International Journal of RF and Microwave Computer-Aided Engineering最新文献_第4页

Wide-Passband Microstrip Filters With Wide Stopband Based on Half-Wavelength Resonators Coupled by Short Connected Line 基于短连接线耦合半波长谐振器的宽带微带滤波器

IF 0.9 4区工程技术

International Journal of RF and Microwave Computer-Aided Engineering Pub Date : 2024-11-19 DOI: 10.1155/mmce/7924319

Chunfeng Fan, Jiahui Han, Ke Gong, Xuehui Hu, Qing Liu, Yufang Liu

{"title":"Wide-Passband Microstrip Filters With Wide Stopband Based on Half-Wavelength Resonators Coupled by Short Connected Line","authors":"Chunfeng Fan, Jiahui Han, Ke Gong, Xuehui Hu, Qing Liu, Yufang Liu","doi":"10.1155/mmce/7924319","DOIUrl":"https://doi.org/10.1155/mmce/7924319","url":null,"abstract":"A novel and simple design method of wide-passband filters with wide stopband based on half-wavelength (λ/2) resonators coupled by a short connected line (SCL) is proposed and analysed in this paper. Different from the traditional parallel-coupled structure filters, SCL is proposed to realize a strong coupling between two adjacent resonators and suppress the parasitic passbands simultaneously. And the eigenmode analysis method and impedance ratio characteristics are both used to reveal the mechanism of wide-stopband implementation. To further expand the stopband, filters based on step-impedance resonators (SIRs) with SCL are proposed and analysed in detail. To verify the proposed design method and wide-stopband filtering structures, three 4-pole filters with uniform-impedance resonators (UIRs), SIRs with same impedance ratio, and SIRs with different impedance ratios are designed, fabricated, and measured. The proposed filters can realize a wide stopband up to 5.8f0 with rejection level better than 20 dB. Moreover, the proposed filters can easily realize a wide bandwidth.","PeriodicalId":54944,"journal":{"name":"International Journal of RF and Microwave Computer-Aided Engineering","volume":"2024 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/mmce/7924319","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142685375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

FA-UNet: Semantic Segmentation of Passive Millimeter–Wave Images for Concealed Object Detection FA-UNet：用于隐蔽物体检测的被动毫米波图像的语义分割

IF 0.9 4区工程技术

International Journal of RF and Microwave Computer-Aided Engineering Pub Date : 2024-11-16 DOI: 10.1155/2024/8628149

Huakun Zhang, Lin Guo, Deyue An, Odbal

{"title":"FA-UNet: Semantic Segmentation of Passive Millimeter–Wave Images for Concealed Object Detection","authors":"Huakun Zhang, Lin Guo, Deyue An,  Odbal","doi":"10.1155/2024/8628149","DOIUrl":"https://doi.org/10.1155/2024/8628149","url":null,"abstract":"Passive millimeter–wave (PMMW) scanners are widely used for personal security screening in public places due to their nonradiation and high real-time capabilities. However, the images obtained by these scanners frequently exhibit low signal-to-noise ratios and contrast, presenting challenges for automated detection systems. To address this issue, we propose an efficient semantic segmentation approach, FA-UNet, that employs a UNet architecture with a fusion attention mechanism to conduct binary classification (human body vs. background, including objects) for PMMW images. This approach incorporates a spatial attention mechanism into the lateral connections between the encoder and decoder and introduces a channel attention mechanism during the feature fusion process in the decoder. By combining these attention mechanisms, FA-UNet leads to more precise segmentation outcomes. The segmented image is then fused with the original image using our multistage fusion method, in which, first, the two images are blended in a 1:1 ratio for object detection. Then, a new fused image is obtained by adjusting the ratio within a certain range (0.3–0.5). Finally, the object detection results are overlaid on this fused image to generate a directly displayable image. We evaluate our method using a self-made dataset. Experimental results demonstrate that FA-UNet can accurately segment the human body region and preserve object shapes effectively. Using the fused image for object detection helps reduce false detections caused by background noise interference while improving the detection rate of weak targets. Additionally, the fused image aids in manual image interpretation in locations with higher security inspection levels and contributes to protect the privacy of individuals undergoing inspection to the greatest extent possible.","PeriodicalId":54944,"journal":{"name":"International Journal of RF and Microwave Computer-Aided Engineering","volume":"2024 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2024/8628149","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Miniaturized Ss-Shaped CP Circular Patch Antenna Design for Implantable Medical Device Applications 用于植入式医疗器械应用的微型 Ss 形 CP 圆形贴片天线设计

IF 0.9 4区工程技术

International Journal of RF and Microwave Computer-Aided Engineering Pub Date : 2024-11-16 DOI: 10.1155/2024/2742806

