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Particle Distribution Informed by Chain Rigidity in Diblock Copolymer Melts: The Effect of Entropy

Chinese Journal of Polymer Science 2024年第3期42卷 388-399,I0009页

作者： Yuguo chen Shuanhu Qi ying Jiang School of Chemistry Beihang UniversityBeijing 100191China

We study the effect of chain rigidity on tailoring the nanoparticle locations for neutral and selective particles embedded in the lamellar morphology formed by semiflexible diblock copolymer chains using self-consistent field calculations. The nanoparticles are modeled through a cavity function, and the semiflexible chains are represented by the continuous Kratsky-Porod chain model. In general situation, the nanoparticles prefer to stay at the interface in order to reduce the interface areas and thus the system free energy. However, the particle distribution at the domain center is subtle, and the underlying physics is intrinsically different depending on the polymer flexibility. In the case of flexible chains, the entropy just contributes a constant shift to the free energy when the nanoparticles move around the domain center indicating that the local metastable state if appears at the domain center is wholly attributed to the local minimum in the enthalpy. If the polymers are rigid, the variation of the particle distribution at the domain center has a close relation with the polymer rigidity and nanoparticle size. In the case of strongly rigid polymers with small nanoparticles, a nearly uniform particle distribution at the domain center is observed, while in other cases, a local enhancement of particle distribution there is found. In contrast to the case of flexible chains, further analysis reveals the crucial role of entropy in controlling the shape of particle distributions at the phase domain. Specifically, the local metastable state appears in the domain center is determined by the large entropy there which arises from the weak coupling of bond orientations that allows the polymer chains to be relatively relaxed. When the particle becomes selective, its distribution in the phase domain exhibits a shift almost uniformly rather than changes its profile, and the underlying physics still holds. In all, our study establishes a strong coupling between the chain rigi

关键词： Semiflexible diblock copolymer Nanoparticle distribution Self-consistent field theory Entropic effect

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Small-signal Stability Criteria in Power Electronics-dominated Power Systems:A Comparative Review

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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1003-1018页

作者： Qifan chen Siqi Bu Chi Yung chung Department of Electrical and Electronic Engineer The Hong Kong Polytechnic UniversityHong KongChina Department of Electrical and Electronic Engineering Shenzhen Research InstituteCentre for Grid ModernisationInternational Centre of Urban Energy NexusCentre for Advances in Reliability and SafetyResearch Institute for Smart Energyand Policy Research Centre for Innovation and TechnologyThe Hong Kong Polytechnic UniversityHong KongChina

To tackle emerging power system small-signal stability problems such as wideband oscillations induced by the large-scale integration of renewable energy and power electronics,it is crucial to review and compare existing small-signal stability analysis *** this basis,guidance can be provided on determining suitable analysis methods to solve relevant small-signal stability problems in power electronics-dominated power systems(PEDPSs).Various mature methods have been developed to analyze the small-signal stability of PEDPSs,including eigenvalue-based methods,Routh stability criterion,Nyquist/Bode plot based methods,passivity-based methods,positive-net-damping method,lumped impedance-based methods,bifurcation-based methods,*** this paper,the application conditions,advantages,and limitations of these criteria in identifying oscillation frequencies and stability margins are reviewed and compared to reveal and explain connections and discrepancies among ***,efforts are devoted to mathematically proving the equivalence between these small-signal stability ***,the performance of these criteria is demonstrated and compared in a 4-machine 2-area power system with a wind farm and an IEEE 39-bus power system with 3 wind farms.

