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Sequential over-barrier ionization of multi-electron atoms in the tens-to-hundreds keV/u energy range 被引量:1
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作者 邹贤容 刘兰雕 +3 位作者 姬明超 冯冬 陈熙萌 邵剑雄 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第3期191-194,共4页
Our previous work on the classical over-barrier ionization model for helium double ionization is extended to the complex multi-electron system of Ne. The total and q-fold ionization cross sections are calculated at en... Our previous work on the classical over-barrier ionization model for helium double ionization is extended to the complex multi-electron system of Ne. The total and q-fold ionization cross sections are calculated at energies ranging from a few tens to several hundred keV/u. The calculation results are in good agreement with the experimental data, and the energy dependence of the cross sections suggests that the multi-ionization of a strong perturbated complex atom is probably the sequential over-barrier ionization process. 展开更多
关键词 multi-electron system multi-ionization over-barrier ionization
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Designing electrode materials for aluminum-ion batteries towards fast diffusion and multi-electron reaction 被引量:1
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作者 Lumin Zheng Haoyi Yang +1 位作者 Ying Bai Chuan Wu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第9期229-232,共4页
Since the electrochemical energy storage was invented, mobile has brought us a new world without wires for more electronic devices [1–4]. Aluminum ion batteries(AIBs) were born with the requirements of electrochemica... Since the electrochemical energy storage was invented, mobile has brought us a new world without wires for more electronic devices [1–4]. Aluminum ion batteries(AIBs) were born with the requirements of electrochemical energy storage towards high capacity, safe and low cost. 展开更多
关键词 Aluminum-ion batteries Theory research Electrode materials DYNAMICS multi-electron reaction
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Multi-Electron Effects in Attosecond Transient Absorption of CO Molecules 被引量:1
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作者 Bin Zhang Jian Zhao Zeng-Xiu Zhao 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第4期20-24,共5页
Using the fully propagated time-dependent Hartree–Fock method, we identify that both the dynamic core polarization and multiorbital contributions are important in the attosecond transient absorption of CO molecules.T... Using the fully propagated time-dependent Hartree–Fock method, we identify that both the dynamic core polarization and multiorbital contributions are important in the attosecond transient absorption of CO molecules.The dynamics of core electrons effectively modifies the behaviors of electrons in the highest occupied molecular orbital, resulting in the modulation of intensity and position of the absorption peaks. Depending on the alignment angles, different inner orbitals are identified to contribute, and even dominate the total absorption spectra. As a result, multi-electron fingerprints are encoded in the absorption spectra, which shed light on future applications of attosecond transient absorption in complex systems. 展开更多
关键词 multi-electron Effects in Attosecond Transient Absorption of CO Molecules SAO AS CO
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Multi-electron reaction concept for the universal battery design 被引量:1
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作者 Feng Wu Haoyi Yang +1 位作者 Ying Bai Chuan Wu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2020年第12期416-417,共2页
