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When trains pass through damaged switch rails, rail head damage will change wheel–rail contact states from rolling frictions to unsteady contacts, which will result in impact vibrations and threaten structural safeties. In addition, under approaching and moving away rolling contact excitations and complex wheel–rail contacts, the non-stationary vibrations make it difficult to extract and analyze impact vibrations. In view of the above problems, this paper proposes a variational-mode-decomposition (VMD)-spectral-subtraction (SS)-based impact vibration extraction method. Firstly, the time domain feature analysis method is applied to calculate the time moments that the wheels pass joints, and to correct vehicle velocities. This can help estimate and confine impact vibration distribution ranges. Then, the stationary intrinsic mode function (IMF) components of the impact vibration are decomposed and analyzed with the VMD method. Finally, impact vibrations are further filtered with the SS method. For rail head damage with different dimensions, under different velocity experiments, the frequency and amplitude features of the impact vibrations are analyzed. Experimental results show that, in low-velocity scenarios, the proposed VMD–SS–based method can extract impact vibrations, the frequency features are mainly concentrated in 3500–5000 Hz, and the frequency and peak-to-peak features increase with the increase in excitation velocities. [ABSTRACT FROM AUTHOR]

Immunohistochemical staining is a common technique to study tissue morphology and in situ protein expression. With the rise of immunotherapy, more and more markers in the tumor microenvironment have been discovered. In this paper, the multiplex immunofluorescence staining method was used to stain paraffin sections of 35 cases of gastric adenocarcinoma tissue and 35 cases of colorectal adenocarcinoma tissue and its adjacent tissue. The infiltration of CD8+ T cells and CD103+CD8+ T cells in the slices was detected by using the slice scanner to form the map and CaseViewer2.0 software analysis. The experimental results in this paper showed that compared with adjacent tissues, the infiltration degree of CD8+ T cells in gastric adenocarcinoma tissue was significantly lower (Z = 2.244 , P = 0.025 , P < 0.05), and the infiltration degree of cells was significantly lower (Z = 2.785 , P = 0.005 , P < 0.05). In gastric adenocarcinoma tissue, the infiltration of CD8+ T cells was correlated with the tumor diameter of gastric adenocarcinoma (P = 0.002). There was a statistically significant difference. The degree of CD103+CD8+ T cell infiltration was related to the survival of patients with gastric adenocarcinoma (P = 0.002) and the degree of tumor differentiation (P = 0.004). The infiltration of CD103+CD8+ T cells in gastric cancer tissue and colorectal cancer tissue is related to the survival of patients. CD103+CD8+ T cells are thought to play a role in the prognosis of gastric adenocarcinoma and colorectal adenocarcinoma. Experiments have shown that the more the CD103+CD8+ T cells, the better the prognosis of gastric adenocarcinoma and colorectal adenocarcinoma, so the prognosis of gastric adenocarcinoma and colorectal adenocarcinoma can be improved by increasing CD103+CD8+ T cells. [ABSTRACT FROM AUTHOR]

In order to reduce the ineffective evaporation of plain reservoirs in arid areas, strengthen the effective utilization of water resources, and explore effective water-saving benefit models. Research methods: Field tests were carried out with antievaporation floating balls with different coverage rates, and the water-saving rate and economic benefits under floating ball coverage were analyzed. By analyzing the frequency of different wind speeds, daily evaporation under different coverage rates, monthly evaporation inhibition rates under different coverage rates, and the cost of materials used were analyzed. The results showed that (1) during the test period, the total evaporation from the water surface of different cover groups was 149.5 mm, 122.2 mm, 100.1 mm, 81.1 mm, and 63.1 mm, respectively, and the evaporation inhibition rates of different cover groups were 18.4%, 30.8%, 43.4%, and 58.6%, respectively. (2) Comprehensive consideration of the preliminary input and output ratio of the latter determine when the float coverage rate of 50% is the optimal coverage rate, the annual water savings of 5421.86 m 3 , the annual increase in production value of 87,700 yuan, and the float in the reservoir site operation for 5 years to reach the recovery period and start to profit. (3) Based on the analysis of the economic indicators of laying floating balls in a large area of the reservoir and the calculation of the sales income and total investment, the results show that the total investment is a sensitive factor, and the project has a strong risk resistance ability. Therefore, the floating ball covering method to inhibit the ineffective evaporation of water surfaces is practical and feasible in terms of reservoir water-saving and economic benefits. [ABSTRACT FROM AUTHOR]

A new partitioned stator field modulation machine (PSFMM) with H-shape permanent magnet (HPM) excitation (HPM-PSFMM) is proposed, which is evolved from the conventional flux-switching machine (FSM) and flux-reversal machine (FRM). The proposed HPM-PSFMM combines the merits of high reliability and good heat dissipation characteristic. In addition, it exhibits high torque production with low torque ripple. Based on the theory of electrical machine operation, the FSM and FRM can be transformed into PSFMM with interior permanent magnet (IPM) and surface-mounted PM (SPM) excitation by changing the position of PM excitation, respectively. It benefits to improve space utilization and increase slot area for a large number of armature windings. For reducing the flux leakage and enhancing the flux density in air gaps, the IPM and SPM excitation are combined into HPM excitation. The iron-pole rotor between the inner and outer stators acts the role of modulator to modulate the magnetic field excited by HPM excitation to couple with the armature reaction for converting electromechanical energy. The evolution process, operating principle, and key design parameters of the proposed HPM-PSFMM are presented. Finally, using the finite element analysis (FEA), it can be proven that the proposed HPM-PSFMM has the merits of high torque production, low flux leakage, low total harmonic distortion (THD), and low torque ripple when compared to other stator-PM machines, which is a desirable choice for high stability applications. [ABSTRACT FROM AUTHOR]

A new type of hybrid magnet dual stator field modulation machine with different split ratios of stators (DSR-HMDSFMM) is proposed in this article, which has the merit of high torque density. The split teeth of stator sever as modulators to modulate air gap flux density based on the magnetic gearing effect for high torque production. The total split tooth number of inner stator is equal to that of outer stator because the pole pair numbers of armature reaction and permanent magnet (PM) excitation on rotor are equal. Furtherly, the inner and outer stators with different split ratios and same split tooth number are employed to increase torque production because armature windings with high winding factor and high turn number can be used. In addition, the employment of hybrid magnet excitation can increase space utilization and enhance the air gap flux density with low harmonic distortion. Therefore, the proposed DSR-HMDSFMM can achieve high torque production with the same volume and PM usage. In order to find the optimal split ratio match of stators, several DSR-HMDSFMMs with different combinations of split ratios are proposed and calculated. The configuration and operating principle are illustrated, together with electromagnetic performances of the proposed machines analyzed using finite element analysis (FEA). The FEA-predicted results show that the proposed HMDSFMM exhibits high air-gap flux density with low harmonic distortion and high torque density, which is promising for the direct-drive applications. [ABSTRACT FROM AUTHOR]

Critical velocity is very important for smoke control in longitudinally ventilated subway tunnel fires. Numerical investigations are conducted in this paper to study the impacts of metro train blockages on critical velocity in sloping subway tunnel fires by using fire dynamics simulator (FDS) tunnel models validated with the field-experiment data. Moreover, a global model of critical velocity is presented for the blocked zone of a metro train in subway tunnel fires including influencing factors of the blockage ratio and tunnel slope. The results show that the reduction ratio of critical velocity in the blocked zone is less than the metro-train blockage ratio. The correction factor between the critical velocity reduction ratio and metro-train blockage ratio is 0.545. The aerodynamic shadow zone downstream of a subway train blockage has important impacts on the critical velocity. The critical velocity in the unblocked zone of a metro train is higher than that in the blocked zone of a metro train blockage. The reason is that smoke flow is hindered by the metro train blockage in subway tunnel fires. With an increase in the blockage–fire source distance, the critical velocity first decreases and then tends to be constant. The global model presented can accurately predict the critical velocity in a sloping subway tunnel with a train blockage. The results may provide beneficial suggestions for designing ventilation systems for subway tunnels. [ABSTRACT FROM AUTHOR]

