检索结果-内蒙古大学图书馆

2022 29th International Conference on Nuclear Engineering, ICONE 2022

作者： Li, Lintai Zhou, Yanmin Li, Yuanyuan Sun, Zhongning Wang, Yin Gu, Haifeng Ma, Song Heilongjiang Provincial Key Laboratory of Nuclear Power System & Equipment Harbin Engineering University Harbin150001 China Fundamental Science on Nuclear Safety and Simulation Technology Laboratory Harbin Engineering University Harbin150001 China China Nuclear Power Engineering Co. Ltd Beijing100005 China

ISBN: (纸本)9780791886502

As a new filter material, metal fiber has good high-temperature resistance, moisture resistance, and radiation resistance. To explore the influence of the fiber's primary structural parameters on the fiber's performance, this paper experimentally studied the relationship between the flow resistance, filtration efficiency, and dust holding capacity of the metal fiber filter material and the thickness and solid volume fraction (SVF). Under the condition of ensuring uniform deposition of NaCl aerosol, we found that the deposition law of NaCl polydisperse aerosol is the same as that of monodisperse aerosol. The results show that for the same fiber diameter, increasing the fiber's thickness and SVF will increase the flow resistance of the fiber under the same dust holding capacity;that is, reducing the dust holding capacity of the fiber. In the depth filtration, the efficiency increases rapidly due to the aerosol deposition in the fiber, while the efficiency changes gently when the filter cake is covered on the filtration surface. At the same time, for each high filtration efficiency fiber, the variation characteristics of resistance with dust holding capacity in the deep filtration stage are the same. After the filter cake is completely covered on the filter surface, the growth trend of resistance is the same, independent of the fiber's structural parameters. © 2022 by ASME.

关键词： Fibers

来源：评论

学校读者我要写书评

暂无评论

Cross-Polarization suppression by Comb-Shaped slots in Microstrip Patch 13

Cross-Polarization suppression by Comb-Shaped slots in Micro...

引用

13th International Conference on Microwave and Millimeter Wave technology, ICMMT 2021

作者： Ma, Jing Tan, Shi-Li Ni, Si-Yuan Wang, Chen Sun, Kai Luo, Yong-Yuan Peng, Lin Beijing Simulation Center Science And Technology On Special System Simulation Laboratory Beijing100854 China 95972 Troops Of PLA Jiuquan735018 China Guilin University Of Electronic Technology Guangxi Key Laboratory Of Wireless Wideband Communication And Signal Processing Guangxi Guilin541004 China

ISBN: (纸本)9781665434379

Cross-polarization (XP) of the microstrip antenna was suppressed by etching comb-shaped slots in the patch. By cutting longitudinal comb-shaped slots on the rectangular patch, the transverse current at the patch edges that lead to cross-polarization was dammed up. Then, the co-to cross-polarization (CP-XP) ratio over entire angular range around the broadside direction was increased from 20 dB of the rectangular microstrip antenna (RMA) to 35 dB of the defected patch structure (DPS). Moreover, as the longitudinal current was little affected by the slots, the proposed structure has little effect on the other performances of the antenna (including gain, directivity, radiant principle and impedance bandwidth). As the presented structure is achieved by simple adding slots to the rectangular patch, it is very easy to be fabricated. © 2021 IEEE.

关键词： Etching

来源：评论

学校读者我要写书评

暂无评论

Prediction of Hybrid Asynchronous Frequency Hopping Pattern based on Deep Learning in Wideband Spectrum

Prediction of Hybrid Asynchronous Frequency Hopping Pattern ...

引用

Chinese Automation Congress (CAC)

作者： Ya Wang Jiaqi Wang Shuai Yuan Naijin Liu Yuanming Lu Qian Xuesen Laboratory of Space Technology China Academy of Space Technology Beijing China Science and Technology on Complex System Control and Intelligent Agent Cooperation Laboratory Beijing Electro-Mechanical Engineering Institute Beijing China Unit 63893 of PLA Luoyang China

