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Dents are one of the most common defects on pipelines and compromise the structural integrity. To date, relevant studies on failure assessment of dented pipelines have been limited, and the existing standard, mainly American Society of Mechanical Engineering (ASME) B31.8, contains major problems, making assessment results not sufficiently accurate and reliable. In this work, a new method based on ductile damage failure indictor (DFDI) criterion combined with improved strain determination by a finite element (FE) model was developed for pipeline dent assessment. Dents with different depths were created by applying a spherical indenter of 100 mm in diameter on a pipe segment of 720 mm in outer diameter and 8.1 mm in pipe wall thickness. The DFDI formula considers the influence of spring-back upon removal of indenter, and the difference between the equivalent strain at dent apex and the maximum equivalent strain at the whole dent area. When the indenter displacement is smaller than 8% of pipe outer diameter, the maximum DFDI can be determined from the equivalent strain at the dent apex. When the initial displacement exceeds 8% of the pipe outer diameter, the maximum equivalent strain at the dent area, which deviates from the dent apex, should be determined by the FE model. Moreover, the limitations of ASME B31.8 in dent assessment were explained.

Non-noble-metal-based electrocatalysts with superior oxygen reduction reaction (ORR) activity to platinum (Pt) are highly desirable but their fabrications are challenging and thus impeding their applications in metal-air batteries and fuel cells. Here, we report a facile molten salt assisted two-step pyrolysis strategy to construct carbon nanosheets matrix with uniformly dispersed Fe3N/Fe nanoparticles and abundant nitrogen-coordinated Fe single atom moieties (Fe@FeSA-N-C). Thermal exfoliation and etching effect of molten salt contribute to the formation of carbon nanosheets with high porosity, large surface area and abundant uniformly immobilized active sites. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) image, X-ray absorption fine spectroscopy, and X-ray photoelectron spectroscopy indicate the generation of Fe (mainly Fe3N/Fe) and FeSA-N-C moieties, which account for the catalytic activity for ORR. Further study on modulating the crystal structure and composition of Fe3N/Fe nanoparticles reveals that proper chemical environment of Fe in Fe3N/Fe notably optimizes the ORR activity. Consequently, the presence of abundant FeSA-N-C moieties, and potential synergies of Fe3N/Fe nanoparticles and carbon shells, markedly promote the reaction kinetics. The as-developed Fe@FeSA-N-C-900 electrocatalyst displays superior ORR performance with a half-wave potential (E1/2) of 0.83 V versus reversible hydrogen electrode (RHE) and a diffusion limited current density of 5.6 mA cm−2. In addition, a rechargeable Zn-air battery device assembled by the Fe@FeSA-N-C-900 possesses remarkably stable performance with a small voltage gap without obvious voltage loss after 500 h of operation. The facile synthesis strategy for the high-performance composites represents another viable avenue to stable and low-cost electrocatalysts for ORR catalysis.

Pain is the common indicator of inflammatory ailments and traumatic tissue injuries. The dieckol is an important therapeutic compound, which present in many seaweeds. The present research work was planned to assess the anti-inflammatory and anti-nociceptive actions of dieckol by using animal model. The anti-nociceptive action of dieckol was investigated by acetic acid triggered writhing, formalin provoked nociception, tail immersion test, hot-plate methods and the anti-inflammatory effects was explored by carrageenan triggered paw edema method. In the present investigation the administration of dieckol was remarkably suppressed and inhibited the acetic acid-provoked writhing, formalin-triggered nociception, tail immersion test, hot plate-provoked nociception in the experimental animals. The dieckol was significantly (p < 0.05) inhibited the carrageenan-triggered inflammation, leukocyte infiltration and diminished the formation of pro-inflammatory regulators in the experimental animals. Altogether, the dieckol was showed a potent anti-nociceptive and anti-inflammatory activity.

Motivation: This paper proposes a motion artifact removal (MAR) algorithm and its evaluation method for wearable functional near infrared spectroscopy (fNIRS) system. Methods: Two types of motion artifacts (MAs) and their characteristics have been investigated, and a coarse/fine dual-stage MAR method is proposed, which can remove the MAs with different features and magnitudes to protect the original data from damage. In addition, an evaluation method is also proposed based on the classification of 4 mental tasks, which objectively quantize the performance of the MAR algorithms. Results: With the proposed MAR algorithm, the mental-task classification accuracy increased from 74.73% to 83.70% in average.

Cu-based electrocatalysts can effectively facilitate carbon dioxide electrochemical reduction (CO2ER) to produce multi-carbon products. However, the roles of Cu0 and Cu+ and the mechanistic understanding remain elusive. This paper describes the controllable construction of Cu0-Cu+ sites derived from the well-dispersed cupric oxide supported on copper phyllosilicate lamella to enhance CO2ER performance. Specifically, 20% Cu/CuSiO3 shows the superior CO2ER performance with 51.8% C2H4 Faraday efficiency at -1.1 V vs reversible hydrogen electrode (RHE) during the 6 hours-test. In situ attenuated total reflection infrared spectra and density functional theory calculations were employed to elucidate the reaction mechanism over Cu0-Cu+ sites. The enhancement in CO2ER activity is mainly attributed to the synergistic effect of Cu0-Cu+ pairs: The Cu0 site activates CO2 and facilitates the following electron transfers; while the Cu+ site strengthens the *CO adsorption to further boost C-C coupling. This paper provides an efficient strategy to rationally design Cu-based catalysts with viable valence states to boost CO2ER.

The present study investigated the mechanisms by which large- and small-sized nanoscale hydroxyapatite (nHA) suppressed Fusarium-induced wilt disease in tomato. Both nHA sizes at 9.3 mg/L (low) and 46.5 mg/L (high dose) phosphorus (P) were foliar-sprayed on Fusarium-infected tomato leaf surfaces three times. Diseased shoot mass was increased by 40% upon exposure to the low dose of large-sized nHA compared to disease controls. Exposure to both nHA sizes significantly elevated phenylalanine ammonialyase activity and total phenolic content in Fusarium-infected shoots by 30-80% and 40-68%, respectively. Shoot salicylic acid content was also increased by 10-45%, suggesting the potential relationship between antioxidant and phytohormone pathways in nHA-promoted defense against fungal infection. Exposure to the high dose of both nHA sizes increased the root P content by 27-46%. A constrained analysis of principal coordinates suggests that high dose of both nHA sizes significantly altered the fatty acid profile in diseased tomato. Particularly, the diseased root C18:3 content was increased by 28-31% in the large-sized nHA treatments, indicating that nHA remodeled the cell membrane as part of defense against Fusarium infection. Taken together, our findings demonstrate the important role of nHA in promoting disease suppression for the sustainable use of nHA in nanoenabled agriculture.

