Abstract:This paper deals with the existence, multiplicity and nonexistence of positive ω-periodic solutions for a class of differential equations involving parameter and multiple delays. Some results are obtained by using the Krasnoselskii fixed point theorem on cones.

Abstract:In this paper, the existence of solutions for a class of third-order ordinary differential equation with periodic boundary value is considered. By applying the Fourier~analysis method and Leray-Schauder fixed point theorem, the existence and uniqueness of the solutions of the equation are obtained under the nonlinear term satisfies the proper growth conditions.

Abstract:The existence of positive periodic solutions of a class of second-order differential equation is obtained by using the Schauder's fixed point theorem. The main results generalize some recent results.

Abstract:We use the blended force-based atomistic-continuum coupling (BQCF) method to solve a Frenkel-Kontorova model and consider its adaptivity problem. We give a posteriori error estimator based on the residual. Then, by using this estimator, we construct a model adaptive algorithm, which adaptively determines the domain decomposition of an atomistic system and characterize the partition of the atomistic domain and the continuous domain. Numerical experiments illustrate the validity of the estimator and algorithm.

Abstract:In this paper, numerical solution of the initial-boundary value problem for Benjamin-Bona-Mahony equation under homogeneous boundary is considered. A linearized three-level difference scheme is introduced. The difference scheme simulates a conservative quantity of the problem. Furthermore, convergence and stability of the difference scheme are proved by discrete energy method. Numerical experiments verify the reliability of this method.

Abstract:A Robust V-cycle multigrid method is constructed for the linear system arising from the bilinear finite element discretization of anisotropic linear elasticity equations. By using the Xu-Zikatanov (XZ) identity, quasi-optimal convergence of the method is established in the sense that the multigrid method is independent of the parameterε and dependent on h in a very weakly way. Since the 'regularity assumption' is not used in the analysis, the results can be extended to domains consisting of rectangles. Numerical experiments confirm the theoretical results.

Abstract:In this paper,we study the global structure of a class of discrete periodic boundary value problem involving φ-Laplacian operator.The main results extend and improve some known results.

Abstract:Heart sound signal can reflect the activity of the human heart valve, and the heart sound classification can distinguish the pathological information of different heart sounds, which is of great significance for clinical diagnosis of different heart diseases. Heart sound segmentation is the premise of heart sound classification. The heart sound segmentation can locate the first heart sound (S1) and the second heart sound (S2) in the heart sound, and provide a positioning reference for heart sound feature parameter extraction and heart sound classification. For this reason, a new adaptive threshold selection heart sound segmentation algorithm is proposed in this paper. This method first uses the wavelet transform default threshold method to denoise the heart sound signal; then uses the normalized Shannon energy to extract a smoother heart sound envelope; then performs effective peak detection on the envelope to determine the initial large threshold TH1, and the final stable double threshold is obtained by an iterative method; finally, heart sound segmentation and the segmentation result analysis are performed. For partial abnormal heart sounds segmentation results, such as the segmentation result of heart sound splitting, the heart sound segment is merged or removed by using the characteristics of heart sound time domain and energy, which ensures the accuracy of the segmentation result. The experimental results show that the segmentation accuracy of normal and abnormal heart sounds is 97.24% and 91.83%, and the overall segmentation accuracy is 95.56%, which is higher than the traditional threshold selection segmentation method.

Abstract:In order to solve the problem of automatic guided vehicle (AGV) path planning in green remanufacturing system, an adaptive algorithm for global path optimization of AGV based on particle swarm optimization (PSO) is proposed. This method not only integrates the advantages of genetic algorithm (GA) and particle swarm optimization (PSO), but also improves the slow search speed of traditional fusion algorithm in the early iteration stage. In order to improve the convergence accuracy of the algorithm in the later iteration stage, a dual crossover mutation strategy is proposed. The improved PSO-GA fusion algorithm has stronger search ability, faster evolution speed and higher convergence precision than the traditional PSO-GA fusion algorithm. In order to verify the superiority of the improved algorithm, the grid method is used to simulate the running environment of the auto-guided transport vehicle, and the four algorithms of standard particle swarm optimization, genetic algorithm, traditional PSO-GA fusion and improved PSO-GA fusion are solved by MATLAB. The experimental results show that the improved PSO-GA algorithm is feasible and effective.

