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This work proposes an approach to using the non-cooperative game theory for solving finite element problems. For this, the concept of generalized Nash equilibrium is applied to finite elements implying that each element is treated as a non-cooperative “player” in a larger finite element “game”. The aim of the approach is for all players to reach a Nash equilibrium ensuring that the entire discretization is at a minimum with respect to the decision variables considered. The approach is numerically demonstrated by investigating a nonlinear elasticity problem formulated as a finite element game. It is shown that the approach matches analytical solutions in linear elasticity and is convergent to a prescribed precision for two-player nonlinear problems.

The design and fabrication of anisotropic photonic crystal supraballs with multiple responses are highly desirable for versatile environmental sensing and flexible displaying. Herein, we developed an available strategy to construct a series of multi-responsive magnetic colloidal photonic crystal (CPC) supraballs with Janus and molecular-analogue structures. Initially, the humidity and temperature sensitive CPC supraballs were obtained via immobilization of polyacrylamide (PAM) and polyisopropylacrylamide (PNIPAM) hydrogels into the CPC structure, respectively, and CdTe/ZnS quantum dots endow the supraballs fluorescent signal under UV light. Furthermore, Fe3O4 nanoparticles (NPs) were served as a magnetic hemisphere to construct CPC Janus supraballs which can be subsequently assembled into three different molecular-shaped cluster particles that integrate more response types via Fe3O4 NPs hemisphere coalescence to a magnetic coupling center, recognizing multiple responses simultaneously that correspond the environmental altering. In addition, 2D polychromatic patterns with sensitive CPC pixels printed by automatic printing system were demonstrated, which could monitor the changes of temperature and humidity. The multi-responsive magnetic controlling supraballs and 2D patterns reveal the promising applications in environmental sensing, anti-counterfeiting and displaying.

The Confinement effect is an effective strategy for enhancing the performance of catalysts during various reactions. We developed a strategy to encapsulating Palladium nanoparticles with a dopamine-derived N-doped multilayer carbon shell to catalyze the Heck reaction between iodobenzene and carbon–carbon double-bond compounds (styrene and methyl acrylate). The catalytic performances of Pd nanoparticles encapsulated within a N-doped carbon layer (Pd@N-C) and those attached to the external surface of such a layer (Pd/N-C) were evaluated and compared. Pd@N-C exhibited a lower reaction activation energy (78 kJ/mol) than that of Pd/N-C (106 kJ/mol). Thus, the activity of Pd@N-C during the Heck reaction between iodobenzene and methyl acrylate was approximately 20 times higher than that of Pd/N-C-200. The results of thermal filtration and recycling tests indicated that Pd@N-C showed a lower degree of leaching than that of Pd/N-C-200 owing to the spatial restriction effect of the cavity in the case of the former. Hence, the superior catalytic performance of Pd@N-C can be ascribed to the confinement of the Pd nanoparticles within the N-doped carbon layer. Finally, we used these catalysts to synthesize a range of para-substituted iodobenzene derivatives, thus demonstrating the potential of Pd-encapsulating catalysts for use in the Heck reaction on the technical scale.

The co-existence of Cretaceous adakitic and A-type granitoids in southern Tibet can offer fundamental constraints on subduction of the Neo-Tethyan oceanic plate and associated crustal growth processes, if their petrogenetic relationships are understood. Here, we report whole-rock geochemistry, zircon U-Pb geochronology, in situ zircon Hf isotopes and zircon trace elements from the Chanang intrusive suite, including the Zeyu and Cuojielin plutons. The Cuojielin pluton is composed of A-type quartz syenites with high K2O + Na2O, FeOT, and Zr contents and distinct negative Eu anomalies, consistent with fractional crystallization of mafic magma in a reducing, low-pressure, high-temperature environment. The adakitic Zeyu pluton, by contrast, has a strikingly high density of mafic enclaves. The elemental and isotopic signatures of the Zeyu mafic enclaves indicate a hybrid origin by mixing of magmas derived from the mantle wedge and from juvenile lower crust. The adakitic Zeyu host rocks, with low MgO, Cr, and Ni contents, show typical characteristics which originate from residual or fractionated amphibole of juvenile lower crust. The co-existence of aluminous A2-type granites and adakitic rocks indicates an anomalous high-temperature and relatively H2O-rich environment. The synchronous regional occurrence of calc-alkaline magmatism, charnockites, granulite-facies metamorphism, back-arc extension, and generation of the two studied types of Chanang intrusive rocks can best be explained in the context of an episode of rollback of the Neo-Tethyan slab in the late Cretaceous.

In this paper, a partial eigenstructure assignment problem for the high-order linear time-invariant (LTI) systems via proportional plus derivative (PD) state feedback is considered. By partitioning the open-loop system into two parts (the altered part and the unchanged part) and utilizing the solutions to the high-order generalized Sylvester equation (HGSE), complete parametric expressions of the feedback gain matrices of the closed-loop system are established. Meanwhile, a group of arbitrary parameters representing the degrees of freedom of the proposed method is provided and optimized to satisfy the stability of the system and robustness criteria. Finally, a numerical example and a three-axis dynamic flight motion simulator system example with the simulation results are offered to illustrate the effectiveness and superiority of the proposed method.

