A built‐in electric field in electrocatalyst can significantly accumulate higher concentration of NO3− ions near electrocatalyst surface region, thus facilitating mass transfer for efficient nitrate ...removal at ultra‐low concentration and electroreduction reaction (NO3RR). A model electrocatalyst is created by stacking CuCl (111) and rutile TiO2 (110) layers together, in which a built‐in electric field induced from the electron transfer from TiO2 to CuCl (CuCl_BEF) is successfully formed . This built‐in electric field effectively triggers interfacial accumulation of NO3− ions around the electrocatalyst. The electric field also raises the energy of key reaction intermediate *NO to lower the energy barrier of the rate determining step. A NH3 product selectivity of 98.6 %, a low NO2− production of <0.6 %, and mass‐specific ammonia production rate of 64.4 h−1 is achieved, which are all the best among studies reported at 100 mg L−1 of nitrate concentration to date.
An electrocatalyst is created by stacking CuCl (111) and rutile TiO2 (110) layers together. A built‐in electric field induced from the electron transfer from TiO2 to CuCl (CuCl_BEF) is thus formed, which triggers interfacial accumulation of NO3− ions around the electrocatalyst. A NH3 product selectivity of 98.6 %, a low NO2− production of <0.6 %, and mass‐specific ammonia production rate of 64.4 h−1 is achieved.
Nitrate electrocatalytic reduction (NO3RR) for ammonia production is a promising strategy to close the N‐cycle from nitration contamination, as well as an alternative to the Haber–Bosch process with ...less energy consumption and carbon dioxide release. However, current long‐term stability of NO3RR catalysts is usually tens of hours, far from the requirements for industrialization. Here, symmetry‐broken Cusingle‐atom catalysts are designed, and the catalytic activity is retained after operation for more than 2000 h, while an average ammonia production rate of 27.84 mg h−1 cm−2 at an industrial level current density of 366 mA cm−2 is achieved, obtaining a good balance between catalytic activity and long‐term stability. Coordination symmetry breaking is achieved by embedding one Cu atom in graphene nanosheets with two N and two O atoms in the cis‐configuration, effectively lowering the coordination symmetry, rendering the active site more polar, and accumulating more NO3− near the electrocatalyst surface. Additionally, the cis‐coordination splits the Cu 3d orbitals, which generates an orbital‐symmetry‐matched π‐complex of the key intermediate *ONH and reduces the energy barrier, compared with the σ‐complex generated with other catalysts. These results reveal the critical role of coordination symmetry in single‐atom catalysts, prompting the design of more coordination‐symmetry‐broken electrocatalysts toward possible industrialization.
A coordination‐symmetry‐breaking Cusingle‐atom catalyst enables a good balance between catalytic activity and long‐term stability in nitrate electroreduction to ammonia. The catalytic activity is retained after operation for more than 2000 h, while an average ammonia production rate of 27.84 mg h−1 cm−2 at an industrial level current density of 366 mA cm−2 is achieved.
A
bstract
We investigate the heavy-light four-point function up to double-stress-tensor, supplementing 1910.06357. By using the OPE coefficients of lowest-twist double-stress- tensor in the ...literature, we find the Regge behavior for lowest-twist double-stress-tensor in general even dimension within the large impact parameter regime. In the next, we perform the Lorentzian inversion formula to obtain both the OPE coefficients and anomalous dimensions of double-twist operators
O
H
O
L
n,J
with finite spin
J
in
d
= 4. We also extract the anomalous dimensions of double-twist operators with finite spin in general dimension, which allows us to address the cases that ∆
L
is specified to the poles in lowest-twist double-stress-tensors where certain double-trace operators
O
L
O
L
n,J
mix with lowest-twist double-stress-tensors. In particular, we verify and discuss the Residue relation that deter- mines the product of the mixed anomalous dimension and the mixed OPE. We also present the double-trace and mixed OPE coefficients associated with ∆
L
poles in
d
= 6
,
8. In the end, we turn to discuss CFT
2
, we verify the uniqueness of double-stress-tensor that is consistent with Virasoso symmetry.