Abstract:Considering the interaction between the nitrogen molecular vibration and rotation as well as the anharmonicity of vibration, together with the precise spectral constants of nitrogen molecules, which allows us to establish the exact partition function and the thermodynamic functions of nitrogen molecules by using the vibration rotor and the non-harmonic oscillator approximation. In the range of 100 to 6000 K, the author made a groundbreaking effort to systematically probe into the contribution of the translation, vibration and rotation of nitrogen molecules to the molar internal energy, relative molar enthalpy, isobaric molar heat capacity, standard molar entropy and standard molar Gibbs free energy. The calculated results agree well with the experiment and theory. It indicates that the calculated thermodynamic parameters of the nitrogen are accurate and credible in the range of 100~6000 K, and also provides a method for calculating the thermodynamic parameters accurately.

Abstract:We use a two temperature molecular dynamics model considering electronic pressure gradient to investigate the ablation dynamics process of CuZr amorphous alloy nanofilm irradiated by femtosecond laser, in which the fluence is selected from 0.08 to 0.16 and the duration of laser is 100fs. The results indicate that , at low laser fluence, the electronic pressure gradient has a little impact on the structural damage process of the target material. At high laser fluence, the electronic pressure gradient has a significant influence on the evolution of the electron temperature and the lattice temperature field of the internal target material. Under the effect of electronic pressure gradient, the presence of rapid nonthermal ablation process of the structure of CuZr amorphous alloy nanofilm is on the time scale of picosecond, and with the increasing fluence, this ultrafast nonthermal ablation process can be advanced on the timescale.

Abstract:We report the experimental measurements of dynamic quantum transport in a quantum point contact structure. Both the real and the imaginary parts of the admittance show significant steps, and the imaginary parts of the admittance reflect the inductive response of the time-dependent oscillating voltage. However, the plateaus around zero magnetic field are not perfect flat due to backscattering. The external magnetic field can effectively suppress backscattering and improve the quantity of the quantized steps. The flatter plateaus are observed when the magnetic field extends to 0.3 T. Continuing to increase the magnetic field, the magnetic depletion effect will play role, and thus the sub-band spacing of the zero magnetic field can be estimated.

Abstract:Clathrates are extraordinary thermoelectric materials due to their low thermal conductivity. However, it is generally assumed that the atoms captured in the cages, so-called the guests, act as “rattlers” inducing disordered lattice dynamics and unusual thermal properties. Here, the isotope Ge-76 has an evident influence on the phonons and the heat capacity of Ba8Ga16Ge30 (BGG) by using ab initio lattice dynamics calculations. The results verify the intense coupling between the guest and host lattice which contributesto the anomalous specific heat. This finding paves the way for understanding the microscopic mechanism of clathrates and designing the thermoelectric materials with high performance.

Abstract:Detection efficiency of gamma rays is an important factor to affect the measurement accuracy of radioactivity. There are two methods to acquire detection efficiency currently, the standard sample method and Monte Carlo method. Both methods have their own problems which would result in system error of detection efficiency. A new method based on the above two methods is proposed. In this method, the detection efficiency ratio of the tested sample to the standard sample was calculated through Monte Carlo method, multiplied by the detection efficiency of the standard sample obtained from the experiment, and then the detection efficiency of sample tested is acquired. The correctness of the new method was verified by Monte Carlo software and proved that this new method could avoid the system errors from the standard sample method entirely and Monte Carlo method in most cases.

