[Temporal and Spatial Variation in Odor Pollution and Membrane Barrier Effect in Municipal Solid Waste Landfill].

In order to explore the source characteristics as well as the temporal and spatial variations in odor pollution in municipal waste landfills, gas samples were collected from a landfill in an eastern coastal area of China throughout winter and summer. The total concentration of malodorous substances reached 60000 μg·m. There were more types of odor pollutants detected in summer than in winter, the average concentration was 30-300 times higher than that in winter, and the concentration of sulfur compounds increased by 4.

Soluble and Perfluorinated Polyelectrolyte for Safe and High-Performance Li-O Batteries.

The severe performance degradation of high-capacity Li-O batteries induced by Li dendrite growth and concentration polarization from the low Li transfer number of conventional electrolytes hinder their practical applications. Herein, lithiated Nafion (LN) with the sulfonic group immobilized on the perfluorinated backbone has been designed as a soluble lithium salt for preparing a less flammable polyelectrolyte solution, which not only simultaneously achieves a high Li transfer number (0.84) and conductivity (2.

Nonlocal Electronic Correlations in the Cohesive Properties of High-Pressure Hydrogen Solids.

High-pressure hydrogen exhibits remarkable phenomena including the insulator-to-metal (IM) transition; however, a complete resolution of its phase diagram is still an elusive goal despite many efforts and much controversy. Theoretical modeling is typically based on density functional theory (DFT) with a mean-field description of electronic correlations, which is known to be rather limited in describing IM transitions. Herein, we show that nonlocal electron correlations play a central role in the relative stability of solid hydrogen phases, and that DFT-correcting for these correlations by the many-body dispersion (MBD) model reaches the accuracy of quantum Monte Carlo (QMC) simulations and predicts the same 2/-24 → -12 → Cs(IV) IM transition.

Tuning the catalytic activity of a single Mo atom supported on graphene for nitrogen reduction via Se atom doping.

Electrochemical nitrogen (N2) fixation as an effective method has realized the sustainable production of ammonia where efficient electrocatalysts for converting N2 into NH3 at room temperature have become a key scientific issue. Herein, we proposed that the catalytic activity of a single Mo atom supported on graphene (Mo/G) for the nitrogen reduction reaction (NRR) can be tuned by non-metal heteroatom (B, N, P, S, Se etc.) doping.

Long-Term Stability of Perovskite Solar Cells under Different Growth Conditions: A Defect-Controlled Water Diffusion Mechanism.

Understanding the water-infiltration process is crucial for improving the long-term stability of perovskite solar cells (PSCs). Although many attempts have been made in this regard, the role of growth condition in PSC synthesis, which has been observed experimentally to be essential for the stability of PSCs, remains elusive. Using first-principles tools, we demonstrate that the growth condition strongly controls the water-infiltration process of PSCs by dictating the formation of point defects on PSC surfaces.

An Integrated Design with new Metal-Functionalized Covalent Organic Frameworks for the Effective Electroreduction of CO.

One of the long-standing issues that prohibits large-scale CO reutilization is the low aqueous solubility of CO and the incurring inefficient mass transport of CO . Herein, we suggest a feasible way to promote the CO reutilization by integrating the storage and reduction, with a new covalent organic framework (COF) series constituted by cobalt-phthalocyanine and boronic acid linkers. We find that the porous structure of the cobalt COF is competitive in the CO storage and can sustain a high CO concentration around the reduction center, whereas the mass transport of CO as well as the efficiency of the CO reduction is significantly improved.

Geometric and electronic structure of multilayered graphene: synergy of the nondirective ripples and the number of layers.

According to the Mermin-Wagner theorem, ripple deformation is ubiquitous in a two-dimensional (2D) free-standing sheet, influencing the electronic properties. However, the synergistic effects of the unrestricted ripples and the number of layers have still been a topic of extensive debate. To address this issue, we employed density functional theory including many-body van der Waals (vdW) correction to investigate the effects of the nondirective ripples on the geometric and electronic structures of multilayered graphene.

[Research on quality standards of Aleuritopteris Herba].

This study aims to establish quality standards of Aleuritopteris Herba (AH), which could supply scientific evidence for the quality control of AH. The morphological and microscopic identification characters were reformulated. The tests of water content, total ash, acid-insoluble ash and ethanol-soluble extractives of AH were carried out according to the methods recorded in appendix of Chinese Pharmacopeia (2010 edition, volume 1).

Cobalt-porphine catalyzed CO electro-reduction: a novel protonation mechanism.

The urgent need for artificially fixing CO calls for catalysts of high efficiency. The transition metal functionalized porphyrin (TMP) is one of the most important types of organic catalysts for CO reduction. However, the catalytic mechanisms of TMP in CO reduction still remain controversial.

Determination of six polyether antibiotic residues in foods of animal origin by solid phase extraction combined with liquid chromatography-tandem mass spectrometry.