Electrochemical batteries define the contraption stores electricity in the direct form of chemical energy with high efficiency. If the energy conversion process can be reversed, namely the input and output of electric... Electrochemical batteries define the contraption stores electricity in the direct form of chemical energy with high efficiency. If the energy conversion process can be reversed, namely the input and output of electricity both being permitted, the batteries are termed rechargeable batteries or also secondary batteries accordingly [1]. These decades have witnessed the rapid development of batteries because of the demands for transportation of information and mass in the mobile area, and stationary storage for the implementation of renewable energy technologies. 展开更多
关键词 multi-electron reaction Electrode material Redox chemistry
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NOVEL SYNTHESIS OF POLYARYLENESULFONIUM CATIONS THROUGH A MULTI-ELECTRON TRANSFER PROCESS
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作者 TSUCHIDA Eishun MIYATAKE Kenji 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1998年第2期106-116,共11页
The oxidative polymerization of aryl sulfoxides provides a novel polysulfo-nium compound, poly(methylsulfonio-1,4-phenylenethio-1,4-phenylene cation) in quantita-tive yield. The polymerization proceeds efficiently in ... The oxidative polymerization of aryl sulfoxides provides a novel polysulfo-nium compound, poly(methylsulfonio-1,4-phenylenethio-1,4-phenylene cation) in quantita-tive yield. The polymerization proceeds efficiently in an acidic solution under atmosphericconditions. Oxygen, chemical and electrochemical oxidations are available. Vanadyl acety-lacetonate and cerium ammonium nitrate act as an effective catalyst for the oxygen ox-idative polymerization. The polymerization mechanism involves multielectron oxidation ofthe sulfides followed by successive electrophilic substitution. The resulting polyarylenesul-fonium cations are useful as a soluble precursor for the synthesis of high molecular weight(M_w>10~5) poly(thio arylne)s. 展开更多
关键词 Oxidative polymerization multi-electron transfer Sulfonium cation Poly(thio phenylene)
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Stable multi-electron reaction stimulated by W doping VS_(4)for enhancing magnesium storage performance
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作者 Yuxin Tian Jiankang Chen +7 位作者 Guofeng Wang Bing Sun Alan Meng Lei Wang Guicun Li Jianfeng Huang Shiqi Ding Zhenjiang Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期89-98,I0004,共11页
Rechargeable magnesium batteries(RMBs)hold promise for offering higher volumetric energy density and safety features,attracting increasing research interest as the next post lithium-ion batteries.Developing high perfo... Rechargeable magnesium batteries(RMBs)hold promise for offering higher volumetric energy density and safety features,attracting increasing research interest as the next post lithium-ion batteries.Developing high performance cathode material by inducing multi-electron reaction process as well as maintaining structural stability is the key to the development and application of RMBs.Herein,multielectron reaction occurred in VS_(4)by simple W doping strategy.W doping induces valence of partial V as V^(2+)and V^(3+)in VS_(4)structure,and then stimulates electrochemical reaction involving multi-electrons in 0.5%W-V-S.The flower-like microsphere morphology as well as rich S vacancies is also modulated by W doping to neutralize structure change in such multi-electron