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The Ru-catalyzed carbonylation of alkenes with CO2 as a C1 surrogate and imidazole chlorides as the promotor is investigated by a combination of computational and experimental study. The conversion rate of CO2 to CO is positively correlated with the efficiency of both hydroesterification and hydroformylation, which is found facilitated in the presence of chloride additives with a decreasing order of BmimCl ∼ B3MimCl > BmmimCl ∼ LiCl. Taking the hydroesterification with MeOH as a representative example, BmimCl bearing C–H functionality at the C2 site of the cation assists the reduction of CO2 to CO as a hydrogen donor medium, with the anion and cation acting in a synergistic fashion. Subsequent insertion of CO2 into the formed Ru–H bond with the assistance of chloride anion produces the Ru–COOH species, which ultimately accelerates the activation of CO2.

Syndrome-trellis codes (STCs) are commonly used in image steganographic schemes, which aim at minimizing the embedding distortion, but most distortion models cannot capture the mutual interaction of embedding modifications (MIEMs). In this article, a secure halftone image steganographic scheme based on a feature space and layer embedding is proposed. First, a feature space is constructed by a characterization method that is designed based on the statistics of 4 x 4 pixel blocks in halftone images. Upon the feature space, a generalized steganalyzer with good classification ability is proposed, which is used to measure the embedding distortion. As a result, a distortion model based on a hybrid feature space is constructed, which outperforms some state-of-the-art models. Then, as the distortion model is established on the statistics of local regions, a layer embedding strategy is proposed to reduce MIEM. It divides the host image into multiple layers according to their relative positions in 4 x 4 blocks, and the embedding procedure is executed layer by layer. In each layer, any two pixels are located at different 4 x 4 blocks in the original image, and the distortion model makes sure that the calculation of pixel distortions is independent. Between layers, the pixel distortions of the current layer are updated according to the previous embedding modifications, thus reducing the total embedding distortion. Comparisons with prior schemes demonstrate that the proposed steganographic scheme achieves high statistical security when resisting the state-of-the-art steganalysis.

The deviations of trajectory and attitude angle for internal store separation are evaluated by two wind tunnel test methods. One is the Freedrop Test (FDT), which is known as unsteady and time-dependent method of scaled model. The other is the Captive Trajectory System (CTS) test, which is usually regarded as a quasi-steady and time-averaged test technology. The result shows that there is a streamwise adverse pressure gradient on the cavity resulting in a nose-up pitching moment coefficient (>0) acting on the store model. When the initial pitch angular velocity is 0, the store exits the shear-layer with a nose-up pitch attitude causing the store to climb back towards and collide with the aircraft. However, the store passes through the shear-layer into the freestream with a nose-down pitch, which causes a successful separation event when the initial pitch angular velocity

PLLA- magnesium composites have been widely investigated as potential biodegradable materials for bone implants. Lower/higher corrosion resistance of the crystalized/amorphous magnesium alloys allows tailoring of biodegradability rate. In this work, the amorphous Mg65Zn30Ca5 was investigated versus traditional crystalized Mg65Zn30Ca5, and a PLLA-Mg65Zn30Ca5 composite has been successfully fabricated using hot injection process. Furthermore, the high corrosion resistance of the amorphous Mg65Zn30Ca5 prevented the high alkalization and deterioration of mechanical strength. In addition, the high Zn content intended to improve the glass forming ability, also enhances the anti-bacterial property of the PLLA-Mg65Zn30Ca5 composite. The remarkable performance of the PLLA-Mg65Zn30Ca5 composite shows its promising application in bone repair and tissue regeneration.

As one type of time series, interval-valued time series (ITS) is encountered frequently in many fields such as finance, environment, agriculture and so on since it can describe the uncertainty and variability of observed variables. The modeling of ITS is an ongoing issue pursued by researchers. In this paper, a novel rule-based granular ITS model is proposed by considering the interval-valued data as interval information granules in the framework of granular computing (GrC). The development of the proposed granular model consists of three components with progressive relationship, that is, the generation of granular prototypes, the formation of initial granular model and the refinement of the initial granular model. Further, the detail computation of reasoning of the corresponding granular model is also given. The resulting granular models have not only interpretability but also an ability to process ITS containing linguistic variables. Numerical experiments on six financial datasets and two meteorological datasets from real world reveal the impact of the parameter involved in the proposed method on the resulting granular model, and also exhibit that the resulting granular model is superior to seven existing competitive models including interval Holt one, multi-output support vector regression one and interval arithmetic-based multilayer perceptron one etc.

The morphology modulation of multi-level structures and the multifunctional design of their composites are challenging research priorities in the field of electromagnetic wave absorption. In this work, the abandoned polyurethane is adopted as a sacrificial template of a three-dimensional carbon network. The morphology-controlled Fe/Fe2O3@porous carbon composites with highly cross-linked 3D structures are synthesized by simple hydrothermal and thermal treatments. Among them, the PM-700 with a coral-like structure has a minimum reflection loss of −54.7 dB at a thickness of 1.4 mm and an effective absorption bandwidth of 6.4 GHz (10.8–18 GHz) at 1.9 mm. The excellent absorption performance is attributed to the three-dimensional magnetic conductive network, which provides superior impedance matching, synergistic effects of dual-loss mechanisms, and multiple attenuation. Furthermore, benefiting from its unique three-dimensional structure, the PM-700 possesses low density (0.088 g/cm3), excellent mechanical properties (withstand more than 4000 times of its own weight), and high thermal management (thermal insulation and flame retardancy). Meanwhile, PM-700 exhibits excellent infrared stealth performance, which is conducive to the development of multi-band compatible stealth materials. This work not only contributes to the conservation of resources and reuse of wasted polyurethane, but also facilitates the multifunctional application of microwave absorbing materials with multi-level structures.

BiSe has emerged as a promising Te-free high-performance thermoelectric (TE) material base owing to its ultra-low lattice thermal conductivity caused by the Bi bilayers in its lattice. Herein, the TE properties of BiSe were modified by Sn doping and ball milling to improve its performance. The ball milling process reduced the grain size of the samples and affected their anisotropy during the pressing process, leading to the random arrangement of the (00 l ) plane, which improved the electrical conductivity of the samples in the direction parallel to the spark plasma sintering direction and increased the Seebeck coefficient. The increased defects and smaller grain size of the samples due to Sn doping and ball milling enhanced the scattering of phonon transport, thereby decreasing the lattice thermal conductivity. The improvement in the ZT of the samples was realized through the improvement in their thermal and electrical transport. The Spark plasma-sintered bulk of the ball-milled Bi0.9Sn0.1Se sample exhibited a high-power factor of 8.4 μW · cm−1 · K−2 at 473 K and an ultra-low lattice thermal conductivity of 0.43 W · m−1 · K−1 at 673 K along with the maximum ZT value of 0.32 at 473 K, which is 31.6% higher than that of the pristine BiSe sample.

