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In this paper, a comparative study was conducted on the aerobic fermentation of kitchen waste pretreated by thermal hydrolysis and three different excipients, the dynamic changes of temperature and organic matter of kitchen waste after thermal hydrolysis were measured during aerobic fermentation with peanut shell, corn stalk and corn cob as additives, and high-throughput sequencing was performed on the samples of the three excipients in the high temperature fermentation stage to identify the dominant bacterial community in the high temperature region of different excipients. The results showed that the dominant bacterial communities of peanut shell, corn stalk and corn cob were similar at the phylum classification level. Among them, Ascomycota accounted for 97.68%, 99.55% and 99.98% in HS, YM and YX treatment groups, respectively, which means it was the absolute dominant fungal phyla in high temperature fermentation stage. At the level of genus classification, there were differences among the dominant bacterial genera in each group. The main bacterial genera in peanut shell treatment group were Aspergillus, unclassified_f__Dipodascaceae, Penicillium, unclassified_o__Sordariales, Candida and Diutina. The main bacterial genera in corn stalk treatment group were Candida, Aspergillus and Penicillium. The main bacteria in corn cob treatment group was unclassified_o__Sordariales. The percentage of saprophytic fungi in HS, YM and YX high-temperature treatment groups was 96.40%, 99.25% and 99.97%, respectively. Saprophytic fungi played a major role in the high-temperature fermentation stage.

The assembly shop production scheduling of complex electromechanical products is a typical discrete variable NP-hard problem. In order to solve the assembly job scheduling problem of a large transformer assembly shop, an improved particle swarm algorithm is used to solve the optimal assembly task scheduling result. In order to minimize the maximum completion time, the traditional particle swarm optimization (PSO) algorithm was improved according to the characteristics of large transformer assembly process. First, the two-stage coding method of process and assembly team is adopted. Then, in order to improve the quality of the initial solution, the initialization method that minimizes the completion time is selected, and the adaptive inertia weight optimization speed update formula is adopted. Finally, the simulation study is carried out with relevant example data. Compared with the traditional PSO, the maximum completion time and convergence speed are significantly improved, which verifies the effectiveness of the improved PSO, and obtains the production scheduling Gantt chart of the workshop.

This paper mainly focuses on the problem of low recognition rate and making deep hidden features unable to learn caused by the lack of training samples in intricate facial recognition, a method of virtual image sample generation is proposed. The starGAN network based on style migration is used to generate the image that does not exist in the original database, and multiple images with different facial attributes are added to a single sample, combine the obtained virtual samples with the original database to build a larger face database for face recognition. Experiments on the CelebA face database show that the proposed method can effectively improve the face recognition rate in complex situations.

In view of the fact that vegetable harvesting in my country is still manual harvesting, with large labor force and low efficiency, a universal harvesting machine for stem and leaf vegetables has been developed. This machine has the advantages of simple operation and high efficiency. This article focuses on the machine design, working principle and technical situation of the harvester for stem and leaf vegetables. The modified machine has been verified by practice and realized the predetermined design function.

In recent years, with the development of science and technology, computer numerical control machining and mechanical mold manufacturing technology has also had a great development[1].Higher requirements are put forward for mechanical die, such as structure complexity, profile complexity, material hardness and precision.In the mold manufacturing, the machine mold numerical control machining technology has the extremely important function.This paper analyzes the machining and manufacturing technology of machine mould by computer numerical control and its application in manufacturing.Finally, the development trend of CNC machining technology for mechanical die is analyzed.It is hoped that the research of this paper can promote the application of nc machining technology in die manufacturing industry.

Coalbed methane (CBM) is one of elements of coal mine hazards, the high CBM content and low permeability coefficients of coal seams in Huainan coal filed result in high difficulty of coal exploitation and CBM drainage, and the potential risk of gas explosion and combustion. The CBM drainage works are time-consuming and they typically delay the coal mining operations. A set of novel techniques of rapid co-extraction of coal and CBM are proposed in this paper. In the practice of 1413A longwall panel of Zhangji coal mine, a set of overlying and underlying drainage galleries were replaced by two overlying drainage galleries which were excavated by TBM, thereby the stress of excavation works was reduced. The pre-drainage and roadway excavation are conducted simultaneously and the overlying drainage gallery can also be used for post-drainage purposes. The bolter miners and automatic or remote control of longwall mining have also been used in the practice. The 1413A longwall extracted 2.31 million tons of coal and 15.02 m3 of CBM with the extraction rates of 93.5% and 63.8% respectively in 448 days. The speed and efficiency of co-extraction operations were improved significantly.

