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An improved construction algorithm of polar codes based on the frozen bits

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Optoelectronics Letters 2024年第3期20卷 157-162页

作者： yuAN Jianguo zhang Fengguo yu Linfeng PANG yu School of Optoelectronic Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China

In order to improve the problems that the minimum hamming weight(MHW) of the polar codes of the traditional Gaussian approximation(GA) construction is small and its performance is not good enough, an improved channel construction algorithm of polar codes based on frozen bits is proposed by combining the construction of the Reed-Muller(RM) code to effectively increase the MHW and analyzing the correcting and checking functions of the frozen bits in the successive cancellation list(SCL) decoding.

关键词： polar algorithm successive

Investigation on the vortical structures by the Liutex method in turbulent channels at Re_(τ)=180 with scalloped and triangular riblet control

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Journal of Hydrodynamics 2024年第1期36卷 35-52页

作者： zhang-dan yu Shang Jiang Hai-dong yu Bi-yu Pang Xin Dong Yi-qian Wang School of Mathematical Sciences Soochow UniversitySuzhou215006China Beijing Institute of Astronautical System Engineering Beijing100076China

Riblets are a series of small protrusions formed along the flow direction,which have been extensively studied as a passive turbulent drag reduction *** and numerical simulations have shown that well-designed riblets can significantly reduce drag in turbulent flows,making them highly promising and valuable for various *** this study,we focus on a scalloped riblet,which is designed by smoothly connecting two third-order polynomials,and thus the sharpness of the tip and the curvature of the valley can be well *** conduct direct numerical simulations of turbulent channel with smooth plate,scalloped riblet-mounted and triangular riblet-mounted *** in wall units of W^(+)=20 and height-width ratio ofγ=0.5 are selected for both riblet *** with the smooth plate case,the scalloped riblet case achieves an 8.68%drag reduction,while the triangular riblet case achieves a 4.79%drag *** obtained drag reduction rate of the triangular riblet is consistent with previous experiments and simulations,and the results indicate that the scalloped riblet is more effective in reducing drag and deserves further *** compare turbulent statistics of the scalloped riblet case with those of the triangular riblet *** mean velocity profiles of riblets are similar,but both the Reynolds shear stress and second-order statistics of velocity fluctuations and Liutex are significantly reduced in the scalloped riblets controlled turbulent channel,indicating that the scalloped riblet can more effectively suppress the spanwise and wall-normal turbulent intensity near the *** also compare the pre-multiplied spectra of streamwise velocity and streamwise Liutex component for the three cases to investigate the energy distribution and characteristics of Liutex *** Liutex vortex identification method is also utilized to analyze the instantaneous flow field,which provides insights into the flow field and could be bene

关键词： Liutex vector riblet drag reduction tip sharpness turbulent channel scalloped

Cyclodextrin nanofilms with hydrophobic and hydrophilic channels for solvent permeation and molecular sieving

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Nano Research 2024年第7期17卷 6638-6644页

作者： Kai zhang yu Dai Yongli Shi Zhaoxin zhang Linji Li Xiaojin zhang Fan Xia Faculty of Materials Science and Chemistry China University of GeosciencesWuhan 430074China Henan Academy of Geology Zhengzhou 450052China

Nanofilms that can fast permeate solvents and accurately sieve molecules are of significant importance for separation.A promising strategy is to align the inner cavities of macrocycles into the channels within nanofilms,and control the channel size by selecting the ***,the channels outside the macrocycles are ***,we prepare nanofilms with hydrophobic channels(cyclodextrin inner cavity)and hydrophilic channels(cyclodextrin outer space)through interfacial polymerization of azobenzene-4,4’-dicarbonyl dichloride and amino-functionalizedβ-*** utilizing the significant geometric changes caused by the photoisomerization of azobenzene,nanofilms with adjustable hydrophilic channel sizes were *** nanofilms have high permeability to polar and non-polar solvents,and can distinguish molecules with almost the same molecular weight but different *** work expands the development of next-generation nanofilms generated through interfacial polymerization by incorporating rational molecular design.

