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Unital辛代数的分解(英文)
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作者 白喜梅 刘文丽 《河北大学学报(自然科学版)》 CAS 2002年第3期291-293,共3页
考查了辛代数的分解 ,在此过程中充分运用了辛代数、李三系、李代数的关系 ,建立了三者之间的根基关系 ,并由此证明了unital辛代数的分解 .
关键词 unital辛代数 分解 根基 可解理想 李三系 李代数
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Non-Markovianity Measure Based on Brukner–Zeilinger Invariant Information for Unital Quantum Dynamical Maps
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作者 贺志 朱烈强 李莉 《Communications in Theoretical Physics》 SCIE CAS CSCD 2017年第3期255-260,共6页
A non-Markovianity measure based on Brukner–Zeilinger invariant information to characterize nonMarkovian effect of open systems undergoing unital dynamical maps is proposed. The method takes advantage of non-increasi... A non-Markovianity measure based on Brukner–Zeilinger invariant information to characterize nonMarkovian effect of open systems undergoing unital dynamical maps is proposed. The method takes advantage of non-increasing property of the Brukner–Zeilinger invariant information under completely positive and trace-preserving unital maps. The simplicity of computing the Brukner–Zeilinger invariant information is the advantage of the proposed measure because of mainly depending on the purity of quantum state. The measure effectively captures the characteristics of non-Markovianity of unital dynamical maps. As some concrete application, we consider two typical non-Markovian noise channels, i.e., the phase damping channel and the random unitary channel to show the sensitivity of the proposed measure. By investigation, we find that the conditions of detecting the non-Markovianity for the phase damping channel are consistent with the results of existing measures for non-Markovianity, i.e., information flow, divisibility and quantum mutual information. However, for the random unitary channel non-Markovian conditions are same to that of the information flow, but is different from that of the divisibility and quantum mutual information. 展开更多
关键词 non-Markovianity measure Brukner-Zeilinger invariant information unital maps
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Hermitian unital中的两个无限2-设计族
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作者 李荣荣 詹小秦 《湖北大学学报(自然科学版)》 CAS 2022年第4期496-500,共5页
本研究证明Hermitian unital中以3维特殊射影酉群PSU(3,q)作为旗传递自同构群的两个无限2-设计族的存在性,为旗传递2-设计的分类提供新的分类方法.
关键词 2-设计 Hermitian unital 自同构群 旗传递 PSU(3 q)
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Property T and strong property T for unital*-homomorphisms
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作者 Qing MENG 《Frontiers of Mathematics in China》 SCIE CSCD 2020年第2期385-398,共14页
We introduce and study property T and strong property T for unital*-homomorphisms between two unital C^*-algebras.We also consider the relations between property T and invariant subspaces for some canonical unital^-re... We introduce and study property T and strong property T for unital*-homomorphisms between two unital C^*-algebras.We also consider the relations between property T and invariant subspaces for some canonical unital^-representations.As a corollary,we show that when G is a discrete group,G is finite if and only if G is amenable and the inclusion map i:Cr^*(G)→B(l^2(G))has property T.We also give some new equivalent forms of property T for countable discrete groups and strong property T for unital C^*-algebras. 展开更多
关键词 unital*-homomorphism unital C^*-algebra *-bimodule property T strong property T
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The Ext-Group of Unitary Equivalence Classes of Unital Extensions
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作者 Yi Feng XUE 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2011年第12期2329-2342,共14页
Let A be a unital separable nuclear C*-algebra which belongs to the bootstrap category N and B be a separable stable C*-algebra. In this paper, we consider the group Ext,(A, B) consisting of the unitary equivalenc... Let A be a unital separable nuclear C*-algebra which belongs to the bootstrap category N and B be a separable stable C*-algebra. In this paper, we consider the group Ext,(A, B) consisting of the unitary equivalence classes of unital extensions T: A→ Q(B). The relation between Ext,(A, B) and Ext(A, B) is established. Using this relation, we show the half-exactness of Ext,(-, B) and the (UCT) for Ext,(A, B). Furthermore, under certain conditions, we obtain the half-exactness and Bott periodicity of Extu (A, .). 展开更多
关键词 unital extension multiplier algebra Ext-group quasi-unital -homomorphism
