Enhanced ion-electron mixing interface for high energy solid-state lithium metal batteries.

Solid-state Li metal batteries (SSLMBs) are famous for superior security and excellent energy density. Nevertheless, the poor interfacial contact between solid lithium and electrode is one key problem in the development of SSLMBs, resulting in high impedance and growth of lithium dendrites along the grain boundaries. Herein, an innovative and accessible approach has been applied to SSLMBs, which introduces an ion-electron mixing (IEM) interface on the surface of Li1.3Al0.3Ti1.7(PO4)3 (LATP). The IEM interlayer generates LixSn/LiI of fast lithium-ion conductor through an in-situ reaction. The existence of LiI would promote the quick transmission of Li+ at the interface and inhibit the electronic conduction, thus restraining the growth of lithium dendrites. The batteries with IEM@LATP electrolyte could stably cycle more than 1000 h at high current density of 0.1 mA cm-2. Even increasing the current density to 3.0 mA cm-2, the batteries still could work normally. This novel and viable approach offers a robust basis for the practical application of SSLMBs and has some general applicability to other solid-state batteries.

A Low-Cost and Scalable Synthesis of a Cyclohexanone-Related Bifunctional Building Block.

A practical route to 2-(2-(2-methyl-1,3-dioxolan-2-yl)ethyl)cyclohexan-1-one was developed, featuring the use of inexpensive starting materials/reagents and readily attainable reaction conditions. The overall transformation was achieved in 53% yield with one chromatographic purification via NaOH-mediated aldol condensation, ethylene glycol protection of the ketone group in the presence of HC(OEt)3/concd HCl, saturation of the C=C bond and the benzene ring with Al-Ni alloy in aqueous KOH, and oxidation of the intermediate cyclohexanol with aqueous NaClO/TEMPO/KBr.

Two novel semiconducting B2 CO monolayers with high carrier mobilities.

The design of new two-dimensional (2D) materials with moderate band gaps and high carrier mobility is an important aspiration for materials innovation. Recent studies have shown that boron and oxygen atoms can be integrated into the graphene lattice to form a stable B-C-O monolayer structure. To search for the most energetically stable configuration for 2D B-C-O, here, we theoretically propose two new 2D B-C-O crystal structures with a stoichiometric ratio of 2:1:1, namely monolayer (1 L) C3v - and C2v -B2 CO. Two configurations have 0.09 and 0.03 eV/unit cell lower energies than the reported 1 L Cs -B2 CO configuration (Nanoscale 2016, 8, 8910). This result is further confirmed by particle swarm optimization (PSO) calculations. According to the chemical bonding analysis, 1 L C3v -B2 CO with a quasi-planar configuration has the lowest energy, which is consisted of three strong B'-O σ-bonds, three B″-C σ-bonds, and one B'-C σ-bond. As a result, 2D B2 CO has an ultra-high mechanical strength of ~366 J m-2 , comparable to graphene ~352 J m-2 . In addition, 1 L C3v -B2 CO is a semiconductor with an HSE06 bandgap of 2.57 eV, and it has a high electron mobility of up to ~150 cm2  v-1  s-1 . The high kinetic and thermodynamic stabilities of both 1 L C3v - and C2v -B2 CO were confirmed according to phonon dispersion and molecular dynamic simulation. Comparable to that of crystalline silicon, 1 L C3v -B2 CO also shows a high light absorption intensity in the 400-550 nm region. Therefore, 2D C3v -B2 CO will have promising applications in semiconductor devices and photodetectors.

Comparison of soil microbial community between reseeding grassland and natural grassland in Songnen Meadow.

Microorganisms have important ecological functions in ecosystems. Reseeding is considered as one of the main strategies for preventing grassland degradation in China. However, the response of soil microbial community and diversity to reseeding grassland (RG) and natural grassland (NG) remains unclear, especially in the Songnen Meadow. In this study, the soil microbial community compositions of two vegetation restoration types (RG vs NG) were analyzed using a high-throughput sequencing technique. A total of 23,142 microbial OTUs were detected, phylogenetically derived from 11 known bacterial phyla. Soil advantage categories included Proteobacteria, Acidobacteria, Actinobacteria, and Bacteroidetes, which together accounted for > 78% of the all phyla in vegetation restoration. The soil microbial diversity was higher in RG than in NG. Two types of vegetation restoration had significantly different characteristics of soil microbial community (P < 0.001). Based on a molecular ecological network analysis, we found that the network in RG had a longer average path distance and modularity than in NG network, making it more resilient to environment changes. Meanwhile, the results of the canonical correspondence analysis and molecular ecological network analysis showed that soil pH (6.34 ± 0.35 in RG and 7.26 ± 0.28 in NG) was the main factor affecting soil microbial community structure, followed by soil moisture (SM) in the Songnen meadow, China. Besides, soil microbial community characteristics can vary significantly in different vegetation restoration. Thus, we suggested that it was necessary and reasonable for this area to popularize reseeding grassland in the future.

Regio- and Stereoselective Addition of HO/OOH to Allylic Alcohols.

A range of allylic alcohols are shown to readily react with ethereal H2O2 in the presence of catalytic amounts of Na2MoO4-gly or MoO2(acac)2, affording the C═C trans hydroxylation-hydroperoxylation products in good yields with high regio- and stereoselectivity. Use of enantiomers of cyclic substrates resulted in corresponding enantiopure diol-tert-hydroperoxides. The possibility of further conversion of the diol-tert-hydroperoxides into triols or linear building blocks with an isolated tert-peroxy group containing a quaternary center is also exemplified.

Facile perhydrolysis of oxetanes catalyzed by molybdenum species.

Perhydrolysis of a range of tertiary oxetanes was achieved in synthetically useful yields under mild conditions. Different functional/protecting groups were tolerated. Similar ring-opening of secondary oxetanes, which had been unfeasible to date, was also realized with ease. With the aid of optically active substrates the perhydrolysis was shown to proceed with significant stereoselectivity.

A hydrogen peroxide based access to qinghaosu (artemisinin).

Attachment of H(2)O(2) onto the highly hindered quaternary C-12a in an advanced qinghaosu (artemisinin) precursor has been achieved through a facile perhydrolysis of a spiro epoxy ring with the aid of a previously unknown molybdenum species without involving any special equipment or complicated operations. The resultant ß-hydroxyhydroperoxide can be further elaborated into qinghaosu, illustrating an entry fundamentally different from the existing ones to this outstanding natural product of great importance in malaria chemotherapy.

[Near-infrared reflectance spectroscopy analytic models established for the crude protein and crude fiber of alfalfa property].

Near-infrared reflectance spectroscopy (NIRS) calibrations of crude protein and crude fiber in 152 alfalfa samples were developed by means of partial least-squares (PLS) regression. Different interval wavelengths of 1, 2 and 5 nm and two kinds of samples (crude and fine) were set to collect spectral data and establish calibration respectively. The accuracy and repeatability of calibrations were verified so as to compare superiority and inferiority. Results showed that the best validation result is the calibration by 2 nm interval wavelength and fine sample, and the correlation coefficients of calibration (R2) were 0.97 and 0.94 for crude protein and crude fiber, and the SECV of these parameters were 0.42 and 0.78 respectively. The coefficients of determination for validation (R2(val)) were 0.96 and 0.92, and the SEP of these parameters were 0.43 and 0.79. The experiment showed that it is feasible to evaluate the major quality traits of alfalfa by NIRS. All together, it provided a new model to verify the crude protein and fiber compositions of alfalfa.