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Magnetic topological states of matter provide a fertile playground for emerging topological physics and phenomena. The current main focus is on materials whose magnetism stems from 3d magnetic transition elements, e.g., MnBi2Te4, Fe3Sn2 and Co3Sn2S2. In contrast, topological materials with the magnetism from rare earth elements remain largely unexplored. Here we report rare earth antiferromagnet GdAuAl4Ge2 as a candidate magnetic topological metal. Angle resolved photoemission spectroscopy and first-principles calculations have revealed multiple bulk bands crossing the Fermi level and pairs of low energy surface states. According to the parity and Wannier charge center analyses, these bulk bands possess nontrivial Z2 topology, establishing a strong topological insulator state in the nonmagnetic phase. Furthermore, the surface band pairs exhibit strong termination dependence which provides insight into their origin. Our results suggest GdAuAl4Ge2 as a rare earth platform to explore the interplay between band topology, magnetism and f electron correlation, calling for further study targeting on its magnetic structure, magnetic topology state, transport behavior and microscopic properties.

An optical encryption (OE) scheme based on the spread spectrum ghost imaging (SSGI), named SSGI-OE, is proposed to obtain a high security with a smaller key. In the scheme, the randomly selected row number of a Hadamard matrix of order $N$ is used as the secure key, and shared with the authorized user, Bob, through a private channel. Each corresponding row vector of the order $N$ Hadamard matrix is then used as the direct sequence code to modulate a speckle pattern for the ghost imaging system, and an image is encrypted with the help of the SSGI. The measurement results from the bucket detector, named ciphertext, are then transmitted to Bob through a public channel. The illuminating speckle patterns are also shared with Bob by the public channel. With the correct secure key, Bob could reconstruct the image with the aid of the SSGI system, whereas, the unauthorized user, Eve, could not obtain any useful information of the encrypted image. The numerical simulations and experimental results show that the proposed scheme is feasible with a higher security and a smaller key. For the $32 \times 32$ pixels image, the number of bits sent from Alice to Bob by using SSGI-OE ($M=1024,N=2048$) scheme is only $0.0107$ times over the computational ghost imaging optical encryption(CGI-OE) scheme. When the eavesdropping ratio (ER) is less than 40%, the eavesdropper cannot acquire any information of the encrypted image. The extreme circumstance for the proposed SSGI-OE scheme is also discussed, where the eavesdropper begins to extract the information when ER is up to 15%.

The simple kagome-lattice band structure possesses Dirac cones, flat band, and saddle point with van Hove singularities in the electronic density of states, facilitating the emergence of various electronic orders. Here we report a titanium-based kagome metal CsTi3Bi5 where titanium atoms form a kagome network, resembling its isostructural compound CsV3Sb5. Thermodynamic properties including the magnetization, resistance, and heat capacity reveal the conventional Fermi liquid behavior in the kagome metal CsTi3Bi5 and no signature of superconducting or charge density wave (CDW) transition anomaly down to 85 mK. Systematic angle-resolved photoemission spectroscopy measurements reveal multiple bands crossing the Fermi level, consistent with the first-principles calculations. The flat band formed by the destructive interference of hopping in the kagome lattice is observed directly. Compared to CsV3Sb5, the van Hove singularities are pushed far away above the Fermi level in CsTi3Bi5, in line with the absence of CDW. Furthermore, the first-principles calculations identify the nontrivial Z2 topological properties for those bands crossing the Fermi level, accompanied by several local band inversions. Our results suppose CsTi3Bi5 as a complementary platform to explore the superconductivity and nontrivial band topology.

Orbital angular momentum (OAM) has the characteristics of mutual orthogonality between modes, and has been applied to underwater wireless optical communication (UWOC) systems to increase the channel capacity. In this work, we propose a diffractive deep neural network (DDNN) based OAM mode recognition scheme, where the DDNN is trained to capture the features of the intensity distribution of the OAM modes and output the corresponding azimuthal indices and radial indices. The results show that the proposed scheme can recognize the azimuthal indices and radial indices of the OAM modes accurately and quickly. In addition, the proposed scheme can resist weak oceanic turbulence (OT), and exhibit excellent ability to recognize OAM modes in a strong OT environment. The DDNN-based OAM mode recognition scheme has potential applications in UWOC systems.