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Approximately unital operator systems
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作者 HUANG XuJian 《Science China Mathematics》 SCIE 2011年第6期1243-1257,共15页
The main theme of this paper is to consider a notion of 'approximately unital operator systems' including both C*-algebras and unital operator systems.The goals are to prove a version of the Choi-Effros theore... The main theme of this paper is to consider a notion of 'approximately unital operator systems' including both C*-algebras and unital operator systems.The goals are to prove a version of the Choi-Effros theorem for these systems,to introduce a functorial process for forming an approximately unital operator systems from a given matrix ordered vector space with a proper approximate order unit,to study second duals of these objects and to prove that a C*-algebra can be characterized as an approximately unital operator system that is also an approximately unital matrix ordered *-algebra. 展开更多
关键词 approximately unital operator systems approximately unital matrix order *-algebras
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Universal C*-algebras Defined by Completely Bounded Unital Homomorphisms
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作者 Wen Hua QIAN Don HADWIN 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2015年第12期1825-1844,共20页
Suppose A is a unital C*-algebra and r 1.In this paper,we define a unital C*-algebra C(cb)*(A,r) and a completely bounded unital homomorphism αr:A → C(cb)*(A,r)with the property that C(cb)*(A,r)=C... Suppose A is a unital C*-algebra and r 1.In this paper,we define a unital C*-algebra C(cb)*(A,r) and a completely bounded unital homomorphism αr:A → C(cb)*(A,r)with the property that C(cb)*(A,r)=C*(αr(A))and,for every unital C*-algebra B and every unital completely bounded homomorphism φ:A→ B,there is a(unique)unital *-homomorphism π:C(cb)*(A,r)→B such thatφ=πoαr.We prove that,if A is generated by a normal set {tλ:λ∈Λ},then C(cb)*(A,r)is generated by the set {αr(tλ):λ∈Λ}.By proving an equation of the norms of elements in a dense subset of C(cb)*(A,r)we obtain that,if Β is a unital C*-algebra that can be embedded into A,then C(cb)*(B,r)can be naturally embedded into C(cb)*(A,r).We give characterizations of C(cb)*(A,r)for some special situations and we conclude that C(cb)*(A,r)will be "nice" when dim(A)≤ 2 and "quite complicated" when dim(A)≥ 3.We give a characterization of the relation between K-groups of A and K-groups of C(cb)*(A,r).We also define and study some analogous of C(cb)*(A,r). 展开更多
关键词 Completely bounded unital homomorphisms universal C*-algebras K-groups
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Topological Corner States due to Boundary Defects
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作者 Yiqi Zhang Yuwei Hu +1 位作者 Yongdong Li Ce Shang 《Chinese Physics Letters》 2026年第1期44-48,共5页
In conventional higher-order topological insulators(HOTIs),the emergence of topological states can be explained by using the nonzero bulk polarization index.However,corner states emerge in HOTIs with incomplete bounda... In conventional higher-order topological insulators(HOTIs),the emergence of topological states can be explained by using the nonzero bulk polarization index.However,corner states emerge in HOTIs with incomplete boundary unit cells(i.e.,boundary defects)even though the bulk polarization is zero,which challenges the conventional understanding of HOTIs.Here,based on a Kekul´e-distorted honeycomb lattice with incomplete unit cells,we reveal that incomplete unit cells exhibit fractional charges through the analysis of Wannier centers by developing a compensation method and creating the concept of Wannier center domain(WCD)which is the smallest region that one Wannier center occupies.This method compensates for the missing parts of these boundary incomplete unit cells with additional WCDs to make them complete.The compensated WCDs automatically carry the corresponding charge,and this charge together with that of the incomplete unit cell constitutes the total charge of the complete unit cell after compensation.We conclude that the emergence of corner states is attributed to the filling anomaly,which is a fundamental mechanism.Our results refresh the understanding of HOTIs,especially those with structural discontinuities,and provide a novel design for topological states which have application value in producing optical functional devices. 展开更多
关键词 unit cellswe higher order topological insulators topological corner states boundary unit cells ieboundary incomplete unit cells bulk polarization index fractional charges emergence topological states