• An improved variational mode decomposition strategy based on particle swarm optimization is proposed to enhance the signal-to-noise ratio. A fitness function based on permutation entropy and mutual information is developed to determine the optimized parameters in variational mode decomposition. • For the different excitation locations, the amplitude of the Rayleigh wave generated by laser irradiation on the defect is larger than on the small area around the defect, and the defect can be effectively detected using B-scans at elevated temperatures according to the abnormal evolution of Rayleigh waves. • For the same excitation locations, the amplitude of R waves gradually decreases at 100–300 °C and is consistent with the simulation, while it is opposite at 400–500 °C. Online monitoring is a critical issue for additive manufacturing components layer by layer to ensure the integrity of the structure. However, the rough surface and high temperature make it difficult to use conventional non-destructive testing methods to carry out. In this work, the laser ultrasonic technique, as a non-contact nondestructive testing method, is applied to detect defects in a 316L stainless steel specimen manufactured using selective laser melting at elevated temperatures. The unreported phenomenon of phase evolution of Rayleigh waves for different excitation locations and temperatures is observed and systematically explored using the finite element method and experiments. Furthermore, an improved variational mode decomposition strategy based on particle swarm optimization is proposed to enhance the signal-to-noise ratio. A fitness function based on permutation entropy and mutual information is developed to determine the optimized parameters in variational mode decomposition. The experimental results indicate that, for the different excitation locations, the amplitude of the Rayleigh wave generated by laser irradiation on the defect is larger than on the small area around the defect, and the defect can be effectively detected using B-scans at elevated temperatures according to the abnormal evolution of Rayleigh waves; for the fixed excitation locations, the amplitude and velocity of Rayleigh waves gradually decreases at 100–500 °C, which will provide a scientific basis for online monitoring and evaluation of additive manufacturing components. [ABSTRACT FROM AUTHOR]

Sweet potato (Ipomoea batatas L.) is the fifth largest food crop in the world, and roasted sweet potato is particularly popular among people worldwide. The aim of this study was to investigate the composition and flavor variations of four roasted sweet potatoes with different flesh colors (white, yellow, red and purple) and their relationship with sensory descriptors. Results showed that the starch content of all varieties of sweet potatoes decreased after baking, while the maltose content was significantly increased (p < 0.05) in all of them after roasting. Aroma volatiles were then analysed by headspace solid-phase microextraction/comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (HS-SPME / GC × GC-TOF MS), and a total of 120 compounds were identified, with aldehydes having the highest percentage of content in all samples (37%-53.16%). Multivariate statistical analysis of these compounds yielded 63 key difference compounds (VIP > 1, p < 0.05). Combined with gas chromatography-olfactory mass spectrometry (GC-O-MS) technique, 18 main aroma compounds including maltol, β-damascenone and phenylacetaldehyde were identified. Finally, the samples were subjected to sensory evaluation and analysed in combination with the GC-O-MS results. The results showed that the compounds guaiacol, 1-octen-3-ol, maltol, acetic acid, octanal and β-damascenone were positively correlated with burnt, earthy, caramel, sour, green and floral aromas, respectively. These findings may be the main reason for the different aromas of different coloured roasted sweet potatoes and provide new insights into the molecular-level differences in sensory properties of different coloured roasted sweet potatoes. [Display omitted] • GC×GC–TOF MS was used to detect volatile compounds in roasted sweet potato. • The key volatile aromatic compounds were identified in different species of roasted sweet potato. • The main factor affecting the flavor of roasted sweet potato is the maltose content. • After roasting, Yanshu No. 25 was the variety with the highest caramel flavor score. [ABSTRACT FROM AUTHOR]

This paper addresses the predefined-time distributed optimization of nonlinear multi-agent system using a hierarchical control approach. Considering unknown nonlinear functions and external disturbances, we propose a two-layer hierarchical control framework. At the first layer, a predefined-time distributed estimator is employed to produce optimal consensus trajectories. At the second layer, a neural-network-based predefined-time disturbance observer is introduced to estimate the disturbance, with neural networks used to approximate the unknown nonlinear functions. A neural-network-based anti-disturbance sliding mode control mechanism is presented to ensure that the system trajectories can track the optimal trajectories within a predefined time. The feasibility of this hierarchical control framework is verified by utilizing the Lyapunov method. Numerical simulations are conducted separately using models of robotic arms and mobile robots to validate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

In order to address the issues of unfairness in consensus and subjectivity bias in data, while further expanding the traditional minimum cost consensus model (MCCM) in terms of opinion dimension and consensus round, we propose the multi-dimensional MCCM (MD-MCCM) and multi-round MCCM (MR-MCCM). Subsequently, we introduce the concepts and definitions pertaining to these two variants of consensus and formulate their respective consensus model frameworks. To benefit from the advantages of both, we integrate these two types of consensus models, thereby introducing the concept of multi-dimensional multi-round minimum cost consensus. To address the issues of unfairness and subjectivity in the consensus-reaching process, we propose two specific reward and punishment measures and devise the multi-dimensional multi-round consensus iterative mechanisms. These mechanisms facilitate an iterative update of decision-makers' opinions, weights, and unit costs within the feedback process. Based on this foundation, we construct the multi-dimensional multi-round MCCM (MDMR-MCCM) involving Euclidean and Manhattan distance measures, and their corresponding algorithm and consensus reaching process are presented. Finally, a group decision problem concerning site selection validates the rationality and effectiveness of our models. Moreover, a comparative analysis of results obtained using different models is provided. • Multi-dimensional multi-round minimum-cost consensus models are proposed. • Consensus iterative mechanism involving reward and punishment measures is integrated with the models. • Different distance measures are used to assess the distance between decision-makers in the consensus reaching process. • The models ensure the fairness of DMs and avoid the bias of subjectivity in data specification. • A site selection case study is performed to verify the rationality and effectiveness of presented methodology. [ABSTRACT FROM AUTHOR]

In this paper, a direct immersion solid‐phase microextraction procedure for the simultaneous analyses of four primary riot control agents: 2‐chloroacetophenone, o‐chlorobenzylidene malonitrile, dibenz(b,f)‐1,4‐oxazepine, and oleoresin capsicum at μg/L concentration from environmental water was developed. Several parameters that influence the extraction effectiveness were investigated, including fiber type, extraction temperature, extraction time, starring rate, and salinity. Under the recommended conditions, the optimized method had reasonable linearity and accuracy. The average recovery of this method ranged from 84 to 108.1%. The limit of detection for all the analytes ranged from 0.2 to 3 μg/L and the limit of quantification ranged from 1 to 10 μg/L, respectively. A relative standard deviation from 3.0 to 4.3% can be achieved depending on the compounds. The procedure was applied to analyze all the four riot control agents simultaneously in several environmental samples. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to study the well-posedness problem for weak solutions of Navier–Stokes equations in gas dynamics. We consider rough initial data, in B V ∩ L 1 . The well-posedness theory of Liu and Yu (Commun Pure Appl Math 75(2):223–348, 2022) for the isentropic Navier–Stokes equations is extended to the Navier–Stokes equations with an additional equation for the conservation of energy. A key step is to treat the energy equation as mainly for the dissipation of the temperature. The dissipation is analyzed through the heat kernel with BV variable coefficient constructed in Liu and Yu (2022). This step is natural from the physical point of view, but estimates for the temperature are required to be sufficiently robust for the validity of the conservation of energy in the weak sense; for this, we establish the regularity of the solutions, particularly the estimates of their time derivatives through refined estimates of the heat kernel. [ABSTRACT FROM AUTHOR]

