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Catalytic reduction of NO by material surface attracts growing interests due to its promising applications in air purification. Here, the adsorption and dissociation behaviors of single NO molecule on the Be(0001) surface were systematically investigated using first-principles calculations. Through potential energy surface calculations, we found that NO molecule can adsorb on the surface without any energy barrier along the vertical channels with N end-on orientation, among which adsorption on the hcp hollow site of the Be(0001) surface is the most energetically favorable. Moreover, the dissociation of NO molecule along the fcc hollow channel was investigated, and it was found that the dissociation process of NO is an activated type with an energy barrier of 0.34 eV, indicating that the reduction of NO on the Be(0001) surface is energetically probable. The electronic structure analyzing of the most stable chemisorption state that locates on the hcp site, along with the sizeable charge redistribution, reveals that the chemisorption of NO on the Be(0001) surface is dominated by the interaction between the molecular orbital 2 π ∗ of NO molecule and electronic state p of surface Be atom. [ABSTRACT FROM AUTHOR]

First-principles calculations based on the density functional theory were performed to systematically study the electronic properties of the thin film of antimony in (111) orientation. By considering the spinâ€"orbit interaction, for stoichiometric surface, the topological states keep robust for six-bilayer case, and can be recovered in the three-bilayer film, which are guaranteed by time-reversal symmetry and inverse symmetry. For reduced surface doped by non-magnetic Bi or magnetic Mn atom, localized three-fold symmetric features can be identified. Moreover, band structures show that the non-trivial topological states stand for non-magnetic substitutional Bi atom, while can be eliminated by adsorbed or substitutional magnetic Mn atom. [ABSTRACT FROM AUTHOR]

It is an open question to learn an over-complete dictionary from a limited number of face samples, and the inherent attributes of the samples are underutilized. Besides, the recognition performance may be adversely affected by the noise (and outliers), and the strict binary label based linear classifier is not appropriate for face recognition. To solve above problems, we propose a virtual samples based robust block-diagonal dictionary learning for face recognition. In the proposed model, the original samples and virtual samples are combined to solve the small sample size problem, and both the structure constraint and the low rank constraint are exploited to preserve the intrinsic attributes of the samples. In addition, the fidelity term can effectively reduce negative effects of noise (and outliers), and the ε -dragging is utilized to promote the performance of the linear classifier. Finally, extensive experiments are conducted in comparison with many state-of-the-art methods on benchmark face datasets, and experimental results demonstrate the efficacy of the proposed method. [ABSTRACT FROM AUTHOR]

Study of the native defects in transition metal dichalcogenides (TMDCs) is of fundamental interest and potential technological importance. The atomic and electronic structures of native defects with charge states in ZrSe 2 are systematically investigated for the first time based on first-principles calculations with the optB86R-vdW and HSE06 functionals. We identify the configurations of relatively stable defects including Zr interstitial (Zr int), Se vacancy (V Se) and Zr antisite (Zr Se). The positive charged Zr interstitial defect (Zr int 2 +) has the lowest formation energy and thus is most commonly seen in ZrSe 2 , which is in good agreement with experimental observation. The Zr Se defect is found to form a DX-like configuration. Moreover, the non-interacting Zr Frenkel pairs are the most favorable form of intrinsic defects. The electronic structure analyses of these defects reveal that the extra Zr atoms adjacent to the defects act as donors, which are responsible for the native n-type conductivity of as-grown ZrSe 2. Our study can provide an insight into understanding the properties of native defects in ZrSe 2. • Native defects in ZrSe 2 are investigated for the first time by taking into account both the vdW and HSE06 functionals. • The atomic and electronic structures of native defects are discussed in detail. • Our results show that the native defects dominate the n-type doping of ZrSe 2. [ABSTRACT FROM AUTHOR]