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Changing Tracks--The new CR450 train, currently in the testing phase, reaches speeds of 450 km/h thanks to technological advances
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作者 GE LIJUN 《ChinAfrica》 2026年第1期51-51,共1页
Safer,smarter,faster...In China,people prefer high-speed trains to flights if the journey time is under five hours.High-speed train travel is set to become even more attractive with the addition of a new member to the... Safer,smarter,faster...In China,people prefer high-speed trains to flights if the journey time is under five hours.High-speed train travel is set to become even more attractive with the addition of a new member to the high-speed train family:the CR450,the world’s fastest electric multiple unit(EMU). 展开更多
关键词 journey time electric multiple unit CR high speed trains FLIGHTS electric multiple unit emu
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Comparison of maximal strength,muscle morphology,and motor unit recruitment and firing rate patterns of the abductor digiti minimi in normal-fat and over-fat males
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作者 Lyric D.Richardson Alex A.Olmos +7 位作者 Allen L.Redinger Stephanie A.Sontag Sunggun Jeon Brenden L.Roth Emma G.High Breanne S.Baker Jerome Hauselle Michael A.Trevino 《Sports Medicine and Health Science》 2026年第2期163-171,共9页
Purpose:This study examined potential differences in strength,muscle morphology,and motor unit(MU)behavior of the abductor digiti minimi(ADM)between normal-fat(NF)and over-fat(OF)males.Methods:Dual-energy X-ray absorp... Purpose:This study examined potential differences in strength,muscle morphology,and motor unit(MU)behavior of the abductor digiti minimi(ADM)between normal-fat(NF)and over-fat(OF)males.Methods:Dual-energy X-ray absorptiometry assessed percent body fat(%BF).Ultrasonography determined muscle cross-sectional area(CSA),echo intensity(EI),and subcutaneous fat(s FAT).MU behavior was assessed during isometric muscle actions at 50%of maximal voluntary contraction(MVC)by analyzing the y-intercepts and slopes for the MU action potential amplitude(MUAPAMP)vs.recruitment threshold(RT)relationships,the A and B terms for the mean firing rate(MFR)vs.RT relationships,and normalized electromyographic amplitude(N-EMGRMS).MU firing times and waveforms were validated with reconstruct-and-test and spike trigger average procedures.Results:%BF was greater for OF(25.70%±5.40%)than NF(16.50%±2.20%;p<0.001).MVC was greater for NF(27.13±7.16)N than OF([19.89±4.96]N;p=0.014).CSA was greater for NF(2.48±0.39)cm^(2)than OF([1.95±0.47]cm^(2);p=0.011).The y-intercepts for the MUAPAMPvs.RT relationships were greater for NF(0.283±0.254)m V than OF([-0.221±0.659]m V;p=0.004).The B terms for the MFR vs.RT relationships were greater for NF(-0.024±0.003)pps/%MVC than OF([-0.031±0.009]pps/%MVC;p=0.038).N-EMGRMSwas similar between groups(p=0.463).Conclusion:Maximal strength,muscle size,and MU recruitment and firing rate patterns for a non-weight bearing muscle differed between normal-fat and over-fat males. 展开更多
关键词 Abductor digiti minimi Body fat ELECTROMYOGRAPHY Motor unit ULTRASONOGRAPHY
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微课驱动小学生英语自主学习能力提升的探究——以Module 5 Unit 9 Where will you go?第一课时自主学习为例
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作者 张兴 《视周刊》 2026年第1期34-35,共2页
一、微课设计:从知识传递到认知建构的范式转变1.微课定义微课是一种以短小精悍的数字视频为主要载体,围绕某个知识点、教学环节或特定教学主题而设计的结构化、情境化教学资源。其时长通常在5-10分钟之间,内容高度聚焦,重点突出,针对性... 一、微课设计:从知识传递到认知建构的范式转变1.微课定义微课是一种以短小精悍的数字视频为主要载体,围绕某个知识点、教学环节或特定教学主题而设计的结构化、情境化教学资源。其时长通常在5-10分钟之间,内容高度聚焦,重点突出,针对性强,符合学生的认知负荷与注意力特点,旨在通过精炼的内容和生动的呈现方式,激发学生学习兴趣,支持个性化、碎片化学习,促进自主探究与合作交流,是现代教育信息化背景下一种重要的教学辅助手段与课程资源形态。 展开更多
关键词 英语 Module 5 Unit 9 能力提升 自主学习 微课
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A Super-Resolution Generative Adversarial Network for Remote Sensing Images Based on Improved Residual Module and Attention Mechanism
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作者 Yifan Zhang Yong Gan +1 位作者 Mengke Tang Xinxin Gan 《Computers, Materials & Continua》 2026年第2期689-707,共19页
