检索结果-内蒙古大学图书馆

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

作者： Ma, Sheng-Chao Shen, Kai-Yue Yin, Hua-Qiang He, Xue-Dong Li, Jun Meng, Ying-Chao Institute of Nuclear and New Energy Technology Collaborative Innovation Center of Advanced Nuclear Energy Technology Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education Tsinghua University Beijing100084 China Nuclear Power Design and Research Sub-institute Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China Institute for Chemical and Bioengineering Department of Chemistry and Applied Biosciences Swiss Federal Institute of Technology Zurich Zurich8093 Switzerland

ISBN: (纸本)9784888983051

Lots of porous carbon materials, including boron-containing carbon (BC) and isostatic pressure graphite (IG-110), are used in high-temperature gas cooled reactor (HTGR). To prevent corrosion caused by carbon-water reaction at high temperature, water absorbed in the materials needs to be removed before the reactor operation. It has become the consensus of the researchers that the pore morphology of the material has an important influence on the physical adsorption and desorption process of the gas. Therefore, it is significant to explore the migration mechanism of moisture in carbon materials by studying the pore characteristics and hydrophilic properties of the material surface. Scanning electron microscopy (SEM) and contact angles tests were used to study the surface pore characteristic and hydrophilicity of BC and IG-110. The results of SEM scanning show that a large number of irregular micropores and cracks were found on the surface of BC, while the structure of IG-110 was more compact, and the size and number of pores were obviously smaller. 3 μL and 5 μL water drops were used to contact angle tests, it was found that the average contact angle of the BC surface with water droplets is 118.04°, which is greater than that of IG-110, measured as 112°. Finally, the water vapor absorption experiment of these two materials were carried out to verify that the pore structure and hydrophilicity have an effect on water absorption, and the pore structure has a more decisive effect on moisture absorption than the hydrophilicity. © 2019 American Society of Mechanical Engineers (ASME). All rights reserved.

关键词： Scanning electron microscopy

来源：评论

学校读者我要写书评

暂无评论

A guideline study for optimal machine learning approaches to predict the off-design performance of sCO 2 -PCHEs

引用

Case Studies in Thermal Engineering 2025年 73卷

作者： Xin Sui Wenqi Wang Chunyang Liu Peixin Dong School of Mechatronic Engineering Henan University of Science and Technology Luoyang 471003 China Henan Key Laboratory for Machinery Design and Transmission System of Henan Province Luoyang 471003 China Longmen Laboratory Luoyang 471000 China Department of Mechanical Engineering The Hong Kong Polytechnic University Hong Kong Special Administrative Region

As research increasingly focuses on predicting the off-design performance of PCHEs using machine learning (ML) approaches, there is a clear need to identify the most cost-effective method that offers optimal accuracy and generalization across a wide range of operating conditions in sCO 2 power cycles. In response, this study establishes highly accurate machine learning proxies, including XGBoost, SVMs, BPNNs, and FCDNs for comparison, aiming to rank and identify the one with the best accuracy and generalization for different operating conditions of PCHEs. First, multiple datasets concerning the geometric parameters and working conditions of PCHEs are consolidated. Two data-driven techniques are introduced to correlate both inputs and outputs, identifying the most pertinent parameter. Then, the sensitivity of ML models to hyperparameter, split ratio, and data distribution is evaluated. Finally, a mutual assessment is conducted to rank their accuracy and generalization when predicting the heat transfer coefficient across three real-world operating scenarios. This study concludes that: 1) BPNN and XGBoost emerge as the best performers with the highest accuracy, achieving a MAPE of 2.938 % and 3.074 %, respectively, among eleven approaches with four ML models and seven Nu correlation-based models included; 2) BPNN and XGBoost exhibit strong generalization ability, demonstrating accuracy losses of less than 0.057 and 0.244, respectively, against unseen data; 3) unlike FCDN, which requires substantial computational time, or SVM, which produces significant errors, BPNN and XGBoost are more reliable and efficient in forecasting sCO 2 -PCHEs’ performance for future power cycle control studies that involve vast operating conditions and numerous rounds of optimization search.

