检索结果-南通市图书馆

Exploration of the oxygen transport behavior in non-precious metal catalyst-based cathode catalyst layer for proton exchange membrane fuel cells

引用

Frontiers in Energy 2023年第1期17卷 123-133页

作者： Shiqu CHEN silei xiang Zehao TAN Huiyuan LI Xiaohui YAN Jiewei YIN Shuiyun SHEN Junliang ZHANG Institute of Fuel Cells School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Vehicle and Mobility State Key Laboratory of Automotive Safety and EnergyTsinghua UniversityBeijing 100084China

High cost has undoubtedly become the biggest obstacle to the commercialization of proton exchange membrane fuel cells(PEMFCs),in which Pt-based catalysts employed in the cathodic catalyst layer(CCL)account for the major portion of the *** nonprecious metal catalysts(NPMCs)show appreciable activity and stability in the oxygen reduction reaction(ORR),the performance of fuel cells based on NPMCs remains unsatisfactory compared to those using Pt-based ***,most studies on NPMC-based fuel cells focus on developing highly active catalysts rather than facilitating oxygen *** this work,the oxygen transport behavior in CCLs based on highly active Fe-N-C catalysts is comprehensively explored through the elaborate design of two types of membrane electrode structures,one containing low-Pt-based CCL and NPMCbased dummy catalyst layer(DCL)and the other containing only the NPMC-based *** Zn-N-C based DCLs of different thickness,the bulk oxygen transport resistance at the unit thickness in NPMC-based CCL was quantified via the limiting current method combined with linear fitting ***,the local and bulk resistances in NPMC-based CCLs were quantified via the limiting current method and scanning electron microscopy,*** show that the ratios of local and bulk oxygen transport resistances in NPMCbased CCL are 80%and 20%,respectively,and that an enhancement of local oxygen transport is critical to greatly improve the performance of NPMC-based ***,the activity of active sites per unit in NPMCbased CCLs was determined to be lower than that in the Pt-based CCL,thus explaining worse cell performance of NPMC-based membrane electrode assemblys(MEAs).It is believed that the development of NPMC-based PEMFCs should proceed not only through the design of catalysts with higher activity but also through the improvement of oxygen transport in the CCL.

关键词： proton exchange membrane fuel cells(PEMFCs) non-precious metal catalyst(NPMC) cathode catalyst layer(CCL) local and bulk oxygen transport resistance

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

基于MOFs材料的非贵金属氧还原电催化剂研究进展

引用

中国科学：技术科学 2022年第3期52卷 375-388页

作者：任子文谭泽昊向思磊陈士渠沈水云章俊良上海交通大学机械与动力工程学院燃料电池研究所上海200240 上海交通大学动力机械与工程教育部重点实验室上海200240

质子交换膜燃料电池(PEMFCs)因具有清洁、高效、安静、功率密度高、工作温度低、启动和功率匹配快等优点在新能源汽车领域备受青睐.由于PEMFCs阴极使用高载量的铂(Pt)基催化剂,其成本一直居高不下,大大阻碍了燃料电池汽车商业化进程.开... 详细信息

质子交换膜燃料电池(PEMFCs)因具有清洁、高效、安静、功率密度高、工作温度低、启动和功率匹配快等优点在新能源汽车领域备受青睐.由于PEMFCs阴极使用高载量的铂(Pt)基催化剂,其成本一直居高不下,大大阻碍了燃料电池汽车商业化进程.开发替代的高活性、高稳定性非贵金属催化剂被认为是终极解决方案.在众多类型的非贵金属催化剂中,碳-氮-过渡金属系列非贵金属催化剂表现出的ORR活性和寿命尤其值得关注.基于金属有机框架材料(MOFs)的非贵金属ORR电催化剂具有优异的性能而被广泛研究.本文通过介绍MOFs材料的特点与优势,综述了近年来国内外基于MOFs材料的碳-氮-过渡金属ORR电催化剂研究现状,主要包括Fe基MOFs催化剂、Co基MOFs催化剂、双金属MOFs催化剂等,并针对研究中遇到的瓶颈与挑战进行分析与展望,指出未来需要面向膜电极的活性、稳定性等进行深入研究.

关键词：燃料电池催化剂氧化金属有机框架化合物质子交换膜

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

Mitophagy in acute central nervous system injuries:regulatory mechanisms and therapeutic potentials

引用

Neural Regeneration Research 2025年第9期20卷 2437-2453页

作者： Siyi Xu Junqiu Jia Rui Mao xiang Cao Yun Xu Department of Neurology Nanjing Drum Tower HospitalClinical College of Jiangsu UniversityNanjingJiangsu ProvinceChina Department of Neurology Nanjing Drum Tower HospitalChinese Academy of Medical Science&Peking Union Medical CollegeNanjingJiangsu ProvinceChina Department of Neurology Nanjing Drum Tower HospitalAffiliated Hospital of Medical SchoolNanjing UniversityNanjingJiangsu ProvinceChina State Key Laboratory of Pharmaceutical Biotechnology and Institute of Translational Medicine for Brain Critical Diseases Nanjing UniversityNanjingJiangsu ProvinceChina Jiangsu Key Laboratory for Molecular Medicine Medical School of Nanjing UniversityNanjingJiangsu ProvinceChina Nanjing Neurology Medical Center NanjingJiangsu ProvinceChina

