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Universal paradigm of ternary metacomposites with tunable epsilon-negative and epsilon-near-zero response for perfect electromagnetic shielding

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Rare Metals 2024年第2期43卷 796-809页

作者： Yun-peng Qu Yun-Lei Zhou Yang Luo Yao Liu Jun-Fei Ding Yan-Li Chen Xiu Gong Jing-Liang Yang qiong peng Xiao-Si Qi College of Physics Guizhou UniversityGuiyang550025China Hangzhou Institute of Technology Xidian UniversityHangzhou311231China Department of Materials ETH Zurich8093ZurichSwitzerland Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials(Ministry of Education) Shandong UniversityJinan250061China

CaCu_(3)Ti_(4)O_(12)(CCTO)ceramic nanocomposites incorporating graphene–carbon black(GRCB)fillers were fabricated by spark plasma sintering process.The percolative effects of conductive GRCB fillers on dielectric response of GRCB/CCTO ternary metacomposites were systematically investigated.The weakly real permittivity(ε′)-negative response(ε′~−1×10^(2))was achieved which originated from weakly low-frequency plasmonic state of free carriers within constructed GRCB networks.With enhancing three-dimensional GRCB network,the plasma frequency of metacomposites increased while the damping factor decreased.Herein,theε′-negative values of metacomposites were tuned from−10^(2) to−10^(4) orders of magnitude andε′-near-zero(ENZ)frequencies from~142 to~340 MHz which substantially benefited from the moderate carrier concentration of GRCB dual fillers.The Drude model and equivalent circuit models were adopted to demonstrate dielectric and electrical characteristics.The obtained metacomposites show strong EM shielding effect along with enhanced plasmonic oscillation and even better achieving perfect EM shielding effect in ENZ media.This work achieves the tunableε′-negative andε′-near-zero response and more importantly clarifies its regulation mechanism in ceramic-based ternary metacomposites,which opens up the possibility of designing high-performance EM shielding materials based on metacomposites.

关键词： Metacomposites Ceramic matrix composites Negative permittivity Epsilon-near-zero Electromagnetic shielding

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Multifunctional cellular carbon foams derived from chitosan toward self-cleaning, thermal insulation, and highly efficient microwave absorption properties

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Nano Research 2024年第3期17卷 927-938页

作者： Beibei Zhan Yanling Hao Xiaosi Qi Yunpeng Qu Junfei Ding Jing-liang Yang Xiu Gong Yanli Chen qiong peng Wei Zhong College of Physics Guizhou Province Key Laboratory for Photoelectrics Technology and ApplicationGuizhou UniversityGuiyang 550025China Minzu Normal University of Xingyi Xingyi 562400China National Laboratory of Solid State Microstructures and Jiangsu Provincial Laboratory for NanoTechnology Nanjing UniversityNanjing 210093China

To adapt the practical demand,designing and constructing the multifunctional microwave absorbers(MAs)is the key future direction of research and development.However,effective integrating the multiple functions into a single material remains a huge challenge.Herein,cellular carbon foams(CCFs)with different porous structures were elaborately designed and fabricated in high efficiency through a facile continuous freeze-drying and carbonization processes using a sustainable biomass chitosan as the precursor.The obtained results revealed that the thermal treated temperature and g-C_(3)N_(4) amount played a great impact on the carbonization degrees,pore sizes,and morphologies of CCFs,which led to their tunable electromagnetic(EM)parameters,improved conduction loss,and polarization loss abilities.Owing to the special cellular structure,the designed CCFs samples simultaneously displayed the strong absorption capabilities,broad absorption bandwidths,and thin matching thicknesses.Meanwhile,the as-prepared CCFs exhibited the strong hydrophobicity and good thermal insulation,endowing its attractive functions of self-cleaning and thermal insulation.Therefore,our findings not only presented a facile approach to produce different porous structures of CCFs,but also provided an effective strategy to develop multifunctional high-performance MAs on basis of three-dimensional CCFs.

关键词： multifunctional microwave absorbers carbon foams cellular structure self-cleaning thermal insulation

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Analysis of the Correlation Between Visceral Fat Area and Insulin Resistance in Patients with Type 2 Diabetes and Abdominal Obesity

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Journal of Clinical and Nursing Research 2024年第4期8卷 243-247页

作者： Guohui Zhang Juan Xu qiong peng Yalei Xu Shaochang Ma Guandu People’s Hospital of Kunming Kunming 650200China