Computational study on relationship between molecular structure and property of small molecule hole-transporting materials (HTMs) is an efficient pathway to acquire potential HTMs for perovskite solar cells (PSCs). Herein, by conjugating the acceptor groups of electron-deficient diazatriphenylene (DAT), tetraazatriphenylene (TAT) and hexaazatriphenylene (HAT), and p-methoxy-substituted triphenylamine (MeOTPA) electron-donors, six novel donor–acceptor-donor (D-A-D) typed HTMs (SM11 ~ SM16) are designed. Furthermore, three thiophene-substituted acceptors (SM17 ~ SM19) are also investigated. The influences of acceptor moiety on the performance of HTMs are studied by carrying out theoretical chemical calculations. Compared with the reported HTM with triphenylene unit (TPH-T), the new tailored HTMs (SM11 ~ SM19) exhibit more negative highest occupied molecular orbital (HOMO) energy levels and slightly red-shifted light absorption due to the increased electron-deficient property of acceptor group and linked positions with the MeOTPA-donor. Meanwhile, our results show that the small torsion angle between the acceptor and the donor is beneficial to promote the hole transport in HTMs, and the thiophene units on acceptor may also be helpful to enhance the charge mobility of HTMs. In addition, the large charge transfer amounts and small exciton binding energies are found for designed HTMs, which will be favorable to facilitate the electron-hole separation in HTMs. The stability of HTMs may be decreased based on the calculated results of electrostatic surface potential and absolute hardness. We hope this work could highlight the potential of azatriphenylene acceptor-based D-A-D typed HTMs for efficient PSCs.

As a dielectric loss-type absorber, lamellar transitional metal chalcogenides (LTMCs) become more and more popular in the electromagnetic (EM) absorbing field due to their unique two-dimensional sheet structure. However, it remains challenging for metallic sulfides to obtain magnetic loss, further promoting loss mechanism. Herein, magnetic Fe3S4 LTMCs micro-flowers@ wax gourd aerogel-derived carbon composites are fabricated through a facile pyrolysis process and subsequent hydrothermal method. Compared to a pure biomass carbon or Fe3S4, Fe3S4@C composites exhibited an optimized and adjustable EM characteristic, which can be put down to the synergistic effects between the dielectric/magnetic loss and the impedance match. The sample shows superior EM absorption properties with a minimum reflection loss (RL) of −58.85 dB at 3.1 mm and a broad effective bandwidth (EBW) of 5.40 GHz at the matching thickness of 2.0 mm with a filling ratio of 20 wt%. In addition, the radar cross section (RCS) simulation confirms that the material can effectively suppress EMW (−8.51 dB m2 at zero degree) in practical applications. Therefore, it is believed that the as-prepared Fe3S4@C hybrids can be one of the prospective candidates as high-efficiency EMW absorbers.

Social networks are everywhere and currently transmitting very large messages. As a result, transmitting secret messages in such an environment is worth researching. However, the images used in transmitting messages are usually compressed with a JPEG compression channel, which is lossy and damages the transmitted data. Therefore, to prevent secret messages from being damaged, a robust JPEG steganography is urgently needed. In this paper, a secure robust JPEG steganographic scheme based on an autoencoder with an adaptive BCH encoding (Bose-Chaudhuri-Hocquenghem encoding) is proposed. In particular, the autoencoder is first pretrained to fit the transformation relationship between the JPEG image before and after compression by the compression channel. In addition, the BCH encoding is adaptively utilized according to the content of cover image to decrease the error rate of secret message extraction. The DCT (Discrete Cosine Transformation) coefficient adjustment based on practical JPEG channel characteristics further improves the robustness and statistical security. Comparisons with prior state-of-the-art schemes demonstrate that the proposed robust JPEG steganographic algorithm can provide a more robust performance and statistical security.

In order to obtain a high accuracy with high machining efficiency for finishing hard alloy metal material, we proposed a hybrid finishing method which is electrochemical (ECM) effects assisted magnetic abrasive finishing (MAF). In this study, the electrochemical magnetic abrasive finishing (EMAF process) was divided into EMAF stage and MAF stage. The metal surface can be easily finished with the passive films formed in electrochemical reactions. Simultaneously, the passive films can be removed by frictional action between magnetic brush and workpiece surface. Thus, the essence of EMAF process is to form and remove the passive films on the workpiece surface. This study focused on investigating the finishing mechanism and finishing characteristics of EMAF process. Compared with traditional MAF process, it can be confirmed that the finishing efficiency is remarkably improved more than 75% by EMAF process, and the surface roughness is also lower in EMAF process. The optimal experimental result of EMAF process showed that the surface roughness was reduced to less than 30 nm from the original surface roughness 178 nm after 4 min in EMAF stage, and the surface roughness was finally reduced to 20 nm after 10 min in MAF stage. The material removal rate in hybrid finishing stage was nearly 7 times than that in MAF stage. Additionally, the effective finishing area in EMAF process was about 70% of that in MAF process.

Recently, it is in urgent need of exploring high-performance microwave absorbers to address the electromagnetic pollution. To this end, low dimensional materials have received the great attention due to their unique microstructures and properties. Constructing heterostructure materials by stacking 0D, 1D and 2D materials can combine the merits of the individual blocks while weakening their shortcomings. Herein, a novel 1D heterostructure hybrid was successfully synthesized through anchoring the flower-like 2D MoS2@Fe3O4 0D nanospheres on the surface of the 1D hollow carbon microtubes (CT) derived from cattail by electrostatic self-assembly. Notably, the minimum reflection loss (RLmin) and an effective absorption bandwidth (EAB) of the composite can reach −62 dB at 2.09 mm and 6.8 GHz at 2.35 mm, respectively, with a filling ratio of only 8%. It reveals that the rational combination of magnetic and dielectric materials with different dimensions can effectively tune the impedance matching and attenuation constant, leading to the superior microwave absorption performance. Furthermore, the unique microstructure of MoS2@Fe3O4/CT endows it with good hydrophobicity, highly desired for self-cleaning purposes. This work highlights that the 1D heterostructure MoS2@ Fe3O4@CT composites can serve as a promising candidate for the high-performance microwave absorber with lightweight, wideband, strong reflection loss and hydrophobicity.