Acute central nervous system injuries,including ischemic stro ke,intracerebral hemorrhage,subarachnoid hemorrhage,traumatic brain injury,and spinal co rd injury,are a major global health *** optimal therapies and improving the long-term neurological functions of patients with acute central nervous system injuries are urgent *** are susceptible to damage after acute central nervous system injury,and this leads to the release of toxic levels of reactive oxygen species,which induce cell ***,a selective form of autophagy,is crucial in eliminating redundant or damaged mitochondria during these *** evidence has highlighted the significant role of mitophagy in acute central nervous system *** this review,we provide a comprehensive overview of the process,classification,and related mechanisms of *** also highlight the recent developments in research into the role of mitophagy in various acute central nervous system injuries and drug therapies that regulate *** the final section of this review,we emphasize the potential for treating these disorders by focusing on mitophagy and suggest future research paths in this area.

关键词： autophagy intracerebral hemorrhage ischemic stroke mitochondria mitochondrial biogenesis mitochondrial quality control mitophagy spinal cord injury subarachnoid hemorrhage traumatic brain injury

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

Investigation of bubbles escape behavior from low basicity mold flux for high-Mn high-Al steels using 3D X-ray microscope

引用

International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 102-110页

作者： Qiang Liu xiang Li Shen Du Ming Gao Yanbin Yin Jiongming Zhang State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the *** which,the behavior of bubbles traversing the liquid slag serves as a restrictive link,closely associated with viscosity and the thickness of liquid *** contrast to two-dimensional surface observation,three-dimensional(3D)analysis method can offer a more intuitive,accurate,and comprehensive ***,this study employs a 3D X-ray microscope(3D-XRM)to obtained spatial distribution and 3D morphological characteristics of residual bubbles in mold flux under different basicity of liquid slag,different temperatures,and different holding *** results indicate that as basicity of slag increases from 0.52 to 1.03,temperature increases from 1423 to 1573 K,the viscosity of slag decreases,the floating rate of bubbles *** addition,when holding time increases from 10 to 30 s,the bubbles floating distance increases,and the volume fraction and average equivalent sphere diameter of the bubbles solidified in the mold flux gradually *** one word,increasing the basicity,temperature,and holding time leading to an increase in the removal rate of bubbles especially for the *** findings of bubbles escape behavior provide valuable insights into optimizing low basicity mold flux for high-Mn high-Al steels.

关键词： mold flux low basicity bubbles three-dimensional X-ray microscope viscosity

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

Quantum public-key crypto via EPR pairs

引用

Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 58-63页

作者： xiang-Qun Fu Hong-Wei Li Jian-Hong Shi Tan Li Wan-Su Bao Henan Key Laboratory of Quantum Information and Cryptography Information Engineering University Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of China

With the development of quantum computing technology, quantum public-key cryptography is gradually becoming an alternative to the existing classical public-key cryptography. This paper designs a quantum trapdoor one-way function via EPR pairs and quantum measurements. Based on this, a new quantum public-key cryptosystem is presented, which offers forward security,and can resist the chosen-plaintext attack and chosen-ciphertext attack. Compared with the existing quantum public-key cryptos,eavesdropping can be automatically detected in this new quantum public-key cryptosystem under a necessary condition, which is also detailed in the paper.

关键词： quantum public-key crypto trapdoor one-way function EPR pairs

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Observation of acoustic hybrid topological phases induced by the p-d orbital interactions

引用

Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 132-139页

作者： Xiao xiang Feng Gao Yu-Gui Peng Peng Wu Zong-Lin Li Xue-Feng Zhu School of Physics and Innovation Institute Huazhong University of Science and Technology

In spinless systems,growing attention has recently been attracted to synthetic gauge fields,which redefine the fundamental crystal symmetries by utilizing the projective algebraic ***,synthetic gauge fields have been commonly investigated in single orbital systems,and explorations on hybrid orbitals remain elusive in ***,we report the experimental observation of hybrid topological phases induced by hybrid synthetic gauge flux,which is formed by the interaction between p and d orbitals embedded in acoustic *** breaking the translation symmetries of Lxand/or Ly,we unambiguously demonstrate the first-order M?bius edge states and higher-order corner *** work establishes a platform for seeking exotic topological phases induced by hybrid-orbitals interactions and initializing the framework of hybrid-orbitalsrelated topological *** applications can be anticipated in scenarios such as high-quality sensing and robust wave trapping due to the stepwise energy distribution of the hybrid topological phase.

