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Parity-dependent skin effects and topological properties in the multilayer nonreciprocal su−Schrieffer−Heeger structures

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Frontiers of physics 2024年第3期19卷 115-133页

作者： Jia-Rui Li Cui Jiang Han su Di Qi Lian-Lian Zhang wei-Jiang Gong College of Sciences Northeastern UniversityShenyang 110819China Basic Department Shenyang Institute of EngineeringShenyang 110136China

We concentrate on the skin effects and topological properties in the multilayer non-Hermitian su−Schrieffer−Heeger (SSH) structure, by taking into account the nonreciprocal couplings between the different sublattices in the unit cells. Following the detailed demonstration of the theoretical method, we find that in this system, the skin effects and topological phase transitions induced by nonreciprocal couplings display the apparent parity effect, following the increase of the layer number of this SSH structure. On the one hand, the skin effect is determined by the parity of the layer number of this SSH system, as well as the parity of the band index of the bulk states. On the other hand, for the topological edge modes, such an interesting parity effect can also be observed clearly. Next, when the parameter disorders are taken into account, the zero-energy edge modes in the odd-layer structures tend to be more robust, whereas the other edge modes are easy to be destroyed. In view of these results, it can be ascertained that the findings in this work promote to understand the influences of nonreciprocal couplings on the skin effects and topological properties in the multilayer SSH lattices.

关键词： multilayer SSH lattice nonreciprocal couplings band structure skin effect

Effects of thinning on the understory light environment of different stands and the photosynthetic performance and growth of the reforestation species Phoebe bournei

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Journal of Forestry Research 2024年第1期35卷 12-28页

作者： Shicheng su Nianqing Jin Xiaoli wei College of Forestry Guizhou UniversityGuiyang 550025People’s Republic of China Institute for Forest Resources and Environment of Guizhou Guizhou UniversityGuiyang 550025People’s Republic of China

Light levels determine regeneration in stands and a key concern is how to regulate the light environment of different stand types to the requirements of the *** this study,we selected three stands typical in south China(a Cryptomeria japonica plantation,a Quercus acutissima plantation,and a mixed stand of both)and three thinning intensities to determine the best understory light environ-ment for 3-year-old Phoebe bournei *** canopy structure,understory light environment,and photosynthe-sis and growth indicators were assessed following *** improved canopy structure and understory light availability of each stand;species composition was the reason for differences in the understory light *** the same thinning intensity,the mixed stand had the greatest light radiation and most balanced spectral *** photosynthesis and growth were closely related to the light environment;all three stands required heavy thinning to create an effective and sustained understory light *** a suitable understory light environment,the efficiency of light interception,absorption,and use by seedlings was enhanced,resulting in a higher carbon assimilation the main limiting factor was stomatal *** a shade-avoidance signal,red/far-red radia-tion is a critical factor driving changes in photosynthesis and growth of *** seedlings,and a reduction increased light absorption and use capacity and height:diameter *** growth advantage transformed from diameter to height,enabling seedlings to access more *** findings suggest that the regeneration of shade-tolerant species such as *** could be enhanced if a targeted approach to thinning based on stand type was adopted.

关键词： Thinning Understory light environment Phoebe bournei Photosynthetic performance Growth performance

Effects of the number of neoadjuvant therapy cycles on clinical outcomes, safety, and survival in patients with metastatic colorectal cancer undergoing metastasectomy

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Oncology Research 2022年第2期30卷 65-76页

