检索结果-内蒙古大学图书馆

Effects of Geometric Parameters on Performance of Rectangular Submerged Inlet for Aircraft

Transactions of Nanjing University of Aeronautics and Astronautics 2021年第6期38卷 984-992页

作者： LIU Chao PEI Houju CHEN Changdong XU Wenbing YANG Kaijie Environment Control and Oxygen System Department Shanghai Aircraft Design and Research InstituteShanghai 201210P.R.China AVIC Nanjing Servo Control System Corporation Nanjing 210016P.R.China College of Energy&Power Engineering Jiangsu University of Science and TechnologyZhenjiang 212003P.R.China Key Laboratory of Aircraft Environment Control and Life Support MIITNanjing University of Aeronautics and AstronauticsNanjing 210016P.R.China

To improve the comfortability and safety of aircraft,the demand of rectangular submerged inlets(RSIs)with low resistance is proposed to increase the inlet flow rate of ram air. A theoretical model is built to numerically analyze the effects of geometric parameters on the inlet mass flow rate of RSIs. The geometric parameters in question here encompass the aspect ratio of 2—4,the ramp angle of 6°—7°,the characteristic parameter of the throat of 0.20 —0.30,the ramp length of 939—1 337 mm,and the cone angle of 0° —3°. Simulation results demonstrate that the mass flow rate(MFR)is positively correlated with the aspect ratio,ramp angle,ramp length,and cone angle,and negatively correlated with characteristic parameter of the throat. Within the range of the geometric parameters considered,the RSI with the aspect ratio of 3,the ramp angle of 6°,the characteristic parameter of the throat of 0.20,the ramp length of 1 337 mm,and the cone angle of 3° obtains the largest MFR value of about 2.251 kg/s.

关键词： ram air system rectangular submerged inlet geometric parameter mass flow rate(MFR)

来源：评论

学校读者我要写书评

暂无评论

Disjoint-Path and Golden-Pin Based Irregular PCB Routing with Complex Constraints

Disjoint-Path and Golden-Pin Based Irregular PCB Routing wit...

引用

design Automation Conference

作者： Qinghai Liu Qinfei Tang Jiarui Chen Chuandong Chen Ziran Zhu Huan He Jianli Chen Yao-Wen Chang Center for Discrete Mathematics Fuzhou University Fuzhou China Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou China College of Computer and Date Science Fuzhou University Fuzhou China Department of Microelectronics Fuzhou University Fuzhou China Department of Microelectronics Southeast University Nanjing China Hangzhou Huawei Enterprises Telecommunication Technologies Co. Ltd Hangzhou China State Key Lab of ASIC & System Fudan University Shanghai China Graduate Institute of Electronics Engineering National Taiwan University Taipei Taiwan Department of Electrical Engineering National Taiwan University Taipei Taiwan

PCB routing becomes time-consuming as the complexity of PCB design increases. Unlike traditional schemes that treat the two essential PCB routing processes separately, namely, escape and bus routing, we consider the continuity between them and present a golden-pin-based routing scheme to find the desired solution with angle and topology constraints. Further, conventional rip-up and reroute methods are often ineffective and inefficient for congestion alleviation and routability optimization. We construct a component graph by modeling components as vertices and applying the minimum weight vertex covering method to improve the routability. A self-adaptable ordering method is presented for escape routing to arrange the pin order on the component boundary, guaranteeing successful bus routing. In addition, escape routing is performed based on a disjoint path method. We construct a dynamic Hanan grid in bus routing and utilize a novel congestion adjustment technique to improve solution quality. Compared with FreeRouting and Allegro, the experiment results show that our algorithm achieves high routability and a significant 90% runtime reduction.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Formal verification of 5G-EAP-TLS authentication protocol 4

Formal verification of 5G-EAP-TLS authentication protocol

引用

4th IEEE International Conference on Data science in Cyberspace, DSC 2019

作者： Zhang, Jingjing Wang, Qiang Yang, Lin Feng, Tao Army Engineering University of PLA Nanjing China National Key Laboratory of Science and Technology on Information System Security Beijing China

ISBN: (纸本)9781728145280

In mobile communication networks, the security of users' data depends on the guarantees provided by the authentication protocols. For the next generation of mobile network (i.e., 5G network), the 5G-EAP-TLS protocol has been proposed for this purpose. However, it is still unknown whether this protocol provides the claimed security guarantees or not. To fill this gap, we provide in this work the first formal model of 5G-EAP-TLS protocol and conduct a thorough analysis based on Scyther model checker. Secondly, we identify several design flaws in the protocol, which may jeopardize the security goals and result in severe security vulnerabilities when implemented in real systems. To our knowledge, this is the first study on the formal verification of 5G-EAP-TLS protocol. © 2019 IEEE.

