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The State and Prospects for Copper Tailings as Resources
CHEN Yu - feng, LU Xiao - yan (1. Hehai University, Nanjing 210098, China; 2. Nantong University, Nantong 226007, China)This paper expatiates the dangers caused by copper tailings, and their utilization state for copper tailings is summarized . In the end, the measures of using copper tailings in a reasonable way are put forward.
IC Layout Design Based on the Platform of Zeni EDA Software System
SHI Min, XU Chen (Nantong University, Nantong 226007, China)The integrated circuit layout design process based on the platform of Zeni EDA software system produced by China Integrated Circuit Design Center is introduced. This article discusses some principles of IC layout design placement, cell location and wiring. The practice has showed that Zeni EDA tools are capable of IC layout design for teaching, research and commercial-
Spatial correlation analysis of carbon emissions from residential energy consumption in China from the perspective of complex networks
PENG Xinbei;LIU Jiabao;How to achieve the dual carbon goals of "peak carbon and carbon neutrality" and promote the development of a low-carbon economy has become a major issue that needs to be addressed in China′s economic and social development. In the perspective of complex networks, based on the carbon emissions data of residential energy consumption in China′s provincial regions from 2005 to 2020, spatial econometrics and social network analysis methods are used to study the spatial correlation of residential energy consumption carbon emissions in China from both spatial distribution and network association aspects. The results show that the carbon emissions from residential energy consumption in China exhibit obvious spatial clustering, with significant high-high clustering and low-low clustering among provincial regions, demonstrating positive spatial autocorrelation. Moreover, the spatial correlation of residential energy consumption carbon emissions in China is not only related to geographical distance but also exhibits a complex network structure. The degree of spatial correlation of carbon emissions from residential energy consumption decreases from the eastern, central, to western regions of China, with the eastern coastal provinces serving as network centers exerting strong control over other provinces, while the provinces in the central and western regions are located at the network periphery and have weaker control over other provinces. The findings can provide effective references for relevant departments to assess the emission reduction responsibilities of each province and develop targeted collaborative emission reduction plans.
Survey of few-shot learning methods for specific emitter identification
GUI Guan;TAO Mengyuan;WANG Cheng;FU Xue;WANG Yu;With the proliferation of technologies such as 5th-generation mobile communication and the Internet of things, there has been an explosive growth in the number and types of emitters. Consequently, the recognition performance of traditional specific emitter identification(SEI) technology, which relies on statistical features and machine learning, is challenging to achieve practical application levels. Inspired by the remarkable performance of deep learning in fields like computer vision and natural language processing, numerous researchers have applied deep learning to SEI, yielding fruitful research outcomes that substantiate the effectiveness of deep learning-based SEI methods. Data is one of the fundamental pillars of deep learning, implying that deep learning-based SEI methods typically require extensive and high-quality electromagnetic signal samples for the training process. However, obtaining and accurately labeling massive and high-quality electromagnetic signal samples in complex and dynamic electromagnetic environments is difficult and expensive. Consequently, some researchers have focused on the problem of few-shot learning for specific emitter identification. To elucidate the current status of few-shot learning-based SEI methods and facilitate research and development in the context of few-shot scenarios, this paper comprehensively investigates and summarizes recent few-shot learning-based SEI methods conducted both domestically and internationally. Firstly, the existing few-shot learning-based SEI methods are classified based on whether auxiliary electromagnetic signal samples are utilized in the training process, accompanied by a description of the corresponding problem formulations. Subsequently, a summary of the existing research work is presented, followed by relevant experimental simulations and an analysis of the existing challenges and future directions.
Preparation and piezoelectric properties of bacterial cellulose/chitosan/barium titanate aerogels
WANG Yijie;SU Xin;SUN Yingying;FU Yijun;ZHANG Wei;LI Dawei;To prepare piezoelectric sensors with good mechanical and piezoelectric properties, BC/CS and BC/CS/BT-OH composite aerogels were fabricated using bacterial cellulose(BC) and chitosan(CS) as the aerogel matrix and hydroxylated barium titanate nanoparticles(BT-OH) as the piezoelectric material via freeze-drying. The surface morpho-logy, chemical structure, mechanical properties, and piezoelectric properties of the composite aerogels were characte-rized by scanning electron microscopy(SEM), Fourier transform infrared spectroscopy(FTIR), X-ray diffraction(XRD), a universal testing machine, and an electrometer. The results showed that the incorporation of BT-OH into the BC/CS composite aerogel rendered the internal structure more porous and the surface microstructure rougher, with BT-OH nanoparticles uniformly distributed throughout the composite. FTIR and XRD analyses confirmed the successful hydroxylation of BT nanoparticles. When the BT-OH mass fraction was 2.0%, the BC/CS/BT-OH composite aerogel exhibited optimal mechanical performance, achieving a compressive stress of 77.69 kPa at 70% strain, which was1.93 times that of the BC/CS composite aerogel under the same strain condition, demonstrating excellent fatigue resistance. The introduction of BT-OH also enhanced the piezoelectric output. At a BT-OH mass fraction of 2.0%, the output voltage and current of the BC/CS/BT-OH aerogel both reached 3.56 times those of the BC/CS composite aerogel.