Epigenetic manipulation of a deep-sea sediment-derived Spiromastix sp. fungus using suberoylanilide hydroxamic acid (SAHA) induction resulted in the activation of a terpene-related biosynthetic gene cluster, and nine new guaiane-type sesquiterpenes, spiromaterpenes A-I (1-9), were isolated. Their structures were determined using various spectroscopic techniques, in association with the modified Mosher's method, computed electronic circular dichroism (ECD) spectra, and chemical conversion for configurational assignments. Compounds 4-6 exhibited significant effects against the NO production on lipopolysaccharide (LPS)-induced microglia cells BV2, and the preliminary SAR analyses demonstrated that a 2(R),11-diol unit is favorable. The most active 5 abolished LPS-induced NF-κB translocation from the cytosol to the nucleus in BV-2 microglial cells, accompanied by the marked reduction of the transcription levels of pro-inflammatory cytokines, including IL-1β, IL-6, and TNF-α dose-dependently in both LPS-induced BV-2 and BV-2 cells, as well as the protein and mRNA levels of iNOS and COX-2. This study complements the gap in knowledge regarding the anti-neuroinflammatory activity of guaiane-type sesquiterpenoids at the cellular level and suggests that 5 is promising for further optimization as a multifunctional agent for antineuroinflammation.

Molybdenum disulfide (MoS2) is intrinsically inert for the hydrogen evolution reaction (HER) in alkaline media due to its electronic structures. Herein, we tune the electronic structures of MoS2 by a combined strategy of post-N doping coupled with the synergistic effect of Ti3C2TX. The as-prepared N-doped MoS2/Ti3C2TX heterostructures show remarkable alkaline HER activity with an overpotential of 225 mV at 140 mA cm-2, which ranks the N-doped MoS2/Ti3C2TX heterostructures among the best MoS2/MXene-based electrocatalysts reported for alkaline HER. The first-principles calculations indicate that the N doping can enhance the activation of nearby S sites of MoS2/Ti3C2TX and thus promote the HER process. This strategy provides a promising way to develop high-efficiency MoS2/MXene heterostructure catalysts for alkaline HER.

Fermentation and chemical methods for industrial cytidine diphosphate choline (CDP-choline) catalytic production both suffer from several disadvantages such as relatively low efficiency and productivity. To overcome these problems, we applied the concept of synthetic biology to develop a new one-pot multi-enzyme system to produce CDP-choline from orotic acid. Enzymes from different sources were selected and optimized as building blocks of the system, and parameters such as oxygen supply were also optimized. This system shows a titer of 37.6 ± 1.1 mM and a reaction rate of 1.6 mM L-1 h-1, both increase 66 % from traditional processes. It also has an efficiency of energy of 25.4%, improves 2-folds. This new one-pot CDP-choline-producing system has a potential for industrial use, and the procedure to design one-pot multi-enzyme system can be applied to build other one-pot system producing energy-rich compounds.

The degradation of Ni-based superalloys in molten salts is closely related with the evolution of corrosion scales. In this work, the evolution of corrosion scales, the characteristics of the scale/alloy matrix interface associated with the corrosion mechanisms and the corrosion kinetics of a Ni-based superalloy Ni–20Cr–18W in molten salts were investigated. The outer surface of the corrosion scales was composed of numerous flakes. From the cross-sectional view, the scales gradually presented a layered structure and its formation can be ascribed to the morphology evolution of the inclusions inserted within the scales. It was found that the corrosion progress was a cooperative process involving in both oxidation and sulfuration, and the element of sulfur (S) took the precedence to penetrate into the matrix and resulted in an obvious sulfuration zone nearby the scales/alloy matrix interface. The corrosion activation energy of the investigated alloy was calculated to be 125.27 ​kJ/mol. This work is expected to work out the structural evolution of the corrosion scales and the characteristics of the scale/matrix interface associated with the corrosion mechanisms for Ni-based superalloys.

It still is a challenge to create a superior and easily coupled bifunctional electrocatalyst for water splitting impelled by a low voltage. In this work, the controlled growth of Co2P NAs on the surface of a MXene (Ti3C2Tx)-modified self-supporting electrode is demonstrated as a competent and reliable bifunctional electrocatalyst for efficient water splitting. The heterointerface in Co2P@Ti3C2Tx with an optimized adsorption free energy of H*, H2O, and better conductivity can give enhanced HER (hydrogen evolution reaction) activity, with a low overpotential (42 mV) at 10 mA cm-2. Additionally, the OER (oxygen evolution reaction) activity has also been similarly strengthened by the synergy of Co2P and MXene with an overpotential of 267 mV to arrive at 10 mA cm-2. Furthermore, the excellent bifunctional electrode (Co2P@Ti3C2Tx∥Co2P@Ti3C2Tx) exhibits efficient engineering water-splitting performance (1.46 V@10 mA cm-2) in alkaline solution. This simple design can propose a promising approach to exploit precious-metal-free catalysts for energy conversion.

The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 1015 electronvolts) indicates the existence of the so-called PeVatrons—cosmic-ray factories that accelerate particles to PeV energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays1. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref. 2). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane3–6, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators. Observations of γ-rays with energies up to 1.4 PeV find that 12 sources in the Galaxy are PeVatrons, one of which is the Crab Nebula.

Hydrogen evolution reaction (HER) is a critical process in electrocatalytic water splitting for hydrogen production. However, the development of low-cost electrocatalysts for highly efficient HER is still a huge challenge. Hence, we fabricate a multi-metal phosphide on Ni foam, FeCoNiNbxP, through a facile hydrothermal reaction followed by phosphorization. We find that Nb promotes the formation of metal phosphides, and the main phases of the catalysts with Nb are multiphase phosphides. Importantly, the Nb incorporation significantly improves the HER activity of FeCoNiP. We show that FeCoNiNb0.3P has the best HER activity, which only requires an overpotential of 78 mV to achieve a current density of 10 mA cm−2 in 1 M KOH, and demonstrates excellent stability under both constant potential and varied current densities. Our findings show that the multiple-metal compounds are beneficial to the improvement of catalytic activity and provide guidance on the design of novel catalysts for applications.