Intensive stage multicluster fracturing is the main technology of deep shale gas development, but this technology is easy to lead to the uneven propagation of multiple fractures. In order to deeply analyze the influence mechanism and law of proppant flow in the wellbore on multiple fractures and propagation, Firstly, based on the theoretical knowledge of computational fluid dynamics (CFD), a numerical model of solid-liquid two-phase flow of proppant migration in horizontal wellbore is established, which is calculated and solved by using the Euler-Euler multiphase-flow mixture model, and the effects of different influencing factors on the migration and distribution of proppant in wellbore are studied. Then, based on the fluid structure coupling theory, a planar three-dimensional (PL3D) numerical model of multicluster fracturing in horizontal wells is established. Taking the numerical simulation results of wellbore proppant migration as the initial condition, the influence law of proppant settlement on the fluid volume distribution among multiple clusters and the difference of multifracture geometry is clarified. The results show that the proppant content in the horizontal wellbore increases from heel end to toe end. The fracturing fluid viscosity and sand ratio are the main influencing parameters. The proppant settlement in the wellbore is also an important factor affecting the liquid and sand injection of multifracture. When considering the proppant settlement in the wellbore, the phenomenon of multifracture uneven propagation is more significant. The construction scheme of medium viscosity, large displacement fracturing fluid, large proppant size, and medium sand ratio in a certain range is conducive to promote the even propagation of multifracture. This study is helpful to guide the construction design of multicluster fracturing in horizontal wells, so as to improve the success rate of multicluster fracturing and greatly save the construction cost. [ABSTRACT FROM AUTHOR]

Two (5-(thiophene-2-yl)oxazole derived chemosensors, N′-(2-hydroxybenzylidene)-5-(thiophene-2-yl)oxazol-4-carbonylhydrazine (L1) and N′-(3-ethoxy-2-hydroxybenzylidene)-5-(thiophene-2-yl)oxazol-4-carbonylhydrazine (L2), were designed and synthesized via a fluorescence turn-on strategy to specifically recognize Ga3+. Both L1 and L2 showed highly sensitive and selective fluorescence responses toward Ga3+ in the DMSO/H2O buffer solution and exhibited more effective anti-interference performance over other coexisting metal ions including Al3+ and In3+. The limits of detection for Ga3+ were found to be 6.23 × 10−8 M and 1.15 × 10−8 M with L1 and L2, respectively. Job's plots and mass spectrometry (ESI-MS) suggested a 1 : 2 complexation ratio of sensors to Ga3+ with binding constants of 8.54 × 108 M2 for L1 and 1.06 × 108 M2 for L2. The proposed interaction mechanism was further supported by density functional theory. In addition, both sensors were applied to the detection of Ga3+ in environmental water samples. [ABSTRACT FROM AUTHOR]

Two large earthquakes, the Maduo MS 7.4 earthquake and the Menyuan MS 6.9 earthquake, have been successfully recorded on the Chinese mainland, since the data of the CSES satellite were put into service for earthquake prediction work on the Chinese mainland at the end of April 2020. Obvious variations in O+ density and electron density were found during our weekly data processing work during 5–11 May 2021 and 28 December 2021–2 January 2022, respectively. Two warnings of impending events around the anomalous areas within two weeks had been reported immediately after the anomaly appearance. The Maduo MS 7.4 earthquake occurred on 22 May 2021 and the Menyuan MS 6.9 earthquake on 8 January 2022, during these two warning periods. More details were revealed after these two large shocks occurred. Ionospheric enhancement took place on 8 May 2021, with a magnitude of 41.6% for O+ density and 22.2% for electron density, a distance of 680 km from the Maduo epicenter, 14 days prior to the event. Before the Menyuan earthquake, ionospheric enhancement took place on 28 December 2021, as well as during its revisiting orbit on 2 January 2022, with a magnitude of 47.3% for O+ density and 38.4% for electron density, an epicentral distance of 120 km, 11 and 6 days prior to this event. The Kp index was also examined to avoid the influence from solar activities. Despite this, accurate earthquake prediction is not possible due to much uncertainty, such as the correct location and magnitude of an impending event. Thus, long-term practice and comprehensive investigation of the seismo-ionospheric influence are necessary in the future. [ABSTRACT FROM AUTHOR]

Nondestructive testing and evaluation technology of the total focusing method (TFM) based on full matrix capture (FMC) is a hot spot in the current array of ultrasonic testing technology. In this work, a TFM approach of ultrasonic phased array based on compressed sensing (CS-TFM) is proposed, aiming to solve the storage and transfer of a significant amount of FMC data. It is well known that TFM is derived from huge amounts of FMC data. First, the FMC signals obtained from the test are studied. The effects of the sparse basis and the reconstruction algorithm on the FMC data reconstruction accuracy are analyzed. Then, TFM is carried out based on the FMC data obtained by compressive reconstruction. The mesh partition method that affects the accuracy and speed of CS-TFM is investigated. The result demonstrates that excellent recoveries can be obtained using measurement points less than the Nyquist sampling limitation required. The CS-TFM method can reconstruct at a compression ratio (CR) of 60%, the error of reconstructed FMC data is about 3%, which can be used for TFM of defects. Moreover, The proposed optimal mesh partition method can reduce the TFM time while ensuring imaging accuracy. CS-TFM is expected to provide a new idea for reducing the complexity and hardware requirements of the detection system. [ABSTRACT FROM AUTHOR]

The vibration compensation control of a hovering helicopter rescue simulator mounted on a crane beam is studied in this research. A Stewart platform is used as the motion generator of the helicopter simulation cabin and the vibration compensation device of the beam, simultaneously. This study describes how the dynamic model of the Stewart platform with consideration of the beam vibration is established. To determine the interference of the Stewart platform motion control in the special application of a large component flexible base requiring large-scale movement, a hybrid vibration controller composed of a feed-forward compensation module and a PD (proportional-derivative) feedback control module is designed. The experimental results show that this method can effectively compensate for the beam vibration and improve the accuracy of the motion reproduction of a helicopter simulation cabin. [ABSTRACT FROM AUTHOR]

In the process of extracting the characteristic frequency of the fault signal of the rolling bearing in the mechanical system, the signal transmission paths between the fault points inside the bearing and the sensor are diversified, which will produce compound faults of different forms and combinations. These composite faults will lead to a series of serious consequences such as distortion and aliasing of the fault characteristic spectrum. In order to solve these problems, this paper proposes a composite fault feature separation method for rolling bearing based on the mixed function decoupling model. Firstly, the functional series model of the fault system is established, and some kernel functions of functional series are obtained. Secondly, the coupling frequency relationship is established and the recursive search algorithm of frequency energy is applied to decouple the compound fault coupling frequency into a single fault frequency feature set. Finally, the threshold method of fault characteristic frequency energy entropy is utilized to optimize the single fault frequency feature set and identify the true and false features, so as to identify each characteristic frequency point of the composite fault. Experimental results show that, under the condition of low SNR, the proposed method can decouple no more than three typical composite fault signals without depending on the signal filter. [ABSTRACT FROM AUTHOR]

An inverse wave modeling-based method is proposed for globally reconstructing the sound field in room environments. The method builds the wave model of the sound field as prior knowledge to support the reconstruction under strong reverberation. In this method, the whole space is divided into a set of subdomains. Based on the theory of discretization-based numerical simulation, a wave model that can describe the transfer characteristic between any subdomain and the source is built. Supported by this model, the sound source is recovered based on spatial sound pressure sampling and the global sound field reconstruction can be further accomplished in the reverberant environment. In particular, the shape function with the property of sparsity is constructed in building the wave model. Then, the intensity on the point source is represented by a sparse vector over the subdomains, and then, the sparse method can be used to achieve the recovery of this vector, which reduces the sampling burden in the space. Numerical verifications are performed to evaluate the performances of the proposed method. It demonstrates that the proposed method is capable of obtaining accurate reconstructions in a strong reverberant environment. It also shows that the method is applicable to problems with complicated excitations in the low-frequency range. [ABSTRACT FROM AUTHOR]