Abstract:China dark matter experiment (CDEX) intends to use liquid argon detector as an anti-coincidence detector for high-purity germanium detectors. The photomultiplier tube used in the liquid argon detector needs to be able to work stably for a long time under the liquid argon temperature (87.3 K). Before using the PMT, we need to know its performance under low temperature. In this paper, the ETL 9357FLA photomultiplier tube was tested at room temperature and low temperature respectively, and important experimental results of single photoelectron response, dark count rate and stability in low temperature environment were obtained. According to the detailed comparison and analysis of PMT performance in the room temperature and low temperature environment, we confirmed that this type of PMT can work in low temperature environment.

Abstract:The effects of kinds and concentrations of acid and treatment time on the transformation of lithium titanate (Li2TiO3) have been studied in detail. The results show that it is easier for Li2TiO3 to turn into anatase and rutile TiO2 in hydrochloric acid medium when the same acidity of sulfuric acid and hydrochloric acid are used to treat Li2TiO3 for modification. The change of Li2TiO3 into anatase and rutile TiO2 becomes easier for the higher the concentration of sulfuric acid. In addition, more Li2TiO3 can be converted to anatase and rutile TiO2 under the longer the time of acid-treated. The sulfate radical coordinates with titanium dioxide by chelating double teeth, which is helpful for stabilizing the anatase crystalline phase. The electrophilic H+ and the high electronegative Cl- affect the Ti-O bond, resulting in the destruction of the Ti-O bond in TiO6 octahedrons, and thus promoting the structural rearrangement of anatase to rutile TiO2. From the view point that the stable structure and crystal phase of lithium ion sieve ensuring extraction lithium ion efficiently and circularly, sulfuric acid is more suitable as eluent for the preparation of lithium ion sieve than hydrochloric acid, and sulfuric acid with a low concentration is a better choice.

Abstract:In order to establish the QSAR model to predict activities of imidazole ALK5 inhibitors, the relationship between molecular structures and the activities (pIC50) of 61 kinds of imidazole ALK5 inhibitors was analyzed. Moreover, the molecule shape indices, electrical topological state indices and electric distance vectors of these compounds were calculated. The molecule shape indices K1 and K3, the electrical topological state indices E19, E21 and E24, as well as electric distance vectors M26, M30 and M56, were optimized and screened. The eight parameters were used as input layer neuron variables of neural network and the activity data pIC50 was used as output layer neuron variable, the 8:4:1 neural network structure was adopted and the artificial neural network method was used to establish a more satisfying QSAR prediction model. The total correlation coefficient r is 0.956. The predicted values of pIC50 and experimental values are very close, and the mean relative error is 0.85%. The results showed that the neural network model has strong stability and good predictive ability. It can provide guidance for the synthesis of new anticancer drugs with high activity.

Abstract:II, III and IV groups were widely investigated to synthesize guest-host thermoelectric compounds in order to obtain high optimal ZT value materials. While a novel layered structure was less reported for Sr-Al-Ge system. In this study, SrAl2Ge2 single crystal was grown by aluminum flux at 1150℃ and characterized by powder X-ray methods. It is isotropic and crystallize in the CaAl2Si2-type structure through the Rietveld refinement method (space group P3-m1) with the lattice constants a=b=4.2339(1) Å, c=7.4809(0) Å. Temperature-depended resistivity on single crystals along the c-axis shows p-type semiconducting behavior. Heat capacity (Cp) was measured in 2-300 K and low temperature Cp was consistent with data calculated by using Debye model. This work opens up a novel avenue for seeking and designing environment-friendly and high-performance thermoelectric materials.

