Electrochemically Switchable Ring-Opening Polymerization of Lactide and Cyclohexene Oxide

An electrochemical method was developed for the redox switchable polymerization of lactide and cyclohexene oxide. Using a lithium reversible sacrificial electrode and a high surface area carbon working electrode, efficient transformation between formally iron­(II) and iron­(III) oxidation states of a bis­(imino)­pyridine iron alkoxide complex was possible, which led to the ability to activate the complex for ring opening polymerization reactions. In addition to serving as a redox trigger, an electrochemical toggle switch was developed in which the chemoselectivity for lactide and epoxide polymerization was altered <i>in situ</i>. These findings led to the synthesis of poly­(lactic acid-<i>b</i>-cyclohexene oxide) block copolymers in which the sequence of monomers incorporated is controlled by the electrical potential applied

Functionalizing Titanium Disilicide Nanonets with Cobalt Oxide and Palladium for Stable Li Oxygen Battery Operations

Li oxygen (Li–O₂) batteries promise high energy densities but suffer from challenges such as poor cycling lifetime and low round-trip efficiencies. Recently, the instability of carbon cathode support has been recognized to contribute significantly to the problems faced by Li–O₂ batteries. One strategy to address the challenge is to replace carbon materials with carbon-free ones. Here, we present titanium silicide nanonets (TiSi₂) as such a new material platform for this purpose. Because TiSi₂ exhibits no oxygen reduction reaction (ORR) or oxygen evolution reaction (OER) activities, catalysts are required to promote discharge and recharge reactions at reduced overpotentials. Pd nanoparticles grown by atomic layer deposition (ALD) were observed to provide the bifunctionalities of ORR and OER. Their adhesion to TiSi₂ nanonets, however, was found to be poor, leading to drastic performance decay due to Pd detachments and aggregation. The problem was solved by adding another layer of Co₃O₄, also prepared by ALD. Together, the Pd/Co₃O₄/TiSi₂ combination affords the desired functionalities and stability. Li–O₂ test cells that lasted more than 126 cycles were achieved. The reversible formation and decomposition of Li₂O₂ was verified by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), ferrocenium back-titration, and gas-chromatography and mass spectrometry (GC-MS). Our results provide a new material platform for detailed studies of Li–O₂ operations for better understanding of the chemistries involved, which is expected to help pave the way toward practical Li–O₂ battery realizations

Supplementary Figures from Reliability modelling and analysis of a multi-state element based on a dynamic Bayesian network

This paper presents a quantitative reliability modelling and analysis method for multi-state elements based on a combination of the Markov process and a dynamic Bayesian network (DBN), taking perfect repair, imperfect repair and condition-based maintenance (CBM) into consideration. The Markov models of elements without repair and under CBM are established, and an absorbing set is introduced to determine the reliability of the repairable element. According to the state-transition relations between the states determined by the Markov process, a DBN model is built. In addition, its parameters for series and parallel systems, namely, conditional probability tables, can be calculated by referring to the conditional degradation probabilities. Finally, the power of a control unit in a failure model is used as an example. A dynamic fault tree (DFT) is translated into a Bayesian network model, and subsequently extended to a DBN. The results show the state probabilities of an element and the system without repair, with perfect and imperfect repair, and under CBM, with an absorbing set plotted by differential equations and verified. Through referring forward, the reliability value of the control unit is determined in different kinds of modes. Finally, weak nodes are noted in the control unit

Raw data of manuscript RSOS-171438

Raw data of manuscript RSOS-17143

The effect of attributional style on decision making.

<p>Scatter plot of the internal attributional style and the (A) overall bet size, (B) behavioral modulation of agency on bet size, (C) behavioral modulation of agency and outcome on bet size, and (D) neural modulation of agency and outcome on rACC activation. Negative correlation between neural modulation and internality in the rACC was overlaid on an axial slice of the group mean structural image. For display purposes, the activation map was shown at (Z>2.3). Please note that the scatter plot in panel D is only used to check possible outliers. The correlation coefficient should be treated cautiously due to the double-dipping issue. SW: subject win; SL: subject loss; CW: computer win; CL: computer loss.</p

The effect of agency and outcome on bet-related neural activations.

<p>Significant agency by outcome interactions in the medial and lateral prefrontal cortex are overlaid on the (A) axial and (B) sagittal slices of the group mean structural images. All activations were thresholded by using cluster detection statistics, with a height threshold of z>2.3 and a cluster probability of P<0.05, corrected for whole-brain multiple comparisons. The top right panel shows the enlarged view of the medial prefrontal cortex cluster, which was further divided into three, i.e., posterior (y = 26), middle (y = 40) and anterior (y = 54) ROIs to examine the possible functional dissociations. To further probe the interactions, the middle and bottom panel show the plots of percentage signal change in (C) the left IFG, (D) the posterior, (E) middle, and (F) anterior rACC, as a function of agency, outcome and streak length. Error bars denote within-subject error. SW: short-win; SL: short-loss; LW: long-win; LL: long-loss.</p

Schema of the card guessing game and experimental design.

<p>Each trial consisted of three stages: Bet, Choice and Feedback. During the Bet stage, two folded cards were shown on each side of the screen with one as the winning card, and subjects were asked to place their bet ($1,$2, $4 or$8). After a delay (jittered, mean 2s), the Choice stage started. Under the <i>Subject guess</i> (SG) condition, subjects were asked to guess which side their winning card was on. Under the <i>Computer guess</i> (CG) condition, the computer made the choice and subjects were asked to simply confirm the computer’s choice. Subjects were told explicitly in advance that the computer made the choice <i>randomly.</i> After another delay (jitter, mean 2s), the gamble was revealed and the outcome was displayed for 2 seconds. The next trial started after a delay (jittered, mean 2s). Not shown here, the choices of cards from the last five trials were shown at the top-middle of the screen.</p

Behavioral results.

<p>The averaged bet size was plotted as a function of previous outcome (win vs. loss) and streak length (1 to 5), separately for the CG (A) and SG (B) conditions. The same result was plotted again by separating the streak into short (1) and long (> = 2) streaks, which clearly showed the outcome by agency interaction in the long streak (D), but not the short streak (C) condition. E & F: Reaction time as a function of previous outcome and streak length (short vs. long). (G) The correlation of the gambler’s fallacy effect (as measured by the difference between bet size after loss(es) than after win(s)) between the CG and SG conditions. (H) The switch pattern of subjects’ choices under the SG condition. The small bar on the top left of each plot indicates the within-subject error (w.s.e).</p

Cross-subject correlation results.

<p>(A) The rACC that showed negative correlation between bet size changes and neural activation change as a function of prior outcome was overlaid on an axial slice of the group mean structural image. For display purposes, the activation map was shown at Z>2.3. (B) Scatter plot of the correlation. Please note the scatter plot is only used to check possible outliers. The correlation coefficient should be treated cautiously due to the double-dipping issue.</p

Descriptive statistics and gender differences in demographical, behavioral, and brain measures.

<p>Descriptive statistics and gender differences in demographical, behavioral, and brain measures.</p