Nanotopography can promote osseointegration, but how bone marrow mesenchymal stem cells (BMMSCs) respond to this physical stimulus is unclear. Here, we found that early exposure of BMMSCs to nanotopography (6 h) caused mitochondrial fission rather than fusion, which was necessary for osseointegration. We analyzed the changes in mitochondrial morphology and function of BMMSCs located on the surfaces of NT100 (100 nm nanotubes) and ST (smooth) by super-resolution microscopy and other techniques. Then, we found that both ST and NT100 caused a significant increase in mitochondrial fission early on, but NT100 caused mitochondrial fission much earlier than those on ST. In addition, the mitochondrial functional statuses were good at the 6 h time point, this is at odds with the conventional wisdom that fusion is good. This fission phenomenon adequately protected mitochondrial membrane potential (MMP) and respiration and reduced reactive oxygen species. Interestingly, the MMP and oxygen consumption rate of BMMSCs were reduced when mitochondrial fission was inhibited by Mdivi-1(Inhibition of dynamin-related protein 1 fission) in the early stage. In addition, the effect on osseointegration was significantly worse, and this effect did not improve with time. Taken together, the findings indicate that early mitochondrial fission plays an important role in nanotopography-mediated promotion of osseointegration, which is of great significance to the surface structure design of biomaterials.

Objective. Patient-dependent seizure detection based on intracranial electroencephalography (iEEG) has made significant progress. However, due to the difference in the locations and number of iEEG electrodes used for each patient, patient-independent seizure detection based on iEEG has not been carried out. Additionally, current seizure detection algorithms based on deep learning have outperformed traditional machine learning algorithms in many performance metrics. However, they still have shortcomings of large memory footprints and slow inference speed. Approach. To solve the above problems of the current study, we propose a novel lightweight convolutional neural network model combining the Convolutional Block Attention Module (CBAM). Its performance for patient-independent seizure detection is evaluated on two long-term continuous iEEG datasets: SWEC-ETHZ and TJU-HH. Finally, we reproduce four other patient-independent methods to compare with our method and calculate the memory footprints and inference speed for all methods. Main results. Our method achieves 83.81% sensitivity (SEN) and 85.4% specificity (SPE) on the SWEC-ETHZ dataset and 86.63% SEN and 92.21% SPE on the TJU-HH dataset. In particular, it takes only 11 ms to infer 10 min iEEG (128 channels), and its memory footprint is only 22 kB. Compared to baseline methods, our method not only achieves better patient-independent seizure detection performance but also has a smaller memory footprint and faster inference speed. Significance. To our knowledge, this is the first iEEG-based patient-independent seizure detection study. This facilitates the application of seizure detection algorithms to the future clinic.

All-inorganic cesium lead halide CsPbX3 (X = Cl, Br, I) perovskite quantum dots (PQDs) have shown promising potential in current Mini/Micro-LED display applications due to their excellent photoluminescence performance. However, lead ions in PQDs are easily to leak owing to the unstable structure of PQDs, which hinders their commercial applications. Herein, we adopt Rb+ ions co-doping strategy to regulate the doping characteristics of Mn2+ ions in CsPbCl3 PQDs. The synthesized CsPbCl3:(Rb+, Mn2+) PQDs possess enhanced photoluminescence quantum yield of 71.1% due to the reduction of intrinsic defect states and Mn–Mn or Mn-traps in co-doped PQDs. Moreover, the white light emission of CsPb(Cl/Br)3:(Rb+, Mn2+) PQDs is achieved by anion exchange reaction and the constructed WLED exhibits the CIE coordinate of (0.33, 0.29) and the correlated color temperature of 5497 K. Benefiting from the substitution strategy, these doped CsPbX3 PQDs can be widely used as fluorescence conversion materials for the construction of Mini/Micro-LED.

Electroencephalography (EEG) is a bio-signal used in various approaches such as clinical diagnosis. The analysis aims to investigate the validity of EEG signal detection after mTBI which refers to mild traumatic brain injury. Although EEG does not directly present features that could be found within mTBI, by utilizing the processing method of CWT (Continuous Wavelet Transform) and CNN deep learning which will be mentioned, the resulted accuracy reached 91.29%. This study indicates that the proposed CWT-CNN method may have a potential usage in the identification, classification, and monitoring of mTBI patients.

The asymmetry of flow separation inside the nozzle with large expansion ratio is the main factor for the generation of side-load in the engine, so the accurate prediction of the flow separation is of great significance. The turbulence model is the key to the prediction, but in different scenarios, the performance of the turbulence model can introduce huge uncertainties. In this paper, a typical thrust-optimized nozzle (VOLVO-S1) is simulated and analyzed for three widely used turbulence models: SST k - ω 、 RNG k - ε and Spalart-Allmaras model. The results show that all these models can effectively predict the mode of shock separation phenomenon. The comprehensive performance of SST k - ω is the best; The Spalart-Allmaras model has better prediction performance under low pressure ratio, and the RNG k - ε model has better prediction effect under high pressure ratio.

