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Special geometric features and complex working environments render the internal defects of small-diameter thick-walled steel pipes "easy to expand, difficult to detect". In this paper, a magnetic permeability perturbation testing (MPPT) method is proposed to assess the internal axial cracks of small-diameter thick-walled steel pipes. The mechanism of the MPPT method and its corresponding probe and magnetizer are introduced, and its feasibility is verified through a series of simulations and experiments. Experiments conducted using different sizes of small-diameter thick-walled pipes show that this method offers good performance with respect to the detection of internal axial cracks. Additionally, both diameter and wall thickness significantly affect the MPPT signal. To a certain extent, a greater wall thickness or a smaller diameter brings about a weaker signal. This method does not benefit from the lift-off effect, nor is it limited by the skin effect, which has great practical value as a supplement to the evaluation of thick-walled steel pipes. [ABSTRACT FROM AUTHOR]

Extracellular DNA (eDNA) is a critical component in the extracellular matrix (ECM) of bacterial biofilms, while little is known about the mechanisms underlying how eDNA integrates into the ECM through potential macromolecular interactions. Myxococcus xanthus biofilm was employed as a suitable model for the investigation due to the co-distribution of eDNA and exopolysaccharides (EPS) owing to their direct interactions in the ECM. DNA is able to combine with M. xanthus EPS to form a macromolecular conjugate, which is dominated by the electrostatic forces participating in the polymer-polymer interactions. Without intercalation binding, DNA-EPS interactions exhibit a certain degree of reversibility. Acting as a strong extracellular framework during biofilm formation process, the eDNA-EPS complex not only facilitates the initial cell adhesion and subsequent establishment of ECM architecture, but also renders cells within biofilms stress resistances that are relevant to the survival of M. xanthus in some hostile environments. Furthermore, the EPS protects the conjugated DNA from the degradation by nucleic acid hydrolases, which leads to the continuous and stable existence of eDNA in the native ECM of M. xanthus biofilms. These results will shed light on developing prevention and treatment strategies against biofilm-related risks. [ABSTRACT FROM AUTHOR]

This paper is intended for exploring the multifractal features of tanker freight rate market volatility with the common external factor of crude oil price by both the multifractal cross-correlation analysis method (MF-CCA) and the multifractal detrended partial cross-correlation analysis method (MF-DPXA) with consideration of finite size effect. The multifractal spectrums of original, random and surrogate time series are employed to separate the three components of multifractality, and to uncover the influence of financial crisis and oil price on volatility and cross-correlated fluctuations of the tanker freight rates. After the financial crisis in terms of the generalized Hurst exponent, stronger non-linear characteristic and noticeable anti-persistent characteristic in cross correlations between freight rates are supported by the MF-DPXA analysis. Meanwhile, stronger multifractality is indicated by the MF-CCA analysis. These results deepen the understanding of multifractality in tanker freight rate market, and provide investors, shipping related operators or even market players with insight to adjust their marketing strategies. [ABSTRACT FROM AUTHOR]

This work demonstrates an efficient way to prepare chiral propargylic alcohols by asymmetric addition of terminal Zn-acetylide to aldehydes catalyzed by bifunctional zinc-based complexes. The corresponding products with moderate to good yields and enantioselectivities were obtained in the absence of moisture-sensitive Ti(O i Pr)4. [ABSTRACT FROM AUTHOR]