关键词： Model checking

来源：评论

学校读者我要写书评

暂无评论

Delving into the Continuous Domain Adaptation

arXiv

引用

arXiv 2022年

作者： Xu, Yinsong Jiang, Zhuqing Men, Aidong Liu, Yang Chen, Qingchao School of Artificial Intelligence Beijing University of Posts and Telecommunications National Institute of Health Data Science Peking University Beijing China School of Artificial Intelligence Beijing University of Posts and Telecommunications Beijing Key Laboratory of Network System and Network Culture Beijing China School of Artificial Intelligence Beijing University of Posts and Telecommunications Beijing China Wangxuan Institute of Computer Technology Peking University Beijing China National Institute of Health Data Science Peking University Beijing China

Existing domain adaptation methods assume that domain discrepancies are caused by a few discrete attributes and variations, e.g., art, real, painting, quickdraw, etc. We argue that this is not realistic as it is implausible to define the real-world datasets using a few discrete attributes. Therefore, we propose to investigate a new problem namely the Continuous Domain Adaptation (CDA) through the lens where infinite domains are formed by continuously varying attributes. Leveraging knowledge of two labeled source domains and several observed unlabeled target domains data, the objective of CDA is to learn a generalized model for whole data distribution with the continuous attribute. Besides the contributions of formulating a new problem, we also propose a novel approach as a strong CDA baseline. To be specific, firstly we propose a novel alternating training strategy to reduce discrepancies among multiple domains meanwhile generalize to unseen target domains. Secondly, we propose a continuity constraint when estimating the cross-domain divergence measurement. Finally, to decouple the discrepancy from the mini-batch size, we design a domain-specific queue to maintain the global view of the source domain that further boosts the adaptation performances. Our method is proven to achieve the state-of-the-art in CDA problem using extensive experiments. The code is available at https://***/SPIresearch/CDA. Copyright © 2022, The Authors. All rights reserved.

关键词： Knowledge management

来源：评论

学校读者我要写书评

暂无评论

An iterative method for the solution of equilibrium position in the shaft-hole assembly based on spring contact model 8

An iterative method for the solution of equilibrium position...

引用

8th CIRP Conference of Assembly technology and systems, CATS 2020

作者： Zhang, Yuanyang Guo, Junkang Gao, Xianming Hong, Jun School of Mechanical Engineering Xi'An Jiaotong University Xi'an Shaanxi710049 China Key Laboratory for Modern Design and Rotor-Bearing System Ministry of Education Xi'An Jiaotong University Xi'an Shaanxi710049 China College of Mechanical and Electrical Engineering Shaanxi University of Science and Technology Xi'an710021 China

The traditional finite element method has the advantages of strong versatility and high calculation accuracy. Thus it is widely applied in various numerical simulation problems. Although the traditional finite element method for solving the shaft-hole assembly problem can obtain better solution accuracy, the process of modeling and calculation take a long time and thus cannot meet the engineering application requirements when the equilibrium position after the assembly needs to be obtained quickly to guide the subsequent process. In this paper, an iterative method based on the spring contact model is proposed. Firstly, the actual form error of the shaft and hole is characterized by the Fourier series expansion method;Then, in the contact surface, we established a discrete spring contact model and obtained the equivalent stiffness of the coupling spring through the discrete solid model. The balance iterative calculation based on the form errors and contact deformation force can finally determine the equilibrium position after the assembly. Compared with the calculation results of the finite element model, the equilibrium position of the shaft-hole assembly can be quickly solved under the condition of sacrificing certain precision. From this aspect it can be estimated that this method has a good potential for engineering application. © 2020 The Author(s).

关键词： Assembly

来源：评论

学校读者我要写书评

暂无评论

Construction of a CRISPR-based paired-sgRNA library for chromosomal deletion of long non-coding RNAs

引用

Quantitative Biology 2020年第1期8卷 31-42页

作者： Minzhen Tao Qiaochu Mu Yurui Zhang Zhen Xie MOE Key Laboratory of Bioinformatics and Bioinformatics Division Center for Synthetic and System BiologyDepartment of AutomationBeijing National Research Center for Information Science and TechnologyTsinghua UniversityBeijing 100084China Zhejiang Tmall Techonogy Co. LtdYuhang DistrictHangzhou 311121China Beiing Syngentech Co..Ltd Zhongguancun Life Science ParkChangping DistrictBeijing 102206China

