Engineering Magnetic Hybridization at Organic–Ferromagnetic Interfaces by C₆₀-Adsorption-Induced Fe(001) Surface Reconstruction

Large magnetoresistance has been reported for C₆₀-based vertical spin valves. But for the underlying organic–ferromagnetic interfacial atomistic structures, both experimental and theoretical works have assumed unreconstructed atomic structures for the <i>magnetic</i> surfaces, although organic molecule (e.g., fullerene and thiolate) adsorption frequently induces <i>nonmagnetic</i> surfaces reconstruction. Here we report that C₆₀ adsorption can induce a prototype ferromagnetic surface, Fe(001), reconstruction, via thorough structural search from first-principles calculations. We propose that Fe(001) surface reconstruction should already occur under the reported annealing temperature in literature. Reconstruction solidifies C₆₀/Fe interface bonding and enhances C₆₀ spin-polarization. More importantly, only our reconstructed structure can explain the experimental observation of an inversion of C₆₀ spin-polarization around Fermi-level relative to that of Fe substrate, which is attributed to the C₆₀ lowest unoccupied molecular orbitals LUMO-derived states are shifted to Fermi level by charge transfer and to the strong coupling in the reconstructed structure. One could expect that surface reconstruction occur not only at the C₆₀/Fe­(001) interface, but also at interfaces of other molecule-magnetic metals. Hence our work offers a new pathway to interface engineering, that is, via surface reconstruction to manipulate spintronic properties and promote the field of interface-assisted spintronics

Quantifying the effect of investors’ attention on stock market

<div><p>The investors’ attention has been extensively used to predict the stock market. Different from existing proxies of the investors’ attention, such as the <i>Google trends</i>, <i>Baidu index</i> (<i>BI</i>), we argue the collective attention from the stock trading platforms could reflect the investors’ attention more closely. By calculated <i>the increments of</i> <i>the attention volume</i> <i>for each stock</i> (<i>IAVS</i>) from the stock trading platforms, we investigate the effect of investors’ attention measured by the <i>IAVS</i> on the movement of the stock market. The experimental results for <i>Chinese Securities Index 100</i> (CSI100) show that the <i>BI</i> is significantly correlated with the returns of CSI100 at 1% significance level only in 2014. However, it should be emphasized that the correlation of the new proposed measure, namely <i>IAVS</i>, is significantly at 1% significance level in 2014 and 2015. It shows that the effect of the measure <i>IAVS</i> on the movement of the stock market is more stable and significant than <i>BI</i>. This study yields important invest implications and better understanding of collective investors’ attention.</p></div

Illustration of the hypotheses structures presented in this paper.

<p>Illustration of the hypotheses structures presented in this paper.</p

The illustration of the correlation between the CSI100 returns and the investors’ attention measured by the <i>BI</i> and <i>IAVS</i> for the day.

<p>The subplots (a)-(c) show the time series of Z-score of the returns of CSI100, the <i>BI</i> and the measure <i>IAVS</i> respectively, from which one can find that the measure <i>IAVS</i> correlates with the returns of CSI100 more closely. The Z-score is calculated in the way <i>z</i> = (<i>x</i> − <i>μ</i>)/<i>σ</i>, where <i>x</i>, <i>μ</i> and <i>σ</i> denote the original, mean value and standard deviation. We only consider trading days of the stock market, so there is no data in weekends and holidays.</p

Palladium-Catalyzed Tandem Regioselective Oxidative Coupling from Indoles and Maleimides: One-Pot Synthesis of Indolopyrrolocarbazoles and Related Indolylmaleimides

An efficient Pd­(II)-catalyzed approach for the direct synthesis of indolo­[3,2-<i>a</i>]­pyrrolo­[3,4-<i>c</i>]­carbazole-6,8-diones has been developed from both free and protected (NH) indoles and maleimides via a regioselective tandem oxidative coupling reaction. The yields are moderate to excellent. In addition, 2-substituted indoles are suitable substrates in this protocol, leading to the formation of indolylmaleimides. The present methodology provides a concise route to highly functionalized indolopyrrolocarbazole derivatives

Description of variables.

<p>Description of variables.</p

Illustration of <i>investors’ attention of the stock market</i> on 2017-03-04.

<p>This figure gives an illustration of investors’ attention of stock market column on 2017-03-04. This figure is intercepted from the stock trading platform named Choice, available online at <a href="http://choice.eastmoney.com/" target="_blank">http://choice.eastmoney.com/</a>. As shown, it mentions the top stocks chosen by investors into their watch lists on this stock trading platform on 2017-03-04, the increments and the ranking trend of investors’ attention. In fact, we can get the increments and the ranking trend of investors’ attention of each stock in every trading day in mainland China by collaborating with the eastmoney.com. Please note that the data publishes at 0 o’clock at the same trading day on the stock trading platform.</p

Results of the regression modeling with CSI500.

<p>Results of the regression modeling with CSI500.</p

Results of the regression modeling with CSI100.

<p>Results of the regression modeling with CSI100.</p