Search

Compacted graphite iron (CGI) is increasingly used in industrial production due to its excellent mechanical property, especially in the field of high-performance automotive engine manufacturing, and has become a substitute for gray cast iron (GCI). However, the hard-to-machine problem caused by its excellent physical properties was the main issue affecting the surface quality of the CGI workpiece. As a new type of tool, the wiper insert could effectively improve the surface quality. In order to develop a long lifespan and high-stability wiper insert tool for CGI milling, this study conducted a series of experiments, including tool design and simulation, coating preparation and testing, and tool cutting performance testing. In the optimization of simulation analysis of tool geometric parameters, it was found that the numerical value of curved cutting-edge radius had a more significant impact on the cutting performance of wiper insert. In the coating test, AlCrN-coated wiper insert C with a coating thickness of 2.84 µm had the best load bearing and fracture toughness performance in the coating mechanic test and had the best coating bonding performance in the scratch test. In the milling experiment with a cutting speed of 125.7 mm/min, a feed rate of 0.15 mm/r, and a cutting depth of 0.5 mm, the coated wiper insert C had the longest tool life and the best machined surface quality of the workpiece. Compared to other coated tools, the tool life was extended by at least 15.7%, and the effective cutting area was increased by 20%, which means it was the most suitable tool for machining CGI. [ABSTRACT FROM AUTHOR]

The Xiachuan site (35°26′22″N, 112°00′43″E) in Shanxi Province, northern China is an important Middle and Upper Paleolithic site, which contains four stages of development: the Middle Paleolithic culture, the initial and early Upper Paleolithic culture, the middle Upper Paleolithic culture and the late Upper Paleolithic culture. To establish the chronology framework for the site, a pedo-stratigraphic sequence at the QX2017T1 survey section of Fuyihegeliang Locality (Loc. FYH) was dated using blue-stimulated optically stimulated luminescence (OSL) on fine-grained quartz and post-infrared infrared stimulated luminescence (post-IR IRSL or pIRIR) on fine-grained polymineral. The quartz OSL ages of the Upper Paleolithic culture layer are between 21.4 ± 1.6 and 42.2 ± 3.0 ka, which is consistent with the calibrated 14C ages. The Middle Paleolithic culture layer is dated to from 118.2 ± 8.5 to 128.3 ± 9.5 ka using the polymineral pIRIR 100, 290 protocol. These new results allow us to put the main part of the Upper Paleolithic culture layer in the late Marine Isotope Stage (MIS) 3 and the early MIS 2, with the Middle Paleolithic culture layer corresponding to the early MIS 5. A gap of nearly 70 ka is observed between the two cultural layers, which is larger than previously expected. The presence of early hominins in the Xiachuan site during MIS 2 and MIS 3 as well as in early interglacial MIS 5 reflects their ability of adapting to variable environments. [ABSTRACT FROM AUTHOR]

Along with the advancement of modern control technology, electric vehicles have gradually become the leading force in the development of the automobile industry. Interior permanent magnet synchronous motors (IPMSMs) have gradually become a mainstream electric vehicle drive component due to their high power density and excellent controllability. This type of motor can form a high-precision closed-loop control system with position sensors, which improves the overall performance. However, the operating conditions are complicated, and position sensor failure can easily occur, which reduces the stability of the motor system. For the fault-tolerant control problem of position sensor failure, pulse high-frequency voltage injection and an improved sliding mode observer (SMO) are employed to achieve the sensorless control of both the low-speed and medium-high-speed sections of the electric motor. Combining the advantages of high-frequency voltage injection in the low-speed section with a high accuracy of position estimation and the advantages of improved SMO in the high-speed section with low computational volume, the composite sensorless control strategy is proposed for IPMSM in the full-speed section. Secondly, an improved SMO using a segmented composite function as the control function is proposed to improve the robustness of the system. It is proposed to address the issue of the smooth transition between the low-speed section and the medium- and high-speed section by using linear weighting. Finally, in order to validate the accuracy of the sensorless control technology, a rapid control prototype of IPMSMs based on Speedgoat is constructed by using a semi-physical simulation system. The efficacy of the control algorithms in the low-speed section, high-speed section and transition interval is verified. [ABSTRACT FROM AUTHOR]

Permanent magnet synchronous motors (PMSMs) are extensively utilized in production and manufacturing fields due to their wide speed range, high output torque, fast speed response, small size and light weight. PMSMs are susceptible to inter-turn short circuit faults, demagnetization faults, bearing faults, and other faults arising from irregular vibrations and frequent start–brake cycles. While fault diagnosis for PMSMs offers an effective means to enhance operational efficiency, the multi-sensor information fusion is often overlooked. In industrial production processes, the collected data inevitably suffers from noise contamination, which can adversely impact diagnostic outcomes. To enhance the robustness of diagnostic methods in noisy environments and mitigate the risk of overfitting, a PMSM fault diagnosis method based on image features of multi-sensor fusion is proposed. Firstly, the vibration acceleration signals of the PMSM at different positions were acquired. Then, the newly designed multi-signal Gramian Angular Difference Fields (MGADF) method combines sensor signals from three different installation locations into a single image. Next, the multi-texture features are fused to extract the features of the image. Various machine models are compared in the fault feature learning and classification, and the results show that the proposed diagnostic method has good diagnostic accuracy and robustness, with an average diagnostic accuracy of 99.54% and a standard deviation of accuracy of 0.19. It has excellent performance even in noisy environments. The method is non-invasive and can be extended and applied to the condition monitoring and diagnosis of industrial motors. [ABSTRACT FROM AUTHOR]

This article is concerned with a chemotaxis-Stokes system with porous medium diffusion and singular sensitivity: { n t + u ⋅ ∇ n = ∇ ⋅ (D (n) ∇ n) − ∇ ⋅ (n S (x , n , c) ⋅ ∇ c) , x ∈ Ω , t > 0 , c t + u ⋅ ∇ c = Δ c − n c , x ∈ Ω , t > 0 , u t + ∇ P = Δ u + n ∇ Φ , ∇ ⋅ u = 0 , x ∈ Ω , t > 0 in a bounded domain Ω ⊂ R N with 2 ≤ N ≤ 3 , where D ∈ C 0 ([ 0 , ∞)) ∩ C 2 ((0 , ∞)) and S ∈ C 2 (Ω ¯ × [ 0 , ∞) 2 ; R N × N) . The global solvability of the system in a natural weak sense is obtained under the conditions that D (n) ≥ k D n m − 1 and | S (x , n , c) | ≤ S 0 (c) c α for all (x , n , c) ∈ Ω × (0 , ∞) 2 with some k D > 0 , m > 3 N − 2 2 N , α ∈ [ 0 , 1) and some nondecreasing S 0 : (0 , ∞) → (0 , ∞) . Moreover, in the case that m = 3 N − 2 2 N and α ∈ [ 0 , 1) , we also get the global weak solutions under smallness assumptions on the initial data ∥ n 0 ∥ L 1 (Ω) and ∥ c 0 ∥ L ∞ (Ω) . [ABSTRACT FROM AUTHOR]

