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Journal of Computational Mathematics 2024年第2期42卷 415-431页

作者： Yanmi wu Dongyang shi PLA Information Engineering University Zhengzhou 450001China School of Mathematics and Information Sciences Yantai UniversityYantai 264005China

In this paper,a two-grid mixed finite element method(MFEM)of implicit Backward Euler(BE)formula is presented for the fourth order time-dependent singularly perturbed Bi-wave problem for d-wave superconductors by the nonconforming EQ_(1)^(rot) *** this approach,the original nonlinear system is solved on the coarse mesh through the Newton iteration method,and then the linear system is computed on the fine mesh with Taylor’s *** on the high accuracy results of the chosen element,the uniform superclose and superconvergent estimates in the broken H^(1)-norm are derived,which are independent of the negative powers of the perturbation parameter appeared in the considered *** results illustrate that the computing cost of the proposed two-grid method is much less than that of the conventional Galerkin MFEM without loss of accuracy.

关键词： Time-dependent Bi-wave problem Two-grid mixed finite element method Uniform superclose and superconvergent estimates

Engineering high-performance dielectric chiral shells with enhanced chiral fields for sensitive chiral biosensor

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Rare Metals 2024年第3期43卷 1197-1206页

作者： Yi-Fan Wang Shan-Shan huang Zhen-Dong Dai shi-Lin Xian Xuan-Nan wu Fu-hua Gao Yi-Dong Hou College of Physics Sichuan UniversityChengdu610065China Graduate School of Sichuan University Sichuan UniversityChengdu610065China

Chiral metamaterials have been a topic of significant research interest in recent years due to their potential for various applications in nanophotonic devices and chiral ***,the intrinsic Ohmic loss in surface plasmonic resonance has limited their practical use,resulting in large light dissipation and weak chiroptical ***,we report on the development of high-performance dielectric chiral shells(DCS)through a two-step Si deposition process on a self-assembled microsphere *** form DCS sample completely oyercomes the cancelation effect originated from the disorder property of the micro-sphere monolayer in macroscale,and at a wavelength of approximately 710 nm,the measured optimal chiral signal(g-factor)and transmittance can reach up to 0.7 and 0.3,*** strong chiroptical effect comes from the asymmetric circular displacement currents(i.e.,magnetic modes)enabled by the specific shell *** chiral shell geometry,electromagnetic properties,sensor sensitivity of chiral molecules and figure of merit are systematically *** DCSs demonstrate highly sensitive detection of chiral biomolecules owing to their easily accessible geometry and enhanced uniform chiral field.

关键词： Dielectric chiral shells(DCS) Si deposition Magnetic resonance Highly sensitive sensor Chiral field

Left ventricular thrombosis caused cerebral embolism during venoarterial extracorporeal membrane oxygenation support: A case report

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World Journal of Clinical Cases 2024年第5期12卷 973-979页

作者： Yao-Bang Bai Feng Zhao Zhen-hua wu Guo-Ning shi Nan Jiang Intensive Care Unit Department of Cardiac SurgeryTianjin Chest HospitalTianjin 300222China Department of Cardiac Surgery Tianjin Chest HospitalTianjin 300222China

BACKGROUND Venoarterial(VA)extracorporeal membrane oxygenation(ECMO),an effective short-term circulatory support method for refractory cardiogenic shock,is widely ***,retrospective analyses have shown that VA-ECMO-assisted cases were associated with a relatively high mortality rate of approximately 60%.Embolization in important organs caused by complications of left ventricular thrombosis(LVT)during VA-ECMO is also an important *** the incidence of LVT during VA-ECMO is not high,the consequences of embolization are *** SUMMARY A 37-year-old female patient was admitted to hospital because of fever for 4 d and palpitations for 3 *** excluding the diagnosis of coronary heart disease,we established a diagnosis of“clinically explosive myocarditis”.The patient still had unstable hemodynamics after drug treatment supported by VA-ECMO,with heparin for *** day 4 of ECMO support,a left ventricular thro-mbus attached to the papillary muscle root of the mitral valve was found by transthoracic *** ventricular decompression was performed and ECMO was successfully removed,but the patient eventually died of multiple cerebral *** LVT with high mobility during VA-ECMO may cause embolism in important ***,a"wait and see"strategy should be avoided.