Exceptional points (EPs) are the singularities of a non-Hermitian system where the eigenenergies and eigenstates simultaneously coalesce, a topological property that gives rise to a plethora of exotic phenomena. Probing the EPs and associated effects requires the system to go through the EPs. However, the ultrahigh sensitivity of an isolated EP to the external disturbances makes accessing the EPs difficult. To overcome this limit, many approaches have been presented to form the exceptional line/ring and surface. Here, we demonstrate that a quantum exceptional chamber, which is a three-dimensional collection of the EPs, can be constructed in the coupled plasmon-quantum dot (QD) systems by the nondipole effect of the QD. For an asymmetric QD adjacent to a plasmonic nanoparticle, it is found that the contributions of multipole transitions to the coupling strength can be larger than that of dipole transition. The orientation-dependent quantum interference between the dipole and multipole transitions can lead to controllable switch between the weak and strong coupling, and provides an extra degree of freedom to form a high-dimension EP space. Our approach provides a robust platform for accessing the quantum EPs and related applications.

The active color-changing ability of many living species has inspired scientists to replicate the optical property into soft wet and tissue-like hydrogel materials. However, the color-changing processes of most reported examples are controlled by the traditional stimuli (e.g., pH, temperature, and ions), which may suffer from the residual chemical product accumulation, and have difficulty in achieving local control and integration into the commercial robots, especially when applied as biomimetic skins. Herein, inspired by the nervous (bioelectricity) control of skin color change in cephalopods, we present an electrically powered multicolor fluorescent hydrogel system with asymmetric configuration that couples thermoresponsive fluorescent hydrogel with stacked graphene assembly (SGA)-based conductive paper through luminous paint as the middle layer. Owing to the highly controllable electrical stimulus in terms of amplitude and duration, the Joule heat supplied by SGA film can be regulated locally and in real time, leading to precise and local emission color control at low voltage. It also avoids the addition of any chemicals. Furthermore, the electrically powered color-changing hydrogel system can be conveniently integrated into the commercial robots as biomimetic skins that help them achieve desirable camouflage, display, or alarming functions.

This study explores a novel WNbMoTaV high-entropy thin film (HETF) in amorphous structure via pulsed laser deposition system. The formation of amorphous structure of this high-entropy alloy is ascribed to the high cooling rate during the deposition process. The HETF shows a smooth surface with a height fluctuation of less than 13 nm. This film has a high electrical resistivity of ~ 320.6 μΩ∙cm and a low corrosion current density of 0.088 μA/cm2. The corrosion resistance of the HETF at ambient temperature is superior to the conventional AISI 316L stainless steel. The high electrical resistivity and excellent corrosion resistance of the HETF are mainly attributed to its chemical disorder, cocktail effect and homogeneous amorphous structure. This experimental phenomenon not only provides a basis for the preparation of amorphous alloy films with low glass forming ability by pulsed laser deposition system, also promotes the potential application of WNbMoTaV HETF in the microelectronic components as resistivity sensors.

We show a top-down synthesis approach to mass-produce phosphorene-graphene nanosheet composites with superior cycle stability and rate capability. Currently, using exfoliation to achieve two-dimensional (2D) materials is primarily limited to pure crystals. We discover that high-quality nanoscale 2D composite phosphorene-graphene sheets can be directly exfoliated from extremely low-cost bulk three-dimensional (3D) black phosphorus-graphite composites synthesized by mechanical milling while maintaining the chemical bonding and intimate electronic contact between 2D composite layers. The hybrid phosphorene-graphene material delivers high reversible capacities of 2030, 2003, and 1597 mAh/g at high current densities of 2, 4, and 6 A/g, respectively. Quantifying the dimensional electrochemical performance, we show that 2D phosphorene-graphene nanosheets not only have excellent electrochemical kinetics for fast lithium-ion diffusion and storage but also maintain the overall structural robustness of the entire electrode for long-term cyclability. This scalable synthesis paves the way for the practical application of phosphorene-graphene materials in batteries.

Poly(6-cyanoindole) (P(CnId)) is blended with poly(styrenesulfonic acid) via doping periods of 1, 10, 20, and 30 s to obtain P(CnId)–1PSS, P(CnId)–10PSS, P(CnId)–20PSS, and P(CnId)–30PSS electrodes, respectively. FT-IR studies have revealed that P(CnId) is doped with PSS. Pt particles can be doped into P(CnId)–1PSS, P(CnId)–10PSS, P(CnId)–20PSS, and P(CnId)–30PSS by chronocoulometry (0.15 C) using electrodeposition to acquire P(CnId)–1PSS–Pt, P(CnId)–10PSS–Pt, P(CnId)–20PSS–Pt, and P(CnId)–30PSS–Pt films, respectively. For comparative purposes, in this study, Pt particles were deposited into P(CnId) under the same conditions. Scanning electron microscopy (SEM) characterization revealed that platinum distributes more uniformly into the as-prepared P(CnId)–10PSS films. The anodic peak currents could be clearly observed to reach the saturation point at a methanol concentration larger than 0.8 M. A large electrocatalytic current towards methanol oxidation (27 mA cm−2 mg−1) was noticed in P(CnId)–10PSS–Pt electrodes in comparison to P(CnId)–Pt without PSS (6.3 mA cm−2 mg−1) at +0.86 V (vs. RHE), indicating that the P(CnId)–10PSS–Pt electrode reveals potential applicability as an electrocatalyst support.

