期刊文献+
共找到108,054篇文章
< 1 2 250 >
每页显示 20 50 100
Exploration on Teaching Reform and Talent Cultivation in Environmental Health from the Perspective of“Double First-Class”Construction
1
作者 Xi Wang Chaowei Wang +6 位作者 Yang Liu Lian Liu Lulu Bai Liangyu Cui Qi Jing Yuyang Ma Yujie Ning 《Journal of Contemporary Educational Research》 2025年第11期329-335,共7页
The“Double First-Class”construction focuses on the development of disciplinary connotations and the improvement of talent cultivation quality,posing higher demands on the teaching mode and talent supply of public he... The“Double First-Class”construction focuses on the development of disciplinary connotations and the improvement of talent cultivation quality,posing higher demands on the teaching mode and talent supply of public health and preventive medicine disciplines.Environmental health,as a core course in public health and preventive medicine,directly relates to the cultivation of effective composite public health talents.Based on the core orientation of the“Double First-Class”construction and combining the talent cultivation and course characteristics of environmental health,this paper explores the significance of teaching reform and talent cultivation in environmental health from the perspective of“Double First-Class”construction.It also investigates the paths for teaching reform and talent cultivation from multiple dimensions,aiming to provide references for cultivating high-quality professionals who meet the needs of national public health development and ecological environmental protection. 展开更多
关键词 double first-class”construction Environmental health Teaching reform Talent cultivation Practical teaching innovation
在线阅读 下载PDF
Research on Development Strategies for“Double First-Class”Construction of Subject Service in University Libraries
2
作者 Haixin Liu Liping Liu Yanan Zhang 《Journal of Contemporary Educational Research》 2025年第1期25-31,共7页
This paper aims to explore the development strategies for subject services in university libraries within the context of the“double first-class”initiative.By examining the relationship between“double first-class”c... This paper aims to explore the development strategies for subject services in university libraries within the context of the“double first-class”initiative.By examining the relationship between“double first-class”construction and university library subject services,the study analyzes the current state of subject services,including resource development,service models,and team building.Drawing on domestic and international case studies,the paper proposes a series of targeted and practical strategies to enhance the quality of subject services in university libraries,thereby providing robust support for the advancement of the“double first-class”initiative. 展开更多
关键词 double first-class”construction University library Subject service Development strategy
在线阅读 下载PDF
Build an International Teaching Resource Construction System and Practice International Talent Training in the Context of “Double First-class” ——Take the School of Software of Northwestern Polytechnical University Case as an Example
3
作者 Liming Lin Jiangbin Zheng +1 位作者 Chunyan Ma Qianru Wei 《计算机教育》 2022年第12期163-170,共8页
From the perspective of the development of world-class universities,internationalization is an essential strategic choice and external feature,and also an inevitable choice to improve the discourse power and competiti... From the perspective of the development of world-class universities,internationalization is an essential strategic choice and external feature,and also an inevitable choice to improve the discourse power and competitiveness of international higher education.In line with the national“double first-class”international development strategy of higher education,based on the cultivation of students’overall quality,the improvement of teachers’professional ability,and the development of school’s improvement of quality and efficiency,we School of Software,Northwestern Polytechnical University,explore new ideas and new measures for the cultivation of international software engineering talents,build a set of international teaching resources construction system,to form a reference standard and scheme for the cultivation of international software engineering talents.At present,we have achieved excellent results. 展开更多
关键词 double first-class International teaching resources construction system INTERNATIONALIZATION Talents’training
在线阅读 下载PDF