作者： YUNG-suNG YEH HSIANG-LIN TSAI YEN-CHENG CHEN wei-chih su PO-JUNG CHEN TsuNG-KUN CHANG CHING-CHUN LI CHING-WEN HUANG JAW-YUAN WANG Division of Trauma and surgical Critical Care Department of SurgeryKaohsiungMedical University HospitalKaohsiung Medical UniversityKaohsiungTaiwanChina Department of Emergency Medicine Faculty of Post-Baccalaureate MedicineCollege of MedicineKaohsiung Medical UniversityKaohsiungTaiwanChina Graduate Institute of Injury Prevention and Control College of Public HealthTaipei Medical UniversityTaipeiTaiwanChina Division of Colorectal surgery Department of SurgeryKaohsiung Medical University HospitalKaohsiung Medical UniversityKaohsiungTaiwanChina Department of surgery Faculty of MedicineCollege of MedicineKaohsiung Medical UniversityKaohsiungTaiwanChina Graduate Institute of Clinical Medicine College of MedicineKaohsiung Medical UniversityKaohsiungTaiwanChina Department of surgery Faculty of Post-Baccalaureate MedicineCollege of MedicineKaohsiung Medical UniversityKaohsiungTaiwanChina Graduate Institute of Medicine College of MedicineKaohsiung Medical UniversityKaohsiungTaiwanChina Center for Cancer Research Kaohsiung Medical UniversityKaohsiungTaiwanChina Pingtung Hospital Ministry of Health and WelfarePingtungTaiwanChina

The controversial outcomes in patients with metastatic colorectal cancer(mCRC)highlight the need for developing effective systemic neoadjuvant treatment strategies to improve clinical *** optimal treatment cycles in patients with mCRC for metastasectomy remain undeﬁ*** retrospective study compared the efﬁcacy,safety,and survival of cycles of neoadjuvant chemotherapy/targeted therapy for such ***-four patients with mCRC who received neoadjuvant chemotherapy/targeted therapy following metastasectomy were enrolled between January 2018 and April ***-eight patients received 6 cycles of chemotherapy/targeted therapy,whereas 36 patients received≥7 cycles(median,13;range,7–20).Clinical outcomes,including response,progression-free survival(PFS),overall survival(OS),and adverse events,were compared between these two *** the 64 patients,47(73.4%)were included in the response group,and 17(26.6%)were included in the nonresponse *** analysis revealed chemotherapy/targeted therapy cycle and pretreatment serum carcinoembryonic antigen(CEA)level as independent predictors of the response as well as overall survival and chemotherapy/targeted therapy cycle as an independent predictor of progression(all psults revealed shorter operation time,lower estimated operative blood loss,higher response rate,lower progression rate,and higher survival rate in≥7 cycles of chemotherapy/targeted therapy group(all p0.05).The median OS and PFS were 48 months(95%CI,40.855–55.145)and 28 months(95%CI,18.952–37.48)in the≥7-cycle group and 24 months(95%CI,22.038–25.962)and 13 months(95%CI,11.674–14.326)in the 6-cycle group,respectively(both p<0.001).The oncological outcomes in the≥7-cycle group were signiﬁcantly better than those in the 6-cycle group,without signiﬁcant increases in adverse ***,prospective randomized trials are mand

关键词： Metastatic colorectal cancer Neoadjuvant chemotherapy/targeted therapy Treatment cycles Metastasectomy

A Geometric Based Connection between Fractional Calculus and Fractal Functions

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Acta Mathematica Sinica,English Series 2024年第2期40卷 537-567页

作者： Yong Shun LIANG wei Yi su School of Mathematics and Statistic Nanjing University of Science and TechnologyNanjing 210094P.R.China Department of Mathematics Nanjing UniversityNanjing 210023P.R.China

Establishing the accurate relationship between fractional calculus and fractals is an important research content of fractional calculus *** the present paper,we investigate the relationship between fractional calculus and fractal functions,based only on fractal dimension *** dimension of the Riemann-Liouville fractional integral of continuous functions seems no more than fractal dimension of functions *** fractal dimension of the Riemann-Liouville fractional differential of continuous functions seems no less than fractal dimension of functions themselves when they *** further discussion,fractal dimension of the Riemann-Liouville fractional integral is at least linearly decreasing and fractal dimension of the Riemann-Liouville fractional differential is at most linearly increasing for the Holder continuous *** about other fractional calculus,such as the Weyl-Marchaud fractional derivative and the Weyl fractional integral has also been given *** work is helpful to reveal the mechanism of fractional calculus on continuous *** the same time,it provides some theoretical basis for the rationality of the definition of fractional *** is also helpful to reveal and explain the internal relationship between fractional calculus and fractals from the perspective of geometry.