In order to study the comfort of tight-fitting sportswear in winter, this paper designed a series of motions, and explored the distribution of comfort perception under different sports conditions by evaluating the wearing perception of human body. Finally, through the acquired experimental data, intelligent prediction models were established, and the prediction results were visualized, which makes the comfort distribution more intuitive. The results show that there are great differences in the parts that affect the overall comfort perception under different sports conditions; different ages subjects have different perceptions of comfort; Particle Swarm Optimization-Cuckoo Search-Adaptive Network-based Fuzzy Inference System has better prediction accuracy, and could replace the wearing trials. [ABSTRACT FROM AUTHOR]

Simple Summary: The red palm weevil is an exotic and highly endangered pest that is extremely harmful to palm plants. In order to effectively control this pest, we propose an algorithm to automatically detect and count adult red palm weevils in traps. Previously, the trapping and counting of adult red palm weevils was done manually. The population density and damage level were then inferred from the number of adults trapped to guide control efforts. However, the efficiency of this method is very low. The algorithm proposed in this paper solves the drawbacks of manual counting, and the recognition accuracy reaches 93.8%, which also improves the efficiency of agricultural monitoring. The red palm weevil (RPW, Rhynchophorus ferrugineus) is an invasive and highly destructive pest that poses a serious threat to palm plants. To improve the efficiency of adult RPWs' management, an enhanced YOLOv5 object detection algorithm based on an attention mechanism is proposed in this paper. Firstly, the detection capabilities for small targets are enhanced by adding a convolutional layer to the backbone network of YOLOv5 and forming a quadruple down-sampling layer by splicing and down-sampling the convolutional layers. Secondly, the Squeeze-and-Excitation (SE) attention mechanism and Convolutional Block Attention Module (CBAM) attention mechanism are inserted directly before the SPPF structure to improve the feature extraction capability of the model for targets. Then, 2600 images of RPWs in different scenes and forms are collected and organized for data support. These images are divided into a training set, validation set and test set following a ratio of 7:2:1. Finally, an experiment is conducted, demonstrating that the enhanced YOLOv5 algorithm achieves an average precision of 90.1% (mAP@0.5) and a precision of 93.8% (P), which is a significant improvement compared with related models. In conclusion, the enhanced model brings a higher detection accuracy and real-time performance to the RPW-controlled pest pre-detection system, which helps us to take timely preventive and control measures to avoid serious pest infestation. It also provides scalability for other pest pre-detection systems; with the corresponding dataset and training, the algorithm can be adapted to the detection tasks of other pests, which in turn brings a wider range of applications in the field of monitoring and control of agricultural pests. [ABSTRACT FROM AUTHOR]

The effect of Fe defects on carrier recombination and two-photon induced ultrafast exciton dynamics in GaN crystals were investigated using femtosecond transient absorption spectroscopy. The absorption kinetics exhibited completely different characteristics under different nonequilibrium carrier concentrations and distributions. The carrier recombination mechanisms under different excitation conditions can be interpreted by the model of Fe defect-related energy level. The absorption under one-photon excitation originates from the intraband transition of free holes, and the capture of holes by Fe2+ leads to the decay of the absorption. The ultrafast excitonic state [Fe2+,hVB] formation time under two-photon excitation results in a rapid absorption decay (<20 ps), while the long tail of the absorption response could be attributed to long-lived excitonic state (>100 ns). These findings are crucial to the applications of GaN for ultrafast optoelectronics and integrated nonlinear optics. [ABSTRACT FROM AUTHOR]

SUMOylation (SUMO modification) has been confirmed to play an essential role in the progression of various malignancies. As the value of SUMOylation-related genes (SRGs) in prognosis prediction of hepatocellular carcinoma (HCC) has not been explored, we aim to construct an HCC SRGs signature. RNA sequencing was utilized to identify differentially expressed SRGs. The 87 identified genes were used in Univariate Cox regression analysis and the Least Absolute Shrinkage and Selection Operator (LASSO) analysis to build a signature. The accuracy of the model was validated by the ICGC and GEO datasets. The GSEA revealed that the risk score was associated with common cancer-related pathways. The ssGSEA showed that NK cells in the high-risk group were significantly reduced. The sensitivities of anti-cancer drugs confirmed the sensitivity of the high-risk group to sorafenib was lower. Further, our cohort showed that risk scores were correlated with advanced grade and vascular invasion (VI). Finally, the results of H&E staining and immunohistochemistry of Ki67 showed that higher-risk patients are more malignant. [ABSTRACT FROM AUTHOR]

Robot visual servoing controls the motion of a robot through real-time visual observations. Kinematics is a key approach to achieving visual servoing. One key challenge of kinematics-based visual servoing is that it requires time-varying parameter configuration throughout the entire process of one task. Parameter tuning is also necessary when applying to different tasks. The existing work on parameter tuning either lacks adaptation or cannot automate the tuning of all parameters. Meanwhile, the transferability of existing methods from one task to another is low. This work develops a Deep Reinforcement Learning (DRL) framework for robot visual servoing, which can automate all parameters tuning for one task and across tasks. In visual servoing, forward kinematics focuses on motion speed, while inverse kinematics focuses on the smoothness of motion. Therefore, we develop two separate modules in the proposed DRL framework. One tunes time-varying Forward Kinematics parameters to accelerate the motion, and the other tunes the Inverse Kinematics parameters to ensure smoothness. Moreover, we customize a knowledge transfer method to generalize the proposed DRL models to various robot tasks without reconstructing the neural network. We verify the proposed method on simulated robot tasks. The experimental results show that the proposed method outperforms the state-of-the-art methods and manual parameter configuration in terms of movement speed and smoothness in one task and across tasks. [ABSTRACT FROM AUTHOR]

This paper is concerned with a doubly tactic resource consumption model with nonlinear diffusions: u t = ∇ · ((u + 1) h - 1 ∇ u) - ∇ · (u ∇ w) , v t = ∇ · ((v + 1) l - 1 ∇ v) - ∇ · (v ∇ u) , w t = Δ w - (u + v) w - w + r (x , t) , where r is a nonnegative bounded function. This system describes the so-called forager–exploiter interaction. It is shown that if h ≥ 2 - 1 / n and l ≥ 2 , then the system has a global weak solution; if in addition min 1 + 1 / n + (h - 2) + , 1 / n + l - 1 > n / 4 + 1 / 2 , then the system has a unique global classical solution. [ABSTRACT FROM AUTHOR]

