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This paper presents a study on the integral equation method and the Nystöm method for the scattering of time-harmonic acoustic waves by a two-layered medium with an unbounded perturbed boundary. The medium consists of two layers separated by a plane interface, for which we assume transmission boundary conditions. We assume either Dirichlet or impedance boundary conditions for the rough surface boundary. Unlike classical rough surface scattering problems, the presence of a plane interface makes it difficult to establish the well-posedness of the scattering problem and to find a numerical treatment. We introduce the two-layered Green function and prove that this function has similar asymptotic decay properties to the half-space Green function. By using a similar approach to classical rough surface problems, we establish the uniqueness of the scattering problem. We derive the integral equation formulations using the two-layered Green function as the integral kernel and use them to prove the existence of the scattering problem. Furthermore, we propose the Nystöm method for discretizing the integral equations and establish its convergence. Finally, we perform numerical experiments to demonstrate the effectiveness of the Nystöm method., 44 pages with 3 figures

Additional file 1.

Additional file 2: Table 1. Steinhoff classification.

The COVID-19 pandemic has sparked a global interest in understanding the mechanism of transmission of bioaerosols in enclosed environments. Swift and accurate calculations of particle trajectories are crucial for predicting the diffusion of bioaerosols. The use of machine learning can expedite these calculations and predictions. However, research focusing on the use of machine learning methods for calculating bioaerosol trajectories remains scarce. A bioaerosol trajectory is a time series with long intervals and delays between different positions; certain machine learning models are well suited for handling time series data. Herein, we aimed to establish a new method we refer to as physics–machine learning (P–ML) that includes a machine learning model for calculating bioaerosol trajectories. To this end, we adopted a lightweight, single-layer long short-term memory (LSTM) model and used supervised learning with mean squared error as an evaluation metric for training. Our findings indicate that disregarding the turbulence diffusion enables us to train the LSTM model by a motion equation. Furthermore, the model accurately predicted trajectories while exhibiting some degree of transferability. However, when considering the turbulence diffusion of bioaerosol, the training data in P–ML method could not be generated using a motion equation with turbulence diffusion model (Discrete Random Walk model). To address this issue, we integrating the fluctuating velocity into the LSTM model input. Consequently, the predicted results were consistent with the motion equation. Our method exhibits considerable potential for expediting trajectory calculation and aiding in early warning and rapid design in enclosed environments. Copyright © 2023 American Association for Aerosol Research

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Additional file 4: Table 3. Short Orientation Memory Concentration Test.

Additional file 3: Table 2. Brain relaxation 4-point scale.

Verticilllium wilt of cotton is a devastating soil-borne disease, which is caused by Verticillium dahliae Kleb. Bacillus velezensis strain AL7 was isolated from cotton soil. This strain efficiently inhibited the growth of V. dahliae. But the mechanism of the biocontrol strain AL7 remains poorly understood. To understand the possible genetic determinants for biocontrol traits of this strain, we conducted phenotypic, phylogenetic and comparative genomics analysis. Phenotypic analysis showed that strain AL7 exhibited broad-spectrum antifungal activities. We determined that the whole genome sequence of B. velezensis AL7 is a single circular chromosome that is 3.89 Mb in size. The distribution of putative gene clusters that could benefit to biocontrol activities was found in the genome. Phylogenetic analysis of Bacillus strains by using single core-genome clearly placed strain AL7 into the B. velezensis. Meantime, we performed comparative analyses on four Bacillus strains and observed subtle differences in their genome sequences. In addition, comparative genomics analysis showed that the core genomes of B. velezensis are more abundant in genes relevant to secondary metabolism compared with B. subtilis strains. Single mutant in the biosynthetic genes of fengycin demonstrated the function of fengycin in the antagonistic activity of B. velezensis AL7. Here, we report a new biocontrol bacterium B. velezensis AL7 and fengycin contribute to the biocontrol efficacy of the strain. The results showed in the research further sustain the potential of B. velezensis AL7 for application in agriculture production and may be a worthy biocontrol strain for further studies.

Background: The development of environment-friendly and cost-effective palladium( Pd) based nanocomposite is of high interest for catalytic applications. Objective and Methods: In this paper, a porous Pd/two-dimensional-material (graphene oxide (GO) and reduced graphene oxide (rGO)) nanocomposite was synthesized with a green and facile method, without adding any additional reductant, surfactant and special solvent. Results: The catalytic activity of the Pd/rGO composite was investigated using the 4-nitrophenol (4-NP) reduction reaction in the presence of sodium borohydride (NaBH4). The results showed that the Pd/rGO nanocomposite not only exhibited much higher catalytic activity than the pure porous Pd catalyst but also showed a very good catalytic stability due to the less Pd aggregation and increased local 4-NP concentration arose from rGO bonding attraction. Besides, the Pd-rGO nanocomposite showed a kapp value of 0.383 min-1, which was 13 times higher than the pure Pd (0.0292 min-1), as well as a reliable 4-NP conversion rate of over 97%. Conclusion: This study may provide a route for green-design and synthesis of heterogeneous catalyst composites with lower cost and better performance.