reaction process.The fabricated 0.5%W-V-S delivers higher specific capacity(149.3 m A h g^(-1)at 50 m A g^(-1),which is 1.6 times higher than that of VS_(4)),superior rate capability(76 mA h g^(-1)at 1000 mA g^(-1)),and stable cycling performance(1500cycles with capacity retention ratio of 93.8%).Besides that,pesudocapaticance-like contribution analysis as well as galvanostatic intermittent titration technique(GITT)further confirms the enhanced Mg^(2+)storage kinetics during such multi-electron involved electrochemical reaction process.Such discovery provides new insights into the designing of multi-electron reaction process in cathode as well as neutralizing structural change during such reaction for realizing superior electrochemical performance in energy storage devices. 展开更多
关键词 multi-electron reaction W doping Stable structure CATHODE Rechargeable magnesium batteries
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Influence of core property on multi-electron process in slow collisions of isocharged sequence ions with neon
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作者 卢荣春 于得洋 +2 位作者 邵曹杰 阮芳芳 蔡晓红 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第11期475-488,共14页
Influence of core property on multi-electron process in the collisions of q = 6-9 and 11 isocharged sequence ions with Ne is investigated in the keV/u region. The cross-section ratios of double-, triple-, quadruple- a... Influence of core property on multi-electron process in the collisions of q = 6-9 and 11 isocharged sequence ions with Ne is investigated in the keV/u region. The cross-section ratios of double-, triple-, quadruple- and total multielectron processes to the single electron capture process as well as the partial ratios of different reaction channels to the relevant multi-electron process are measured by using position-sensitive and time-of-flight techniques. The experimental data are compared with the theoretical predictions including the extended classical over-barrier model, the molecular Columbic barrier model and the semi-empirical scaling law. Results show a core effect on multi-electron process of isocharge ions colliding with Neon, which is consistent with the results of Helium we obtained previously. 展开更多
关键词 isocharged sequence ions multi-electron process classical over-barrier model
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Multi-electron reaction and fast Al ion diffusion of δ-MnO_(2) cathode materials in rechargeable aluminum batteries via first-principle calculations
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作者 Lumin Zheng Ying Bai Chuan Wu 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第4期248-254,共7页
Rechargeable aluminum batteries with multi-electron reaction have a high theoretical capacity for next generation of energy storage devices. However, the diffusion mechanism and intrinsic property of Al insertion into... Rechargeable aluminum batteries with multi-electron reaction have a high theoretical capacity for next generation of energy storage devices. However, the diffusion mechanism and intrinsic property of Al insertion into MnO_(2) are not clear. Hence, based on the first-principles calculations, key influencing factors of slow Al-ions diffusion are narrow pathways, unstable Al-O bonds and Mn^(3+) type polaron have been identified by investigating four types of δ-MnO_(2)(O3, O'3, P2 and T1). Although Al insert into δ-MnO_(2) leads to a decrease in the spacing of the Mn-Mn layer, P2 type MnO_(2) keeps the long(spacious pathways)and stable(2.007–2.030 A) Al-O bonds resulting in the lower energy barrier of Al diffusion of 0.56 e V. By