关键词： Impedance-based method oscillation analysis power electronic converter power electronics-dominated power system renewable power generation small-signal stability

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Revealing Tissue Heterogeneity and Spatial Dark Genes from Spatially Resolved Transcriptomics by Multiview Graph Networks

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Research 2024年第2期6卷 629-645页

作者： ying Li Yuejing Lu chen Kang Peiluan Li Luonan chen School of Mathematics and Statistics Henan University of Science and TechnologyLuoyang471023China Longmen Laboratory LuoyangHenan471003China Key Laboratory of Systems Biology Institute of Biochemistry and Cell BiologyCenter for Excellence in Molecular Cell ScienceChinese Academy of SciencesShanghai201100China Key Laboratory of Systems Health Science of Zhejang Province Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou310000China School of Life Science and Technology ShanghaiTech UniversityShanghai201100.China

Spatially resolved transcriptomics(SRT)is capable of comprehensively characterizing gene expression patterns and providing an unbiased image of spatial *** fully understand the organizational complexity and tumor immune escape mechanism,we propose stMGATF,a multiview graph attention fusion model that integrates gene expression,histological images,spatial location,and gene *** better extract information,stMGATF exploits SimCLRv2 for visual feature exaction and employs edge feature enhanced graph attention networks for the learning potential embedding of each view.A global attention mechanism is used to adaptively integrate 3 views to obtain low-dimensional *** to diverse SRT datasets,stMGATF is robust and outperforms other methods in detecting spatial domains and denoising data even with different resolutions and *** particular,stMGATF contributes to the elucidation of tissue heterogeneity and extraction of 3-dimensional expression ***,considering the associations between genes in tumors,stMGATF can identify the spatial dark genes ignored by traditional methods,which can be used to predict tumor-driving transcription factors and reveal tumor immune escape mechanisms,providing theoretical evidence for the development of new immunotherapeutic strategies.

关键词： Spatial integrate driving

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The joint Laplace transforms for killed diffusion occupation times

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Applied Mathematics(A Journal of Chinese Universities) 2024年第3期39卷 398-415页

作者： LI ying-qiu chen Ye School of Mathematics and Statistics Changsha University of Science and TechnologyChangsha 410114China College of Mathematics and Computational Science Hunan University of Arts and ScienceChangde 415000China

The approach of Li and Zhou(2014)is adopted to find the Laplace transform of occupation time over interval(0,a)and joint occupation times over semi-infinite intervals(-∞,a)and(b,∞)for a time-homogeneous diffusion pr... 详细信息

关键词： time-homogeneous diffusion process occupation time joint occupation time Laplace transform Brownian motion with drift

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Effects of dimethyl ether and ethanol additions on soot transition in ethylene counterflow diffusion flames

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Science China(Technological Sciences) 2024年第4期67卷 1094-1112页

作者： GUO LinGe ying YaoYao chen chen ZHAO Xuan LIU Dong MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power EngineeringNanjing University of Science and TechnologyNanjing 210094China Advanced Combustion Laboratory School of Energy and Power EngineeringNanjing University of Science and TechnologyNanjing 210094China

This paper investigates the effect of blending dimethyl ether(DME)and ethanol on the soot transition periods in ethylene counterflow diffusion flames by using a novel optical diagnostic *** soot critical transition point in different conditions is identified experimentally and *** kinds of flames are carried out to gain the soot critical transition point in counterflow diffusion flames by changing oxygen fraction(Xo)and changing volume flow rates of fuel and oxidizer(Qv).The red-green-blue(RGB)ratio method is used to precisely identify the soot critical transition point,and chemical kinetic simulations are performed to analyze the detailed reaction *** results show that compared to the ethylene flame,the soot critical transition point occurs at a higher Xoand a lower Qvwhen DME or ethanol is *** addition of DME and ethanol can inhibit soot formation,due to the degree of soot formation reaction being lower than the degree of the oxidation reaction in the blending flames.

关键词： optical diagnosis sooting tendency counterflow diffusion flame dimethyl ether ethanol

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Analytical computation of magnetic field in coil-dominated superconducting quadrupole magnets based on racetrack coils

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Nuclear Science and Techniques 2024年第4期35卷 119-135页

作者： Chuang Shen ying-Shun Zhu Fu-San chen China Spallation Neutron Source Institute of High Energy PhysicsChinese Academy of Sciences1 Zhongziyuan RoadDongguan 523000China Institute of High Energy Physics Chinese Academy of Sciences19B Yuquan RoadBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China

