检索结果-南通市图书馆

Dynamic Routing of Multiple QoS-Required Flows in Cloud-Edge Autonomous Multi-Domain Data Center Networks

Computers, Materials & Continua 2024年第2期78卷 2287-2308页

作者： Shiyan Zhang ruohan Xu Zhangbo Xu Cenhua yu yuyang Jiang yuting Zhao School of Computer Science(National Pilot Software Engineering School) Beijing University of Posts and TelecommunicationsBeijing100876China College of Computer Science and Technology Tianjin UniversityTianjin300072China Institute of Artificial Intelligence Nankai UniversityTianjin300071China College of Information Science and Engineering East China University of Science and TechnologyShanghai200237China

The 6th generation mobile networks(6G)network is a kind of multi-network interconnection and multi-scenario coexistence network,where multiple network domains break the original fixed boundaries to form connections and convergence.In this paper,with the optimization objective of maximizing network utility while ensuring flows performance-centric weighted fairness,this paper designs a reinforcement learning-based cloud-edge autonomous multi-domain data center network architecture that achieves single-domain autonomy and multi-domain collaboration.Due to the conflict between the utility of different flows,the bandwidth fairness allocation problem for various types of flows is formulated by considering different defined reward functions.Regarding the tradeoff between fairness and utility,this paper deals with the corresponding reward functions for the cases where the flows undergo abrupt changes and smooth changes in the flows.In addition,to accommodate the Quality of Service(QoS)requirements for multiple types of flows,this paper proposes a multi-domain autonomous routing algorithm called LSTM+MADDPG.Introducing a Long Short-Term Memory(LSTM)layer in the actor and critic networks,more information about temporal continuity is added,further enhancing the adaptive ability changes in the dynamic network environment.The LSTM+MADDPG algorithm is compared with the latest reinforcement learning algorithm by conducting experiments on real network topology and traffic traces,and the experimental results show that LSTM+MADDPG improves the delay convergence speed by 14.6%and delays the start moment of packet loss by 18.2%compared with other algorithms.

关键词： Multi-Domain data center networks autonomous routing

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

Single-Atom Lithiophilic Sites Confined within Ordered Porous Carbon for Ultrastable Lithium Metal Anodes

引用

Energy & Environmental Materials 2023年第3期6卷 366-372页

作者： Wenzhong Huang Shanlin Liu ruohan yu Liang Zhou Zhenhui Liu Liqiang Mai State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Nanostructure Research Centre Wuhan University of TechnologyWuhan 430070China College of Material Science and Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory Xianhu hydrogen ValleyFoshan 528200China

Attributing to the high specific capacity and low electrochemical reduction potential,lithium(Li)metal is regarded as the most promising anode for high-energy Li batteries.However,the growth of lithium dendrites and huge volume change seriously limit the development of lithium metal batteries.To overcome these challenges,an ordered mesoporous N-doped carbon with lithiophilic single atoms is proposed to induce uniform nucleation and deposition of Li metal.Benefiting from the synergistic effects of interconnected three-dimensional ordered mesoporous structures and abundant lithiophilic single-atom sites,regulated local current density and rapid mass transfer can be achieved,leading to the uniform Li deposition with inhibition of dendrites and buffered volume expansion.As a result,the as-fabricated anode exhibits a high CE of 99.8%for 200 cycles.A stable voltage hysteresis of 14 mV at 5 mA cm^(−2)could be maintained for more than 1330 h in the symmetric cell.Furthermore,the full cell coupled with commercial LiFePO_(4)exhibits high reversible capacity of 108 mAh g^(−1)and average Coulombic efficiency of 99.8%from 5th to 350th cycles at 1 C.The ordered mesoporous carbon host with abundant lithiophilic single-atom sites delivers new inspirations into rational design of high-performance Li metal anodes.

关键词： lithiophilic lithium metal battery ordered mesoporous carbon single atom

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

Transformation of Undesired Li_(2)CO_(3)into Lithiophilic Layer Via Double Replacement Reaction for Garnet Electrolyte Engineering

引用

Energy & Environmental Materials 2022年第3期5卷 962-968页

作者： Jiaxu Zhang ruohan yu Jun Li Huiyu Zhai Gangjian Tan Xinfeng Tang State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China International School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China