Single-crystal metals are promising substrates for the epitaxial growth of two-dimensional (2D) materials owing to the absence of grain boundaries and distinctive symmetries. The rich arrangements of atoms on various crystal facets serve as an ideal platform for cutting-edge research on regulating the structures of the as-grown 2D materials. However, it is challenging to obtain large single-crystal metal materials, which hinders the in-depth exploration of single-crystal metal-2D material interface interactions. This review provides a critical summary of the recent progress towards achieving large-area single-crystal metals via anomalous grain growth and epitaxial deposition. Then, crucial roles of single-crystal metal substrates in the controlled growth of 2D materials are highlighted by discussing epitaxial growth of single crystals, rapid and low-temperature preparation, and wrinkle elimination. Finally, a perspective into future research on the preparation of single-crystal metals and 2D materials is provided, which is intended to inspire novel growth frontiers for 2D materials.

Paris L. section Axiparis H. Li (Melanthiaceae) is a taxonomically perplexing taxon with considerable confusion regarding species delimitation. Based on the analyses of morphology and geographic distribution of each species currently recognized in the taxon, we propose a revision scheme that reduces the number of species in P. sect. Axiparis from nine to two. To verify this taxonomic proposal, we employed a genome skimming approach to recover the plastid genomes (plastomes) and nuclear ribosomal DNA (nrDNA) regions of 51 individual plants across the nine described species of P. sect. Axiparis by sampling multiple accessions per species. The species boundaries within P. sect. Axiparis were explored using phylogenetic inference and three different sequence-based species delimitation methods (ABGD, mPTP, and SDP). The mutually reinforcing results indicate that there are two species-level taxonomic units in P. sect. Axiparis (Paris forrestii s.l. and P. vaniotii s.l.) that exhibit morphological uniqueness, non-overlapping distribution, genetic distinctiveness, and potential reproductive isolation, providing strong support to the proposed species delimitation scheme. This study confirms that previous morphology-based taxonomy overemphasized intraspecific and minor morphological differences to delineate species boundaries, therefore resulting in an overestimation of the true species diversity of P. sect. Axiparis. The findings clarify species limits and will facilitate robust taxonomic revision in P. sect. Axiparis.

Background Cotton has been increasingly harmed by the mirid bug (Lygus pratensis Linnaeus) in Xinjiang Uyghur Autonomous Region, China. Using trap plants within or around the border of the cotton may be a beneficial management strategy for this pest of cotton. Results The potential of safflower (Carthamus tinctorius Linn) as a trap plant for managing L. pratensis was evaluated in laboratory and field experiments. Y-tube olfactometer assays demonstrated that L. pratensis was highly attracted to volatiles derived from safflower. Field experiments showed that safflower plots hosted more L. pratensis (adults and nymphs) than cotton plots. Early-sown safflower had more L. pratensis than mid-sown or late-sown safflower, and was more conducive to the settlement and reproduction of L. pratensis. The density of L. pratensis on safflower trap crops in three sowing patterns was significantly higher than on adjacent cotton. The pattern of intercropping safflower trap crops was more effective at reducing densities of L. pratensis on cotton than placing safflower as 'spot' trap crops or peripheral trap crops. However, this result may also be related to the overall area of the safflower trap crops. With regular chemical control of L. pratensis on safflower trap crops, the number of cotton bolls was increased by 10.04%, while the rate of boll damage was reduced by 33.44%, compared to cotton without safflower trap crops and insecticide sprays. Conclusion Safflower shows promise as an effective trap crop for L. pratensis, and may contribute to controlling L. pratensis in cotton. This article is protected by copyright. All rights reserved.