eliminated the influence of Mn^(3+)(low concentration of Al insertion), the energy barrier of Al migration achieves 0.19 e V in P2 type, confirming the obviously effect of Mn^(3+) polaron. On the contrary, although the T1 type MnO_(2) has the sluggish of Al-ions diffusion, the larger interlayer spacing of Mn-Mn layer,causing by H_(2)O could assist Al-ions diffusion. Furthermore, it is worth to notice that the multilayer δ-MnO_(2) achieves multi-electron reaction of 3|e|. Considering the requirement of high energy density, the average voltage of P2(1.76 V) is not an obstacle for application as cathode in RABs. These discover suggest that layered MnO_(2) should keep more P2-type structure in the synthesis of materials and increase the interlayer spacing of Mn-Mn layer for providing technical support of RABs in large-scale energy storage. 展开更多
关键词 Rechargeable aluminum batteries δ-MnO_(2) First-principles calculations multi-electron reaction Diffusion mechanism
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A New Differential Formula About Product of Polynomials and Its Application in Multi-electron State Physics
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作者 FAN Hong-Yi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第3X期419-422,共4页
We derive a new differential formula about a kind of product of polynomials and then apply it to analyze some properties of multi-electron state "related to Laughlin wave function". The entangled state representatio... We derive a new differential formula about a kind of product of polynomials and then apply it to analyze some properties of multi-electron state "related to Laughlin wave function". The entangled state representation for describing electrons in uniform magnetic field is used. 展开更多
关键词 new differential formula product of polynomials multi-electron state
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Defect engineering for achieving multi-electrons storage in VS_(4) to enhance magnesium storage performance
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作者 Jiankang Chen Guofeng Wang +7 位作者 Bing Sun Yu Zhang Maoyuan Li Lei Wang Guicun Li Alan Meng Shiqi Ding Zhenjiang Li 《Nano Research》 2025年第6期346-353,共8页
Defect engineering acts as an efficiency method to modulate the microstructure and electronic structure of cathode for rechargeable magnesium batteries(RMBs).Owing to rich sulfur(S)vacancies tunes the electronic struc... Defect engineering acts as an efficiency method to modulate the microstructure and electronic structure of cathode for rechargeable magnesium batteries(RMBs).Owing to rich sulfur(S)vacancies tunes the electronic structure of VS4 with rich S vacancies(V_(S)-VS_(4)),the lower oxidation state of V^(3+)is induced for achieving the V^(3+)/V^(4+)and V^(4+)/V^(5+)multi-electrons reaction for Mg^(2+)storage.Amorphous structure is also constructed in VS-VS4 by chemical vapor deposition(CVD)method under the high temperature for providing fast magnesium ions(Mg^(2+))diffusion channels and expanding inner stress release space to balance the structural stability of multi-electrons reaction process.The simple defect engineering realizes the stable multi-electrons reaction in V_(S)-VS_(4) for enhancing its Mg^(2+)storage performance with higher specific capacity(158.6 mAh·g^(-1) at 50 mA·g^(-1)),stable cycling performance(capacity retention ratio of 72.7% after 3600 cycles)and the superior rate capability.This work provides electrode designing guidance for achieving stable multi-electrons to fully utilize the bivalent property of multivalence metal batteries. 展开更多