The miglitol intermediate, 6-(N-hydroxyethyl)-amino-6-deoxy-α-l-sorbofuranose (6NSL), is catalyzed from N-2-hydroxyethyl glucamine (NHEG) by resting cells of Gluconobacter oxydans. One of the key factors limiting 6NSL production was the availability of oxygen during both cell cultivation and biotransformation of NHEG to 6NSL. Based on G. oxydans/pBBR1-sldAB-pqqABCDE-tldD (G. oxydans/AB-PQQ), the Vitreoscilla hemoglobin (VHb) was heterologously expressed in G. oxydans to enhance oxygen transfer efficiency and improve 6NSL production. The recombinant G. oxydans/AB-PQQ-VHb displayed higher biomass and NHEG oxidation activity than the control stain. The transcription levels of respiratory chain-related enzyme genes in G. oxydans/AB-PQQ-VHb exhibited up-regulation, indicating that the presence of VHb promoted the respiration. The dissolved oxygen (DO) concentration for cell cultivation was optimized in a 5-L stirred bioreactor. At a DO concentration of 20%, the maximum volumetric oxidation activity of NHEG of G. oxydans/AB-PQQ-VHb in the stirred bioreactor reached 168.3 ± 3.2 U/L. Furthermore, the biotransformation of NHEG to 6NSL using G. oxydans/AB-PQQ-VHb was carried out under different oxygen tensions to investigate the effect of oxygen on 6NSL production. Finally, up to 87.5 ± 5.9 g/L 6NSL was accumulated in the reaction mixture within 16 h when the DO was controlled at 30%.

PurposeThe study aims to find potential method to enhance the stability and antioxidant activity of vitamins.Design/methodology/approachVitamin E (VE) and β-cyclodextrin (CD) were used to prepare the VE-β-CD inclusion complex via a solution method. The yielded VE-β-CD obtained from optimal experimental conditions was characterized. The mechanism of complex formation and the properties of the complex was investigated by steady-state and time-resolved fluorescence techniques. The antioxidant activity of VE-β-CD was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and compared with pure VE.FindingsThree experimental factors – reaction temperature (T), molar ratio of VE to β-CD (rm) and inclusion time (t) – were studied for the preparation of VE-β-CD. At experimental conditions of T = 60°C, rm = 1:3 and t = 3 h, a maximum inclusion rate of VE (78.62%) was obtained. The Fourier-transform infrared spectroscopy (FTIR) shows that VE molecule was physically encapsulated by β-CD in the yielded product. Subsequentially, the steady-state fluorescence intensity of VE was found to increase upon encapsulation by β-CD due to the hindrance of fluorescence quenching of VE molecules inside the hydrophobic cavity of β-CD, and an inclusion constant K was determined to equal 3.58 × 103 L/mol from the fluorescence results. The fluorescent observation was confirmed by time-resolved fluorescence experiment as the lifetime of VE increased with an increase in β-CD concentration.Originality/valueThe ability of removing radicals by VE was significantly enhanced after the formation of inclusion complex with β-CD.

In this study, the low emission combustion technology of Rich-Quench-Lean (RQL) has been applied in Trapped-Vortex Combustor (TVC), and the combinative RQL-TVC shows a promising low emissions performance. By utilizing a quench orifice plate combined with a bluff-body, a lab-scale RQL-TVC was designed. The flow fields of RQL-TVC were measured by 2-D PIV and predicted by 3-D numerical simulation. Flow structures, radial profiles of normalized mean axial velocity, turbulence intensity and mixing level of the quench zone were analyzed. Results reveal that the dual-vortex and the single-vortex flow patterns both exist in cavities and quench zone of RQL-TVC, and the turbulence intensity is strong in the quench zone with some reverse flows. The spiral vortex was discussed by 3-D streamlines and the detail flow structures of the quench zone were analyzed based on the numerical results. The mixing level of the quench zone was determined, and results show that the quench device enhances the mixing level compared with TVC. Combustion efficiency and emissions performance were investigated experimentally, and results demonstrate that RQL-TVC has relatively higher combustion efficiency and lower emission index of CO, UHC and NOx than the same size lab-scale TVC in present work.

Electrochemistry has been successfully applied in metal catalysis to avoid the usage of chemical redox agents. This strategy proved to be a powerful approach to construct carbon-carbon (C-C) and carbon-heteroatom (C-X) bonds. However, most of the developed methods are based on either anodic oxidation or cathodic reduction, in which a sacrificial reaction occurs at the counter electrode. Paired electrolysis merging with metal catalysis is underdeveloped, wherein both anodic and cathodic processes are taking place simultaneously. Herein, we demonstrated that by using esterification of carboxylic acids with aryl halides via paired electrolysis using nickel as the catalyst the respective aryl esters were obtained in good to excellent yields at room temperature in an undivided electrochemical cell.

In order to study the mechanism of excavation and supporting process of equivalent circular roadway, the model of soft roadway was established firstly. The elastoplastic solutions in excavation process were deduced based on Drucker-Prager strength criterion. Then, the elastoplastic solution under supporting condition was obtained based on homogenization method under the condition of rockbolts and liner supporting. Lastly, an example was analyzed to study the effect of different factors such as “space effect,” supporting opportunity, stresses, surrounding displacement, and the radius of plastic zone. Based on theoretical research case, the change rules of considering the “space effect” and the supporting opportunity when calculating the subarea of the roadway were discussed, the control of interval distance of rockbolts on the displacement of surrounding rock mainly reflecting in the plastic residual zone and the “space effect” in excavation, and the supporting time to control the displacement of surrounding rock not being ignored are revealed. The results can provide an important theoretical basis for the stability evaluation and quantitative support design of roadway surrounding rock. Therefore, the “space effect” and the supporting time to control the displacement and stresses of surrounding rock can not being ignored in underground engineering.