In TBM excavation projects of Zhangji coal mine which is the first application of TBM at deep underground coal mine, computational modelling was conducted in surrounding rock stability study and support design of coal mine TBM excavated roadway due to lack of experience in similar projects. This paper presents a support design methodology of TBM excavated roadway at deep underground coal mine. A three-dimension finite element model was established, and the non-uniform tectonic stress filed was also been simulated in the model. Stress redistribution, displacement and plastic zone range of surrounding rock under different support patterns were analyzed and support design of the roadway was made on the base of simulation results. During roadway excavation, instrument rock bolts were installed for monitoring stress distribution and roadway convergence. The monitoring results suggest that computational simulation results correspond with in-situ monitoring data, horizontal stress concentrates on the roof and floor of roadway and vertical stress concentrates on lateral sides. The roadway convergence increased significantly after excavation and then slowed down and finally stopped after 40 days.

Magnetoelectric composites have attracted much attentions due to their excellent multiferroic properties at room temperature. In this paper, CoFe2O4-PbZr0.52Ti0.48O3 (CFO-PZT) composite ceramics with different molar ratios (CFO/PZT = 1:4, 1:5, 1:6 and 1:7) were prepared by conventional solid reaction method. Effects of molar ratio on the structure, dielectric, ferroelectric and magnetic properties were comparatively investigated. X-ray diffraction patterns confirmed bi-phase structures of the composites, which can be indexed as CFO and PZT, no other obvious phase can be found with the limitation of the XRD resolution. Scanning electron microscopy (SEM) images show that the surface of the prepared samples is not dense enough and many pores are formed, the mean grain size is about 200 nm. The same relaxation behavior was observed in the intermediate temperature range of PZT-CFO composite ceramics. At room temperature, the dielectric constant and dielectric loss of the specimen 1:4 are the highest. The leakage current of the sample 1:4 is the lowest while the sample 1:6 has the largest value. As the CFO content in the composite decreases, both the saturation (Ms) and the remnant (Mr) magnetization decrease. Among them, the sample 1:4 presents better ferroelectric and magnetic properties, the remnant polarization is 1.13 μC cm−2, the saturation magnetization and remnant magnetization are 11.01 and 3.28 emu g−1, respectively. The sample 1:6 has the largest coercive field (945.27 Oe) while the sample 1:7 show the smallest value (681.19 Oe). Interface interaction between CFO/PZT may be applied to explain this phenomenon.

We investigate nonlinear interaction of nitrogen molecules with a two-color laser field composed by an intense 800 nm laser pulse and a weak 400 nm laser pulse. It is demonstrated that the spectrum of 400 nm pulses is dramatically broadened when the two beams temporally overlap. In comparison, the spectral broadening in argon is less pronounced, although argon atoms and nitrogen molecules have comparable ionization potentials. We reveal that the dramatic spectral broadening originates from the greatly enhanced nonlinear optical effects in the near-resonant condition of interaction between the 400 nm pulses and the nitrogen molecular ions.

Ni0.5Cu0.5Fe2O4/BaTiO3 (NCFO/BTO) mixed multiferroic fluids were prepared by distributing surfactant treated NCFO and BTO particles in to a highly-insulating base fluid, the magnetocapacitance and magnetoelectric coupling effect were investigated. The results indicate that the sample shows strong magnetoelectric coupling effect, in which both the coercive field E c and remanent polarization P r enhance obviously under the action of magnetic field, while the dielectric constant decreases with increasing the magnetic field, revealing negative magnetocapacitance phenomenon. Large direct magnetolectric coupling coefficient was estimated to be α ~ 76 V/(cm−1.Oe), which is several orders of magnitude larger than that of conventional magnetoelectric composite ceramics. Further analysis indicates that the possibility of movement, aggregation and chain-like structure of the particles in the presence of external field is believed to be responsible for the observed negative magnetocapacitance and strong magnetoelectric coupling effect. The results show that the strong room temperature magnetoelectric effect of the mixed magnetoelectric fluids is the product of the deformation of the particle distribution and the utilization of clamping force under external field. This magnetoelectric coupling effect is different from that of conventional composite materials which is directly coupled via the interface interaction, which will be advantageous for practical applications.

