Utilizing a Photocatalysis Process to Achieve a Cathode with Low Charging Overpotential and High Cycling Durability for a Li-O2 Battery.

The practical applications of non-aqueous lithium-oxygen batteries are impeded by large overpotentials and unsatisfactory cycling durability. Reported here is that commonly encountered fatal problems can be efficiently solved by using a carbon- and binder-free electrode of titanium coated with TiO2 nanotube arrays (TNAs) and gold nanoparticles (AuNPs). Ultraviolet irradiation of the TNAs generates positively charged holes, which efficiently decompose Li2 O2 and Li2 CO3 during recharging, thereby reducing the overpotential to one that is near the equilibrium potential for Li2 O2 formation. The AuNPs promote Li2 O2 formation, resulting in a large discharge capacity. The electrode exhibits excellent stability with about 100 % coulombic efficiency during continuous cycling of up to 200 cycles, which is due to the carbon- and binder-free composition. This work reveals a new strategy towards the development of highly efficient oxygen electrode materials for lithium-oxygen batteries.

Brønsted acid promoted benzylic C-H bond functionalization of azaarenes: nucleophilic addition to aldehydes.

A practical Brønsted acid promoted benzylic C-H functionalization of 2-methylazaarenes and nucleophilic addition to aldehydes was developed in good to excellent yields. A six-membered hydrogen-bonding transition state is proposed to be crucial for the reaction. Ready availability of the two starting materials, the use of acetic acid as the catalyst and the facile reaction conditions will guarantee this synthetic method attractive to the synthesis of bioactive pyridine and quinoline derivatives.

Evaluating the effects of different sowing dates and tillage methods on dry-land wheat grain dry matter accumulation based on the APSIM model.

Accurate simulation of dry matter accumulation in wheat grains can provide important technical support for regulating wheat production in hilly areas of Loess Plateau. Using the APSIM model, we analyzed dryland wheat grain dry matter accumulation and distribution using the meteorological data from 1971 to 2017 in Anding District, and the field test data from 2016 to 2017 in Anjiagou Village, Fengxiang Town, Anding District, Dingxi City, Gansu Province. Furthermore, the influence of sowing date and tillage method on dry matter accumulation of wheat grain was quantitatively analyzed on the basis of model validation. The results showed that the root mean square error (RMSE) between the simulated and measured values of grain dry matter was 57.5-143.1 kg·hm-2 and the normalized root mean square error (NRMSE) was 1.4%-9.9% under the three sowing dates and four tillage methods, respectively. The precision of the APSIM model was satisfactory. Under different sowing dates, the order for beneficial degree of tillage treatment to dry matter accumulation in wheat grains was no tillage with straw cover > conventional tillage with straw cover > no tillage > conventional tillage. The treatment of no tillage with straw covered was the most favora-ble to dry matter accumulation in wheat grains, with no significant difference between no tillage and conventional tillage treatments. Under different farming methods, early sowing was better than normal sowing and late sowing for the dry matter accumulation process of wheat. Late sowing had stronger impacts on dry matter accumulation, with the least ideal accumulation process.

Radical-Dual-Difunctionalization and Trifluoromethylative Decarboxylation of Two Different Alkenes.

From a single alkene to two different alkenes! A convenient Fe-catalyzed A-D-A-T-type radical-dual-difunctionalization and cross-coupling of two different alkenes to provide chain elongated and trifluoromethylated aromatic alkenes has been developed.

Four-Component Radical Dual Difunctionalization (RDD) of Two Different Alkenes with Aldehydes and tert-Butyl Hydroperoxide (TBHP): An Easy Access to ß,δ-Functionalized Ketones.

A convenient Fe-catalyzed four-component radical dual difunctionalization and ordered assembly of two alkenes with aromatic/aliphatic aldehydes and TBHP to provide chain elongated ß,δ-functionalized ketones via a one-pot procedure has been developed. Aldehydes were homolytically cleavaged to produce acyl radicals and subsequently allowed for the successive construction of C(sp2)-C(sp3), C(sp3)-C(sp3), and C(sp3)-O bonds via dual radical insertions and radical-radical coupling, following the intrinsic nucleo/electrophilic reactivity of both the radicals and alkenes.

Facile and scalable carbon- and binder-free electrode materials for ultra-stable and highly improved Li-O2 batteries.

A carbon- and binder-free Ti@Ru material is synthesized through a facile and controllable strategy. A Ti@Ru based Li-O2 battery can effectively avoid the subsidiary reactions, and can be reversibly and continuously cycled for more than 500 cycles with an efficiency ca. 100%, exhibiting an ultra-cycling stability.

A new cyclopeptide with antifungal activity from the co-culture broth of two marine mangrove fungi.

A new cyclic tetrapeptide, cyclo-(L-leucyl-trans-4-hydroxy-L-prolyl-D-leucyl-trans-4-hydroxy-L-proline) (1), was isolated from the co-culture broth of two mangrove fungi Phomopsis sp. K38 and Alternaria sp. E33. The structure of 1 was determined by analysis of spectroscopic data and Marfey's analytic method. Primary bioassay demonstrated that compound 1 exhibited moderate to high inhibitory activity against four crop-threatening fungi including Gaeumannomyces graminis, Rhizoctonia cerealis, Helminthosporium sativum and Fusarium graminearum as compared with triadimefon.