This paper reports a simulation-based dynamic confined compression analysis of coral sand under an impact load using the discrete element method (DEM). The evolution of particle breakage on the mesoscale was studied by investigating force chain distributions, crack development, and breakage modes. Crushable sand particles were simulated by replacing rigid particles with flexible basic unit aggregates. The Weibull parameters were incorporated within the mesoscopic parameters of particles, and random numbers were introduced. The obtained results for particle strengths were consistent with the experimental data. The numerical results demonstrated that the force chain was significantly strengthened along the loading axis during loading and weakened during unloading. The cracks were primarily generated along the strong force chain, and particle breakage caused the strong force chain to move towards relatively more complete fragments nearby. The crack was primarily oriented along the loading axis, and its anisotropy was observed to decrease with an increase in the load. Before yielding, particle breakage in the specimen was dominated by attrition at the edges and corners. After yielding, the crack extended into the particle perpendicular to the intergranular contact surface and was deflected by the simultaneous influence of pores. The fracture and shattering of particles occurred successively, and the consequent fall-off and slip filling of the fragments promoted the deformation development. [ABSTRACT FROM AUTHOR]

Osteoporosis is a kind of bone diseases characterized by dynamic imbalance of bone formation and bone absorption, which is prone to fracture, and seriously endangers human health. At present, there is a lack of highly effective drugs for it, and the existing measures all have some side effects. In recent years, mesenchymal stem cell therapy has brought a certain hope for osteoporosis, while shortcomings such as homing difficulty and unstable therapeutic effects limit its application widely. Therefore, it is extremely urgent to find effective and reliable means/drugs for adjuvant stem cell therapy or develop new research techniques. It has been reported that static magnetic fields(SMFs) has a certain alleviating and therapeutic effect on varieties of bone diseases, also promotes the proliferation and osteogenic differentiation of mesenchymal stem cells derived from different tissues to a certain extent. Basing on the above background, this article focuses on the key words "static/constant magnetic field, mesenchymal stem cell, osteoporosis", combined literature and relevant contents were studied to look forward that SMFs has unique advantages in the treatment of osteoporosis with mesenchymal stem cells, which can be used as an application tool to promote the progress of stem cell therapy in clinical application. The brief summary and prospectives of the article. SMFs with different characteristics (intensity and gradient) could synergistically treated osteoporosis by stem cell therapy and underlying mechanisms. SMFs promoted osteogenic differentiation and suppressed adipogenic differentiation of MSCs through a variety of biological mechanisms, such as proliferation, osteogenic differentiation of MSCs, also paracrine effects, autocrine effects and so on. [Display omitted] [ABSTRACT FROM AUTHOR]

Purpose: Herringbone groove thrust bearings are typically used in high-speed, light-load applications, such as spindle motors for hard disk drives. In the past researches, the effect of shaft misalignment was little considered. This study aims to reveal effects of shaft misalignment on the microscopic flow regime in the water-lubricated herringbone groove thrust bearing. Design/methodology/approach: The liquid film in a thrust herringbone groove bearing was investigated by computational fluid dynamics. The effects of micro-grooves on the flow field were carefully explored. Two-dimensional liquid films at four different sites were examined for obtaining the rich flow field properties. Findings: The distributions of pressure, temperature and water vapor volume fraction were obtained, the micro hydrodynamic effects were formed by the herringbone grooves and the effects of the shaft misalignment on lubrication and sealing performance could be found. Originality/value: The influence of misalignment on the herringbone groove thrust bearing performance was investigated in detail. The obtained results could give the reference guideline for the bearing design. [ABSTRACT FROM AUTHOR]

Poly(lactide- co -glycolide) (PLGA) polymers have been widely used for drug delivery due to their biodegradability and biocompatibility. One of the objectives of encapsulating a drug in PLGA microparticles (MPs) is to achieve an extended supply of the drug through sustained release, which can range from weeks to months. Focusing on the applications needing a relatively short-term delivery, we investigated formulation strategies to achieve a drug release from PLGA MPs for two weeks, using meloxicam as a model compound. PLGA MPs produced by the traditional oil/water (O/W) single emulsion method showed only an initial burst release with minimal increase in later-phase drug release. Alternatively, encapsulating meloxicam as solid helped reduce the initial burst release. The inclusion of magnesium hydroxide [Mg(OH) 2 ] enhanced later-phase drug release by neutralizing the developing acidity that limited the drug dissolution. The variation of solid meloxicam and Mg(OH) 2 quantities allowed for flexible control of meloxicam release, yielding MPs with distinct in vitro release kinetics. When subcutaneously injected into rats, the MPs with relatively slow in vitro drug release kinetics showed in vivo drug absorption profiles consistent with in vitro trend. However, the MPs that rapidly released meloxicam showed an attenuated in vivo absorption, suggesting premature precipitation of fast-released meloxicam. In summary, this study demonstrated the feasibility of controlling drug release from the PLGA MPs over weeks based on the physical state of the encapsulated drug and the inclusion of Mg(OH) 2 to neutralize the microenvironmental pH of the MPs. [Display omitted] • Meloxicam was encapsulated in PLGA microparticles for sustained release over 2 weeks. • Encapsulation of meloxicam in the solid state reduced the initial burst release. • Inclusion of Mg(OH) 2 enhanced drug release in the later phase. • Microparticles showed a consistent trend in in vivo drug absorption as in vitro results when the release was relatively slow. [ABSTRACT FROM AUTHOR]

The variational optical flow model is used in this work to investigate a subgrid-scale optimization approach for modeling complex fluid flows in image sequences and estimating their two-dimensional velocity fields. To solve the problem of lack of sub-grid small-scale structure information in variational optical flow estimation, we combine the motion laws of incompressible fluids. Introducing the idea of large eddy simulation, the instantaneous motion can be decomposed into large-scale motion and a small-scale turbulence in the data term. The Smagorinsky model is used to model and solve the small-scale turbulence. The improved subgrid scale Horn–Schunck (SGS-HS) optical flow algorithm provides better results in velocity field estimation of turbulent image sequences than the traditional Farneback dense optical flow algorithm. To make the SGS-HS algorithm equally competent for the open channel flow measurement task, a velocity gradient constraint is chosen for the canonical term of the model, which is used to improve the accuracy of the SGS-HS algorithm in velocimetric experiments in the case of the relatively uniform flow direction of the open channel flow field. The experimental results show that our algorithm has better performance in open channel velocimetry compared with the conventional algorithm. [ABSTRACT FROM AUTHOR]