In non-cooperative scenarios, wideband frequency hopping (FH) communication reconnaissance including FH signal detection, parameter estimation, and network sorting under single-channel reception is challenging. The FH pattern contains the most information about FH signals. So it is the core of FH parameter estimation. Based on the task analysis, this paper proposes a blind prediction framework combining deep learning (DL) and clustering methods to improve the accuracy and efficiency of FH pattern estimation for mixed signals in the wideband spectrum. The unique advantage of this framework is that it requires no prior signal information and anchors but exploits the inherent time-frequency (TF) properties of asynchronous FH signals. It has a strong generalization ability and can adapt to signals of any shape. Moreover, a new comprehensive evaluation metric, normalized root mean square error including missed detection (NRMSE-MD), suitable for sequence data prediction is proposed to evaluate the level of missed detection and false detection in signal monitoring. Experimental results demonstrate the superiority of the proposed framework and the effectiveness of the proposed evaluation metric.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Facile synthesis of ironenickelecobalt ternary oxide(FNCO)mesoporous nanowires as electrode material for supercapacitor application

引用

Journal of Materiomics 2022年第1期8卷 221-228页

作者： Muhammad Usman Muhammad Tayyab Ahsan Sofia Javed Zeeshan Ali Yiqiang Zhan Irfan Ahmed Sajid Butt Mohammad Islam Asif Mahmood M.Aftab Akram School of Chemical and Materials Engineering National University of Sciences and Technology(NUST)Sector H-12Islamabad44000Pakistan Department of Materials Science and Engineering College of EngineeringPeking University100871BeijingChina State Key Laboratory of ASIC and System Center of Micro-Nano SystemSISTFudan UniversityShanghai200433China Department of Materials Science and Engineering Institute of Space TechnologyIslamabad44000Pakistan New Mexcico Institute of Mining&Technology SocorroNM 87801USA School of Chemical and Biomolecular Engineering The University of Sydney2006SydneyAustralia

Transition Metal Oxides have drawn significant attention due to their reversible chemical redox reaction and long-life *** agglomeration and shrinkage/expansion of transition metal oxides in the nanosize regime have a noticeable effect on their electrochemical *** in this work,mesoporous nanowires(NWs)with a typical composition of iron-nickel-cobalt ternary oxide(FNCO)are synthesized using a simple,facile and cost-effective hydrothermal process followed by furnace *** NWs are then extensively investigated as an electrode material for supercapacitor *** compare the electrochemical properties,nanowires of nickel-cobalt oxide(NCO),iron-cobalt oxide(FCO)and cobalt oxide(CO)were also produced by following the same *** FNCO NWs are found to overcome the shortcomings in the electrochemical energy storage devices by exhibiting higher values of specific capacitance(2197 Fg^(-1))and energy density(109 Whkg^(-1))at 1 Ag^(-1) current ***,the FNCO NWs also showed a cyclic charge/discharge stability of 96%even up to 20,000 ***,a FNCO//graphene asymmetric device,fabricated with FNCO NWs and graphene as positive and negative electrodes,respectively,which exhibit high energy density(47 Whkg^(-1)),power density(375 Wkg^(-1))and excellent capacitance retention(86%)after 15,000 cycles.

关键词： Electrochemistry Hydrothermal synthesis Nanowires Supercapacitor Transition metal oxides

来源：评论

学校读者我要写书评

暂无评论

Thermal Design of Active Phased Array Antenna for GEO Communication Satellite Based on Structure and Thermal Control Integration Method 8th

Thermal Design of Active Phased Array Antenna for GEO Commun...

引用

8th Asia International Symposium on Mechatronics, AISM 2021

作者： Yang, Shuanggen Cheng, Wenlong Wang, Lu Zhao, Rui Ning, Bo Deng, Qi Department of Thermal Science and Energy Engineering University of Science and Technology of China Hefei230027 China East China Research Institute of Electronic Engineering Hefei230031 China Beijing Key Laboratory of Space Thermal Control Technology Beijing Institute of Spacecraft System Engineering Beijing100094 China

ISBN: (纸本)9789811913082

With the further development of space communication satellite payload technology, the demand for active phased array antenna (APAA) is increasing, and heat dissipation is a key technical problem affecting the performance of APAA. In order to ensure an ideal temperature range and reduce temperature difference in orbit, a thermal design method of a high power APAA of GEO communication satellite is proposed. The heat pipes are embedded in the active satellite installing plate to solve the heat collection, uniformly distributing temperature and heat transfer, and the active satellite installing plate is not only the structural support of the antenna but also the cooling plate of the antenna. The heat of APAA is taken away by integrated thermal coupling with the satellite platform, which is exchanged between both sides of the active satellite installing plate and the cold plate based liquid cooling, and afterwards is transmitted to the thermal radiators of satellite through single-phased fluid loop. The simulation analysis results show that the temperature and the temperature difference of the APAA meet the requirements of thermal reliability and design performance. The thermal control method used provides a feasible design reference for the thermal design of similar GEO orbit communication satellite APAA. © 2022, science Press.