关键词： nanofilm β-cyclodextrin azobenzene interfacial polymerization solvent permeation molecular sieving

Taiji-TianQin-LISA network:Precisely measuring the Hubble constant using both bright and dark sirens

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 59-77页

作者： Shang-Jie Jin Ye-Zhu zhang Ji-yu Song Jing-Fei zhang Xin zhang Key Laboratory of Cosmology and Astrophysics(Liaoning)&College of Sciences Northeastern UniversityShenyang 110819China Key Laboratory of Data Analytics and Optimization for Smart Industry(Ministry of Education) Northeastern UniversityShenyang 110819China National Frontiers Science Center for Industrial Intelligence and Systems Optimization Northeastern UniversityShenyang 110819China

In the coming decades,the space-based gravitational-wave(GW)detectors such as Taiji,TianQin,and LISA are expected to form a network capable of detecting millihertz GWs emitted by the mergers of massive black hole binaries(MBHBs).In this work,we investigate the potential of GW standard sirens from the Taiji-TianQin-LISA network in constraining cosmological *** the optimistic scenario in which electromagnetic(EM)counterparts can be detected,we predict the number of detectable bright sirens based on three different MBHB population models,i.e.,popⅢ,Q3d,and *** results show that the TaijiTianQin-LISA network alone could achieve a constraint precision of 0.9%for the Hubble constant,meeting the standard of precision ***,the Taiji-TianQin-LISA network could effectively break the cosmological parameter degeneracies generated by the CMB data,particularly in the dynamical dark energy *** combined with the CMB data,the joint CMB+Taiji-TianQin-LISA data offerσ(w)=0.036 in the wCDM model,which is close to the latest constraint result obtained from the CMB+SN *** also consider a conservative scenario in which EM counterparts are not *** to the precise sky localizations of MBHBs by the Taiji-TianQin-LISA network,the constraint precision of the Hubble constant is expected to reach 1.2%.In conclusion,the GW standard sirens from the Taiji-TianQin-LISA network will play a critical role in helping solve the Hubble tension and shedding light on the nature of dark energy.

关键词： space-based gravitational wave detection standard sirens the Taiji-TianQin-LISA network the Hubble constant dark energy

Rational design of ZnCdS/TpPa-1-COF heterostructure photocatalyst by strengthening the interface connection in solar hydrogen production reactions

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Nano Research 2024年第3期17卷 1027-1034页

作者： Di Yang Zhi-Gang Li Xinghao zhang Zenghuan Ren Weihan Lu Haining Liu Xiaomeng Guo Jijie zhang xian-He Bu Tianjin Key Laboratory of Metal and Molecule-Based Material Chemistry School of Materials Science and EngineeringNankai UniversityTianjin 300350China College of Chemistry and Pharmaceutical Engineering Hebei University of Science and TechnologyShijiazhuang 050018China State Key Laboratory of Elemento-Organic Chemistry College of ChemistryNankai UniversityTianjin 300071China

ZnCdS quantum dots(QDs)are highly coveted in photocatalysis research for their exceptional visible-light responses and high light-absorption ***,their practical application is hindered by their tendency to aggregate,due to having high surface *** address this issue,herein,a heterostructure is synthesized by growing ZnCdS QDs with a size of approximately 5 nm onto the surface of a two-dimensional(2D)covalent organic framework(COF),*** approach suppresses the aggregation of the QDs and improves their *** ZnCdS/TpPa-1-COF composite exhibited a peak hydrogen evolution rate of 6244.16μmol·g^(-1)·h^(-1),which was 2.89 and 4.18 times greater than that of ZnCdS and TpPa-1-COF,*** zero-dimensional/two-dimensional(0D/2D)heterojunction formed by ZnCdS and TpPa-1-COF generates a strong interfacial force,which is attributed to the intimate contact between the *** connections accelerate charge separation,improve the utilisation of reduced electrons,and reduce the extent of agglomeration of the ZnCdS QDs,thereby resulting in high hydrogen production activity of the ***,the photocatalytic mechanism is studied using Kelvin probe force microscopy and theoretical *** study offers a novel approach for creating sulfide photocatalysts and is crucial for investigating the potential practical applications of the related photocatalysts.