In this paper, a scheme of optical encryption system for color code is proposed which is based on double random polarization encryption and exclusive-OR operation. First, an original image is generated into a color code according to the rules of color code generation, then the color code is encoded by exclusive-OR operation, finally, the coded color code is used as the input image for double-random polarization encryption. The original image can be recovered only if all the keys are correct. If the ciphertext is tampered or cut, the image cannot be recovered or even displayed on the computer. This method can apply the double random polarization encryption method used for binary image encryption to color code encryption, and the exclusive-OR operation can improve the security of the system. Numerical experimental results show the feasibility and effectiveness of this method. [ABSTRACT FROM AUTHOR]

We report two-photon excited ultrafast carrier trapping and recombination in n-type β-Ga2O3 crystals by using femtosecond transient absorption spectroscopy. The broadband absorption spectra arising from the defect are polarization dependent, especially, two absorption peaks can be observed by subtracting the absorption transients under two probe polarizations. We attribute these observed defect-related absorption features to optical transitions from the valence band to different charge states of a native defect (such as gallium vacancies). A model for carrier capture by multilevel of a single defect is proposed to interpret the data, wherein holes are captured more efficiently than electrons by the defects, and the absorption cross sections for the defects are at least ten times larger than that for free carriers. Our results reveal the potential applications of β-Ga2O3 in ultrafast and broadband optoelectronic devices. [ABSTRACT FROM AUTHOR]

Agonists of the cyclic guanosine monophosphate–adenosine monophosphate synthase (cGAS)-Stimulator of Interferon Genes (STING) pathway, a critical mediator of innate immune response to foreign invaders with DNA, have gained significant interest in cancer immunotherapy. STING agonists are envisioned as a way of complementing the antitumor activity of the patient's immune system and immune checkpoint blockade therapy. However, their clinical development has been challenging due to the poor pharmacokinetic and physicochemical properties. This review discusses drug delivery efforts to circumvent the challenges, their accomplishment, and unmet needs based on the last five years of literature. • STING agonists can enhance cancer immunotherapy. • STING agonists have unfavorable pharmacokinetic and physicochemical properties. • Particles, hydrogels, cells, and antibodies are used to improve STING agonist delivery. [ABSTRACT FROM AUTHOR]

Objective. Accumulated evidence highlights the biological implications of exosomes in gastric cancer. Herein, we conducted the exosomal miRNA expression profiling and identified potential diagnostic markers for gastric cancer. Methods. Plasma exosomes were isolated and identified from three gastric cancer patients and three healthy participants. Microarrays of exosomal miRNAs were then analyzed. Differentially expressed exosomal miRNAs were screened with fold − change ≥ 2.0 and p ≤ 0.05. Among them, miR-4741, miR-32, miR-3149, and miR-6727 expressions were verified in tissues and plasma of patients and healthy subjects. ROC curves were conducted for evaluating the diagnostic performance. The roles of miR-32, miR-3149, miR-6727, and miR-4741 on gastric cancer progression were observed by cellular experiments. Results. Isolated exosomes were well characterized by Western blot and transmission electron microscopy as well as nanoparticle-tracking analyses. According to the microarrays, 142 exosomal miRNAs were upregulated, and 34 were downregulated in gastric cancer than healthy subjects. miR-4741 upregulation and miR-32, miR-3149, and miR-6727 downregulations were found in tissues and plasma of gastric cancer patients. The AUCs of miR-4741, miR-32, miR-3149, and miR-6727 were separately 0.8554, 0.9456, 0.7683, and 0.8923. Upregulated miR-32, miR-3149, and miR-6727 as well as downregulated miR-4741 lowered proliferative, migratory, and invasive capacities as well as elevated apoptotic levels of gastric cancer cells. Conclusion. Our study successfully isolated and verified exosomes from plasma of gastric cancer as well as proposed four exosomal miRNAs that could act as promising diagnostic markers and suppress gastric cancer progression. [ABSTRACT FROM AUTHOR]

The location of the entrance pupil, field of view, and motion of the viewer's eye is frequently discussed for virtual reality/augmented reality (VR/AR) displays. In order to properly measure optical performance of these displays, the light measuring device (LMD) must simulate the characteristics of the human eye. An important factor to consider is the location of the entrance pupil (aperture stop setting) of the LMD. We compared field of view (FOV) and luminance deviations with various pupil entrance locations at the LMD in this paper. As a result of the experiment, the entrance pupil at the front focal point of the LMD was the best choice. [ABSTRACT FROM AUTHOR]

Graphyne (GYs) is a class of 2D carbon allotropes with highly π-conjugated structure consisting of sp- and sp2-hybridized carbon atoms, leading to unique molecular configuration and electronic structure, showing excellent electrical, mechanical, photoelectric and semiconducting properties, and having great potentials in gas–separation, chemical-reaction catalysis, energy–storage, and sensor applications. GYs can be classified into several structural forms, including graphdiyne (GDY) and graphtriyne (GTY). Structural characterisation is crucial for understanding the relationship between their structure and properties. At present, quite a few experimental methods, including scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, nuclear magnetic resonance, infrared and Raman spectroscopies, have been used to characterise the structure of GYs. This review focuses on the structural and vibrational characterisations of GYs using Infrared (IR) and Raman spectroscopies. The vibrational signature, including linear and nonlinear IR characteristics of the periodically appearing C ≡ C bond, will be reviewed. The intensity enhanced C ≡ C stretching mode as an IR marker in monitoring vibrational energy redistribution and transfer in GYs will be discussed. This review will shed light on the understanding of the structures and structural distributions, and vibrational energy-transfer pathways of the GY systems, which are important for their design, fabrication and applications. [ABSTRACT FROM AUTHOR]

Semiautomated digital creation is increasingly important in the manipulation of electronic music. How to realize the learning of local effective features of audio data is a difficult point in the current research field. Based on recurrent neural network theory, this paper designs a semiautomatic digital creation system for electronic music for digital manipulation and genre classification. The recurrent neural network improves the transmission of electronic music information between the input and output of the network by adopting dense connections consistent with DenseNet and adopts an inception-like structure for the autonomous selection of effective recursive nuclear electronic music categories. In the simulation process, the prediction method based on semiautomatic digital audio clips is also adopted, which pays more attention to the learning of local effective features of audio data, which gives the model the ability to create audio samples of different lengths and improves the model's support for creative tasks in different scenarios. It includes the determination of the number of neurons, the selection of the function of neurons, the determination of the connection method, and the specific learning algorithm rules, and then the training samples are formed. The experimental results show that the recurrent neural network exhibits powerful feature extraction ability and classification ability of music information. The 10-fold cross-validation on GTZAN dataset and ISMIR2004 dataset has obtained 88.7% and 87.68%, surpassing similar ones. The model has reached a leading level. After further use of the MSD (Million Song Dataset) dataset for pre-semiautomatic training, the model effect has been further greatly improved. The accuracy rate on the dataset has been increased to 91.0% and 89.91%, respectively, which has improved the semiautomatic number and creative advancement. [ABSTRACT FROM AUTHOR]