Abstract:Recent works have shown that sulfur can be considered as useful growth-promoter for the fabrication of carbon nanostructures with different types of morphologies, such as: Y-junctions, urchin-like structures, single wall CNTs (SWCNTs) strands, double-walled CNTs films, amorphous CNTs, and others. In addition, it has been shown that the encapsulation of high pressure Fe7C3 and Fe5C2 can be achieved in conditions involving the use of small concentrations of sulfur and very low vapour flow rates. However further investigations are necessary in order to understand not only the conditions of encapsulation of such high pressure phases inside CNTs but also the parameters necessary for their morphological control and fabrication in the form of continuous vertically aligned films, which could be of interest for magnetic data recording applications. In the attempt to address these missing points in this work we performed detailed investigations on the encapsulation of such unusual iron carbide phases inside CNTs by using sulfur/ferrocene mixtures as growth promoter and catalyst/hydrocarbon sources and smoot Si/SiO2 substrates as localized growth area in presence of laminar Ar-flow. The obtained CNTs structures were characterized by using SEM, TEM, HRTEM, XRD and VSM techniques. The results indicate the possible presence of junctions between the carbide phases encapsulated inside the CNTs, namely Fe5C2 and Fe7C3 which could be of interest for data recording applications.

Abstract:In order to further explore the Actinidia fruit development and fruit commercial value, the fruit of a wild A. eriantha (found and cultivated in Sichuan, China) was used as the material to measure the dynamic changes of Physicochemical properties by combining field sampling and laboratory measurement.The results showed that flesh weight, vertical and horizontal diameter, as well as dry matter (DM) accumulation showed a sigmoidal increase trend during the fruit development. The period of starch accumulation was short, fructose and glucose concentration rose sharply after 105 DAA, and a small amount of sucrose and maltose were formed in the fruit physiology mature stages. The concentration of malic acid and citric acid showed an overall upward trend, while quinic acid remained relatively constant before 90 DAA, and rapidly decreased to the minimum at 105 DAA, and then remained relatively stable after words. The VC concentration was high and showed a decreasing trend. The A. eriantha fruit had excellent horticultural characters, and its fruit has a high content of organic acid, especially VC, which was a natural vitamin pool.

Abstract:The purpose of this research is to study the chemical constituents in the leaves of Heilongjiang han hemp and establish a method for the determination of cannabidiol (CBD). The ethyl acetate extract of hemp leaf was separated and purified by silica gel column chromatography, C18 reverse phase medium voltage column and semi preparative chromatography to obtain 5 monomer compounds. And the structure of these compounds was determined by nuclear magnetic (NMR) analysis. They were cannabidiol (CBD), cannabigerol (CBG), cannabinol (CBN), Δ9-Tetrahydrocannabinolic acid (Δ9-THCA) and cannabichromene (CBC). By using petroleum ether dichloromethane (1∶1) as the developing solvent, iodine and 1% Vanillin ethanol sulfuric acid (10∶1)were used to establish the TLC method for CBD respectively. High performance liquid chromatography (HPLC) detection method for CBD was also established by using acetonitrile 0.05% phosphoric acid solution (80∶20) as mobile phase and selecting the detection wavelength with high CBD absorption peak, which has a good linear relationship at 3.125~100μg/ mL (R2=0.9997), the average recovery rate is 103.69% and RSD is 1.32% (n=5).

Abstract:In order to explore the volatile components and their differences among five varieties of dried morels, the methods of headspace solid+phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was used to analyze the volatile components in varieties of M2, M3, M4, M5, and M6. The results showed that a total of 173 compounds were detected from 5 varieties, of which 134 were different compounds, including 31 alkanes, 19 alcohols, 16 aldehydes, 12 amines, 9 acids, 8 olefins, 8 esters, 6 ketones, 4 benzenes, 4 pyrazines, 3 alkynes, 3 furans, and 12 others. There are 46 kinds of non characteristic compounds in 2 or more varieties, and the relative content in each variety was 70.13%～90.15%. A total of 88 kinds of characteristic compounds were detected in only 1 variety and the relative contents of which was 9.85%～29.87%. The PCA analysis indicated that the difference in the size of volatile components among varieties showed consistent characteristics with the close relationship among them. The results showed that the characteristic compounds are few kinds but higher contents, which is the main volatile components of the morel. The non characteristic compounds contents are low but more species, and it is the reason for the difference of aroma components among different varieties.