We propose a new full color ghost imaging scheme using both time and code division multiplexing technologies. In the scheme, the speckle patterns of three colors (red, green and blue) are modulated with different time slots and codes. The light intensity is sampled by one bucket detector. Then based on the modulated time slots and codes, we can effectively and simultaneously extract three detection component signals corresponding to three color components of objects from the sampling signal of the bucket detector. Finally, three component images resulting from the three component detection signals can be synthesized into a full color image. The experimental results verify the feasibility of our scheme under the limit of the number of time slots and codes. Moreover, our scheme reduces the number of bucket detectors and can realize high quality imaging even in a noisy environment.

Hexagonal boron nitride/graphene (hBN/G) vertical heterostructures have attracted extensive attention, owing to the unusual physical properties for basic research and electronic device applications. Here we report a facile deposition-segregation technique to synthesize hBN/G heterostructures on recyclable platinum (Pt) foil via low pressure chemical vapor deposition. The growth mechanism of the vertical hBN/G is demonstrated to be the surface deposition of hBN on top of the graphene segregated from the Pt foil with pre-dissolved carbon. The thickness of hBN and graphene can be controlled separately from sub-monolayer to multilayer through the fine control of the growth parameters. Further investigations by Raman, scanning Kelvin probe microscopy and transmission electron microscope show that the hBN/G inclines to form a heterostructure with strong interlayer coupling and with interlayer twist angle smaller than 1.5°. This deposition-segregation approach paves a new pathway for large-scale production of hBN/G heterostructures and could be applied to synthesize of other van der Waals heterostructures.

The antiferromagnetic (AFM) interlayer coupling effective field in a ferromagnetic/non-magnetic/ferromagnetic (FM/NM/FM) sandwich structure, as a driving force, can dramatically enhance the ferromagnetic resonance (FMR) frequency. Changing the non-magnetic spacer thickness is an effective way to control the interlayer coupling type and intensity, as well as the FMR frequency. In this study, FeCoB/Ru/FeCoB sandwich trilayers with Ru thickness (t Ru) ranging from 1 Å to 16 Å are prepared by a compositional gradient sputtering (CGS) method. It is revealed that a stress-induced anisotropy is present in the FeCoB films due to the B composition gradient in the samples. A t Ru-dependent oscillation of interlayer coupling from FM to AFM with two periods is observed. An AFM coupling occurs in a range of 2 Å ≤ t Ru ≤ 8 Å and over 16 Å, while an FM coupling is present in a range of t Ru < 2 Å and 9 Å ≤ t Ru ≤ 14.5 Å. It is interesting that an ultrahigh optical mode (OM) FMR frequency in excess of 20 GHz is obtained in the sample with t Ru = 2.5 Å under an AFM coupling. The dynamic coupling mechanism in trilayers is simulated, and the corresponding coupling types at different values of t Ru are verified by Layadi’s rigid model. This study provides a controllable way to prepare and investigate the ultrahigh FMR films.

We propose a phase-matching quantum key distribution (PM-QKD) protocol based on orbital angular momentum (OAM) to exceed the linear key-rate bound without quantum repeater in the paper, named OAM-PM-QKD protocol, where the coherent state consisting of OAM with opposite topological charges is used as the information carrier. With the equivalent entanglement distillation model, we analyze its security and then derive its key generation rate. The numerical simulation results show that the proposed OAM-PM-QKD protocol is able to exceed the linear key-rate bound when the transmission distance exceeds 230 km, and the maximum secure transmission distance is also longer than those of original PM-QKD protocol due to no misalignment in the basis. Furthermore, the influence of the atmospheric turbulence (AT) on the key generation rate is also discussed. The stronger the strength of AT is, the shorter the transmission distance is.