关键词： topological insulator synthetic gauge field projective symmetry corner states

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Dispatchable Capability of Aggregated Electric Vehicle Charging in Distribution Systems

引用

Energy Engineering 2025年第1期122卷 129-152页

作者： ShiqianWang Bo Liu Yuanpeng Hua Qiuyan Li Binhua Tang Jianshu Zhou Yue xiang Economic and Technology Research Institute State Grid Henan Electric Power CompanyZhengzhou450052China College of Electrical Engineering Sichuan UniversityChengdu610065China

This paper introduces a method for modeling the entire aggregated electric vehicle(EV)charging process and analyzing its dispatchable *** methodology involves developing a model for aggregated EV charging at the charging station level,estimating its physical dispatchable capability,determining its economic dispatchable capability under economic incentives,modeling its participation in the grid,and investigating the effects of different scenarios and EV penetration on the aggregated load dispatch and dispatchable *** results indicate that using economic dispatchable capability reduces charging prices by 9.7%compared to physical dispatchable capability and 9.3%compared to disorderly ***,the peak-to-valley difference is reduced by 64.6%when applying economic dispatchable capability with 20%EV penetration and residential base load,compared to disorderly charging.

关键词： Aggregated charging dispatchable capability peak shaving and valley filling the economics of charging demand response

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

Liposomes as versatile agents for the management of traumatic and nontraumatic central nervous system disorders:drug stability,targeting efficiency,and safety

引用

Neural Regeneration Research 2025年第7期20卷 1883-1899页

作者： Mingyu Zhang Chunyu xiang Renrui Niu Xiaodong He Wenqi Luo Wanguo Liu Rui Gu Department of Orthopedic Surgery China-Japan Union Hospital of Jilin UniversityChangchunJilin ProvinceChina

Various nanoparticle-based drug delivery systems for the treatment of neurological disorders have been widely ***,their inability to cross the blood–brain barrier hampers the clinical translation of these therapeutic *** are nanoparticles composed of lipid bilayers,which can effectively encapsulate drugs and improve drug delivery across the blood–brain barrier and into brain tissue through their targeting and ***,they can potentially treat traumatic and nontraumatic central nervous system *** this review,we outlined the common properties and preparation methods of liposomes,including thin-film hydration,reverse-phase evaporation,solvent injection techniques,detergent removal methods,and microfluidics ***,we comprehensively discussed the current applications of liposomes in central nervous system diseases,such as Alzheimer's disease,Parkinson's disease,Huntington's disease,amyotrophic lateral sclerosis,traumatic brain injury,spinal cord injury,and brain *** studies related to liposomes are still in the laboratory stage and have not yet entered clinical ***,their application as drug delivery systems in clinical practice faces challenges such as drug stability,targeting efficiency,and ***,we proposed development strategies related to liposomes to further promote their development in neurological disease research.

关键词： Alzheimer's disease amyotrophic lateral sclerosis brain tumors central nervous system Huntington's disease liposome drug delivery neurological disorders Parkinson's disease spinal cord injury traumatic brain injury

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

Gut microbiota in cancer initiation,development and therapy

引用

Science China Life Sciences 2025年

作者： Ruyi Zhang xiang Zhang Harry Cheuk Hay Lau Jun Yu Institute of Digestive Disease and Department of Medicine and Therapeutics State Key Laboratory of Digestive DiseaseLi Ka Shing Institute of Health SciencesCUHK Shenzhen Research InstituteThe Chinese University of Hong Kong

Cancer has long been associated with genetic and environmental factors,but recent studies reveal the important role of gut microbiota in its initiation and *** 13%of cancers are linked to infectious agents,highlighting the need to identify the specific microorganisms *** microbiota can either promote or inhibit cancer growth by influencing oncogenic signaling pathways and altering immune *** can lead to cancer,while certain probiotics and their metabolites may help reestablish microecological balance and improve anti-tumor immune *** into targeted approaches that enhance therapy with probiotics is ***,the effects of probiotics in humans are complex and not yet fully ***,methods to counteract harmful bacteria are still in *** clinical trials also indicate that modifying gut microbiota may help manage side effects of cancer *** research is crucial to understand better how gut microbiota can be used to improve cancer prevention and treatment outcomes.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Cross-subcarrier precoder design for massive MIMO-OFDM downlink with symplectic optimization

引用

Science China(Information Sciences) 2025年

作者： Yu-Xuan ZHANG An-An LU xiang-Gen XIA Xi-Qi GAO National Mobile Communications Research Laboratory Southeast University Purple Mountain Laboratories Department of Electrical and Computer Engineering University of Delaware

We propose a cross-subcarrier precoder design(CSPD) for massive multiple-input multiple-output(MIMO) orthogonal frequency division multiplexing(OFDM) downlink. This work aims to significantly improve the channel estimation and signal detection performance by enhancing the smoothness of the frequency domain effective channel. This is accomplished by designing a few vectors known as the transform domain precoding vectors(TDPVs), which are then transformed into the frequency domain to generate the precoders for a set of subcarriers. To combat the effect of channel aging, the TDPVs are optimized under imperfect channel state information(CSI). The optimal precoder structure is derived by maximizing an upper bound of the ergodic weighted sum-rate(WSR) and utilizing the a posteriori beam-based statistical channel model(BSCM). To avoid the large-dimensional matrix inversion, we propose an algorithm with symplectic optimization. Simulation results indicate that the proposed cross-subcarrier precoder design significantly outperforms conventional methods.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

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：