We present an O-band four-level pulse amplitude modulation (PAM4) transmitter based on a dual-drive silicon modulator with binary driving electronics at CMOS voltages, effectively eliminating the need for power-hungry digital-to-analog converters (DACs) and RF drivers. The fabricated dual-drive silicon modulator has cascaded p - n junction and p - i - n junction embedded in each arm of Mach-Zehnder interferometer, implementing high-speed data modulation and efficient bias control, respectively. Power dissipation of around 611 fJ/bit is obtained when synthesizing 46 Gb/s PAM4, showing high power efficiency. The fabricated silicon modulator exhibits a π-voltage-length product of 4.5 V·mm, and a 3-dB bandwidth of up to 27 GHz. Meanwhile, to implement a power-efficient PAM4 transceiver, the digital signal processing (DSP) at the receiver side is also discussed by balancing the performance and complexity. With a low-complexity DSP, negligible power penalty is observed after transmission over 38-km SSMF for both synthesized 20 Gb/s and 40 Gb/s PAM4. The presented PAM4 transmitter takes the advantages of both carrier-depletion and carrier-injection phase shifters for effective data modulation and bias control in PAM4 signalingand provides a power-efficient transmitter solution by eliminating the use of power-hungry DACs or RF drivers for datacenter interconnects.

To achieve excellent treatment performance of complex and time-varying characteristics, the operation of wastewater treatment process (WWTP) has been considered as a dynamic multiobjective control problem. In this paper, an optimal controller, based on a dynamic multiobjective particle swarm optimization (DMOPSO) algorithm, is developed to deal with the dynamic multiple conflicting criteria [i.e., effluent quality (EQ), operation cost, and operation stability]. The novelties and advantages of this proposed DMOPSO-based optimal controller (DMOPSO-OC) include the following two aspects. First, an integrated optimization framework, where the multiple objectives not only conflict with each other but also change over time, is able to catch more characteristics of WWTP than the existing works. Second, a DMOPSO algorithm, with an adaptive global best selection mechanism, is designed to solve the multiobjective optimization problem (MOP) for the proposed optimal controller, thus leading to a significant improvement of optimal synthesis for performance. Finally, the proposed DMOPSO-OC is tested in the benchmark simulation model No. 1 (BSM1) and implemented in a real WWTP to evaluate its effectiveness. The experimental results demonstrate that this proposed DMOPSO-OC can achieve a significant improvement in optimal control performance and obey the requirement of multiple conflicting criteria.

Due to the diversity of mineral particle features in rock, including sizes, shapes, arrangements, and structural connections, the color image of the rock sample surface at laboratory scale is quite complex. Thus, unacceptable misjudgement and information loss often occur when the traditional image processing algorithms are adopted. To improve the accuracy of fracture extraction, a method based on image processing algorithms is proposed in this paper to extract fractures from 3D point clouds. First, a high-precision original depth image is generated by gridding the rock surface point cloud data with the Kriging interpolation. The hill shading method is then applied to further clarify the fractures. Finally, the fractures are extracted from depth images and compared with color images. The results show that the integrity of the fracture skeleton is significantly improved and the error rate is reduced. In combination with color images, the physical fractures and other fracture-like features can be distinguished. The proposed method provides a new idea for extracting fractures in various destructive experiments on rocks, and may be developed for recognition of discontinuities at typical engineering scale.

The atomic diffusion in transition metal dichalcogenides (TMDs) van der Waals heterojunctions (HJs) strongly modifies their optoelectronic properties in the nanoscale. However, probing such localized properties challenges the spatial resolution and the sensitivity of a variety of analytic tools. Herein, a multimodal nanoscopy (based on tip enhanced Raman spectroscopy (TERS) and photoluminescence (TEPL)) combined with the Kelvin probe force microscopy (KPFM) method was used to probe such nanoscale localized optoelectronic properties induced by atomic diffusion. Chemical vapor deposition (CVD)-grown lateral bilayer (2L) WS2/MoS2 HJs were imaged with a spatial resolution better than 40 nm via TERS and TEPL mapping by using intrinsic Raman and photoluminescence (PL) peaks. The contact potential difference (CPD), capacitance, and PL variation in a nanoscale vicinity of the HJ interface can be correlated to the local stoichiometry variation determined by TERS. The diffusion coefficients of W and Mo were obtained to be ∼0.5 × 10-12 and ∼1 × 10-12 cm2/s, respectively, by using Fick's second law. The obtained results would be useful to further understand the localized optoelectronic response of the TMDs HJs.

With the continuous advancement of science and technology, the improvement of mobile terminal hardware performance and the large-scale popularization of smart phones have brought new experiences and methods to surveying and mapping work. This article mainly studies the application of remote sensing image processing technology based on mobile augmented reality technology in surveying and mapping engineering. First, perform grayscale processing on the image in the experiment, then remove the noise in the image and smooth the image through the median filter method and finally use the Canny operator to perform edge detection to obtain a binarized image containing only the target object, and this is done by image feature extraction. After using three-dimensional scanning modeling to extract the image feature points, the target manager is used for sample analysis. Obtain the projection matrix through the interface, and then perform coordinate conversion to complete the positioning of the target scene. In this paper, the BRISK feature point detection algorithm with fast speed and small calculation is used to detect the target, and SVM is used for remote sensing feature classification. Experimental data show that the recognition success rate of the algorithm is 84%. The results show that mobile augmented reality technology and remote sensing image processing technology can improve the efficiency and accuracy of surveying and mapping engineering, and have strong ease of use and stability.

This paper describes how piezoelectric accelerometers can be applied to motion control systems for performance enhancements. Piezoelectric accelerometers are known for their wide frequency ranges to sense dynamic acceleration. However, they are unable to measure static and quasi-static acceleration. Since positional sensors generally exist in motion control systems, this paper presents two acceleration observers that fuse piezoelectric accelerometers and positional sensors and are able to achieve high-quality observation of acceleration, including static and quasi-static components. The proposed observers are applied to a robotic manipulator, and experimental results confirm feasibility and effectiveness of the proposed acceleration observers.

Ferroelectric barium titanate nanoparticles (BTO NPs) may play critical roles in miniaturized passive electronic devices such as multi-layered ceramic capacitors. While increasing experimental and theoretical understandings on the structure of BTO and doped BTO have been developed over the past decade, the majority of the investigation was carried out in thin-film materials; therefore, the doping effect on nanoparticles remains unclear. Especially, doping-induced local composition and structure fluctuation across single nanoparticles have yet to be unveiled. In this work, we use electron microscopy-based techniques including high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), integrated differential phase contrast (iDPC)-STEM, and energy dispersive X-ray spectroscopy (EDX) mapping to reveal atomically resolved chemical and crystal structure of BTO and strontium doped BTO nanoparticles. Powder X-ray diffraction (PXRD) results indicate that the increasing strontium doping causes a structural transition from tetragonal to cubic phase, but the microscopic data validate substantial compositional and microstructural inhomogeneities in strontium doped BTO nanoparticles. Our work provides new insights into the structure of doped BTO NPs and will facilitate the materials design for next-generation high-density nano-dielectric devices.