Garnet-type solid-state electrolytes(SSEs)are a remarkable Li-ion electrolyte for the realization of next-generation all-solid-state lithium batteries due to their excellent stability against Li metal as well as high ionic conductivities at room temperature.However,garnet electrolytes always contain undesired and hardly removable Li_(2)CO_(3) contaminations that have persistently large resistance and unstable interface contact with Li metal.This is a critical bottleneck for the practical application of garnet electrolytes.Here,we design a novel strategy to completely root out Li_(2)CO_(3) both inside and on the surface of garnet.This is achieved by a so-called double replacement reaction between Li_(2)CO_(3) and SiO_(2) during one-step hot press process for garnet electrolyte densification.It leads to in-situ transformation of LixSiOy(LSO)mostly locating around the grain boundaries of garnet.Due to the higher ion conductivity and better electrochemistry stability of LSO than Li_(2)CO_(3),the modified garnet electrolyte shows much improved electrochemical performance.Moreover,the wettability between modified garnet electrolyte and lithium metals was significantly enhanced in the absence of surface Li_(2)CO_(3).As a proof of concept,an assembled Li symmetric cell with modified garnet electrolyte displays a high critical current density(CCD)of 0.7 mA cm^(-2)and a low interfacial impedance(5Ωcm^(2))at 25℃.These results indicate that the upcycling of Li_(2)CO_(3)is a promising strategy to well-address the degradation and interfacial issue associated with garnet electrolytes.

关键词： double replacement reaction garnet electrolytes lithiophilic layer solid-state lithium batteries

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

Unraveling the reaction mechanisms of electrode materials for sodiumion and potassium‐ion batteries by in situ transmission electron microscopy

引用

Interdisciplinary Materials 2022年第2期1卷 196-212页

作者： Hong Wang Fang Liu ruohan yu Jinsong Wu Nanostructure Research Center(NRC) Wuhan University of TechnologyWuhanHubeiChina State Key Laboratory of Advanced Technology for Materials Synthesis and Processing School of Materials Science and EngineeringWuhan University of TechnologyWuhanHubeiChina School of Mathematics and Physics Jingchu University of TechnologyJingmenHubeiChina

Sodium ion batteries(SIBs)and potassium ion batteries(PIBs)have caught numerous attention due to the low cost and abundant availability of sodium and potassium.However,their power density,cycling stability and safety need further improvement for practical applications.Investigations on the reaction mechanisms and structural degradation when cycling are of great importance.In situ transmission electron microscopy(TEM)is one of the most significant techniques to understand and monitor electrochemical processes at an atomic scale with real-time imaging.In this review,the current progress in unraveling reaction mechanisms of electrode materials for SIBs and PIBs via in situ TEM is summarized.First,the importance of in situ TEM is highlighted.Then,based on the three types of electrochemical reaction,i.e.,intercalation reac-tion,conversion reaction and alloying reaction,the structural evolution and reaction kinetics at atomic resolution,and their relation to the electrochemical performance of electrode materials are reviewed and described in detail.Fi-nally,future directions of in situ TEM for SIBs and PIBs are proposed.Therefore,the in‐depth understanding revealed by in situ TEM will give an instructive guide in rational design of electrode materials for high performance electrode materials of SIBs and PIBs.

关键词： in situ transmission electron microscopy potassium ion batteries sodiumion batteries

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

Chemical cross-linking and mechanically reinforced carbon network constructed by graphene boosts potassium ion storage

引用

Nano Research 2022年第10期15卷 9019-9025页

作者： Chenxu Wang ruohan yu Wen Luo Wencong Feng yuanhao Shen Nuo Xu Liqiang Mai Department of Physics School of ScienceWuhan University of TechnologyWuhan 430070China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology430070 WuhanChina Nanostructure Research Centre(NRC) Wuhan University of TechnologyWuhan 430070China

Carbon-based electrodes of potassium-ion batteries are of great research interest ascribed to their low cost and environmentally friendly distinctions.However,traditional carbon materials usually exhibit weak mechanical properties and incomplete crosslinking,resulting in poor stability and electrochemical performance.Herein,we report a new strategy for modifying reduced graphene oxide into a uniform few-layer structure through a sol–gel method combined with acid etching treatment.The obtained chemical cross-linking and mechanically reinforced carbon network constructed by graphene(CNCG)demonstrates excellent electrochemical and mechanical properties.Adopted as a free-standing anode(~7 mg·cm^(−2))for potassium ion battery,the asachieved CNCG delivers a high reversible specific capacity of 317.7 mAh·g^(−1) at a current density of 50 mA·g^(−1) and admirable cycle stability(208.4 mAh·g^(−1) at 50 mA·g^(−1) after 500 cycles).The highly reversible structural stability and fully cross-linked properties during potassiation are revealed by ex-situ characterization.This work provides new ideas for the synthesis of new carbon materials and the development of high-performance electrodes.

