检索结果-南通市图书馆

Temperature Difference and Stack Plate Spacing Effects on Thermodynamic Performances of Standing-Wave Thermoacoustic Engines Driven by Cryogenic Liquids and Waste Heat

引用

Journal of Thermal Science 2022年第5期31卷 1434-1451页

作者： GUO Lixian ZHAO Dan BECKER sid Department of Mechanical Engineering College of EngineeringUniversity of CanterburyPrivate Bag 4800Christchurch8041New Zealand

The standing-wave thermoacoustic engines(TAE)are applied in practice to convert thermal power into acoustic one to generate electricity or to drive cooling *** there is a number of existing numerical researches that provides a design tool for predicting standing-wave TAE performances,few existing works that compare TAE driven by cryogenic liquids and waste heat,and optimize its performance by varying the stack plate *** present work is primarily concerned with the numerical investigation of the performance of TAEs driven by cryogenic liquids and waste *** this,three-dimensional(3-D)standing-wave TAE models are ***-and time-independence studies are conducted *** validations are then performed by comparing with the numerical results available in the *** validated model is then applied to simulate the standing-wave TAEs driven by the cryogenic liquids and the waste heat,as the temperature gradientΔT is *** is found that limit cycle oscillations in both systems are successfully generated and the oscillations amplitude is increased with increasedΔ*** is identified with acoustic streaming and the flow reversal occurring through the *** studied are then conducted between the cryogenic liquid-driven TAE and that driven by waste heat in the presence of the same temperature gradientΔ*** is shown that the limit cycle frequency of the cryogenic liquid system is 4.72%smaller and the critical temperatureΔT_(cri)=131 K is lower than that of the waste heat system(ΔT_(cri)=187 K).Furthermore,the acoustic power is increased by 31%and the energy conversion efficiency is found to increase by 0.42%.Finally,optimization studies on the stack plate spacing are conducted in TAE system driven by cryogenic *** is found that the limit cycle oscillation frequency is increased with the decreased ratio between the stack plate spacing and the heat penetration *** the ratio is set to between 2 and

关键词： thermoacoustic engine standing-wave cryogenic thermodynamics acoustical energy plate spacing heat transfer acoustic streaming

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Static and dynamic stability responses of multilayer functionally graded carbon nanotubes reinforced composite nanoplates via quasi 3D nonlocal strain gradient theory

引用

Defence Technology（防务技术） 2022年第10期18卷 1778-1809页

作者： Ahmed Amine Daikh Mohamed sid Ahmed Houari Mohamed Ouejdi Belarbi Salwa A.Mohamed Mohamed A.Eltaher Laboratoire D'Etude des Structures et de Mecanique des Materiaux Departement de Genie CivilFacultedes Sciences et de La TechnologieUniversite Mustapha Stambouli B.P.305R.P.29000MascaraAlgeria Laboratoire de Genie Energetique et Materiaux LGEMUniversite de BiskraB.P.145R.P07000BiskraAlgeria Department of Engineering Mathematics Zagazig UniversityP.O.Box 44519ZagazigEgypt Faculty of Engineering Mechanical Engineering DepartmentKing Abdulaziz UniversityP.O.Box 80204JeddahSaudi Arabia Faculty of Engineering Mechanical Design and Production DepartmentZagazig UniversityP.O.Box 44519ZagazigEgypt

This manuscript presents the comprehensive study of thickness stretching effects on the free vibration,static stability and bending of multilayer functionally graded(FG)carbon nanotubes reinforced composite(CNTRC)*** nanoscale and microstructure influences are considered through a modified nonlocal strain gradient continuum *** on power-law functions,four different patterns of CNTs distribution are considered in this analysis,a uniform distribution UD,FG-V CNTRC,FG-X CNTRC,and FG-O CNTRC.A 3D kinematic shear deformation theory is proposed to include the stretching influence,which is neglected in classical ***'s principle is applied to derive the governing equations of motion and associated boundary *** solutions are developed based on Galerkin method to solve the governing equilibrium equations based on the generalized higher-order shear deformation theory and the nonlocal strain gradient theory and get the static bending,buckling loads,and natural frequencies of *** with previous works is presented.A detailed parametric analysis is carried out to highlight the impact of thickness stretching,length scale parameter(nonlocal),material scale parameter(gradient),CNTs distribution pattern,geometry of the plate,various boundary conditions and the total number of layers on the stresses,deformation,critical buckling loads and vibration *** new results are also reported in the current study,which will serve as a benchmark for future research.