关键词： covalent organic frameworks quantum dots photocatalysis hydrogen generation heterojunction

Flexible regulation engineering of titanium nitride nanofibrous membranes for efficient electromagnetic microwave absorption in wide temperature spectrum

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Nano Research 2024年第3期17卷 1666-1675页

作者： Cuiping Li Lu zhang Shuai zhang Qiqi yu Dan Li Lei zhang Chunhong Gong Jingwei zhang Institute of Functional Polymer Composites College of Chemistry and Molecular SciencesHenan UniversityKaifeng 475004China National&Local Joint Engineering Research Center for Applied Technology of Hybrid Nanomaterials Henan UniversityKaifeng 475004China

Simultaneous development of well impedance matching and strong loss capability has become a mainstream method for achieving outstanding electromagnetic microwave absorption(EMWA)performances over wide temperature ***,it is difficult to pursue both due to the mutual restraint of relationship between impedance matching and loss capability about ***,we propose a flexible regulation engineering of titanium nitride(TiN)nanofibrous membranes(NMs,TNMs),which could be distributed uniformly in the polydimethylsiloxane(PDMS)matrix and contributed to the formation of abundant local conductive networks,generating the local conductive loss and enhancing the loss ability of ***,when the TNMs are used as functional units and dispersed in the matrix,the corresponding composites exhibit an outstanding anti-reflection effect on *** hoped,under the precondition of good impedance matching,local conductive loss and polarization loss together improve the loss capacity at room temperature,and polarization loss can compensate the local conductive loss to acquire effective dielectric response at elevated *** from the reasonably synergistic loss ability caused by flexible regulation engineering,the corresponding composites exhibit the perfect EMWA performances in a wide temperature range from 298 to 573 *** work not only elaborates the ponderable insights of independent membrane in the composition-structure-function connection,but also provides a feasible tactic for resolving coexistence of well impedance matching and strong loss capability issues in wide temperature spectrum.

关键词： flexible titanium nitride nanofibrous membranes local conductive loss dielectric loss electromagnetic microwave absorption wide temperature spectrum

Vanadium(V) Complexes Containing Unsymmetrical N-Heterocyclic Carbene Ligands: Highly Efficient Synthesis and Catalytic Behavior towards Ethylene/Propylene Copolymerization

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Chinese Journal of Polymer Science 2024年第1期42卷 32-41,I0006页

作者： Yi-Cong Wang Hui Zhat Pei-Yi Cheng Shu zhang xiang-Wei Liu Yi-xian Wu State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBejing 100029China

The highly efficient method has been developed for the synthesis of NHC·VOCl_(3) containing symmetrical or unsymmetrical Nheterocyclic carbene(NHC) ligands by the transmetallation reaction of NHC·AgCl with VOCl_(3).The total isolated yield of VOCl_(3)[1,3-(2,4,6-Me_(3)C_(6)H_(2))_(2)(NCH=)_(2)C:](V4') reached 86% by transmetallation reaction,which is much higher than that(48%) by direct coordination *** methodology has also been used to synthesize the novel vanadium complexes containing unsymmetrical NHC ligands of VOCl_(3)[PhCH_(2)NCH=CHNR)C:](V5',R=2,4,6-Me_(3)C_(6)H_(2);V6',R=2,4-Me_(2)-6-Ph-C_(6)H_(2);V7',R=2,6-^(i)Pr_(2)-C_(6)H_(3)) with high yield,which could not be obtained by direct coordination *** catalytic activity and copolymerization ability would be improved by introducing unsymmetrical NHC ligands due to their less steric bulky *** vanadium complex V5' containing unsymmetrical NHC ligand exhibits higher catalytic activity(3.7×10^(5)g_(copolymer)·mol^(-1) of V·h^(-1)) than that of V4' containing symmetrical NHC ***,the higher propylene incorporation ratio(45.6 mol%) in the copolymers of ethylene with propylene could be obtained by using V5' than that(39.9%) by using V4'.The results would provide a highly efficient strategy for the synthesis of early transition metal complexes containing versitile NHC ligands,affording the catalyst with both high catalytic activity and copolymerization ability for the synthesis of high performance polyolefin elastomers.