• The adsorption configuration of water dimer on the α -Pu 2 O 3 (111) surface is identified by first-principles calculations. • The dissociations of water clusters on the α -Pu 2 O 3 (111) surface are investigated by ab-initial molecular dynamics simulation. • The hydrogen-bonding interaction within the clusters and hydrogen-transfer reaction facilitate the dissociation process of water dimer and trimer. Study of the water-plutonium oxide interaction is of fundamental importance in the corrosion of plutonium materials. In the present work, we report the results of adsorption and dissociation of water molecules on the α -Pu 2 O 3 (111) surface with ab-initio molecular dynamics (AIMD) simulations. We identify the stable adsorption configuration of water dimer on the α -Pu 2 O 3 (111) surface. Also, we find that one water molecule in the dimer can dissociate into hydrogen atom and hydroxyl group, and the reaction energy barrier is calculated to be 0.21 eV using climbing image nudged elastic band (CINEB) method. Electronic structure analysis shows a strong interaction between the dissociated hydrogen atom and the surface oxygen atom. Moreover, AIMD simulations at 300K and 600K confirm that the hydrogen-bonding interaction within the water clusters including dimer and trimer, as well as the hydrogen-transfer reaction, facilitates the dissociation of water clusters on the α -Pu 2 O 3 (111) surface. The obtained results can provide a way to understand the corrosion of plutonium enhanced by moisture. [ABSTRACT FROM AUTHOR]

Heterogeneous reactions of toluene/NO 2 with and without O 3 on α-Fe 2 O 3 particles was studied as a function of temperature by using in situ diffuse reflectance infrared Fourier transform spectrometry (DRIFTS). The results show that the formation of R-ONO 2 group is identified on the α-Fe 2 O 3 particles surface, indicating the formation of benzyl nitrate in the presence of toluene/NO 2 with or without O 3 at different temperatures from 253 K to 298 K. From the analysis of the spectral changes, the reaction kinetics, such as reaction rate and uptake coefficient are sensitive to temperature. During the heterogeneous reaction of toluene/NO 2 , the formation rate of organic nitrate increases from (2.38 ± 0.07) × 1017 ions g−1 s−1 to (5.95 ± 0.09) × 1017 ions g−1 s−1 when the temperature decreases from 278 K to 253 K. When the trace gases were toluene/NO 2 /O 3 , the reaction rate increases about 3 folds with the increasing of temperature from 253 K to 298 K. In the absence of ozone, nitrification from heterogeneous reaction is exothermic process. However, the addition of ozone dominates the whole reaction process, resulting the different change trends of formation rate at similar range of temperatures. Furthermore, reactive uptake coefficient increases from (6.73 ± 0.02) × 10−7 to (1.64 ± 0.05) × 10−6 with decreasing temperature from 278 K to 253 K during the heterogeneous reaction of toluene/NO 2 on α-Fe 2 O 3 particles. The values of activation energy for the heterogeneous reaction of toluene/NO 2 and toluene/NO 2 /O 3 are determined to be −8.60 ± 0.91 kJ mol−1 and 15.14 ± 2.51 kJ mol−1, respectively. It implies that the heat change is an important factor in affecting the heterogeneous reaction under the seasonal temperature changes. [Display omitted] • Heterogeneous reaction kinetics was studied for NOCs formation with changes of temperature. • Low temperature promotes the heterogeneous reaction of toluene/NO 2. • Oxidation of O 3 dominates the heterogeneous reaction of toluene/NO 2 at high temperature. • The values of activation energy play a key role in the formation processes of NOCs in atmosphere environment. [ABSTRACT FROM AUTHOR]

Inorganic lead halide perovskite is one of the most excellent fluorescent materials, and it plays an essential role in high-definition display and visible light communication (VLC). Its photochromic properties and stability determine the final performance of light-emitting devices. However, efficiently synthesizing perovskite with high quality and stability remains a significant challenge. Here, we develop a facile and environmentally friendly method for preparing high-stability and strong-emission CsPbBr3/Cs4PbBr6 composites using ultrasonication and liquid paraffin. Tuning the contents of liquid paraffin, bright-emission CsPbBr3/Cs4PbBr6 composite powders with a maximum PLQY of 74% were achieved. Thanks to the protection of the Cs4PbBr6 matrix and liquid paraffin, the photostability, thermostability, and polar solvent stability of CsPbBr3/Cs4PbBr6-LP are significantly improved compared to CsPbBr3 quantum dots and CsPbBr3/Cs4PbBr6 composites that were prepared without liquid paraffin. Moreover, the fabricated CsPbBr3/Cs4PbBr6-LP-based WLEDs show excellent luminescent performance with a power efficiency of 129.5 lm/W and a wide color gamut, with 121% of the NTSC and 94% of the Rec. 2020, demonstrating a promising candidate for displays. In addition, the CsPbBr3/Cs4PbBr6-LP-based WLEDs were also demonstrated in a VLC system. The results suggested the great potential of these high-performance WLEDs as an excitation light source to achieve VLC. [ABSTRACT FROM AUTHOR]