Research on the Curriculum System of Software Engineering under the Background of“Double First-Class”Construction
4
作者 Bo Liu Qing Zhu +1 位作者 Hongli Chen Jidong Zhang 《计算机教育》 2020年第12期126-133,共8页
To build the top class of higher education by focusing on the goal of the“Double First-Class”,it needs to analyze the defect and deficiency and identify the demand for the training of the talent under the background... To build the top class of higher education by focusing on the goal of the“Double First-Class”,it needs to analyze the defect and deficiency and identify the demand for the training of the talent under the background of“Double First-Class”.Considering of those issues,it is suggested that building the curriculum system scientifically and rationally in following aspects:deepening the training objectives,professionalizing the structure and contents of the curriculum system,optimizing the content,enhancing the construction of practical education system and internationalizing the curriculum system.Also,with those aspects,a reference is provided for the cultivation of talents with innovative consciousness and ability to solve complex engineering problems under the background of the“Double First-Class”construction. 展开更多
关键词 double first-class”construction software engineering ability training
在线阅读 下载PDF
Construction of University Librarian Team in the Context of Double First-Class Initiative
5
作者 Jin MENG 《Asian Agricultural Research》 2023年第6期51-55,共5页
Data services,knowledge services,and information services are the core service elements of university libraries in the context of the Double First-Class Initiative.Combined with the current situation of insufficient o... Data services,knowledge services,and information services are the core service elements of university libraries in the context of the Double First-Class Initiative.Combined with the current situation of insufficient overall service capacity of libraries,this paper proposed strategies and implementation paths for optimizing the service system from three aspects:the construction of the professional qualification system for librarians,the establishment of post institutions,and the construction of library culture.Long-term path:putting library human resource management into the legal track,taking the lead in local legislation,and promoting the construction of library legislation and professional qualification certification system;optimizing the personnel system,implementing hierarchical management and classified assessment for professional librarians and auxiliary librarians.Short-term path:intensive post allocation,namely,assigning the core strength in the core post,and tackling the temporary major work combining multiple forces in the form of a"working group";building an open knowledge service ecosystem,accelerate the cross-border integration of libraries and other organizations,and striving to build the core competitiveness of libraries. 展开更多
关键词 UNIVERSITY double first-class Initiative Construction of university librarian team
在线阅读 下载PDF
Research on the cultural transmission of college students under the background of the "double first-class"university construction
6
作者 HU Xianglong 《International English Education Research》 2018年第4期91-93,共3页
Throughout the world's first-class universities, the university culture is the soul of the universities' survival and development, and the cultural competitiveness has become an important symbol of the core competit... Throughout the world's first-class universities, the university culture is the soul of the universities' survival and development, and the cultural competitiveness has become an important symbol of the core competitiveness of the universities. The first-class university culture is very important to the construction of the "double first-class". Therefore, our country should bring the university cultural construction into the big pattern of the "double first-class" construction, guide the construction of the university cultures with the socialist core values, strengthen the cultural confidence, inherit the Chinese excellent traditional cultures, pay attention to the rational exchange of the multicultural cultures, highlight the Chinese characteristics of the first-class university cultures, and realize the dream of the Chinese nation of a power of the higher education. 展开更多
关键词 double first-class university construction background university students cultural heritage work modem education
在线阅读 下载PDF
Research on Striving for Double First-Class Universities