Objective: To analyze the correlation between visceral fat area and insulin resistance index (HOMA-IR) in patients with type 2 diabetes mellitus (T2DM) and abdominal obesity and to provide a reference for screening and related research of such patients. Methods: Two hundred patients with T2DM admitted to Guandu People’s Hospital of Kunming were included. The study was carried out from October 2022 to December 2023. The patients were divided into three groups according to different abdominal visceral fat areas (VFA): Group A (n = 65) was less than 75cm2, Group B (n = 75) was 75-100 cm2, and Group C (n = 60) was greater than 100 cm2. The subjects in the three groups were all tested for glycated hemoglobin (HbA1c), fasting insulin (FINS), and fasting blood glucose (FPG). Height and weight were measured to calculate body mass index (BMI). The HOMA-IR and TYG (fasting triglyceride and glycemic index) were also calculated. Changes in the BMI, VFA, HOMA-IR, and TYG levels were observed in the three groups. Results: The VFA, BMI, HbA1c, FPG, FINS, HOMA-IR, and TYG of the patients all increased, with a more significant increase in the BMI, FINS, HOMA-IR, and TYG levels (P < 0.01). Multiple linear stepwise regression analyses used visceral fat area (VFA) as the dependent variable. The results showed that VFA was closely related to BMI, FINS, HOMA-IR, and TYG. Conclusion: Early reduction of VFA to reduce insulin resistance may be a better treatment and effective method for T2DM, providing powerful measures and new strategies for effective blood sugar control and early prevention in the treatment of metabolic diseases.

关键词： Type 2 diabetes Abdominal obesity Visceral fat area Insulin resistance

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Enhanced and asymmetric signatures of hybridization at climatic margins: Evidence from closely related dioecious fig species

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Plant Diversity 2024年第2期46卷 181-193页

作者： Jian-Feng Huang Clive T.Darwell Yan-qiong peng CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla 666303China National Center for Genetic Engineering and Biotechnology(BIOTEC) 113 Thailand Science ParkPhahonyothin RoadKhlong NuengKhlong LuangPathum Thani 12120Thailand

Hybridization plays a significant role in biological evolution. However, it is not clear whether ecological contingency differentially influences likelihood of hybridization, particularly at ecological margins where parental species may exhibit reduced fitnesses. Moreover, it is unknown whether future ecosystem change will increase the prevalence of hybridization. Ficus heterostyla and F. squamosa are closely related species co-distributed from southern Thailand to southwest China where hybridization, yielding viable seeds, has been documented. As a robust test of ecological factors driving hybridization, we investigated spatial hybridization signatures based on nuclear microsatellites from extensive population sampling across a widespread contact range. Both species showed high population differentiation and strong patterns of isolation by distance. Admixture estimates exposed asymmetric interspecific gene flow.Signatures of hybridization increase significantly towards higher latitude zones, peaking at the northern climatic margins. Geographic variation in reproductive phenology combined with ecologically challenging marginal habitats may promote this phenomenon. Our work is a first systematic evaluation of such patterns in a comprehensive, latitudinally-based clinal context, and indicates that tendency to hybridize appears strongly influenced by environmental conditions. Moreover, that future climate change scenarios will likely alter and possibly augment cases of hybridization at ecosystem scales.

关键词： Hybridization Heterospecific visitation Fig Pollinator wasp Asymmetric gene flow

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Population size estimates based on GPS telemetry

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Zoological Research 2024年第1期45卷 36-38页

作者： Yu-Xuan Fan Pu-Zheng Xie Chi Ma Ting Chen Xiao Ye Hua-Lin Xu qiong Yang peng-Fei Fan School of Life Sciences Sun Yat-sen UniversityGuangzhouGuangdong 510275China College of Agriculture and Biological Sciences DaliYunnan 671003China Neilingding-Futian National Nature Reserve of Guangdong ShenzhenGuangdong 518040China

DEAR EDITOR,Accurate estimation of population size is a crucial issue in wildlife population ecology and conservation.While Global Positioning System(GPS)collars are well recognized as an effective method for monitoring wildlife behavior,their application in direct wildlife population size estimation remains underutilized.In this study,GPS telemetry was employed to survey a rhesus macaque(Macaca mulatta)population on Neilingding Island in Guangdong,China.From May 2021 to April 2022,32 macaques across nine groups were fitted with GPS collars,producing a dataset of 109739 location fixes.Analyzing data from all tracked individuals revealed the annual home ranges of the nine groups.