In this article, a novel vehicle-mounted magnetic suspension flywheel battery with a virtual inertia spindle is proposed, which has the advantages of high integration, superior energy storage characteristics, high safety, and stability. Different from the traditional flywheel battery with inertia spindle structure through the motor and flywheel, the novel flywheel battery has no inertia spindle, but has a pillar integrated with the flywheel instead. The pillar does not run through the flywheel, magnetic bearings and motor at all, therefore it does not play the role of supporting the above key components like the traditional inertia spindle, but just for convenient detection and safety protection. Therefore, the existence of the pillar is not the inertia spindle, but just looks like it, so it is called virtual inertia spindle. The unique flywheel structure after optimization can make the energy storage characteristics and the integration of flywheel battery improve obviously. In addition, because of the spherical element, the flywheel supported by the high-integration magnetic bearing has the advantage of not being easily affected by external interference produced by running conditions. To prove the validity of the proposed flywheel battery topology and correctness of theoretical analysis, the stiffness and performance tests are carried out. The experiments results show that the flywheel battery system exhibits superior antiinterference characteristic. [ABSTRACT FROM AUTHOR]

Accurate assessment of wet aggregate stability is critical in evaluating soil quality. However, a few general models are used to assess it. In this work, we use the support vector machine to evaluate wet aggregate stability and compare it with a benchmark model based on artificial neural networks. One hundred thirty-four soil samples from various land uses, such as crops, grasslands, and bare land are adopted to verify the effectiveness of the proposed method and confirm the valid input parameters. We select 107 samples for calibrating the prediction model and the rest for evaluation. Experiments show that organic carbon is the main control parameter of wet aggregate stability, although the most influential factors for different land use are various. Comparing the determination coefficient and the root mean square error, it proves that the support vector machine method is superior to the artificial neural network method. In addition, the relative importance analysis shows that contents of organic carbon, silt, and clay are the primary input parameters. Finally, the impact of land use and management types is evaluated. [ABSTRACT FROM AUTHOR]

Chemical sensing for the sensitive and reliable detection of mercury(II) ions (Hg2+) is of great importance in environmental protection, food safety, and biomedical applications. Due to the bio-enrichment property of Hg2+ in organisms, it is particularly meaningful to develop an effective tool that can in situ and rapidly monitor the level of Hg2+ in living organisms. In this work, we report ligand functionalized gold-silver bimetallic nanoclusters with bright red fluorescence as intracellular probes for imaging Hg2+ in living cells and zebrafish. The bimetallic nanoclusters of DTT-GSH@Au/AgNCs (DG-Au/AgNCs) with strong fluorescence that benefited from the synergistic effect of Au and Ag atoms were obtained through a one-pot synthesis method, incorporating glutathione (GSH) and dithiothreitol (DTT) as the reducers and functionalized ligands. Attractively, the bright red fluorescence of DG-Au/AgNCs could be rapidly and selectively quenched by Hg2+ within 1 min with a very low detection limit of 1.01 nM. Additionally, DG-Au/AgNCs had a great advantage in the detection of Hg2+ in living cells and zebrafish owing to its notably strong red fluorescence at 665 nm, which could avoid effectively auto-fluorescence interference from the organism. Such easily prepared bimetallic fluorescent nanoclusters would be expected to provide a noninvasive and sensitive approach in the detection of heavy metals in situ for environmental protection. [ABSTRACT FROM AUTHOR]

To explore the impact of the sintering rate on the microstructure and mechanical properties of cermets, the preparation of (Ti,W)C cermets by ultrafast sintering via spark plasma sintering (SPS) is reported. Compared with a slow heating rate, the electric field produced by an ultrafast heating rate enhances the liquid phase mass transfer of the metal binder phase, thus achieving rapid densification of (Ti,W)C cermets and effectively inhibiting abnormal grain growth. However, an excessive heating rate will lead to an "overflow" phenomenon, which reduces the grain growth difficulty and the bonding strength between grains. The results show that when the heating rate is 500 °C/min, the liquid phase mass transfer is moderate, the densification degree is the highest and the mechanical properties are excellent. The flexural strength, Vickers hardness and fracture toughness are 1340.90 ± 23.55 MPa, 18.42 ± 0.46 GPa and 11.96 ± 0.23 MPa∙m1/2, respectively. [ABSTRACT FROM AUTHOR]

The large screens used in stadiums, shopping malls, and movie theaters typically have multiple viewers looking at them simultaneously. The quantification of these displays' image quality would require more considerations of measurements at different locations to satisfy the multiviewing condition. In this paper, we describe the practical implementation method involved in the current standardization activities. Additionally, a vantage point measurement method is studied. In the actual use case scenarios, the vantage point method is more appropriate. This method mimics the viewing behavior of audiences. The displays we measured were laser projection and LED. The method shows validity in both displays. Using the vantage point method, the experimental data show that the existing large displays may have very prominent differences in luminance and chromaticity at different viewing locations. [ABSTRACT FROM AUTHOR]

With the continuous in-depth development of oil and gas resources, unconventional oil and gas resources show great potential. In recent years, 70% of the proven oil and gas resources in China are unconventional oil and gas resources. Therefore, the development of unconventional oil and gas resources has a huge impact on the increase in the production capacity of the oil and gas resources in China. Staged fracturing of horizontal wells is the main technical measure to improve unconventional oil and gas production stimulation. In the fracturing process, the soluble bridge plug technology can not only effectively solve the problems of large investment in drilling and grinding of composite bridge plugs, high risks, self-locking of oil, casing deformation, etc., causing the bridge plug to be unable to be drilled and remove and affect subsequent production but also can successfully make up for the problems of subsequent production. The large-diameter bridge plug cannot achieve the full diameter of the wellbore and cannot carry out operations such as postproduction logging and refracturing, which can ensure the integrity of the wellbore to the greatest extent. In this paper, HNBR was used to modify MPU to prepare HNBR/MPU soluble rubber, and the effect of blending ratio on the vulcanization characteristics, mechanical properties, compatibility, thermal stability, and degradation behavior of composites was studied. The results showed that with the increase in the amount of HNBR, the degree of cross-linking of the composite material decreased gradually, and the mechanical properties decreased slightly. With the increase in the amount of HNBR, the thermal stability of the material decreases. The use of HNBR greatly reduced the degradation rate of MPU. When the amount of HNBR was changed from 20 phr to 40 phr, the tensile strength retention rate of the composite after soaking increased from 14.73% to 39.72%. [ABSTRACT FROM AUTHOR]