7
作者 Xinmian Zan 《Journal of Contemporary Educational Research》 2020年第6期97-100,共4页
The construction of“double first-class”universities is the strategic goal of the development of Chinese universities in the new period.On the basis of fully researching the domestic“double first-class”talent train... The construction of“double first-class”universities is the strategic goal of the development of Chinese universities in the new period.On the basis of fully researching the domestic“double first-class”talent training model,this paper builds a new type of talent training model with Chinese characteristics suitable for the“double first-class”development requirements through reference,digestion,comparison and integration,hoping to further improve universities Quality of teaching. 展开更多
关键词 double first-class Colleges and universities Talents MODE
在线阅读 下载PDF
Optimizing University Faculty Teams: Addressing the Talent Mobility Challenges in the Context of “Double First-Class” Initiative
8
作者 Shanhong Zhang Yuming Song Hongbo Shi 《教育研究前沿(中英文版)》 2024年第3期1-7,共7页
With the advancement of the“Double First-Class”initiative,universities are increasingly focusing on attracting top-tier talent to enhance faculty quality and strengthen academic disciplines.The blind competition for... With the advancement of the“Double First-Class”initiative,universities are increasingly focusing on attracting top-tier talent to enhance faculty quality and strengthen academic disciplines.The blind competition for high-end talent among universities reflects an overshadowing of academic values by economic considerations,neglecting the growth patterns of top talent and the development laws of higher education.This study investigates and reflects on the real-world challenges of faculty mobility in universities,aiming to provide effective guidance for managing university faculty teams. 展开更多
关键词 double first-class”Initiative Higher Education Institutions Faculty Teams Talent Cultivation
在线阅读 下载PDF
Research on the Application of Virtual Medical Technology in Internet+ under the Background of "Double First-Class" Universities
9
作者 ZHENGShengxia HUMeihong +2 位作者 GUOTonghang LIUCheng LIURan 《外文科技期刊数据库(文摘版)教育科学》 2022年第3期151-154,共4页
Objective: to explore the application effect of virtual medical technology in reproductive teaching under the background of "two-class" universities. Methods: the subjects of the study were the undergraduate... Objective: to explore the application effect of virtual medical technology in reproductive teaching under the background of "two-class" universities. Methods: the subjects of the study were the undergraduate students of clinical medicine in Anhui Medical University. The number is about 80. They were randomly divided into two groups with 40 people in each group. There was no significant difference in learning achievement and intelligence test scores between the two groups. The teaching time and place of the two groups of students are basically the same. All students are required to preview the teaching contents in advance. The traditional teaching group was the control group, while the virtual medical technology teaching group was the research group (P<0.05). Results: after comparison, the study group's students' academic performance was higher than that of the control group, and the study group's students' satisfaction with the teaching methods was higher than that of the control group (P<0.05). Conclusion: the effect of applying virtual medical technology in reproductive teaching is better than that of traditional teaching method. The students' test scores are ideal and they have high recognition of virtual medical technology. 展开更多
关键词 "double first-class" internet + virtual medicine reproductive medicine teaching
在线阅读 下载PDF
Application and Discussion on the Training of Innovative Graduate Talent Against the Background of“Double First-Class”Construction
10
作者 Lijiang Yu Yunlong Ji 《Journal of Contemporary Educational Research》 2024年第12期150-156,共7页
Against the background of the“double first-class”construction,the training of innovative graduate talent has become an important issue in higher education.This article discusses the importance of the training of top... Against the background of the“double first-class”construction,the training of innovative graduate talent has become an important issue in higher education.This article discusses the importance of the training of top graduate innovative talent,analyzes the status of the training of top graduate innovative talent at home and abroad,and summarizes the current challenges in the training of graduate innovative talent in China.Lastly,this paper proposes relevant reform suggestions in response to problems in the training of innovative graduate talent,which provides important references for improving the quality of innovative graduate training. 展开更多