The integration of molecular design and imidazole ionic liquids produces a synergistic effect to enhance and fine-tune the molecular sieve capability of polyimide (PI) membranes. The most difficult problem was to choose the right ionic liquids and moderate polymer combination. In this work, a series of systems of CO₂ in [EMIM][Tf₂N], [EMIM][BF₄], and [EMIM][PF₆] composited with 6FDA-based PI with different IL concentrations were discussed by all-atom molecular dynamics simulations. The results indicated that the CO₂ diffusion coefficient decreases with the compatibility of the PI structure with CO₂ molecules and increases with an increased IL concentration of up to 75 wt %. Therefore, this study may provide guidance for the design of PI membranes.

Blood glucose (BG) prediction is an effective approach to avoid hyper- and hypoglycemia, and achieve intelligent glucose management for patients with type 1 or serious type 2 diabetes. Recent studies have tended to adopt deep learning networks to obtain improved prediction models and more accurate prediction results, which have often required significant quantities of historical continuous glucose-monitoring (CGM) data. However, for new patients with limited historical dataset, it becomes difficult to establish an acceptable deep learning network for glucose prediction. Consequently, the goal of this study was to design a novel prediction framework with instance-based and network-based deep transfer learning for cross-subject glucose prediction based on segmented CGM time series. Taking the effects of biodiversity into consideration, dynamic time warping (DTW) was applied to determine the proper source domain dataset that shared the greatest degree of similarity for new subjects. After that, a network-based deep transfer learning method was designed with cross-domain dataset to obtain a personalized model combined with improved generalization capability. In a case study, the clinical dataset demonstrated that, with additional segmented dataset from other subjects, the proposed deep transfer learning framework achieved more accurate glucose predictions for new subjects with type 2 diabetes.

Numerous learning methods for fuzzy cognitive maps (FCMs), such as the Hebbian-based and the population-based learning methods, have been developed for modeling and simulating dynamic systems. However, these methods are faced with several obvious limitations. Most of these models are extremely time consuming when learning the large-scale FCMs with hundreds of nodes. Furthermore, the FCMs learned by those algorithms lack robustness when the experimental data contain noise. In addition, reasonable distribution of the weights is rarely considered in these algorithms, which could result in the reduction of the performance of the resulting FCM. In this article, a straightforward, rapid, and robust learning method is proposed to learn FCMs from noisy data, especially, to learn large-scale FCMs. The crux of the proposed algorithm is to equivalently transform the learning problem of FCMs to a classic-constrained convex optimization problem in which the least-squares term ensures the robustness of the well-learned FCM and the maximum entropy term regularizes the distribution of the weights of the well-learned FCM. A series of experiments covering two frequently used activation functions (the sigmoid and hyperbolic tangent functions) are performed on both synthetic datasets with noise and real-world datasets. The experimental results show that the proposed method is rapid and robust against data containing noise and that the well-learned weights have better distribution. In addition, the FCMs learned by the proposed method also exhibit superior performance in comparison with the existing methods. Index Terms-Fuzzy cognitive maps (FCMs), maximum entropy, noisy data, rapid and robust learning., The manuscript has been published on IEEE Transactions on Cybernetics

In this work, the 3D worm-like expanded graphite (EG)/2D MoS2 nanosheets hybrids were synthesized by a facile in-situ self-assembled hydrothermal process. The 2D MoS2 nanosheets were uniformly and vertically grown on the surface of the 3D worm-like graphite, and interconnected with each other to form a hierarchical network structure. The unique honeycomb-like porous microstructure of the worm-like EG was conducive to the multiple scatterings and reflections, interconnected conductive network and improved impedance matching. In addition, the abundant heterogeneous interfaces in the MoS2/EG hybrids lead to enhanced dipole polarization and interfacial polarization. As a result, the MoS2/EG hybrids exhibited high-efficiency electromagnetic wave (EMW) absorption performance with an ultra-low filling ratio of 7 wt %. The MoS2/EG composites displayed an optimal reflection loss (RL) value of −52.3 dB at 15.1 GHz and a wide effective absorption bandwidth (EAB) of 4.1 GHz with a thickness of only 1.6 mm. The present work provides a significant guidance for the design and fabrication of the ultra-lightweight EMW absorbers with high performances.

In this study, we demonstrate the axiotaxy driven growth of belt-shaped InAs nanowires using Au catalysts by molecular beam epitaxy. It is found that, the zinc-blende structured InAs nanowires, with the features of [ $$\bar{1}\bar{1}\bar{3}$$ ] growth direction and extensive { $$1\bar{1}0$$ } side-surfaces, are induced by catalysts in Au-In α phase through the axiotaxy growth, in which the lattice mismatch between the projections of atomic planes onto nanowire/catalyst interfaces is minimized by forming extraordinary tilted interfaces. Our atomic-resolution in situ TEM heating experiments show that the catalysts remained in the solid state of Au-In α phase during the axiotaxy growth, by which the vapor—solid—solid growth mechanism can be confirmed. Through manipulating the growth direction, this unusual growth mechanism can provide a practical pathway to control the morphology of the low-dimensional nanomaterials, from conventional nanowires to belt-shaped nanowires utilizing a significant lateral growth, simply using nanoparticles as catalyst.

There is an emerging need for high-sensitivity solar-blind deep ultraviolet (DUV) photodetectors with an ultra-fast response speed. Although nanoscale devices based on Ga2O3 nanostructures have been developed, their practical applications are greatly limited by their slow response speed as well as low specific detectivity. Here, the successful fabrication of two-/three-dimensional (2D/3D) graphene (Gr)/PtSe2/β-Ga2O3 Schottky junction devices for high-sensitivity solar-blind DUV photodetectors is demonstrated. Benefitting from the high-quality 2D/3D Schottky junction, the vertically stacked structure, and the superior-quality transparent graphene electrode for effective carrier collection, the photodetector is highly sensitive to DUV light illumination and achieves a high responsivity of 76.2 mA/W, a large on/off current ratio of ~ 105, along with an ultra-high ultraviolet (UV)/visible rejection ratio of 1.8 × 104. More importantly, it has an ultra-fast response time of 12 µs and a remarkable specific detectivity of ~ 1013 Jones. Finally, an excellent DUV imaging capability has been identified based on the Gr/PtSe2/β-Ga2O3 Schottky junction photodetector, demonstrating its great potential application in DUV imaging systems.