In the paper, the concept of Lp -dual three-mixed quermassintegrals is introduced. The formula for the Lp -dual three-mixed quermassintegrals with respect to the p-radial addition is proved. Inequalities of Lp -Minkowski, and Brunn-Minkowski type for the Lp -dual three-mixed quermassintegrals are established. The new Lp -Minkowski inequality is obtained that generalize a family of Minkowski type inequalities. The Lp -Brunn-Minkowski inequality is used to obtain a series of Brunn-Minkowski type inequalities.

The ability of chemicals to enter the blood-brain barrier (BBB) is a key factor for central nervous system (CNS) drug development. Although many models for BBB permeability prediction have been developed, they have insufficient accuracy (ACC) and sensitivity (SEN). To improve performance, ensemble models were built to predict the BBB permeability of compounds. In this study, in silico ensemble-learning models were developed using 3 machine-learning algorithms and 9 molecular fingerprints from 1757 chemicals (integrated from 2 published data sets) to predict BBB permeability. The best prediction performance of the base classifier models was achieved by a prediction model based on an random forest (RF) and a MACCS molecular fingerprint with an ACC of 0.910, an area under the receiver-operating characteristic (ROC) curve (AUC) of 0.957, a SEN of 0.927, and a specificity of 0.867 in 5-fold cross-validation. The prediction performance of the ensemble models is better than that of most of the base classifiers. The final ensemble model has also demonstrated good accuracy for an external validation and can be used for the early screening of CNS drugs.

Despite the great efforts of using DNAzyme for gene therapy, its clinical success is limited by the lack of simple delivery systems and limited anticancer efficacy. Here, we develop a simple approach for the synthesis of hybrid nanostructures that exclusively consist of DNAzyme and Cu2+ with ultra-high loading capacity. The Cu-DNAzyme nanohybrids allow to effectively co-deliver DNAzyme and Cu2+ into cancer cells for combinational catalytic therapy. The released Cu2+ can be reduced to Cu+ by glutathione and then catalyze endogenous H2 O2 to form cytotoxic hydroxyl radicals for chemodynamic therapy (CDT), while the 10-23 DNAzyme enables the catalytic cleavage of VEGFR2 mRNA and activates gene silencing for gene therapy. We demonstrate that the system can efficiently accumulate in the tumor and exhibit amplified cascade antitumor effects with negligible systemic toxicity. Our work paves an extremely simple way to integrate DNAzyme with CDT for the dual-catalytic tumor treatment.

Investigation of rock progressive damage under static confinement and strain rates facilitates the generation mechanism of natural fault damage zones. A triaxial Hopkinson bar apparatus is used to perform dynamic triaxial compression tests to examine the damage and degradation process of rocks subjected to multiple impacts. Dynamic mechanical properties are determined under a static triaxial pre-stress of (30, 20, 10) MPa and multiple dynamic loadings, with the repetitive impact velocity of 27 m/s and strain rates from 50 to 150/s. The acoustic characteristics are identified by ultrasonic measurement to qualify the damage values. The micro-crack parameters, including crack area and volumes are detected using synchrotron X-ray micro-computed tomography (μCT) to characterize the progressive damage. In addition, the microcrack orientation, density and fractal dimension are analysed from thin section. Experimental results show that dynamic stress-strain curves can be divided to elastic, nonlinear deformation and unloading phases. Dynamic peak stress, Young’s modulus and ultrasonic wave velocity decrease with increasing impact times. The high frequency of ultrasonic wave is filtered by the induced microcracks. The progressive damage and evolution of fracture networks are associated highly with microcrack initiation, propagation, branching and coalescence. Shear bands are commonly generated in granite, and tensile cracks are dominant in marble, while sandstone is mainly failed by compaction and deformation band. The absorbed energy of rock increases nonlinearly with increasing crack surface and volume. Besides, microcracks propagate primarily along the maximum principal stress; the density and fractal dimension exhibit an anisotropic distribution controlled by true triaxial confinement and dynamic impacts.

All-inorganic CsPbBr3 perovskite is an attractive emission material for high-stability perovskite light-emitting diodes (PeLEDs), due to the high thermal and chemical stability. However, the external quantum efficiencies (EQEs) of CsPbBr3 based PeLEDs are still far behind their organic–inorganic congeners. Massive defect states on the surface of CsPbBr3 perovskite grains should be the main reason. Lewis base additives have been widely used to passivate surface defects. However, systematic investigations which relate to improving the passivation effect via rational molecule design are still lacking. Here, we demonstrate that the CsPbBr3 film’s optical and electrical properties can be significantly boosted by tailoring the hardness–softness of the Lewis base additives. Three carboxylate Lewis bases with different tail groups are selected to in-situ passivate CsPbBr3 perovskite films. Our research indicates that 4-(trifluoromethyl) benzoate acid anion (TBA−) with the powerful electron-withdrawing group trifluoromethyl and benzene ring possesses the softest COO− bonding head. TBA− thus acts as a soft Lewis base and possesses a robust combination with unsaturated lead atoms caused by halogen vacancies. Based on this, the all-inorganic CsPbBr3 PeLEDs with a maximum EQE up to 16.75% and a half-lifetime over 129 h at an initial brightness of 100 cd m−2 is thus delivered.

Small cluster and periodic surface models with low coverages of intermediates are frequently employed to investigate reaction mechanisms and identify active sites on nanoparticles (NPs) in density functional theory (DFT) studies. However, diverse active sites on NPs cannot be sufficiently represented by these simple models, hampering the in-depth insights into the catalytic behavior of NPs. This paper describes the crucial roles of both model and coverage effect on understanding the nature of active sites for CO2 reduction over Au and Pd NPs using DFT calculations. Terrace sites exhibit higher selectivity for CO than edge sites on Au NPs, which is opposite to the results on Au periodic surfaces. This contradiction reveals the computational model effect on clarifying active site properties. For Pd catalysts, the coverage effect is more significant. On bare Pd NPs and periodic surfaces, the selectivity for CO at edge sites is nearly identical to that at terrace sites, whereas edge sites display higher selectivity for CO than terrace sites in the case of high CO coverages. Through considering the more realistic models and the coverage effect, we successfully describe the size effect of Au and Pd NPs on CO selectivity. More importantly, this work reminds us of the necessity of reasonable models in DFT calculations.