关键词： Machine learning sCO 2 -PCHEs Hyperparameter optimization Generalization ability Off-design performance

来源：评论

学校读者我要写书评

暂无评论

Optimization design of the reactor coolant pump flywheel comprised of multi-ring packing heavy metal alloy

引用

Journal of Physics: Conference Series 2021年第1期1777卷

作者： L Jiang C W Wu X J Shao Y Zhang M D Yu National Key Laboratory of Science and Technology on Reactor System Design Technology Nuclear Power Institute of China Chengdu 610041 China State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology Dalian 116024 China

To improve energy storage performance of the multi-ring RCP flywheel comprised of inner hub, tungsten alloy ring and outer retainer, optimization design process for the radial thicknesses of components and interference fit assembly is demonstrated. Radial thicknesses of these components and magnitude of interference fit are set as design parameters to construct parametric analysis model. design of experiments (DOE) technique is adopted to generate design matrix for sensitive analysis. Subsequently, radial basis function (RBF) approximation is employed to search for the optimal design considering structural integrity requirement. Finally, a proper range of the magnitude of interference fit is obtained which can not only prevent neither slippage nor separation between the inner hub and tungsten alloy ring but also ensure the safety of structural strength. In addition, it is found that to ensure a high moment of inertia and energy density, a reasonable large radial thickness of tungsten alloy ring and a reasonable small radial thickness of outer retainer are required.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Performance comparation of two kinds of aircraft ram air outlet

Performance comparation of two kinds of aircraft ram air out...

引用

CSAA/IET International Conference on Aircraft Utility systems 2020, AUS 2020

作者： Zhimao, Li Xinlong, Zhu Boyu, Wu Houju, Pei Wenbing, Xu Hong, Shi Environment Control and Oxygen System Department Shanghai Aircraft Design and Research Institute Shanghai201210 China College of Energy and Power Jiangsu University of Science and Technology Zhenjiang212003 China Key Laboratory of Aircraft Environment Control and Life Support MIT Nanjing University of Aeronautics and Astronautics Nanjing210016 China

ISBN: (纸本)9781839535635

With the development of electronic equipment integration technology, the air demand for cooling in cabin and electronic system is increasing continuously. The ram air outlet plays an important role in the airflow system. In this paper, the three-dimensional modeling of the door-type ram air outlet and the grille-type ram air outlet is carried out. Then, the flow characteristics and resistance characteristics of ram air outlet are analyzed based on structured grid technology. The results show that the flow rate of the door panel ram air outlet is greater than that of the grille-type ram air outlet in the same size, the discharge rate of the door panel outlet is 0.3kg/s more than that of the grille-type outlet under the design condition, and the skin surface temperature at the back of the door panel outlet is 13.5K lower than that of the grille outlet. Therefore, the door-type ram air outlet has better emission characteristics and flow characteristics, which is more suitable for the aircraft in this research. This study provides a technical reference for the design of the civil aircraft. © 2020 Institution of Engineering and technology. All rights reserved.

关键词： Aircraft

来源：评论

学校读者我要写书评

暂无评论

Forecasting Covid-19 New Cases Through the Mixed Generalized Inverse Weibull Distribution and Time Series Model

SSRN

引用

SSRN 2023年

作者： Chang, Yiming Tao, YinYing Shan, Wei Yu, Xiangyuan No.37 Xueyuan Road Haidian District Beijing China School of Design and Fashion Zhejiang University of Science and Technology No.318 Liuhe Road Xihu District Zhejiang Hangzhou China School of Economics and Management Beihang University No.37 Xueyuan Road Haidian District Beijing China Key Laboratory of Complex System Analysis and Management Decision Ministry of Education No.37 Xueyuan Road Haidian District Beijing China School of Economics and Management Beijing Jiaotong University No.3 Shangyuancun Haidian District Beijing China

In this paper, the MGIW-ARIMA model is proposed to predict the newly diagnosed cases of COVID-19. The MGIW model is used to predict the trend components, and the ARIMA model is used to predict the random components. Finally, the estimated results of trend components and random components are added together to get the eventual predictions. The data of COVID-19 in the United States is used to verify and evaluate the model. In the short-term prediction, the combined model of MGIW-ARIMA is better than the single MGIW model. In the long-term prediction, the prediction accuracy of the MGIW model is slightly higher than that of the MGIW- ARIMA model. The MGIW-ARIMA model proposed in this paper makes up for the shortcoming of the lack of randomness in the estimated values of the MGIW model. The combination model can effectively capture the short-term changes of the epidemic while grasping the long-term development trend. © 2023, The Authors. All rights reserved.