关键词： China Island size

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Establishment of human cerebral organoid systems to model early neural development and assess the central neurotoxicity of environmental toxins

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Neural Regeneration Research 2025年第1期20卷 242-252页

作者： Daiyu Hu Yuanqing Cao Chenglin Cai Guangming Wang Min Zhou Luying peng Yantao Fan qiong Lai Zhengliang Gao Fundamental Research Center Shanghai Yangzhi Rehabilitation Hospital(Shanghai Sunshine Rehabilitation Center)School of MedicineTongji UniversityShanghaiChina Institute of Geriatrics(Shanghai University) Affiliated Nantong Hospital of Shanghai University(The Sixth People’s Hospital of Nantong)Shanghai University School of MedicineNantongJiangsu ProvinceChina Shanghai Engineering Research Center of Organ Repair Shanghai University School of MedicineShanghaiChina Key Laboratory of Arrhythmias Ministry of EducationShanghai East HospitalSchool of MedicineTongji UniversityShanghaiChina

Human brain development is a complex process,and animal models often have significant limitations.To address this,researchers have developed pluripotent stem cell-derived three-dimensional structures,known as brain-like organoids,to more accurately model early human brain development and disease.To enable more consistent and intuitive reproduction of early brain development,in this study,we incorporated forebrain organoid culture technology into the traditional unguided method of brain organoid culture.This involved embedding organoids in matrigel for only 7 days during the rapid expansion phase of the neural epithelium and then removing them from the matrigel for further cultivation,resulting in a new type of human brain organoid system.This cerebral organoid system replicated the temporospatial characteristics of early human brain development,including neuroepithelium derivation,neural progenitor cell production and maintenance,neuron differentiation and migration,and cortical layer patterning and formation,providing more consistent and reproducible organoids for developmental modeling and toxicology testing.As a proof of concept,we applied the heavy metal cadmium to this newly improved organoid system to test whether it could be used to evaluate the neurotoxicity of environmental toxins.Brain organoids exposed to cadmium for 7 or 14 days manifested severe damage and abnormalities in their neurodevelopmental patterns,including bursts of cortical cell death and premature differentiation.Cadmium exposure caused progressive depletion of neural progenitor cells and loss of organoid integrity,accompanied by compensatory cell proliferation at ectopic locations.The convenience,flexibility,and controllability of this newly developed organoid platform make it a powerful and affordable alternative to animal models for use in neurodevelopmental,neurological,and neurotoxicological studies.

关键词： cadmium cell death cell proliferation cortical development environmental toxins neural progenitor cells neurogenesis neurotoxicology organoids stem cells

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Tunable and improved microwave absorption of flower-like core@shell MFe_(2)O_(4)@MoS_(2)(M=Mn,Ni and Zn)nanocomposites by defect and interface engineering

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Journal of Materials Science & Technology 2023年第8期139卷 137-146页

作者： Junxiong Xiao Xiaosi Qi Xiu Gong qiong peng Yanli Chen Ren Xie Wei Zhong College of Physics Guizhou Province Key Laboratory for Photoelectrics Technology and ApplicationGuizhou UniversityGuiyang 550025China National Laboratory of Solid State Microstructures and Jiangsu Provincial Laboratory for NanoTechnology Nanjing UniversityNanjing 210093China

Previous results revealed that the defect and/or interface had a great impact on the electromagnetic pa-rameters of materials.In order to understand the main physical mechanisms and effectively utilize these strategies,in this study,M Fe_(2)O_(4)and flower-like core@shell M Fe_(2)O_(4)@MoS_(2)(M=Mn,Ni,and Zn)sam-ples with different categories were elaborately designed and selectively produced in large scale through a simple two-step hydrothermal reaction.We conducted the systematical investigation on their microstruc-tures,electromagnetic parameters and microwave absorption performances(MAPs).The obtained results revealed that the large radius of M^(2+)cation could effectively boost the concentration of oxygen vacancy in the M Fe_(2)O_(4)and M Fe_(2)O_(4)@MoS_(2)samples,which resulted in the improvement of dielectric loss capabil-ities and MAPs.Furthermore,the introduction of MoS_(2)nanosheets greatly improved the interfacial effect and enhanced the polarization loss capabilities,which also boosted the MAPs.By taking full advantage of the defect and interface,the designed M Fe_(2)O_(4)@MoS_(2)samples displayed tunable and excellent com-prehensive MAPs including strong absorption capability,wide absorption bandwidth and thin matching thicknesses.Therefore,the clear understanding of defect and interface engineering made these strategies well elaborately designed and applicable to improving MAPs.