Facile fabrication of superwetting materials is urgently desired, which remains a challenging issue for industrial oily wastewater treatment. In this study, a novel tubular nanofibers and micro/nanospheres covered PVDF/graphene (GE) composite membrane (TPGCM) was prepared via one-step simultaneous electrospinning/electrospraying process with the polyethylene terephthalate (PET) braided tube (BrT) as the support. This simple combined technique allowed the uniform integration of PVDF micro/nanospheres and GE nanosheets into the PVDF nanofibrous network to form a 3D hierarchical micro/nano structural composite membrane. The resultant membrane exhibited superoleophilicity in air with oil contact angle of 0°, and showed under oil superhydrophobicity with corresponding contact angle of 159 ± 0.8°. Furthermore, the morphology of the covered micro/nanospheres was simply controlled by adjusting GE nanosheets content in electrospraying precursor. As-prepared TPGCM can effectively separate a series of Span-80-stabilized water-in-oil emulsions, which showed outstanding separation efficiency of up to 99.8 %. Moreover, the robust recyclability was also presented with separation efficiency of more than 99.3 % after 10 cycles. Our strategy possesses the advantages of simplicity and cost saving, avoiding complicated reaction or post treatment, thus indicating its scalable application for practical oily wastewater purification.

Creating rich vacancies and designing distinct micro-morphology are considered as effective strategies for boosting the electrochemical performances of sodium ion battery (SIB) electrode materials. In this paper, a variety of MoS2 nanostructures with different sulfur vacancies concentration and morphologies are successfully constructed by a hydrothermal method combined with various-temperature calcination treatment in a Ar/H2 mixed atmosphere. Employed as a free-standing anode for SIBs, the flower-like MoS2-x microspheres assembled by the intertwined nanosheet arrays (MoS2-x-800) delivers highest specific capacity of 525.3 mAh g−1 and rate capability, as well as extraordinarily stable cycle life with almost no loss of capacity after 420 cycles. The favorable sodium storage properties are mainly ascribed to the cooperated effects of superior intrinsic conductivity and richer active sites generated by sulfur vacancies, and numerous interspace achieved by the intersection of neighbouring nanosheets. Meanwhile, through ex situ analyses, the reversible charge/discharge mechanism of the obtained MoS2-x-800 is revealed reasonably. This work not only brings new insights into the design of high-performance electrode materials for SIBs, but also makes a great step forward in the practical applications of transition metal sulfides in energy storage systems.

Coagulation kinetics and floc properties are of great fundamental and practical importance in the field of water treatment. To investigate the performance of Fe(VI) and Fe(III) salt on particle coagulation, Malvern Mastersizer 2000 was employed to continuously and simultaneously monitor the kaolin floc size and structure change, and population balance modeling was used to investigate the coagulation mechanism. The results show dosage increase had positive effect on collision efficiency and floc strength and negative effect on restructure rate. Low shear rate resulted in higher collision efficiency and stronger floc. Low water temperature had a pronounced detrimental effect on coagulation kinetics. Temperature increase showed the most significant positive effect on collision efficiency, floc strength and restructure rate. The optimum pH zone for the coagulation was found to be between 6 and 8. Further pH increase lowered the collision efficiency and floc strength and increased the restructure rate. FeCl3 resulted in a larger ratio of the mass to volume of kaolin flocs (compactness) than those induced by ferrate. HIGHLIGHTS Population balance modeling achieved excellent approximation of coagulation process.; FeCl3 produced larger, stronger and more compact flocs than those by ferrate(VI).; Dosage increase had positive effect on collision efficiency and floc strength.; High temperature resulted in high collision efficiency, floc strength and restructure.; Optimum pH for both coagulation systems was between 6 and 8.

Spontaneous and stochastic reversal of large scale flow structure is an intriguing and crucial phenomenon in turbulent Rayleigh-Bénard type natural convection. This paper proposes a new control approach to eliminate the reversals through stabilising the corner flows using two small sidewall controllers. Based on a series of direct numerical simulations, it is shown that the control can successfully stop the growth of corner vortices and suppress the reversal of large-scale circulation, if the width of sidewall controllers installed within or near the top of corner vortices is large enough. When the controllers are located around the centre, they can easily break up the large-scale structures or even divide the single roll mode into a double-roll mode for very large widths. Moreover, the influence of sidewall controllers on the heat transport is studied. It is shown that the heat transport efficiency can be slightly enhanced or suppressed when the proper location and width are chosen. The present findings provide a new idea to control the large-scale flow structure and reversals in thermally driven convection through sidewall controlling.

Bimetallic nanoparticle catalysts attract extensive attention for relevant catalysis processes due to their flexible structures, while the structure evolution under specific conditions is ambiguous...

In recent years, the DNA detection of drowning-related diatoms, cyanobacteria and aeromonas has gradually attracted interest from forensic scientists. In this study, we described the validation and application of a novel multiplex PCR system. This system integrated 12 fluorescently labelled primers designed to amplify specific genes of diatoms, cyanobacteria and aeromonas. The specificity studies demonstrated that this multiplex PCR system could detect 9 species of diatom, 7 species of cyanobacteria and 5 species of aeromonas, all of which were drowning-related and widely distributed in various water circumstance of southern China. The sensitivity studies indicated that the limit concentration of template DNA was 0.0125 ng. Besides, this multiplex PCR system had good performance in sizing precision and stability, but it is not suitable for degraded DNA samples. The application into forensic casework showed that all the tissue samples from ten non-drowning cases showed negative results, and the positive rates of lung, liver, kidney, and water samples from thirty drowning bodies were 100%, 86.7%, 90% and 100%, respectively. Combined with results of diatom tests of MD-VF-Auto SEM method, this multiplex PCR system could help rule out non-drowning bodies and provide extra evidences to support drowning diagnosis, especially for those cases with few diatoms were observed. It is expected that this multiplex PCR system has great potential for forensic drowning diagnosis. This article is protected by copyright. All rights reserved.

The physiological and metabolic differences between shoot tips and roots of tea plants are significant, and understanding them is required for improvement of tea quality and plant growth. A high-quality full-length transcriptome sequencing on tea plant roots and shoot tips by PacBio SMRT technology was done to gain a further understanding. Approximately 160699 and 166120 full-length transcripts were recovered in roots and shoots, respectively, including 31232 and 41068 novel isoforms and 16960 and 26029 alternative splicing (AS) isoforms. These supported 21699 full-length reads and 31232 and 41068 novel transcripts from root and shoot, respectively, including 1679 long noncoding RNAs (lncRNAs) and 2772 fusion transcripts, which significantly upgrade the Camellia sinensis genome annotation. The respective 6475 and 6981 transcripts in roots and shoots differ in 3'-untranslated regions. Meanwhile, extensive analyses of novel transcripts, ASs, and lncRNAs also revealed a large number of ASs and lincRNAs closely related to the regulation of characteristic secondary metabolites including catechins, theanine, and caffeine. Finally, a root-specific CsMYB6 was characterized to regulate theanine biosynthesis by genetic and molecular analyses. CsMYB6 directly bound to and activate the promoter of theanine synthetase gene (CsTSI). The study lays a foundation for the further investigation of metabolic genomics and regulation in tea plants.