关键词： Venoarterial extracorporeal membrane oxygenation Left ventricular thrombosis Cerebral embolism Magnetic Resonance Imaging Therapy Case report

室温研磨固相反应法制备γ-Fe_2O_3纳米粉体及其气敏性能研究

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无机化学学报 2006年第3期22卷 483-487页

作者：景志红吴世华曲阜师范大学化学学院曲阜273165 南开大学化学学院天津300071

本文首次以硝酸铁Fe(NO3)3·9H2O、氢氧化钠NaOH和聚乙二醇(PEG-200)为反应物,采用室温研磨固相反应法合成了γ-Fe2O3纳米粉体,并用红外光谱(FTIR)、X射线粉末衍射(XRD)、透射电镜(TEM)和气敏元件测试系统对产物的结构、表观形貌及气敏... 详细信息

本文首次以硝酸铁Fe(NO3)3·9H2O、氢氧化钠NaOH和聚乙二醇(PEG-200)为反应物,采用室温研磨固相反应法合成了γ-Fe2O3纳米粉体,并用红外光谱(FTIR)、X射线粉末衍射(XRD)、透射电镜(TEM)和气敏元件测试系统对产物的结构、表观形貌及气敏性能进行表征。结果表明,FeOOH在300￣500℃热处理1h均为γ-Fe2O3晶相,粒径为4￣10nm;600℃热处理1h后转化为α-Fe2O3晶相。300℃焙烧后获得的γ-Fe2O3纳米粉体制成的气敏元件对乙醇有较高的灵敏度和较好的选择性。另外,以FeCl3为铁源时仅能得到纯α-Fe2O3纳米粉体,表明不同的铁源和PEG碳链的长短对产物的形成具有至关重要的影响。

关键词： γ-Fe2O3纳米粉体研磨固相反应法气敏性能聚乙二醇

Sequential enantioselective Ugi-4CR/post-Ugi transformation strategy:a precise construction of structurally diverse azaspiro polycyclic scaffolds

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Science China Chemistry 2024年第2期67卷 576-586页

作者： Xiao-Bao wu Jun-Xiu shi Yi-Ming Ou hua-Jie Jiang Yi-Jun Fang Qi-Ming Wang Quan Gao Jie Yu Department of Applied Chemistry Anhui Province Engineering Laboratory for Green Pesticide Development and ApplicationAnhui Province Key Laboratory of Crop Integrated Pest ManagementAnhui Agricultural UniversityHefei230036China

A privileged strategy has been developed for the precise construction of enantioenriched azaspiro polycyclic *** diverse azaspiro polycycles bearing multiple contiguous stereocenters are obtained with excellent results(up to 99:1 e.r.,>95:5 d.r.) via sequential enantioselective four-component Ugi reactions/post-Ugi transformations with substrates containing prerequisite functional groups in the presence of anionic stereogenic-at-cobalt(Ⅲ) complexes.

关键词： asymmetric catalysis post-Ugi transformation anionic stereogenic-at-cobalt(Ⅲ)complex azaspiro polycyclic scaffold one-pot synthesis

Metal-free two-dimensional phosphorene-based electrocatalyst with covalent P-N heterointerfacial reconstruction for electrolyte-lean lithium-sulfur batteries

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Carbon Energy 2024年第5期6卷 175-185页

作者： Jiangqi Zhou Chengyong Shu Jiawu Cui Chengxin Peng Yong Liu Weibo hua Laura Simonelli Yuping wu shi Xue Dou Wei Tang School of Chemical Engineering and Technology Xi'an Jiaotong UniversityXi'anChina School of Materials Science and Engineering University of Shanghai for Science and TechnologyShanghaiChina State Key Laboratory of Space Power-Sources Technology Shanghai Institute of Space Power-SourcesShanghaiChina CELLS-ALBA Synchrotron BarcelonaSpain School of Energy and Environment Southeast UniversityNanjingChina