Resilience is an important indicator for measuring regional sustainable development capacity. The construction of a suitable evaluation indicator system is the premise of evaluating regional sustainable development. In this study, taking the Jiansanjiang Administration of Heilongjiang Province in China as an example, a preliminary selection library of the evaluation indicator system for the resilience of a regional agricultural soil–water resource composite system covering seven subsystems and 59 indicators was established. Selection criteria such as the Dale indicator criteria, subjective and objective combination weighting and principal component analysis were introduced to construct an optimization model for the resilience evaluation indicator system for the ASWRS. First, 14 indicators that were incomplete or incapable were removed. Then, the Dale indicator selection criteria were used to ensure that 14 indicators were selected. The binary fuzzy comparison method and criteria importance through interference correlation method were used to calculate the combination weight. Finally, an indicator system optimization model was established. The indicator system was optimized from 59 to 35 indicators, and the completeness of the indicator system reached 85.75%. The proposed method had obvious advantages in terms of indicator identification and elimination, and it may truly achieve the goal of indicator optimization. HIGHLIGHTS Resilience has become a research hotspot of agricultural soil–water engineering.; According to the Dale criteria construct a suitable evaluation indicator system.; Construction of a suitable indicator system is the key premise for measuring resilience.; Verify the rationality of the indicator system based on the combination weighting.; The model can be used as the basis to select the evaluation indicator resilience.

Plants control water-use efficiency (WUE) by regulating water loss and CO2 diffusion through stomata. Variation in stomatal control has been reported among lineages of vascular plants, thus giving rise to the possibility that different lineages may show distinct WUE dynamics in response to water stress. Here, we compared the response of gas exchange to decreasing leaf water potential among four ferns and nine seed plant species exposed to a gradually intensifying water deficit. The data collected were combined with those from 339 phylogenetically diverse species obtained from previous studies. In well-watered angiosperms, the maximum stomatal conductance was high and greater than that required for maximum WUE, but drought stress caused a rapid reduction in stomatal conductance and an increase in WUE in response to elevated concentrations of abscisic acid. However, in ferns, stomata did not open beyond the optimum point corresponding to maximum WUE and actually exhibited a steady WUE in response to dehydration. Thus, seed plants showed improved photosynthetic WUE under water stress. The ability of seed plants to increase WUE could provide them with an advantage over ferns under drought conditions, thereby presumably increasing their fitness under selection pressure by drought.

The negative photoconductivity (NPC) effect originating from the surface shell layer has been considered as an efficient approach to improve the performance of optoelectronic nanodevices. However, a scientific design and precise growth of NPC-effect-caused shell during nanowire (NW) growth process for achieving high-performance photodetectors are still lacking. In this work, GeS NWs with a controlled sulfur-rich shell, diameter, and length are successfully prepared by a simple chemical vapor deposition method. As checked by transmission electron microscopy, the thickness of the sulfur-rich shell ranges from 10.5 ± 1.5 to 13.4 ± 2.5 nm by controlling the NW growth time. The composition of the sulfur-rich shell is studied by X-ray photoelectron spectroscopy, showing the decrease of S in the GeSx shell from the surface to core. When configured into the well-known phototransistor, a featured NPC effect is observed, benefiting the high-performance photodetector with high responsivity of 105 A·W-1 and detectivity of 1012 Jones for λ = 405 nm with ultralow intensity of 0.04 mW·cm-2. However, the thicker-shell NW phototransistor shows an unstable photodetector behavior with smaller negative photocurrent because of more hole-trapping states in the thicker shell. All results suggest a careful design and controlled growth of an NPC-effect-caused shell for future optoelectronic applications.

A novel strategy for the N-arylation of NH-sulfoximines has been developed by merging nickel catalysis and electrochemistry (in an undivided cell), thereby providing a practical method for the construction of sulfoximine derivatives. Paired electrolysis is employed in this protocol, so a sacrificial anode is not required. Owing to the mild reaction conditions, excellent functional group tolerance and yield are achieved. A preliminary mechanistic study indicates that the anodic oxidation of a NiII species is crucial to promote the reductive elimination of a C-N bond from the resulting NiIII species at room temperature.

As one of the most important narrow bandgap ternary semiconductors, GaAs1−xSbx nanowires (NWs) have attracted extensive attention recently, due to the superior hole mobility and the tunable bandgap, which covers the whole near-infrared (NIR) region, for technological applications in next-generation high-performance electronics and NIR photodetection. However, it is still a challenge to the synthesis of high-quality GaAs1−xSbx NWs across the entire range of composition, resulting in the lack of correlation investigation among stoichiometry, microstructure, electronics, and NIR photodetection. Here, we demonstrate the success growth of high-quality GaAs1−xSbx NWs with full composition range by adopting a simple and low-cost surfactant-assisted solid source chemical vapor deposition method. All of the as-prepared NWs are uniform, smooth, and straight, without any phase segregation in all stoichiometric compositions. The lattice constants of each NW composition have been well correlated with the chemical stoichiometry and confirmed by high-resolution transmission electron microscopy, X-ray diffraction, and Raman spectrum. Moreover, with the increase of Sb concentration, the hole mobility of the as-fabricated field-effect-transistors and the responsivity and detectivity of the as-fabricated NIR photodetectors increase accordingly. All the results suggest a careful stoichiometric design is required for achieving optimal NW device performances.

In this paper, we study a category of restricted modules for the Ovsienko-Roger algebra, which is an extension of the Virasoro algebra of its tensor density module of degree one. We construct and characterize simple modules in this category and give natural free field realizations of certain restricted modules using the Weyl vertex algebra.