Metallic bipolar plates can significantly increase the power density of polymer electrolyte membrane fuel cells; however, they require corrosion-protection coatings with desirable physical and chemical properties. In this study, diamond-like carbon (DLC) film coatings are investigated as such coatings potentially for metallic-based bipolar plates, with the focus on the relation between the processes and properties of the coatings under different coating deposition conditions of Plasma Enhanced Chemical Vapor Depsoition (PECVD) method. Various characterization techniques are applied to study the adhesion, structure, morphology, wettability, corrosion, and electrical resistivity of the film coatings. XPS, EDAX, and SEM analyses are used to identify the ratio of sp3 (diamond-like) and sp2 (graphite-like) bonds in the coatings, surface elements, and surface morphology, respectively. Potentiodynamic polarization test is utilized to investigate the corrosion behaviors of substrates with and without DLC coatings. Further, the electrical resistivity of the DLC films is measured by the four-point probe method. The results indicate that higher deposition power along with the absence of argon gas results in more sp3 than sp2 bonds in the coating, and the electrical resistivity is increased accordingly. The coating films deposited from methane (CH4) exhibit superior adhesion to the stainless steel (SS316) substrates over those generated from acetylene (C2H2) gas. Coating films deposited on the metallic substrates change the surface wettability appreciably. Further, polarization tests show that coatings generated with a low power of 250 W and higher argon gas percentage of 30% provide better anti-corrosion protection for metallic-based bipolar plates.

The Juno spacecraft made the first in-situ observations of energetic particles in the polar region of Jupiter’s magnetosphere. After Jupiter Orbit Insertion (JOI) in July 2016, data from ~20 Juno perijoves (PJs) obtained by Juno/JEDI are accumulated, providing an excellent opportunity to study the long term spatio-temporal distribution of energetic particles in Jupiter’s radiation belt. We transform Juno’s position from a Cartesian to a magnetic coordinate system by tracing magnetic field lines based on a fourth order Runge-Kutta method. Then the fluxes of energetic electrons from PJ1 to PJ14 sorted by different locations in magnetic coordinate space and the data are well organized by the L-shell parameter. The variation of electron flux increases with L-shell. The deviation (the ratio of the 75th percentile to the 25th percentile) of 0.51 MeV electron flux varies from a factor of 1.23 near L = 9.5 to 27.57 near L = 15.5. However, the mean flux decreases by about one order of magnitude in the same region. The electron spectra at larger L-shells are softer than that at smaller L-shells. On the other hand, the electron flux decreases more rapidly with increased L-shell when the location is off the equator. Along an L-shell, the electron flux decrease at first and then increase again from equator to mid-latitude region. In addition, we compare the statistical results with the widely used GIRE2 model. JEDI data correspond well with the GIRE2 model when the L-shell is > 14.75. GIRE2 underestimate the electron flux for L-shell smaller than 13.25. These results of this analysis are applicable to estimate the effects of the radiation environment in Jupiter’s magnetosphere.

Human parsing is an important task in human-centric image understanding in computer vision and multimedia systems. However, most existing works on human parsing mainly tackle the single-person scenario, which deviates from real-world applications where multiple persons are present simultaneously with interaction and occlusion. To address such a challenging multi-human parsing problem, we introduce a novel multi-human parsing model named MH-Parser, which uses a graph-based generative adversarial model to address the challenges of close-person interaction and occlusion in multi-human parsing. To validate the effectiveness of the new model, we collect a new dataset named Multi-Human Parsing (MHP), which contains multiple persons with intensive person interaction and entanglement. Experiments on the new MHP dataset and existing datasets demonstrate that the proposed method is effective in addressing the multi-human parsing problem compared with existing solutions in the literature.

Enzymatic conversion of corn fiber to fermentable sugars is beneficial to improving the economic efficiency of corn processing. In this work, the filamentous fungus Penicillium oxalicum was found to secrete enzymes for efficient saccharification of un-pretreated corn fiber. Separate engineering of transcriptional activators ClrB, XlnR, and AraR led to enhanced production of different sets of lignocellulolytic enzymes. Particularly, the enzymes produced by XlnR- and AraR-engineered strains showed a synergistic effect in corn fiber saccharification. Combinatorial engineering of all three activators generated a strain MCAX with 3.1- to 51.0-fold increases in lignocellulolytic enzyme production compared with the parent strain. In addition, the enzymes of strain MCAX released significantly more fermentable sugars from corn fiber than those of the parent strain at the same protein dosage. The results suggest that this strain has potential for on-site production of enzymes for corn fiber saccharification.

Forsythia suspensa leaves (FSL), rich in phillyrin, forsythiaside A, phillygenin, rutin, and other compounds, is a known traditional Chinese medicine (TCM). It has been effective in heat retreat an...

Poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP)/ferric oxide (Fe2O3) hybrid flat-sheet membranes (HFM) (FEP/Fe2O3-HFM) with heterogeneous Fenton-like oxidation were fabricated by a facile hot pressing method for dye effluent treatment. The morphology and properties of the resultant membrane were found to be influenced by the addition of Fe2O3. With the increasing Fe2O3 content, the porosity, water flux and contact angle of the resultant FEP/Fe2O3-HFM will raise up but deteriorate mechanical performance. The maximum methylene blue (MB) removal efficiency (99.69%) can be achieved using 10 wt% Fe2O3 addition in membrane composition at following conditions: 40 mg L−1 MB concentration at pH 3, the dosage of 1.5 g g−1 (hydrogen peroxide, H2O2 to FEP/Fe2O3-HFM) in cross-flow filtration. In addition, FEP/Fe2O3-HFM shows commendable reusability enduring vigorous catalysis due to the inherit stability from fluorinated polymer. Due to high-efficient separation and good removal performance to high concentration of dye (e.g. 250 mg L−1 MB), our FEP/Fe2O3-HFMs show great promise in aqueous pollutant treatment by heterogeneous Fenton-like reaction.

In this perspective, we outline that a space borne gravitational wave detector network combining LISA and Taiji can be used to measure the Hubble constant with an uncertainty less than 0.5% in ten years, compared with the network of the ground based gravitational wave detectors which can measure the Hubble constant within a 2% uncertainty in the next five years by the standard siren method. Taiji is a Chinese space borne gravitational wave detection mission planned for launch in the early 2030 s. The pilot satellite mission Taiji-1 has been launched in August 2019 to verify the feasibility of Taiji. The results of a few technologies tested on Taiji-1 are presented in this paper. Gravitational wave astronomy has opened the door to test general relativity and the effect of gravity in the Universe. The authors present the capabilities of an overlap between space gravitational wave detectors LISA and Taiji to constrain the Hubble constant to 0.5%, in 10 years, and what can be learned from the satellite pilot Taiji-1 launched in 2019.