关键词： Vanadium complex N-heterocyclic carbene ligand Transmetallation reaction Copolymerization of ethylene with propylene

Investigation of multinucleon transfer processes in the Langevin equation model

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NUCLEAR SCIENCE AND TECHNIQUES 2024年第10期35卷 1-8页

作者： Zou, Ying zhang, Ming-Hao Wang, Mei-Chen zhang, yu-Hai zhang, Feng-Shou Beijing Normal Univ Sch Phys & Astron Key Lab Beam Technol Minist Educ Beijing 100875 Peoples R China Beijing Acad Sci & Technol Inst Radiat Technol Beijing 100875 Peoples R China Natl Lab Heavy Ion Accelerator Lanzhou Ctr Theoret Nucl Phys Lanzhou 730000 Peoples R China

Multinucleon transfer in low-energy heavy-ion collisions is increasingly considered a promising approach for generating exotic nuclei. Understanding the complex mechanisms involved in multinucleon transfer processes presents significant challenges for the theoretical investigation of nuclear reactions. A Langevin equation model was developed and employed to investigate multinucleon transfer processes. The 40Ar+232Th\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathrm{{40}Ar} + \mathrm{{232}Th}$$\end{document} reaction was simulated, and the calculated Wilczy & nacute;ski plot was used to verify the model. Additionally, to study the dynamics of multinucleon transfer reactions, the 136Xe+238U\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathrm{{136}Xe} + \mathrm{{238}U}$$\end{document} and 136Xe+209Bi\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathrm{{136}Xe} + \mathrm{{209}Bi}$$\end{document} reactions were simulated, and the corresponding TKE-mass and angular distributions were computed to analyze the energy dissipation and scattering angles. This investigation enhances our understanding of the dynamics involved in multinucleon transfer processes.

关键词： Reaction mechanisms Multinucleon transfer reactions Langevin equations Wilczy & nacute ski plot Exotic nuclei HEAVY-ION COLLISIONS QUASI-FISSION FUSION DYNAMICS DISSIPATION ISOTOPES NUCLEI ENERGY

Spherical Polyelectrolyte Brush Nanoreactor:Preparation of Hollow TiO_(2) Nanospheres and Characterization by Small Angle X-Ray Scattering

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Chinese Journal of Polymer Science 2024年第9期42卷 1393-1400,I0009页

作者： yu-Hua zhang Zi-yu zhang Xin Liu En-Guang Ma Jiang-Tao Guo Li Li Xu-Hong Guo State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai200237China Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology College of Chemistry and Chemical EngineeringDezhou UniversityDezhou253023China Institute of Bast Fiber Crops&Center of Southern Economic Crops Chinese Academy of Agricultural SciencesChangsha410205China

Titanium dioxide(TiO_(2))hollow nanoparticles present significant potential for photocatalytic applications while their straightforward preparation with precise structure control is still *** work reports the approach to preparing tunable hollow TiO_(2) nanospheres by utilization of spherical polyelectrolyte brushes(SPB)as nanoreactors and *** the preparation,the evolution of the structure was characterized by small angle X-ray scattering(SAXS),and in combination with dynamic light scattering and transmission electron *** formation of TiO_(2) shell within the brush(SPB@TiO_(2))is confirmed by the significant increase of the electron density,and its internal structure has been analyzed by fitting SAXS data,which can be influenced by Titanium precursors and ammonia *** calcining SPB@TiO_(2) in a muffle furnace,hollow TiO_(2) nanospheres are produced,and their transition to the anatase crystal form is triggered,as confirmed by X-ray diffraction *** the advantages of their hollow structure,these TiO_(2) nanospheres exhibit exceptional catalytic degradation efficiency of methylene blue(MB),tetracycline(TC),and 2,4-dichlorophenoxyacetic acid(2,4-D),and also demonstrate excellent recyclability.

关键词： Spherical polyelectrolyte brush Nanoreactor Hollow titanium dioxide X-ray scattering