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Holevo bound independent of weight matrices for estimating two parameters of a qubit

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Chinese Physics B 2024年第2期33卷 137-143页

作者：牛畅郁司夏 Department of Modern Physics&hefei national Research Center for physical sciences at the microscale and School of physical sciences University of Science and Technology of ChinaHefei 230026China hefei national laboratory University of Science and Technology of ChinaHefei 230088China

Holevo bound plays an important role in quantum metrology as it sets the ultimate limit for multi-parameter estimations,which can be asymptotically *** for some trivial cases,the Holevo bound is implicitly defined and formulated with the help of weight *** we report the first instance of an intrinsic Holevo bound,namely,without any reference to weight matrices,in a nontrivial ***,we prove that the Holevo bound for estimating two parameters of a qubit is equivalent to the joint constraint imposed by two quantum Cramér–Rao bounds corresponding to symmetric and right logarithmic *** weightless form of Holevo bound enables us to determine the precise range of independent entries of the mean-square error matrix,i.e.,two variances and one covariance that quantify the precisions of the estimation,as illustrated by different estimation *** result sheds some new light on the relations between the Holevo bound and quantum Cramer–Rao *** generalizations are discussed.

关键词： quantum metrology quantum Fisher information Holevo bound quantum multi-parameter estimation

Efficient synthesis of bottle-brush polymers enabled by selective photoactivation strategy in NIR-induced PET-RAFT polymerization

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science China Chemistry 2024年第7期67卷 2353-2361页

作者： Hao Zha Lin Cheng Zuowei Wang Chao Liu Chunyan Hong Department of Polymer science and Engineering University of Science and Technology of ChinaHefei 230026China hefei national laboratory for physical sciences at the microscale University of Science and Technology of ChinaHefei 230026China

Bottle-brush polymers possessing densely grafted side chains have special properties that are distinct from linear ***,an efficient method for preparing bottle-brush polymers based on a selective photoactivation strategy in the photoinduced electron/energy transfer reversible addition-fragmentation chain transfer(PET-RAFT)polymerization was developed.A methacrylate monomer 2-(2-(dodecylthiocarbonothioylthio)propionate)ethyl methacrylate(DTPEMA)containing a 2-(dodecylthiocarbonothioylthio)propionate(DTP)unit with a secondary R group was *** the unique selectivity of metal naphthalocyanine photocatalyst zinc 2,11,20,29-tetra-tert-butyl-2,3-naphthalocyanine(ZnTtBNc)toward trithiocarbonate with tertiary R group,the PET-RAFT polymerization of DTPEMA catalyzed by ZnTtBNc was performed under near infrared(NIR)light(λ_(max)=760 nm)irradiation at room temperature,using 4-cyano-4-[(dodecylsulfanylthiocarbonyl)-sulfanyl]pentanoic acid(CDTPA)with a tertiary R group as a chain transfer agent(CTA).Proton nuclear magnetic resonance(1H NMR)and gel permeation chromatography(GPC)results demonstrated that the DTP units in the side chains were inert during the *** grafting poly(methyl acrylate)(PMA)from PDTPEMA via thermal-initiated RAFT polymerization,welldefined P(DTPEMA-g-PMA)bottle-brush polymers could be ***,the film prepared from the bottle-brush polymer exhibited excellent scratch self-healing property due to the interlocking of side chains.

关键词： bottle-brush polymers PET-RAFT polymerization selective photoactivation scratch self-healing

Advances in bio-inspired electrocatalysts for clean energy future

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Nano Research 2024年第2期17卷 515-533页

作者： Jing-Wen Duan Mu Min-Rui Gao Division of Nanomaterials&Chemistry Hefei National Laboratory for Physical Sciences at the MicroscaleDepartment of ChemistryUniversity of Science and Technology of ChinaHefei 230026China

Electrocatalysis can enable efficient energy storage and conversion and thus is an effective way to achieve carbon *** unique structure and function of organisms can offer many ideas for the design of electrocatalysts,which has become one of the most promising research ***,the understanding of the mechanism of bio-inspired electrocatalysis has become clearer,which has promoted the design of bio-inspired catalysts and catalytic *** bio-inspired catalysts(enzyme-like catalysts,layered porous catalysts,superhydrophobic/superhydrophilic surfaces,and so on)have been developed to enable efficient electrocatalytic ***,we discuss the key advances in the field of bio-inspired electrocatalysts progressed in recent ***,the role of bio-inspiration in increasing the intrinsic activity and number of active sites of catalysts is ***,the structure and mechanism of layered porous catalytic systems that mimic biological transport systems are comprehensively ***,the design of three-phase interfaces from micro-nanoscale to atomic scale is highlighted,including the wettability of the electrode surface and the transport system near the *** conclude the review by identifying challenges in bio-inspired electrocatalysts and providing insights into future prospects for the exciting research field.