关键词： Fractional calculus fractal functions fractal dimension fractional calculus equation relationship

A multi-agent collaboration scheme for energy-efficient task scheduling in a 3D UAV-MEC space

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Frontiers of Information Technology & Electronic Engineering 2024年第6期25卷 824-838页

作者： Yang LI Ziling wei Jinshu su Baokang ZHAO College of Computer National University of Defense TechnologyChangsha 410073China Academy of Military Sciences Beijing 100091China

Multi-access edge computing(MEC)presents computing services at the edge of networks to address the enormous processing requirements of intelligent *** to the maneuverability of unmanned aerial vehicles(UAVs),they can be used as temporal aerial edge nodes for providing edge services to ground users in ***,MEC environment is usually dynamic and *** is a challenge for multiple UAVs to select appropriate service ***,most of existing works study UAV-MEC with the assumption that the flight heights of UAVs are fixed;i.e.,the flying is considered to occur with reference to a two-dimensional plane,which neglects the importance of the *** this paper,with consideration of the co-channel interference,an optimization problem of energy efficiency is investigated to maximize the number of fulfilled tasks,where multiple UAVs in a threedimensional space collaboratively fulfill the task computation of ground *** the formulated problem,we try to obtain the optimal flight and sub-channel selection strategies for UAVs and schedule strategies for *** on the multi-agent deep deterministic policy gradient(MADDPG)algorithm,we propose a curiosity-driven and twin-networks-structured MADDPG(CTMADDPG)algorithm to solve the formulated *** uses the inner reward to facilitate the state exploration of agents,avoiding convergence at the sub-optimal ***,we adopt the twin critic networks for update stabilization to reduce the probability of Q value *** simulation results show that CTMADDPG is outstanding in maximizing the energy efficiency of the whole system and outperforms the other benchmarks.

关键词： Multi-access edge computing Multi-agent reinforcement learning Unmanned aerial vehicles Task scheduling

Water–solid contact electrification and catalysis adjusted by surface functional groups

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Nano Research 2024年第4期17卷 3344-3351页

作者： Yusen su Andy Berbille Zhong Lin Wang wei Tang CAS Center for Excellence in Nanoscience Beijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing100083China School of Nanoscience and Technology University of Chinese Academy of SciencesBeijing100049China Georgia Institute of Technology AtlantaGA 30332-0245USA

Chemical functional groups on solid surfaces greatly influence contact electrification(CE)at water–solid *** studies of their effects mainly swapped materials or bonded related molecules to a substrate,introducing other factors of *** work aims at unambiguously demonstrating the role of functional groups in water-polymer *** study the contribution of functional groups,by using ion coupled plasma etching to modify a high-density polyethylene(HDPE)film,a polymer with a naturally quasi-null charge transfer ***(HDPE–F)and hydroxyl(HDPE–OH)functional groups are generated and endowed HDPE with charge withdrawing ***–F withdraws 2.5–2.7 times more charges than HDPE–***,the surface charges accumulated generate electrostatic forces,altering the droplets *** phenomenon provides another approach to study CE,helping to evaluate the contribution of electrons to solid–liquid ***,employing HDPE–F to perform contact-electro-catalysis shows its activity is 2.4 times higher than that of commercial fluorinated films.

关键词： contact-electro-catalysis charge transfer solid–liquid interfaces contact electrification

superconducting,Topological,and Transport Properties of Kagome Metals CsTi_(3)Bi_(5)and RbTi_(3)Bi_(5)

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Research 2024年第2期2023卷 753-762页

作者： Xin-wei Yi Zheng-wei Liao Jing-Yang You Bo Gu Gang su School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Department of Physics Faculty of ScienceNational University of Singapore117551Singapore Kavli Institute for Theoretical Sciences and CAS Center for Excellence in Topological Quantum ComputationUniversity of Chinese Academy of SciencesBeijing 100190China