关键词 double first-class”construction Graduate students Cultivation of innovative talent
在线阅读 下载PDF
Critical Policy Analysis of the Second Round of the Double First-Class Initiative in China
11
作者 Gaoming Zheng Weiwei Li 《ECNU Review of Education》 2025年第3期704-724,共21页
Purpose:This critical policy analysis aims to comprehensively examine the second round of China's first-class discipline development project,commonly known as the Double First-Class Initiative(DFC Initiative or Sh... Purpose:This critical policy analysis aims to comprehensively examine the second round of China's first-class discipline development project,commonly known as the Double First-Class Initiative(DFC Initiative or Shuang Yiliu Jianshe).Design/Approach/Methods:We conducted desk research between May 2022 and December 2023 using relevant policy documents,academic literature,news sources,and commentaries that specifically focused on the second round of the DFC Initiative in China.Employing a critical policy analysis approach,we analyzed the gathered data from three key perspectives:policy as text,policy as discourse,and policy effects(including both first-and second-order effects).Findings:The second round of the DFC Initiative was implemented within the context of strengthened state regulation,prevalent managerialism,and an emphasis on promoting education equality in China's higher education development.A notable shift in structural dynamics occurred between the first and second round.These include the possibility of universities being added to or removed from the official list,increased academic autonomy for selected universities,and the promotion of interdisciplinary research within specific institutions.The implementation of the second round of the DFC Initiative reflects China's commitment to developing an internationalization strategy with Chinese characteristics.This strategy aims to align with China's national strategic needs and position the country as a cooperative partner,promoter,competitor,and potential leader in global scholarship.Originality/Value:By employing a critical policy analysis approach,this study offers a comprehensive examination of the second round of the DFC Initiative in China,contributing to existing knowledge on the development of world-class university policies in the country. 展开更多
关键词 China critical policy analysis double first-class Initiative higher education internationalization strategy
原文传递
Constructing Double Heterojunctions on 1T/2H-MoS_(2)@Co_(3)S_(4)Electrocatalysts for Regulating Li_(2)O_(2)Formation in Lithium-Oxygen Batteries
12
作者 Yichuan Dou Zhuang Liu +8 位作者 Lanling Zhao Jian Zhang Fanpeng Meng Yao Liu Zidong Zhang Xingao Li Zheng Shang Lu Wang Jun Wang 《Nano-Micro Letters》 2026年第2期383-403,共21页
Co_(3)S_(4)electrocatalysts with mixed valences of Co ions and excellent structural stability possess favorable oxygen evolution reaction(OER)activity,yet challenges remain in fabricating rechargeable lithiumoxygen ba... Co_(3)S_(4)electrocatalysts with mixed valences of Co ions and excellent structural stability possess favorable oxygen evolution reaction(OER)activity,yet challenges remain in fabricating rechargeable lithiumoxygen batteries(LOBs)due to their poor OER performance,resulting from poor electrical conductivity and overly strong intermediate adsorption.In this work,fancy double heterojunctions on 1T/2H-MoS_(2)@Co_(3)S_(4)(1T/2H-MCS)were constructed derived from the charge donation from Co to Mo ions,thus inducing the phase transformation of Mo S_(2)from 2H to 1T.The unique features of these double heterojunctions endow the1T/2H-MCS with complementary catalysis during charging and discharging processes.It is worth noting that 1T-Mo S2@Co3S4could provide fast Co-S-Mo electron transport channels to promote ORR/OER kinetics,and 2H-MoS_(2)@Co_(3)S_(4)contributed to enabling moderate egorbital occupancy when adsorbed with oxygen-containing intermediates.On the basis,the Li_(2)O_(2)nucleation route was changed to solution and surface dual pathways,improving reversible deposition and decomposition kinetics.As a result,1T/2H-MCS cathodes exhibit an improved electrocatalytic performance compared with those of Co_(3)S_(4)and Mo S2cathodes.This innovative heterostructure design provides a reliable strategy to construct efficient transition metal sulfide catalysts by improving electrical conductivity and modulating adsorption toward oxygenated intermediates for LOBs. 展开更多