关键词： Heat pipes

来源：评论

学校读者我要写书评

暂无评论

Design and Analysis of Terminal Guidance Law for Kinetic Interceptors based on Pulse Engine

引用

Journal of Electronic Research and Application 2024年第5期8卷 95-108页

作者： Shixin Li Jia Ma Shuai Yue School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094China Aerospace System Engineering Shanghai Shanghai 201100China Shanghai Key Laboratory of Spacecraft Mechanism Shanghai 201108China National Key Laboratory of Space Intelligent Control Beijing 100048China

A new terminal guidance law is proposed based on a solid propellant pulse engine and an improved proportional navigation method to address the terminal guidance issue for kinetic *** this basis,the start-stop curve of the pulse motor during the terminal guidance process is designed,along with its start-up *** effectiveness of the proposed guidance strategy is verified through simulation.

关键词： Pulse engine Terminal guidance law Kinetic interceptor Proportional navigation method

来源：评论

学校读者我要写书评

暂无评论

A 2D post-processing method for resolution enhancement of coherent wind lidar 15

A 2D post-processing method for resolution enhancement of co...

引用

15th International Conference on Information Optics and Photonics, CIOP 2024

作者： Zhao, Yue Zhang, Yunpeng Zhu, Xiaopeng Bi, Decang Liu, Jiqiao Chen, Weibiao Wangzhijiang Innovation Center for Laser Aerospace Laser Technology and System Department Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai201800 China Key Laboratory of Space Laser Communication and Detection Technology Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai201800 China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences Beijing100049 China

ISBN: (数字)9781510686175

ISBN: (纸本)9781510686168

Based on the time-domain simulation model of coherent wind measurement, it is deduced that the detected atmospheric backscattered spectrum is a two-dimensional convolution of the real atmospheric information and the instrument point spread function. The spatial resolution can be improved by applying the image deconvolution algorithm to the inversion of the coherent wind lidar (CWL) signal. The effect of the deconvolution algorithm in improving spatial resolution is compared in simulation and experiment. The results show that the spatial resolution can be improved effectively by using the deconvolution algorithm when the transmitted pulse waveform is known. © 2024 SPIE.

关键词： Optical transfer function

来源：评论

学校读者我要写书评

暂无评论

Low-Earth Orbital Lifetime Prediction Based on Parameter Sensitivity Analysis and Deep Learning

引用

IEEE Transactions on Aerospace and Electronic systems 2025年

作者： Chen, Shun-Yi Yang, Zhen Wang, Hua Lu, Lin State Key Laboratory of Space System Operation and Control Changsha410073 China National University of Defense Technology College of Aerospace Science and Engineering Changsha410073 China China Astronaut Research and Training Center Beijing100094 China

This article proposes an intelligent prediction method for the orbital lifetime of resident space objects (RSOs) in low Earth orbit. This method is intended to satisfy the computational efficiency and accuracy requirements when predicting the large-scale RSOs. It helps to analyze the distribution and uncertainty of RSOs' lifetime. First, based on the semi-analytical orbit prediction model, a parameter sensitivity analysis method for the orbital lifetime is proposed, and the parameters that affect the orbital lifetime are investigated. Second, using a fully connected neural network, an orbital lifetime prediction model is established based on deep learning. The hyperparameters of the deep learning model are optimized using the black-winged kite algorithm. Finally, by combining the sensitivity analysis with the deep learning model, an intelligent prediction method is proposed for the rapid prediction of orbital lifetime. simulation results show that the proposed intelligent prediction method accurately determines the orbital lifetime of RSOs and has higher prediction efficiency than the traditional prediction method. The research results provide an effective calculation and analysis tool for predicting the orbital lifetime of large-scale RSOs in the future. © 2025 IEEE.