Amidst the material development for solar water splitting, silicon has been known as a promising photocatalyst candidate given its natural abundance and high processability toward future scale-up a...

Fusarium oxysporum f. sp. cucumerinum (FOC) is one of the most destructive pathogens in many cucumber-growing countries around the globe. There is still lack of high-resistant cucumber cultivars ag...

A vein structure, which becomes more pronounced with increasing ion dose, was found on the surface of polycrystalline HOPG (highly oriented pyrolytic graphite) implanted by ex situ C+ (up to 1.8 × 1017 ions/cm2), and in situ Ar+ in a transmission electron microscope (TEM). These veins are found to be independent of the crystallographic orientations and are associated with the formation of pores. Underneath the veins, a triangular-shaped core was formed with the graphite platelet inside the core displaced up towards the surface. A macro-scale ‘ruck&tuck’ geometry was thus generated at these triangle structure boundaries. Progressive movement of dislocations along basal planes during irradiation was observed, and a mechanistic model was proposed on this basis to explain the vein formation. A small increase of c-spacing was observed with irradiation but it is believed that macro-scale vein formation plays a more vital role in the dimensional and property changes in polycrystalline graphite, especially when a stress gradient is present. The model proposed also explains the change of thermal expansion in HOPG with irradiation. Together with Heggie’s ‘ruck&tuck’ and Barsoum’s ‘ripplocations’ models, the present model is considered to have provided an additional experimentally proven mechanism responsible for irradiation behaviour in graphite materials.

Phytophthora sojae can cause soybean phytophthora blight, and greatly reduce soybean production. It is helpful to understand the pathogenic mechanism of P. sojae to prevent soybean phytophthora blight and ensures food security. Glycosyl hydrolases (GHs) disintegrate plant cell walls for nutrition and invasion, and they may act as an important virulence factor during P. sojae infection. To reveal the role of GHs in the main stages of P. sojae life cycle, we measured the expression level of genes, which encoded GHs, and constructed P. sojae transformants for biological function verification by the gene editing technology CRISPR-Cas9. In this study, four genes, encoded special GH proteins, with conserved glycine-rich were identified in the P. sojae genome, and their sequences were similar to those of the TOS1 family genes. One of them, the xp_009520987.1, was named PsGRGH, and was significantly upregulated during the germination of spores and in the early infection stages. The results revealed that PsGRGH was involved in the growth and mycelial morphology regulation in P. sojae, and was essential for its sporangium development and virulence. In addition, PsGRGH is localized on the cell membrane and plays an important role in tolerance toward Bacillus and abiotic stress.

The Triassic igneous complexes in the east flank of the East Kunlun orogenic belt (E-KOB) provide a window through which to investigate the Mesozoic magmatism in the E-KOB. Here, we report the prec...

Bisphenol-A polycarbonate (PC) is an intrinsically crystallizable polymer. Its industrial parts, however, invariably remain in an amorphous state due to its extremely slow crystallization kinetics....

A good combination of strength and fracture toughness is required for aerospace applications of laser additively manufactured (LAM) AerMet100 steel. To understand the role of microstructure in the combination of strength and fracture toughness of LAM AerMet100 steel, microstructures, fracture toughness properties and corresponding crack-tip fracture behaviors of the as-deposited specimen and five types of heat-treated specimens were mainly investigated. The results indicate the as-deposited microstructure of LAM AerMet100 steel with a high amount of retained austenite has a high KIC value of ~ 81.7 MPa m1/2. After a short process of cryogenic treatment and subsequent tempering treatment, the KIC value of the steel has the lowest value of ~ 60 MPa m1/2 due to the apparent decrease of austenite and weak cracking resistance, associating with intergranular cracking along the prior austenite columnar grain boundaries and transgranular cracking of intercellular regions. In contrast, the crack-tip fracture mode of the equiaxed-grain tempered martensite microstructure of LAM AerMet100 steel becomes completely transgranular cracking with the main mechanisms of micro-void nucleation and coalescence. Homogenization treatment can apparently decrease the amount and size of large-size alloy carbides and effectively improve the fracture toughness of the steel. Furthermore, proper microstructure modification (including control of large-size carbide, grain refinement and a decrease of retained austenite) by a longer treatment process can prompt tempered LAM AerMet100 steel to achieve a good combination of yield strength (~ 1827 MPa) and fracture toughness (~ 113 MPa m1/2) compared with the wrought one.

Preparation of high-activity and earth-abundant bifunctional catalysts for efficient electrochemical water splitting are crucial and challenging. Herein, Co-doped Ni3N nanosheets loaded on nickel foam (Co-Ni3N) were synthesized. The as-prepared Co-Ni3N exhibits excellent catalytic activity toward both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) in alkaline media. Density functional theory (DFT) calculation reveals that Co-Ni3N with redistribution of electrons not only can facilitate the HER kinetics but also can regulate intermediates adsorption energies for OER. Specifically, the Co-Ni3N exhibits high efficiency and stable catalytic activity, with an overpotential of only 30 and 270 mV at a current density of 10 mA cm-2 for the HER and OER in 1 M KOH, respectively. This work provides strong evidence to the merit of Co doping to improve the innate electrochemical performance in bifunctional catalysts, which might have a common impact in many similar metal-metal nitride electrocatalysts.

In this paper, a neural network-based event-triggered fault detection scheme is addressed within the finite-frequency domain for a class of nonlinear Markov jump system. Initially, an approximation model based on multilayer neural network to alternate the nonlinear Markov jump system is constructed. For the purpose of saving the communication network bandwidth, a transmission mechanism based on the event-triggered strategy is subsequently applied in which each signal is transmitted depending on the designed condition rather than the sampling period. Further, two theorems with considering the signal frequency and the applied event-triggered mechanism are derived which guarantee the fault sensitivity as well as disturbance attenuation for the augment systems in certain frequency ranges. Then, the desired filters can be synthesized by the linear solvable conditions that are derived with the aid of the previous theorems and some novel decoupling techniques. Eventually, the proposed algorithm’s efficiency is shown by a presented computational example.

