Graphene supported Au-Pd bimetallic nanoparticles exhibit high catalytic activity in methanol selective oxidation, with a methanol conversion of 90.2% and selectivity of 100%, to methyl formate at 70 °C, owing to the synergism of Au and Pd particles as well as the strong interaction between graphene and Au-Pd nanoparticles.

No abstract

High Si/Al ratio HZSM-5 zeolite exhibits excellent catalytic performance in the synthesis of polyoxymethylene dimethyl ethers from dimethoxymethane and trioxymethylene.

To design highly efficient catalysts, new concepts for optimizing the metal-support interactions are desirable. Here we introduce a facile and general template approach assisted by atomic layer deposition (ALD), to fabricate a multiply confined Ni-based nanocatalyst. The Ni nanoparticles are not only confined in Al2 O3 nanotubes, but also embedded in the cavities of Al2 O3 interior wall. The cavities create more Ni-Al2 O3 interfacial sites, which facilitate hydrogenation reactions. The nanotubes inhibit the leaching and detachment of Ni nanoparticles. Compared with the Ni-based catalyst supported on the outer surface of Al2 O3 nanotubes, the multiply confined catalyst shows a striking improvement of catalytic activity and stability in hydrogenation reactions. Our ALD-assisted template method is general and can be extended for other multiply confined nanoreactors, which may have potential applications in many heterogeneous reactions.

No abstract

The effects of tillage and residue input amounts on soil phosphatase (alkaline phosphomonoesterase ALP, acid phosphomonoesterase ACP, phosphodiesterase PD, and inorganic pyrophosphatase IPP) activities and soil phosphorus (P) forms (total P, organic P, and available P) were evaluated using soils collected from a three-year experiment. The results showed that no-till increased soil total and organic P, but not available P as compared to conventional tillage treatments. Total P was increased as inputs of crop residue increased for no-till treatment. There were higher ALP and IPP activities in no-till treatments, while higher PD activity was found in tillage treatments and tillage had no significant effect on ACP activity. Overall phosphatase activities increased with an increase of crop residue amounts. Soil total P was correlated negatively with PD activity and positively with other phosphatase activities. Organic P had a positive correlation with ACP activity, but a negative correlation with PD activity. Available P had no significant correlation with phosphatase activities. Our data suggests that no-till and residue input could increase soil P contents and enhance the activities of phosphatase.

No abstract

Three new napyradiomycins (1–3) were isolated from the culture broth of a marine-derived actinomycete strain SCSIO 10428, together with six known related analogues napyradiomycin A1 (4), 18-oxonapyradiomycin A1 (5), napyradiomycin B1 (6), napyradiomycin B3 (7), naphthomevalin (8), and napyradiomycin SR (9). The strain SCSIO 10428 was identified as a Streptomyces species by the sequence analysis of its 16S rRNA gene. The structures of new compounds 1–3, designated 4-dehydro-4a-dechloronapyradiomycin A1 (1), 3-dechloro-3-bromonapyradiomycin A1 (2), and 3-chloro-6,8-dihydroxy-8-α-lapachone (3), respectively, were elucidated by comparing their 1D and 2D NMR spectroscopic data with known congeners. None of the napyradiomycins 1–9 showed antioxidative activities. Napyradiomycins 1–8 displayed antibacterial activities against three Gram-positive bacteria Staphylococcus and Bacillus strains with MIC values ranging from 0.25 to 32 μg mL−1, with the exception that compound 3 had a MIC value of above 128 μg mL−1 against Staphylococcus aureus ATCC 29213. Napyradiomycins 2, 4, 6, and 7 exhibited moderate cytotoxicities against four human cancer cell lines SF-268, MCF-7, NCI-H460, and HepG-2 with IC50 values below 20 μM, while the IC50 values for other five napyradiomycins 1, 3, 5, 8 and 9 were above 20 μM.