Ghost imaging (GI) offers great potential with respect to conventional imaging techniques. However, there are still some obstacles for reconstructing images with high quality, especially in the case that the orthogonal measurement matrix is impossible to construct. In this paper, we propose a new scheme based on the orthogonal-triangular (QR) decomposition, named QR decomposition ghost imaging (QRGI) to reconstruct a better image with good quality. In the scheme, we can change the randomly non-orthogonal measurement matrix into orthonormal matrix by performing QR decomposition in two cases. (1) When the random measurement matrix is square, it can be firstly decomposed into an orthogonal matrix Q and an upper triangular matrix R . Then let the off-diagonal values of R equal to 0.0, the diagonal elements of R equal to a constant k, where k is the average of all values of the main diagonal, so the resulting measurement matrix can be obtained. (2) When the random measurement matrix is with full rank, we firstly compute its transpose, and followed with above QR operation. Finally, the image of the object can be reconstructed by correlating the new measurement matrix and corresponding bucket values. Both experimental and simulation results verify the feasibility of the proposed QRGI scheme. Moreover, the results also show that the proposed QRGI scheme could improve the imaging quality comparing to traditional GI (TGI) and differential GI (DGI). Besides, in comparison with the singular value decomposition ghost imaging (SVDGI), the imaging quality and the reconstruction time by using QRGI are similar to those by using SVDGI, while the computing time (the time consuming on the light patterns computation) is substantially shortened.

We propose a method for imaging a periodic moving/state-changed object based on computational ghost imaging with Hadamard speckle patterns and a slow bucket detector, named as PO-HCGI. In the scheme, speckle patterns are produced from a part of each row of a Hadamard matrix. Then, in each cycle, multiple speckle patterns are projected onto the periodic moving/state-changed object, and a bucket detector with a slow sampling rate records the total intensities reflected from the object as one measurement. With a series of measurements, the frames of the moving/state-changed object can be obtained directly by the second-order correlation function based on the Hadamard matrix and the corresponding bucket detector measurement results. The experimental and simulation results demonstrate the validity of the PO-HCGI. To the best of our knowledge, PO-HCGI is the first scheme that can image a fast periodic moving/state-changed object by computational ghost imaging with a slow bucket detector.

The transmission loss of photons during quantum key distribution (QKD) process leads to the linear key rate bound for practical QKD systems without quantum repeaters. Phase matching quantum key distribution (PM-QKD) protocol, an novel QKD protocol, can overcome the constraint with a measurement-device-independent structure, while it still requires the light source to be ideal. This assumption is not guaranteed in practice, leading to practical secure issues. In this paper, we propose a modified PM-QKD protocol with a light source monitoring, named PM-QKD-LSM protocol, which can guarantee the security of the system under the non-ideal source condition. The results show that our proposed protocol performs almost the same as the ideal PM-QKD protocol even considering the imperfect factors in practical systems. PM-QKD-LSM protocol has a better performance with source fluctuation, and it is robust in symmetric or asymmetric cases.

Single crystals of PrFe2Ga8 were successfully grown by using Ga self-flux. PrFe2Ga8 crystallizes in the CaCo2Al8-type orthorhombic structure with the space group Pbam (no. 55). By combining the results from the magnetic-susceptibility, specific-heat, and resistivity measurements, we show that PrFe2Ga8 exhibits a magnetic order at 14 K. For H // c, the antiferromagnetic order can be suppressed by magnetic fields. However, the magnetic order is robust against magnetic fields for H ⊥ c. Our results provide basic physical properties of PrFe2Ga8 and will help to further understand the magnetism in this system.

Despite the various techniques developed for the transfer of large area graphene grown by chemical vapor deposition (CVD), the conventional polymethylmethacrylate (PMMA) transferring technique has been widely applied in laboratories due to its convenience and economical cost. However, the complete removal of PMMA on graphene surface has become a troublesome, and the PMMA residue could degrade the properties of graphene significantly. We report here a facile water assisted technique to directly peel off the PMMA layer over centimeter-sized CVD graphene film for the first time. No organic solvents are involved in the whole transfer process. The transferred graphene film is clean and intact over large area because of the cooperative effect of the capillary force and the van der Waals force which facilitates the conformal contact between graphene film and the substrate. Various types of graphene samples (i.e. monolayer, multilayer, and incomplete domains) can be easily transferred to diverse substrates including silicon wafer, sapphire, and quartz with good integrity. The transferred graphene film is of high cleanliness, and the graphene transistors show higher carrier mobility and lower level of p-type doping comparing to the conventional wet transfer technique.

Nowadays, identity protection has turned into a fundamental demand for online activities. Currently, the present quantum anonymous communication protocols mostly rely on multi-entanglement. In this paper, we propose an anonymous communication protocol for anonymous sender by using single-particle states. The protocol can be extended to a communication protocol where the sender and receiver are fully anonymous with the message kept secret. In terms of security, our protocol is designed to comply with the technique of collective detection. Compared to the step-by-step detection, collective detection, in which the participants perform detection only once, reduces the complexity of the protocol to some extent. Moreover, we analytically demonstrate the security of the protocol in the face of active attacks. Any active attack employed by an external or internal attacker cannot reveal any useful information about the sender’s identity. Meanwhile, any malicious behavior will be detected by honest participants.