关键词 defect engineering multi-electrons reaction VS_(4) CATHODE rechargeable magnesium batteries(RMBs)
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Multi-electron Reaction Materials for High-Energy-Density Secondary Batteries:Current Status and Prospective 被引量:3
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作者 Xinran Wang Guoqiang Tan +2 位作者 Ying Bai Feng Wu Chuan Wu 《Electrochemical Energy Reviews》 SCIE EI 2021年第1期35-66,共32页
To address increasing energy supply challenges and allow for the effective utilization of renewable energy sources,transformational and reliable battery chemistry are critically needed to obtain higher energy densitie... To address increasing energy supply challenges and allow for the effective utilization of renewable energy sources,transformational and reliable battery chemistry are critically needed to obtain higher energy densities.Here,significant progress has been made in the past few decades in energetic battery systems based on the concept of multi-electron reactions to overcome existing barriers in conventional battery research and application.As a result,a systematic understanding of multi-electron chemistry is essential for the design of novel multi-electron reaction materials and the enhancement of corresponding battery performances.Based on this,this review will briefly present the advancements of multi-electron reaction materials from their evolutionary discovery from lightweight elements to the more recent multi-ion effect.In addition,this review will discuss representative multi-electron reaction chemistry and materials,including ferrates,metal borides,metal oxides,metal fluorides,lithium transition metal oxides,silicon,sulfur and oxygen.Furthermore,insertion-type,alloy-type and conversion-type multi-electron chemistry involving monovalent Li^(+) and Na^(+) cations,polyvalent Mg^(2+) and Al^(3+) cations beyond those of alkali metals as well as activated S^(2−) and O^(2−) anions are introduced in the enrichment and development of multi-electron reactions for electrochemical energy storage applications.Finally,this review will present the ongoing challenges and underpinning mechanisms limiting the performance of multi-electron reaction materials and corresponding battery systems. 展开更多
关键词 multi-electron reaction Multi-ion effect Lightweight element Secondary battery Energy density
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Unlocking the multi-electron transfer reaction in NASICON-type cathode materials 被引量:1
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作者 Yuan Liu Xiaohui Rong +4 位作者 Fei Xie Yaxiang Lu Junmei Zhao Liquan Chen Yong-Sheng Hu 《Materials Futures》 2023年第2期109-122,共14页
The growing concern about scarcity and large-scale applications of lithium resources has attracted efforts to realize cost-effective phosphate-based cathode materials for next-generation Na-ion batteries(NIBs).In prev... The growing concern about scarcity and large-scale applications of lithium resources has attracted efforts to realize cost-effective phosphate-based cathode materials for next-generation Na-ion batteries(NIBs).In previous work,a series of materials(such as Na_(4)Fe_(3)(PO_(4))_(2)(P_(2)O_(7)),Na_(3)VCr(PO_(4))_(3),Na_(4)VMn(PO_(4))3,Na_(3)MnTi(PO_(4))_(3),Na_(3)MnZr(PO_(4))3,etc)with∼120 mAh g^(-1) specific capacity and high operating potential has been proposed.However,the mass ratio of the total transition metal in the above compounds is only∼22 wt%,which means that one-electron transfer for each transition metal shows a limited capacity(the mass ratio of Fe is 35.4 wt%in LiFePO_(4)).Therefore,a multi-electron transfer reaction is necessary to catch up to or go beyond the electrochemical performance of LiFePO_(4).This review summarizes the reported NASICON-type and other phosphate-based cathode materials.On the basis of the aforementioned experimental results,we pinpoint the multi-electron behavior of transition metals and shed light on designing rules for developing high-capacity cathodes in NIBs. 展开更多
