A light, 3-D, porous aerogel was fabricated by way of a simple approach from 1-D tungsten oxide nanowires and 2-D reduced graphene oxide sheets. The as-prepared graphene oxide, tungsten oxide ...nanowires, and tungsten oxide-reduced graphene oxide (W sub(18)O sub(49)-RG sub( O)) aerogel were characterised. The photocatalytic activities of as-prepared aerogel under visible light irradiation were investigated through the degradation of six different organic dyes including Rhodamine B, reactive black 39, reactive yellow 145, weak acid black BR, methyl orange, and weak acid yellow G. In comparison with the pure W sub(18)O sub(49) nanowires, the prepared W sub(18)O sub(49)-RGO aerogel had significantly improved photocatalytic efficiency. Also, the photocatalysis of W sub(18)O sub(49)-RGO aerogel maintained its efficiency after 30 cycles for each of the six dyes. The photocatalytic mechanism was studied by adding hole and radical scavengers: the results confirmed that the holes generated in W sub(18)O sub(49)-RGO aerogel played a key role in the visible light photocatalytic process.
A novel graphitic carbon nitride (g-C3N4) nanosheet adsorbent with a large surface area, remarkable hydrophilicity and high adsorption capacity, was presented for the removal of cadmium ions (Cd2+) ...and methylene blue (MB) from aqueous solution. Adsorption measurements were conducted systematically to study the influences of the contact time, initial concentrations of Cd2+ and MB, temperature, and pH value. The maximum adsorption capacities of g-C3N4 towards Cd2+ and MB were 94.4 and 42.1 mg g−1, respectively, at 318.5 K when the initial concentrations of Cd2+ and MB were 200 and 20 mg L−1, respectively. The adsorption kinetics fit a pseudo-second-order model. The high adsorption performance of the g-C3N4 adsorbent can be attributed to the multiple adsorption sites on g-C3N4, including the π-π conjugate interactions and electrostatic attractions with pollutants in water. In addition, it is significant to achieve high adsorption performance of g-C3N4 nanosheets by efficiently exposing the adsorption sites by adjusting the microstructure surface properties and dispersity in solution.
Display omitted
•An eco-friendly adsorbent 2D-g-C3N4 was prepared through simple pyrolysis.•2D-g-C3N4 can effectively remove Cd2+ and MB from water.•The adsorption mechanisms of Cd2+ and MB were proposed.
•Black TiO2were prepared by one-step aluminothermic reduction.•Only the oxygen partial pressure at micro-region of TiO2-NTAs surface was changed.•Ti3+ is induced by oxygen vacancies in experiment but ...not additional intercalation.•Black TiO2 shows efficient photocatalytic CO2 reduction activity (185.39 μmol g−1 h−1).
In this work, black titania nanotube arrays (B-TiO2NTAs) were prepared by aluminothermic reduction of anodized TiO2-NTAs. It was found that the oxygen partial pressure atmicro-region of TiO2-NTAs surfacewas critical for the creation of black TiO2 NTAs. The oxygen vacancies in the prepared B-TiO2 NTAs induced new defect energy levels in the band gap of TiO2, which reduced the band gap and broadened their visible light absorption. Furthermore, the oxygen vacancies could also act as the catalytic sites and accelerate surface reactions for the photocatalytic reduction of CO2 to CO, which also was proved by isotope experiment. Especially, B-TiO2 NTAs annealed at 600℃ showed an excellent photocatalytic CO2 reduction to CO performance with the yield of 185.39 μmol g−1 h-1 under visible light illumination because the oxygen vacancy self-doping largely enhanced three key factors in this process, including photoinduced charge generation, charge separation and transportation and interfacial reaction. This facile and versatile method could be potentially used for large scale production of colored TiO2 with a high photocatalytic CO2 reduction capability in the visible light illumination.