A group of nucleic acids and oligonucleotides play various roles in the innate immune system. They can stimulate pattern recognition receptors to activate innate immune cells, encode immunostimulatory proteins or peptides, or silence specific genes to block negative regulators of immune cells. Given the limitations of current cancer immunotherapy, there has been increasing interest in harnessing innate immune responses by nucleic acids and oligonucleotides. The poor biopharmaceutical properties of nucleic acids and oligonucleotides make it critical to use carriers that can protect them in circulation, retain them in the tumor microenvironment, and bring them to intracellular targets. Therefore, various gene carriers have been repurposed to deliver nucleic acids and oligonucleotides for cancer immunotherapy and improve their safety and activity. Here, we review recent studies that employed carriers to enhance the functions of nucleic acids and oligonucleotides and overall immune responses to cancer, and discuss remaining challenges and future opportunities in the development of nucleic acid-based immunotherapeutics. [Display omitted] [ABSTRACT FROM AUTHOR]

Hong Kong has experienced a steady decline in mortality during the past several decades, and Hong Kong now life expectancy are among the highest in the world. Given the very low mortality already achieved, is there much more room for further improvement in Hong Kong's mortality decline? This paper examined how age-specific mortality by sex in Hong Kong has changed over time, and applied the Lee–Carter model to mortality projections in Hong Kong for next 50 years. When using Lee–Carter model, we dealt with the possible divergence in mortality projection for males and females over time, and take a shorter projection base period to meet the assumption of the parameters describing the age pattern of mortality decline being invariant. If we compare the results with the most recent official forecasts, projections on mortality decline in this paper are more optimistic than the official forecasts. [ABSTRACT FROM AUTHOR]

Time synchronization is the basis of coordination and cooperation in underwater acoustic networks. However, because of the propagation delay, node mobility, and Doppler shift, it is impossible to balance the accuracy and energy consumption simply in water. As a promising technology, partial clustering has high convergence and makes breakthroughs in time synchronization. This paper proposes PCDE-Sync, a novel synchronization mechanism with partial clustering and the Doppler effect. Firstly, a clustering method built on the artificial fish swarm algorithm is presented. It models the cluster construction according to fish's preying, swarming, and following behaviors. Secondly, we design a synchronization mechanism to conduct clock correction and compensation by the Doppler effect. Finally, we compare the performance of PCDE-Sync with the most advanced protocols, namely MU-Sync, MM-Sync, and DE-Sync, in terms of the cumulative error after synchronization, the mean square error under different clock skew and that under distinctive node mobility, and energy consumption. The experimental results show that PCDE-Sync makes a trade-off between accuracy and complexity, which does well in solving synchronization issues. [ABSTRACT FROM AUTHOR]

In the defect diagnosis of the gear-shaft-bearing system with compound defects, the generated vibration signals are complicated. In addition, the information acquired by a single sensor is easily affected by uncertain factors, and low diagnostic accuracy is caused when traditional defect diagnosis methods are used, which cannot meet the high-precision diagnosis requirements. Therefore, a method is developed to identify the defect types and defect degrees of the gear-shaft-bearing system efficiently. In this method, the vibration signals are collected using multiple sensors, the dual-tree complex wavelet and the optimal weighting factor (OWF) methods are used for the data layer fusion, and the preprocessing is realized through wavelet transform and FFT. A learning model based on two-stream CNN composed of 1D-CNN and 2D-CNN is established, and the obtained wavelet time-frequency map and FFT spectrum are used as the input. Then, the trained features from the output of the connected layer are classified by the SVM. Compared with the OWF-1DCNN and OWF-2DCNN models, the time consumption of the OWF-TSCNN model is increased by 14.5%–26.6%, and the convergence speed of the network is decreased. However, its accuracy reaches 100% and 99.83% in the training set and test set, and the loss entropy and over-fitting rate are also greatly reduced. The feature extraction ability and generalization ability of the OWF-TSCNN model are increased, reaching 100% diagnosis accuracy on different defect types and defect degrees, which is more suitable for defect diagnosis of the gear-shaft-bearing system. [ABSTRACT FROM AUTHOR]

The Duobaoshan Cu (Mo) deposit is one of the oldest super large porphyry deposits in the eastern part of the Central Asian orogenic belt. Although ore-forming processes have been extensively concerned, the post-mineralization ore preservation state was poorly focused on. In order to improve the ability of prospecting forecast, it is necessary to consider both deposit formation and deposit preservation. Here, we reported apatite fission track (AFT) data for the Duobaoshan porphyry copper deposits in the belt to reveal the cooling and exhumation history and evaluate ore preservation. The results show that the rapid cooling of the ore-hosting rock body occurred later than the surrounding rock body. The rapid cooling of the surrounding granodiorite occurred between 82 and 72 Ma, with the exhumation depth of 2.33–3.11 km and the exhumation rate of 0.25 mm/a, whereas the ore-hosting granodiorite porphyry was rapid cooling between 71.8 and 50.2 Ma, with the exhumation depth of 2.99–3.86 km and the exhumation rate of 0.22 mm/a. This differential exhumation and cooling event provide favorable geological conditions for the preservation of the ore body. [ABSTRACT FROM AUTHOR]

A gradient nano self-lubricating ceramic cutting tool material was prepared by vacuum hot-pressing sintering technique. The composition of each layer is designed in a gradient so that the nano-sized solid lubricant content is gradually reduced from the surface to the center, and residual compressive stresses are formed in the tool surface. The components and microstructure of the prepared ceramic tools showed gradient changes, with clear and well-bonded interfaces between the gradient layers. Compared with the mechanical properties of homogeneous tool, the flexural strength, fracture toughness, and hardness of this ceramic tool were increased by 74.0%, 3.9%, and 5.0%, respectively. The gradient design had little effect on the friction coefficient, but the improved mechanical properties and the presence of residual compressive stresses in the surface layer improved the wear resistance of the tool. The higher the friction speed and load, the more effectively the gradient design will improve the wear rate. [ABSTRACT FROM AUTHOR]