High-resolution remote sensing imagery is essential for critical applications such as precision agriculture,urban management planning,and military reconnaissance.Although significant progress has been made in singleim... High-resolution remote sensing imagery is essential for critical applications such as precision agriculture,urban management planning,and military reconnaissance.Although significant progress has been made in singleimage super-resolution(SISR)using generative adversarial networks(GANs),existing approaches still face challenges in recovering high-frequency details,effectively utilizing features,maintaining structural integrity,and ensuring training stability—particularly when dealing with the complex textures characteristic of remote sensing imagery.To address these limitations,this paper proposes the Improved ResidualModule and AttentionMechanism Network(IRMANet),a novel architecture specifically designed for remote sensing image reconstruction.IRMANet builds upon the Super-Resolution Generative Adversarial Network(SRGAN)framework and introduces several key innovations.First,the Enhanced Residual Unit(ERU)enhances feature reuse and stabilizes training through deep residual connections.Second,the Self-Attention Residual Block(SARB)incorporates a self-attentionmechanism into the Improved Residual Module(IRM)to effectivelymodel long-range dependencies and automatically emphasize salient features.Additionally,the IRM adopts amulti-scale feature fusion strategy to facilitate synergistic interactions between local detail and global semantic information.The effectiveness of each component is validated through ablation studies,while comprehensive comparative experiments on standard remote sensing datasets demonstrate that IRMANet significantly outperforms both the baseline and state-of-the-art methods in terms of perceptual quality and quantitative metrics.Specifically,compared to the baseline model,at a magnification factor of 2,IRMANet achieves an improvement of 0.24 dB in peak signal-to-noise ratio(PSNR)and 0.54 in structural similarity index(SSIM);at a magnification factor of 4,it achieves gains of 0.22 dB in PSNR and 0.51 in SSIM.These results confirm that the proposedmethod effectively enhances detail representation and structural reconstruction accuracy in complex remote sensing scenarios,offering robust technical support for high-precision detection and identification of both military and civilian aircraft. 展开更多
关键词 Remote sensing imagery generative adversarial networks SUPER-RESOLUTION enhanced residual unit selfattention mechanism
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Adipose-derived mesenchymal stem cells from solid tissue and lipoaspirates:A comparative study of phenotype,growth,and secretome
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作者 Phuong Thi Minh Dam Dai Dang Nguyen +7 位作者 Anh Thi Thu Ngo Anh Minh Tran Truc Thanh Nguyen Phong Van Nguyen Chi Quynh Nguyen Anh Thi Tuyet Nguyen Quynh-Trang Thi Pham Uyen Thi Trang Than 《World Journal of Stem Cells》 2026年第1期36-48,共13页
BACKGROUND Mesenchymal stem cells(MSCs)are considered a promising therapy for various diseases due to their strong potential in regenerative medicine and immunomodulation.The tissue source of MSCs has gained attention... BACKGROUND Mesenchymal stem cells(MSCs)are considered a promising therapy for various diseases due to their strong potential in regenerative medicine and immunomodulation.The tissue source of MSCs has gained attention for its role in influencing their function,accessibility,and readiness for clinical use.AIM To identify the most suitable adipose source for MSC isolation and expansion for further applications.METHODS We isolated MSCs from solid adipose tissue and liposuction aspirates using the enzyme method.The MSCs were examined for their expansion using population doubling time,differentiation capacity using multilineage differentiation induction,surface markers using flow cytometry,and stability of chromosomes using the karyotyping method.Growth factors and cytokines in MSC-conditioned media were analyzed using the Luminex assay.RESULTS MSCs were isolated from solid adipose tissue and lipoaspirates and expanded from passage 0 to passage 2.All adipose-derived MSCs(AD-MSCs)exhibited the typical elongated,spindle-shaped morphology and comparable proliferation rate.They expressed positive surface markers(cluster of differentiation 73[CD73]:>97%,CD90:>98%,and CD105:>95%),and negative markers(<1%).All MSCs expressed similar levels of stemness genes(octamer-binding transcription factor 4,SRY-box 2,Krüppel-like factor,and MYC),colonyforming,and trilineage differentiation potential.Karyotyping analysis revealed normal chromosomal patterns in all samples,except one sample exhibiting a polymorphism(1qh+).Furthermore,the growth factors and cytokines of hepatocyte growth factor,vascular endothelial growth factor A,interleukin 6(IL-6),and IL-8 were detected in all AD-MSC conditioned media;but fibroblast growth factor-2 and keratinocyte growth factor were selectively expressed in conditioned media from solid or lipoaspirate AD-MSCs,respectively.CONCLUSION These findings indicate that AD-MSCs from both adipose sources possess all of the characteristic features of MSCs with source-specific secretome differences,which are suitable for further expansion and various clinical applications. 展开更多