Taking the mixed pre-salt carbonate rocks in the upper member of Eocene Xiaganchaigou Formation (E32) of Yingxi area in the Qaidam Basin as an example, the lithofacies and controlling mechanisms of reservoir formation are analyzed based on a large dataset of cores, thin sections and geochemical analysis. The reservoirs in E32 pre-salt layers have five types of lithofacies, of them, mixed granular calcareous dolostone, massive calcareous dolostone, plaque calcareous dolostone, and laminated dolomtic limestone are of sedimentary origin, and breccia calcareous dolostone is of tectonic origin. The four types of sedimentary lithofacies are divided into two types of saline sedimentary sequence lithofacies combinations, low-energy type in the sag area and low to high-energy type in the slope and paleo-uplift zone in the depression. Affected by high-frequency supply of continental clastic material, the two types of salty sedimentary sequences are mostly incomplete subtypes of lithofacies. Lithofacies have strong impacts on pre-salt reservoirs in E32: (1) Lithofacies type and sedimentary sequence controlled the formation and distribution of dolomite intercrystalline pores and dissolved pores during the pene-sedimentary period. (2) The structure of laminated dolomitic limestone controlled the formation of large-scale laminated fractures and high permeability channels during the diagenetic period. (3) Granular, massive, plaque calcareous dolostones have low mud content and strong brittleness, in the late tectonic reactivation period, the distribution of the three types of lithofacies, together with their distance from the top large slip faults and secondary faults, controlled the formation and distribution of high-efficiency fracture-cave brecciaed calcareous dolostone reservoirs. The above research led to the composite lithofacies-tectonic formation model of pre-salt reservoir in E32 of Yingxi area. The tempo-spatial distribution of tectonic breccia calcareous dolostone reservoirs, laminated dolomitic limestone shale oil reservoirs and granular, massive calcareous dolostone dissolved-intercrystalline pore tight reservoirs in various structural belts of the studied area have been figured out. These findings gave new insights into tight-shale oil accumulation theory in mixed carbonate successions from saline lacustrine basins, aiding in high efficient exploration and development of petroleum in the studied area.

Summary Propane dehydrogenation (PDH) is a commercial propylene production technology that has received much attention, but high reaction temperatures result in a decrease of propylene selectivity and catalyst stability. This paper describes a single-site [PtZn4] catalyst by assembling atomically ordered intermetallic alloy (IMA) as a selective and ultrastable PDH catalyst. The catalyst enables more than 95% of propylene selectivity from 520°C to 620°C. No obvious deactivation is observed within the 160-h test, superior to PtSn/Al2O3 and state-of-the-art Pt-based catalysts. Based on in situ X-ray absorption fine structure, X-ray photoelectron spectroscopy measurements, and density functional theory calculations, we reveal that the surface [PtZn4] ensembles in PtZn IMAs serve as the key active site structures, wherein the geometry-isolated and electron-rich Pt1 site in [PtZn4] ensembles readily promotes the first and second C–H cleavage of propane but inhibits further dehydrogenation of surface-bounded propylene. This significantly improves the selectivity and stability by prohibiting coke side reactions.

Since transmission towers are generally located in areas with complex geological environments, such as mountains and rivers, relying only on conduct regular personnel inspections wastes considerable human and material resources. At present, the existing monitoring system has also the problems of data transmission, parameter accuracy and transmission distance. Based on this premise, a novel transmission tower tilt monistoring system was proposed in this paper. This research adopted the latest Low-Power Wide-Area Network (LPWAN) technology. Among tehm, LoRa (Long Range) is a modulation technology that provides a longer communication distance. NB-IoT (Narrow Band-Internet of Things) technology is an emerging technology in the IoT field that supports the cellular data connection of low-power devices in a wide area network. The proposed system through the data transmission of a LoRa multinode network, the tilt parameters of tower were uploaded to an online real-time monitoring system through NB-IoT. Each subnode included MPU6050 tilt sensors and a wireless communication LoRa module. The main node contained an NB-IoT module. It can upload the tilt information to the cloud platform. After uploading the data, administrators can arrange timely targeted maintenance for transmission towers with faults according to the analysis results. The proposed approach covers a wide range, has high service quality, and supports many connections.

We designed and fabricated non-precious and highly efficient electrocatalysts of nickelmolybdenum/copper-nanosheets/nickel-foam composites (NiMo/Cu-NS/NF) by step electrodepositions, combining with chemical oxidation method. The catalysts were charaterized by means of SEM, XRD and XPS spectra. Their electrocatalytic activities were assessed by hydrogen evolution reactions (HER) over a wide pH range, where acidic, neutral and alkaline electrolytes were used, respectively. Benefiting from the unique midlayer Cu nanosheets (NS) architecture and optimum Mo–Ni composition at the surface layer which led to high electronic conductivity and large electrochemically active surface area (ECSA), the NiMo/Cu-NS/NF-2 catalyst displayed superior electrocatalytic activities with low overpotentials of η10 = 43, 86 and 89 mV in 0.5 M H2SO4, 1.0 M PBS and 1.0 M KOH electrolyte, respectively. Especially in the acidic condition, it exhibited the best electrocatalytic activity with smaller Tafel slope of 54 mV dec−1 and higher exchange current density of 1.93 mA cm−2.

The toxic mechanisms of functionalized polystyrene nanoplastics (NPs) in bivalves, especially regarding energy homeostasis and immunity in benthic marine ecosystem, are poorly understood. Therefore, in this study, the toxicity effects of two amino-modified and carboxylated polystyrene NPs (PS-NH2 and PS-COOH) on clams (Meretrix meretrix) at individual, organic, cellular, and gene levels were investigated at environmentally relevant NP concentrations of 0.02–2 mg L−1. The exposure of both NPs showed non-lethal effect but inhibited the clam growth. Little difference in the toxic effect was observed between the two NPs, mainly due to their similar bioaccessibility. The inhibition of clam growth was mainly driven by the energy homeostasis imbalance via the atrophic inflammation of digestive glands induced by the bioaccumulation of NPs. The immunomodulation dysfunction, manifested as decreased phagocytosis resulting from the lysosomal membrane destabilization, was also responsible for the inhibited growth. Furthermore, the mechanisms of genotoxicity were identified to be energy homeostasis imbalance triggered by pancreatic secretion, tricarboxylic acid cycle (TCA) cycle, and peroxisome proliferator activated-receptor α (PPARα) signaling pathway, and the immunomodulation dysregulation dominated by the constrained toll-like receptors (TLR) and nuclear factor-kappa B (NF-κB) signaling pathway, phagosome and lysosome pathway. This work has expanded the current understanding of the toxic mechanisms of functionalized NPs in bivalves, highlighting the potential risks of the NPs in the stability and function of marine benthic ecosystems, even food security.