Motivated by the intelligent reflectingsurface (IRS) applications in multi-input multi-output (MIMO) communication systems which can improve capacity and energy performance, we apply the IRS in the distributed MIMO (DMIMO) radar systems to improve the target detection performance. In the IRS-aided DMIMO radar systems, each IRS is controlled by its receiver, and the receivers can receive the signals reflected from the target and the IRS simultaneously. In the proposed method, the IRS is first optimized, and then the target detection is carried out. The detection probability, false alarm probability, and the detector's divergence are analyzed and compared with the traditional DMIMO radar. Simulations verify the superiorities of the proposed IRS-aided DMIMO radar.

Lithium-tellurium (Li-Te) batteries have attracted increasing attention as a next-generation energy storage system due to the appealing electrical conductivity and volumetric capacity. Porous carbon hosts are widely used for Te confinement to achieve good electrochemical performance in Li–Te batteries. However, there is a lack of understanding of the effect of carbon pore structure on the performance of Te/C cathodes. Herein, two types of carbons, one with micropores (ASAC25) and the other with mixed micropores and mesopores (ASAC30) are selected as Te hosts to clarify the role of carbon pore structure. Detailed investigations reveal that micropores, rather than mesopores, are critical for effective Te confinement due to complete infiltration of Te in micropores and enhanced Te and C interaction, thus enabling superior stability in ASAC25-Te. The dramatic capacity decline of ASAC30-Te is caused by the dissolution of bulky Te and the loss of active materials in long cycles. ASAC25-Te also achieved exceptional capacity retention of 83.3% after 500 cycles at 1C. Moreover, this work found that the ASAC25 carbon host should be partially filled with Te up to ∼60 wt% to accommodate volume change of Te. The clarification is expected to provide guidance on the further development of high-energy-density Te-based rechargeable batteries.

Background Food can be considered as a natural pool of biopolymer-based colloidal particles diverse in size, morphology, and functionalities. There remains considerable controversy on whether these particles can be absorbed from the intestinal lumen in their intact form even though numerous studies have confirmed the possibility of the absorption of intact nanoparticles across the intestinal wall. Scope and approach In this review, we comprehensively summarize the absorption process of nanoparticles, including mucus-penetrating, cellular uptake, and intracellular transportation. We then perform a detailed study on the absorption of food colloidal particles composed of protein, lipid and carbohydrate. The in-vivo transportation and biodistribution of nanoparticles is then summarized. We also specially discuss the dynamic colloidal aspects of food components which is of great importance to the food digestion and absorption. Finally, we analyze the safety issue of food nanoparticles since an increasing concern on this arises in the past decades. Key findings and conclusions External nanoparticles can be absorbed into cells through endocytosis, which can occur via different mechanisms. Like various fabricated nanoparticles, food colloidal particles potentially can also be absorbed in their intact form. However, previous studies rarely touch upon the absorption, biological fate, potential health effects, and safety of these colloidal particles. Their dynamic formation and disassembly process is also ignored. All these issues are of great importance to the food digestion and absorption mechanism and worth to be thoroughly studied. We attempt to coin all these relevant studies as “Colloidal Nutrition Science”, which aim to understand the food-body interaction from colloidal aspects.

Suitable metal–support interaction is of great significance for the supported Fischer–Tropsch catalyst. Herein, we synthesized a series of porous spinel MAl2O4 (M = Co, Mg, Zn) together with Al2O3,...

In the process of underground excavation with weak and broken surrounding rock, high-strength arch support is the primary bearing structure to resist rock pressure, especially after shotcrete layer cracks. Field destruction in underground excavation indicates that, with high ground pressure, the primary failure mode of arch is instability failure, which might lead to sudden loss of strength. Therefore, a quantitative analysis of arch instability in tunnel support design is necessary to avoid insufficient support strength so as to ensure the safety of underground engineering. The research method in this paper is based on the application of convergence-confinement method in underground arch support. The modified assumption of support characteristic curve (SCC) is proposed considering the instability failure of arch. The SCC of I-shaped arch and concrete-filled steel tubular (CFST) arch is constructed, respectively, based on mechanical analysis and verified by numerical simulation. A parametric analysis is also carried out to provide reference for arch design. Ground reaction curves (GRCs) of tunnel surrounding rocks with different lithology and ground stress considering arch failure mode are obtained to study the rock–arch interaction mechanism. The research results provide a theoretical reference for the design and application of arch support in related projects.

In this study, we achieved a facile and low-cost (18-22 USD/g) synthesis of spiro[fluorene-9,9-phenanthren-10-one]-based interfacial layer materials (MSs; designated MS-PC, MS-PA, MS-OC, and MS-OA). Carbazoles and dimethylacridine substituents with an extended π-conjugation achieved through ortho- or para-orientations were used as donors at the spiro[fluorene-9,9'-phenanthren-10'-one] moiety. Highly efficient and stable inverted perovskite solar cells (PSCs) with the device architecture of ITO/NiOx/MSs/perovskite/PC61BM/BCP/Ag can be achieved to improve the surface morphology of NiOx when MSs are adopted as the interfacial layer. During a morphological study, the ortho-orientated donor of MS-OC and MS-OA has spherical structures indicated that the films were smooth and that the films of perovskite deposited on them had large grain size and uniformity. The photoluminescence properties of the perovskite layers on the NiOx/MSs were showed better hole-transporting capabilities than the bare NiOx. The dual-functional interfacial layer has shown defect passivation effect, it not only improved the surface morphology of NiOx but also enlarged the perovskite layer grain size. The best PSC device performance of the NiOx/MS-OC was characterized by 22.34 mA cm-2 short-circuit current density (Jsc), 1.128 V open-circuit voltage (Voc), and 80.8% fill factor (FF), resulting in 20.34% power conversion efficiency (PCE). The NiOx/MS-OC PSCs showed good long-term device stability, even retained the original PCE of 93.16% after 370 days under argon (25 °C). Owing to the superior perovskite morphologies of the NiOx/MSs, the resulting devices outperformed the bare NiOx-based PSCs.