Background: Interpretation bias (IB), pre- and post-event rumination are related to adolescent social anxiety (SA). However, although postulated theoretically, the mediating role of pre- and post-event rumination between IB and SA has not been examined in adolescents. In addition, post-event rumination was found to differ in varying social situations (e.g., speech vs. interaction). Therefore, by establishing social tasks, the current research investigated whether: (i) pre- and post-event rumination mediated the association between IB and SA among adolescents, and (ii) this mediation was moderated by situational type.In Study 1, 31 socially anxious adolescents and 37 controls were recruited and then primed with a speech task. In Study 2, 61 socially anxious adolescents were randomly assigned to a speech (n = 31) or interaction (n = 30) task. In both studies, baseline IB and SA, state pre-event rumination before starting the social task, post-event rumination and SA after social task were measured.IB affected adolescents’ SA via pre- and post-event rumination; however, the mediation effect was found only in the speech task.Findings provide potential approaches for reducing adolescent SA by targeting IB and rumination and showed the situational adaptability of the cognitive model of social anxiety disorder among adolescents.Methods: Interpretation bias (IB), pre- and post-event rumination are related to adolescent social anxiety (SA). However, although postulated theoretically, the mediating role of pre- and post-event rumination between IB and SA has not been examined in adolescents. In addition, post-event rumination was found to differ in varying social situations (e.g., speech vs. interaction). Therefore, by establishing social tasks, the current research investigated whether: (i) pre- and post-event rumination mediated the association between IB and SA among adolescents, and (ii) this mediation was moderated by situational type.In Study 1, 31 socially anxious adolescents and 37 controls were recruited and then primed with a speech task. In Study 2, 61 socially anxious adolescents were randomly assigned to a speech (n = 31) or interaction (n = 30) task. In both studies, baseline IB and SA, state pre-event rumination before starting the social task, post-event rumination and SA after social task were measured.IB affected adolescents’ SA via pre- and post-event rumination; however, the mediation effect was found only in the speech task.Findings provide potential approaches for reducing adolescent SA by targeting IB and rumination and showed the situational adaptability of the cognitive model of social anxiety disorder among adolescents.Results: Interpretation bias (IB), pre- and post-event rumination are related to adolescent social anxiety (SA). However, although postulated theoretically, the mediating role of pre- and post-event rumination between IB and SA has not been examined in adolescents. In addition, post-event rumination was found to differ in varying social situations (e.g., speech vs. interaction). Therefore, by establishing social tasks, the current research investigated whether: (i) pre- and post-event rumination mediated the association between IB and SA among adolescents, and (ii) this mediation was moderated by situational type.In Study 1, 31 socially anxious adolescents and 37 controls were recruited and then primed with a speech task. In Study 2, 61 socially anxious adolescents were randomly assigned to a speech (n = 31) or interaction (n = 30) task. In both studies, baseline IB and SA, state pre-event rumination before starting the social task, post-event rumination and SA after social task were measured.IB affected adolescents’ SA via pre- and post-event rumination; however, the mediation effect was found only in the speech task.Findings provide potential approaches for reducing adolescent SA by targeting IB and rumination and showed the situational adaptability of the cognitive model of social anxiety disorder among adolescents.Conclusions: Interpretation bias (IB), pre- and post-event rumination are related to adolescent social anxiety (SA). However, although postulated theoretically, the mediating role of pre- and post-event rumination between IB and SA has not been examined in adolescents. In addition, post-event rumination was found to differ in varying social situations (e.g., speech vs. interaction). Therefore, by establishing social tasks, the current research investigated whether: (i) pre- and post-event rumination mediated the association between IB and SA among adolescents, and (ii) this mediation was moderated by situational type.In Study 1, 31 socially anxious adolescents and 37 controls were recruited and then primed with a speech task. In Study 2, 61 socially anxious adolescents were randomly assigned to a speech (n = 31) or interaction (n = 30) task. In both studies, baseline IB and SA, state pre-event rumination before starting the social task, post-event rumination and SA after social task were measured.IB affected adolescents’ SA via pre- and post-event rumination; however, the mediation effect was found only in the speech task.Findings provide potential approaches for reducing adolescent SA by targeting IB and rumination and showed the situational adaptability of the cognitive model of social anxiety disorder among adolescents. [ABSTRACT FROM AUTHOR]

We study a doubly tactic resource consumption model (ut = Δu − ∇ · (u∇w), vt = Δv − ∇ · (v∇u) + v(1 − vβ−1), wt = Δw − (u + v)w − w + r) in a smooth bounded domain Ω ∈ R 2 with homogeneous Neumann boundary conditions, where r ∈ C 1 ( Ω ̄ × [ 0 , ∞)) ∩ L ∞ (Ω × (0 , ∞)) is a given non-negative function fulfilling ∫ t t + 1 ∫ Ω | ∇ r | 2 < ∞ for all t ≥ 0. It is shown that, first, if β > 2, then the corresponding Neumann initial-boundary problem admits a global bounded classical solution. Second, when β = 2, the Neumann initial-boundary problem admits a global generalized solution. [ABSTRACT FROM AUTHOR]

In this paper, the interference mitigation for Frequency Modulated Continuous Wave (FMCW) radar system with a dechirping receiver is investigated. After dechirping operation, the scattered signals from targets result in beat signals, i.e., the sum of complex exponentials while the interferences lead to chirp-like short pulses. Taking advantage of these different time and frequency features between the useful signals and the interferences, the interference mitigation is formulated as an optimization problem: a sparse and low-rank decomposition of a Hankel matrix constructed by lifting the measurements. Then, an iterative optimization algorithm is proposed to tackle it by exploiting the Alternating Direction of Multipliers (ADMM) scheme. Compared to the existing methods, the proposed approach does not need to detect the interference and also improves the estimation accuracy of the separated useful signals. Both numerical simulations with point-like targets and experiment results with distributed targets (i.e., raindrops) are presented to demonstrate and verify its performance. The results show that the proposed approach is generally applicable for interference mitigation in both stationary and moving target scenarios. [ABSTRACT FROM AUTHOR]

A novel matrix-pencil (MP)-based interference mitigation approach for frequency-modulated continuous-wave (FMCW) radars is proposed in this article. The interference-contaminated segment of the beat signal is first cut out, and then, the signal samples in the cutout region are reconstructed by modeling the beat signal as a sum of complex exponentials and using the MP method to estimate their parameters. The efficiency of the proposed approach for the interference with different parameters (i.e., interference duration, signal-to-noise ratio (SNR), and different target scenarios) is investigated by means of numerical simulations. The proposed interference mitigation approach is intensively verified on experimental data. Comparisons of the proposed approach with the zeroing and other beat-frequency interpolation techniques are presented. The results indicate the broad applicability and superiority of the proposed approach, especially in low SNR and long interference duration situations. [ABSTRACT FROM AUTHOR]

Aiming to solve the problems of long transmission chain, large movement inertia of components and high energy consumption of pumping units, this proposes a new pumping unit with direct balance and hydraulic drive. Through mathematical modeling and simulation analysis to compare the suspension dynamic characteristics and balance characteristics of the hydraulically driven pumping unit with the conventional one. It turns out that the suspension maximum speed drop 21.14%, the maximum acceleration drops 28.88% and the root mean square torque drops 92.9% on the suspension of the hydraulically driven pumping unit. The experimental results proves that the hydraulically driven pumping unit has significant energy saving efficiency, and achieves more than 30.9% of active power saving rate. Theoretical and practical research results show that hydraulically driven pumping unit is reliable and better energy saving, which provides a basis in theory and engineering practice in application. [ABSTRACT FROM AUTHOR]