Currently,three types of superconducting quadrupole magnets are used in particle accelerators:cos 2θ,CCT,and ***,all three coil configurations have complex spatial geometries,which make magnet manufacturing and strain-sensitive superconductor applications *** with the three existing quadrupole coils,the racetrack quadrupole coil has a simple shape and manufacturing process,but there have been few theoretical *** this paper,the two-dimensional and three-dimensional analytical expressions for the magnetic field in coil-dominated racetrack superconducting quadrupole magnets are *** analytical expressions of the field harmonics and gradient are fully resolved and depend only on the geometric parameters of the coil and current ***,a genetic algorithm is applied to obtain a solution for the coil geometry parameters with field harmonics on the order of 10^(-4).Finally,considering the practical engineering needs of the accelerator interaction region,electromagnetic design examples of racetrack quadrupole magnets with high gradients,large apertures,and small apertures are described,and the application prospects of racetrack quadrupole coils are analyzed.

关键词： Superconducting quadrupole magnet Racetrack coil Multipole field Genetic algorithm Magnetic design

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Single-Ni-atoms on nitrogenated humic acid based porous carbon for CO_(2) electroreduction

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Frontiers of Chemical Science and Engineering 2024年第5期18卷 37-47页

作者： Delei Yu ying chen Yao chen Xiangchun Liu Xianwen Wei Ping Cui Anhui Key Laboratory of Coal Clean Conversion&Utilization School of Chemistry and Chemical EngineeringAnhui University of TechnologyMa’anshan 243002Chin

tWe proposed a facile synthesis of single-Ni-atom catalysts on low-cost porous carbon using a calcina-tion method at the temperatures of 850-1000°C,which were used for CO_(2) electrochemical reduction to *** porous carbon was prepared by carbonizing cheap and abundant humic *** structural characterizations of the as-synthesized catalysts and their electrocatalytic performances were *** results showed that the single-Ni-atom catalyst activated at 950°C showed an optimum catalytic performance,and it reached a CO Faradaic efficiency of 91.9% with a CO partial current density of 6.9 mAcm^(-2)at-0.9 V *** hydrogen electrode(RHE).Additionally,the CO Faradaic efficiency and current density of the optimum catalyst changed slightly after 8 h of continuous operation,suggesting that it possessed an excellent *** structure-activity relations indicate that the variation in the CO_(2) electroche-mical reduction performance for the as-synthesized catalysts is ascribed to the combined effects of the increase in the content of pyrrolic N,the evaporation of Ni and N,the decrease in pore volume,and the change in graphitization degree.

关键词： CO_(2) electroreduction single-Ni-atom cataly-sts humic acid based porous carbon

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Stretchable and self-healing conductive fibers from hierarchical silver nanowires-assembled network

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Nano Research 2024年第2期17卷 763-770页

作者： ying-ying Wu Hong chen Fan Zhang Pan Guo Haili Qin Huai-Ping Cong Anhui Province Key Laboratory of Advanced Catalytic Materials and Reaction Engineering School of Chemistry and Chemical EngineeringHefei University of TechnologyHefei 230009China

Conductive fibers(CFs)with features of high conductivity,stretchability,self-healability,and electromechanical stability are key components of the increasingly popular wearable ***,since the lack of structural design of conductive network and interfacial interaction between soft polymer and conductive additives,it is still hard to enable CFs to meet above ***,we describe a facial drawing method from a hydrogel reservoir which is remolded into ultrathin and stretchable CFs with excellent multi-responsive *** hydrogel reservoir was fabricated in synergy of an ice-templating method and in situ polymerization using the assembled framework as a *** on the effective fabrication mechanism,the diameter of CFs could be well-tuned from 90 to 400μm by adjusting the dipping depth of the glass rod,accompanied with conductivity increased from 0.75 to 2.5 S/*** the hierarchical network structure was well maintained in the CFs,professional performances have been proved on the stretchability and electromechanical *** presence of massive hydrogen bonding and Ag–S bond enabled the CFs with excellent self-healability under the conditions of contact,electric field,and near infrared light,***,the CFs with high sensing property could be integrated into an advanced textile sensor through an effective healing-induced integration strategy,demonstrating its great potentials as superior two-dimensional(2D)electronic skins.

