Transition-Metal-Free Aluminosilicate Small-Pore Zeolites Upgrade Methane to Light Olefins.

Upgrading methane to value-added chemicals is significant but still challenging. Well-designed catalysts are required to activate methane. Extensive efforts have been dedicated to the catalytic conversion of methane over transition-metal-containing catalysts.

Aluminum Distribution in Ferrierite Zeolites Influences the Performance of Methane Oxidation.

Transition-metal-free aluminosilicate FER-type zeolite has been demonstrated to effectively catalyze methane to methanol using NO as the oxidant with distorted tetra-coordinated aluminum (Al) and penta-coordinated aluminum (Al) as potential active sites. However, the specific effects of Al distribution on the active Al species have not been thoroughly investigated. Herein, aluminosilicate FER-type zeolites with controllable Al distribution were developed.

Aluminum Distribution on the Microporous and Hierarchical ZSM-5 Intracrystalline and Its Impact on the Catalytic Performance.

In our previous work, the control of aluminum distribution on microporous ZSM-5 with and without the addition of sodium (Na) was conducted. In the current research, adjustment of the aluminum distribution on hierarchical ZSM-5 synthesized using a surfactant as a mesoporogen has been carried out. The investigation of aluminum distribution was based on Al MAS NMR, constraint index (CI) value, and Co(II) ion-adsorbed UV-vis.

Revealing Active Sites and Reaction Pathways in Direct Oxidation of Methane over Fe-Containing CHA Zeolites Affected by the Al Arrangement.

Fe-containing zeolites are effective catalysts in converting the greenhouse gases CH and NO into valuable chemicals. However, the activities of Fe-containing zeolites in methane conversion and NO decomposition are frequently conflated, and the activities of different Fe species are still controversial. Herein, Fe-containing aluminosilicate CHA zeolites with Fe species at different spatial distances affected by the arrangement of framework Al atoms were synthesized in a one-pot manner in the presence or absence of Na.

Direct Oxidation of Methane to Methanol over Transition-Metal-Free Ferrierite Zeolite Catalysts.

Direct oxidation of methane to methanol was reported to be highly dependent on the transition- or noble-metal-loading catalysts in the past decades. Here, we show that the transition-metal-free aluminosilicate ferrierite (FER) zeolite effectively catalyzed methane and NO to methanol for the first time. The distorted tetracoordinated Al in the framework and pentacoordinated Al on the extra framework formed during calcination, activation, and reaction processes were confirmed as the potential active centers.

Understanding the effect of spatially separated Cu and acid sites in zeolite catalysts on oxidation of methane.

Unraveling the effect of spatially separated bifunctional sites on catalytic reactions is significant yet challenging. In this report, we investigate the role of spatial separation on the oxidation of methane in a series of Cu-exchanged aluminosilicate zeolites. Regulation of the bifunctional sites is done either through studying a physical mixture of Cu-exchanged zeolites and acidic zeolites or by systematically varying the Cu and acid density within a family of zeolite materials.

Modulation of Al Distribution in High-Silica ZSM-5 Zeolites for Enhancing Catalytic Performance.

The spatial distribution of framework Al (Al) has been one of the important factors that affect the catalytic properties of zeolites in diverse chemical reactions; however, the synthesis of high-silica zeolites with special Al distribution remains a challenge. In this study, we successfully synthesized high-silica ZSM-5 zeolites with a unique Al distribution by employing pentaerythritol (PET) as an additive in the presence of a few tetrapropylammonium hydroxide (TPAOH). The results demonstrated that the introduction of PET led to a higher proportion of Al atoms located at the sinusoidal and/or straight channels.

Fabrication of 2D/2D BiOBr/g-CN with efficient photocatalytic activity and clarification of its mechanism.

Precise regulation of photoexcited charge carriers for separation and transportation is a core requirement for practical application in the photocatalysis field. Herein, a 2D/2D BiOBr/g-CN heterojunction is prepared by a self-assembly method and exhibits enhanced and stable activity for photocatalytic degradation of bisphenol A (BPA) and norfloxacin (NFA) under visible light. Compared to pure g-CN, the kinetic constants of BPA and NFA degradation over BiOBr/g-CN are enhanced by about 14.

Stable Tunable Luminescence of Hetero-valent Eu Ion Activated BaInTaO Phosphors Synthesized by Defect-Induced Self-Reduction in the Molten-Salt Method.

Functional materials with stable and adjustable luminescence have recently become a research hotspot for their broad application prospects. Tunable luminescence can be realized by the doping of hetero-valent europium ions. High-temperature hydrogen atmosphere reduction is required in the traditional preparation of Eu-doped phosphors.

Molecular identification of Theileria equi, Babesia caballi, and Rickettsia in adult ticks from North of Xinjiang, China.

