatened by the imperfections of devices. In particular, the classical pulse correlation threatens security when sending decoy states. To address this problem and simplify experimental requirements, we propose a phase-matching quantum key distribution protocol without intensity modulation. Instead of using decoy states, we propose a novel method to estimate the theoretical upper bound on the phase error rate contributed by even-photon-number components. Simulation results show that the transmission distance of our protocol could reach 305 km in telecommunication fiber. Furthermore, we perform a proof-of-principle experiment to demonstrate the feasibility of our protocol, and the key rate reaches 22.5 bps under a 45 dB channel loss. Addressing the security loophole of pulse intensity correlation and replacing continuous random phase with 6 or 8 slices random phase, our protocol provides a promising solution for constructing quantum networks.Comment: Comments are welcome! 12 pages, 6 figure

Multiaxial fatigue life prediction using an improved Smith‐Watson‐Topper model

AbstractIn this paper, the SWT model was improved by incorporating the Walker equation into the strain–life curve. The established model takes into account the material's sensitivity to mean stress by introducing the Walker exponent, w. Under uniaxial loading condition, the proposed model can reduce to the SWT model, Manson‐Coffin equation, and Walker model for w values of 0.5, 1, and 0, respectively. Under multiaxial symmetric loading, when w = 0.5, the proposed model can be simplified as another SWT correction model (CXH) proposed by Chen et al. The prediction accuracy of the established model was validated using about 200 data points collected from literature. These data points were obtained from tests conducted on eight different kinds of metals under various multiaxial loading paths. The verification results indicate that 96.8% and 97.9% of the data points fall within the factor‐of‐three boundary for the loading paths without and with mean stresses, respectively.</jats:p

Influence of Disturbance on Soil Respiration in Biologically Crusted Soil during the Dry Season

Soil respiration (Rs) is a major pathway for carbon cycling and is a complex process involving abiotic and biotic factors. Biological soil crusts (BSCs) are a key biotic component of desert ecosystems worldwide. In desert ecosystems, soils are protected from surface disturbance by BSCs, but it is unknown whether Rs is affected by disturbance of this crust layer. We measured Rs in three types of disturbed and undisturbed crusted soils (algae, lichen, and moss), as well as bare land from April to August, 2010, in Mu Us desert, northwest China. Rs was similar among undisturbed soils but increased significantly in disturbed moss and algae crusted soils. The variation of Rs in undisturbed and disturbed soil was related to soil bulk density. Disturbance also led to changes in soil organic carbon and fine particles contents, including declines of 60–70% in surface soil C and N, relative to predisturbance values. Once BSCs were disturbed, Q10 increased. Our findings indicate that a loss of BSCs cover will lead to greater soil C loss through respiration. Given these results, understanding the disturbance sensitivity impact on Rs could be helpful to modify soil management practices which promote carbon sequestration

Catalytically efficient Ni-NiOₓ-Y₂O₃ interface for medium temperature water-gas shift reaction

The metal-support interfaces between metals and oxide supports have long been studied in catalytic applications, thanks to their significance in structural stability and efficient catalytic activity. The metal-rare earth oxide interface is particularly interesting because these early transition cations have high electrophilicity, and therefore good binding strength with Lewis basic molecules, such as H2O. Based on this feature, here we design a highly efficient composite Ni-Y2O3 catalyst, which forms abundant active Ni-NiOx-Y2O3 interfaces under the water-gas shift (WGS) reaction condition, achieving 140.6 μmolCO gcat-1 s-1 rate at 300 °C, which is the highest activity for Ni-based catalysts. A combination of theory and ex/in situ experimental study suggests that Y2O3 helps H2O dissociation at the Ni-NiOx-Y2O3 interfaces, promoting this rate limiting step in the WGS reaction. Construction of such new interfacial structure for molecules activation holds great promise in many catalytic systems