Subsurface drip irrigation systems with water and fertilizer-aerated irrigation technology have helped improve crop yield and quality and are receiving increasing attention in the field of agricultural efficient irrigation. Venturi is an important part of water and fertilizer-aerated irrigation technology as a subsurface drip aeration device, but its performance is yet unknown. Consequently, to explore the working performance of the Venturi applicator as a subsurface drip aeration device, three different structures of DN20 Venturi applicators were selected, and the suction characteristics, working parameters, and stability of the Venturi aerators at five inlet pressure levels were measured according to a certain outlet pressure gradient. The results indicated that the gas injection flow of different Venturi aerators fluctuate in the form of peak–valley quasi periodic motion, and the fluctuation range is 20–300 L/h ; under different inlet pressure levels, the average gas injection flows of the three Venturi aerators increase with the pressure difference, and the maximum average gas injection flow of the type plasson (PL) and type netafim (NF) types remains generally stable with the increase in inlet pressure. Furthermore, the standard deviation of gas injection flow is consistent with the gas injection flow. Under the same working condition, the type mazzei (MZ)-type Venturi device has the advantages of low working pressure range, large working flow, and high stability compared with PL and NF types, and thus it is suitable for use as the gas-filling equipment of subsurface drip irrigation systems. Furthermore, a suction estimation model related to the working inlet and outlet pressure is constructed, and the suction capacity can be estimated according to the inlet and outlet pressures of the Venturi aerator. The study findings can provide a reference for engineering application selection and help to improve the performance of Venturi. [ABSTRACT FROM AUTHOR]

Non-equilibrium phase transition will take place in the pressure oscillation tube if the intake of wave rotor refrigerator (WRR) contains condensable components, which will affect intensity and speed of the wave system in the tube, and further affect the port matching of WRR. In this paper, numerical model of non-equilibrium phase transition is established and the effects on intensity of the wave system and the port matching is studied. The properties of polar gas are described by the cubic-plus-association (CPA) gas state equation, improving the accuracy of computational fluid dynamics (CFD) calculations. By using the model, the design precision of two-phase WRR is improved. Besides, the results of numerical simulation are verified by experiments. [ABSTRACT FROM AUTHOR]

Text classification is a popular research topic in the natural language processing. Recently solving text classification problems with graph neural network (GNN) has received increasing attention. However, current graph-based studies ignore the hidden information in text syntax and sequence structure, and it is difficult to use the model directly for processing new documents because the text graph is built based on the whole corpus including the test set. To address the above problems, we propose a text classification model based on long short-term memory network (LSTM) and graph attention network (GAT). The model builds a separate graph based on the syntactic structure of each document, generates word embeddings with contextual information using LSTM, then learns the inductive representation of words by GAT, and finally fuses all the nodes in the graph together into the document embedding. Experimental results on four datasets show that our model outperforms existing text classification methods with faster convergence and less memory consumption than other graph-based methods. In addition, our model shows a more notable improvement when using less training data. Our model proves the importance of text syntax and sequence information for classification results. [ABSTRACT FROM AUTHOR]

Design requirements of the structural features, the material properties, and the processing capabilities are hard to be satisfied in nanotechnologies simultaneously. In this paper, TiO2 nanoparticles that are chemically reliable have been processed through the doctor blade method to realize a kind of field enhancement nanostructure, aiming to enhance the dielectric-barrier-discharge plasma actuation performance. It is found that the thrust enhancement rate could be approximately 72% at 13 kV and 8 kHz, compared to the controlled samples. In addition, a threshold phenomenon of the thrust enhancement effect was also found from the experiments, where the applied voltage and frequency lower than specific criteria could both lead to a decrease in the thrust generation and vice versa. It is suggested that the increase in the ionization frequency resulted from the field enhancement effect of the nanostructures is the leading mechanism for the extra thrust generation, which is inconsistent with the experimental examinations of the plasma characteristics and the plasma kinetic simulation. The results suggested that TiO2 nanoparticles could be used to improve the actuation performance in harsh environments with sound substrate compatibility. [ABSTRACT FROM AUTHOR]

Although great progress has been made in generic object detection by advanced deep learning techniques, detecting small objects from images is still a difficult and challenging problem in the field of computer vision due to the limited size, less appearance, and geometry cues, and the lack of large-scale datasets of small targets. Improving the performance of small object detection has a wider significance in many real-world applications, such as self-driving cars, unmanned aerial vehicles, and robotics. In this article, the first-ever survey of recent studies in deep learning-based small object detection is presented. Our review begins with a brief introduction of the four pillars for small object detection, including multiscale representation, contextual information, super-resolution, and region-proposal. Then, the collection of state-of-the-art datasets for small object detection is listed. The performance of different methods on these datasets is reported later. Moreover, the state-of-the-art small object detection networks are investigated along with a special focus on the differences and modifications to improve the detection performance comparing to generic object detection architectures. Finally, several promising directions and tasks for future work in small object detection are provided. Researchers can track up-to-date studies on this webpage available at: https://github.com/tjtum-chenlab/SmallObjectDetectionList. [ABSTRACT FROM AUTHOR]

Excessive chemical fertilizer use leads to soil nitrogen leaching. Biogas slurry, which is rich in nitrogen, has been proposed as an organic substitute for chemical fertilizer via drip irrigation. However, the dynamics of nitrogen migration and potential threats to biogas slurry return remain unclear. Using a two-year field experiment and HYDRUS software, this study modeled soil moisture and nitrogen migration under biogas slurry drip irrigation. The validated model accurately simulates water and nitrogen migration, predicting nitrogen leaching dynamics. Compared to chemical fertilizer treatment, differences in soil hydraulic parameters under biogas slurry drip irrigation impact moisture and nitrate nitrogen distribution. Increasing biogas slurry proportion enhances nitrate nitrogen content in the root layer, promoting plant nitrogen absorption while reducing leaching by 49.66%. Optimizing the irrigation system involves high concentration substitution in early growth and low concentration in late growth, mitigating nitrogen leaching, and enhancing plant root absorption. [Display omitted] • HYDRUS simulates water/fertilizer migration under biogas drip irrigation. • Law of biogas slurry topdressing water and fertilizer migration. • Biogas slurry topdressing reduces nitrate leaching, increases nitrogen uptake. • Optimization strategy for biogas slurry topdressing under drip irrigation proposed. [ABSTRACT FROM AUTHOR]

This paper is focused on the application of the machine learning for predicting structural response of ring stiffened cylindrical shells subjected to far-field underwater explosion. Three deep neural network (DNN) models are combined to predict the progressive plastic deformation behaviour of stiffened cylindrical shells subjected to the shock wave produced by a TNT charge. In the DNN regression models, the input variables include the charge mass, stand-off distance, detonation depth, cylindrical shell thickness, stiffener web and flange. These three DNN models composed of multi hidden layers are trained based on the data collection originated from a series of simulations performed by the ABAQUS finite element solver. Grid search is introduced to the hyperparameter tuning for deep learning, improving the prediction performance of machine learning methods. The DNN models are compared to the models trained using another three methods: multiple linear regression, decision tree and k-nearest neighbour. An improved Adam optimisation algorithm is used to increase the accuracy of prediction. The challenges encountered during the predictions are discussed to provide a more comprehensive insight into the advantage of the proposed DNN models. The DNN regression models can well predict the permanent plastic deformation and strain of stiffened cylindrical shells. • Improved deep neural network is applied to predict the impact response of stiffened cylindrical shells. • Various regression algorithms in machine learning are compared. • Grid search method is used for the hyperparameter optimisation. • It is achieved the rapid and accurate assessment of plastic deformation and strain. [ABSTRACT FROM AUTHOR]