Effects of cooling rate and 0.25 at.% TiB2 addition on solidification microstructure and mechanical properties of Ti–48Al–2Cr–2Nb alloys fabricated by the investment casting with different thicknesses were studied. The results show that with the cooling rate increasing from 37 to 2×102 K/s, the solidification path of the studied alloys is unchanged. The grain size of the matrix alloy is refined from 650 to 300 μm, while the grain size of Ti–48Al– 2Cr–2Nb–TiB2 is reduced from 550 to 80 μm. The lamellar spacing of matrix alloy is reduced from 360 to 30 nm with increasing the cooling rate from 37 to 2×102 K/s, while TiB2 addition shows little refinement effect on the lamellar spacing. Ti–48Al–2Cr–2Nb–TiB2 sample under medium cooling rate (69 K/s) exhibits superior microhardness (HV 550) and ultimate tensile strength (570 MPa) among the studied alloys. The refined grain size, lamellar spacing and fine TiB2 particles could account for the favorable mechanical properties of the studied TiB2-containing alloy. The microstructure evolution was discussed in light of cooling rate, constitutional supercooling and borides addition.

A partially averaged Navier–Stokes model is used to simulate the fluid field in the coaxial cylindrical gap, and the reliability of numerical simulation is verified by comparing with the particle image velocimetry experiment. Firstly, the influence of structural parameters and physical parameters on heat transfer enhancement of the slit model is investigated. In the next step, response surface method is adopted to obtain the slit parameter structure with optimal heat transfer performance. Slit width (2.5 mm

Two new species of steganacarid mites (Oribatida, Phthiracaroidea, Steganacaridae), Atropacarus (Hoplophorella) bacillisetus sp. nov. from Hainan Province and Atropacarus (Hoplophorella) longicarin...

Bacterial spot, which is caused by several Xanthomonas species, is an economically important disease in tomato (Solanum lycopersicum). Great efforts have been made for the identification of resistant sources and the genetic analysis of resistance. However, the development of resistant commercial varieties is slow due to the existence of multiple species of the pathogen and a poor understanding of the resistance mechanism in tomato. The current study revealed that the Rx4 gene encodes a nucleotide-binding leucine-rich repeat protein in the wild tomato species Solanum pimpinellifolium and specifically recognizes and confers a hypersensitive response (HR) to Xanthomonas euvesicatoria pv. perforans race T3 expressing the AvrXv3 avirulence protein. Complementation of the Rx4 gene in the susceptible tomato line Ohio 88119 using a transgenic approach resulted in HR, whereas knockout of the gene through CRISPR/Cas9 editing in resistant lines Hawaii 7981 and PI 128216 led to non-HR to race T3. Transcription of Rx4 was not induced by the presence of race T3. Furthermore, the Rx4 protein did not show physical interaction with AvrXv3 but interacted with SGT1-1 and RAR1. Virus-induced gene silencing of SGT1-1 and RAR1 in the resistant line PI128216 suppressed the HR to race T3. Taken together, our study confirms Rx4 is the gene conferring the HR to bacterial spot race T3 and reveals the potential roles of SGT1-1 and RAR1 as signals in the Rx4-mediated HR. This discovery represents a step forward in our understanding of the mechanism of resistance to bacterial spot in tomato and may have important implications for understanding plant-bacterial interactions.

Developing highly efficient non-precious electrocatalytic materials for H2 production in an alkaline medium is attractive on the front of green energy production. Herein, we successfully designed an electrocatalyst with superb hydrophilicity, high conductivity, and a kinetically beneficial structure using Ni2P/MXene over a 3D Ni foam (NF) for the alkaline hydrogen evolution reaction (HER) based on the laboratory and computational research works. The designed self-supported and highly effective electrocatalyst achieves a huge boost in the HER activity compared with that of pristine Ni2P nanosheets owing to the distinctive structure and synergy of coupling Ti3C2Tx and Ni2P. More specifically, Ni2P/Ti3C2Tx/NF produces an electric current density of 10 mA·cm-2 under a low overpotential (135 mV) and shows excellent durability under alkaline (1 M KOH) conditions, and the observed performance degradation is negligible. The outstanding HER activity makes the synthetic strategy of Ni2P/Ti3C2Tx/NF a potential approach to be extended to other transition-metal-based electrocatalysts for enhanced catalytic performance.

The exploration of nonlinear optical (NLO) materials with a large NLO response promotes a diverse range of photonic applications. With excellent optoelectronics property, perovskite semiconductors ...

Rational design of efficient, low-cost, and durable electrocatalysts for the hydrogen evolution reaction (HER) in various pH media is highly desirable but remains challenging. Herein, for the first time, we present a novel hybrid of ruthenium diphosphide encapsulated in P-doped porous carbon (denoted as RuP2@PC) utilizing metal–organic frameworks (MOFs) as templates by a multi-step strategy. Unexpectedly, benefitting from the synergistic contribution of highly dispersed ultrafine RuP2 nanoparticles, porous carbon skeleton, and P-dopant, the as-synthesized RuP2@PC exhibits exceptional catalytic activity and superior durability as pH-universal electrocatalysts for the HER. Particularly, a low overpotential of 78.9 mV to deliver a current density of 10 mA cm−2 and a small Tafel slope of 36.7 mV dec−1 can be achieved in 1.0 M KOH toward the HER. Such outstanding electrocatalytic properties exceed those of commercial Pt/C and rank the catalyst among the best HER electrocatalysts reported until now. Importantly, this work paves a new route in elaborately fabricating efficient and stable electrocatalysts based on MOFs for energy-related fields.