关键词： potassium-ion battery graphene electrode chemical cross-linking mechanical property storage mechanism

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

Tuning Active Metal Atomic Spacing by Filling of Light Atoms and Resulting Reversed Hydrogen Adsorption-Distance Relationship for Efficient Catalysis

引用

Nano-Micro Letters 2023年第10期15卷 151-162页

作者： Ding Chen Ruihu Lu ruohan yu Hongyu Zhao Dulan Wu Youtao Yao Kesong yu Jiawei Zhu Pengxia Ji Zonghua Pu Zongkui Kou Jun yu Jinsong Wu Shichun Mu State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070People’s Republic of China NRC(Nanostructure Research Centre) Wuhan University of TechnologyWuhan 430070People’s Republic of China

Precisely tuning the spacing of the active centers on the atomic scale is of great significance to improve the catalytic activity and deepen the understanding of the catalytic mechanism,but still remains a challenge.Here,we develop a strategy to dilute catalytically active metal interatomic spacing(d_(M-M))with light atoms and discover the unusual adsorption patterns.For example,by elevating the content of boron as interstitial atoms,the atomic spacing of osmium(d_(Os-Os))gradually increases from 2.73 to 2.96?.More importantly,we find that,with the increase in dOs-Os,the hydrogen adsorption-distance relationship is reversed via downshifting d-band states,which breaks the traditional cognition,thereby optimizing the H adsorption and H_2O dissociation on the electrode surface during the catalytic process;this finally leads to a nearly linear increase in hydrogen evolution reaction activity.Namely,the maximum dOs-Os of 2.96?presents the optimal HER activity(8 mV@10 mA cm^(-2))in alkaline media as well as suppressed O adsorption and thus promoted stability.It is believed that this novel atomic-level distance modulation strategy of catalytic sites and the reversed hydrogen adsorption-distance relationship can shew new insights for optimal design of highly efficient catalysts.

关键词： Electrocatalysis DFT calculation Interstitial filling Hydrogen evolution Structure–activity relationships

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

Bi nanoparticles encapsulated in nitrogen-doped carbon as a long-life anode material for magnesium batteries

引用

Journal of Magnesium and Alloys 2023年第11期11卷 4181-4188页

作者： Junjun Wang ruohan yu Jianxiang Wang Juncai Long Fan Qiao Lei Zhang Guanjie He Qinyou An Liqiang Mai State Key Laboratory of Advanced Technology for Materials Synthesis and Processing School of Materials Science and EngineeringWuhan University of TechnologyWuhan 430070China Christopher Ingold Laboratory Department of ChemistryUniversity College London20 Gordon StreetLondon WC1H 0AJUnited Kingdom of Great Britain and Northern IrelandUnited Kingdom Hubei Longzhong Laboratory Wuhan University of Technology(Xiangyang Demonstration Zone)Xiangyang 441000China

Bismuth has garnered significant interest as an anode material for magnesium batteries(MBs) because of its high volumetric specific capacity and low working potential. Nonetheless, the limited cycling performance(≤100 cycles) limits the practical application of Bi as anode for MBs. Therefore, the improvement of Bi cycling performance is of great significance to the development of MBs and is also full of challenges. Here, Bi nanoparticles encapsulated in nitrogen-doped carbon with single-atom Bi embedded(Bi@NC) are prepared and reported as an anode material for MBs. Bi@NC demonstrates impressive performance, with a high discharge capacity of 347.5 mAh g^(-1) and good rate capability(206.4 mAh g^(-1)@500 mA g^(-1)) in a fluoride alkyl magnesium salt electrolyte. In addition, Bi@NC exhibits exceptional long-term stability, enduring 400 cycles at 500 mA g^(-1). To the best of our knowledge, among reported Bi and Bi-based compounds for MBs, Bi@NC exhibits the longest cycle life in this work. The magnesium storage mechanism of Bi@NC is deeply studied through X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. This work provides some guidance for further improving the cycling performance of other alloy anodes in MBs.

关键词： Magnesium batteries Bismuth 3D tomography reconstruction Magnesium alloy Single-atom

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

Rational protein engineering of thermostable heparinase I from Bacteroides thetaiotaomicron for highly efficient heparin degradation

引用

Food Science and Human Wellness 2024年

作者： Chuan Zhang ruohan Zhao Leilei yu Qixiao Zhai Jianxin Zhao Hao Zhang Xuegang Luo Fengwei Tian Wei Chen State Key Laboratory of Food Science and Technology Jiangnan University School of Food Science and Technology Jiangnan University Key Laboratory of Industrial Fermentation Microbiology of the Ministry of Education & Tianjin Key Lab of Industrial Microbiology College of Biotechnology Tianjin University of Science and Technology National Engineering Research Center for Functional Food Jiangnan University