It is of great significance to acquire the soil surface roughness accurately for the study of the interaction between tractors and soil. Based on the laser sensor, this paper proposed the non-contact measuring instrument of the soil surface roughness with the data acquiring system by using Lab-View software. By using W-M theory, three commonly used fractal dimension calculation methods are compared and analyzed.. The result showed that the Root-mean-square method has the highest accuracy and clear physical meaning, which is ideal method to calculate the soil surface roughness characteristics. When the fractal dimension is between 1.4 and 1.6, the acquired data is analysed by the Root-mean-square method to obtain the fractal features of the soil surface roughness. The experiment results indicated that the fractal dimension of the ploughed surface is 1.39, that of disc harrow surface is 1.550, and that of rolled surface is 1.46-1.54. Obviously, the fractal dimension can accurately distinguish the soil surface roughness with the different treatments. However, the fractal dimension selected from different scales showed an obvious instability during calculations. The surface roughness index combined with the two parameters can effectively represent the soil surface roughness, and the larger the surface roughness index is, the greater the surface roughness is.

It is of great importance to develop epoxy vitrimers with the combination of high performance and versatile recyclability. Herein, two imine-containing hardeners were synthesized from bio-based vanillin and petroleum-based p-hydroxy benzaldehyde. The epoxy resins cured by these two hardeners show high Tg (>120 °C), tensile strength (>60 MPa), Young’s modulus (>2500 MPa), and good solvent resistance. Owing to the incorporation of imine dynamic covalent bond, the cured epoxy resins are reprocessable and degradable. Notably, the chemical degradation products can be reused to prepare new epoxy resins, thus achieving a closed-loop recycling process. Both the reprocessed and chemically recycled epoxy resins exhibit high-percentage retention of thermal and mechanical properties. Finally, this study demonstrates that the epoxy resin cured by the vanillin-based hardener shows comparable thermal, mechanical, and recycling properties compared with the epoxy resin cured by the petroleum-based counterpart.

Additional file 2. Standardized Process and Indicator Definition.

Achieving realistic, vivid, and human-like synthesized conversational gestures conditioned on multi-modal data is still an unsolved problem due to the lack of available datasets, models and standard evaluation metrics. To address this, we build Body-Expression-Audio-Text dataset, BEAT, which has i) 76 hours, high-quality, multi-modal data captured from 30 speakers talking with eight different emotions and in four different languages, ii) 32 millions frame-level emotion and semantic relevance annotations. Our statistical analysis on BEAT demonstrates the correlation of conversational gestures with facial expressions, emotions, and semantics, in addition to the known correlation with audio, text, and speaker identity. Based on this observation, we propose a baseline model, Cascaded Motion Network (CaMN), which consists of above six modalities modeled in a cascaded architecture for gesture synthesis. To evaluate the semantic relevancy, we introduce a metric, Semantic Relevance Gesture Recall (SRGR). Qualitative and quantitative experiments demonstrate metrics' validness, ground truth data quality, and baseline's state-of-the-art performance. To the best of our knowledge, BEAT is the largest motion capture dataset for investigating human gestures, which may contribute to a number of different research fields, including controllable gesture synthesis, cross-modality analysis, and emotional gesture recognition. The data, code and model are available on https://pantomatrix.github.io/BEAT/., Comment: 28 pages, 15 figures, Accepted by ECCV2022

Additional file 1. SPIRIT 2013 Checklist.

Subduction of oceanic lithosphere is widely considered as the primary cause of mantle heterogeneity as reflected by the chemical variation of ocean island basalts. However, the fate of deeply subducted oceanic lithosphere (i.e., remaining intact, getting segmented or completely destroyed and intermixed with ambient mantle) is still largely unknown. Based on trace element and radiogenic isotope systematics, it has been suggested that the geochemical difference of shield and post-erosional stage lavas of the volcanic Madeira archipelago reflects recycling of different portions of subducted lithosphere (e.g., Geldmacher and Hoernle, 2000, EPSL 183; Gurenko et al. 2013, Lithos 170-171). Accordingly, the geochemical composition of the shield stage magmas reflects altered upper oceanic crust, while the isotopically less enriched post-erosional magmas preferentially stem from less-modified, lower crustal/lithospheric mantle portions of the recycled slab. New, high precision potassium (δ41K of -0.75‰ to -0.50‰) and oxygen (δ18O of 4.90‰ to 5.21‰ in olivine phenocrysts) isotope data from Madeira lavas support this model. Subduction dehydration can cause large K isotope fractionation in the upper, seawater-altered parts of oceanic crust resulting in lighter K isotopes (lower δ41K) in ocean island basalts containing such material. The measured δ41K represents the lowest range among oceanic basalts published so far and overlaps with obducted eclogite, indicating the involvement of dehydrated oceanic crust. The correlation of light K with light O and enriched radiogenic isotope ratios supports the model that Madeira’s magma source contains different portions of subducted oceanic crust, which were preserved over millions of years without significant intermixing.

Additional file 1.