We consider Einstein-Horndeski gravity with a negative bare constant as a holographic model to investigate whether a scale invariant quantum field theory can exist without the full conformal ...invariance. Einstein-Horndeski gravity can admit two different AdS vacua. One is conformal, and the holographic two-point functions of the boundary energy-momentum tensor are the same as the ones obtained in Einstein gravity. The other AdS vacuum, which arises at some critical point of the coupling constants, preserves the scale invariance but not the special conformal invariance due to the logarithmic radial dependence of the Horndeski scalar. In addition to the transverse and traceless graviton modes, the theory admits an additional trace/scalar mode in the scale invariant vacuum. We obtain the two-point functions of the corresponding boundary operators. We find that the trace/scalar mode gives rise to an non-vanishing two-point function, which distinguishes the scale invariant theory from the conformal theory. The two-point function vanishes in
d
=
2
, where the full conformal symmetry is restored. Our results indicate the strongly coupled scale invariant unitary quantum field theory may exist in
d
≥
3
without the full conformal symmetry. The operator that is dual to the bulk trace/scalar mode however violates the dominant energy condition.
The exploration of extreme environments has become necessary for understanding and changing nature. However, the development of functional materials suitable for extreme conditions is still ...insufficient. Herein, a kind of nacre‐inspired bacterial cellulose (BC)/synthetic mica (S‐Mica) nanopaper with excellent mechanical and electrical insulating properties that has excellent tolerance to extreme conditions is reported. Benefited from the nacre‐inspired structure and the 3D network of BC, the nanopaper exhibits excellent mechanical properties, including high tensile strength (375 MPa), outstanding foldability, and bending fatigue resistance. In addition, S‐Mica arranged in layers endows the nanopaper with remarkable dielectric strength (145.7 kV mm−1) and ultralong corona resistance life. Moreover, the nanopaper is highly resistant to alternating high and low temperatures, UV light, and atomic oxygen, making it an ideal candidate for extreme environment‐resistant materials.
A nacre‐inspired nanopaper is fabricated through an aerosol‐assisted biosynthesis (AABS) strategy. Based on the AABS strategy and biomimetic structure design, the nanopaper has excellent mechanical properties, high dielectric strength, and ultralong corona resistance time. The dielectric‐mechanical comprehensive performance of the nanopaper is far beyond that of various commercial mica papers.
A high-power monolithic continuous wave (CW) Yb doped fiber amplifier at 1064 nm has been demonstrated based on traditional large mode area step-index fiber, which generated 5.07 kW narrow line-width ...laser with near diffraction-limited beam quality. At the maximal output power, >35dB OSNR has been achieved with line-width being 370pm, and the measured beam quality is M 2 x = 1.252, M 2 y = 1.322. The influence of cooling temperature on SRS has been investigated in high power fiber lasers, which shows that the SRS at 4kW has been suppressed 24 dB by lowering the temperature from 20°C to 8°C. To the best of our knowledge, this is the highest narrow line-width laser power generated from the traditional large mode area step-index monolithic fiber amplifier.
Abstract
Segmented and cluster fracturing can improve the efficiency of volume stimulation in shale reservoirs and reduce construction costs. It is important to clarify the propagation ...characteristics of hydraulic fractures and stress interference under different fracturing techniques to optimize the process of clustered and staged fracturing. For this purpose, we have developed a 2D XFEM-based CZM hydraulic fracturing model. The capability of this model was validated by analytical solutions and then used to study the propagation paths of hydraulic fractures and the characteristics of stress interference under simultaneous fracturing, sequential fracturing, zipper fracturing and multi-cluster fracturing. The results show that in simultaneous fracturing, the middle cluster is compressed by the external position clusters, and the opening width of hydraulic fractures is reduced. In sequential fracturing, the fracture that first initiates create an additional stress field that inhibits the propagation distance of subsequent fractures and the propagation path of hydraulic fractures is also affected in the stress shadow region. Zipper fracturing can effectively alleviate stress interference between multiple fractures, and internal fractures can also propagate a certain distance. In multi-cluster fracturing, the fluid rate into the internal fractures may be limited, and fracture propagation is also limited by stress interference. Therefore, it is necessary to optimize the parameters of clusters to ensure that all clusters can initiate fractures normally. The research results are important for the parameter optimization of clustered and staged fracturing, especially for well factory fracturing mode.