Automatic route planning and tracking control are important for unmanned surface vehicles (USVs). This study presents a final-optimized A* (FO A*) algorithm for automatic route planning of USVs and designs a nonlinear tracking controller to ensure that the ship navigates on the route. Ship domain theory is employed in the FO A* algorithm to ensure that the planning route is far from shorelines and reefs. Meanwhile, water depth is used to determine the safety area in the search process. The nonlinear feedback algorithm is also applied to reduce the rudder angle when the ship tracks the planning route in wind and waves. Finally, the proposed algorithms are well validated on the ship-based Electronic Chart Display and Information System (ECDIS). The experiment shows that the FO A* algorithm and the nonlinear tracking controller are effective and deterministic for route planning offline. It can be put into navigation practice, which will make some contribution in accelerating the USV development.

Novel Ce-mediated Fe-MIL-101 (Fe/Ce-MIL-101) Fenton catalysts were synthesized to efficiently remove norfloxacin (NOR). The substitution of Ce remarkably enhanced the catalytic performance of Fe-MIL-101, and the degradation efficiency of NOR (10 mg L−1) increased from 50.1% to 94.8% within 60 min. NOR could be completely degraded by Fe/Ce-MIL-101 after 180 min. Moreover, Fe/Ce-MIL-101 showed excellent stability and reusability in simulated and actual wastewater samples. Density functional theory (DFT) calculations revealed that the introduction of Ce(III) and formation of hetero-coordinated Fe–O–Ce moieties in the secondary building units (SBUs) of Fe-MIL-101 could induce electronic distribution asymmetry, benefit the interaction between the metal sites and H2O2, accelerate electron transfer, and further facilitate H2O2 activation. The degradation pathways of NOR were identified based on liquid chromatography-mass spectrometry (LC-MS) analysis and Fukui function calculation. Nine benzene ring-containing intermediates were initially detected after 20 min of degradation, and only two byproducts (“harmless” category) were preserved after 180 min. The opening of the piperazine ring and transformation of the quinolone group were mainly caused by the formed hydroxyl free radicals (˙OH). This work demonstrates a new strategy to enhance the performance of Fe-based Fenton-like catalysts by mediating the asymmetrical electronic distribution of coordinated Fe sites.

Organic aerosols, a major constituent of fine particulate mass in megacities, can be directly emitted or formed from secondary processing of biogenic and anthropogenic volatile organic compound emissions. The complexity of volatile organic compound emission sources, speciation and oxidation pathways leads to uncertainties in the key sources and chemistry leading to formation of organic aerosol in urban areas. Historically, online measurements of organic aerosol composition have been unable to resolve specific markers of volatile organic compound oxidation, while offline analysis of markers focus on a small proportion of organic aerosol and lack the time resolution to carry out detailed statistical analysis required to study the dynamic changes in aerosol sources and chemistry. Here we use data collected as part of the joint UK-China Air Pollution and Human Health (APHH-Beijing) collaboration during a field campaign in urban Beijing in the summer of 2017 alongside laboratory measurements of secondary organic aerosol from oxidation of key aromatic precursors (1,3,5-Trimethyl benzene, 1,2,4-Trimethyl benzene, propyl benzene, isopropyl benzene and 1-methyl naphthalene) to study the anthropogenic and biogenic contributions to organic aerosol. For the first time in Beijing, this study applies positive matrix factorisation to online measurements of organic aerosol composition from a time-of-flight iodide chemical ionisation mass spectrometer fitted with a filter inlet for gases and aerosols (FIGAERO-ToF-I-CIMS). This approach identifies the real-Time variations in sources and oxidation processes influencing aerosol composition at a near-molecular level. We identify eight factors with distinct temporal variability, highlighting episodic differences in OA composition attributed to regional influences and in situ formation. These have average carbon numbers ranging from C5-C9 and can be associated with oxidation of anthropogenic aromatic hydrocarbons alongside biogenic emissions of isoprene, α-pinene and sesquiterpenes. This journal is

Silicon is a promising photocathode material in photoelectrochemical water splitting for hydrogen production, but it is primarily limited by photocorrosion in aqueous electrolytes. As an extensively used protective material, crystalline TiO2 could protect Si photoelectrode against corrosion. However, a large number of grain boundaries (GBs) in polycrystalline TiO2 would induce excessive recombination centers, impeding the carrier transport. This paper describes the introduction of oxygen vacancies (Ovac ) with controllable spatial distribution for GBs to promote carrier transport. Two kinds of Ovac distribution, Ovac along GBs and Ovac inside grains, are compared, where the latter one is demonstrated to facilitate carrier transport owing to the formation of tunneling paths across GBs. Consequently, a simple p-Si/TiO2 /Pt heterojunction photocathode with controllable Ovac distribution in TiO2 shows a +400 mV onset potential shift and yields an applied bias photon-to-current efficiency of 5.9 %, which is the best efficiency reported among silicon photocathodes except for silicon homojunction.

For resonant mass sensors, a frequency sweeping procedure is usually required to identify the frequency shift in a relative frequency range, which is not suitable for detecting incremental mass. The impedance detection method can measure mass at a fixed frequency. To further explore such sensing mechanism, the main geometrical parameters influencing the impedance sensitivity have been carefully analyzed considering the electro-mechanical coupling effects, and a series of design rules have been proposed for improving sensitivity, e.g. increasing the cantilever length and piezoelectric thickness, which is contrary to the traditional method of minimizing the geometric size for frequency based sensors. Three macro-sized sensors with 21.0 mm, 26.0 mm and 30.0mm long cantilevers are fabricated, and the measured impedance sensitivities are $212.7\Omega $ /mg, $514.8\Omega $ /mg and $737.4\Omega $ /mg that are increasing with the cantilever length, thus validating the design rules on cantilever length. However, the frequency sensitivities are 14.0 Hz/mg, 9.2 Hz/mg, and 7.2 Hz/mg that are decreasing with the cantilever length. Furthermore, the impedance sensitivity is much higher than the frequency sensitivity, and the design map of the sensor is presented as an overall guideline for structure optimization.

ADP-mediated platelet aggregation is signaled through G protein-coupled receptors P2Y1 and P2Y12 on the platelet. The clinical effectiveness of inhibiting P2Y12 has been well established, and preclinical studies indicated that the inhibition of P2Y1 could provide equivalent antithrombotic efficacy as P2Y12 antagonists and reduce bleeding risks. On the basis of the 2-phenyl-1H-imidazole scaffold of our previously reported xanthine oxidase inhibitor WSJ-557, we first achieved the transition from the xanthine oxidase inhibitors to dual-target antagonists against P2Y1 and P2Y12. We described the structure-activity relationships of the 2-phenyl-1H-imidazole compounds, which led to the identification of the most potent antiplatelet agents, 24w and 25w, both showing a rapid onset of action in pharmacokinetic study. Furthermore, the rat model suggested that 24w demonstrated a wider therapeutic window than ticagrelor, displaying equivalent and dose-dependent antithrombotic efficacy with lower blood loss compared to ticagrelor at same oral dose. These results supported that 24w and 25w could be promising drug candidates.