Additional file 1: Supplemental Figure 1. Comparison of Baseline cytokines levels in the aqueous humor among 3 groups. Supplemental Figure 2. Comparison of cytokine levels in the aqueous humor at the beginning of PPV between group I and II. Supplemental Figure 3. Comparison of cytokine levels in the aqueous humor at the beginning of PPV between IOB and INB group.

The roughness of the interlayer concrete, which is an important index for the construction of dams, affects the mechanical properties of the interface between new and old concrete. The traditional monitoring method cannot satisfy field measurements. Therefore, this paper proposes a concrete surface roughness measurement method based on 3D laser scanning technology and implements 3D point cloud calculations. Two layers of specimens with same concrete mix proportion were poured 28 days apart, and a splitting tensile strength test of the superimposed specimen was carried out. Four groups of experiments (MR-S, MR-N, MR-15, and MR-35) tested the interlaminar tensile splitting strength of nine 150 mm cubic specimens on the 3rd, 7th, 14th, and 28th days, respectively. Filling volume, mean amplitude, surface area expansion rate, normal angle std. dev., and curvature std. dev. were measured in the study. The results showed that as the surface roughness of the concrete increased, as did the flushing pressure. The splitting strength of the concrete interface after it solidified increased with age. At 28 days, the splitting strength of MR-15 was higher than that of MR-35. The mean amplitude and the normal angle std. dev. of the rough surface could replace the traditional filling volume index. The new 3D point cloud calculation method for calculating concrete surface roughness was proven by experiments to have good performance.

To ascertain the prevalence of contralateral patent processus vaginalis (CPPV) in life and the significance of the prevalence trends for treatment. We performed a retrospective review of all inguinal hernias (IHs) that underwent repair in our hospital from 2014 to 2018. We analyzed the frequency of occurrence and treatment in boys. We assessed and compared the history, initial sides of hernia, CPPV and prognoses in different age groups. We assessed all IH cases repaired in our hospital and selected male patients of a variety of ages, including boys and men. Recurrent cases were not enrolled. A total of 3243 cases were enrolled: 2489 [right-sided IH 1411 (56.69%) vs. left-sided IH 975 (39.17%), bilateral IH 103 (4.14%)] in children and 754 [right-sided IH 485 (64.32%) vs. left-sided IH 236 (31.30%), bilateral IH 33 (4.38%)] in adults. A total of 1124 CPPVs were identified in children with unilateral IH (2386), and 12 were identified in adults (267) (p 0.05). The incidence of IH in boys was significantly higher than that in men. The number of incident cases declines rapidly with age in boys. The processus vaginalis is normally obliterated and involuted but may instead remain patent for a long period before closure; routine exploration on the contralateral side may eliminate the possibility of spontaneous PPV closure.

Conventional reduction treatment methods for nickel slag show drawbacks such as high energy cost, heavy material burden or secondary pollution. Thus, a novel environmentally friendly reduction treatment method for high-silicon wastes, especially nickel slag, is proposed in this paper. The main characteristic is to lower the alkali–ore ratio (mass ratio of NaOH to ore) through introducing a high-speed premixing procedure before roasting. Optimal process parameters have been found experimentally, i.e., a roasting temperature of 823 K, alkali–ore ratio of 1.6:1, and roasting time of 30 min. The desilication ratio reached to 91.3 wt.%. Compared with previous NaOH roasting processes with stirring, the NaOH consumption is down by 60%, which greatly reduces the material burden. Through carbonation decomposition of the Na2SiO3 solution generated in the NaOH roasting, amorphous silica is recycled as the final product. The proposed method is expected to be a promising method for industrial reduction treatment of nickel slag.

Deep-water fish cage floating collar also referred to as float, bears a load in the form of waves, fishing nets, and moorings, in which the longitudinal wave force is the main type of loading. The long-term continuous effects caused by wave force could cause reduction in strength, or vibration failure in the floating collar. In this study, the peak responses of a single-point mooring (SPM) cage floating collar, due to either static or vibration loadings, were calculated by the finite element method (FEM) based on an elastic model. In this model, the float exhibited macro-plastic deformation when the stress of 26.1 MPa, generated under 100 kN load, was greater than the yield limit (25 MPa). With the increase in order modes from 1 to 18 (1.2–7.9 Hz), the stress increased. Moreover, the harmonic stress corresponding to 8 and 0.1 Hz was clearly higher than that for 0 Hz under 100 kN loads, due to structural resonance. The range of stress values due to the random vibration was 16.0–63.7 MPa, when the angular velocities (k) were in the range of 0.01–16 rad s―1. Moreover, the transient response (34.4 MPa) was maximum when the angular velocity was 10 rad s―1 (range 1–100 rad s―1). The reliability rate of the entire body was 53.1% and 97.0% after 108 loading cycles for 100 kN and 10 kN loads, respectively. Furthermore, the fatigue modes of the key components were determined from the outer triangular tops and inner hexagonal intersections. In short, static analysis, vibration analysis, and fatigue analysis of FEM could be used as reliable ways to evaluate structural strength and failure for floating system. Finally, the floating parts could be strengthened with partially double pipes or optimized by increasing the stiffness, and appropriate damping could be widely used.