关键词 double heterojunctions d-p hybridization Tunable Li_(2)O_(2)deposition ELECTROCATALYSTS Lithium-oxygen batteries
在线阅读 下载PDF
Towards a Framework for Evaluating the Research Performance of Chinese Double First-Class Universities 被引量:3
13
作者 XU Changqing 《Frontiers of Education in China》 2020年第3期369-402,共34页
The study focuses on the research performance of Double First-Class(DFC)universities in China.A theoretical framework based on economic theory and the Analytic Hierarchy Process(AHP)method for a novel evaluation model... The study focuses on the research performance of Double First-Class(DFC)universities in China.A theoretical framework based on economic theory and the Analytic Hierarchy Process(AHP)method for a novel evaluation model is proposed.The model is performed on a sample of 41 participant DFC universities in China.Using data collected from these universities,it was found that there is no consistency between performance ranking,input ranking,and output ranking,with the best ranked universities far from the most efficient.These findings provide empirical evidence of DFC universities’research performance situation and suggest strategies that the government can use to propel their sustainable development. 展开更多
关键词 double first-class(DFC)university research performance double first-class University Research Performance Evaluation model(DFCuRPE model) evaluation validation
原文传递
基于Double-Double理论的机身结构优化设计
14
作者 郑传祥 宋兆波 +5 位作者 俞轶宸 卢锦杰 荆磊 陈思燃 苏璐 Stephen Tsai 《高科技纤维与应用》 2025年第2期43-50,共8页
Double-Double(下称DD)理论是由斯坦福大学Stephen Tsai教授首先提出,其理论依据是给定材料的复合材料层合板的蔡氏模量为常量,与纤维的敷设角度和铺设顺序无关。利用层合板的这个特点,常用传统的层合板可以用二个角度±φ、±... Double-Double(下称DD)理论是由斯坦福大学Stephen Tsai教授首先提出,其理论依据是给定材料的复合材料层合板的蔡氏模量为常量,与纤维的敷设角度和铺设顺序无关。利用层合板的这个特点,常用传统的层合板可以用二个角度±φ、±ψ的四种组合来替代。如果根据载荷情况对φ、ψ的数值进行优化,则层合板的承载性能可以得到提高;如果采用相同的安全系数,则层数可以减少达到减重的目的。本文以机身研究对象,基于DD理论对机身进行优化设计,通过计算可以发现,相同载荷下,机身重量可以得到较大的减轻。 展开更多
关键词 double-double理论 机身 优化 设计
在线阅读 下载PDF
基于Double Q-Learning的改进蝗虫算法求解分布式柔性作业车间逆调度问题
15
作者 胡旭伦 唐红涛 《机床与液压》 北大核心 2025年第20期52-63,共12页
针对分布式柔性作业车间中存在的资源分配不均和调度稳定性不足问题,构建以最小化最大完工时间、机器总能耗和偏离度为目标的逆调度数学模型,提出一种基于Double Q-Learning的改进多目标蝗虫优化算法(DQIGOA)。针对该问题设计一种混合... 针对分布式柔性作业车间中存在的资源分配不均和调度稳定性不足问题,构建以最小化最大完工时间、机器总能耗和偏离度为目标的逆调度数学模型,提出一种基于Double Q-Learning的改进多目标蝗虫优化算法(DQIGOA)。针对该问题设计一种混合三层编码方式;提出一种基于逆调度特点的种群初始化方式以提高种群质量;引入权重平衡因子来提高非支配解存档中解集的多样性;将强化学习中的Double Q-Learning机制融入非支配解的选择过程,通过动态动作策略优化目标解的选取,提升调度方案的全局搜索能力与局部优化效率。最后构建26组算例,通过策略有效性分析证明了所提策略可显著提升DQIGOA算法的性能,并通过与NSGA-II、DE和SPEA-II算法进行对比证明DQIGOA算法的有效性。结果表明:相比NSGA-II、DE和SPEA-II算法,DQIGOA算法在HV、IGD、SP指标上均有优势,证明了DQIGOA能够有效提升解的收敛速度和多样性分布,在动态扰动条件下表现出更强的鲁棒性。 展开更多
关键词 分布式柔性作业车间 逆调度 蝗虫算法 double Q-Learning机制
在线阅读 下载PDF
Boosting characteristic emissions of lanthanide in Cs_(2)Ag_(0.6)Na_(0.4)InCl_(6-x)Br_(x) double perovskites via mixing halide 被引量:2
16
作者 Shujian Wang Dejian Chen +4 位作者 Jie Hu Sisi Liang Kunyuan Xu Maochun Hong Haomiao Zhu 《Journal of Rare Earths》 2025年第1期39-46,I0002,共9页
Lanthanide ions(Ln^(3+))doping provides a potential strategy to control over the luminescent properties of lead-free halide double perovskite nanocrystals(DP NCs).However,due to the low energy transfer efficiency betw... Lanthanide ions(Ln^(3+))doping provides a potential strategy to control over the luminescent properties of lead-free halide double perovskite nanocrystals(DP NCs).However,due to the low energy transfer efficiency between self-trapped exciton(STE)and Ln^(3+)ions,the characteristic emissions of Ln^(3+)ions are not prominent.Furthermore,the energy transfer mechanism between STE and Ln^(3+)ions is also elusive and requires in-depth study.We chose trace Bi^(3+)-doped Cs_(2)Ag_(0.6)Na_(0.4)InCl_(6-x)Br_(x) as a representative DP matrix to demonstrate that by tuning the bromide concentration,the Ln^(3+)emission can be greatly enhanced.Such enhanced STE and Ln^(3+)ions energy transfer originates from the high covalency of Ln-Br bond,which contributes to improve ment of the characteristic emission of Ln^(3+)ions.Furthermo re,optical spectroscopy reveals that the energy transfer mechanism from DP to Eu^(3+)ions is different from all the other doped Ln^(3+)ions.The energy transfer from DP to Eu^(3+)ions is mostly through Eu-Br charge transfer while the other Ln^(3+)ions are excited by energy transfer from STE.The distinct energy transfer mechanism has resulted from the energy separation between the excited energy level of Ln^(3+)ions and the bottom of conduction band of DP.With increasing the energy separation,the energy transfer from STE to Ln^(3+)ions is less efficient because of the generation of a larger number of phonons and finally becomes impossible for Eu^(3+)ions.Our results provide new insight into tuning the energy transfer of Ln^(3+)-doped DP NCs. 展开更多
