MXene Clay (Ti2C)-Containing In Situ Polymerized Hollow Core–Shell Binder for Silicon-Based Anodes in Lithium-Ion Batteries

Silicon, an attractive anode material, suffers fast capacity fading due to the electrical isolation from massive volumetric expansion upon cycling. However, it holds a high theoretical capacity and low operation voltage in its practical application. In this study, a new water-based binder, MXene clay/hollow core–shell acrylate composite, was synthesized through an in situ emulsion polymerization technique to alleviate the fast capacity fading of the silicon anode efficiently. The efficient introduction of conductive MXene clay and the hollow core–shell structure, favorable to electron and ion transport in silicon-based electrodes, gives a novel conceptual design of the binder material. Such a strategy could alleviate electrical isolation after cycling and promises better electrochemical performance of the high-capacity anodes. The effect of the MXene introduction and hollow core–shell on the binder performance is thoroughly investigated using various characterization tools by comparison with no MXene-containing, core–shell acrylate, and commercial styrene–butadiene latex binders. Consequently, the silicon-based electrode containing the MXene clay/hollow core–shell acrylate binder exhibits a high capacity retention of 1351 mAh g–1 at 0.5C after 100 cycles and good rate capability of over 1100 mAh g–1 at 5C

Beijing Opera Percussion Instrument Dataset

<p>The Beijing Opera percussion instrument dataset is a collection of audio examples of individual strokes spanning the four percussion instrument classes used in Beijing Opera (Jingju, 京剧).</p> <p>Beijing Opera uses six main percussion instruments that can be grouped into four classes: </p> <ol> <li><strong>Bangu</strong> (Clapper-drum) consisting of Ban (the clapper, a wooden board-­shaped instrument) + danpigu (a wooden drum struck by two wooden sticks)</li> <li><strong>Naobo</strong> (Cymbals) consisting of two cymbal instruments Qibo+Danao</li> <li><strong>Daluo</strong>: Large gong</li> <li><strong>Xiaoluo</strong>: Small gong</li> </ol> <p><strong>Audio content</strong></p> <p>The dataset provides audio examples for each of these instrument classes.</p> <p>The audio examples were recorded under studio conditions by Mi Tian at the <a href="http://c4dm.eecs.qmul.ac.uk/">Centre for Digital Music</a>, Queen Mary University of London, UK in September 2013 using an AKG C414 microphone. The audio was sampled at 44.1 kHz and stored as 16 bit wav files. The instruments were played by Ying Wan of the London Jing Kun Opera Association. Unlike some instruments that can be tuned, these percussion instruments are made from metal casting. Thus, there can be subtle timbral differences even across different instruments of the same kind. For each of these instruments, we used 2-3 individual instruments to record the samples, hoping to achieve a better timbre coverage. Further, audio samples were recorded using different playing techniques for each instrument.</p> <p>The dataset can be used for training models for each percussion instrument class. </p> <p>Each audio file is named as, </p> <pre><code>_.wav</code></pre> <p>Please cite the referenced paper if you use this dataset in your work.</p> <p><strong>Contact</strong></p> <p>If you have any questions or comments about the dataset, please feel free to write to us: </p> <p>Mi Tian ( [email protected] ) or Ajay Srinivasamurthy ( [email protected])</p

The Cu-catalyzed asymmetric conjugate addition with chiral diphosphite ligands derived from D-(-)-tartaric acid

<p>A series of diphosphite ligands, which were derived from D-(-)-tartaric acid, have been synthesized and successfully applied in the Cu-catalyzed asymmetric conjugate addition of organozincs to enones. There was a synergic effect between the stereogenic centers of the D-(-)-tartaric acid skeleton and the axially H₈-binaphthyl moieties of ligand <b>2c</b>. And ligand <b>2c</b> shows a comparative catalytic performance to ligand 1-<i>N</i>-benzylpyrrolidine-3,4-bis[(<i>S</i>)-1,1′-H₈-binaphthyl-2,2′-diyl]phosphite-L-tartaric acid<b>1d</b> derived from L-(+)-tartaric acid. Therefore, for cyclic enones, both enantiomers of the addition products can be obtained in high enantioselectivity (<i>ee</i>s up to 96%) by simply selecting ligands <b>1d</b> or <b>2c</b> derived from D-(-)-tartaric acid or L-(+)-tartaric acid. Moreover, the sense of enantiodiscrimination of the products was mainly determined by the configuration of the binaphthyl phosphite moieties.</p