Biogas slurry (BS), waste water of energy production, holds potential as both an irrigation water resource and a liquid fertilizer source. Typically combined with water and mineral fertilizer at specific ratios, BS is applied in fields with drip irrigation systems to enhance crop growth. However, the soil water infiltration process with BS drip irrigation remains poorly understood, mainly owing to the BS's differing characteristics from conventional water sources. This study investigated the morphological characteristics, transport and distribution of water in three ratios of BS-water using a soil column experiment, with the post-irrigation surface soil pores and elements analyzed using electron microscopy and energy spectrum scanning techniques. The findings reveal that BS drip irrigation significantly alters the water morphological characteristics, transport process and distribution compared to conventional water sources. The morphology of the wetting-front changed from nearly "hemispherical" to a "half-pear" shape with time in BS drip irrigation. The soil-wetting front's vertical distance was notably smaller, approximately 50% of the vertical depth seen with traditional water source drip irrigation, even after redistribution of soil moisture, it was still difficult to reach the depth of the main root zone of most crops. Moreover, The carbon content on the soil surface was increased, ranging between 19.05–47.62% in the BS irrigation scenario, which led to soil pore blockage and a decrease in porosity ranging between 11.99–40.5%. The dynamic viscosity of BS is approximately 50% higher than that of CF.Theses indicate that the combined effect of soil porosity and dynamic viscosity affects the BS infiltration.In conclusion, this paper proposes a BS drip irrigation model with integrated agronomic measures to mitigate the potential adverse effects of BS drip irrigation caused by changes in soil water transportation and distribution. • Soil water infiltration mechanisms was revealed in biogas slurry drip irrigation(BSDI). • Analyzed the limitation of BSDI for return to the fields. • Proposed measures to solve limitations of BSDI. [ABSTRACT FROM AUTHOR]

• The freeze–thaw damage on mechanical performance of asphalt mixture were evaluated. • The cracking progress of asphalt mixture was evaluated with DIC measurement. • The freeze–thaw damage to mesoscopic components of asphalt mixtures was analyzed. • The 3D heterogenous FE models were reconstructed with X-ray scanning test. • The damage mechanisms of asphalt mixtures under freeze–thaw were analyzed. Understanding the fracture characterization of asphalt mixtures is important to improve pavement performance in seasonal frozen regions. It is necessary to analyze the cracking characteristics and mechanism of asphalt mixtures under the action of freeze–thaw damage. The semi-circular bending (SCB) crack test combined with digital image correlation (DIC) was conducted to evaluate the fracture characterization of asphalt mixtures under freeze–thaw cycles. The X-ray scanning measurement, bending beam rheology (BBR) test, oblique shear test, the generalized Maxwell model (GM), and the cohesive zone model (CZM) were utilized to reconstruct the 3D heterogeneous finite element (FE) model and reveal the damage mechanism. The results indicated that the freeze–thaw cycles negatively affected the cracking resistance of asphalt mixtures. After 20 freeze–thaw cycles, the fracture energy, stiffness, flexibility index, stress intensity factor, and crack evolution rate decreased by 22.96%, 19.53%, 63.93%, 63.93%, and 61.15%, respectively. The FE model was able to reflect the mechanical properties of asphalt mixtures with different numbers of freeze–thaw cycles well. The FE model can well reflect the mechanical properties of asphalt mixtures under different numbers of freeze–thaw cycles. It also reveals the deterioration of asphalt mortar properties and interfacial adhesion under the action of freeze–thaw damage, which leads to the reduction of internal stress transfer efficiency and attenuation of cracking resistance of asphalt mixtures. This study contributed to the damage mechanism evaluation of asphalt mixtures in seasonal frozen regions and may help with pavement design, construction, and maintenance. [ABSTRACT FROM AUTHOR]

• Hydrus model can be applied to biogas slurry drip irrigation (BSDI). • Established equation between soil wetting parameters and cumulative infiltration. • Proposed the design method and control strategies for BSDI system. • Determined the factors affecting infiltration for BSDI. As an unconventional water resource, biogas slurry offers a unique opportunity for efficient utilization of both its water and nutrient contents in drip irrigation systems. However, compared with traditional water source drip irrigation (TWSDI), biogas slurry drip irrigation (BSDI) can alter the movement and distribution of water in the soil, which affects root uptake. Therefore, the relevant parameters of the TWSDI system must be modified based on the characteristics of BSDI infiltration. In this study, a model describing the water transport characteristics of biogas drip irrigation was developed based on the HYDRUS model. The relative error between the measured and simulated results was less than 10 %, thus demonstrating that the HYDRUS model can be used for the BSDI. Based on the different initial soil moisture contents, emitter spacings, and emitter discharges, 18 scenarios were simulated using the HYDRUS model. The results revealed that the intersection wetting depth, vertical infiltration and horizontal wetting distances, and wetting uniformity followed the logarithmic, power, and exponential trends, respectively, against the cumulative infiltration quantity. An optimum combination of system layout parameters was proposed considering the wetting uniformity, amount of biogas slurry dissipation, and cost. In addition, the decreasing order of the weight of factors affecting the susceptibility of biogas slurry infiltration was emitter spacing > initial soil moisture content > emitter discharge, providing an adjustment strategy for improving wet uniformity in common BSDI situations. This study provides a novel optimum strategy for designing biogas slurry drip irrigation systems using the HYDRUS model. [ABSTRACT FROM AUTHOR]

Ventilated roofs can improve thermal performance and reduce the energy consumption of building roofs. In this study, the optimal design parameters and adaptability of naturally ventilated roofs were determined through numerical investigations of the effects of different influencing factors on their thermal performance. A three-field coupling numerical simulation method considering temperature, flow, and solar radiation fields was used to improve simulation accuracy. The research results show that the optimal air gap layer thickness of a naturally ventilated roof increases with increasing roof length, which has not been considered in previous studies. The peak interior surface temperature of the ventilated roof increases with increasing outdoor atmospheric pressure. Ventilated roofs with a 30°–40° slope have a stronger stack effect and can better discharge solar heat gains when compared to roofs with other slopes. Interior surface temperature is reduced when phase change materials is set in the upper rather than the lower roof during summer. Phase change materials should be set in the upper roof to save energy. Small damage holes in the upper roof don't apparently affect the ventilated roof thermal performance. The findings of this study can guide optimization design and help evaluate the energy-saving effects of naturally ventilated roofs. • A three-field coupling simulation method is proposed to improve simulation accuracy. • Effect of roof length on thermal performance of ventilated roof is investigated. • Effect of atmospheric pressure on thermal performance of ventilated roof is studied. • Effects of CPCM and damage hole on thermal performance of ventilated roof are studied. • Optimum design parameters of naturally ventilated roofs are presented. [ABSTRACT FROM AUTHOR]

The methods of scanning electron microscopy, energy dispersive analysis and x-ray diffractometry are used to study the kinetics and the mechanism of formation of complex-composition oxide scale on the surface of heat-resistant steel 25Cr18Ni9Si2 during oxidation at 900°C for 500 h. The composition of the scale and the proportion of the gain in the weight to the duration of the oxidation are determined. It is shown that the formation of the composite scale is connected with simultaneous oxidation and reduction of Si, Cr, Fe, and Ni accompanied by refinement of the oxide grains. It is inferred that the dense composite oxide scale is responsible for the high resistance of the steel to oxidation. [ABSTRACT FROM AUTHOR]

Researches in the plasma actuation are increasingly scrutinizing the methodology to enhance the thrust density for the application in the aerodynamic flow control. In this paper, a new method has been proposed and experimentally evaluated. This method is based on the deposition of nanoscaled structures on the electrode surface and the tuning of the applied voltages and frequency. It is found that the thrust enhancement rate resulted from the incorporation of the nanostructures could be approximately 78%, relative to the controlled group, under 14 kV and 7 kHz. However, a threshold effect has been founded across all of the tested samples, where lower applied voltage and frequency could lead to the decrease in the thrust generation. Capacitor charging effects are basically not sensitive to the introduction of the nanostructures in electrical characteristic. Other experimental features and electric field simulation results also indicate the effectiveness of introducing nanoscaled structures into DBD plasma actuators, thus providing a new way to improve mechanical performance. [ABSTRACT FROM AUTHOR]