In view of the continuous increase in the amount of AIS data at sea and the existence of more abnormal points, it is difficult to construct ship trajectories based on AIS data. Aiming at this problem, a new method for identifying and repairing abnormal points in trajectories only based the AIS data of the ship itself is proposed. Longitude and latitude, speed, acceleration, direction and other parameters are comprehensively used to identify and repair the abnormal points in the method proposed. Compared with the methods based on single location data, it can effectively reduce the missed judgement of outliers. Compared with the methods based on trajectories clustering to judge singular point, this method does not require the data of historical trajectories to expand the application scope. The cubic spline method is used to interpolate points for the discontinuous segments to further improve the continuity and integrity of the ship trajectory. The results of AIS data processing and analysis on ships in actual sea areas verify the feasibility and effectiveness of the proposed method.

This article prepared a simvastatin-NLCs for the treatment of arteriosclerotic occlusive disease of lower limbs. Taking the size distribution, polydispersity coefficient, encapsulation efficiency and drug loading of simvastatin-NLCs as evaluation indicators, various prescription factors of simvastatin-NLCs were investigated. The in vitro release behavior and stability of simvastatin-NLCs were also investigated. A hyperlipidemia rat model was established using high-fat diets. SD rats fed ordinary diet were set as normal control groups. 20 rats, 20 in the simvastatin group and 20 in the simvastatin nanocarrier group. After 5 weeks of drug intervention, the rats were sacrificed and the aorta was taken to determine the smooth muscle cell apoptosis rate. Studies have shown that simvastatin nanocarriers can more effectively reduce blood lipids in hyperlipidemia rats, increase the rate of smooth muscle cell apoptosis in hyperlipidemia rats, and delay the onset of atherosclerosis.

Motivated by the improved capacity and energy performance by intelligent reflecting surface (IRS) in multiinput–multioutput (MIMO) communication systems, we apply the IRS in the colocated MIMO radar systems to increase the received power and improve the target detection performance. To deal with this, we introduce an IRS-assisted target detection algorithm, in which the reflection optimization with practical IRS model is carried out, and then the optimal beamforming for target detection is proposed. Meanwhile, the Cramer–Rao bound (CRB) of the proposed method shows the effectiveness of utilizing the IRS in MIMO radar systems. Simulation results illustrate that the proposed method can achieve better target detection performance. With the increased number of elements in the IRS, the proposed method has better angle resolution and detection probability compared with a non-IRS-assisted MIMO radar system.

Although low-dimensional materials have already been studied as attractive electromagnetic wave absorption materials due to unique structure, it is still hard to acquire both ultrathin matching thickness and strong absorbing capability. Herein, multilayer-sandwiched Ti3C2Tx MXene heterostructure decorated with one-dimensional Co nanochains has been synthesized successfully through a facile in situ process. As expected, the EM wave absorbers with ultrathin matching thickness and excellent absorbing capability are realized in the MXene composites. Compared with the MXene/Co nanoparticles, the MXene/Co nanochains composites achieved a minimum reflection loss of −46.48 dB with an ultrathin matching thickness of only 1.02 mm at 16.75 GHz. The intrinsic mechanism of the absorption revealed that the conductive loss, polarization loss, magnetic loss and interlacing magnetic flux field effect contributed to the high-performance microwave absorption. This work not only provided a unique direction for the designing and synthesizing of highly efficient EM wave absorbents with an ultrathin thickness, but also shed additional light on the understanding of the absorbing mechanism.

The morphology effect of tungsten oxide on the NH3-SCR activity of the supported CeO2 catalyst was experimentally investigated by comparing the catalytic performance of WO3 in different morphologies. Nanoparticles (W-NP), nanorods (W-NR) and microspheres self-assembled by nanorods (W-MP) of WO3 were synthesized by using different carboxylic acid structure-directing agents. Based on this, the impregnation method was adopted to form the composite catalysts including the Ce/W-NP, the Ce/W-NR and the Ce/W-MP. After the impregnation of Ce species, a new redox cycle of Ce4++W5+↔Ce3++W6+ is formed due to the interaction of W and Ce ions, which significantly facilitates the redox reaction on the composite catalyst. However, compared with nanorods (W-NR) and microspheres self-assembled by nanorods (W-MP), WO3 nanoparticles (W-NP) enclosed with (0 0 1) facets of the hexagonal WO3 shows the best redox ability due to the largest molar ratio of W5+/(W5++W6+) and the highest concentration of Ce4+ on the surface of Ce/W-NP, which was proven by the results of XPS. As a consequence, the Ce/W-NP presents the strongest surface redox properties and the largest molar ratio of Oα/(Oα+Oβ), which is beneficial to promote the NH3-SCR activity of the catalyst. It is worth mentioning that the morphology of tungsten oxide that remarkably affects the activity of the catalyst is determined by tartaric acid, citric acid and oxalic acid, indicating the significance of the structure-directing agents for improving the NH3-SCR activity of the impregnated Ce/W catalyst.

In this study, ultrasound measurement was used to reveal objective differences between male and female patients in arm burn scar thickness. An experienced physician trained by radiologists used an ultrasound machine and a digital height and weight scale to measure normal skin and scar thicknesses and patients’ body mass indices (BMIs). On the day of testing, the pressure garments (PGs) on the patients’ arms were removed. Bonferroni 95% confidence intervals for scar thicknesses measured in female and male patients were 0.135 to 0.212 cm and 0.045 to 0.113 cm, respectively; the individual confidence level was 97.5%. For both groups, a P value of

Electromagnetic pollution often interferes with the normal use of sophisticated electric devices leading to the necessity of developing electromagnetic wave absorbers with light weight and strong absorption ability. Herein, we synthesized two-dimensional magnetized MXene hybrids by electrostatic assembly of negatively charged few-layered Ti3C2Tx (MXene) with positively charged hollow Fe3O4 nanoparticles (HFO). The few-layered MXene was obtained by etching Ti3AlC2via a modified LiF–HCl method followed by a sonication process, while HFO was fabricated by a facile hydrothermal process. The MXene/HFO hybrids were light weight and achieved a high EM wave absorption performance (RLmin of −63.7 dB at a thin thickness of 1.56 mm). Moreover, the strong EM wave attenuation resulted from the synergistic effect arising from dielectric loss, magnetic loss, interface polarization and improved impedance matching. Therefore, the as-prepared magnetized MXene hybrids are expected to be candidates for high performance electromagnetic microwave absorbers.