The SC200 proton therapy facility is consisting of a superconducting cyclotron, a gantry treatment room and a fixed beam room. The proton beams are transported mainly with beam transport devices, such as dipole magnets, quadrupole magnets, and corrector magnets which lie on the beam transport line layout of which is based on the beam optics design. A series of dipole, quadrupole, and corrector magnets ultimately make high-quality transmission of proton beams possible. Dipole magnets are mainly for beams deflection, quadrupole magnets are for beam focusing, and corrector magnets for orbit correction of beams. This paper shows the design of such magnets for the beam transport line. Besides, main parameters of magnets are presented and magnetic analysis work is also illustrated in this paper. The magnetic fields of dipole and quadrupole magnets are measured by hall mapping system and rotary coil measuring system. The results show that the measuring results are a little worse than the simulation results. However, both methods can meet the design requirement and the basic trend is similar to each other.

Twisted bilayer graphene (tBLG) has recently attracted growing interest due to its unique twist-angle-dependent electronic properties. The preparation of high-quality large-area bilayer graphene with rich rotation angles would be important for the investigation of angle-dependent physics and applications, which, however, is still challenging. Here, we demonstrate a chemical vapor deposition (CVD) approach for growing high-quality tBLG using a hetero-site nucleation strategy, which enables the nucleation of the second layer at a different site from that of the first layer. The fraction of tBLGs in bilayer graphene domains with twist angles ranging from 0° to 30° was found to be improved to 88%, which is significantly higher than those reported previously. The hetero-site nucleation behavior was carefully investigated using an isotope-labeling technique. Furthermore, the clear Moiré patterns and ultrahigh room-temperature carrier mobility of 68,000 cm2 V−1 s−1 confirmed the high crystalline quality of our tBLG. Our study opens an avenue for the controllable growth of tBLGs for both fundamental research and practical applications., The synthesis of twisted bilayer graphene with controllable angles is challenging. Here, the authors devise a chemical vapor deposition approach using a hetero-site nucleation strategy that affords twist angles ranging from 0° to 30°.

Higher magnetic fields are always favoured in the magnetoplasmadynamic thruster (MPDT) due to its superior control of the plasma profile and acceleration process. This paper introduces the world's first integrated study on the 150 kW level AF-MPDT equipped with a superconductive coil. A completely new way of using superconducting magnet technology to confine plasma with high energy and extremely high temperatures is proposed. Using the PIC method of microscopic particle simulation, the plasma magnetic nozzle effect and performance of the MPDT under different magnetic-field conditions were studied. The integrated experiment used demonstrated that, in conjunction with the superconducting coil, greater homogeneity and a stronger magnetic field not only caused more even cathode ablation and improved its lifespan but also improved the performance of the MPDT (maximum thrust was 4 N at 150 kW, 0.56 T). Maximum thrust efficiency reached 76.6% and the specific impulse reached 5714 s.

Speech production is a dynamic procedure, which involved multi human organs including the tongue, jaw and lips. Modeling the dynamics of the vocal tract deformation is a fundamental problem to understand the speech, which is the most common way for human daily communication. Researchers employ several sensory streams to describe the process simultaneously, which are incontrovertibly statistically related to other streams. In this paper, we address the following question: given an observable image sequences of lips, can we picture the corresponding tongue motion. We formulated this problem as the self-supervised learning problem, and employ the two-stream convolutional network and long-short memory network for the learning task, with the attention mechanism. We evaluate the performance of the proposed method by leveraging the unlabeled lip videos to predict an upcoming ultrasound tongue image sequence. The results show that our model is able to generate images that close to the real ultrasound tongue images, and results in the matching between two imaging modalities., Comment: Accepted in KDD Workshop (BIOKDD 2021)