The innovation behavior (IB) of followers is vital for individuals and organizations. It is not only an important part of individual performance but also an essential foundation of organizational innovation. In general, understanding the formation mechanism of followers' IB could enhance organizational innovation performance and sustainable competitiveness. The innovation of this study includes the following points. First, in the previous research on the antecedent variables of the IB of followers, the key factor of implicit follow cognitive difference (IFCD) was not examined. We add this key factor to the independent variables of our formation mechanism. Second, in the relationship between IFCD and followers' IB, we investigate the mediating role of psychological empowerment (PE) and the moderating role of person-organization Fit (P-O Fit), further shown as a mediation model with moderating variables. Third, this study adopts a longitudinal research design, and the data were obtained from 1:1 matched leaders and their followers of large and medium-sized enterprises in China. To avoid deviation in the homologous method, this study gathers data at three-month intervals to ensure that leadership's influence on followers is effective. In this study, Amos 24.0 and SPSS 24.0 are used for empirical research. The results show IFCD has a negative effect on the IB of followers; PE has a partial mediating effect on the relationship between IFCD and IB of followers; P-O Fit plays a positive regulatory role in the relationship between IFCD and PE, and P-O Fit moderates the mediating effect of PE on the relationship between IFCD and IB. Based on our empirical research, we put forward some feasible suggestions for company managers to increase sustainability in market competition by promoting the formation of the IB of followers. [ABSTRACT FROM AUTHOR]

The title reaction represents a practical and low-cost way to prepare arylalkynes. [ABSTRACT FROM AUTHOR]

Abstract: Four tridentate [C,N,S] thiosemicarbazone Pd(II) complexes were applied as catalyst precursors for the Suzuki–Miyaura coupling of a variety of aryl halides and aryl boronic acids. After screening various catalytic conditions, it was found that one dinuclear complex IV containing the bis(diphenylphosphino) ferrocene spacer was able to efficiently catalyze these reactions with yields up to 99% irrespective of the type of aryl substituent on the substrate. [Copyright &y& Elsevier]

Analysis of crude oil price and tanker freight rate volatility attract more attention as the mechanism is not only the basis of industrialization but also a vital role in economics, especially after the year 2008 when financial crisis notably blew the maritime transportation. In this paper, we studied the cross-correlations between the West Texas International crude oil (WTI) and Baltic Exchange Dirty Tanker Index (BDTI) employing the Multifractal Detrended Cross-Correlation Analysis (MF-DCCA). Empirical results show that the degree of short-term cross-correlation is higher than that in the long term and that the strength of multifractality after financial crisis is larger than that before. Moreover, the components of multifractal spectrum are quantified with the finite-size effect taken into consideration and an improved method in terms of constructing the surrogated time series provided. Numerical results show that the multifractality is generated mostly from the nonlinear and the fat-tailed probability distribution (PDF) part. Also, it is apparent that the PDF part changes a lot after the financial crisis. The research is contributory to risk management by providing various instructions for participants in shipping markets. Our main contribution is that we investigated both the multifractal features and the origin of multifractality and provided confirming evidence of multifractality through numerical results while applying quantitative analysis based on MF-DCCA; furthermore, the research is contributory to risk management since it provides instructions in both economic market and stock market simultaneously. However, constructing the surrogated series in order to obtain consistence seems less convincing which requires further discussion and attempts. [ABSTRACT FROM AUTHOR]

It is widely acknowledged that emerging stock markets and mature stock markets differ in many respects, while research on emerging markets is rather insufficient compared to well-studied mature markets. In this paper, we investigate the unique network properties and market pattern of the emerging Chinese stock market of crude oil related companies with the implementation of minimum spanning trees(MST) and hierarchical trees(HT). For a robust quantification of cross-correlation between stocks, detrended cross-correlation coefficient (DCCA coefficient) and partial cross-correlation coefficient (DPXA coefficient) are applied to reveal the overall cross-correlation and identify the common external factor on price fluctuations respectively. The paper depicts the dynamic evolution of Chinese stock market of crude oil related companies, showing the variation of structural density and stability under different time scales and market environments. The establishment of correlation-based networks provides a more pertinent explanation for the unusual market structure and conduct of the emerging Chinese stock market, contributing to both portfolio decisions and risk resistance. • Network properties and market patterns of the emerging Chinese stock market of crude oil related companies are explored by MST and HT. • DCCA coefficient and DPXA coefficient are applied respectively. • Small-volume stocks capture hub positions more frequently in both upturn and recession periods. [ABSTRACT FROM AUTHOR]