Heparin， a glycosaminoglycan， is a stable source of carbon that supports the growth of microorganisms in the human intestine. It is also a commonly used anticoagulant drug in clinical practice， with significant therapeutic effects. Low molecular weight heparin （LMWH） is a highly active low molecular weight fragment obtained via enzymatic reaction or the chemical degradation of heparin. LMWH has been applied globally in the prevention and treatment of venous thromboembolism in thrombosis patients. Simultaneously， as a potential prebiotic， because of its low molecular weight， LMWH can be well degraded by the gut microbiota to maintain intestinal balance. Enzymatic heparin degradation has recently emerged as a viable disposal method for LMWH preparation; however， only very few benchmark enzymes have been thoroughly described and subjected to protein engineering to improve their properties over the past few years. The commercialization of enzymes will require the development of robustly engineered enzymes that meet the demands of industrial processes. Herein， we report a rational protein engineering strategy that includes molecular dynamic simulations of flexible amino acid mutations and disulfide bond screening. Several Bt-HepI mutants were obtained and screened for high thermal stability. We obtained the Bt-HepID204C/K208C/H189W/Q198Rvariant， which features a stabilized protein surface structure， with a 1.3-fold increase in kcat/Km， a 2.44-fold increase in thermal stability at 50℃， and a 1.8-fold decrease in the average molecular weight of LMWH produced at 40℃ compared with that seen with Bt-HepIWT. Our study establishes a strategy to engineer thermostable HepI to underpin its industrial applications.

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

Activating Inert Sites in Cobalt Silicate Hydroxides for Oxygen Evolution through Atomically Doping

引用

Energy & Environmental Materials 2022年第2期5卷 655-661页

作者： Jiexin Zhu Lixue Xia Wenxuan Yang ruohan yu Wei Zhang Wen Luo yuhang Dai Wei Wei Liang Zhou Yan Zhao Liqiang Mai State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China International School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory Xianhu Hydrogen ValleyFoshan 528200China

Metal silicate hydroxides have been recognized as efficient oxygen evolution reaction(OER)electrocatalysts,yet tailoring of their intrinsic activity remains confused.Herein,Fe had been incorporated into cobalt silicate hydroxide nanosheets and the resulted material achieves a competitive OER catalytic activity.It is found that the doping state obviously affects the electrical transport property.Specifically,highly dispersed Fe atoms(low-concentration Fe doping)trigger slight electron transfer to Co atoms while serried Fe(highconcentration Fe doping)attract vast electrons.By introducing 6 at.%Fe doping,partial relatively inert Co sites are activated by atomically dispersed Fe,bearing an optimal metal 3d electronic occupation and adsorption capacity to oxygen intermediate.The introduced Co-O-Fe unit trigger the p-donation effect and decrease the number of electrons in p*-antibonding orbitals,which enhance the Fe-O covalency and the structural stability.As a result,the sample delivers a low overpotential of 293 mV to achieve a current density of 10 mA cm^(-2).This work clarifies the superiority of atomically dispersed doping state,which is of fundamental interest to the design of doped catalyst.

关键词： atomically doping electrochemistry electron transfer metal silicate hydroxides oxygen evolution

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

Photoexcitation-induced passivation of SnO2 thin film for efficient perovskite solar cells

引用

National Science Review 2023年第11期10卷 183-191页

作者： Nianyao Chai Xiangyu Chen Zhongle Zeng ruohan yu yunfan yue Bo Mai Jinsong Wu Liqiang Mai Yi-Bing Cheng Xuewen Wang State Key Laboratory of Advanced Technology for Materials Synthesis and Processing International School of Materials Science and EngineeringWuhan University of Technology National Energy Key Laboratory for New Hydrogen-Ammonia Energy Technologies Foshan Xianhu Laboratory

A high-quality tin oxide electron transport layer(ETL) is a key common factor to achieve high-performance perovskite solar cells(PSCs). However, the conventional annealing technique to prepare high-quality ETLs by continuous heating under near-equilibrium conditions requires high temperatures and a long fabrication time. Alternatively, we present a non-equilibrium, photoexcitation-induced passivation technique that uses multiple ultrashort laser pulses. The ultrafast photoexcitation and following electron–electron and electron–phonon scattering processes induce ultrafast annealing to efficiently passivate surface and bulk defects, and improve the crystallinity of Sn O2, resulting in suppressing the carrier recombination and facilitating the charge transport between the ETL and perovskite interface. By rapidly scanning the laser beam, the annealing time is reduced to several minutes, which is much more efficient compared with conventional thermal annealing. To demonstrate the university and scalability of this technique, typical antisolvent and antisolvent-free processed hybrid organic–inorganic metal halide PSCs have been fabricated and achieved the power conversion efficiency(PCE) of 24.14% and 22.75% respectively, and a12-square-centimeter module antisolvent-free processed perovskite solar module achieves a PCE of 20.26%,with significantly enhanced performance both in PCE and stability. This study establishes a new approach towards the commercialization of efficient low-temperature manufacturing of PSCs.

关键词： photoexcitation-induced passivation ultrafast laser carrier management electron transport layer perovskite solar cells

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：