A major field of current research in chemistry and biology is the development of the tools that enable in situ analysis of complex systems. However, the long-time dynamics simulation for an extremely large system in solution is almost impossible by an all-atom force field combined with an explicit solvent model. The results show that the larger the periodic box is, the closer the properties of the system are to the experimental values. Therefore, how can we carry out simulations for systems that are fast, accurate, and large enough? A method of dividing the periodic box into subdivisions with their surroundings (DBSS) is presented here, and it clearly increases the computation speed without losing accuracy and enables the simulation of extremely large systems by strongly decreasing the dimension of the charge matrix. The DBSS method divides a single periodic box or unit in an extremely large system into several subdivisions with a suitable choice according to atomic coordinates. This method ensures that these subdivisions are always changing and allows the atoms to communicate with each other. Intermolecular communication is important for molecular properties and functions but is not possible with other fragment methods. The partial charges are calculated in each subdivision with an overlapping surrounding used to take hydrogen bond interaction between the subdivisions into account. This is an iterative process because the charge population will be recalculated at intervals during the dynamics simulations. Taking a water system as an example, each subdivision is extended by 4 Å as the surrounding. The computation time scales almost linearly with the size of the system, and the slope is small. MD simulations for several properties have been performed by the ABEEM-DBSS method. The results indicate that the ABEEM-DBSS method can accurately simulate the properties of water system, and the accuracy can reach or approach that of the experimental data or of other water potentials. Interestingly, the properties become closer to the experimental data as the sizes of the periodic box increase, further validating the need for the simulation of a large system and demonstrating the value of the DBSS method.

Subtle ligand modifications on RuII -polypyridyl complexes may result in different excited-state characteristics, which provides the opportunity to tune their photo-physicochemical properties and subsequently change their biological functions. Here, a DNA-targeting RuII -polypyridyl complex (named Ru1) with highly photosensitizing 3 IL (intraligand) excited state was designed based on a classical DNA-intercalator [Ru(bpy)2 (dppz)]⋅2 PF6 by incorporation of the dppz (dipyrido[3,2-a:2',3'-c]phenazine) ligand tethered with a pyrenyl group, which has four orders of magnitude higher potency than the model complex [Ru(bpy)2 (dppz)]⋅2 PF6 upon light irradiation. This study provides a facile strategy for the design of organelle-targeting RuII -polypyridyl complexes with dramatically improved photobiological activity.

Black carbon (BC) particles in Beijing summer haze play an important role in the regional radiation balance and related environmental processes. Understanding the factors that lead to variability of the impacts of BC remains limited. Here, we present observations by a soot-particle aerosol mass spectrometer (SP-AMS) of BC-containing submicron particulate matter (BC−PM1) in Beijing, China, during summer 2017. These observations were compared to concurrently measured total non-refractory submicron particulate matter (NR−PM1) by a high-resolution aerosol mass spectrometer (HR-AMS). Distinct properties were observed between NR−PM1 and BC−PM1 relevant to organic aerosol (OA) composition. Hydrocarbon-like OA (HOA) in BC−PM1 was found to be up to 2-fold higher than that in NR−PM1 in fresh vehicle emissions, suggesting that a part of HOA in BC−PM1 may be overestimated, likely due to the change of collection efficiency of SP-AMS. Cooking-related OA was only identified in NR−PM1, whereas aged biomass burning OA (A-BBOA) was a unique factor only identified in BC−PM1. The A-BBOA was linked to heavily coated BC, which may lead to enhancement of the light absorption ability of BC by a factor of 2 via the “lensing effect”. More-oxidized oxygenated OA identified in BC-containing particles was found to be slightly different from that observed by HR-AMS, mainly due to the influence of A-BBOA. Overall, these findings highlight that BC in urban Beijing is partially of agricultural fire origin and that a unique biomass-burning-related OA associated with BC may be ubiquitous in aged BC−PM1, and this OA may play a role in affecting air quality and climate that has not previously been fully considered.

Cluster-based metal–organic frameworks (MOFs) supported by mixed ligands usually have unique properties due to the combined features from different ligands. In this regard, it is rather rare for ca...

Metal oxides are widely employed in heterogeneous catalysis, but it remains challenging to determine their exact structure and understand the reaction mechanisms at the molecular level due to their structural complexity, in particular for binary oxides. This paper describes the observation of the strong electronic interaction between In2O3 and monoclinic ZrO2 (m-ZrO2) by quasi-in-situ XPS experiments combined with theoretical studies, which leads to support-dependent methanol selectivity. In2O3/m-ZrO2 exhibits methanol selectivity up to 84.6% with a CO2 conversion of 12.1%. Moreover, at a wide range of temperatures, the methanol yield of In2O3/m-ZrO2 is much higher than that of In2O3/t-ZrO2 (t-: tetragonal), which is due to the high dispersion of the In-O-In structure over m-ZrO2 as determined by in situ Raman spectra. The electron transfer from m-ZrO2 to In2O3 is confirmed by XPS and DFT calculations and improves the electron density of In2O3, which promotes H2 dissociation and hydrogenation of formate intermediates to methanol. The concept of the electronic interaction between an oxide and a support provides guidelines to develop hydrogenation catalysts.

Microstructure changes in catalyst layers limit durability which is essential for the commercialization of polymer electrolyte membrane fuel cells. In this study, a mathematical model is developed for the mechanical changes in the microstructure of catalyst layers resulting from variations in clamping force, temperature and relative humidity. Finite element method is adopted and cohesive zone model is used to simulate the microstructure behavior, including the occurrence of delamination between different structures and phases as well as within the ionomer due to its breakdown (crack initiation). It is shown that subject to a startup and shutdown cycle, the interface between the ionomer and catalyst agglomerate can start to delaminate near the end of the shutdown process, and the change in the relative humidity is the dominant factor that influences the delamination process, because the ionomer in the catalyst layer structure expands and shrinks with its water content. The delamination between the ionomer and catalyst agglomerate is found to propagate or increase with the number of the startup and shutdown cycles, and nearly 90% of the interface delaminates after 100 cycles. The plastic strain inside the ionomer, which is not fully recoverable, accumulates (increases) with the cycling, although it is smaller than the breakdown strain of the ionomer after 100 cycles, it may lead to the internal crack initiation if the cycling continues.

In the past few decades, evolutionary multi-objective optimization has become a research hotspot in the field of evolutionary computing, and a large number of multi-objective evolutionary algorithms (MOEAs) have been proposed. However, MOEA is still faced with the problem that the diversity and convergence of non-dominated solutions are difficult to balance. To address these problems, an efficient multi-objective optimization algorithm based on level swarm optimizer (EMOSO) is proposed in this paper. In EMOSO, a sorting method is introduced to balance the diversity and convergence of non-dominated solutions in the whole population, which is based on non-dominated relationship and density estimation. Meanwhile, a level-based learning strategy is introduced to maintain the search for non-dominated solutions. Finally, DTLZ, ZDT and WFG series problems are utilized to verify the performance of the proposed EMOSO. Experimental results and statistical analysis indicate that EMOSO has competitive performance compared with 6 popular MOEAs. The source code of EMOSO is provided at: https://github.com/xuweizhang163/EMOSO .