We study a forager-exploiter model with nonlinear diffusions { u t = ∇ ⋅ ((u + 1) m ∇ u) − ∇ ⋅ (u ∇ w) , v t = ∇ ⋅ ((v + 1) l ∇ v) − ∇ ⋅ (v ∇ u) , w t = Δ w − (u + v) w − μ w + r in a smooth bounded domain Ω ∈ R n with homogeneous Neumann boundary conditions, where μ > 0 and r is a given nonnegative function. We prove that, if m ≥ 1 and l ∈ [ 1 , ∞) ∩ (n (n + 2) 2 (n + 1) , ∞) , then the classical solution exists globally and remains bounded. [ABSTRACT FROM AUTHOR]

Pu-erh tea theabrownins (TBs) exert beneficial effect on egg quality and antioxidant properties of eggs, but the underlying mechanisms behind this response are unclear. In this study, we investigate the effect of TBs on egg antioxidative activity, amino acid and fatty acid profiles, and the underlying relationship between the TBs and oxidant-sensitive Nrf2 signaling pathway in laying hens. Eighty layers were fed a basal diet (control) and 400 mg/kg of TBs supplemented diet for 12 wk. TBs led to an increase in albumen height and Haugh unit (P < 0.05). The albumen lysine, valine, and tryptophan were higher in layers fed TBs, whereas yolk tryptophan, methionine, vitamin A, and α-tocopherol content were enhanced by TBs (P < 0.05). Eggs albumen and yolk showed higher total antioxidant capacity (T-AOC), reducing power (RP), and the scavenging rate of 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH), and lower MDA content than those of eggs from the control group (P < 0.05). Also, magnum Nrf2 , hemeoxygenase 1 ( HO-1 ), NAD(P)H quinone dehydrogenase 1 ( NQO1 ), and Bcl2 expression were up-regulated by TBs, whereas magnum proapoptotic gene (Bax, caspase 3, Cyt C) were down-regulated by TBs (P < 0.05). Our findings suggest that TBs improved egg albumen quality and antioxidant activity, and the Nrf2-ARE pathway were found to be involved in this process. [ABSTRACT FROM AUTHOR]

Multi-object spectroscopy has become a valuable technique in numerous modern astronomical facilities. Most spectrographs have thousands of fibre positioners packed at a focal plane with shared working space. Therefore, positioners might collide with each other, which can lead to them being damaged. In this study, we first analysed the types of collisions between hexagonal patterned theta–phi positioners and the possibility of these collisions. Based on this, we proposed a motion planning method by deploying a proposed 'safety zone' within the positioner patrol area. Simulated experiments validated that our method could completely solve collisions between positioners with equal arms, such as the Large-sky-Area Multi-Object fibre Spectroscopic Telescope (LAMOST) and the Dark Energy Spectroscopic Instrument (DESI), or between positioners with unequal arms, such as the Multi-Object Optical and Near-infrared Spectrograph (MOONS). [ABSTRACT FROM AUTHOR]

Multiple-input multiple-output is a commonly used technology supporting for high-rate transmission over frequency-selective fading channels with multiple antennas. Vertical-Bell Laboratories Layered Space-Time is a detection method of a multiple-input multiple-output system, which establishes a direct correspondence between antennas and layers. Studies demonstrate that multiple-input multiple-output Vertical-Bell Laboratories Layered Space-Time is a meaningful way for underwater acoustic networks of high performance. However, considering the hardware constraints and energy consumption, achieving a trade-off between the bit error ratio and complexity is a crucial issue for underwater acoustic networks of multiple-input multiple-output Vertical-Bell Laboratories Layered Space-Time systems. This article proposes a novel signal detection algorithm of multiple-input multiple-output Vertical-Bell Laboratories Layered Space-Time. First, we address the unitary matrix of the underwater acoustic channel by LDLH decomposition. Second, we order the detection sequence based on the permutation matrix. Third, we detail the implementation of interference cancelation and slice processing. Finally, we perform experiments for comparing the bit error ratio, energy consumption, processing delay, and complexity of the proposed algorithm with zero-forcing Vertical-Bell Laboratories Layered Space-Time, minimum mean square error Vertical-Bell Laboratories Layered Space-Time, and maximum likelihood Vertical-Bell Laboratories Layered Space-Time. Results indicate that our algorithm maintains bit error ratio and the processing delay to that of maximum likelihood Vertical-Bell Laboratories Layered Space-Time algorithm. However, it reduces the energy consumption, which achieves a good trade-off between performance and complexity. This work supports on constructing underwater acoustic networks of multiple-input multiple-output Vertical-Bell Laboratories Layered Space-Time system. [ABSTRACT FROM AUTHOR]

This paper concerns with a reaction–diffusion system modeling the population dynamics of the predator and prey, in which the predator moves toward the gradient of concentration of some chemical released by prey instead of moving directly toward the higher density of prey. The first objective is to investigate the global existence and boundedness of the unique classical solution. Then we study the asymptotic stabilities of nonnegative spatially homogeneous equilibria. Moreover, the convergence rates are also studied. [ABSTRACT FROM AUTHOR]

In order to improve the light extraction for the deep ultraviolet light emitting diodes (DUV-LEDs), the surface microstructure based on a parabola cone array is used and optimized in work. In the optimization of the surface structure, inverse design based on a particle swarm optimization intelligent algorithm is applied to maximize the light extraction. The optimization results show that compared with the traditional planar structure, the optimized surface structure improves the light extraction efficiency by more than 200%. In addition, the influence of the designed surface microstructure on the light propagation is also explored by comparing the light field distribution and the light extraction process with the planar structure DUV-LEDs. It is revealed that the high aspect ratio of an array microstructure can change the light propagation and greatly expand the angle of a light escape cone. This effect can be maximized by the inverse design based on the intelligent algorithm, which has great potential in improving the light extraction of AlGaN-based DUV-LEDs. [ABSTRACT FROM AUTHOR]

3-D imaging with irregular planar multiple-input-multiple-output (MIMO) arrays is discussed. Due to signal acquisition on irregular spatial sampling grids by using these antenna arrays, the fast Fourier transform (FFT)-based imaging algorithms cannot readily be used for image formation. To avoid the application of computationally intensive coherent summation algorithms such as filtered backprojection or Kirchhoff migration, we propose a nonuniform FFT (NUFFT)-based MIMO Range Migration Algorithm (i.e., NUFFT-based MIMO-RMA) for efficient microwave imaging. The algorithm exploits NUFFT to reconstruct the wavenumber–domain spectra related to each Fourier frequency. It is generic and applicable to 3-D imaging with irregular planar MIMO arrays. The effects of irregular spatial sampling and signal bandwidth on the imaging performance and computational efficiency of the proposed algorithm are analyzed. Finally, some numerical simulations and experimental results are presented to demonstrate the performance of the proposed imaging algorithm. [ABSTRACT FROM AUTHOR]