Muammer Omran, Changiz Ghobadi, Javad Nourinia, Majid Shokri

{"title":"Miniaturized Ss-Shaped CP Circular Patch Antenna Design for Implantable Medical Device Applications","authors":"Muammer Omran, Changiz Ghobadi, Javad Nourinia, Majid Shokri","doi":"10.1155/2024/2742806","DOIUrl":"https://doi.org/10.1155/2024/2742806","url":null,"abstract":"A small antenna is critical in wireless communication and monitoring of vital signs using data collected by implantable devices. Numerous studies address antenna miniaturization and reliability challenges while maintaining performance efficiency in this field. A reliable small-sized circularly polarized antenna of dimension (4.152 π × 1.28) mm3 developed for medical implants operating at the 1.4-GHz Wireless Medical Telemetry Service (WMTS) narrow band is presented in this work. The shorting pin, variable arc slots, and substrate and superstrate of high dielectric constant techniques were used. The proposed antenna underwent testing in a three-layer biological simulation environment that includes the skin, fat, and muscle. Subsequently, the antenna was fabricated, and measurements were performed by placing the antenna in beef biological tissues. The measurement results confirmed the simulated results. The antenna achieves an impedance bandwidth of 98 MHz (1.367~1.465 GHz, 7%). The effective axial ratio bandwidth (AR <3 dB) is 55.2 MHz (1.3668~1.422 GHz, 3.94%), which covers the CP operating frequency range. The simulation results attain a peak realized gain of −19.2 dBic. The communication link budget and the specific absorption rate (SAR) were analyzed. The results indicate that the radiation of the proposed antenna aligns with the safety limit of IEEE C95.1-1999 standards. The antenna exhibits excellent performance and reliability compared to other works operating within the 1.4-GHz WMTS band.","PeriodicalId":54944,"journal":{"name":"International Journal of RF and Microwave Computer-Aided Engineering","volume":"2024 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2024/2742806","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical Analysis of Therapeutic Effects by Varying Slot Numbers and Slot-to-Slot Distance in Microwave Ablation Using Multislot Coaxial Antenna 使用多槽同轴天线的微波消融中槽数和槽间距变化的治疗效果数值分析

IF 0.9 4区工程技术

International Journal of RF and Microwave Computer-Aided Engineering Pub Date : 2024-11-06 DOI: 10.1155/2024/8841831

Donghyuk Kim, Hyunjung Kim

{"title":"Numerical Analysis of Therapeutic Effects by Varying Slot Numbers and Slot-to-Slot Distance in Microwave Ablation Using Multislot Coaxial Antenna","authors":"Donghyuk Kim, Hyunjung Kim","doi":"10.1155/2024/8841831","DOIUrl":"https://doi.org/10.1155/2024/8841831","url":null,"abstract":"Microwave ablation (MWA) is based on the energy absorbed by biological tissue through microwave emission, which raises the temperature of the tumor to perform the treatment. MWA has the advantage of causing minimal bleeding and treating deep tumors. In this study, MWA for various slot design situations in a microwave coaxial antenna (MCA) was simulated through numerical analysis. For the slot design, the number of slots and the distance between slots were determined by the analysis parameters. A tumor developed inside the liver tissue was implemented, and the temperature distribution of the tumor and surrounding liver tissue was calculated for all cases selected for numerical analysis. The Helmholtz electromagnetic equation was used to calculate the electromagnetic field inside the tissue, and the modified Pennes bioheat equation was used to calculate the temperature change in the tissue due to the emitted microwave. Treatment effects were quantitatively analyzed for each slot design condition through an apoptotic variable based on the calculated temperature distribution. Lastly, conditions that produce optimal treatment effects were derived depending on the number of slots. The analysis showed that as the distance between the slots increased from 0.5 to 3.5 mm, the optimal treatment effect was obtained when the number of slots was 4, 3, 3, and 2, respectively, and the microwave input power at that time was 3.0, 2.8, 2.6, and 3.0 W, respectively. This is expected to allow for more rigorous and more therapeutically effective MWA.","PeriodicalId":54944,"journal":{"name":"International Journal of RF and Microwave Computer-Aided Engineering","volume":"2024 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2024/8841831","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study of Electromagnetic Radiation From High-Speed Train Voice and Data Antennae on the Health of Pacemaker Wearers 高速列车语音和数据天线的电磁辐射对心脏起搏器佩戴者健康的影响研究

IF 0.9 4区工程技术

International Journal of RF and Microwave Computer-Aided Engineering Pub Date : 2024-10-24 DOI: 10.1155/2024/2690885