High surface area nickel oxide nanowires (NiO NWs), Fe-doped NiO NWs andα-Fe2O3/Fe-doped NiO NWs were synthesized with nanocasting pathway, and then the morphology, microstructure and components of all samples were characterized with XRD, TEM, EDS, UV-vis spectra and nitrogen adsorption-desorption isotherms. Owing to the uniform mesoporous template, all samples with the same diameter exhibit the similar mesoporous-structures. The loadedα-Fe2O3nanoparticles should exist in mesoporous channels between Fe-doped NiO NWs to form heterogeneous contact at the interface of n-typeα-Fe2O3nanoparticles and p-type NiO NWs. The gas-sensing results indicate that Fe-dopant andα-Fe2O3-loading both improve the gas-sensing performance of NiO NWs sensors.α-Fe2O3/Fe-doped NiO NWs sensors presented the highest response to 100 ppm ethanol gas (55.264) compared with Fe-doped NiO NWs (24.617) and NiO NWs sensors (3.189). The donor Fe-dopant increases the ground state resistance and the absorbed oxygen content in air.α-Fe2O3nanoparticles in electron depletion region result in the increasing resistance in ethanol gas and decreasing resistance in air. In this way,α-Fe2O3/Fe-doped NiO NWs sensor presents the excellent gas-sensing performance due to the formation of heterogeneous contact at the interface.

According to the structural characteristics of the fixed-cylinder hydro-pneumatic suspension, the force transmission and the construction of the theoretical model were discussed. The non-linear correspondence of the force between the piston and the road wheel was clarified through analytical deduction, and the formula for calculating the stiffness of the suspension was given. The influence factors of suspension leverage ratio and elastic force were simulated and analysed by programming, the conclusions drawn provided ideas for the design of zero stiffness suspension near the equilibrium position.

The titanomagnetites (Fe2-xTixO4,x⩽ 1) are a family of reducible spinel-structure oxides of interest for their favorable magnetic, catalytic, and electrical transport properties. To understand the stability of the system during low temperature deposition, epitaxial thin films of Fe2TiO4were deposited by molecular beam epitaxy (MBE) on MgO(001) at 250-375 °C. The homogeneous incorporation of Ti, Fe valence state, and film morphology were all found to be strongly dependent on the oxidation conditions at the low substrate temperatures employed. More oxidizing conditions led to phase separation into epitaxial, faceted Fe3O4and rutile TiO2. Less oxidizing conditions resulted in polycrystalline films that exhibited Ti segregation to the film surface, as well as mixed Fe valence (Fe3+, Fe2+, Fe0). A narrow window of intermediate oxygen partial pressure during deposition yielded nearly homogeneous Ti incorporation and a large fraction of Fe2+. However, these films were poorly crystallized, and no occupation of tetrahedral sites in the spinel lattice by Fe2+was detected by x-ray magnetic circular dichroism at the Fe L-edge. After vacuum annealing, a small fraction of Fe2+was found to occupy tetrahedral sites. Comparison of these results with previous work suggests that the low temperature deposition conditions imposed by use of MgO substrates limits the incorporation of Ti into the spinel lattice. This work suggests a path towards obtaining stoichiometric, well-crystallized Fe2TiO4by MBE by utilizing high substrate temperature and low oxygen partial pressure during deposition on thermally stable substrates.

Interfacial structure evolution and degradation are critical to the electrochemical performance of LiCoO2 (LCO), the most widely studied and used cathode material in lithium ion batteries. To understand such processes requires precise and quantitative measurements. Herein, we use well-defined epitaxial LCO thin films to reveal the interfacial degradation mechanisms. Through our systematical investigations, we find that surface corrosion is significant after forming the surface phase transition layer, and the cathode electrolyte interphase (CEI) has a double layer structure, an inorganic inner layer containing CoO, LiF, LiOH/Li2O and Li x PF y O z , and an outmost layer containing Li2CO3 and organic carbonaceous components. Furthermore, surface cracks are found to be pronounced due to mechanical failures and chemical etching. This work demonstrates a model material to realize the precise measurements of LCO interfacial degradations, which deepens our understanding on the interfacial degradation mechanisms.