Abstract
Vehicle re-identification (re-id) aims to solve the problems of matching and identifying the same vehicle under the scenes across multiple surveillance cameras. For public security and ...intelligent transportation system (ITS), it is extremely important to locate the target vehicle quickly and accurately in the massive vehicle database. However, re-id of the target vehicle is very challenging due to many factors, such as the orientation variations, illumination changes, occlusion, low resolution, rapid vehicle movement, and amounts of similar vehicle models. In order to resolve the difficulties and enhance the accuracy for vehicle re-id, in this work, we propose an improved multi-branch network in which global–local feature fusion, channel attention mechanism and weighted local feature are comprehensively combined. Firstly, the fusion of global and local features is adopted to obtain more information of the vehicle and enhance the learning ability of the model; Secondly, the channel attention module in the feature extraction branch is embedded to extract the personalized features of the targeting vehicle; Finally, the background and noise information on feature extraction is controlled by weighted local feature. The results of comprehensive experiments on the mainstream evaluation datasets including VeRi-776, VRIC, and VehicleID indicate that our method can effectively improve the accuracy of vehicle re-identification and is superior to the state-of-the-art methods.
“Sweet sections” in giant shale oil provinces are preferential fields that primarily support China to increase the reserves and production of continental shale oil. Based on the study of the ...geological conditions of shale oil in the continental basins in China, it was found that the shale stratum in major oil generation windows generally has higher degrees of oil and gas accumulation, and mostly contains oil. Hydrocarbon generation and reservoir capacities are the two key parameters for evaluating and optimizing favorable shale oil provinces. The evaluation index (volume of shale stratum multiplied by total organic carbon (TOC) multiplied by total porosity) for the giant continental shale oil provinces is also proposed. It is optimized that the Upper Triassic Chang 7 Member in the south-central Ordos Basin, Lower Cretaceous Qing 1 Member in the Gulong-Changling Sag in the Songliao Basin, Middle — Lower Permian in the Junggar Basin, Da’anzhai Member of the Ziliujing Formation of Lower Jurassic in the central and northern Sichuan Basin, and Paleogene oil-rich sag in the Bohai Bay Basin are the five giant continental shale oil provinces. The word “geological sweet sections” in continental shale oil provinces of China refers to favorable shale intervals which are relatively rich in oil, with superior physical properties, and more easily modified and developed commercially under applicable economic and technological conditions. After evaluation, there are mainly two types of “geological sweet sections” of giant continental shale oil developed onshore in China. One type of “geological sweet sections” is generally mudstone with optimal physical properties or a thin tight reservoir, to which the shale oil migrates a short distance. They are medium-to-high-mature zones with a thin sandy shale stratum in the Chang 7 Member in the Ordos Basin, mixed shale stratum in the medium-mature Lucaogou Formation in the Jimsar Sag, and multi-layered mixed Paleogene shale stratum in the Bohai Bay Basin. The other type of “geological sweet sections” is generally shale oil residing in various shale reservoir spaces. This type was developed in the Qing 1 Member in the Gulong Sag and Da’anzhai Member in the north-central Sichuan Basin. Free shale oil mainly occurs in shale, sandy-carbonate lamina, micro-lamella structure, and micro-fractures. Layers with lamina, lamination, and micro-fractures are generally shale oil “geological sweet sections.” Starting from field tests and the construction of the “geological sweet sections” in giant continental shale oil provinces, the shale oil industry has been rapidly developing and will become an important supplement to domestic oil production in China.
Black garlic produced from fresh garlic under controlled high temperature and humidity has strong antioxidant properties. To determine these compounds, five fractions (from F1 to F5) were separated ...and purified by elution with chloroform:methanol at different ratios (8:1, 6:1, 4:1, 2:1, and 0:1; v/v). The antioxidant activity of each fraction was analyzed. The results showed that F3 and F4 had higher phenolic contents and stronger 2,2-diphenyl-2-picrylhydrazyl radical scavenging activity than the others. Seven purified individual components were further separated using semipreparation high-performance liquid chromatography from these two intensely antioxidant fractions (F3 and F4), their structures were elucidated by high-performance liquid chromatography coupled to diode array detection, electrospray ionization, mass spectrometry, 1H nuclear magnetic resonance, and 13C nuclear magnetic resonance spectrometry. Three compounds including adenosine, uridine, and 2-acetylpyrrole were first identified in black garlic, except for 5-hydroxymethylfurfural, (1S, 3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid, and (1R, 3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid. The cellular antioxidant activities of uridine, adenosine, carboline alkaloids, 5-hydroxymethylfurfural, and ethyl acetate extracts were consistent with the results of in vitro experimental antioxidant properties. The results provide useful information for understanding the health benefits of black garlic products.
