Reference Value For Application Research Articles

Temperature-tunable terahertz metamaterial device based on VO2 phase transition principle.

Terahertz devices play an irreplaceable role in the development of terahertz technology. However, at present, it is difficult for most natural materials to respond in the terahertz band, making the devices made of them perform poorly. In order to realize the diversity and tunability of device functions, we designed a terahertz metamaterial device composed of the thermally-induced phase change material VO2. The device structure is composed of a Au bottom layer, a SiO2 dielectric layer and a VO2 top layer. Through software simulation, we found that when T = 313 K, the device has complete reflection ability in the whole terahertz band. When T = 342 K, the average absorptivity is above 95% in the ultra-wide band range of 4.71-9.41 THz, and the absorptivity reaches an amazing 0.99999 at 6.31 THz. Thus, the maximum thermal modulation range of the device is 0.001-0.99999. The Bruggeman effective medium theory clarifies the phase transition characteristics of vanadium dioxide. The Drude model establishes the functional relationship between the conductivity of vanadium dioxide and temperature. The basic principle of high absorption was described using the impedance matching theory. We also drew the electric field intensity diagram during the temperature rise of the device to further confirm the reason for the change in the device performance. In addition, the influence of the absence of different structural layers on the absorptivity was simulated, which reflected the role of each layer structure more intuitively. We also explored the influence of the geometric size of the device on the absorptivity, which provided a certain reference value for practical application. In short, we have designed a tunable terahertz device with simple structure, high absorptivity, and wide absorption bandwidth, which can be used in the fields of energy collection, electromagnetic stealth, and modulation.

Operation status and line optimization of Wanda Plaza Parking lot

Vehicle parking is not only an important problem in urban traffic, but also an important factor affecting the relationship between cities and within cities. In this paper, by investigating the parking conditions of Jiaozuo Wanda Plaza in 2018, important parameters such as average parking time on weekdays and holidays, berth turnover rate, parking utilization rate and centralized parking index were obtained. Based on the obtained parameters, multi-angle optimization analysis was conducted on the parking lot. In order to reduce the congestion of the entrance and exit of parking lots and improve parking efficiency, this paper adopts the method of increasing the entrance and exit of parking lots and optimizing the route. It has great reference value in practical application.

Design and Analysis of Permanent Magnet Parameters for Interior Permanent Magnet Synchronous Motor

For improving the performance of a 3 phase 6 pole 48 slot 55kW interior “—” permanent magnet synchronous motor, the permanent magnet parameters are optimized by using finite element simulation software with the variables of permanent magnet embedding depth, permanent magnet thickness and pole arc coefficient. In order to reduce the torque of the motor slot and increase the no-load counter electromotive force within the allowable range, the permanent magnet parameters are optimized. The results show that the motor has the best performance when the depth of permanent magnet is 251mm, the thickness of permanent magnet is 19mm and the polar arc coefficient is 0.8mm.This research result has certain reference value in practical application.

Research on the Risk Early Warning of Construction Engineering under the Coupling Disaster of Typhoons and Rainstorms in Coastal Areas Based on BP Neural Network

Deng, J., 2020. Research on the risk early warning of construction engineering under the coupling disaster of typhoons and rainstorms in coastal areas based on BP neural network. In: Hu, C. and Cai, M. (eds.), Geo-informatics and Oceanography. Journal of Coastal Research, Special Issue No. 105, pp. 151–154. Coconut Creek (Florida), ISSN 0749-0208.The coupling of typhoon and rainstorm is one of the main natural disasters that often occur in coastal areas at present. It often causes damage to buildings, infrastructure, trees, and even casualties. Therefore, this paper takes coastal areas as the research object to carry out the risk early warning research of construction engineering under the coupling effect of typhoon and rainstorm. Based on back propagation (BP) neural network, this paper constructed a risk early warning model for building engineering, and established the early warning index system of risk, which contains 24 influencing factors. In this paper, 13 construction projects affected by Typhoon Meranti (1614) were selected as risk assessment samples, and the training data and test data of the model were obtained through expert scoring method. BP neural network learning algorithm based on error inverse propagation was used to train the model. The trained risk warning model was used to predict the coupled risk level of typhoons and rainstorms for a construction project in coastal areas. Through simulation calculation, the simulation results were consistent with the actual risk of the project suffering from the coupled disaster of typhoons and rainstorms. The results show that the risk early warning model based on BP neural network has reference value in practical application, which can provide decision support for government departments and relevant construction units to implement disaster prevention and reduction, and take effective measures to minimize the disaster losses caused by typhoons and rainstorms coupled.