Rui Tian, Hao Wu, Mai Lu

{"title":"Study of Electromagnetic Radiation From High-Speed Train Voice and Data Antennae on the Health of Pacemaker Wearers","authors":"Rui Tian, Hao Wu, Mai Lu","doi":"10.1155/2024/2690885","DOIUrl":"https://doi.org/10.1155/2024/2690885","url":null,"abstract":"In China, high-speed trains have become a major means of transportation for the masses. When the passengers wearing pacemakers travel on high-speed trains, electromagnetic environment in the carriage where the GSM-R voice and data antennae are located should be concerned. In this work, a real-size carriage monopole antennae simulating voice and data antennae as high-frequency radiation sources and wearing pacemaker passenger’ models were established to study the electromagnetic exposure of the passenger at different conditions. The results showed that when the passenger faced the voice antenna, he suffered much greater electromagnetic radiation than when his back in turned from it. The electric field strength, average SAR, and temperature rise of the heart when facing the antenna were 27.3 V/m, 0.0102 W/kg, and 0.0016°C, respectively. Meanwhile, the temperature rise of the pacemaker was 0.001°C. We also obtained the values of electromagnetic dose for the whole body. All data were below the limits of the ICNIRP guidelines. These results indicate that the electromagnetic fields generated by the GSM-R voice and data antennae do not harm the health of passengers wearing pacemaker.","PeriodicalId":54944,"journal":{"name":"International Journal of RF and Microwave Computer-Aided Engineering","volume":"2024 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2024/2690885","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142525018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Miniaturize Dual-Band Open-Loop Resonator-Based MIMO Antenna With Wide Bandwidth and High Gain 基于开环谐振器的宽带高增益微型化双频 MIMO 天线

IF 0.9 4区工程技术

International Journal of RF and Microwave Computer-Aided Engineering Pub Date : 2024-10-16 DOI: 10.1155/2024/3858416

Ming-An Chung, Chia-Wei Lin, Chih-Wei Yang

{"title":"Miniaturize Dual-Band Open-Loop Resonator-Based MIMO Antenna With Wide Bandwidth and High Gain","authors":"Ming-An Chung, Chia-Wei Lin, Chih-Wei Yang","doi":"10.1155/2024/3858416","DOIUrl":"https://doi.org/10.1155/2024/3858416","url":null,"abstract":"This paper proposes and analyzes a 2 × 2 multi-input multioutput antenna based on an open-loop resonator structure and an inverted L structure. The top layer of the antenna uses symmetric inverted hook-shaped and inverted L branches and is connected to the bottom layer of the dual-feed port and the ground plane using the VIAs, respectively. The open-loop resonator structure at the bottom of the antenna and the top layer of the branched circuit are resonated to provide wide-bandwidth and dual-frequency characteristics. The substrate uses FR4 with an area of 40 × 30 × 0.8 mm3. Although the two antenna feed ports are very close to each other, using via to connect the defective bottom ground structure and the top inverted L-shaped branch, the isolation still achieves an excellent performance of 15 dB. The antenna has multiband application characteristics, and the bands include 2.29–5.51, 6.14–10.26, 2.29–5.33, 5.19–6.64, and 6.78–10.16 GHz. In pattern and MIMO transmission efficiency measurement, the peak radiation efficiency is 89%, the peak gain is 8.5 dBi, and the ECC is less than 0.034. In the transmission efficiency measurement mode using 64-QAM, watching the error vector magnitude at 2.56 and 5.11 GHz, the demodulation effect is very good, and the respective throughput results are 100% and 79.2%. The broadband characteristics of the antenna have a variety of applications, and it is simulated at the specific absorption rate, which meets the standards set by the Federal Communications Commission and is very suitable for use in wearable devices. The antenna can be applied to the X-band, n77, n79, Sub-6 GHz, WiMax, DSRC, WiFi 6, WiFi 6E, WiFi 7, C-V2X, and C-band.","PeriodicalId":54944,"journal":{"name":"International Journal of RF and Microwave Computer-Aided Engineering","volume":"2024 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2024/3858416","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142443521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multifunctional Frequency-Selective Rasorber With Passband Stealth Performance 具有通带隐形性能的多功能选频干扰器

IF 0.9 4区工程技术

International Journal of RF and Microwave Computer-Aided Engineering Pub Date : 2024-10-12 DOI: 10.1155/2024/3699905