关键词： Prediction models

来源：评论

学校读者我要写书评

暂无评论

Large Eddy simulation of Flow and Heat Transfer Performance in Periodically Inward Corrugated Tubes

SSRN

引用

SSRN 2023年

作者： Zhong, Yuzhou Song, Yueheng Zhao, Lei Mi, Fei Zhao, Jingquan Zhu, Xiaowei School of Aeronautic Science and Engineering Beihang University Beijing100191 China Science & Technology on Complex Aviation System Simulation Laboratory Beijing100070 China Co. Ltd. Henan453049 China

Corrugated tubes are extensively unitized in enhancing heat transfer within tubular heat exchange devices. The efficiency of these corrugated tubes is closely linked to the geometric characteristics of the surface corrugations. In this study, we conducted an extensive series of Large Eddy simulations on a representative type of enhanced tube featuring periodic inward corrugations (PIC). Our goal was to compile a comprehensive and precise dataset of the thermal and hydraulic properties specific to this design. The key design parameters that define the corrugated patterns are corrugation height, corrugation width, and the length of the straight section. We systematically explored these parameters to understand their impact on heat transfer and fluid dynamics. Among these parameters, corrugation height has been identified as the most influential factor affecting flow and heat transfer properties. As the corrugation height varies from 1/8D to 3/8D, we observed a substantial increase in the friction factor and Nusselt number by a factor of 209 and 5, respectively, at Re = 1000;while the critical Reynolds number decreased roughly from 800 to 100. These findings underscore the significant role of corrugation height in shaping the flow and heat transfer performance of PIC tubes. The other two parameters, corrugation width and straight section length, were also found to be crucial in determining the overall heat transfer coefficient and pressure drop. The results of our study suggest that when utilizing this type of corrugated tubes, careful consideration is required to strike an optimal balance between heat transfer efficiency and pressure loss. The large-sets LES results presented in this paper can serve as valuable inputs for optimizing the design of PIC tubes. © 2023, The Authors. All rights reserved.

关键词： Large eddy simulation

来源：评论

学校读者我要写书评

暂无评论

On-board Time-varying Topology Self Prediction Routing Network Communication technology 15

On-board Time-varying Topology Self Prediction Routing Netwo...

引用

15th IEEE International Conference on Advanced Infocomm technology, ICAIT 2023

作者： Yu, Jiyang Huang, Dan Wu, Nan Li, Jinyang Li, Wenjie Wang, Xianjie Beijing Institute of Spacecraft System Engineering China Academy of Space Technology Beijing China Chongqing University of Technology China Research & Development Academy of Machinery Equipment Chongqing China Fangzhou Key Technology Laboratory Beijing Institute of Computer Technology and Applications Beijing China Chongqing Feima Innovation Research Institute Beijing Blackstone Matrix Technology Co. Ltd Chongqing China Chongqing University of Technology College of Computer Science and Engineering Chongqing China

ISBN: (纸本)9798350314120

Facing the difficulties of large-scale networked satellite communication, such as unstable topology, diversified channel types, and uncertain satellite link failure, this paper proposes a general optimal routing path calculation method based on historical data prediction, and establishes a Statistical model based on historical data prediction for inter satellite communication transmission, which is not limited to transient failures caused by aging energy, storage, and load. At the same time, in the process of calculating the transmission rate and packet loss rate of the communication link, historical data is introduced to form a channel rate function that changes over time, which is used to achieve communication prediction within the transmission time and achieve self-sensing of the communication link's state. Based on the self-prediction state of the communication link, combined with the domain search algorithm, the maximum probability optimal solution of the long-term interactive routing process is considered to achieve real-time optimal solution for data transmission in the constellation of Jupiter in orbit. A simulation verification was conducted for a large number of randomly distributed routing applications in a short period of time, and parameters such as link stability, load capacity, and business time delay were compared with previous designs. The results show that the proposed method has good stability, which is more than 10% higher than previous designs;The link load is significantly lower compared to previous designs;Under the condition of a large number of routing applications, the service delay has been reduced by 27% compared to previous designs, ensuring routing communication under the time-varying topology of the constellation group. © 2023 IEEE.

关键词： Time delay

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：