In this paper, designed a swirling feeder for biomass tar, The numerical simulation of flow characteristics and temperature field heat transfer characteristics of the internal flow field was performed. Mixture multiphase flow model and Reynolds stress turbulence model are used, in the case of different feed flow ratios, Solved the internal flow field, concentration field and temperature field; Through research shows that when the flow ratio i = 0.6 ~ 0.8, Biomass tar can enter the reactor through the feeder without causing coking.

Progressive damage models based on continuum damage mechanics are used in combination with cohesive elements to explore the effect of three different failure criteria including Chang-Chang, Hashin and Puck criteria, on the structural response and the failure mechanisms of composite laminates subjected to low-velocity impact. Three different failure criteria and damage evolution laws based on equivalent strain are used for intralaminar damage models, and the delamination is simulated by the bilinear cohesive model based on quadratic criteria. A new numerical optimization method combining analytical approximation and Golden section Search has been applied in Puck criteria to search the fracture plane. Numerical analysis is performed on two composite laminates specimens with different materials, layups and impact energy to study the impact force-time, force-displacement and absorbed energy, computational cost, as well as the damage evolution behaviors of fiber, matrix and delamination. The numerical results with three different failure criteria show acceptable accord with available experimental data, which validate the accuracy of the proposed damage model. Moreover, this research can be helpful to select appropriate failure criteria in the progressive failure analysis of composite laminates under low velocity impact.

Controlling the growth direction (planar versus vertical) and surface-to-bulk ratio can lead to lots of unique properties for two-dimensional layered materials. We report a simple method to fabricate continuous films of vertical Bi2Se3 nanoplates on Si substrate and investigate the quantum transport properties of such films. In contrast to (001) oriented planar Bi2Se3 nanoplate film, vertical Bi2Se3 nanoplate films are enclosed by (015) facets, which possess high surface-to-bulk ratio that can enhance the quantum transport property of topological surface states. And by controlling the compactness of vertical Bi2Se3 nanoplates, we realized an effective tuning of the weak antilocalization effect from topological surface states in Bi2Se3 films. Our work paves a way for exploring the unique transport properties of this unconventional structure topological insulator film.

Carrier-envelope phases (CEPs) from a kHz repetition rate, non-CEP stabilized laser system are measured and tagged with two different methods: an f–2f interferometer and a stereo-above-threshold-ionization carrier-envelope-phase-meter. Both methods utilize the octave spanning spectrum generated in the hollow-core fiber (HCF) that broadens the laser spectrum to produce few-cycle pulses. Phases from both methods are carefully synchronized and compared on a single shot level. The results show that the CEPs measured by both methods are in good agreement and demonstrate that a HCF based f–2f interferometer is well suited for CEP tagged experiments.

A novel design for a velocity-map imaging (VMI) spectrometer with high resolution over a wide energy range surpassing a standard VMI design is reported. The main difference to a standard three-electrode VMI is the spatial extension of the applied field using 11 electrodes forming a thick-lens. This permits measurements of charged particles with higher energies while achieving excellent resolving power over a wide range of energies. Using SIMION simulations, the thick-lens VMI is compared to a standard design for up to 360 eV electrons. The simulations also show that the new spectrometer design is suited for charged-particle detection with up to 1 keV using a repeller-electrode voltage of -30 kV. The experimental performance is tested by laser-induced ionization of rare gases producing electrons up to about 70 eV. The thick-lens VMI is useful for a wide variety of studies on atoms, molecules and nanoparticles in intense laser fields and high-photon-energy fields from high-harmonic-generation or free-electron lasers.

We have investigated the spectral splitting of high harmonics generated in a semi-infinite gas cell. By performing an EUV–IR cross-correlation experiment, we are able to use the phase behaviour of the different sub-peaks of each harmonic to identify them with different electronic trajectories. Both microscopic and macroscopic analyses of the spectra effects are made. The identification of a particular trajectory with a particular component of the splitting on the basis of a single-atom model is found to be incorrect, while the full macroscopic treatment is in agreement with the experiment.

A series of SnO-coated α-Fe solid-solution nanocapsules were fabricated by a modified arc-discharge technique from Fe1−x Sn x targets with x = 0, 2, 3, 4 and 5 at%. The core and shells change with changing Sn concentration (0, 2, 3, 4 and 5 at%) in the Fe1−x Sn x targets used in the preparation. An in-depth study of the complex permittivity and permeability reveals that the SnO-coated α-Fe solid-solution nanocapsules with 3 at% Sn exhibit excellent microwave-absorption properties among the present SnO-coated Fe solid-solution nanocapsules, due to a proper electromagnetic match in the microstructure, the strong natural resonance as well as dipolar polarization mechanisms.