关键词 Adipose-derived mesenchymal stem cells Adipose tissues Liposuction aspirates Multilineage differentiation Colony-forming units
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Evaluation of the susceptibility to landslide geological disasters based on different slope units and an information content random forest model:a case study of the Longhua District,Shenzhen
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作者 XIONG Haoyu RAN Xiangjin XUE Linfu 《Global Geology》 2026年第1期86-100,共15页
Slope units are divided according to the real topography and have clear geological characteristics,making them ideal units for evaluating the susceptibility to geological disasters.Based on the results of automaticall... Slope units are divided according to the real topography and have clear geological characteristics,making them ideal units for evaluating the susceptibility to geological disasters.Based on the results of automatically and manually corrected hydrological slope unit division,the Longhua District,Shenzhen City,Guangdong Province,was selected as the study area.A total of 15 influencing factors,namely Fluctuation,slope,slope aspect,curvature,topographic witness index(TWI),stream power index(SPI),topographic roughness index(TRI),annual average rainfall,distance to water system,engineering rock group,distance to fault,land use,normalized difference vegetation index(NDVI),nighttime light,and distance to road,were selected as evaluation indicators.The information volume model(IV)and random points were used to select non-geological disaster units,and then the random forest model(RF)was used to evaluate the susceptibility to geological disasters.The automatic slope unit and the hydrological slope unit were compared and analyzed in the random forest and information volume random forest models.The results show that the area under the curve(AUC)values of the automatic slope unit evaluation results are 0.931 for the IV-RF model and 0.716 for the RF model,which are 0.6%(IV-RF model)and 1.9%(RF model)higher than those for the hydrological slope unit.Based on a comparison of the evaluation methods based on the two types of slope units,the hydrological slope unit evaluation method based on manual correction is highly subjective,is complicated to operate,and has a low evaluation accuracy,whereas the evaluation method based on automatic slope unit division is efficient and accurate,is suitable for large-scale efficient geological disaster evaluation,and can better deal with the problem of geological disaster susceptibility evaluation. 展开更多
关键词 geological hazards slope unit information content random forest model susceptibility assessment SHENZHEN
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Correction to:Engineered Extracellular Vesicles Loaded with MiR‑100-5p Antagonist Selectively Target the Lesioned Region to Promote Recovery from Brain Damage
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作者 Yahong Cheng Chengcheng Gai +8 位作者 Yijing Zhao Tingting Li Yan Song Qian Luo Danqing Xin Zige Jiang Wenqiang Chen Dexiang Liu Zhen Wang 《Neuroscience Bulletin》 2026年第2期490-490,共1页
In this article,the unit of total distance in Fig.2B was misused.In fact,the unit of total distance exported by the system was"pixels".After correction,the data in Fig.2B were not changed.The Fig.2B should h... In this article,the unit of total distance in Fig.2B was misused.In fact,the unit of total distance exported by the system was"pixels".After correction,the data in Fig.2B were not changed.The Fig.2B should have appeared as shown below. 展开更多
关键词 selective targeting engineered extracellular vesicles brain damage recovery mir p antagonist pixel unit
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A Data-Driven Framework for Lithium-Ion Battery SOH Estimation Using VMD-GRU Hybrid Approach with Multi-Scale Feature Analysis
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作者 Min Liu Zhengxiong Lu 《Energy Engineering》 2026年第3期232-246,共15页