关键词： conductive fibers self-assembled silver nanowires Ag–S coordination self-healing flexible sensors

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Predator-prey encounters:deciphering the robbery relationship between highwayman flies and their ant victims

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Integrative Zoology 2024年第2期19卷 253-261页

作者： ying ZHAO Yulong YU Zhi chen ying LI Huidan TENG Guillaume CHOMICKI Chuntian ZHANG Gao chen Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations KunmingChina CAS Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunmingChina College of Life Science Shenyang Normal UniversityShenyangChina School of Ecology and Environmental Science Yunnan UniversityKunmingChina University of Chinese Academy of Sciences BeijingChina Ecology and Evolutionary Biology School of BiosciencesAlfred Denny BuildingUniversity of SheffieldWestern BankSheffieldUK

Examples of predator–prey interactions in which flies rob ants are *** date,this behavior has only been recorded in the genus Bengalia Robineau-Desvoidy(Bengaliinae,Diptera,Calliphoridae).These predatory flies ambush ants,and rob them of the food or offspring that they are ***,because of the rarity of this behavior,the reasons and consequences(evolutionary advantages)are unknown,and indeed,the behavior has been sometimes considered *** this study,we employed field investigations and behavioral analyses to investigate whether the sex of the fly Bengalia varicolor,or the weight and quality of the food carried by Pheidole nodus ants influenced fly–ant interactions in their natural *** show that food weight and quality influenced the behavior of *** independent of the fly’s *** behavior by the flies was more successful when the food robbed was of high-quality and light in ***,the weight of the food robbed modulated the escape distance the flies could carry *** then may affect the food quality and weight transported by the *** is a novel example of deciphering the relationship between highwayman flies and their ant *** the widespread distribution of Bengalia flies,we suggest that such interspecific predator–prey encounters may shape the robbery interactions and the carrying behavior of further ant species in nature.

关键词： Bengalia kleptoparasitism Pheidole predatory flies robbing

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A Deep Learning Framework for Mass-Forming Chronic Pancreatitis and Pancreatic Ductal Adenocarcinoma Classification Based on Magnetic Resonance Imaging

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Computers, Materials & Continua 2024年第4期79卷 409-427页

作者： Luda chen Kuangzhu Bao ying chen Jingang Hao Jianfeng He Faculty of Information Engineering and Automation Kunming University of Science and TechnologyKunming650504China Department of Radiology Second Affiliated Hospital of Kunming Medical UniversityKunming650101China School of Physics and Electronic Engineering Yuxi Normal UniversityYuxi653100China

Pancreatic diseases, including mass-forming chronic pancreatitis (MFCP) and pancreatic ductal adenocarcinoma(PDAC), present with similar imaging features, leading to diagnostic complexities. Deep Learning (DL) methodshave been shown to perform well on diagnostic tasks. Existing DL pancreatic lesion diagnosis studies basedon Magnetic Resonance Imaging (MRI) utilize the prior information to guide models to focus on the lesionregion. However, over-reliance on prior information may ignore the background information that is helpful fordiagnosis. This study verifies the diagnostic significance of the background information using a clinical ***, the Prior Difference Guidance Network (PDGNet) is proposed, merging decoupled lesion andbackground information via the Prior Normalization Fusion (PNF) strategy and the Feature Difference Guidance(FDG) module, to direct the model to concentrate on beneficial regions for diagnosis. Extensive experiments inthe clinical dataset demonstrate that the proposed method achieves promising diagnosis performance: PDGNetsbased on conventional networks record an ACC (Accuracy) and AUC (Area Under the Curve) of 87.50% and89.98%, marking improvements of 8.19% and 7.64% over the prior-free benchmark. Compared to lesion-focusedbenchmarks, the uplift is 6.14% and 6.02%. PDGNets based on advanced networks reach an ACC and AUC of89.77% and 92.80%. The study underscores the potential of harnessing background information in medical imagediagnosis, suggesting a more holistic view for future research.

关键词： Pancreatic cancer pancreatitis background region prior normalization fusion feature difference guidance

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