Spacecraft materials are a key limiting factor for the rapid development of the aerospace exploration field. In an advanced spacecraft, superior multi-functional material with thermal management and electromagnetic shielding can ensure the normal operation of its equipment in space. Currently, graphene thin film can’t satisfy a high heat flux and excellent through-plane thermal conduction. In this contribution, a full-carbon dual-functional graphene/carbon nanotubes (CNTs) thick film with high heat flux was successfully prepared, and the structure and composition evolution was investigated after hot-pressing carbonization and graphitization of 2800 °C, which indicates the existence of a compact defects-free and high crystalline carbon structure. Molecular dynamics simulations further confirm the formation of C–C covalent bonds between graphene sheets and CNTs after 2800 °C graphitization, enhancing the phonons transfer in through-plane. Simultaneously, the axially adjacent graphene sheets are connected by the CNTs, which endow excellent thermal conductive properties. The in-plane and through-plane thermal diffusivity are as high as 1188.2 mm2/s and 8.0 mm2/s, respectively. Moreover, the electrical conductivity up to 1819.17 S/cm and EMI SE reach 75 dB in Ku-band. The results provide a bright prospect for spacecraft materials preparation and application.

When quantum dots are used as fluorescent probes or drug tracers for in vivo imaging, the quantum dots in the blood will come into direct contact with vascular endothelial cells. Thus, it is necessary to study whether quantum dots can affect endothelial function after being injected into blood vessels as imaging agents. In recent years, there have been numerous studies on the toxicity of quantum dots. Herein, we focused on five types of quantum dots (Cd-containing quantum dots, CuInS2 quantum dots, black phosphorus quantum dots, MXene quantum dots, and carbon-based quantum dots) for cell imaging and their toxicity in vivo and in vitro. Although current research on the toxicity of quantum dots has not reached a consistent conclusion, it can guide the next step in evaluating their cytotoxicity.

Controlling the products, i.e. achieving high selectivity, is essential yet challenging for many chemical processes. So far, ex/in situ methods have been reported to prepare selective catalysts; here, we present a distinct operational strategy. To demonstrate its power and simplicity, a high-pressure artificial photosynthetic device (HiPAD) was designed correspondingly to achieve selective and efficient solar-driven photoelectrochemical (PEC) carbon dioxide reduction (CO2R). The HiPAD features a high-pressure operation to enhance the CO2 concentration, as well as straight operations of copper (Cu) catalyst synthesis and Cu-catalyzed PEC CO2R to enhance the active site concentration. This strategy is quantitatively described by the Langmuir mechanism. By leveraging it, CO2R selectivity higher than 80% and solar-to-chemical energy conversion efficiency exceeding 0.9% were experimentally demonstrated. The material and synthesis versatility feature of this strategy was also demonstrated. These results shed new light on selective and efficient catalytic conversions.

Almost all salt forms of nucleotides exist as crystalline hydrates. In this study, the hydrates of adenosine-3′,5′-cyclic phosphate sodium (cAMPNa·nH2O, n = 2, 4, 5, including its methanol solvate of n = 3) were systematically investigated for the crystal structures, their humidity sensibility, the transformation behaviors mediated by humidity, and the relationship between crystal water behaviors and specific structures. It was found that there are some major differences in crystal morphologies, molecular conformation, bonding profiles, and crystal water distribution in the lattices of different hydrates. The difference in the desorption dynamics of crystal water for the different hydrates was mainly attributed to their steric effects in the crystal lattice despite the relation to the interaction of water molecules with sodium ions and cAMP anions. The reversible conversions between the hydrates and their corresponding low hydrates or even anhydrates occur along with desorption/uptake of crystal water mediated by humidity, yet the reversible transformation capability would be disabled once the host structures were destroyed due to excessive loss of crystal water.

Cobalt oxyhydroxide (CoOOH) has attracted great attention in electrochemical water splitting. However, the mechanism behind its catalytic performance and how to improve its activity are still under debate. In the work, we propose that strain engineering is an effective and simple way to achieve the purpose. Based on density functional theory (DFT), we investigate the effects of strain engineering on the electronic structure and catalytic performance of two-dimensional (2D) CoOOH and the underlying mechanism of the oxygen evolution reaction (OER). We find that strain engineering is effective to tailor the electronic configuration of Co3+ ions in CoOOH, which can be transferred from low spin (LS: t62ge0g) to high spin (HS: t42ge2g) at a tension of 9%. Importantly, we show that LS CoOOH is a poor OER catalyst, because it is ineffective for O2 release with a large energy (1.35 eV). However, HS CoOOH is much more active in the OER because of smaller O2 release energy (0.03 eV) and more effective O–O bond coupling (1.21 eV) in the intramolecular oxygen coupling mechanism. The overpotential for LS CoOOH is 0.66 V according to the hydroxide ion attack mechanism, while the direct intramolecular coupling is hard to occur. HS CoOOH shows low overpotentials, 0.32 and 0.5 V, for the intramolecular coupling and hydroxide ion attack, respectively, which are comparable to those of the best OER catalysts (0.25 to 0.4 V). Our work demonstrates that the spin state transition of Co3+ ions tuned by strain engineering is an effective way to improve the OER activity of 2D CoOOH.