The accurate state of health(SOH)estimation in lithium-ion batteries represents a critical technological challenge with profound implications for electric vehicle performance and user experience.Precise SOH assessment... The accurate state of health(SOH)estimation in lithium-ion batteries represents a critical technological challenge with profound implications for electric vehicle performance and user experience.Precise SOH assessment not only enables reliable mileage prediction but also ensures operational safety.However,the complex and non-linear capacity fading process during battery cycling poses a challenge to obtaining accurate SOH.To address this issue,this study proposes an effective health factor derived from the local voltage range during the battery charging phase.First,the battery charging phase is divided evenly with reference to voltage intervals,and an importance analysis is conducted on each voltage interval.From these,the voltage interval with the strongest correlation to State of Health(SOH)is extracted as the feature interval.Then,a data-driven framework integrating variational mode decomposition(VMD)with gated recurrent unit(GRU)neural networks enables comprehensive multi-scale temporal feature analysis for enhanced SOH estimation.The methodology begins with rigorous feature engineering to identify and extract optimal health indicators demonstrating superior correlation.Subsequently,the VMD algorithm performs sophisticated signal processing to decompose both the measured capacity and derived health indicators into their constituent intrinsic mode functions and residual components.Finally,a GRU-based neural network is implemented to establish a robust SOH estimation model.Experimental validation using cycling data from different datasets shows that the root mean square error of the estimation results is consistently below 3%,demonstrating the good accuracy and generalisation of the proposed method,using only local data from the charging phase. 展开更多
关键词 Lithium-ion batteries state of health capacity regeneration variational mode decomposition gated recurrent unit
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Investigation of the production of ^(152)Tb and ^(155)Tb terbium radioisotopes with europium targets
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作者 C.Yalçın 《Nuclear Science and Techniques》 2026年第2期183-193,共11页
In recent years,terbium radioisotopes have been investigated for their potential therapeutic and diagnostic applications in nuclear medicine.This study aimed to investigate the production of ^(152) Tb and ^(155) Tb by... In recent years,terbium radioisotopes have been investigated for their potential therapeutic and diagnostic applications in nuclear medicine.This study aimed to investigate the production of ^(152) Tb and ^(155) Tb by alpha-induced reactions in detail,with a specific focus on determining the optimum production parameters and testing existing nuclear models.Given the limited number of experiments conducted on reactions related to terbium isotope production,it is necessary to perform theoretical calculations of cross sections over a wide energy range to gain a detailed understanding of terbium isotope production.To achieve this objective,the cross sections of the ^(151)Eu(α,n)^(154) Tb reactions were calculated up to 60 MeV using the TALYS computer code with 432 different combinations of optical model parameters,level density,and strength function models.The theoretical reaction cross-section results were compared with the experimental results in the literature.The best input parameters were determined using the Threshold Logic Unit method,and these parameters were used in all isotope production calculations.Once the optimal model combination was determined,the total activity production and isotopic fraction of ^(152) Tb and ^(155) Tb isotopes were calculated in detail for beam energies of 17–50 MeV,different irradiation times,and varying ^(151) Eu and ^(153) Eu target thicknesses. 展开更多
关键词 Terbium radioisotopes Medical isotope production Alpha-induced reactions Cross section Threshold logic unit method
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Ultra-broadband acoustic logic gate based on passive phase manipulation
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作者 Yu-Han Xia Nai-Qi Pang +2 位作者 Yin Wang Long-Xu Wang Yong Ge 《Chinese Physics B》 2026年第1期514-520,共7页