The recently discovered ATi_(3)Bi_(5)(A=Cs,Rb)exhibit intriguing quantum phenomena including superconductivity,electronic nematicity,and abundant topological ***_(3)Bi_(5)present promising platforms for studying kagome superconductivity,band topology,and charge orders in parallel with *** this work,we comprehensively analyze various properties of ATi_(3)Bi_(5)covering superconductivity under pressure and doping,band topology under pressure,thermal conductivity,heat capacity,electrical resistance,and spin Hall conductivity(SHC)using first-principles *** superconducting transition temperature(Tc)of CsTi_(3)Bi_(5)and RbTi_(3)Bi_(5)at ambient pressure are about 1.85 and 1.92 *** subject to pressure,Tc of CsTi_(3)Bi_(5)exhibits a special valley and dome shape,which arises from quasi-two-dimensional compression to three-dimensional isotropic compression within the context of an overall decreasing ***,Tc of RbTi_(3)Bi_(5)can be effectively enhanced up to 3.09 K by tuning the kagome van Hove singularities(VHSs)and flat band through *** can also induce abundant topological surface states at the Fermi energy(EF)and tune VHSs across ***,our transport calculations are in excellent agreement with recent experiments,confirming the absence of charge density ***,SHC of CsTi_(3)Bi_(5)can reach up to 226h·(e·Ω·cm)^(-1)at *** work provides a timely and detailed analysis of the rich physical properties for ATi_(3)Bi_(5),offering valuable insights for further experimental verifications and investigations in this field.

关键词： doping superconductivity conductivity

Critical Role of Ethylene-Propylene Block Copolymer in Impact Polypropylene Copolymer

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Chinese Journal of Polymer Science 2024年第3期42卷 344-351,I0007页

作者： Yu-Hui Tang Na Zhang wei Bao wei Jiang Yuan Lin Zhao-Hui su State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Ethylene-propylene block copolymer(EbP) is a vital component in impact polypropylene copolymer(IPC), yet its distribution in the multiphase composite material and how it influences the phase structure and the mechanical properties are not well understood. In this work,four IPCs were investigated by atomic force microscopy-infrared(AFM-IR) to assess the phase compositions in situ, based on which in conjunction with the chain microstructure information obtained ex situ the distributions of the copolymer components were derived for each alloy. For the IPCs whose EbP comprises long P and long E segments, the EbP fraction was found to phase separate from the rubber and the PP matrix to form the cores of the disperse particles with the E-P segmented copolymer(EsP). In contrast, in the IPC with EbP composed of long P and short E segments, the EbP fraction formed an outer shell for the rubber particles with the cores comprising the EsP alone, and this IPC, containing a lower E comonomer content than its counterpart, exhibited both better impact resistance and higher flexural modulus. These results clarify how the chain structure of EbP governs the phase morphology in IPC, which in turn impacts the properties of the composite material.

关键词： Impact polypropylene copolymers AFM-IR Ethylene-propylene block copolymers Core-shell rubber particles

Tungsten oxide/nitrogen-doped carbon nanotubes composite catalysts for enhanced redox kinetics in lithium-sulfur batteries

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Chinese Journal of Chemical Engineering 2024年第3期67卷 58-67页

作者： Deqing He Zihao Xie Qian Yang wei Wang Chao su School of Energy and Power Jiangsu University of Science and TechnologyZhenjiang 212100China State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing 211816China

The sluggish redox kinetics of polysulfides in lithium-sulfur(Li-S)batteries are a significant obstacle to their widespread adoption as energy storage ***,recent studies have shown that tungsten oxide(WO_(3))can facilitate the conversion kinetics of polysulfides in Li-S ***,we fabricated host materials for sulfur using nitrogen-doped carbon nanotubes(N-CNTs)and WO_(3).We used low-cost components and simple procedures to overcome the poor electrical conductivity that is a disadvantage of metal *** composites of WO_(3) and N-CNTs(WO_(3)/N-CNTs)create a stable framework structure,fast ion diffusion channels,and a 3D electron transport network during electrochemical reaction *** a result,the WO_(3)/N-CNT-Li2S6 cathode demonstrates high initial capacity(1162 mA·h·g^(-1) at 0.5℃),excellent rate performance(618 mA·h·g^(-1) at 5.5℃),and a low capacity decay rate(0.093%up to 600 cycles at 2℃).This work presents a novel approach for preparing tungsten oxide/carbon composite catalysts that facilitate the redox kinetics of polysulfide conversion.

关键词： Li-S batteries Composites Ion diffusion channels 3D electron transport network Redox kinetics