This article is aimed at the requirements of a cigarette factory’s off-site technical transformation task, and it needs to transfer part of the stem and expanded silk produced by the new factory to the old factory. Therefore, it is necessary to construct a set of fully automatic carton packing system for shredded tobacco to improve production efficiency and reduce labor intensity. The system is divided into mechanical equipment layer, equipment control layer and production monitoring layer. The mechanical equipment layer is the design of the process flow between the various machinery and equipment of the tobacco packing production line; the equipment control layer is based on the STMicroelectronics32(STM32) single-chip microcomputer as the control core, through Modbus The protocol controls each device and performs data transmission, and communicates with the upper computer through the industrial Ethernet and Modbus Transmission Control Protocol(Modbu TCP) protocol; the production monitoring layer is based on the Qt programming tool for interface design and data transmission with the lower computer, and the relevant data is stored in My Structured Query Language (MySQL) In the database. This solution realizes the automation, networking and intelligence of industrial production lines, liberating manpower and improving efficiency.

In order to eliminate the digital gap between equipment control and production information management, a smart factory remote control and data analysis system based on a cloud-fog hybrid computing model is proposed. Alibaba Cloud Server serves as the cloud computing layer to provide data storage and services, and the Internet of Things platform serves as the fog terminal. The computing layer completes data filtering and system early warning. The system consists of five parts: perception layer, gateway layer, platform layer, application layer and persistence layer. Each layer is designed and analyzed. The dead zone-adaptive swing door trending algorithm is used for data compression, and the system pressure test experiment and the data compression accuracy test experiment are completed. The experimental results show that this system improves the control of data in the production process, reduces the amount of data storage, and has high system compatibility to meet actual production needs.

Under applying the gradient electromagnetic field of 2100Gs-3300Gs, the explosion pressure and the propagation velocity of the explosion flame of 5% propane/air premixed gases were studied experimentally. The experimental results showed that the gradient electromagnetic field suppressed the explosion overpressure and explosion flame propagation velocity. When applied the gradient electromagnetic field, the peak propane explosion pressure decreased by 26KPa and the explosion flame propagation velocity decreased by 1.54269m/s. In other words, the gradient electromagnetic field suppressed the increase of pressure shock waves and light waves. Through the numerical simulation of propane explosion reaction, it is inferred that electromagnetic field mainly inhibits propane explosion pressure and explosion flame propagation speed by affecting the reactions of • H, • O and • OH radicals.

Anonymous voting is often one decision-making choice in many democracies. Facing the security threats from quantum computers, classical anonymous voting protocols based on computational complexity hypothesis have innovated to quantum anonymous voting protocols based on quantum mechanics. In this paper, we propose a quantum anonymous voting protocol by using high-dimension single particles. With the help of EA and T, the construction of our protocol makes each legitimate voter cast only one ballot, and all ballots open in a quite random rearrangement. Each voter can anonymously trace his/her vote by a private position index, thus our protocol achieving the precious properties of eligibility, privacy, no-reusability, verifiability and fairness. We also analyze that the protocol can successfully resist attacks from external eavesdroppers and internal participants, ensuring that our voting protocol is secure under ideal conditions. Designing mature quantum anonymous voting protocols is challenging.

Earth-abundant nickel-containing perovskite oxides (ANiO3) are highly active materials for the oxygen evolution reaction (OER). The strong nickel-oxygen (Ni–O) covalency, tunable by A-site chemical substitution, contributes to both bulk and surface material properties like the formation of oxygen vacancies (v •• O ) and OER activity. Here we quantify the coverage of OER relevant adsorbates on a series of La1−x Sr x NiO3−δ (LSNO, 0 ⩽ x ⩽ 0.5) epitaxial thin films exposed to humid environments by ambient pressure x-ray photoelectron spectroscopy. While all LSNO film compositions investigated here have comparable hydroxide coverages at the relative humidities (RHs) probed (1.5 × 10−5 – 0.2%RH), the amount of under-coordinated surface oxygen increases notably with Sr content. We interpret differences in the free energy of adsorption (ΔG ads,i ) of these OER intermediates, inferred from adsorption isotherms, in the context of proposed v •• O -mediated OER mechanisms, consistent with the pH-dependent OER activity observed here for LSNO. We find that Sr incorporation enhances the affinity of LSNO surfaces for these under-coordinated oxygen species, in line with calculations in the literature.

We present a ghost handwritten digit recognition method for the unknown handwritten digits based on ghost imaging (GI) with deep neural network, where a few detection signals from the bucket detector, generated by the cosine transform speckle, are used as the characteristic information and the input of the designed deep neural network (DNN), and the output of the DNN is the classification. The results show that the proposed scheme has a higher recognition accuracy (as high as 98% for the simulations, and 91% for the experiments) with a smaller sampling ratio (say 12.76%). With the increase of the sampling ratio, the recognition accuracy is enhanced. Compared with the traditional recognition scheme using the same DNN structure, the proposed scheme has slightly better performance with a lower complexity and non-locality property. The proposed scheme provides a promising way for remote sensing.