In recent years,acoustic logic gates has attracted growing interest in acoustics due to their promising applications in acoustic communication and signal processing.For practical implementation,these logic gates must ... In recent years,acoustic logic gates has attracted growing interest in acoustics due to their promising applications in acoustic communication and signal processing.For practical implementation,these logic gates must operate over a certain bandwidth to ensure reliable performance.However,current experimental realizations have predominantly been confined to single-frequency or narrowband operation,leaving their broadband capabilities largely unverified.To address this gap,we present both numerical and experimental demonstrations of three basic acoustic logic gates(OR,NOT,and AND)using a phased unit cell composed of a central channel flanked by two arrays of semicircular cavities.By leveraging phase modulation of the unit cells and linear interference of sound,we achieve these logic operations with a uniform threshold of I_(t)=0.25.Remarkably,the measured fractional bandwidths(bandwidth relative to center frequency)reach approximately 111.5%(OR),37.2%(NOT),and 48.5%(AND),demonstrating ultra-broadband functionality.The proposed logic gates combine exceptional bandwidth with structural simplicity,offering significant potential for applications in acoustic computing,information processing,and integrated acoustic systems. 展开更多
关键词 acoustic logic gate ultra-broad band phased unit cell
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AC Fault Characteristic Analysis and Fault Ride-through of Offshore Wind Farms Based on Hybrid DRU-MMC
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作者 Haokai Xie Yi Lu +5 位作者 Xiaojun Ni Yilei Gu Sihao Fu Wenyao Ye Zheren Zhang Zheng Xu 《Energy Engineering》 2026年第2期184-205,共22页
With the rapid development of large-scale offshore wind farms,efficient and reliable power transmission systems are urgently needed.Hybrid high-voltage direct current(HVDC)configurations combining a diode rectifier un... With the rapid development of large-scale offshore wind farms,efficient and reliable power transmission systems are urgently needed.Hybrid high-voltage direct current(HVDC)configurations combining a diode rectifier unit(DRU)and a modular multilevel converter(MMC)have emerged as a promising solution,offering advantages in cost-effectiveness and control capability.However,the uncontrollable nature of the DRU poses significant challenges for systemstability under offshore AC fault conditions,particularly due to its inability to provide fault current or voltage support.This paper investigates the offshore AC fault characteristics and fault ride-through(FRT)strategy of a hybrid offshore wind power transmission system based on a diode rectifier unit DRU and MMC.First,the dynamic response of the hybrid system under offshore symmetrical three-phase faults is analyzed.It is demonstrated that due to the unidirectional conduction nature of the DRU,its AC current rapidly drops to zero during faults,and the fault current is solely contributed by the wind turbine generators(WTGs)and wind farm MMC(WFMMC).Based on this analysis,a coordinated FRT strategy is proposed,which combines a segmented current limiting control for the wind-turbine(WT)grid-side converters(GSCs)and a constant AC current control for the WFMMC.The strategy ensures effective voltage support during the fault and prevents MMC current saturation during fault recovery,enabling fast and stable system restoration.Electromagnetic transient simulations in PSCAD/EMTDC verify the feasibility of the proposed fault ride-through strategy. 展开更多
关键词 Diode rectifier unit offshore AC fault analysis fault ride-through coordinate control
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Towards a Cooperative Global Future——China’s Global Governance Initiative lays emphasis on concrete actions aimed at promoting peace and development rather than on symbolic declarations
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作者 BUSANI NGCAWENI 《ChinAfrica》 2026年第2期16-17,共2页
As we enter the year 2026,the international system continues to receive shocks from Donald Trump,arguably the 21st century’s most disruptive US leader.His return to the White House in 2025 coincided with the 80th ann... As we enter the year 2026,the international system continues to receive shocks from Donald Trump,arguably the 21st century’s most disruptive US leader.His return to the White House in 2025 coincided with the 80th anniversary of the defeat of fascism and the establishment of the United Nations,the multilateral platform that carried the world’s hope for peace,restraint and collective security.The coincidence was unsettling.A world order designed to limit power now confronts a moment in which power is exercised openly,transactionally and unapologetically. 展开更多
关键词 multilateral platform cooperative global future development Donald Trump united nationsthe PEACE Chinas global governance initiative symbolic declarations
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