Abstract:A UPLC method has been developed in the current investigation for simultaneous determination of four main iridoid glycosides, which were verproside, catalposide, amphicoside and 6-O-veratroylcatalposide in Veronica ciliata Fisch. The separation was performed at 40 ℃ on Waters ACOUITY T3 column (100 mm×2.1 mm, 1.8 μm); the mobile phase was acetonitrile-water(0.1% formic acid+2.5 mmol ammoniumformate); the flow rate was 0.4 mL/min and the detection wavelength was 260 nm. The results showed that the calibration curves were the good linear relationships in the range of 1.562～50 μg/mL (R2＝0.9987) for verproside, 1.562～50 μg/mL (R2＝0.9989) for catalposide, 4.689～143 μg/mL (R2＝0.9996) for amphicoside, 1.562～50 μg/mL (R2＝0.9998) for 6-O-veratroylcatalposide, the average recovery rate were 100.21%(RSD=1.3%), 99.43% (RSD=1.8%), 100.6% (RSD=2.5%), 102.7% (RSD=0.65%),respectively. The method is simple, sensitive, economical and reliable, and can be used for quality control and evaluation of Veronica ciliata Fisch.

Abstract:In order to provide a basis for hybridization combination of parent materials and molecular assisted breeding, the genetic diversity of parent materials was analyzed by using SSR markers and their association with some agronomic traits. The genetic diversity analysis and population genetic structure analysis of 190 rice materials were analyzed using 60 pairs of SSR markers distributed in 12 chromosomes of rice. On this basis, the correlation analysis between the marker and agronomic traits was carried out using GLM and MLM of Tassel 3.0. The results showed that the genetic similarity coefficient (GS) variation of 190 rice materials ranged from 0.62 to 0.97 with an average of 0.86. According to the genetic structure of the opulation, the tested materials could be divided into three subgroups. With GLM analysis, 8 markers associated with spike length, a branch number, primary branch grain number, secondary branch number, secondary branch grain number, the total number of grains/ear and not full grain associated tag were found, and the tag on the interpretation of the phenotypic variation rate was 0.0648. In the MLM system analysis, the explanatory rates of phenotypic variation by 8 markers ranged from 0.0378 to 0.0648. The molecular markers lated to these eight agronomic traits obtained in this study will provide a theoretical basis for markerassisted breeding of high yielding rice varieties.

Abstract:In order to study the members and classification of the AP2/ERF transcription factor family of Salix suchowensis, and to further explore its function in the growth and development, the AP2/ERF family genes were identified, classified, chromosomed, and their physical and chemical properties, gene structure, conserved domains, and expression patterns were also analyzed using bioinformatics techniques and methods. The results showed that Salix suchowensis contains 178 AP2/ERF genes, which were classified into four subfamilies: AP2, ERF, RAV, and Soloist according to the evolutionary relationship between the AP2/ERF conserved domain and the AP2/ERF genes of Arabidopsis thaliana. In addition, the results of tissue expression pattern analysis showed that the AP2/ERF family genes had obvious tissue specificity, it was strongly expressed in leaf, root, shoot, and flower, and weakly expressed in other tissues.

Abstract:To the problem of prior knowledge and lack of semantic understanding in the traditional model of document level sentiment analysis, this paper proposes an sentiment analysis model called TWEANN（Attention Neural Networks based on Topicenhanced Word Embedding）, which is based on attention mechanism and hierarchical network feature representation. The word2vec model based on CBOW is used to train the word vector for corpus and the sparsity in the word vectors is reduced, the document topic distribution matrix is computed with LDA algorithm based on Gibbs sampling, the more complete text context information are obtained through hierarchical LSTM neural network and the deep sentiment features are finally extracted. The document topic distribution matrix is used as the model attention mechanism to extract the document features and the sentiment classification is thereby implemented. The experimental results show that the proposed TWEANN model has better classification results, compared with the TSA and HAN models. The F values on the Yelp2015, IMDB, and Amazon datasets is increased by 1.1%, 0.3%, and 1.8%, respectively, and the RMSE values on the Yelp2015 and Amazon datasets increased by 1.3% and 2.1%, respectively.