Low spatial back electromotive force harmonics design for fractional-slot winding permanent-magnet motor
ZHENG Junqiang;XU Haoen;ZHANG Yuting;MAO Jingfeng;Fractional-slot winding permanent magnet motors(PM) are widely applied due to their unique advantages,with the most notable being their high-quality sinusoidal no-load back electromotive force(EMF) waveform. This characteristic not only enhances the control performance of the motor system but also significantly reduces torque ripple and operational losses, thus improving overall motor quality. Firstly, a comparative analysis of the structural characteristics and magnetic circuit features of integer-slot and fractional-slot winding PM motors was conducted. Next, based on winding functions and air-gap flux density functions, a general expression for the no-load back-EMF of permanent magnet motors was derived. From the perspective of spatial harmonics, the intrinsic impact of the fractional-slot winding structure on optimizing the no-load back EMF waveform of PM motors is elucidated. To validate the theoretical analysis, an optimized design of a 24-slot 8-pole integer-slot winding PM motor and a 27-slot 8-pole fractional-slot winding PM motor is performed. The winding factor harmonics, air-gap flux density harmonics, no-load back EMF,and torque performance of both motors were comparatively analyzed. The findings indicate that the k-th harmonic of the no-load back EMF is generated by the no-load air gap magnetic density harmonic of the order kpr-th(where pris the number of PM pole pairs) and the winding factor harmonic of the order v=kpr. The presence of more harmonics of the same order in the winding factor and air-gap flux density increases the harmonic content in the no-load back EMF. Finally, a prototype of the 27-slot 8-pole fractional-slot winding PM motor was developed and partially tested,measuring the motor′s no-load back-EMF waveform, phase current, and torque performance. These experimental results were compared with finite element predictions to confirm the accuracy of both the theoretical analysis and the finite element simulations.
Comparison and Analysis of Several Digital Reverberator Models
ZHOU Jing-jie,CHEN Jian-ping,JI Xiao-dong(School of Electronics and Information,Nantong University,Nantong 226019,China)Several models of digital reverberators from a simple comb-filter reverberation model to a more complex Moorer reverberation model are presented.The principles,structures and parameters of these models are analyzed and investigated respectively and their implementations and simulations are conducted with Matlab.The merits and demerits of the different models are compared according to impulse responses and frequency characteristics of the system.The research results show that the all-pass filter reverberation model can achieve a certain quality of artificial reverberation effect and has a relatively simple structure,while the Moorer model has the best effect in terms of the naturalness of sound,but its structure and parameter design are more complicated.
Simulation of Fluctuating Wind Load on High Rise Tower and Analysis of Wind-induced Vibration Response
FENG Su, JIN Jiang (School of Architecture Engineering, Nantong University, Nantong 226007, China)Fluctuating wind load of each floor of the steel tower was simulated based on the resonance wave method. The steel tower structure is simplified as two-dimensional lumped mass model. Then, the wind-induced vibration response of the steel tower was calculated based on the transient dynamic module of ANSYS and the technical parameters of vibration control were provided.
Research on breakdown characteristics of 4H-SiC PIN avalanche diode in single-zone JTE terminal structure
CHEN Hongfu;WANG Yijin;YU Yanwei;CHEN Zhipeng;HE Jiacheng;GAO Zijian;LUO Man;YU Chenhui;As the third generation of wide band gap semiconductor material, SiC has high critical electric field, high thermal conductivity and other characteristics, and the PIN power diode devices made from this material can meet the requirements of high pressure, high temperature and radiation resistance in high-speed rail transportation, aerospace and other fields. At present, the traditional 4H-SiC PIN avalanche diode is susceptible to edge field crowding effect,which leads to the early breakdown of the device. In order to reduce this effect, Sentaurus TCAD software is used to study a 4H-SiC PIN avalanche diode with single-zone junction termination extension(JTE) structure, on this basis,the effects of the transverse length of JTE layer and doping concentration on the breakdown characteristics of the diode are analyzed emphatically. The maximum external breakdown voltage of 4H-SiC PIN diode with single-zone JTE terminal structure is about 1 670 V, which is 87% of the theoretical breakdown voltage. Compared to the 267.5 V breakdown voltage of traditional device, the single-zone JTE diode has better voltage resistance and higher reliability.
AHP on the Basis of Index Number Scale and Its Usage
SHI Jian, GUO Yue-hua (Nantong University, Nantong 226007, China)This paper not only analyzes the blemish of 1 - 9 scaling method, but also introduces an accurate index number scale and discusses the ratings of the degree of importance and the determination of the ratio of importance a. By introducing objective judgment and avoiding subjective judgment, we have improved the AHP of T.L Saaty's. In the end, the conditions of economic development in the six counties of Nantong Prefecture are put into order according to the data offered.