关键词： 3D shear deformation theory Free vibration Buckling Bending Galerkin method Functionally graded nanotube Nonlocal strain gradient theory

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

SOME PROPERTIES OF m-ISOMETRIES AND m-INVERTIBLE OPERATORS ON BANACH SPACES

引用

Acta Mathematica Scientia 2012年第2期32卷 520-530页

作者： Ould Ahmed Mahmoud sid Ahmed Department of Mathematics College of ScienceAljouf UniversityAljouf 2014Saudi Arabia

This article has two purposes： the first is to give some structure results for the class of m-isometries, and the second purpose is to extend the notions of left and right inverses to m-left and m-right inverses resp... 详细信息

关键词： m-isometry m-left inverse m-right inverse approximate spectrum pointspectrum

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A robust model-free controller for a three-phase grid-connected photovoltaic system based on ultra-local model

引用

Protection and Control of Modern Power Systems 2021年第1期6卷 538-550页

作者： Ahsene Boubakir sid-Ahmed Touil Salim Labiod Nasserdine Boudjerda LAJ Faculty of Science and TechnologyUniversity of JijelBP.98Ouled Aissa18000JijelAlgeria Department of Electrical Engineering University of JijelJijelAlgeria LER Faculty of Sciences and TechnologyUniversity of JijelBP 98Ouled Aissa18000JijelAlgeria

In this paper, a robust model-free controller for a grid-connected photovoltaic (PV) system is designed. The system consists of a PV generator connected to a three-phase grid by a DC/AC converter. The control objectives of the overall system are to extract maximum power from the PV source, to control reactive power exchange and to improve the quality of the current injected into the grid. The model-free control technique is based on the use of an ultra-local model instead of the dynamic model of the overall system. The local model is continuously updated based on a numerical differentiator using only the input–output behavior of the controlled system. The model-free controller consists of a classical feedback controller and a compensator for the effects of internal parameter changes and external disturbances. Simulation results illustrate the efficiency of the controller for grid-connected PV systems.

关键词： Photovoltaic system Maximum power point Model-free control Ultra-local model Numerical differentiator

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

COVID-19 and Learning Styles: GCET as Case Study

引用

Computers, Materials & Continua 2021年第7期68卷 103-115页

作者： Mazhar Hussain Malik sid Ahmed Amjed Sulaiman Al Hasani Department of Computing and Information Technology Global College of Engineering and TechnologyMuscatSultanate of Oman Department of Electrical and Electronics Engineering Global College of Engineering and TechnologyMuscatSultanate of Oman

The COVID-19 pandemic has caused higher educational institutions around the world to close campus-based activities and move to online *** aim of this paper is to present the case of Global College of Engineering and Technology(GCET)and how its practices including teaching,students/staff support,assessments,and exam policies were *** paper investigates the mediating role of no detriment policy impact on students’result along with the challenges faced by the higher educational institution,recommendations and *** investigation concludes that the strategies adopted for online delivery,student support,assessments and exam policies have helped students to effectively cope with the teaching and learning challenges posed by the COVID-19 pandemic without affecting their academic *** study shows that 99%of students were able to maintain the same or better level of performance during the 1st COVID-19 *** percent of students had shown a slight decrease in their performance(about 1%–2%)with respect to their overall marks *** no detriment policy has succoured those 1%of the students to maintain their overall performance to what it used to be pre-COVID-19 ***,the paper provides the list of challenges and suggestions for smooth conduction of online education.