[Display omitted] • Best modification effect is achieved by titanate coupling agent M3. • Activation index and oil absorption value of modified nanoparticles are improved. • FT-IR analysis showed that the coupling agent was attached to the nanoparticles. • Modification of nanoparticles improved the quality of the micro-nano green tape. Nanoparticles are widely used for the fabrication of advanced ceramics. Unfortunately, nanoparticles tend to agglomerate when added to ceramic slurries for tape casting. In this study, the surface modification process of alumina nanoparticles was studied. Coupling agents were introduced to modify the surface of alumina nanoparticles to prevent their agglomeration in ceramic slurry during tape casting. The effects of variation in the modifier dosage, modification temperature, and modification time on the activation index and oil absorption value of modified alumina nanoparticles were investigated. The influence of the modification process on microstructure and properties of the micro-nano green tapes was also investigated. Experimental results showed that the best modification effect was achieved via modification of the alumina nanoparticles with 2.5 wt% of titanate coupling agent at 60 °C for 20 min. The activation index increased from 2% for the raw alumina nanoparticles to 94.9% for the modified alumina nanoparticles, while the oil absorption value decreased from 75.2 mL/100 g to 55.8 mL/100 g. The sedimentation rate of the slurry decreased from 26% to 4% after modification of the nanoparticles, and the volume of nanoparticles increased appreciably from 35 vol% to 45 vol%. The surfaces of the green tapes prepared using slurries with modified alumina nanoparticles were smooth without visible defects. [ABSTRACT FROM AUTHOR]

The design of effective multi-view subspace clustering (MSC) algorithms has recently garnered significant research attention. Herein, to effectively improve the recognition performance and anti-noise interference ability of an MSC model, we propose a novel MSC algorithm, termed as robust multi-view subspace enhancement representation, based on collaborative constraints and a Hilbert–Schmidt independence criterion (HSIC) induction method. To mine the complementary information between different views, we apply the HSIC as a diversity regularization term. Specifically, to enhance the diagonal block structure of a subspace representation, a new sparse constraint is introduced on the product of itself and the transpose of the subspace representation matrix in a multi-view subspace learning model. Furthermore, hypergraph regularization and a low-rank idea are considered to capture the local geometric structure and clean data. In addition, to optimize our model, we adopt an augmented Lagrangian multiplier method and discuss the convergence of the model. Extensive experiments on six challenging datasets reveal that the proposed method achieves a highly competent objective performance with and without noisy views, as compared with several state-of-the-art multi-view clustering methods. [ABSTRACT FROM AUTHOR]

Proprotein convertase subtilisin/kexin type 9 (PCSK9) regulates plasma low-density lipoprotein cholesterol (LDL-C) levels by promoting the degradation of hepatic LDL receptors (LDLRs). Current therapeutic approaches use antibodies that disrupt PCSK9 binding to LDLR to reduce circulating LDL-C concentrations or siRNA that reduces PCSK9 synthesis and thereby levels in circulation. Recent reports describe small molecules that, like therapeutic antibodies, interfere with PCSK9 binding to LDLR. We report an alternative approach to decrease circulating PCSK9 levels by accelerating PCSK9 clearance and degradation using heterobifunctional molecules that simultaneously bind to PCSK9 and the asialoglycoprotein receptor (ASGPR). Various formats, including bispecific antibodies, antibody-small molecule conjugates, and heterobifunctional small molecules, demonstrate binding in vitro and accelerated PCSK9 clearance in vivo. These molecules showcase a new approach to PCSK9 inhibition, targeted plasma protein degradation (TPPD), and demonstrate the feasibility of heterobifunctional small molecule ligands to accelerate the clearance and degradation of pathogenic proteins in circulation. [Display omitted] • ASGPR-targeting heterobifunctional molecules lead to the clearance of PCSK9 in vivo • PCSK9 is cleared by bispecific antibodies, antibody conjugates, and small molecules • PCSK9 clearance requires binding to both the ASGPR and to PCSK9 • Heterobifunctional molecules do not lead to significant degradation of LDLR or ASGPR Bagdanoff et al. describe heterobifunctional molecules that mediate in vivo clearance of the pathologically relevant plasma protein PCSK9 in mice, demonstrating rapid, ASGPR-dependent clearance using multiple classes of heterobifunctional constructs including bispecific antibodies, antibody-drug conjugates, and small molecules. [ABSTRACT FROM AUTHOR]