Abstract:In order to solve the airport surface confliction problem in large airports, a variable structure interacting multiple model algorithm based on runwaytaxiway system constraint and ATC order constraint is applied to the tracking of field targets. We first establish the methods for mathematical modeling of complex taxi structures, tracking status fixing under the taxi structure constraint, and adaptive matching of aircraft and taxiing system based on ATC order constraint. In dealing with the runwaymatching and modelswitching, the maximum a posteriori (MAP) estimations of runwaytaxiway system constraint and ATC order constraint are utilized to activate and terminate the model set. A new method, which combines the variable structure interacting multiple model with the MAP, has been proposed for improving the tracking performance. Simulation results demonstrate that the proposed method is more effective than the interacting multiple model and the variable structure interacting multiple model, leading to superior tracking accuracy.

Abstract:The acoustic thermometry has a good application in the special temperature field environment. That is, the continuous distribution of temperature field can be reconstructed using the flight time spent on the finite ultrasonic propagation path. The least square method is one of the acoustic temperature field reconstruction algorithms, and the reconstructed temperature field will have the phenomenon of missing edge information using this method. In order to solve this problem, an algorithm based on Reflected Sigmoid radial basis function interpolation is proposed to reconstruct the twodimensional distribution of temperature without information loss. In this algorithm, the least square method is adopted to determine the temperature matrix and the ReflectedSigmoid function is used to interpolate the temperature field. The reconstruction results and error analysis of two typical single peak temperature field models show that the root mean square percentage error of the symmetrical single peak temperature field is 1.6% and the root mean square percentage error of the skewed single peak temperature field is 3.5% after complementing the edge of the temperature field.

Abstract:All homomorphic encryption schemes proposed so far suffer from a very large ciphertext expansion, which is a very significant bottleneck in practice. In order to improve the transmission efficiency, Naehrig et al. proposed an idea of hybrid encryption, i.e. a user encrypt some plaintext m with a symmetric encryption scheme E under some private key k, and encrypt the private key k with a homomorphic encryption scheme under some public key pk, transmit a much smaller cipertext c′=(HEpk(k),Ek(m)) that cloud decompresses homomorphically into the HEpk(m) through a decryption circuit CE-1. In this paper, we extend the Fully Homomorphic EncryptionSymmetric Encryption framework into a batch one, i.e. we use the Chinese Remainder Theorem to pack l ciphertexts Ek(m0),…,Ek(ml-1) into a single C, send C′=(HEpk(k),C) to the cloud. Given C′, cloud only needs to homomorphically evaluate CE-1 for once to recover all HEpk(mi), rather than l times in original scheme. By this way, we can greatly reduce the times of homomorphically evaluating decryption circuit, which costs a lot of computation. We also give out an instance of batch GSW13FLIP scheme to explain in detail. Comparing to original scheme, our batch scheme can reduce the computational complexity from O~(λ3) to O~(λ2), where λ is security parameter of FLIP.

Abstract:Aiming at the accuracy and robustness requirements of target tracking algorithm, we propose a visual target tracking algorithm based on improved particle filter. First, the target appearance model is described by establishing a variety of features, and the weighting coefficients of each feature component are adaptively adjusted. Then, we exploit the classification resampling method to solve the problem of particle degradation and scarcity in the original resampling method. Finally, a new template updating mechanism is proposed, which can adaptively select moving templates or original templates. The experimental results demonstrate that the improved algorithm has good tracking accuracy and robustness on the challenging tracking video sequences, and it can cope with the complex conditions such as low resolution of video images, rotation change of target, partial occlusion and so on.