Electrodeposition provides a simple but effective way to prepare advanced electrode for the application in electrochemical field. In this work, NiMoSe ternary nanospheres were deposited on nickel foam (NiMoSe/NF) by one-step electrodeposition. The morphology, phase and chemical composition of the electrode was characterized by using SEM, TEM, XRD and XPS. The electrode exhibited excellent performance for both urea oxidation reaction (UOR) and hydrogen evolution reaction (HER). It only required 1.39 V and 81 mV (vs. RHE) to deliver a current density of 10 mA/cm2 for UOR and HER, respectively. The electrolyzer constructed with NiMoSe/NF as both anode and cathode could deliver a current density of 10 mA/cm2 at a driving potential of 1.44 V. The stability test showed that the electrode had good durability as electrode for both UOR and HER. Considering the easiness, simplicity and low cost, the NiMoSe/NF electrode could find wide application in urea electrolysis. [Display omitted] • Ternary NiMoSe/NF electrocatalyst prepared by simple electrodeposition method. • NiMoSe/NF exhibits excellent electrocatalytic activity for both UOR and HER. • NiMoSe/NF electrode demonstrates good stability for urea electrolysis. • The electrochemical conversion process provides potentiality for HER via treatment of urea-rich wastewater [ABSTRACT FROM AUTHOR]

Multi-scale vehicle detection is an important application in the field of object detection, and Feature Pyramid Network (FPN) is an important means to deal with multi-scale object detection tasks. However, baseline method is the common method used in most of the existing network structure, which represents the input image information by selecting one from the output layer of FPN, and discard other layers. This not only limits the performance of the network structure, but also performs poorly when dealing with the problem of excessive scale differences. To solve this problem, a novelty candidate region aggregation network (CRAN) is proposed in this paper. The candidate regions of different feature layers are effectively aggregated to improve the network generalization performance. Specifically, calculate the similarity between different feature layers through a feature quality score module, and use this as a quantity factor to determine the number of candidate regions reserved for the corresponding feature layer. Finally, they are aggregated into a more comprehensive candidate region group. Further, in order to improve the detection efficiency of small objects, an area cross entropy loss function is proposed. It makes the model pay more attention to small targets by adding a monotonic decrease based on the area. Finally, the proposed CRAN and the area cross entropy loss function are applied to the advanced detectors. The experimental results in the KITTI and UA-DETRAC datasets show that this method has good performance on vehicle objects in different scenarios, and can meet the requirements of practical application. [ABSTRACT FROM AUTHOR]

The lncRNA SNHG6 (small nucleolar RNA host gene 6) plays vital roles in tumorigenesis and the progression of hepatocellular carcinoma (HCC). However, the regulatory mechanisms of SNHG6 are largely unknown. In this study, we identified, via quantitative proteomics, specific cytoskeleton-associated proteins and enzyme modulators to be potential targets of SNHG6. SNHG6 reduced the mRNA levels of lysine methyltransferase, SET domain containing 7 (SETD7) and leucine zipper transcription factor-like 1 (LZTFL1) by posttranscriptional destabilization. Silencing of SETD7 or LZTFL1 reversed the suppressive effects of SNHG6 knockdown on HCC progression. Heterogeneous nuclear ribonucleoprotein L (HNRNPL) and polypyrimidine tract binding protein 1 (PTBP1) were identified as SNHG6-interacting proteins that bind to SETD7 or LZTFL1 mRNA. Forced expression of SNHG6 led to HNRNPL being competitively adsorbed by SNHG6, thereby removing its stabilizing effect on SETD7. Concurrently, the functional SNHG6-PTBP1 complex facilitated the degradation of LZTFL1 mRNA in hepatoma cells. These results indicated that SNHG6 promotes HCC progression by functioning as a "decoy plus guide" for HNRNPL and PTBP1 to facilitate mRNA decay of SETD7 and LZTFL1 , thereby serving as a novel therapeutic target for HCC. • SNHG6 reduces SETD7 and LZTFL1 mRNA levels by post-transcriptional destabilization. • SNHG6-interacting proteins include RNA-binding proteins HNRNPL and PTBP1. • HNRNPL is competitively adsorbed by SNHG6, destabilizing SETD7 mRNA. • The functional SNHG6-PTBP1 complex facilitates the degradation of LZTFL1 mRNA. • SNHG6 promotes HCC progression by functioning as a "decoy plus guide". [ABSTRACT FROM AUTHOR]

It's highly desired but challenging to synthesize self-supporting nanohybrid made of conductive nanoparticles with metal organic framework (MOF) materials for the application in the electrochemical field. In this work, we report the preparation of Ni2P embedded Ni-MOF nanosheets supported on nickel foam through partial phosphidation (Ni2P@Ni-MOF/NF). The self-supporting Ni2P@Ni-MOF/NF was directly tested as electrode for urea electrolysis. When served as anode for urea oxidation reaction (UOR), it only demands 1.41 V (vs RHE) to deliver a current of 100 mA cm−2. And the overpotential of Ni2P@Ni-MOF/NF to reach 10 mA cm−2 for hydrogen evolution reaction HER was only 66 mV, remarkably lower than Ni2P/NF (133 mV). The exceptional electrochemical performance was attributed to the unique structure of Ni2P@Ni-MOF and the well exposed surface of Ni2P. Furthermore, the Ni2P@Ni-MOF/NF demonstrated outstanding longevity for both HER and UOR. The electrolyzer constructed with Ni2P@Ni-MOF/NF as bifunctional electrode can attain a current density of 100 mA cm−2 at a cell voltage as low as 1.65 V. Our work provides new insights for prepare MOF based nanohydrid for electrochemical application. [ABSTRACT FROM AUTHOR]

We consider the problem of computing the diameter of a unicycle graph (i.e., a graph with a unique cycle). We present an O (n) time algorithm for the problem, where n is the number of vertices of the graph. This improves the previous best O (n log ⁡ n) time solution [Oh and Ahn, ISAAC 2016]. Using this algorithm as a subroutine, we solve the problem of adding a shortcut to a tree so that the diameter of the new graph (which is a unicycle graph) is minimized; our algorithm takes O (n 2 log ⁡ n) time and O (n) space. The previous best algorithms solve the problem in O (n 2 log 3 ⁡ n) time and O (n) space [Oh and Ahn, ISAAC 2016], or in O (n 2) time and O (n 2) space [Bilò, ISAAC 2018]. • The paper presents a linear time algorithm for computing the diameter of unicycle graphs. • The paper gives a new algorithm which finds a new edge to add to a tree so that the diameter of the new graph is minimized. • The algorithms rely on certain domination relations among edges of the graphs. [ABSTRACT FROM AUTHOR]

In the last decades, rewetting of drained peatlands is on the rise worldwide, to restore their significant carbon sink function. Despite the increasing understanding of peat microbiomes, little is known about the seasonal dynamics and network interactions of the microbial communities in these ecosystems, especially in rewetted fens (groundwater-fed peatlands). Here, we investigated the seasonal dynamics in both prokaryotic and eukaryotic microbiomes in three common fen types in Northern Germany. The eukaryotic microbiomes, including fungi, protists and microbial metazoa, showed significant changes in their community structures across the seasons in contrast to largely unaffected prokaryotic microbiomes. Furthermore, our results proved that the dynamics in eukaryotic microbiomes in the rewetted sites differed between fen types, specifically in terms of saprotrophs, arbuscular mycorrhiza and grazers of bacteria. The co-occurrence networks also exhibited strong seasonal dynamics that differed between rewetted and drained sites, and the correlations involving protists and prokaryotes were the major contributors to these dynamics. Our study provides the insight that microbial eukaryotes mainly define the seasonal dynamics of microbiomes in rewetted fen peatlands. Accordingly, future research should unravel the importance of eukaryotes for biogeochemical processes, especially the under-characterized protists and metazoa, in these poorly understood ecosystems. [ABSTRACT FROM AUTHOR]