The rich and complex arrangements of metal atoms in high-index metal facets afford appealing physical and chemical properties, which attracts extensive research interest in material science for the applications in catalysis and surface chemistry. However, it is still a challenge to prepare large-area high-index single crystals in a controllable and cost-efficient manner. Herein, entire commercially available decimeter-sized polycrystalline Cu foils are successfully transformed into single crystals with a series of high-index facets, relying on a strain-engineered anomalous grain growth technique. The introduction of a moderate thermal-contact stress upon the Cu foil during the annealing leads to the formation of high-index grains dominated by the thermal strain of the Cu foils, rather than the (111) surface driven by the surface energy. Besides, the designed static gradient of the temperature enables the as-formed high-index grain seed to expand throughout the entire Cu foil. The as-received high-index Cu foils can serve as the templates for producing high-index single-crystal Cu-based alloys. This work provides an appealing material basis for the epitaxial growth of 2D materials, and the applications that require the unique surface structures of high-index metal foils and their alloys.

Bacillus velezensis AL7, isolated from cotton soil, had strong antagonistic activity to Verticillium dahlia Kleb. The AL7 genome consisted of one chromosome with 3,894,709 bp (46.64% G+C content). Genome annotation predicted 3,706 protein-coding genes, 86 tRNAs, and 27 rRNAs. We sequenced and annotated the complete AL7 genome to help us better understand use of this strain.

Recent advancements in medical entity linking have been applied in the area of scientific literature and social media data. However, with the adoption of telemedicine and conversational agents such as Alexa in healthcare settings, medical name inference has become an important task. Medication name inference is the task of mapping user friendly medication names from a free-form text to a concept in a normalized medication list. This is challenging due to the differences in the use of medical terminology from health care professionals and user conversations coming from the lay public. We begin with mapping descriptive medication phrases (DMP) to standard medication names (SMN). Given the prescriptions of each patient, we want to provide them with the flexibility of referring to the medication in their preferred ways. We approach this as a ranking problem which maps SMN to DMP by ordering the list of medications in the patient's prescription list obtained from pharmacies. Furthermore, we leveraged the output of intermediate layers and performed medication clustering. We present the Medication Inference Model (MIM) achieving state-of-the-art results. By incorporating medical entities based attention, we have obtained further improvement for ranking models.

In this study, a numerical model was established to simulate the dynamic behavior of a floating net cage in waves and current, based on the finite element method. To validate the numerical model, we considered a case based on the motions of the net cage under regular waves and current, where we calculated and compared the simulated results. The comparison of the results indicated good agreement. We calculated the dynamic deformation of the floating collar of the net cage under regular/irregular waves and current, and we analyzed the effects of the net, strong waves and current, and the length of the mooring line on the cage collar deformation. The results indicated that the deformation of the floating collar with a net was much greater than that without a net. The collar deformation became larger as the wave height or current velocity increased. Therefore, in order to reduce the risk of local collar failure due to plastic deformation, adding a casing pipe in the position of the mooring line connection point on the floating collar could greatly enhance the bearing capacity of the cage collar under severe sea conditions. In addition, increasing the length of the mooring line would help to decrease the mooring line tension and further reduce deformation of the cage collar.

The mirid bug Lygus pratensis is an important pest of cotton, and is primarily managed through insecticide application. In this study, conducted in Xinjiang (China), we assessed the relative attractiveness of sunflower (Helianthus annuus) to L. pratensis adults in local cotton plots from 2015-2016 and quantified the associated contribution of inter-planted sunflower strips to suppress field-level L. pratensis populations from 2016-2017. Field-plot trials showed that among six combinations of two sunflower varieties (XKZ6 and SH363) and three planting dates (early-, middle- and late-planted), adult abundance of L. pratensis was highest on early-planted XKZ6 and attained 3.7-5.8 times higher levels than in neighboring cotton plots. In commercial cotton fields, the combined deployment of sunflower strips at field edges and the periodic application of insecticides directed to those strips was found to (1) reduce the mean abundance of L. pratensis population on cotton by 41.9-44.0%, (2) lower the rate of cotton leaf damage by 27.3-30.6% and boll damage by 44.8-46.0%, and (3) increase the number of mature bolls by 7.5%-8.0%. Our work emphasizes how sunflower can be an effective trap crop for L. pratensis and that the establishment of sunflower strips could contribute to its effective and environmentally-sound management in cotton crops.

During the pneumatic conveying process of automatic feeding systems for deep-water off-shore cage culture, blockages of the pipeline and damage to feed pellets can easily occur. To solve these issues, a numerical simulation of the gas-solid two-phase flow of feed pellets in a pipeline was carried out. Based on gas-solid two-phase flow theory, both a computational fluid dynamics (CFD) model and discrete element model were established. Furthermore, solutions of a coupled CFD-DEM simulation were used to analyze the motion of feed pellets within the pneumatic conveying pipeline and changes in the distribution of pellets at various locations from the initial state to steady-state motion were determined. The pressure in the pipeline at different positions is analyzed and compared, and the pressure drop from the inlet of the pipeline to the stable state of particle movement is obtained. The simulation results provide an important basis for the clogging damage mechanism of feed particles and the optimal design of feeding system equipment.