关键词 double perovskitenanocrystal Lead free Lanthanideions Energytransfer Rare earths
原文传递
Film thickness effect on 2D lead-free hybrid double perovskite properties: Band gap, photocurrent and stability 被引量:1
17
作者 Mohamed Saber Lassoued Faizan Ahmad Yanzhen Zheng 《Chinese Chemical Letters》 2025年第4期449-454,共6页
Lead-free hybrid double perovskites(LFHDPs) have received a lot of attention due to their environmental friendliness and promising attributes. However, studying the effect of film thickness on LFHDPs optoelectronic pr... Lead-free hybrid double perovskites(LFHDPs) have received a lot of attention due to their environmental friendliness and promising attributes. However, studying the effect of film thickness on LFHDPs optoelectronic properties has not yet been investigated. Herein, we synthesized two new Ruddlesden–Popper LFHDPs, namely(C_(5)H_(12)N)_(4)AgBiI_(8)(CAB-1) and(C_(6)H_(14)N)_(4)Ag Bi I8(CAB-2) using cyclopentylamine and cyclohexylamine as monoamine ligands. Indeed, these two Ag(Ⅰ)-Bi(Ⅲ) LFHDPs form smooth and uniform films ranging in thickness from 250 nm to 1 μm, with preferred orientations. Notably, the studies on the optical properties showed that the direct band gap value decreased from 2.17 e V to 1.91 e V for CAB-1 and from 2.05 e V to 1.86 e V for CAB-2 with increasing thickness. Accordingly, photo-current response using a xenon lamp revealed a significant difference of over 1000 n A between light and dark conditions for1 μm-thickness films, suggesting potential for light harvesting. Other than that, thicker films of CAB-1and CAB-2 exhibit high stability for 90 days in a relatively humid environment(RH of 55%), paving the way for promising optoelectronic applications. 展开更多
关键词 LEAD-FREE double perovskites Film thickness Photocurrent response High stability
原文传递
Optimal Production Capacity Matching for Blockchain-Enabled Manufacturing Collaboration With the Iterative Double Auction Method 被引量:1
18
作者 Ying Chen Feilong Lin +2 位作者 Zhongyu Chen Changbing Tang Cailian Chen 《IEEE/CAA Journal of Automatica Sinica》 2025年第3期550-562,共13页
The increased demand for personalized customization calls for new production modes to enhance collaborations among a wide range of manufacturing practitioners who unnecessarily trust each other.In this article,a block... The increased demand for personalized customization calls for new production modes to enhance collaborations among a wide range of manufacturing practitioners who unnecessarily trust each other.In this article,a blockchain-enabled manufacturing collaboration framework is proposed,with a focus on the production capacity matching problem for blockchainbased peer-to-peer(P2P)collaboration.First,a digital model of production capacity description is built for trustworthy and transparent sharing over the blockchain.Second,an optimization problem is formulated for P2P production capacity matching with objectives to maximize both social welfare and individual benefits of all participants.Third,a feasible solution based on an iterative double auction mechanism is designed to determine the optimal price and quantity for production capacity matching with a lack of personal information.It facilitates automation of the matching process while protecting users'privacy via blockchainbased smart contracts.Finally,simulation results from the Hyperledger Fabric-based prototype show that the proposed approach increases social welfare by 1.4%compared to the Bayesian game-based approach,makes all participants profitable,and achieves 90%fairness of enterprises. 展开更多
关键词 Blockchain iterative double auction manufacturing collaboration production capacity matching
在线阅读 下载PDF
Achievable Rate Analysis and Optimization of Double-RIS Assisted Spatially Correlated MIMO with Statistical CSI 被引量:1
19
作者 Xu Kaizhe Guo Jiajia +2 位作者 Zhang Jun Jin Shi Ma Shaodan 《China Communications》 2025年第1期139-157,共19页