关键词 NASICON Na-ion batteries cathode materials multi-electron transfer reactions
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融合多源感知数据的电子围栏智慧作业区安全态势智能预测
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作者 王玉龙 王龙磊 《计算机应用文摘》 2026年第1期82-84,共3页
在电子围栏智慧作业区安全态势分析中,当前方法普遍依赖单一感知数据源,未能充分利用多源数据间的冗余与互补特征,导致预测误差较大。为此,文章提出一种融合多源感知数据的智慧作业区安全态势预测方法。首先采用自适应离散化对多源感知... 在电子围栏智慧作业区安全态势分析中,当前方法普遍依赖单一感知数据源,未能充分利用多源数据间的冗余与互补特征,导致预测误差较大。为此,文章提出一种融合多源感知数据的智慧作业区安全态势预测方法。首先采用自适应离散化对多源感知数据进行统一量化,并基于粒子群优化算法计算各数据源的融合权重;其次利用卷积神经网络提取安全态势特征,通过Sigmoid激活函数映射得到安全指数;最终结合大数据分析计算安全态势预测值,并依据阈值划分安全等级。实验结果表明,该方法能有效提升预测精度,绝对误差始终保持在0.1以内。 展开更多
关键词 多源感知数据 电子围栏 智慧作业区 安全态势 预测方法
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基于STM32的多传感智能小车控制系统设计
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作者 郭峻宇 白英凯 +1 位作者 方孜儇 吴倩仪 《汽车电器》 2026年第1期54-56,共3页
为满足智能移动机器人在简单环境下的导航需求,本文设计基于STM32F103C8微控制器的智能移动平台控制系统。该系统集成超声波传感器、四路红外传感器及光敏电阻等感知设备,采用TB6612FNG驱动芯片控制四轮直流减速电机,通过蓝牙实现手机... 为满足智能移动机器人在简单环境下的导航需求,本文设计基于STM32F103C8微控制器的智能移动平台控制系统。该系统集成超声波传感器、四路红外传感器及光敏电阻等感知设备,采用TB6612FNG驱动芯片控制四轮直流减速电机,通过蓝牙实现手机远程控制,实现自主避障、红外循迹、光源追踪、蓝牙遥控等功能。测试结果显示,避障成功率达90%,循迹精度控制在5 cm以内,追光响应延迟小于0.5 s,蓝牙控制延迟小于0.3 s。该系统为汽车辅助驾驶系统的环境感知模块开发提供低成本验证平台。 展开更多
关键词 STM32微控制器 多传感器融合 智能控制 嵌入式系统 汽车电子
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多束电子源设计与实验
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作者 赵伟霞 白凌超 +3 位作者 张利新 刘俊标 殷伯华 韩立 《光学精密工程》 北大核心 2025年第5期741-750,共10页
为了提高扫描电子显微镜等单电子束设备的通量,开发了基于肖特基阴极的多束电子源系统,研究了准直透镜、分束板及微阵列静电透镜的设计方法与制备工艺。根据肖特基阴极发射特性进行了静电准直透镜的设计,仿真计算了准直束的电子光学性... 为了提高扫描电子显微镜等单电子束设备的通量,开发了基于肖特基阴极的多束电子源系统,研究了准直透镜、分束板及微阵列静电透镜的设计方法与制备工艺。根据肖特基阴极发射特性进行了静电准直透镜的设计,仿真计算了准直束的电子光学性能。基于MEMS加工工艺实现了3×3和10×10多孔阵列分束板的制备,开发了多孔多层器件装配系统并实现了微阵列静电透镜的高精度装配;搭建了多束电子源测试平台并进行了多束电子源的准直、分束与聚焦性能验证。结果表明:多束电子源的准直束范围为600μm,准直范围内的束流密度为4.11 A/m^(2)、均匀度为6.06%;实现了3×3分束且大小可调,聚焦后的子束束斑直径均值为5.32μm,束斑直径均匀度为5.91%,束流强度均匀度为4.36%,间距均匀度为3.06%,满足多电子束设备的设计要求。 展开更多
关键词 电子光学 多束电子源 肖特基发射 准直透镜 微阵列单电位透镜
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Robust sodium storage enabled medium entropy Na_(3.5)V_(0.5)Mn_(0.5)Fe_(0.5)Ti_(0.5)(PO_(4))_(3) NASICON with multielectron reaction for sodium-ion battery
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作者 Muhammad Tayyab Ahsan Zeeshan Ali +2 位作者 Jing-Jing Wang Wan-Ting Zhao Yang-Long Hou 《Rare Metals》 2025年第4期2328-2339,共12页
Sodium superionic conductors(NASICONs)have attracted enormous attention owing to their excellent ionic diffusion and structural stability.However,the high cost of vanadium,limited capacity due to fewer redox reactions... Sodium superionic conductors(NASICONs)have attracted enormous attention owing to their excellent ionic diffusion and structural stability.However,the high cost of vanadium,limited capacity due to fewer redox reactions,and low electronic conductivity restrict their practical application.Herein,we designed Na_(3.5)V_(0.5)Mn_(0.5)Fe_(0.5)Ti_(0.5)(PO_(4))3 (NVMFTP)medium entropy NASICON with multi-electron reactions as a fast sodium storage cathode for sodium-ion batteries(SIBs).The incorporation of Fe,Mn and Ti not only reduces the cost but also activates multi-redox reactions of V^(2+)/V^(3+),Ti^(3+)/Ti^(4+),Fe^(2+)/Fe^(3+),V^(3+)/V^(4+),Mn^(2+)/Mn^(3+),V^(4+)/V^(5+).Owing to distinctive structural design with medium entropy,the NVMFTP delivered 168 mAh·g^(−1) at 0.5C with a remarkable rate capability of 93.51 mAh·g^(−1) at 60C and steady long-term cycling performance till 5000 cycles.More importantly,NVMFTP takes only 11 min to achieve 80%SOC at 5C.The in-situ and ex-situ X-ray diffraction(XRD)further demonstrate reversible multi-electron reaction mechanisms of slow charging and fast charging.NVMFTP/HC full cell shows 110 mAh·g^(−1) capacity and 208 Wh·kg^(−1) energy density.This study will provide comprehensive insight into developing low-cost,cutting-edge materials for SIBs. 展开更多