Fig 2 -

Guangxi Cd geochemical maps (a: CGB Ⅰ, b: CGB Ⅱ).</p

Toward Process-Resilient Lignin-Derived Activated Carbons for Hydrogen Storage Applications

Activated carbons are promising sorbents that have been heavily investigated for the physisorptive storage of hydrogen. The industrial process for production of activated carbons is finely tuned and requires a reliable and uniform feedstock. While the natural biopolymer lignin, a byproduct of several industries, has received increasing interest as a potentially sustainable and inexpensive activated carbon feedstock, the ratio of the three aromatic monomers (S, G, and H) in lignin can be heavily affected by the lignin source and growing conditions. The aromatic ratio is known to influence the thermal behavior of the polymer, which could be problematic for production of consistent activated carbons at scale. With the goal of improving the consistency of activated carbons produced from lignins derived from different feedstocks, here we present a route to limiting the influence of lignin feedstock on activated carbon porosity and performance, resulting in a carbonization process that is resilient to changes in lignin source. Two different types of organosolv lignin (representing high S-unit content and high G-unit content feedstocks) were investigated. Resulting activated carbons exhibited a high surface area (>1000 m2·g–1) with consistent adsorptive properties and reasonable hydrogen uptake of up to 1.8 wt % at 1 bar and −196 °C. These findings indicate that low-temperature carbonization conditions can be used to produce a consistent carbon material using organosolv lignins from any source, paving the way for more widespread use of lignin in large-scale carbon production

Characteristics of 6 randomized controlled trials included in analysis.

(K, keratometry; D, diopter; SE, spherical equivalent; epi-off, conventional CXL; epi-on, transepithelial CXL).</p

Fitting parameters of GTWR.

Fitting parameters of GTWR.</p

Atmospheric Deposition of Halogenated Flame Retardants at Urban, E-Waste, and Rural Locations in Southern China

Measurements of atmospheric deposition fluxes and temporal variation of halogenated flame retardants (HFRs) from 2007 to 2008 at urban, electronic waste (e-waste), and rural sites in southern China are presented. The deposition fluxes of total HFRs at the urban (99.3–1327 ng m–2 day–1) and e-waste (79.1–1200 ng m–2 day–1) sites were much higher than at the rural site (9.27–79.5 ng m–2 day–1), demonstrating that e-waste recycling and industrial activities in southern China are two important sources of HFRs in the environment. The urban deposition profile was dominated by current-use HFRs (decabrominated diphenyl ether and decabromodiphenyl ethane), whereas the profile at the e-waste site reflects the past when significant amounts of PBDEs and Dechlorane Plus were used. Source apportionment estimated by principal component analyses with multiple linear regression analysis showed that deposition HFRs at the rural site were primarily contributed by the urban and e-waste sources (45% and 38%, respectively) compared to the contribution from local emission (17%). Our results suggest that the HFRs that are readily present in gas or sorbed onto fine particle phases have enhanced potential for long-range atmospheric transport

Descriptive statistical analysis of Cd.

Descriptive statistical analysis of Cd.</p

Fig 1 -

Spatial-temporal distribution of driving factors (a: Zr; b: Temperature; c: Precipitation; d: pH; e: Corg (organic carbon); f: NDVI; g: Industrial pollutants; h: Domestic pollutants; i: Agricultural pollutants; j: Deposit density; Ⅰ for CGB Ⅰ; Ⅱ for CGB Ⅱ).</p