Reconfigurable intelligent surface(RIS)is a novel meta-material which can form a smart radio environment by dynamically altering reflection directions of the impinging electromagnetic waves.In the prior literature,the... Reconfigurable intelligent surface(RIS)is a novel meta-material which can form a smart radio environment by dynamically altering reflection directions of the impinging electromagnetic waves.In the prior literature,the inter-RIS links which also contribute to the performance of the whole system are usually neglected when multiple RISs are deployed.In this paper we investigate a general double-RIS assisted multiple-input multiple-output(MIMO)wireless communication system under spatially correlated non line-of-sight propagation channels,where the cooperation of the double RISs is also considered.The design objective is to maximize the achievable ergodic rate based on full statistical channel state information(CSI).Specifically,we firstly present a closedform asymptotic expression for the achievable ergodic rate by utilizing replica method from statistical physics.Then a full statistical CSI-enabled optimal design is proposed which avoids high pilot training overhead compared to instantaneous CSI-enabled design.To further reduce the signal processing overhead and lower the complexity for practical realization,a common-phase scheme is proposed to design the double RISs.Simulation results show that the derived asymptotic ergodic rate is quite accurate even for small-sized antenna arrays.And the proposed optimization algorithm can achieve substantial gain at the expense of a low overhead and complexity.Furthermore,the cooperative double-RIS assisted MIMO framework is proven to achieve superior ergodic rate performance and high communication reliability under harsh propagation environment. 展开更多
关键词 common reflection pattern double RISs large system analysis MIMO replica method
在线阅读 下载PDF
Multicomponent Gd_(1−x)Sm_(x)Ba_(0.5)Sr_(0.5)CoCuO_(5+δ) double perovskites as oxygen electrodes for solid oxide cells:Effect of chemical composition and electrospun morphology 被引量:1
20
作者 Jacek Winiarski Piotr Winiarz Konrad Świerczek 《International Journal of Minerals,Metallurgy and Materials》 2025年第11期2628-2638,共11页
Multicomponent Gd_(1−x)Sm_(x)Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)double perovskites are optimized for application in terms of chemical composi-tion and morphology for the use as oxygen electrodes in solid oxide cells.Structur... Multicomponent Gd_(1−x)Sm_(x)Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)double perovskites are optimized for application in terms of chemical composi-tion and morphology for the use as oxygen electrodes in solid oxide cells.Structural studies of other physicochemical properties are con-ducted on a series of materials obtained by the sol-gel method with different ratios of Gd and Sm cations.It is documented that changing the x value,and the resulting adjustment of the average ionic radius,have a significant impact on the crystal structure,stability,as well as on the total conductivity and thermomechanical properties of the materials,with the best results obtained for the Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)composition.Oxygen electrodes are prepared using the selected compound,allowing to obtain low polarization resistance values,such as 0.086Ω·cm^(2)at 800℃.Systematic studies of electrocatalytic activity are conducted using La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(_(0.2))O_(3−δ)as the electrolyte for all electrodes,and Ce_(0.8)Gd_(0.2)O_(2−δ)electrolyte for the best performing Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)electrodes.The electrochemical data are analyzed using the distribution of relaxation times method.Also,the influence of the preparation method of the electrode material is in-ve`stigated using the electrospinning technique.Finally,the performance of the Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)electrodes is tested in a Ni-YSZ(yttria-stabilized zirconia)anode-supported cell with a Ce_(0.8)Gd_(0.2)O_(2−δ)buffer layer,in the fuel cell and electrolyzer operating modes.With the electrospun electrode,a power density of 462 mW·cm^(−2)is obtained at 700℃,with a current density of ca.0.2 A·cm^(−2)at 1.3 V for the electrolysis at the same temperature,indicating better performance compared to the sol-gel-based electrode. 展开更多
关键词 multicomponent oxides double perovskites morphology modification ELECTROSPINNING oxygen electrodes solid oxide cells
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部