Hydraulic support plays a key role in ground control of longwall mining. The smart prediction methods of support load are important for achieving intelligent mining. In this paper, the hydraulic support load data is decomposed into trend term, cycle term, and residual term, and it is found that the data has clear trend and period features, which can be called time series data. Based on the autoregression theory and weighted moving average method, the time series model is built to analyze the load data and predict its evolution trend, and the prediction accuracy of the sliding window model, ARIMA (Autoregressive Integrated Moving Average) model, and SARIMA (Seasonal Autoregressive Integrated Moving Average) model to the hydraulic support load under different parameters are evaluated, respectively. The results of single-point and multipoint prediction test with various sliding window values indicate that the sliding window method has no advantage in predicting the trend of the support load. The ARIMA model shows a better short-term trend prediction than the sliding window model. To some extent, increasing the length of the autoregressive term can improve the long-term prediction accuracy of the model, but it also increases the sensitivity of the model to support load fluctuation, and it is still difficult to predict the load trend in one support cycle. The SARIMA model has better prediction results than the sliding window model and the ARIMA model, which reveals the load evolution trend accurately during the whole support cycle. However, there are many external factors affecting the support load, such as overburden properties, hydraulic support moving speed, and worker’s operation. The smarter model of SARIMA considering these factors should be developed to be more suitable in predicting the hydraulic support load.

The membrane fouling is a notorious problem in the practical application of separation membranes. In this study, a mixed matrix membrane based on the MOF BUT-8(A) and the polymer polydiallyldimethylammonium chloride (PDDA) has been prepared on a hydrolyzed polyacrylonitrile (HPAN) substrate by the spin-assisted layer-by-layer assembly (spin-LbL) method. Thanks to the high porosity, high stability, moderate hydrophilicity, and electronegative nature of BUT-8(A), and the good compatibility between BUT-8(A) particles and PDDA polyelectrolytes, the prepared (BUT-8(A)/PDDA)3-HPAN membrane showed high water permeances (over 164 L m−2 h−1 MPa−1) and high rejection rates (over 91.4%) for many dyes in water. Furthermore, the membrane exhibited superior antifouling performance in nanofiltration (NF) with a high flux recovery rate (95.5%) when humic acid (HA) was used as foulant. The high antifouling performance is resulted from tuning hydrophilicity and electronegativity of the membrane surface. These results suggest that the nanofiltration performance of a MOF-based membrane can be well adjusted by a judicious choice of the membrane components and fabrication methods.

High sintering temperatures and high pressures are often needed for the densification of SiC. The sintering of SiC can be facilitated by adding Al2O3–Y2O3 oxides as the sintering additives. In the present study, the SiC@Al2O3–Y2O3 composite nanoparticles with a core-shell structure were designed and prepared using a slow co-precipitation method in the presence of urea. It was found that by slowing down the hydrolysis rate of the metal ions, Al(OH)3 and Y(OH)3 could be co-precipitated and uniformly coated on the surface of the SiC nanoparticles by a heterogeneous nucleation mechanism. After subsequent heat treatment, SiC@Al2O3–Y2O3 nanoparticles with amorphous Al2O3–Y2O3 layers of 2–3 nm were obtained. SiC ceramics with different oxides aids were prepared by sintering the core-shell nanoparticles at 1800–1900 °C under a pressure of 30 MPa. For SiC with higher additives of 20 wt%, evident volatilization of the oxide aids occurred at high temperatures with the segregation of the oxides. For the sample sintered at 1800 °C, dense SiC ceramics with uniform sintering aids distribution were obtained with the Al2O3–Y2O3 content as low as 5 wt% and a surface Vickers hardness of 31.5 GPa was obtained.

Chemical looping provides an energy- and cost-effective route for alkane utilization. However, there is considerable CO2 co-production caused by kinetically mismatched O2- bulk diffusion and surface reaction in current chemical looping oxidative dehydrogenation systems, rendering a decreased olefin productivity. Sub-monolayer or monolayer vanadia nanostructures are successfully constructed to suppress CO2 production in oxidative dehydrogenation of propane by evading the interference of O2- bulk diffusion (monolayer versus multi-layers). The highly dispersed vanadia nanostructures on titanium dioxide support showed over 90 % propylene selectivity at 500 °C, exhibiting turnover frequency of 1.9×10-2 s-1 , which is over 20 times greater than that of conventional crystalline V2 O5 . Combining in situ spectroscopic characterizations and DFT calculations, we reveal the loading-reaction barrier relationship through the vanadia/titanium interfacial interaction.

Obtaining genetic variation information from indica rice hybrid parents and identification of loci associated with heterosis are important for hybrid rice breeding. Here, we resequence 1,143 indica accessions mostly selected from the parents of superior hybrid rice cultivars of China, identify genetic variations, and perform kinship analysis. We find different hybrid rice crossing patterns between 3- and 2-line superior hybrid lines. By calculating frequencies of parental variation differences (FPVDs), a more direct approach for studying rice heterosis, we identify loci that are linked to heterosis, which include 98 in superior 3-line hybrids and 36 in superior 2-line hybrids. As a proof of concept, we find two accessions harboring a deletion in OsNramp5, a previously reported gene functioning in cadmium absorption, which can be used to mitigate rice grain cadmium levels through hybrid breeding. Resource of indica rice genetic variation reported in this study will be valuable to geneticists and breeders., Hybrid rice cultivars are widely planted around the world. Here, the authors resequence 1,143 indica accessions, focusing on the parents of superior hybrid rice lines in China, and reveal genetic loci that are associated with heterosis via measuring frequency of parental variation difference (FPVD).

Garlic, an economically important vegetable, spice, and medicinal crop, produces highly enlarged bulbs and unique organosulfur compounds. Here, we report a chromosome-level genome assembly for garlic, with a total size of approximately 16.24 Gb, as well as the annotation of 57 561 predicted protein-coding genes, making garlic the first Allium species with a sequenced genome. Analysis of this garlic genome assembly reveals a recent burst of transposable elements, explaining the substantial expansion of the garlic genome. We examined the evolution of certain genes associated with the biosynthesis of allicin and inulin neoseries-type fructans, and provided new insights into the biosynthesis of these two compounds. Furthermore, a large-scale transcriptome was produced to characterize the expression patterns of garlic genes in different tissues and at various growth stages of enlarged bulbs. The reference genome and large-scale transcriptome data generated in this study provide valuable new resources for research on garlic biology and breeding.