关键词： bio-inspired electrocatalysts active sites layered porous structure three-phase interface

Experimental Proposal on Non-Hermitian Skin Effect by Two-dimensional Quantum Walk with a Single Trapped Ion

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Chinese Physics Letters 2024年第4期41卷 19-24页

作者：侯琬儿唐皓许勤林毅恒 CAS Key laboratory of microscale Magnetic Resonance and School of physical sciences University of Science and Technology of ChinaHefei 230026China hefei national laboratory University of Science and Technology of ChinaHefei 230088China

Non-Hermitian Hamiltonians are widely used in describing open systems with gain and loss,among which a key phenomenon is the non-Hermitian skin *** we report an experimental scheme to realize a twodimensional(2D)discrete-time quantum walk with non-Hermitian skin effect in a single trapped *** is shown that the coin and 2D walker states can be labeled in the spin of the ion and the coherent-state lattice of the ion motion,*** numerically observe a directional bulk flow,whose orientations are controlled by dissipative parameters,showing the emergence of the non-Hermitian skin *** then discuss an experimental implementation of our scheme in a laser-controlled trapped Ca^(+)*** experimental proposal may be applicable to research of dissipative quantum walk systems and may be able to generalize to other platforms,such as superconducting circuits and atoms in cavity.

关键词： effect dissipative quantum

Synthesis of hierarchically porous carbon materials by zinc salts-assisted carbonization of biomass and organic solid wastes

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Particuology 2024年第1期84卷 45-52页

作者： Le-Le Zhang Lei Tong Yanwei Ding Wanqun Zhang Hai-Wei Liang hefei national Research Center for physical sciences at the microscale Department of ChemistryUniversity of Science and Technology of ChinaHefei230026China

Hierarchically porous carbons(HPCs)with multimodal pores have attracted considerable attention due to their unique physical and chemical properties and various application potentials in heterogeneous catalysis,environmental treatment,and energy storage and ***,we report a general and simple zinc salts-assisted method for the synthesis of HPCs with varied porosity and chemical func-tionalities by the direct carbonization of diverse biomass and *** the carbonization,zinc salts are thermally decomposed into nanoparticles that serve as in-situ templates to introduce nanopores in *** prepared HPCs exhibit high specific surface areas(up to 2432 m2 g-1),large pore volumes(up to 4.30 cm^(3)g^(-1)),and broad pore size ***,the zinc salts can be recovered and recycled,supporting the sustainable production of HPCs on large *** prepared HPCs-supported catalysts with atomically dispersed metal sites exhibit promising electrocatalytic performance for the oxygen reduction reaction.

关键词： Hierarchical porous carbon Zinc salts Biomass Wastes Electrocatalysis

Two-dimensional semiconductor heterostructures for photocatalytic CO_(2)conversion

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science China Chemistry 2024年第8期67卷 2434-2447页

作者： Yang Wu Mingyu Wu Yongfu Sun Yi Xie hefei national Research Center for physical sciences at microscale University of Science and Technology of ChinaHefei 230026China

The CO_(2)reduction into carbon-contained fuel via solar energy offers the powerful tools to realize the zero-emission carbon *** to the intriguing features of the two-dimensional(2D)heterostructures,it is susceptible to modulate the electronic structure as well as the surface geometry for optimizing the photocatalytic CO_(2)*** this perspective,we surveyed the fundamental insights of 2D semiconductor heterostructures,involving the fabrication strategies and classification of the 2D semiconductor ***,we have detailly discussed the overview of 2D semiconductor heterostructure for optimizing CO_(2)photocatalytic influenced factors,including the solar energy utilization,photogenerated carriers separation,and redox reaction ***,we showed the significant advantages of 2D heterostructures in elevating CO_(2)photoreduction performance,focusing on activity,selectivity and *** analyzing the limitations and developments,we ended by putting forward insights into the further researches about the CO_(2)photocatalysts and reactor design,even industrial applications.