Background: Ticks in Xinjiang distribute widely and account for one third of China. Ticks can carry and transmit bacteria, virus, and parasite. However, the research of tick-borne pathogens in Xinjiang is rather little.

Identifying age-specific gene signatures of the human cerebral cortex with joint analysis of transcriptomes and functional connectomes.

The human cerebral cortex undergoes profound structural and functional dynamic variations across the lifespan, whereas the underlying molecular mechanisms remain unclear. Here, with a novel method transcriptome-connectome correlation analysis (TCA), which integrates the brain functional magnetic resonance images and region-specific transcriptomes, we identify age-specific cortex (ASC) gene signatures for adolescence, early adulthood and late adulthood. The ASC gene signatures are significantly correlated with the cortical thickness (P-value <2.

HIV-1 genotype diversity and distribution characteristics among heterosexually transmitted population in Jiangsu province, China.

Background: Heterosexual transmission has contributed greatly to the current HIV-1 epidemic in China. However, the HIV-1 genetic characteristics in the heterosexually transmitted population in Jiangsu province remained unclear.

Methods: A molecular epidemiological investigation on heterosexual transmission of HIV-1 was conducted across Jiangsu province.

OsNF-YC10, a seed preferentially expressed gene regulates grain width by affecting cell proliferation in rice.

Grain size and shape are important factors in determining the grain yield. In this study, OsNF-YC10, a member of the NF-Y transcription factor family encoding a putative histone transcription factor, was cloned and characterized. qRT-PCR and mRNA in situ hybridization analysis revealed that OsNF-YC10 was highly expressed in endosperm and spikelet hull at late developmental stages.

Selective oxidation of methane to methanol with HO over an Fe-MFI zeolite catalyst using sulfolane solvent.

The effect of reaction conditions for direct oxidation of methane to methanol over Fe-MFI zeolite with H2O2 has been investigated. Sulfolane has been proved to be an efficient solvent for liquid-phase methane oxidation. A sulfolane/water mixture with an appropriate proportion led to an extremely high methanol production with a high selectivity.

Geographic Distribution and Temporal Trends of HIV-1 Subtypes through Heterosexual Transmission in China: A Systematic Review and Meta-Analysis.

: Heterosexual transmission (HST) has become the current predominant transmission pathways of the HIV-1 epidemic in China. The aim of this study was to explore the geographic and dynamic change of HIV-1 subtypes through HST in China from published studies. : Several electronic databases were searched to identify the studies, and the overall prevalence of HIV-1 subtypes was estimated by a meta-analysis method.

GEAR: A database of Genomic Elements Associated with drug Resistance.

Drug resistance is becoming a serious problem that leads to the failure of standard treatments, which is generally developed because of genetic mutations of certain molecules. Here, we present GEAR (A database of Genomic Elements Associated with drug Resistance) that aims to provide comprehensive information about genomic elements (including genes, single-nucleotide polymorphisms and microRNAs) that are responsible for drug resistance. Right now, GEAR contains 1631 associations between 201 human drugs and 758 genes, 106 associations between 29 human drugs and 66 miRNAs, and 44 associations between 17 human drugs and 22 SNPs.

PPIM: A Protein-Protein Interaction Database for Maize.

Maize (Zea mays) is one of the most important crops worldwide. To understand the biological processes underlying various traits of the crop (e.g.

Response mechanism of the phase transitions of poly(n-isopropylacrylamide-co-benzo-18-crown-6-acrylamide) using infrared spectroscopy.

The thermal and ionic effects on the phase transitions of poly(N-isopropylacrylamide) (PNIPAAm) and its copolymer with benzo-18-crown-6-acrylamide, poly(N-isopropylacrylamide-co-benzo-18-crown-6-acrylamide) (PNIPAAm-co-BCAm), were investigated using infrared (IR) spectral variations of methyl (CH3), C=O, and amine (NH) groups. Subsequently, perturbation correlation moving-window two-dimensional correlation infrared spectroscopy (PCMW 2D-IR) was applied to clarify the differences in the phase-transition mechanisms of the polymers. The dominant influence on the phase-transition mechanism of PNIPAAm is whether the anion is evenly distributed in the bulk solution.

Room-temperature synthesis of BiOBr sub-microflowers and their photocatalytic properties.

Flower-like BiOBr sub-microstructures about 500 nm in diameter have been synthesized in the presence of tetraethylammonium bromide (TEAB) via a solution route at room temperature. SEM observation shows that these sub-microflowers are composed of nanoflakes with the thickness of 20 nm. The photocatalytic activities of flower-like BiOBr were evaluated by the degradation of methyl orange (MO) and phenol under visible-light and UV-light irradiation, which presented the efficiencies up to 97% within 1.