It is very interesting and challenging to investigate the electronic structures of diatomic dications, due to the nature of coulombic repulsive and bound attractive dissociation limits and their avoided diabatic interactions. Using the multi-reference configuration interaction approach, comprehensive ab initio calculations of the first 36 electronic states, corresponding to 15 dissociation limits, of dication HF2+ are reported. Good agreements for the vertical excitation energies and dissociation limits are achieved with the available references. Besides the common interesting quantities as adiabatic potential energy curves, dipole moments and spectral constants for the bound states, the nonadiabatic radial coupling matrix elements for the 1,3Π states are also presented. A showcase for the diabatic potentials of 3Π states are presented and discussed. Furthermore, predissociation states from the nonadiabatic couplings or avoided crossing of potential energy curves, known as shape resonances in collisions, are also investigated by using the WKB and scattering methods.

With increasing pathogenic bacterial infection that is occurring worldwide, antibacterial therapy has become an important research field. There is great antimicrobial potential in the nanomaterial-based metal–organic framework (MOF) platform because it is highly biocompatible, biodegradable, and nontoxic, and it is now widely used in the anticancer agent industry and in the production of medical products. This review summarizes the possible mechanisms of representative MOF-based nanomaterials, and recounts recent progress in the design and development of MOF-based antibacterial materials for the remedy of postoperative infection. The existing shortcomings and future perspectives of the rapidly growing field of antimicrobial therapy addressing patient quality of life issues are also briefly discussed. Because of their wide applicability, further studies on the use of different MOF antimicrobial therapies will be of great interest.

Rechargeable aprotic alkali metal (Li and Na)–iodine (AM–I2) batteries with high theoretical capacity and specific energy density have emerged as one of the promising energy storage technologies. However, their application has been severely limited by dendrite formation on alkali metal anodes. By infusing a eutectic Li–Na alloy into a carbon cloth (CC), we developed a novel bifunctional Li–Na alloy-CC anode for Li/Na–iodine batteries with significantly enhanced electrochemical performance. Specifically, the LiNa-CC anode in a symmetric battery exhibited an ultra-stable cycling stability up to 800 and 1650 hours for Li and Na plating/stripping at a current density of 40 and 20 mA cm−2, respectively. When coupled with an iodine cathode in a Li/Na–iodine battery, the LiNa-CC anode exhibited a significantly improved cycling stability with 84.8% and 83.3% capacity retentions after 2000 cycles at a current density of 5C for Li–I2 and Na–I2 batteries, respectively. This work provides new perspectives for developing multifunctional dendrite-free alkali metal–iodine batteries.

Driving fatigue is often an important cause of traffic accidents. Monitoring psychological parameters of driver to detect fatigue state is an effective approach to prevent traffic accident. In order to study driving fatigue state in low-voltage and hypoxia plateau environment, the research involved the aspects of subjective monitoring and objective monitoring by driver's real-time electroencephalogram (EEG) signal which was obtained by field driving fatigue test. Nonlinear and linear methods were used to analyze EEG signal in awake, critical, and fatigue three typical states. The EEGLAB in the MATLAB toolbox was used in nonlinear method to analyze the power spectral density map of θ, α, β wave in three typical states. The new EEG eigenvalues were collected, and the EEG power characteristic values were calculated to evaluate the trend of EEG signal in linear method. Combined nonlinear and linear methods with subjective data analysis, the energy characteristic of (α + θ)/β and (α + β)/θ were recommended as the indicator to evaluate driving fatigue characteristics in low-voltage and hypoxia plateau environment. This study provided foundation of theory and examination for the design of driving fatigue warning device in low-voltage and hypoxia plateau environment, which is of great significance for the development of driver fatigue detection system.

As a part of Comprehensive Research Facility for Fusion Technology (CRAFT) project, a large superconducting linear plasma testing facility will be built to evaluate candidate plasma-facing materials and component mockups for China Fusion Engineering Test Reactor (CFETR). Powerful plasma source is a key component to produce reactor-relevant particle flux for material irradiation purpose. To develop source technology, a new testing platform is built at the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). This platform utilizes conventional water-cooled magnets to sustain a steady-state field strength of > 7000 G and is equipped with a pump train of 4500 m3h− 1, making it capable to evaluate various plasma sources with a fueling rate up to several standard liter per minute (SLM). The ion flux can be measured with a water-cooled target probe. At present, intense plasma beam with an ion flux of > 1023 m− 2 s− 1 has been achieved with a cascaded arc source in this platform. Further testing on the lifetime of source components is ongoing. New cascaded arc type sources based on non-cylinder plasma column concept has been proposed to increase irradiation area and will be tested as well. After finishing source R&D mission, this platform will be upgraded into a plasma-material interaction research facility and open to all researchers in the community.

Truffles are included among the most expensive fungi around the world. Around 180 truffle species have been described worldwide, and more than 50 species have been recorded from China. However, so far, the influence of provenances on truffle morphology, phylogeny, and bacterial and fungal microbiome community structure of both peridium and gleba has been scarcely studied. The rare excavated Chinese truffle Tuber pseudobrumale, known previously only from its type collection, was investigated in different collections from Yunnan and Sichuan provinces located in southwestern China. The microbiome showed differences at the phylum and order levels according to their provenances and compartments (gleba or peridium). For the first time, yeasts and filamentous fungi associated with truffles were studied using a metagenomic approach. Sixty-one fungal genera were identified by Illumina high throughput sequencing, belonging to 48 families, 37 orders, 20 classes, and 11 phyla were recorded. The non-metric multi-dimensional scaling plots (NDMS) showed different patterns for bacteria and fungi. In bacteria, both compartments and provenances were grouped in different clusters, while fungi grouped together more by provenance than by compartments. These changes were recorded along with macro- and micromorphological variations of the ascomata in the different collections. This integral study demonstrates for the first time that the provenances originate conspicuous intraspecific variations in T. pseudobrumale in terms of morphology and microbiome community structure in peridium and gleba, despite strong genetic consistency.