Convergence Adjustment Method Based on Approximate Power Flow and Voltage Stability

Prone to problems flow calculation does not converge at the scheduled maximum power operating mode, the current operating personnel inability to visually observe the system state, convergence can only be adjusted by trial and error approach. Solving the problem of non convergence of power flow plays an important role in power system analysis. Based on the intermediate process of solving the Newton method, the concept of an approximate fashion, the relation between convergence and voltage stability is calculated by analyzing the trend of the voltage characteristics similar trend as the main basis of the judgment result in the trend does not converge, based on voltage sensitivity further, by improving the convergence of the method to boost the voltage level indirectly. Finally, after the New England 39-bus system to verify, by demonstrating the relevance and accuracy of the proposed method. When not solve the problem of the convergence trend is not impressive, it has a certain reference value for practical application. This study has a good application prospect in practical engineering application

Factors Influencing Regional Economic Vitality Based on Regression Analysis

The urban economic vitality refers to capacity and potential of urban economic development. At present, Chinese cities are in a period of rapid growth, the vitality of urban economy has become a driving force for attracting talents, urban construction and sustainable regional development. Based on multiple stepwise regressions, this paper quantitatively analyzes the current regional economic vitality and future development from different regions and different perspectives. This paper models and analyzes the economic vitality of different provinces of China from six aspects: population change, corporate development vitality, regional development, regional environment, industry development, and income level. The results show the increase of urban population and population density is conducive to the enhancement of regional economic vitality, and the absorption of enterprises can drive the regional economic growth. We use propensity score matching to calculate the change of the growth rate of the number of enterprises after the implementation of the policy, and analyze the short-term and long-term effects of changes in economic policy factors on regional economic vitality. This paper quantifies the key factors affecting the survival of urban enterprises, and provides theoretical support for promoting urban economic vitality. Finally, we tested the model, verified the rationality of the results, and extended the scope of application of the model, which has certain reference value in practical applications.

Analysis of corona discharge current trigger threshold for different shapes metal tips

Aiming at the problem of the corona discharge trigger electric filed threshold at different shapes of a metal tip, through the theoretical analysis of the electric field distribution near the surface of the conical tip and the ellipsoidal tip, and the laboratory simulation experiment, reached the following conclusion. The relationship between the value of corona current amplitude, the frequency and the tip’s radius of curvature is obtained; the corona discharge electric field threshold is relatively fixed and between 6.9382 kV/cm and 8.2824 kV/cm. The above relationship has a certain reference value in practical application and computer simulation.

The Design of C-Language Graphics Library Functions Based on JRD320240B

The paper mainly introduces C-language graphics library functions based on JRD320240B. For example, it can display Chinese word, character list, painting line and picture on any point of the LCD. And gives the corresponding hardware interface circuit, software flow diagram of C8051F020 and JRD320240B.The paper has reference value in practical application.

Zeolite and fungi’s flocculability of simulated wastewater containing heavy metal ions or phosphorus

This paper focuses on the flocculability of simulated wastewater containing heavy metal ions (Fe3+, Cd2+) or phosphorus by zeolite, microbial flocculants (MBF) produced by Aspergillus niger and the composite flocculant composed of zeolite and MBF. The main results are presented as follows: zeolite was a good flocculant when the contamination of the three simulated wastewaters was low, but the treated water is of turbidness and the particles in it are hard to precipitate. The MBF have a good flocculability toward Fe3+ wastewater, as well as particulate matter. Significant changes in flocculability occurred after adding the composite flocculant in different simulated wastewaters, the best or least effect respective for Fe3+ and Cd2+ wastewater. The research we have done shows that the method by which the composite flocculant is used to treat the wastewater containing heavy metal ions or phosphorus provides important reference value for practical application.