Based on the Euler-Euler-Lagrangian framework, the Euler-Euler two-fluid model coupled with population balance model (PBM) and the Discrete Phase Model (DPM) model were used to simulate the gas-liquid-solid three phase dynamic behavior in the laboratory bubble column. The non-Newtonian properties of the liquid phase was considered in the numerical simulation, and the cases with different numerical models were discussed. It is found that the peak value velocity of liquid phase decrease due to the solid phase. The gas holdup remains almost the same in different cases with or without solid phase. There is no obvious periodic oscillation plume in non-Newtonian fluid. The interaction between solid and liquid has an effect on the flow field, gas distribution and viscosity distribution. The flow field calculated by CFD+PBM+DPM model forms three obvious vortices, while the symmetrical vortex is formed by CFD+PBM+DPM model, which is located on both sides of the bubble column. The distribution of dynamic viscosity simulated by different numerical models is basically the same in vary cases.

Cast-in-place concrete lining, which is the major structure of a tunnel with composite or monolithic lining, requires high safety, durability and waterproof performance. The prevention and control of lining concrete cracks are of great concern. However, the temperature and shrinkage cracks in the arch and wall of a cast-in-place concrete lining are common construction quality defects in practical cases. This contribution presents the changing features of temperature crack widths in responding to the temperature variation with seasons in several cast-in-place final ling panels, where there are no waterproof and drainage sheets in their composite linings. The crack width changing features imply that the constraints to the temperature drop and shrinkage deformation of the concrete in its arch and wall in construction stage still work in the period of post-construction. Considering the cracks beyond the planned allowable values, the information on the width changing features presents clue to determine the rule on the occurring and developing of the temperature and shrinkage cracks in the cast-in-place lining concrete, as well as crack resistance design and construction quality control.

In order to optimize the extraction process of fucoidan from dealginated kelp waste. On the basis of single-factor experiments, Box-Behnken design was evaluated to study different variables of pH, extraction temperature and extraction time on fucoidan yield. By solving the regression equations and analyzing 3-D plots, the optimum conditions were at pH4.9, liquid/material ratio of 20:1 mL/g, extraction temperature of 73°C, and extraction time of 4 h. Under these conditions, the fucoidan yield of dealginated Kelp waste was 1.63 ± 0.07%, which were in good agreement with the predicted values. It is the first report of fucoidan extraction from dealginated kelp waste and the results provides a basis for further purification and application of fucoidan.

Variable Reluctance resolver as a shaft position detection unit has been wildly used in harsh environments because of high reliability. This paper uses the finite element method to analyze the influence of the harmonic components in the magnetic field on the accuracy of the resolver, and proposes a method to add slots at stator combined with optimizing the output winding distributions to reduce the harmonic content in the output voltage. Finally, the sinusoidal of output voltage turned out to be improved and the resolver met the measurement accuracy of ±30’.

The Internet of Things technology is widely used in many industries and fields, including smart production and management, smart transportation and environmental protection, industrial monitoring and social security. Community construction is turning to smart communities. The construction of smart communities mainly uses network communication system facilities to realize the integrated networking of community residents and public facilities, to carry out information management of community residents, living and service facilities, and to improve the living environment by using modern technical measures. Aiming at the decentralization of IoT technology and smart community fusion products, an integrated information system platform needs to be built. In this article, the overall design framework of smart communities based on Internet of Things technologies is studied, and the smart community information management platform is divided into several main parts; Each part as Subsystem, discusses the basic functions of the subsystem, and finally realizes the intelligent construction of the smart community as a whole. We start work from the reality of the systematic construction of smart communities, combining with the latest Internet of Things technology, research and build a smart community information management platform with a unified architecture to achieve unified management and scheduling of smart community sub-products.

In order to accurately evaluate the real-time consumption capacity of new energy considering the dynamic coordination of network sources in real-time scale, a new energy real-time consumption capacity evaluation model considering the dynamic constraints of network sources is established. Firstly, according to the operation plan of thermal power unit, the transmission plan of tie line, the regulation margin of transformer ratio and the capacity of each node’s reactive device, the dynamic constraint of network source is set. Then, according to the grid parameters, the real-time prediction of new energy station operation and the real-time prediction of each node load demand, the line power flow security, node power balance, node voltage security and new energy station operation constraints are set. Finally, two optimization objectives of new energy active power maximum and minimum consumption are set up, and a new energy real-time consumption capacity evaluation model considering the dynamic constraints of network sources is established, which takes the active and reactive power of thermal power unit, the active and reactive power of tie line, the transformer transformation ratio, the reactive capacity of reactive device switching, and the active and reactive power of new energy as decision variables. The validity of the model is verified by 4-node system.