Three-generation MSW effect in curved spacetime is studied and a brief discussion on the gravitational correction to the neutrino self-energy is given. The modified mixing parameters and ...corresponding conversion probabilities of neutrinos after traveling through celestial objects of constant densities are obtained. The method to distinguish between the normal hierarchy and inverted hierarchy is discussed in this framework. Due to the gravitational redshift of energy, in some extreme situations, the resonance energy of neutrinos might be shifted noticeably and the gravitational effect on the self-energy of neutrino becomes significant at the vicinities of spacetime singularities.
Summary
Interleukin 17A (IL‐17A) is implicated in the pathogenesis of several neuroimmunologic diseases. We aimed to evaluate the relationship between IL‐17A and seizure severity in patients with ...epilepsy. Seventy patients with probable symptomatic epilepsy and 68 healthy controls were included. Interictal serum IL‐17A and related cytokine (IL‐23, IL‐6, IL‐1β, interferon gamma (IFN‐γ), and IL‐10) levels were measured. The relationship between seizure severity and cytokine concentrations was assessed by Spearman correlation and multivariate linear regression test. IL‐17A levels in the cerebrospinal fluid (CSF) were tested in 30 additional patients with epilepsy, either in the postictal or interictal period and 15 patients with idiopathic inflammatory demyelinating diseases (IIDDs). Interictal serum IL‐17A levels were significantly elevated in patients with epilepsy compared to controls. IL‐6, IFN‐γ, and IL‐1β levels were also markedly elevated. Spearman correlation analysis revealed positive correlation between IL‐17A, IL‐6 levels and Veterans Administration Seizures Frequency and Severity Rating Scale score(VA score); IFN‐γ, IL‐10 levels, and National Hospital Seizure Severity Scale (NHS3) score. In addition, IL‐17A levels correlated significantly with seizure frequency. Multivariate linear regression test showed that only IL‐17A levels were independently positively correlated with VA scores (B = 0.288, p = 0.027). Postictal IL‐17A levels in the CSF were significantly elevated compared to interictal patients and patients with IIDDs. Our results suggest that interictal IL‐17A levels correlated highly with seizure severity.
Tobacco bacterial wilt (TBW) and tobacco black shank (TBS) are two of the most devastating tobacco soil-borne diseases worldwide. In this study, Pseudomonas aeruginosa NXHG29 exhibited dually ...antagonistic activities against TBW and TBS in vitro assays. Pot experiments were performed to evaluate the capability of a novel bio-organic fertilizer (BOF) consisting of organic fertilizer with NXHG29 to control TBW and TBS. The results showed that application of BOF could more effectively decrease the disease incidence of TBW and TBS than the direct application of NXHG29. Higher amounts of BOF application (0.5% and 1% amendment) resulted in the more suppressive effects on tested pathogens when compared with a low amount of BOF application (0.1% amendment). To determine the antagonistic mechanism of NXHG29, we investigated the colonization pattern of NXHG29 on tobacco roots in a sand system and a natural soil system by tagging NXHG29 with a GFP-marked plasmid. Similar observations were obtained in the two systems. The results indicated that GFP-tagged NXHG29 colonized first the differentiation zones followed by the elongation and maturation zones of the primary roots and subsequently around the junctions of primary and lateral roots. The population dynamics of GFP-tagged NXHG29 on tobacco roots and in the rhizosphere were also monitored. The development of the BOF using dually antagonistic bacteria might provide new options for control strategies, especially with respect to managing both diseases simultaneously in the host plant, which should be more effective in the long term.
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