Shapelet is a discriminative subsequence of time series. An advanced shapelet-based method is to embed shapelet into accurate and fast random forest. However, it shows several limitations. First, random shapelet forest requires a large training cost for split threshold searching. Second, a single shapelet provides limited information for only one branch of the decision tree, resulting in insufficient accuracy and interpretability. Third, randomized ensemble causes interpretability declining. For that, this paper presents Random Pairwise Shapelets Forest (RPSF). RPSF combines a pair of shapelets from different classes to construct random forest. It omits threshold searching to be more efficient, includes more information for each node of the forest to be more effective. Moreover, a discriminability metric, Decomposed Mean Decrease Impurity (DMDI), is proposed to identify influential region for every class. Extensive experiments show RPSF improves the accuracy and training speed of shapelet-based forest. Case studies demonstrate the interpretability of our method., Comment: There is some misunderstanding between authors when this manuscript is submitted. Some of authors disagree to submit this manuscript. So we decide to withdraw the article

The accuracy of power measurement affects the economic benefits and operating costs of power supply companies, and even affects corporate decision-making. Analyzing the causes of errors in measurement data and making improvements to reduce errors is of great significance to both power companies and users. The article analyzes the causes of power measurement errors, and proposes improvement measures to reduce the errors.

The dynamic behavior of a fish cage collar in waves was investigated using a numerical model based on the finite element method. The floating collar and mooring system were divided into a series of line segments modeled by straight massless model segments with a node at each end. To verify the validity of the numerical model, research data from other authors were cited and compared with the simulated results, the comparison of results showed a good agreement. The numerical model was then applied to a dynamic simulation of a floating cage collar in waves to analyze its elastic deformation and mooring line tension. The simulated results indicated that the greatest deformation of the collar taken place in the position of the mooring line connection point when incident waves were in the same direction. An increase in the length of mooring line would help to decrease the mooring line tension of the collar. Furthermore, the effects of collar dimension, including collar circumference, pipe diameter in cross-section, and pipe thickness, on the dynamic behavior of the floating collar were discussed. The results of this study provided a better understanding of the dynamic behavior of the fish cage collar.

A layered aluminoborophosphate(LABP-DDA) was hydrothermally synthesized using dodecylamine as a structure-directing agent, and was added into polyamide 66(PA66) to obtain nanocomposites, PA66/LABP-DDA, via melt intercalation method. The characterization results of transmission electron microscopy(TEM) and small angle X-ray scattering (SAXS) indicate that LABP-DDA has been successfully exfoliated into nano-layers of PA66 matrix. The unstable γ phase of PA66 was found in the composites with the help of X-ray diffraction(XRD) and differential scanning calorimetry(DSC). The heterogeneous nucleation effect of LABP-DDA resulted in an increasement of about 10 °C in melting temperature and an increasement of about 7% in crystallinity when compared with those of neat PA66. The introduction of LABP-DDA did not significantly affect the toughness and strength of PA66. The results of flammability test indicate that LABP-DDA possesses positive synergistic flame retarding effect in the presence of melamine polyphosphate(MPP) and the 77%PA66/(23–x)%MPP/x%LABP-DDA(x=1, 2) samples in thickness of 1.6 mm reached from Fail to V-1 rating based on UL94, compared with 77%PA66/23%MPP.

Affected by factors such as the city's functional orientation and tourism consumption, the spatial layout of the catering industry in a tourism city has its own distinctive characteristics. The spatial distribution characteristics of the catering industry and the factors impacting it (from the perspectives of transportation, tourism resources and population) in the main city area of Lhasa, Tibet were analysed through point of interest data mining, average nearest neighbour analysis, a standard deviational ellipse, kernel density estimation, and buffer analysis in ArcGIS software. As a result, the spatial distribution pattern showed catering providers are mainly aggregated in the vicinity of areas with either developed transportation or rich tourism resources. The resident population has an important but inconclusive influence on the distribution, while the distribution of its concentration is highly consistent with that of the instant population. Considering the spatial structure, functional orientation, and tourism development of the area, measures are proposed for optimizing the spatial layout of the catering industry in this tourism-heavy plateau city.