Ionic liquids (ILs) play an important role in conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) based electronics and thermoelectrics through regulating morphology and electronic properties. Herein, the hole transport and interface electronic coupling properties of three kinds of IL ([BMIM]:[BF4], [BuPhIM]:[BF4], and [BnPhIM]:[BF4]) mediated PEDOT systems have been researched via multiscale molecular mechanics simulations and quantum mechanics calculations, where the cations of the ILs feature gradually extended π-conjugation. It is indicated that [BnPhIM]:[BF4] induces PEDOT to show more ordered π–π stacking than its counterparts, where the chains are oriented with face-to-face alignment. This is attributed to the larger evenness of the net charge distribution at the [BnPhIM]:[BF4]-PEDOT interface. Consequently, the average mobility in [BnPhIM]:[BF4]-PEDOT is 4.01 cm2 V−1 s−1 and the instantaneous maximum reaches 17 cm2 V−1 s−1, far surpassing its counterparts. Although the predicted PEDOT single crystal presents a well-ordered lamellar structure, the one-dimensional orientation causes hole tunneling along the nanowire-like direction, leading to its mobility lagging behind the [BnPhIM]:[BF4] decorated system by one order of magnitude. On the other hand, the interface electronic coupling and doping efficiency in [BnPhIM]:[BF4]-PEDOT is strengthened, confirming that improving the π-conjugation of the cation of the IL can enhance the mobility of PEDOT and interface electronic coupling synergistically. To improve the mobility further, a novel series of cations containing [BnPhIM-oOMe]+, [BnPhIM-mOMe]+, and [BnPhIM-pOMe]+ has been designed based on the outstanding properties of [BnPhIM]+. Combining the novel designed cations with [BF4]− and [B(CN)4]−, it is observed that [BnPhIM-pOMe]:[B(CN)4] causes PEDOT to assemble with well-ordered π–π stacking. Assessments rationalize that it could serve as a potential candidate for application in PEDOT-based electronics, since it shows similar interface electronic coupling and has a 35–43% improvement in PEDOT mobility compared to the excellent reference [BnPhIM]:[BF4].

Nano-porous electrodes combined with ionic liquids (ILs) are widely favored to promote the energy density of supercapacitors. However, this is always accompanied by the reduced power density, especially considering the high viscosity and large steric hindrance of ILs. Here, we use computational simulations coupled with the equivalent circuit model to quantify the charging process and overall performance of the IL-based supercapacitor. We find that the ions in the electrode with ionophobic pores display a new charging mechanism under a threshold potential, namely co-ion adsorption, which has been ignored before. This identified abnormal charging process can not only efficiently enhance the differential capacitance but also remarkably speed up the charging dynamics. Meanwhile, the pores with various sizes and lengths in the electrode demonstrate the same tendency, reflecting the relative universality of the collaborative enhancement of the co-ion adsorption process. Furthermore, the quantitative relation between charging time/capacitance and electric voltage/ionophobic properties is further obtained to evaluate the critical conditions for synergistically improving the energy density and power density of supercapacitors. These findings may advance the understanding of charging mechanisms in porous electrodes and manifest that the ionophobicity is one important factor in the rational design of supercapacitors with ILs or other electrochemical devices in the field of chemical engineering.

In recent years, more and more deep neural network methods have been used in the forecasting research of multivariate time series. Comparing to the traditional methods such as autoregressive models, methods based on neural networks have achieved superior results. However, the sequence data comes from all aspects, and the data contains long-term and short-term models, which is not a small challenge for data prediction research. We builds a model based on a deep neural network, and uses a convolutional network and a recurrent network in the long-term sequence data input and short-term sequence data input of the model. Convolutional networks are mainly used to extract short-term patterns in sequence data, and recurrent networks are mainly used to extract long-term patterns in sequence data. In addition, in order to solve the problem that the output of the neural network is not sensitive to the change of the input scale, we also added an autoregressive network to the model. When constructing the input of the model, we use the corresponding period characteristics to construct the two input of the model for different datasets: long-term historical data and short-term historical data. Our model has achieved better results than traditional prediction models on four public data sets: out of 32 indicators in 8 methods, 24 optimal results have been achieved.

The brushless DC motor (BLDCM) will be suffered the impact of chaos at the certain conditions. Therefore, This paper proposes a nonlinear state control method to suppress and control the emergence of chaotic motion based on the Lyapunov stability theory. Firstly, We analyze the dynamic characteristics of the state equation of BLDCM system, and prove that it will appear chaos phenomenon at some certain parameters. Finally, the nonlinear feedback controller is designed based on the Lyapunov stability theory, and is proved that the control method can make the system asymptotically stable to the equilibrium point. And further, simulation results are given to verify that the proposed method can be successfully used to control a chaotic BLDCM and make BLDCM stable quickly.

Artificial solid electrolyte interphase (SEI) protective layer has been widely applied to protect lithium (Li) metal anode. However, few attentions have been paid to interface contact between artificial SEI and Li metal. Here, we develop a polymer-inorganic gradient SEI (PIG-SEI) layer on Li, which consists of the outer polymer rich layer of PEGDA-co-VC and inner inorganic nanoparticles rich layer of LiF, Li3N and Cu. The PIG-SEI protected Li metal anode can not only improve interface contact between PIG-SEI layer and Li metal and the Li-ion conductivity of SEI layer but also increase the flexibility and mechanical strength. As a result, the PIG-SEI protected Li metal anode enable Li || Li symmetric cells to maintain a stable overpotential of 20 mV at a capacity of 2 mAh cm−2 over 2500 h, and enable Li || LiFePO4 and Li || LiNi0.8Co0.1Mn0.1O2 cell to capacity of 122 mAh g−1 and 123 mAh g−1 at 0.5 C for 500 cycles under lean carbon-ate-based electrolyte (Li || Li: 5.0 µL mAh−1, Li || LiFePO4 : 14.3 µL mAh−1, Li || LiNi0.8Co0.1Mn0.1O2 : 14.4 µL mAh−1). It is believed that our gradient-layer protected Li metal anode opens up new idea for the practical applications of next-generation high-energy-density Li metal batteries.

The low-temperature oxidation of coal includes processes such as coal-oxygen reactions and pyrolysis. As heat generated from coal-oxygen reaction is the fundamental driver of coal spontaneous combu...

Cause marketing (CM) has become a prevalent form of generating support for a cause while netting valuable visibility for both the firm and the environmental nonprofit organisation. In this paper, t...