Background:Derived from an adaptive bacterial immune system,the clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated 9(Cas9)system has shown great potential in high-throughput functional genomic screening,especially for protein-coding ***,it is still challenging to apply the similar strategy to study non-coding genomic elements such as long non-coding RNAs(lncRNAs)or clusters of microRNAs,because short insertions or deletions may not be sufficient to generate loss-of-function ***:Here,we presented a systematic strategy for designing a CRISPR-based paired-sgRNA library for highthroughput screening in non-coding *** to the abundance of lncRNAs and their diverse regulatory roles in vivo,we repurposed microarray datasets to select 600 highly expressed lncRNAs in non-small-cell lung cancer and designed two schemes for lncRNA deletion with^20 paired-sgRNAs for each *** Golden-Gate assembly,we generated a pooled CRISPR-based library with a total of 12,878 sgRNA ***:Over 80%of paired-sgRNAs were recovered from final pooled library with a relarively even *** efficiency of sgRNA pairs was validated through experiments of transient transfection and viral ***,randomly selected paired-sgRNAs showed that efficient deletion of genomic DNA could be achieved with a deletion size within the range of 500 to 3000 ***:In summary,we have demonstrated a strategy to design and construct a pooled paired-sgRNA library to generate genomic deletion in the lncRNA regions,validated their deletion efficiency and explored the relationship of deletion efficiency with respect to deletion *** method would be also suitable for investigation of other uncharacterized non-coding genomic regions in mammalian cells in an efficient and cost-efTective manner.

关键词： CRISPR/Cas9 paired-sgRNA chromosomal deletion non-coding genomic elements lncRNA

来源：评论

学校读者我要写书评

暂无评论

Interfacial area correlation for annular flow in vertical pipes 27

Interfacial area correlation for annular flow in vertical pi...

引用

27th International Conference on Nuclear Engineering: Nuclear Power Saves the World!, ICONE 2019

作者： Liu, Hang Huang, Haojie Lai, Jianyong Pan, Liangming Li, Yi Zhou, Wenxiong Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610041 China Nanjing Research Institute of El ectronics Technology Nanjing210000 China Department of Nuclear Engineering Chongqing University Chongqing400044 China

ISBN: (纸本)9784888983051

Interfacial area concentration is one of the most critical parameters in two-phase flow and reflects the interfacial area of mass, momentum and energy transfer. The prediction of interfacial area concentration is also essential to close the interfacial transfer terms in the two-fluid model. The calculation of interfacial area concentration has been well developed from bubbly flow to churn flow, including interfacial area correlations and two-group interfacial area transport equation. While seldom researchers focus on that for annular flow or annular mist flow. This paper proposed the one-dimensional interfacial area correlation for annular flow in vertical pipes based on the averaged liquid film thickness model for annular flow. The effects of the droplets in pipes were also considered in the model. The new model has been evaluated against the existing experimental data. The results indicate that the new model can provide the excellent prediction of the interfacial area concentration for annular flow in vertical pipes. Copyright © 2018-2019 by JSME

关键词： Two phase flow

来源：评论

学校读者我要写书评

暂无评论

Effect of finned structure on critical heat flux (CHF) in downward-face pool boiling 27

Effect of finned structure on critical heat flux (CHF) in do...

引用

27th International Conference on Nuclear Engineering: Nuclear Power Saves the World!, ICONE 2019

作者： Wang, Kai Erkan, Nejdet Cai, Rong Okamoto, Koji Department of Nuclear Engineering and Management School of Engineering University of Tokyo Tokyo Japan Science and Technology on Reactor System Design Technology Laboratory Chengdu China Nuclear Professional School School of Engineering University of Tokyo Tokyo Japan

ISBN: (纸本)9784888983051

CHF plays an important role in the heat transfer process during the external reactor vessel cooling (IVR-ERVC) which is deemed as a very effective way to release the decay heat after the core melted. In this paper, the experiment of the macro-fin structure experiment positioned on slope that is declined at angles of 5°and 10°was done. The results of the copper bar experiment were then analyzed and compared with the results obtained from a copper block experiment that had been conducted previously at the same test facility, and it was found that the CHF decreased. Finally, the hot/dry spot theory for the copper bar was brought up in an attempt to explain the difference of copper and copper bar. It seemed that using this theory can explain the decrease of CHF for copper bar. Copyright © 2018-2019 by JSME