关键词： Higher education learning styles COVID-19 challenges and strategies no detriment policy engineering and technology modules

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IPv6 Cryptographically Generated Address:Analysis,Optimization and Protection

引用

Computers, Materials & Continua 2021年第7期68卷 247-265页

作者： Amjed sid Ahmed Rosilah Hassan Faizan Qamar Mazhar Malik Department of Computing and Information Technology Global College of Engineering and TechnologyRuwi112Sultanate of Oman Faculty of Information Science and Technology Center for Cyber SecurityUniversiti Kebangsaan MalaysiaBangi43600Malaysia Faculty of Information Science and Technology Universiti Kebangsaan Malaysia43600BangiMalaysia

In networking,one major difficulty that nodes suffer from is the need for their addresses to be generated and verified without relying on a third party or public authorized *** resolve this issue,the use of selfcertifying addresses have become a highly popular and standardized method,of which Cryptographically Generated Addresses(CGA)is a prime *** was primarily designed to deter the theft of IPv6 addresses by binding the generated address to a public key to prove address *** though the CGA technique is highly effective,this method is still subject to several vulnerabilities with respect to security,in addition to certain limitations in its *** this study,the authors present an intensive systematic review of the literature to explore the technical specifications of CGA,its challenges,and existing proposals to enhance the *** that CGA generation is a time-consuming process,this limitation has hampered the application of CGA in mobile environments where nodes have limited energy and *** Hash2 conditions in CGA is the heaviest and most timeconsuming part of *** improve the performance of CGA,we replaced the Secure Hash Algorithm(SHA1)with the Message Digest(MD5)hash ***,this study also analyzes the possible methods through which a CGA could be *** conducting this analysis,Denial-of-Service(DoS)attacks were identified as the main method of attack toward the CGA verification process,which compromise and threaten the privacy of ***,we propose some modifications to the CGA standard verification algorithm to mitigate DoS attacks and to make CGA more security conscious.

关键词： IPv6 GCA SEND DoS attacks RSA SHA-1

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

阿尔及利亚与中国饮食文化的对比研究

阿尔及利亚与中国饮食文化的对比研究

引用

作者： ZEROUKI sid ALI（斯大利）绍兴文理学院

学位级别：硕士

饮食,是人类的基本需求之一,也是人类赖以生存的物质基础,它反映着不同地域的不同文化特征。中国地域辽阔,地理环境多样,历史悠久,物产丰富,动植物种类繁多,为中国广博多样饮食文化的形成提供了充足的产品资源。阿尔及利亚位于非洲西北... 详细信息

饮食,是人类的基本需求之一,也是人类赖以生存的物质基础,它反映着不同地域的不同文化特征。中国地域辽阔,地理环境多样,历史悠久,物产丰富,动植物种类繁多,为中国广博多样饮食文化的形成提供了充足的产品资源。阿尔及利亚位于非洲西北部,北部沿海地区属地中海气候。中部为旱、雨两季的热带草原气候。南部沙漠地区形成了典型的热带沙漠气候。其食物的特征是丰富的陆地和海洋食材来源。食物承载着文化意义,饮食文化具有民族性。我们可以通过食物与文化的关系,去探讨民族文化的精神内涵与形式。本文将着重通过文化对比的研究模式,比较阿尔及利亚和中国的饮食文化差异,使人们更好了解两国饮食差异的具体内容,更好的理解现象背后的深层次原因。本论文主要从六个部分进行论述。第一部分是绪论部分,介绍了论文的背景和意义,以及论文的创新之处。第二部分对相关学者就饮食文化的研究文献进行了综述,并阐述了本文研究方向。第三部分具体阐述阿尔及利亚和中国的饮食文化特点以及两者的相似之处。第四部分从饮食历史、饮食观念、饮食内容、烹饪方式、饮食礼仪五个方面比较了阿尔及利亚和中国饮食文化的差异。第五部分主要从宗教和地理因素两个方面分析引起阿尔及利亚和中国饮食文化的差异的原因。第六部分对全文进行了简要总结。本文的研究希望能让两国成员更好地互相了解对方国家的饮食文化。

关键词：饮食文化文化差异文化交流中国阿尔及利亚

来源：

同方学位论文库评论

在线全文

同方学位论文库

学校读者我要写书评

暂无评论

Effects of Maternal Linseed Oil Supplementation on Metabolic Parameters in Cafeteria Diet-induced Obese Rats