The use of lithium-sulfur batteries under high sulfur loading and low electrolyte concentrations is severely restricted by the detrimental shuttling behavior of polysulfides and the sluggish kinetics in redox ***-dimensional(2D)few layered black phosphorus with fully exposed atoms and high sulfur affinity can be potential lithium-sulfur battery electrocatalysts,which,however,have limitations of restricted catalytic activity and poor electrochemical/chemical *** resolve these issues,we developed a multifunctional metal-free catalyst by covalently bonding few layered black phosphorus nanosheets with nitrogen-doped carbon-coated multiwalled carbon nanotubes(denoted c-FBP-NC).The experimental characterizations and theoretical calculations show that the formed polarized P-N covalent bonds in c-FBP-NC can efficiently regulate electron transfer from NC to FBP and significantly promote the capture and catalysis of lithium polysulfides,thus alleviating the shuttle ***,the robust 1D-2D interwoven structure with large surface area and high porosity allows strong physical confinement and fast mass ***,with c-FBP-NC as the sulfur host,the battery shows a high areal capacity of 7.69 mAh cm^(−2) under high sulfur loading of 8.74 mg cm^(−2) and a low electrolyte/sulfur ratio of 5.7μL mg^(−1).Moreover,the assembled pouch cell with sulfur loading of 4 mg cm^(−2) and an electrolyte/sulfur ratio of 3.5μL mg^(−1) shows good rate capability and outstanding *** work proposes an interfacial and electronic structure engineering strategy for fast and durable sulfur electrochemistry,demonstrating great potential in lithium-sulfur batteries.

关键词： black phosphorus electronic structure high sulfur loading interfacial covalent bonds lean electrolyte

Liquid-metal microgrid stretchable electronics based on bionic leaf veins with ultra-stretchability and high conductivity

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Rare Metals 2024年第6期43卷 2747-2757页

作者： Xi-Di Sun Jun-Yang An Yi-Qi Sun Xin Guo Jing wu Jiang-Bo hua Meng-Rui Su Yi shi Li-Jia Pan Collaborative Innovation Center of Advanced Microstructures School of Electronic Science and EngineeringNanjing UniversityNanjing 210093China

Stretchable electronics that monitor joint activity and treat diseases based on liquid metal could be used in the development of healthcare *** devices can be seamlessly integrated with human ***,most high-precision microstructures and complex patterns are difficult to fabricate due to the limitations of conventional fabrication solutions,resulting in suboptimal performance under practical ***,a liquid-metal stretchable system utilizing natural leaf veins was reported as microstructures,which was based on a biomimetic concept and utilized an all-solution process for the preparation of complex *** systems are ultra-high tensile(800%tensile strain),environmentally stable(20 days)and mechanically durable(300-cycle).The system can accurately recognize the wearer's finger bending level as well as simple gesture *** the same time,the system acts as a wearable heater,which can realize the fast heating behavior of heating up to 50℃in 3 min under the human body-safe voltage(1.5 V).The tensile stability is demonstrated by the heterogeneous integration of lasers(405 nm)with the system interconnects for a stretchable and wearable light source.