关键词： Heat flux

来源：评论

学校读者我要写书评

暂无评论

Reconfigurable Intelligent Surface Assisted High-Speed Train Communications: Coverage Performance Analysis and Placement Optimization

arXiv

引用

arXiv 2023年

作者： Liu, Changzhu He, Ruisi Niu, Yong Han, Zhu Ai, Bo Gao, Meilin Ma, Zhangfeng Wang, Gongpu Zhong, Zhangdui The State Key Laboratory of Advanced Rail Autonomous Operation The School of Electronics and Information Engineering The Frontiers Science Center for Smart High-speed Railway System The Beijing Engineering Research Center of High-Speed Railway Broadband Mobile Communications Beijing Jiaotong University Beijing100044 China The State Key Laboratory of Advanced Rail Autonomous Operation Beijing Jiaotong University Beijing100044 China The National Mobile Communications Research Laboratory Southeast University Nanjing211189 China The Department of Electrical and Computer Engineering The University of Houston HoustonTX77004 United States The Department of Computer Science and Engineering Kyung Hee University Seoul446-701 Korea Republic of Henan Joint International Research Laboratory of Intelligent Networking and Data Analysis Zhengzhou University Zhengzhou450001 China Research Center of Networks and Communications Peng Cheng Laboratory Shenzhen China The Tsinghua Space Center the Beijing National Research Center for Information Science and Technology Tsinghua University Beijing100091 China The College of Information Engineering Shaoyang University Shaoyang422000 China The Beijing Key Lab of Transportation Data Analysis and Mining School of Computer and Information Technology Beijing Jiaotong University Beijing100044 China

Reconfigurable intelligent surface (RIS) emerges as maximization problem is formulated to facilitate RIS discrete an efficient and promising technology for the next wireless phase design and RIS placement optimization, which is subject generation networks and has attracted a lot of attention owing to coverage probability constraint. Simulation results validate to the capability of extending wireless coverage by reflecting that better coverage performance and higher travel distance signals toward targeted receivers. In this paper, we consider can be achieved with deployment of RIS. The impacts of some a RIS-assisted high-speed train (HST) communication system key system parameters including transmission power, signal-to-to enhance wireless coverage and improve coverage probability. noise ratio threshold, number of RIS elements, number of RIS First, coverage performance of the downlink single-input-single- quantization bits, horizontal distance between base station and output system is investigated, and the closed-form expression RIS, and speed of HST on system performance are investigated. of coverage probability is derived. Moreover, travel distance In addition, it is found that RIS can well improve coverage probability with limited power consumption for HST communications. Copyright © 2023, The Authors. All rights reserved.

关键词： Railroads

来源：评论

学校读者我要写书评

暂无评论

Fluid flow and heat transfer characteristics of flying-wing finned tubes in high-altitude environments

引用

International Journal of Thermal sciences 2025年 217卷

作者： Long Miao Rui Wan Kai Qiao Xi-Long Zhang Lei Zhang Hua-Wei Wu Tao Sun Lei Liu Zhen Liu School of Mechanical & Electrical Engineering Xuzhou University of Technology Xuzhou 221000 China Hubei Key Laboratory of Power System Design and Test for Electrical Vehicle Hubei University of Arts and Science Xiangyang 441053 China School of Automotive and Traffic Engineering Hubei University of Arts and Science Xiangyang 441053 China School of Mechanical and Automotive Engineering Qingdao University of Technology Qingdao 266520 China

High-altitude environments significantly influence the performance of flying-wing finned tube heat exchangers (FWFHEs); however, the specific variation patterns and the underlying mechanisms are poorly understood. To address this gap, this study systematically investigates the fluid flow and heat transfer characteristics, as well as the relevant mechanisms, of flying-wing finned tubes (FWFTs) under high-altitude conditions. The performance of the FWFHE was experimentally evaluated under simulated low-temperature ambient conditions corresponding to an altitude of 1000 m. The established simulation methodology was then validated using these experimental results. Following validation, numerical studies were conducted to examine the fluid flow and heat transfer characteristics of FWFTs over an altitude range of 0–5500 m, with inter-fin inlet air velocities from 6 to 12 m/s and Reynolds numbers ( Re ) between 1250 and 3000. The results indicate that, when the inter-fin inlet air velocity is held constant, the pressure drop, heat transfer rate, and convective heat transfer coefficient all decrease significantly with increasing altitude. Specifically, each parameter is reduced by approximately 5.5%, 5%, and 5% for every 500-m increase in altitude, respectively. Despite these dimensional changes, the primary dimensionless parameters—friction factor, corrected Nusselt number, and performance evaluation criterion—remain largely insensitive to altitude under constant Re conditions, indicating stable dimensionless fluid flow and heat transfer characteristics. This stability results from a compensatory mechanism: the increased airflow velocity needed to maintain constant Re counteracts the rise in kinematic viscosity at higher altitudes. To facilitate engineering calculations, altitude correction factors for pressure drop and heat transfer coefficient are proposed. These factors enable accurate prediction and optimization of the heat transfer area design for FWFHEs operating in

关键词：

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：