关键词： two-dimensional semiconductor heterostructures photocatalysis CO_(2)conversion

Preparing cyclic polymers at high concentrations via self-folding cyclization technique by adjusting the contents of hydrophilic units in linear precursors

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Chinese Chemical Letters 2024年第2期35卷 283-288页

作者： Hao Zha Zuowei Wang Chao Liu Chunyan Hong Department of Polymer science and Engineering University of Science and Technology of ChinaHefei 230026China hefei national laboratory for physical sciences at the microscale University of Science and Technology of ChinaHefei 230026China

Cyclic polymers are a class of polymers that feature endless topology,and the synthesis of cyclic polymers has attracted the attention of many ***,cyclic polymers were efficiently constructed by self-folding cyclization technique at high *** poly((oligo(ethylene glycol)acrylate)-co-(dodecyl acrylate))(P(OEGA-co-DDA))precursors with different ratios of hydrophilic and hydrophobic moieties were synthesized by reversible addition-fragmentation chain transfer(RAFT)polymerization using a bifunctional chain transfer agent with two anthryl end *** amphiphilic linear precursors underwent the self-folding process to generate polymeric nanoparticles in *** irradiating the aqueous solution of the nanoparticles with 365 nm UV light,cyclic polymers were synthesized successfully via coupling of anthryl *** effects of the ratios of hydrophilic and hydrophobic moieties in linear P(OEGA-co-DDA)copolymers and polymer concentration on the purity of the obtained cyclic polymers were explored in detail via ^(1)H nuclear magnetic resonance(^(1)H NMR),dynamic light scattering(DLS),UV‒visible(vis)analysis,three-detection size exclusion chromatography(TD-SEC)and transmission electron microscopy(TEM).It was found that by adjusting the content of the hydrophilic segments in linear precursors,single chain polymeric nanoparticles(SCPNs)can be generated at high polymer ***,cyclic polymers with high purity can be constructed *** method overcomes the limitation of traditional ring-closure method,which is typically conducted in highly dilute conditions,providing an efficient method for the scalable preparation of cyclic polymers.

关键词： Cyclic polymers Self-folding cyclization technique Single chain polymeric nanoparticles RAFT polymerization Direct visualization

Absolute partial and total ionization cross sections of carbon monoxide with electron collision from 350 eV to 8000 eV

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Chinese Physics B 2024年第4期33卷 459-464页

作者： Taj Wali Khan 黄伟哲王恩亮单旭陈向军 hefei national Research Center of physical sciences at the microscale and Department of Modern Physics University of Science and Technology of ChinaHefei 230026China

The absolute partial and total cross sections for electron impact ionization of carbon monoxide are reported for electron energies from 350 eV to 8000 *** product ions(CO^(+),C^(+),O^(+),CO^(2+),C^(2+),and O^(2+))are measured by employing an ion imaging mass spectrometer and two ion-pair dissociation channels(C^(+)+O^(+)and C^(2+)+O^(+))are *** absolute cross sections for producing individual ions and their total,as well as for the ion-pair dissociation channels are obtained by normalizing the data of CO^(+)to that of Ar^(+)from CO-Ar mixture target with a fixed 1:1 *** overall errors are evaluated by considering various kinds of uncertainties.A comprehensive comparison is made with the available data,which shows a good agreement with each other over the energy ranges that are *** work presents new cross-section data with electron energies above 1000 eV.

关键词： electron impact ionization cross sections carbon monoxide ion imaging mass spectrometer

Confluence of asymmetric catalysis and electrosynthesis in sustainable chemical transformations

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science China Chemistry 2024年第3期67卷 755-758页

作者： Qinglin Zhang Kang Liang Chang Guo hefei national Research Center for physical sciences at the microscale and Department of Chemistry University of Science and Technology of ChinaHefei 230026China

Electrosynthesis has gained widespread recognition for its extraordinary ability to precisely control the redox *** outstanding capability enables the direct conversion of non-functionalized substrates into reactive intermediates by utilizing easily accessible starting materials, eliminating the need for preliminary functionalization procedures and allowing for unconventional bond activations.

关键词： Confluence of asymmetric catalysis and electrosynthesis in sustainable chemical transformations