关键词 Sodium-ion batteries Medium entropy Cathode materials multi-electron reactions NASICON materials
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人体多生理参数采集系统实践教学项目设计
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作者 李华 朱健铭 +2 位作者 李宏周 肖文香 梁永波 《实验室研究与探索》 北大核心 2025年第5期190-195,228,共7页
设计了一种将模拟放大电路、数字电路、单片机控制、软件编程、人体解剖生理等多学科融合、跨度从大一到大四的综合性实践教学项目。通过理实结合,引导学生逐步完成硬件设计和软件编程,最终实现脉搏、血氧、心电、血压等人体多种生理参... 设计了一种将模拟放大电路、数字电路、单片机控制、软件编程、人体解剖生理等多学科融合、跨度从大一到大四的综合性实践教学项目。通过理实结合,引导学生逐步完成硬件设计和软件编程,最终实现脉搏、血氧、心电、血压等人体多种生理参数的采集,并将数据传输至QT上位机。在实践教学过程中,学生不仅将深入学习医学信号检测传感器的工作原理、信号采集与处理技术,还将掌握QT框架下的复杂用户界面和交互式应用程序的设计与实现,并具备单片机的编程与应用技能,从而有效提高生物医学工程专业学生运用电子信息技术进行医学检测系统设计的能力。经过5轮教学实践,该实验教学项目取得了较好的效果。 展开更多
关键词 医学电子仪器 多学科融合 实践教学 生理信号采集 医学检测
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圆二色多通道光谱分析樟脑磺酸铵盐的光学活性物质
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作者 王毅 单宇 赵亮 《分析试验室》 北大核心 2025年第10期1464-1468,共5页
本研究采用圆二色(CD)光谱仪加载旋光扩散、漫透射圆二色、漫反射圆二色和线二色性多通道技术,对(1s)-(+)-10-樟脑磺酸铵盐进行电子圆二色(ECD)分析。结果表明,上述多通道技术具有各自的优势和局限性。联合使用多通道技术消除了浓度引... 本研究采用圆二色(CD)光谱仪加载旋光扩散、漫透射圆二色、漫反射圆二色和线二色性多通道技术,对(1s)-(+)-10-樟脑磺酸铵盐进行电子圆二色(ECD)分析。结果表明,上述多通道技术具有各自的优势和局限性。联合使用多通道技术消除了浓度引起的吸收扁平、溶剂散射和折射等产生的光谱干扰,得到(1s)-(+)-10-樟脑磺酸铵盐的光学活性光谱数据和真实的ECD光谱,为准确分析手性光学活性物质的立体结构、绝对构型和优势构象提供了新的方法。 展开更多
关键词 电子圆二色 多通道技术 手性光学活性物质
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用于分布式光伏制氢的高效紧凑多端口电力电子变换器
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作者 李驰 叶之菁 +4 位作者 舒文彬 翁幸 王继慷 郑泽东 刘敏 《电网技术》 北大核心 2025年第8期3278-3287,I0077,共11页
分布式光伏制氢不仅是一种有效的新能源消纳手段,还可以满足用户的多样化用能需求。多端口电力电子变换器支持多种能源形式端口互联,有助于推进分布式光伏制氢系统紧凑化。但是,由于光伏发电和电解制氢两个系统的端口电特性迥异,要求多... 分布式光伏制氢不仅是一种有效的新能源消纳手段,还可以满足用户的多样化用能需求。多端口电力电子变换器支持多种能源形式端口互联,有助于推进分布式光伏制氢系统紧凑化。但是,由于光伏发电和电解制氢两个系统的端口电特性迥异,要求多端口电力电子变换器能够适应各端口工作点的宽变化范围和快速波动,并在紧凑空间内安全稳定运行。当前有关多端口电力电子变换器的研究大多停留在实验室阶段,少量的工程样机不仅在效率和功率密度上表现欠佳,并且未就其在分布式光伏制氢应用中存在的一系列问题提出针对性解决策略。为此,该文提出了一种三端口CLLC谐振变换器拓扑以及纯内移相调制和功率解耦控制策略。该三端口变换器不仅实现了高效、高功率密度电能变换,而且可宽范围、快速地跟随光伏出力、调节制氢负载。最后,采用SiC MOSFET功率模块搭建了100kW变换器样机单元验证了以上性能。 展开更多
关键词 光伏制氢 高效 高功率密度 多端口电力电子变换器 隔离DC/DC变换器
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基于电子病历多模态数据的作物病害多元场景处方推荐方法研究
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作者 张领先 丁俊琦 +2 位作者 陈菲菲 李宜滨 张一丁 《农业机械学报》 北大核心 2025年第1期25-36,46,共13页
针对作物品种及病害种类繁杂、样本数据严重不平衡、处方类别多样及数据多模态等特点和难点,本文基于电子病历多模态数据整合,开展面向多样化、可拓展和多模态3种应用场景需求的作物病害处方推荐方法研究。针对常见病害多样化处方推荐... 针对作物品种及病害种类繁杂、样本数据严重不平衡、处方类别多样及数据多模态等特点和难点,本文基于电子病历多模态数据整合,开展面向多样化、可拓展和多模态3种应用场景需求的作物病害处方推荐方法研究。针对常见病害多样化处方推荐应用场景,基于CdsBERT-RCNN和诊断推理构建了作物病害多样化处方推荐模型,提升了面向32种常见病害的诊断准确度及处方推荐的多样化水平;针对未训练少见病害和新添处方应用场景,基于MC-SEM和语义检索构建了作物病害可拓展处方推荐模型,提升了语义匹配准确性和案例库检索速度,实现对未训练病害的处方推荐功能;针对多种模态信息采集和输入应用场景,基于BATNet多层特征融合构建了多模态作物病害处方推荐模型,提升了多模态数据输入的处方推荐性能。实验结果表明,CdsBERT-RCNN模型对32种常见病害的诊断准确率达到85.65%,F1值达到85.63%;不同完整性输入测试中,仅输入症状信息即可达到81.19%的准确率,而添加环境信息和作物信息分别使准确率进一步提高1.65、3.61个百分点;MC-SEM模型对电子病历语义匹配任务达到皮尔森相关系数86.34%和斯皮尔曼相关系数77.67%;封闭集和开放集上处方推荐准确率分别达到88.20%和82.04%,验证了模型对未训练病害的推荐能力;BATNet对于多模态输入处方推荐任务的准确率和F1值达到98.88%和98.83%;应用场景分析和测试验证了模型在不完整模态(纯文本或纯图像)和不完整信息输入(作物、环境、症状)情况下泛化能力。该研究为数字化赋能作物病害防治决策提供了新的思路。 展开更多
关键词 作物病害处方推荐 自然语言处理 语义检索 多模态融合 电子病历
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