In order to solve the problem of evading air-to-air missiles of UCAV in autonomous air combat, the flight dynamics model and 3-dimensional guidance trajectory model based on proportional guidance were established and performance constraint conditions of missiles were constructed. According to the definition of basic maneuver library, 72 kinds of avoidance maneuvers were constructed. All 72 avoidance maneuvers were simulated while UCAV was at different relative yaw angles and relative pitch angles, and the optimal avoidance maneuvers under the corresponding conditions were selected out. Training samples and test samples were constructed by utilizing the acquired data, and the neural network for generating control parameters was trained. Under different conditions, neural network method and random selection method were simulated. The results show that the success rate of escape of the proposed method is higher and the time cost of generating the control parameters is less, which meets the requirements of effectiveness and real-time.

We propose a compressed ghost imaging scheme based on differential speckle patterns, named CGI-DSP. In the scheme, a series of bucket detector signals are acquired when a series of random speckle patterns are employed to illuminate an unknown object. Then the differential speckle patterns (differential bucket detector signals) are obtained by taking the difference between present random speckle patterns (present bucket detector signals) and previous random speckle patterns (previous bucket detector signals). Finally, the image of object can be obtained directly by performing the compressed sensing algorithm on the differential speckle patterns and differential bucket detector signals. The experimental and simulated results reveal that CGI-DSP can improve the imaging quality and reduce the number of measurements comparing with the traditional compressed ghost imaging schemes because our scheme can remove the environmental illuminations efficiently.

Microcrystalline diamond (MCD) films with different grain sizes ranging from 160 nm to 2200 nm are prepared by using a hot filament chemical vapor deposition (HFCVD) system, and the influences of grain size and structural features on optical properties are investigated. The results show that the film with grain size in a range of 160 nm–310 nm exhibits a higher refractive index in a range of (2.77–2.92). With grain size increasing to 620±300 nm, the refractive index shows a value between 2.39 and 2.47, approaching to that of natural diamond (2.37–2.55), and a lower extinction coefficient value between 0.08 and 0.77. When the grain size increases to 2200 nm, the value of refractive index increases to a value between 2.66 and 2.81, and the extinction coefficient increases to a value in a range of 0.22–1.28. Visible Raman spectroscopy measurements show that all samples have distinct diamond peaks located in a range of 1331 cm−1–1333 cm−1, the content of diamond phase increases gradually as grain size increases, and the amount of trans-polyacetylene (TPA) content decreases. Meanwhile, the sp2 carbon clusters content and its full-width-at-half-maximum (FWHM) value are significantly reduced in MCD film with a grain size of 620 nm, which is beneficial to the improvement of the optical properties of the films.

White light-emitting diodes (WLEDs) based on all-inorganic perovskite CsPbX3 (X = Cl, Br, I) quantum dots (QDs) have attracted great attention, which rely on mixing several colors of perovskites. However, this inevitably leads to a non-uniform light distribution and serious light loss. Here, a novel strategy was demonstrated to obtain white emission by combining the orange and blue emission from CsPb/Mn(Cl/Br)3 QDs. Notably, highly efficient white emission with photoluminescence quantum yield (PLQY) of 94% was achieved by an anion exchange surface engineering (AESE) strategy. After the AESE treatment, the surface traps can be eliminated, resulting in improved exciton and Mn2+ emission. A prototype WLED device is fabricated, which exhibits excellent optical stability, demonstrating great potential for the perovskite QDs in the field of optoelectronics.

As optimization problems become more complex, the need of new algorithms becomes greater. In this paper, a new powerful algorithm based on nuclear reaction process, namely, nuclear reaction optimization, is proposed for numerical optimization. The NRO algorithm which includes nuclear fission and fusion phases mimics the fission and fusion processes. In the first phase, the Gaussian walk and differential evolution operators are used for modeling fission process. In the second phase, the variants of differential evolution operators are employed for modeling the ionization stage and fusion stage. Additionally, six benchmark functions and unconstrained engineering design problem are evaluated by NRO and other compared algorithms. The optimization results indicate that the NRO has presented feasibility and superiority performance.