A series of heteroleptic Ir(III) complexes composed of two cyclometalated C^N ligands and one dipyrrinato ligand used as an ancillary ligand are synthesized and characterized. With the introduction of a fluorine atom, phenyl ring or diphenylamino group into both C^N ligands and by keeping the ancillary ligand unchanged, these Ir(III) dipyrrinato phosphors do not show an obvious shift in their emission bands. They exhibit emissions extending well into the near-infrared region with an intense band located at around 685 nm in both photo- and electroluminescence spectra, and the deep red to near-infrared organic light emitting diodes (OLEDs) based on them afforded a maximum external quantum efficiency of 2.8%. Density functional theory (DFT) calculations show that both the electronic contributions on the lowest unoccupied molecular orbitals (LUMOs) and the highest energy semi-occupied molecular orbitals (HSOMOs) are mainly localized on the dipyrrinato ligand, indicating that the ancillary ligand, which remains unchanged in this series, exhibits a lower triplet state energy in the iridium phosphors than those involving the C^N ligands. Therefore a switch from "(C^N)2Ir" to dipyrrinato ligand-based emission is observed in these iridium(III) complexes. [ABSTRACT FROM AUTHOR]

Nowadays, it has become an imminent challenge of developing a robust and efficient oil/organic solvent absorbing/releasing along with oil–water separating material. Herein, a simple and environment-friendly one-step immersion method is developed for fabricating superhydrophobic carbon felts with extraordinary properties. The as-prepared superhydrophobic carbon felts reveal outstanding durability and stability even exposed to various harsh environments, such as acid, base, salt, organic solvent, and UV light for quite long time. The superhydrophobic carbon felts exhibit excellent fire resistance, and the materials can stand at least 5 times of ethanol-soaking and burning without marked influencing on the superhydrophobicity. Meanwhile, the resultant materials reveal outstanding oil adsorption and oil–water separation performance. The superhydrophobic carbon felt can still absorb 7 times its own mass of cooking oil even after 10 extrusion cycles. Moreover, the oil–water separation efficiency can still reach 98.85% after 10 times of separation. Consequently, the materials can be used in oil/organic solvent collection and oil–water separation successfully. Therefore, the simple, environment-friendly, cost-effective fabrication method together with the extraordinary durability and stability, excellent and efficient performance will find its potential applications in industrial production and environmental remediation. A simple and environment-friendly one-step immersion method for fabricating superhydrophobic carbon felts is developed. The as-prepared superhydrophobic carbon felts reveal excellent fire resistance along with extraordinary durability and stability upon various harsh environments. Furthermore, the superhydrophobic carbon felts exhibit outstanding oil/organic solvent adsorption/releasing and oil–water separation performance. [ABSTRACT FROM AUTHOR]

The lncRNA SNHG6 (small nucleolar RNA host gene 6) plays vital roles in tumorigenesis and the progression of hepatocellular carcinoma (HCC). However, the regulatory mechanisms of SNHG6 are largely unknown. In this study, we identified, via quantitative proteomics, specific cytoskeleton-associated proteins and enzyme modulators to be potential targets of SNHG6. SNHG6 reduced the mRNA levels of lysine methyltransferase, SET domain containing 7 (SETD7) and leucine zipper transcription factor-like 1 (LZTFL1) by posttranscriptional destabilization. Silencing of SETD7 or LZTFL1 reversed the suppressive effects of SNHG6 knockdown on HCC progression. Heterogeneous nuclear ribonucleoprotein L (HNRNPL) and polypyrimidine tract binding protein 1 (PTBP1) were identified as SNHG6-interacting proteins that bind to SETD7 or LZTFL1 mRNA. Forced expression of SNHG6 led to HNRNPL being competitively adsorbed by SNHG6, thereby removing its stabilizing effect on SETD7. Concurrently, the functional SNHG6-PTBP1 complex facilitated the degradation of LZTFL1 mRNA in hepatoma cells. These results indicated that SNHG6 promotes HCC progression by functioning as a "decoy plus guide" for HNRNPL and PTBP1 to facilitate mRNA decay of SETD7 and LZTFL1, thereby serving as a novel therapeutic target for HCC. [ABSTRACT FROM AUTHOR]

Hashing-based techniques have provided attractive solutions to cross-modal similarity search when addressing vast quantities of multimedia data. However, existing cross-modal hashing (CMH) methods face two critical limitations: 1) there is no previous work that simultaneously exploits the consistent or modality-specific information of multi-modal data; 2) the discriminative capabilities of pairwise similarity is usually neglected due to the computational cost and storage overhead. Moreover, to tackle the discrete constraints, relaxation-based strategy is typically adopted to relax the discrete problem to the continuous one, which severely suffers from large quantization errors and leads to sub-optimal solutions. To overcome the above limitations, in this article, we present a novel supervised CMH method, namely Asymmetric Supervised Consistent and Specific Hashing (ASCSH). Specifically, we explicitly decompose the mapping matrices into the consistent and modality-specific ones to sufficiently exploit the intrinsic correlation between different modalities. Meanwhile, a novel discrete asymmetric framework is proposed to fully explore the supervised information, in which the pairwise similarity and semantic labels are jointly formulated to guide the hash code learning process. Unlike existing asymmetric methods, the discrete asymmetric structure developed is capable of solving the binary constraint problem discretely and efficiently without any relaxation. To validate the effectiveness of the proposed approach, extensive experiments on three widely used datasets are conducted and encouraging results demonstrate the superiority of ASCSH over other state-of-the-art CMH methods. [ABSTRACT FROM AUTHOR]

Micro-pyramid functional surfaces are currently widely used in various advanced scientific, technological, industrial, and engineering fields with their excellent performances of compactness, light weight and higher heat transfer performance. Many recent studies have introduced micro cutting as a method to achieve high-quality micro pyramid surfaces. This paper concerns a micro-pyramid with a height and slope of 60 μm and 30°. Firstly, numerical simulation of the optical effect related to micro-pyramid surfaces was carried out to reveal the mechanism of functional surface imaging and its typical and potential applications. The simulated optical effect shows that the micro-pyramid can form four virtual images on the same side of an object. Next, a novel and simple fabrication method for micro-pyramidal structures was developed by using cross cutting with a 120° V-tip diamond tool by ultra-precision raster milling (UPRM), which can obtain good surface quality, high form accuracy and efficient productivity in contrast to grinding, laser machining and etching. Finally, precision injection molding was employed to replicate a micro-pyramid on the PMMA for optical testing. Although the quality of molded micro pyramid pattern decreased, optical testing showed that clear images were obtained, and the experimental results were consistent with the simulation results. [ABSTRACT FROM AUTHOR]

This paper aimed to explore the application value of CT imaging in the correlation analysis of communicating hydrocephalus (CH) after decompressive craniectomy (DC) of craniocerebral injury (CI). 410 patients with craniocerebral trauma who were admitted to the hospital from October 2015 to October 2019 were taken as subjects, among which 130 patients suffered from CH. All patients underwent craniocerebral CT examination, and logistic regression was applied to analyze the risk factors of hydrocephalus in CI and hydrocephalus after DC surgery. The results showed that the coma time (OR = 5.1283, P = 0.001), subarachnoid hemorrhage (SAH) (OR = 7.6543, P = 0.020), Glasgow Coma Scale (GCS) score no more than 8 points (OR = 3.5480, P = 0.001), intraventricular hemorrhage (OR = 2.2653, P = 0.003), cerebral contusion and laceration (OR = 1.036, P = 0.002), and subdural hemorrhage (OR = 2.4376, P = 0.001) were independent risk factors for CH. Bilateral DC (OR = 15.342, P = 0.023), second surgery (OR = 7.021, P = 0.004), bone window height (OR = 6.543, P = 0.041), and bone window area (OR = 1.035, P = 0.012) were independent risk factors for CH after DC surgery. It suggested that CT imaging technology could be utilized in the diagnosis of CI. The risk factors of CH included coma time, SAH, GCS score no more than 8, intraventricular hemorrhage, brain contusion, subdural hematoma, bilateral DC, bone window height, bone window area, and second surgery. [ABSTRACT FROM AUTHOR]