Black garlic has antioxidant activity. Seven materials were isolated and identified with silica gel, semiprep-HPLC, HPLC–DAD–ESI–MS analysis, and NMR from the ethyl acetate extraction of black garlic; adenosine, uridine, and 2-acetylpyrrole were first isolated and identified in black garlic. Display omitted
Abstract
PM
2.5
is the main particulate air pollutant whose aerodynamic diameter is less than 2.5 micron. The inflammation of various respiratory diseases are associated with PM
2.5
inhalation. ...Pro-inflammatory cytokine IL-1β generated from effected cells usually plays a crucial role in many kinds of lung inflammatory reactions. The exacerbation of Th immune responses are identified in some PM
2.5
related diseases. To elucidate the underlying mechanism of PM
2.5
-induced acute lung inflammation, we exposed Balb/c mice to PM
2.5
intratracheally and established a mice model. Acute lung inflammation and increased IL-1β expression was observed after PM
2.5
instillation. Regulatory factors of IL-1β (TLR4/MyD88 signaling pathway and NLRP3 inflammasome) participated in this lung inflammatory response as well. Treatment with compound essential oils (CEOs) substantially attenuated PM
2.5
-induced acute lung inflammation. The decreased IL-1β and Th immune responses after CEOs treatment were significant. PM
2.5
may increase the secretion of IL-1β through TLR4/MyD88 and NLRP3 pathway resulting in murine airway inflammation. CEOs could attenuate the lung inflammation by reducing IL-1β and Th immune responses in this model. This study describes a potentially important mechanism of PM
2.5
-induced acute lung inflammation and that may bring about novel therapies for the inflammatory diseases associated with PM
2.5
inhalation.
The hybrid Ensemble Kalman Filter ‐ Variational (EnKF‐Var) data assimilation (DA) system based on Grid‐point Statistical Interpolation (GSI) is extended for the Hurricane‐WRF model (HWRF). Background ...ensemble forecasts initialized by the EnKF are used to provide the flow‐dependent error covariance to be ingested by GSI using the extended control variable method. The hybrid system is then applied to assimilate airborne radar data.
In this article, the newly developed HWRF hybrid system capable of assimilating airborne radar observations is introduced. The impact of using variously estimated background error covariances on tropical cyclone (TC) core analyses and subsequent forecasts is explored by a detailed study of Hurricane Sandy (2012) and by systematic comparison of various sensitivity experiments for multiple cases during the 2012–2013 seasons. The hybrid system using the HWRF EnKF ensemble covariance (Hybrid‐HENS) is able to correct both the wind and mass fields in a dynamically and thermodynamically coherent fashion. In contrast, the wind and pressure adjustments by GSI three‐dimensional variation (GSI3DVar) using the static covariance are inconsistent. The wind and pressure relation in the covariances derived from the GFS ensemble (Hybrid‐GENS) improves upon the static covariance, but is still inconsistent compared to that of HWRF. Verifications against independent flight‐level and Stepped Frequency Microwave Radiometer (SFMR) wind data, and Hurricane Research Division (HRD) radar wind composite reveal that the Hybrid‐HENS system improves the analysed TC structure upon both GSI3DVar and Hybrid‐GENS. Hybrid‐HENS and Hybrid‐GENS improve the track, minimum sea‐level pressure (MSLP) and Vmax forecast relative to GSI3DVar. Hybrid‐HENS further improves track forecasts compared to Hybrid‐GENS. Hybrid‐HENS provides the largest positive impact of the airborne radar data. In comparison, GSI3DVar shows consistently negative impact of the data when analysing the structure and verifying track forecasts. Blending the static background error covariance in the hybrid system improves the maximum wind forecast while little benefit is found in the analysed structures and the MSLP and track forecasts.
PDF