引用

Biomedical and Environmental Sciences 2015年第4期28卷 298-302页

作者： BENAISSA Nawel MERZOUK Hafida MERZOUK sid Ahmed NARCE Michel Laboratory of Physiology and Biochemistry of Nutrition Department of Biology Faculty of Natural and Life SciencesEarth and Universe University Abou-Bekr Belka?d Department of technical Sciences Faculty of Engineering University Abou-Bekr Belka?d INSERM UMR 866 ‘Lipids Nutrition Cancer’ University of Burgundy Faculty of Sciences 6 Boulevard Gabriel Dijon 21000 France

Because linseed oil may influence maternal and fetal metabolisms, we investigated its role in the modulation of lipid metabolism in cafeteria diet-induced obese rats and their offspring. Female Wistar rats were fed control or cafeteria food, which were either supplemented or not supplemented with linseed oil （5%） for I month before and during gestation. At parturition, serum and tissue lipids and enzyme activities were analyzed. Cafeteria diet induced adverse metabolic alterations in both mothers and offspring. Linseed oil improved metabolic status. In conclusion, linseed oil displayed health benefits by modulating tissue enzyme activities in both obese mothers and their newborns.

关键词： OB Effects of Maternal Linseed Oil Supplementation on Metabolic Parameters in Cafeteria Diet-induced Obese Rats

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Blood Oxidant/Antioxidant Status in overfed Aging Rats: Comparative Effects of Sunflower and Olive-Linseed Mixture Oil Rich Diets

引用

Biomedical and Environmental Sciences 2013年第9期26卷 765-768页

作者： AYAD Amina MERZOUK Hafida MERZOUK sid Ahmed NARCE Michel Laboratory of Physiology and Biochemistry of Nutrition Department of Biology Faculty of Natural and Life SciencesEarth and Universe University Abou-Bekr Belkad Department of technical sciences Faculty of Engineering University Abou-Bekr Belkad INSERM UMR 866 "Lipids Nutrition Cancer"University of Burgundy Faculty of Sciences 6 Boulevard Gabriel

Obesity, one of the most common health problems, is associated with glucose and lipid metabolism abnormalities, increased cardiovascular risk and oxidative stressI1}. Aging is also associated with an increase in oxidative stress[2]. Considering that older adults are already at risk for oxidant stress, the additional metabolic perturbations of obesity aggravated the susceptibility to oxidant stress. Modulating age-related oxidative stress via dietary interventions could reduce free radical production and significantly improve health in aging.

关键词： Comparative Effects of Sunflower and Olive-Linseed Mixture Oil Rich Diets Blood Oxidant/Antioxidant Status in overfed Aging Rats CAF PUFA

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Robust direct power control based on the Lyapunov theory of a grid-connected brushless doubly fed induction generator

引用

Frontiers in Energy 2016年第3期10卷 298-307页

作者： M. Abdelbasset MAHBOUB Said DRID M. A. sid Ridha CHEIKH LSPIE Laboratory of Propulsion-Induction Electromagnetic Department Electrical Engineering University of Bama Batna 05000 Algeria LAS Laboratory Department of Electrical Engineering Setif UniversitySetif 19000 Algeria LGEB Laboratory Department of Electrical Engineering Biskra University Biskra 07000 Algeria UDES Unit6 de Drveloppement des Equipement Solaires Centre de eveloppement des Energies Renouvelables Tipaza 42415 Algeria

This paper deals with robust direct power control of a grid-connected bmshless doubly-fed induction generator（BDFIG）. Using a nonlinear feedback lineariza- tion strategy, an attempt is made to improve the desired performances by controlling the generated stator active and reactive power in a linear and decoupled manner. There- fore, to achieve this objective, the Lyapunov approach is used associated with a sliding mode control to guarantee the global asymptotical stability. Thus, an optimal operation of the BDFIG in sub-synchronous operation is obtained as well as the stator power flows with the possibility of keeping stator power factor at a unity. The proposed method is tested with the Matlab/Simulink software. Simulation results illustrate the performances and the feasibility of the designed control.

关键词： brushless doubly fed induction generator(BDFIG) vector control Lyapunov theory power factor unity active and reactive power

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

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：