关键词： Stretchable electronics Liquid metal Stretchable conductor Vein Bionicist electronics

Linear Viscoelasticity of ABA-type Vitrimer Based on Dioxaborolane Metathesis

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Chinese Journal of Polymer Science 2024年第10期42卷 1495-1504页

作者： shi-Long wu huan-huan Yang Quan Chen State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Science University of Science and Technology of China

In this study, we synthesized a series of ABA-type vitrimers by crosslinking the short A moieties of precursors with a bifunctional crosslinker and evaporating the small molecular byproduct. The vitrimer samples thus prepared exhibit linear viscoelasticity dependent on the length of A moiety as well as the content of the crosslinks. When the average number of A monomers per end moiety m=1.1, the crosslinker can only extend the chain but not crosslink the chain. When m becomes 2.8 or higher, introducing a crosslinker first leads to the gelation, whereas excess in crosslinker molecules leads opening of the crosslinking sites and accordingly reentry into the sol regime. Surprisingly, a further increase in the length of the A moieties increases the relaxation time much weaker than the exponential increase seen for the physically crosslinked ABAtype ionomers. We attribute this difference to the distinct relaxation mechanisms:the relaxation of the vitrimer samples is based on relatively independent exchange reactions, which contrasts with the ABA-type ionomers that relax through the collective hopping of connected ionic groups from one ion aggregate to another.

关键词： ABA-type vitrimer Kinetics and thermodynamics Linear viscoelasticity Polymer rheology Relaxation mechanism

Loyal wingman task execution for future aerial combat:A hierarchical prior-based reinforcement learning approach

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Chinese Journal of Aeronautics 2024年第5期37卷 462-481页

作者： Jiandong ZHANG Dinghan WANG Qiming YANG Zhuoyong shi Longmeng JI Guoqing shi Yong wu School of Electronics and Information Northwestern Polytechnical UniversityXi’an 710129China

In modern Beyond-Visual-Range(BVR)aerial combat,unmanned loyal wingmen are pivotal,yet their autonomous capabilities are *** study introduces an advanced control algorithm based on hierarchical reinforcement learning to enhance these capabilities for critical missions like target search,positioning,and relay *** on a dual-layer model,the algorithm’s lower layer manages basic aircraft maneuvers for optimal flight,while the upper layer processes battlefield dynamics,issuing precise navigational *** approach enables accurate navigation and effective reconnaissance for lead ***,our Hierarchical Prior-augmented Proximal Policy Optimization(HPE-PPO)algorithm employs a prior-based training,prior-free execution method,accelerating target positioning training and ensuring robust target *** paper also improves missile relay guidance and promotes the effective *** integrating this system with a human-piloted lead aircraft,this paper proposes a potent solution for cooperative aerial *** experiments demonstrate enhanced survivability and efficiency of loyal wingmen,marking a significant contribution to Unmanned Aerial Vehicles(UAV)formation control *** advancement is poised to drive substantial interest and progress in the related technological fields.

关键词： Beyond-visual-range Loyal wingmen Hierarchical prior-augmented proximal policy optimization Unmanned aerial vehicles Warfare

聚苯胺/二氧化锡杂化材料的制备、表征及气敏性测试

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无机化学学报 2011年第1期27卷 47-52页

作者：耿丽娜吴世华河北师范大学化学学院石家庄050016 南开大学化学学院天津300071

文章采用水热法、苯胺原位聚合法制备了聚苯胺/二氧化锡(PAn/SnO2)杂化材料,用FTIR、XRD、TEM、XPS等多种手段对产物进行表征,并在较低操作温度下(室温、60℃和90℃)测试其对乙醇、氢气、一氧化碳和氨气的气敏性能。结果表明,苯胺单体在... 详细信息

文章采用水热法、苯胺原位聚合法制备了聚苯胺/二氧化锡(PAn/SnO2)杂化材料,用FTIR、XRD、TEM、XPS等多种手段对产物进行表征,并在较低操作温度下(室温、60℃和90℃)测试其对乙醇、氢气、一氧化碳和氨气的气敏性能。结果表明,苯胺单体在SnO2的表面发生原位聚合,得到核壳型PAn/SnO2杂化材料。气敏性实验发现,当测试温度升高到90℃时,PAn/SnO2杂化材料对乙醇气体表现出较好的选择性,并且响应、恢复时间短,可逆性好,适于在较宽浓度范围对乙醇气体进行检测。

关键词：聚苯胺/二氧化锡杂化材料气敏性能透射电镜 X-射线光电子能谱