Kun Liao, Zhiming Liu

{"title":"Multifunctional Frequency-Selective Rasorber With Passband Stealth Performance","authors":"Kun Liao, Zhiming Liu","doi":"10.1155/2024/3699905","DOIUrl":"https://doi.org/10.1155/2024/3699905","url":null,"abstract":"A multifunctional frequency-selective rasorber (MFSR) with passband stealth performance by using PIN diodes is investigated, which is made up of two reconfigurable components (a lossy layer and transmissive polarization converter surface (lossless layer)). The proposed MFSR shows transmission in-band and absorption out-band at working state, but the transparent window is closed to achieve full-band stealth at nonworking state. Besides, the equivalent circuit model (ECM) is constructed to annotate the operating principle of the designed MFSR. The MFSR indicates a wide cross-polarized transmission window from 3.71 to 4.38 GHz between two absorption bands at working, meanwhile a broadband copolarized reflection band (S11 < −10 dB) is accomplished in 1.78–5.50 GHz. At nonworking, an ultra-wideband stealth band is realized in 1.81–7.0 GHz when the absorptivity is over 80%, which has a 117.8% fractional bandwidth (FBW). In addition, the MFSR has a stable oblique incident characteristic (up to 25°). Finally, the sample of the MFSR is manufactured and experimented to demonstrate the availability of this design.","PeriodicalId":54944,"journal":{"name":"International Journal of RF and Microwave Computer-Aided Engineering","volume":"2024 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2024/3699905","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142429922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Frequency Domain UWB Channel Characterization and Modeling in Indoor Static Environment 室内静态环境中的频域 UWB 信道特性分析与建模

IF 0.9 4区工程技术

International Journal of RF and Microwave Computer-Aided Engineering Pub Date : 2024-10-01 DOI: 10.1155/2024/3742665

Joydeep Pal, Bhaskar Gupta

{"title":"Frequency Domain UWB Channel Characterization and Modeling in Indoor Static Environment","authors":"Joydeep Pal, Bhaskar Gupta","doi":"10.1155/2024/3742665","DOIUrl":"https://doi.org/10.1155/2024/3742665","url":null,"abstract":"In this article, distance and frequency-dependent indoor wireless channel characterization and modeling are presented in C, X, and Ku bands at the line of sight (LOS) and nonline of sight (nLOS) scenarios. Complex frequency responses of the indoor radio channel are measured using the frequency-domain approach. The terminal and measurement setup dependencies of the propagation channel are deconvoluted using closed-form expressions devised from a two-port network model approach of the antenna transreceiver system. Subsequently, terminal independent frequency-domain channel transfer functions (CTFs) and time-domain channel impulse responses (CIRs) are derived for accurate statistical analysis of large- and small-scale fading parameters of the propagation channel. A distance-dependent statistical pathloss model is proposed. Successively, a frequency domain channel model using the fifth-order autoregressive process is proposed. Subsequently, the existence of the multiple clusters in the environment is analyzed by the poles of the transfer functions of the model. Models are validated in both time and frequency domains by comparing the computer-simulated synthetic model data with the empirical channel responses. The measurement data and the model data are seen to be in good agreement.","PeriodicalId":54944,"journal":{"name":"International Journal of RF and Microwave Computer-Aided Engineering","volume":"2024 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2024/3742665","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A 10 × 10 MIMO Multiband Broadband Planar Antenna for Multiband Applications 用于多频带应用的 10 × 10 MIMO 多频带宽平面天线

IF 0.9 4区工程技术

International Journal of RF and Microwave Computer-Aided Engineering Pub Date : 2024-10-01 DOI: 10.1155/2024/4839224

Ming-An Chung, Chia-Wei Lin, Ing-Peng Meiy

{"title":"A 10 × 10 MIMO Multiband Broadband Planar Antenna for Multiband Applications","authors":"Ming-An Chung, Chia-Wei Lin, Ing-Peng Meiy","doi":"10.1155/2024/4839224","DOIUrl":"https://doi.org/10.1155/2024/4839224","url":null,"abstract":"This paper proposes a 10 × 10 MIMO multiband broadband planar antenna for tablets or laptops. The designed antennas cover a large number of the popular sub-6-GHz application bands, such as 0.617–0.96, 2.1–2.7, 3.5–4.5, and 6.1–7.2 GHz for public safety communications, radio systems, Bluetooth, Wi-Fi, and satellite communications. The proposed antenna is designed with grounded branches, which can generate a wide bandwidth and cover most of the sub-6-GHz application band by coupling between branches of different lengths and antennas. MIMO antennas have been measured to have an envelope correlation coefficient of less than 0.7 and have met the standards set by international organizations for human radiation absorption simulations. The proposed antenna validates the unique 10 × 10 MIMO antenna structure and feasibility. Multiple operable frequency bands are realized, and the radiation effect of the antenna on the human body is analyzed if it complies with international market standards. The proposed antenna design is well suited for multiband and broadband requirements.","PeriodicalId":54944,"journal":{"name":"International Journal of RF and Microwave Computer-Aided Engineering","volume":"2024 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2024/4839224","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Low-Cost Low-Loss Tunable Dual-Band Filter Using Coupled Lines With Variable Coupling Coefficients 使用耦合系数可变的耦合线的低成本低损耗可调双频滤波器

IF 0.9 4区工程技术

International Journal of RF and Microwave Computer-Aided Engineering Pub Date : 2024-09-26 DOI: 10.1155/2024/5668593

Wang Qunliang, Jiang Yanfeng, Wang Yanxiong

引用次数: 0