关键词： COVID-19

来源：评论

学校读者我要写书评

暂无评论

I3−/I−Redox Reaction-mediated Organic Zinc-Air Batteries with Accelerated Kinetics and Long Shelf Lives

引用

Angewandte Chemie 2023年第26期135卷

作者： Mangwei Cui Ninggui Ma Hao Lei Youfa Liu Wei Ling Sheng Chen Jiaqi Wang Prof. Hongfei Li Zhaohui Li Prof. Jun Fan Prof. Yan Huang State Key Laboratory of Advanced Welding and Joining Sauvage Laboratory for Smart Materials Shenzhen Key Laboratory of Flexible Printed Electronics Technology School of Materials Science and Engineering Harbin Institute of Technology (Shenzhen) Shenzhen 518055 China Department of Materials Science and Engineering City University of Hong Kong 83 Tat Chee Avenue Kowloon Hong Kong 999077 China Key Laboratory of Radiation Physics and Technology of Ministry of Education Institute of Nuclear Science and Technology Sichuan University Chengdu 610064 China School of System Design and Intelligent Manufacturing Southern University of Science and Technology Shenzhen 518055 China Songshan Lake Materials Laboratory Dongguan 523808 China Shenzhen China Star Optoelectronic Semiconductor Display Technology Co. Ltd. Shenzhen 518055 China

The storage time of Zn-air batteries (ZABs) for practical implementation have been neglected long-lastingly. ZABs based on organic solvents promise long shelf lives but suffer from sluggish kinetics. Here, we report a longly storable ZAB with accelerated kinetics mediated by I 3 − /I − redox. In the charge process, the electrooxidation of Zn 5 (OH) 8 Cl 2 ⋅H 2 O is accelerated by I 3 − chemical oxidation. In the discharge process, I − adsorbed on the electrocatalyst changes the energy level of oxygen reduction reaction (ORR). Benefitting from these advantages, the prepared ZAB shows remarkably improved round-trip efficiency (56.03 % vs. 30.97 % without the mediator), and long-term cycling time (>2600 h) in ambient air without replacing any components or applying any protective treatment to Zn anode and electrocatalyst. After resting for 30 days without any protection, it can still directly discharge continuously for 32.5 h and charge/discharge very stably for 2200 h (440 cycles), which is evidently superior to aqueous ZABs (only 0/0.25 h, and 50/25 h (10/5 cycles) by mild/alkaline electrolyte replenishment). This study provides a strategy to solve both storage and sluggish kinetics issues that have been plaguing ZABs for centuries, opening up a new avenue to the industrial application of ZABs.

关键词： Iodine-Containing Reaction Kinetics Redox Mediators Storage Time Zn-Air Batteries

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

引用

Procedia CIRP 2021年 97卷 230-234页

作者： Yuanyang Zhang Junkang Guo Xianming Gao Jun Hong School of Mechanical Engineering Xi'an Jiaotong University Xi'an Shaanxi 710049 P R China Key Laboratory for Modern Design & Rotor-Bearing System Ministry of Education Xi'an Jiaotong University Xi'an Shaanxi 710049 P R China College of Mechanical and Electrical Engineering Shaanxi University of Science and Technology Xi'an 710021 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.