Due to the typhoon impacts, aquaculture net cages may be exposed to the risk of structural failure as a far-reaching aquaculture equipment. In addition, the fatigue problem of key components due to long-term marine alternating loads can not be ignored. The method is developed independently on processing samples of cage for testing its performance parameters, among which the fatigue Wohler curve is S = -1.022ln (N) + 22.201. By adapting the following methods: Mechanical test, Equivalent load finite element simulation and Full field finite element simulation respectively is verified each other, and the error is less than 5%. The key nodes of the stress concentration of the floating frame are mainly the welding point, the mooring point and the edge area of the I-beam frame at both sides. The damage of the cage which caused by tensile and bending loads should be considered at the same time. And the tensile strength 22.12 MPa and the bending strength 30.58 MPa could be taken as the evaluation standard for the elastic to plastic deformation. Structural fracture occurs when the elongation at break exceeds 340.18%. The fatigue of the cage is mainly because the stress is much greater than the fatigue limit 3.38 MPa. The material model test combined with structural mechanics simulation provides the basis for guiding the structural optimization design of the cage.

Lithium-ion batteries have become critical components to industries as automotive, military, space, medical and consumer electronics. Electrochemical impedance spectroscopy (EIS) is a well-known technique employed on various electrochemical cells including lithium-ion cells, which is practical in estimating battery state of health, as ohmic resistance, formation of solid electrolyte interphase (SEI) film, activation on solid and liquid interface and diffusion process in the battery can be reflected in the Nyquist curve of EIS. However, the long acquisition time of standard EIS makes it unsuitable for rapid on-line impedance measurements. This paper presents a time domain measuring technique based on Fast Fourier Transformation (FFT). Time domain excitation, such as a multi-sine excitation, is applied to the measured system. The excitation and response of the system are acquired simultaneously. Through FFT, acquired signals are transformed from time domain to frequency domain, thus the impedance in frequency domain is calculated. The technique is verified on both lithium-ion battery equivalent circuit and real lithium-ion battery. The resulting impedance data show that proposed technique has good concordance with standard EIS and greatly reduceds the acquisition time compared with standard EIS.

Students' dropout rate is a key metric in online and open distance learning courses. We propose a time-series classification method to construct data based on students' behaviour and activities on a number of online distance learning modules. Further, we propose a dropout prediction model based on the time series forest (TSF) classification algorithm. The proposed predictive model is based on interaction data and is independent of learning objectives and subject domains. The model enables prediction of dropout rates without the requirement for pedagogical experts. Results show that the prediction accuracy on two selected datasets increases as the portion of data used in the model grows. However, a reasonable prediction accuracy of 0.84 is possible with only 5% of the dataset processed. As a result, early prediction can help instructors design interventions to encourage course completion before a student falls too far behind.

As one of the most popular and successful methods in industrial applications, model predictive control (MPC) has attracted increasing interest in the past two decades. However, one of open issues in this research filed is how to solve the constrained nonlinear optimization problems in MPC. From the perspective of evolutionary algorithm, this paper presents a novel population extremal optimization (PEO) based modified constrained generalized predictive control (CGPC) method called CGPC-PEO. The key idea behind the proposed CGPC-PEO is using PEO for rolling optimization to minimize the weighted objective function subjecting to a set of constraints. Its superiority to other evolutionary algorithms such as genetic algorithm and particle swarm optimization based CGPC is demonstrated by the simulation results on an industrial process plant.

Design of an effective and efficient fractional order PID (FOPID) controller for an industrial control system to obtain high-quality performances is of great theoretical and practical significance. This paper presents a novel real-coded extremal optimization algorithm with multi-non-uniform mutation called RCEO-FOPID to design FOPID controllers. The key idea behind the proposed algorithm is the population-based iterated optimization, which consists of generation of a real-coded random initial population by encoding the parameters of a FOPID controller into a set of real values, evaluation of the individual fitness by using a novel and reasonable control performance index, generation of a new population based on multi-non-uniform mutation and updating the population by accepting the new population unconditionally. The proposed RCEO algorithm for the design of FOPID controller is relatively simpler than these reported popular evolutionary algorithms, e.g., genetic algorithm (GA), particle swarm optimization (PSO), chaotic anti swarm (CAS) due to its fewer adjustable parameters and only with selection and mutation operators. Furthermore, extensive simulation results on automatic voltage regulator system and multivariable control system have shown that the proposed RCEO-based FOPID controller is superior to other reported evolutionary algorithms-based FOPID and PID controllers in terms of accuracy and robustness. DOI: http://dx.doi.org/10.5755/j01.itc.45.4.13310