Radial transit time oscillator (TTO) is a promising device to achieve a high-power Ka-band output. However, because the cavity number is limited, the power capacity of extractor and the radiation power are hard to improve. To solve this problem, a high-power Ka-band radial TTO with an over-sized extractor is proposed in this article. Taking the quasi-TM02 mode as working mode, the electric field distribution, beam-loading conductance ratio, and external quality factor prove that the electric field in the extractor can interact with the radial intensity electron beam efficiently. Particle-in-cell (PIC) simulation results prove that a constant magnetic field or decreasing magnetic field can confine electron movement effectively. Setting the imposed diode voltage to be 400 kV, the corresponding current is 7.5 kA, and the microwaves with the power of 1.13 GW, the frequency of 32.15 GHz, and the efficiency of 38% can be generated. When the output power saturates, the maximum radial electric field on the surface of the extractor is only 980 kV/cm, which verified the high-power capacity of the over-sized extractor. Taking ohmic loss into consideration, the proposed radial TTO made of low-loss material (e.g., copper) is potential to output giga-watt level high-power microwaves (HPMs) at Ka-band. [ABSTRACT FROM AUTHOR]

CO2 EOR (enhanced oil recovery) will be one of main technologies of enhanced unconventional resources recovery. Understanding effect of permeability and fractures on the oil mobilization of unconventional resources, i.e. tight oil, is crucial during CO2 EOR process. Exposure experiments based on nuclear magnetic resonance (NMR) were used to study the interaction between CO2 and tight oil reservoirs in Chang 8 layer of Ordos Basin at 40 °C and 12 MPa. Effect of permeability and fractures on oil mobilization of exposure experiments were investigated for the different exposure time. The oil was mobilized from matrix to the surface of matrix and the oil recovery increased as the exposure time increased. The final oil recovery increased as the core permeability increased in these exposure experiments. Exposure area increased to 1.75 times by fractures resulting in that oil was mobilized faster in the initial stage of exposure experiment and the final oil recovery increased to 1.19 times from 28.8 to 34.2%. This study shows the quantitative results of effect of permeability and fractures on oil mobilization of unconventional resources during CO2 EOR, which will support CO2 EOR design in Chang 8 layer of Ordos Basin. [ABSTRACT FROM AUTHOR]

Dual‐ion batteries (DIBs), based on the working mechanism involving the storage of cations and anions separately in the anode and cathode during the charging/discharging process, are of great interest beyond lithium‐ion batteries (LIBs) in high‐efficiency energy storage due to the merits of high working voltage, material availability, as well as low cost and excellent safety. Despite the progress achieved, the practical applications of DIBs are still hindered by negative issues, such as limited capacity and cyclic stability, which triggers the development of suitable electrode materials with highly reversible capacities, and corresponding electrolytes with high oxidative stability as well as sufficient reaction kinetics of active ions. Herein, in this article, a systematic and comprehensive review of fundamentals and recent advances in current DIBs with subcategories of cathode materials, anode materials, and electrolytes are presented. In particular, their energy storage mechanisms, as well as their respective features, are dissected. Furthermore, some strategies and perspectives are proposed for facilitating the further development of DIBs in the future. [ABSTRACT FROM AUTHOR]

Nitrogen (N) fertilization is the major contributor to nitrous oxide (N2O) emissions from agricultural soil, especially in post‐harvest seasons. This study was carried out to investigate whether ryegrass serving as cover crop affects soil N2O emissions and denitrifier community size. A microcosm experiment was conducted with soil planted with perennial ryegrass (Lolium perenne L.) and bare soil, each with four levels of N fertilizer (0, 5, 10 and 20 g N m−2; applied as calcium ammonium nitrate). The closed‐chamber approach was used to measure soil N2O fluxes. Real‐time PCR was used to estimate the biomass of bacteria and fungi and the abundance of genes involved in denitrification in soil. The results showed that the presence of ryegrass decreased the nitrate content in soil. Cumulative N2O emissions of soil with grass were lower than in bare soil at 5 and 10 g N m−2. Fertilization levels did not affect the abundance of soil bacteria and fungi. Soil with grass showed greater abundances of bacteria and fungi, as well as microorganisms carrying narG, napA, nirK, nirS and nosZ clade I genes. It is concluded that ryegrass serving as a cover crop holds the potential to mitigate soil N2O emissions in soils with moderate or high NO3− concentrations. This highlights the importance of cover crops for the reduction of N2O emissions from soil, particularly following N fertilization. Future research should explore the full potential of ryegrass to reduce soil N2O emissions under field conditions as well as in different soils. Highlights: This study was to investigate whether ryegrass serving as cover crop affects soil N2O emissions and denitrifier community size;Plant reduced soil N substrates on one side, but their root exudates stimulated denitrification on the other side;N2O emissions were lower in soil with grass than bare soil at medium fertilizer levels, and growing grass stimulated the proliferation of almost all the denitrifying bacteria except nosZ clade II;Ryegrass serving as a cover crop holds the potential to mitigate soil N2O emissions. [ABSTRACT FROM AUTHOR]

In this study, a tracking and pointing control system with a dual-FSM (fast steering mirror) two-dimensional flexible turntable composite axis is proposed. It is applied to the target-tracking accuracy control in a GI LiDAR (ghost imaging LiDAR) system. Ghost imaging is a multi-measurement imaging method; the dual-FSM GI LiDAR tracking and pointing imaging control system proposed in this study mainly solves the problems of the high-resolution remote sensing imaging of high-speed moving targets and various nonlinear disturbances when this technology is transformed into practical applications. Addressing the detrimental effects of nonlinear disturbances originating from internal flexible mechanisms and assorted external environmental factors on motion control's velocity, stability, and tracking accuracy, a nonlinear active disturbance rejection control (NLADRC) method based on artificial neural networks is advanced. Additionally, to overcome the limitations imposed by receiving aperture constraints in GI LiDAR systems, a novel optical path design for the dual-FSM GI LiDAR tracking and imaging system is put forth. The implementation of the described methodologies culminated in the development of a dual-FSM GI LiDAR tracking and imaging system, which, upon thorough experimental validation, demonstrated significant improvements. Notably, it achieved an improvement in the coarse tracking accuracy from 193.29 μrad (3σ) to 87.21 μrad (3σ) and enhanced the tracking accuracy from 10.1 μrad (σ) to 1.5 μrad (σ) under specified operational parameters. Furthermore, the method notably diminished the overshoot during the target capture process from 28.85% to 12.8%, concurrently facilitating clear recognition of the target contour. This research contributes significantly to the advancement of GI LiDAR technology for practical application, showcasing the potential of the proposed control and design strategies in enhancing system performance in the face of complex disturbances. [ABSTRACT FROM AUTHOR]

Impact tests on post-fire concrete confined by Carbon Fiber-Reinforced Polymer/Plastic (CFRP) sheets were carried out by using Split Hopkinson Pressure Bar (SHPB) experimental setup in this paper, with emphasis on the effect of exposed temperatures, CFRP layers and impact velocities. Firstly, according to the measured stress-strain curves, the effects of experiment parameters on concrete dynamic mechanical performance such as compressive strength, ultimate strain and energy absorption are discussed in details. Additionally, temperature caused a softening effect on the compressive strength of concrete specimens, while CFRP confinement and strain rate play a hardening effect, which can lead to the increase in dynamic compressive strength by 1.8 to 3.6 times compared to static conditions. However, their hardening mechanisms and action stages are extremely different. Finally, nine widely accepted Dynamic Increase Factor (DIF) models considering strain rate effect were summarized, and a simplified model evaluating dynamic compressive strength of post-fire concrete confined by CFRP sheets was proposed, which can provide evidence for engineering emergency repair after fire accidents. [ABSTRACT FROM AUTHOR]