A new method using solid phase extraction (SPE) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed for the determination of six polyether antibiotics, including lasalocid, salinomycin, monensin, narasin, madubamycin and nigericin residues, in foods of animal origin. The samples were extracted with acetonitrile and purified by ENVI-Carb SPE columns after comparing the impurity effect and maneuverability of several SPE cartridges. Subsequently, the analytes were separated on a Hypersil Gold column (2.

Facile Synthesis of Non-Graphitizable Polypyrrole-Derived Carbon/Carbon Nanotubes for Lithium-ion Batteries.

Graphite is usually used as an anode material in the commercial lithium ion batteries (LIBs). The relatively low lithium storage capacity of 372 mAh g(-1) and the confined rate capability however limit its large-scale applications in electrical vehicles and hybrid electrical vehicles. As results, exploring novel carbon-based anode materials with improved reversible capacity for high-energy-density LIBs is urgent task.

Design Principles of Inert Substrates for Exploiting Gold Clusters' Intrinsic Catalytic Reactivity.

Ultralow stability of gold clusters prohibits the understanding of their intrinsic reactivity (that is vital for revealing the origin of gold's catalytic properties). Using density functional theory including many-body dispersion method, we aim to ascertain effective ways in exploiting gold clusters' intrinsic reactivity on carbon nanotubes (CNTs). We find that the many body van der Waals interactions are essential for gold clusters' reactivity on CNTs and even for O2 activation on these supported clusters.

Self-grown Ni(OH)(2) layer on bimodal nanoporous AuNi alloys for enhanced electrocatalytic activity and stability.

Au nanostructures as catalysts toward electrooxidation of small molecules generally suffer from ultralow surface adsorption capability and stability. Here, we report Ni(OH)2 layer decorated nanoporous (NP) AuNi alloys with a three-dimensional and bimodal porous architecture, which are facilely fabricated by a combination of chemical dealloying and in situ surface segregation, for the enhanced electrocatalytic performance in biosensors. As a result of the self-grown Ni(OH)2 on the AuNi alloys with a coherent interface, which not only enhances adsorption energy of Au and electron transfer of AuNi/Ni(OH)2 but also prohibits the surface diffusion of Au atoms, the NP composites are enlisted to exhibit significant enhancement in both electrocatalytic activity and stability toward glucose electrooxidation.

Integrated solid/nanoporous copper/oxide hybrid bulk electrodes for high-performance lithium-ion batteries.

Nanoarchitectured electroactive materials can boost rates of Li insertion/extraction, showing genuine potential to increase power output of Li-ion batteries. However, electrodes assembled with low-dimensional nanostructured transition metal oxides by conventional approach suffer from dramatic reductions in energy capacities owing to sluggish ion and electron transport kinetics. Here we report that flexible bulk electrodes, made of three-dimensional bicontinuous nanoporous Cu/MnO2 hybrid and seamlessly integrated with Cu solid current collector, substantially optimizes Li storage behavior of the constituent MnO2.

First principles study of periodic size dependent band gap variation of Cu doped ZnO single-wall nanotube.

In this contribution, the size dependent band gap variation of (Zn(4/6)Cu(2/6)O)(L)/(Zn(5/6)Cu(1/6)O)(L) (L is the periodic size) superlattices are investigated with the change of L. The results show that the variation tendency of band gap appears a minimum in S(4) (L = 4) which is nearly a conductor. The band gap of S(3) (L = 3) and S(5) (L = 5) also decrease obviously compared to the other three configurations.

[Chemical constituents from herb of Pholidota cantonensis].

Objective: To study the chemical constituents of Pholidota cantonensis.

Method: The compounds were isolated and purified on silica gel, Sephadex LH-20, Chromatorex ODS column chromatography and the structures were determined based on the spectral and chemical evidences.

Result: Four compounds were obtained and characterized as pholidonone (1), ephemeranthoquinone (2), orchinol (3), batatasin III (4).

Antagonistic effects of methanolic extract of Polygala telephioides on morphine responses in mice.

The present study was undertaken to investigate the antagonistic effects of the methanolic extract of Polygala telephioides (PT) on morphine responses in mice. Single administration of PT tended to antagonize the morphine-induced analgesia in a hot-plate test. Moreover, PT (300 mg/kg, p.

Hepatoprotective activity of the constituents in Swertia pseudochinensis.

A new xanthone derivative was isolated together with other 13 known constituents from a Chinese natural medicine, Swertia pseudochinensis HARA. Their structures were determined based on the spectral and chemical evidences. Furthermore, respective hexane, ethyl acetate, 1-BuOH, MeOH and water extracts of S.

Lignan derivatives and a norditerpene from the seeds of Vitex negundo.

A new phenyldihydronaphthalene-type lignan, vitedoin A (1), a new phenylnaphthalene-type lignan alkaloid, vitedoamine A (2), and a new trinorlabdane-type diterpene, vitedoin B (3), were isolated from the seeds of Vitex negundo along with five known lignan derivatives (4-8). Their chemical structures were determined mainly on the basis of NMR and MS data. Compounds 1, 2, and 4-7 showed stronger antioxidative activity than alpha-tocopherol using the ferric thiocyanate method.