关键词： Assembly design Form error Spring contact model Finite element method

来源：评论

学校读者我要写书评

暂无评论

Multi-Scale Fusion Algorithm for AUVs Integrated Navigation systems

引用

Journal of Beijing Institute of technology 2019年第4期28卷 725-730页

作者： Yushan Sun Fanyu Wu Yuqi Wang Guocheng Zhang Bin Kong Science and Technology on Underwater Vehicle Laboratory Harbin Engineering UniversityHarbin 150001China Key Laboratory of System Control and Information Processing Shanghai Jiao Tong UniversityShanghai 200030China Wuhan Second Ship Design and Research Institute Wuhan 430205China

To deal with the low location accuracy issue of existing underwater navigation technologies in autonomous underwater vehicles(AUVs),a distributed fusion algorithm which combines the model's analysis method with a multi-scale transformation method is proposed for integrated navigation system based on ***,integrated navigation system theory and system error sources are introduced in ***,a navigation system's observation equation on the original scale is decomposed into different scales by the discrete wavelet transform method,and noise reduction is performed by setting the wavelet de-noising *** last,the dynamic equation and observation equations are fused on different scales by the wavelet transformation and Kalman *** results show that the proposed algorithm has smaller navigation error and higher navigation accuracy.

关键词： autonomous underwater vehicles(AUVs) integrated navigation system wavelet transform multi-scale transform Kalman filter

来源：评论

学校读者我要写书评

暂无评论

A Service-Environment-Oriented Shape Reconstruction Method of Vehicle-borne Active Phased Array Antenna

A Service-Environment-Oriented Shape Reconstruction Method o...

引用

IEEE International Conference on Radar

作者： Pengying Xu Xiaoxian Xu Yan Wang Yucheng Teng Congsi Wang Dongming Ge Mingkui Kang Shuai Yuan Xuezi Wang Key Laboratory of Electronic Equipment Structure Design Ministry of Education Xidian University Xi'an China School of Information and Control Engineering Xi'an University of Architecture and Technology Xi'an China Beijing Institute of Spacecraft System Engineering Beijing China No.771 Institute of China Aerospace Science and Technology Corporation Xi'an China China Electronics Technology Group Corporation No.38 Research Institute Hefei China

ISBN: (纸本)9781665468893

Modern electronic equipment has been moving towards large scale and increased complexity. Affected by such factors as complex working environments, the performance of a large number of structures in engineering is degraded or even destroyed. Therefore, structure shape estimation is of great significance. The complexity of the structure, however, makes it impossible for a single deformation evaluation algorithm to evaluate the structure comprehensively and accurately. In this paper, a modal-approximate curve (M-AC) method, using a small amount of strain data, is proposed for block shape estimation of structures. Three typical wind load experiments are carried out on the finite element model (FEM) of the vehicle-borne active phased array antenna, and the effectiveness of the algorithm is verified. Under the wind speed of 28 (m/s), the deformation of antenna front is 104.70 mm and the estimation accuracy of the M-AC method is 87.43%, which is 16.47% higher than that of the modal approach. The results indicate that the estimated displacement is consistent well with the simulation results of the finite element method.

关键词： Phased arrays Shape Estimation Radar Radar antennas Finite element analysis Loaded antennas

来源：评论

学校读者我要写书评

暂无评论

The Power Control Method of Data Center Based on Cloud- Edge Collaboration

引用

Journal of Physics: Conference Series 2021年第1期1754卷

作者： Junjie Zhao Yucheng Hou Liu Liu Feng Xie Xiang Mao Pan Luo Jinxin Wang Zhiqiang Zhang Jiang Deng Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu 610213 China Key Laboratory of the Ministry of Education on Smart Power Grids (Tianjin University) Tianjin 300072 China

Data centers have the characteristics of huge energy consumption and strong power fluctuations. To solve the problem of unstable supply and demand such as frequent power fluctuations in the micro-grid of the data center using renewable energies, this paper establishes a controllable load model of server clusters based on the task migration mechanism by analyzing the various tasks and characteristics of large cloud data centers, as well as edge computing nodes. Through the collaborative optimization control of edge and cloud computing tasks, and dynamically adjusting and migrating the server cluster load, a new data center tie-line power control method is proposed. The results of calculation examples show that the method can achieve power smoothing of large-scale cloud data center tie lines through cloud-edge collaborative control.

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：