关键词： Core@shell structure M Fe_(2)O_(4)@MoS_(2)(M=Mn,Ni and Zn) Defect and interface engineering Improved microwave absorption properties

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Defect and interface engineering in core@shell structure hollow carbon@MoS_(2)nanocomposites for boosted microwave absorption performance

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Nano Research 2022年第9期15卷 7778-7787页

Defect and interface engineering are efficient approaches to adjust the physical and chemical properties of nanomaterials.In order to effectively utilize these strategies for the improvement of microwave absorption properties(MAPs),in this study,we reported the synthesis of hollow carbon shells and hollow carbon@MoS_(2)nanocomposites by the template-etching and templateetching-hydrothermal methods,respectively.The obtained results indicated that the degree of defect for hollow carbon shells and hollow carbon@MoS_(2)could be modulated by the thickness of hollow carbon shell,which effectively fulfilled the optimization of electromagnetic parameters and improvement of MAPs.Furthermore,the microstructure investigations revealed that the precursor of hollow carbon shells was encapsulated by the sheet-like MoS_(2)in high efficiency.And the introduction of MoS_(2)nanosheets acting as the shell effectively improved the interfacial effects and boosted the polarization loss capabilities,which resulted in the improvement of comprehensive MAPs.The elaborately designed hollow carbon@MoS_(2)samples displayed very outstanding MAPs including strong absorption capabilities,broad absorption bandwidth,and thin matching thicknesses.Therefore,this work provided a viable strategy to improve the MAPs of microwave absorbers by taking full advantage of their defect and interface engineering.

关键词： core@shell structure hollow carbon shells hollow carbon@MoS_(2) defect and interface engineering improved microwave absorption properties

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Magnetic-dielectric synergy and interfacial engineering to design yolk-shell structured CoNi@void@C and CoNi@void@C@MoS_(2) nanocomposites with tunable and strong wideband microwave absorption

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Nano Research 2022年第7期15卷 6761-6771页

作者： Chen Li Xiaosi Qi Xiu Gong qiong peng Yanli Chen Ren Xie Wei Zhong College of Physics Guizhou Province Key Laboratory for Photoelectrics Technology and ApplicationGuizhou UniversityGuiyang 550025China National Laboratory of Solid State Microstructures and Jiangsu Provincial Laboratory for NanoTechnology Nanjing UniversityNanjing 210093China

In order to effectively utilize the magnetic-dielectric synergy and interfacial engineering,in this paper,yolk–shell structured magnetic multicomponent nanocomposites(MCNCs)including CoNi@void@C and CoNi@void@C@MoS_(2) were produced in large scale by in-situ pyrolysis of cubic CoNi Prussian blue analogs(PBAs)followed by the hydrothermal process,respectively.Because of their unique structures,excellent synergistic effect between dielectric and magnetic loss,the as-prepared CoNi@void@C and CoNi@void@C@MoS_(2) MCNCs displayed very outstanding electromagnetic wave absorption performances(EMWAPs)including strong absorption capabilities,broad absorption bandwidth and thin matching thicknesses.Furthermore,the as-prepared CoNi@void@C and CoNi@void@C@MoS_(2) MCNCs well maintained the cubic configuration of CoNi PBAs even after the thermal treatment and hydrothermal processes.The unique structure and formed carbon layers effectively prevented the corrosion of internal CoNi alloy during the formation of MoS_(2),and CoNi@void@C@MoS_(2) MCNCs with different MoS_(2) contents could be synthesized by controlling the hydrothermal temperature.The obtained results revealed that the EM parameters,dielectric and magnetic loss capabilities of CoNi@void@C@MoS_(2) MCNCs could be tuned by controlling hydrothermal temperature and filler loading,which made their outstanding EMWAPs could be achieved in different frequency regions.Taking account of simple process,low density and high chemical stability,our findings provided a new and effective pathway to develop the strong wideband microwave absorbers.

关键词： yolk-shell structure CoNi@void@C CoNi@void@C@MoS_(2) interface polarization strong wideband microwave absorbers

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Microstructure optimization of core@shell structured MSe_(2)/FeSe_(2)@MoSe_(2)(M=Co,Ni)flower-like multicomponent nanocomposites towards high-efficiency microwave absorption

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Journal of Materials Science & Technology 2022年第33期128卷 59-70页

作者： Jingjing Zhang Xiaosi Qi Xiu Gong qiong peng Yanli Chen Ren Xie Wei Zhong College of Physics Guizhou Province Key Laboratory for Photoelectrics Technology and ApplicationGuizhou UniversityGuiyang 550025China National Laboratory of Solid State Microstructures and Jiangsu Provincial Laboratory for NanoTechnology Nanjing UniversityNanjing 210093China

In this work,we put forward a scheme to exquisitely design and selectively synthesize the core@shell structured MSe_(2)/FeSe_(2)@MoSe_(2)(M=Co,Ni)flower-like multicomponent nanocomposites(MCNCs)through a simple two-step hydrothermal reaction on the surfaces of MFe_(2)O_4 nanospheres with the certain amounts of Mo and Se sources.With increasing the amounts of Mo and Se sources,the obtained core@shell structured MSe_(2)/FeSe_(2)@MoSe_(2)(M=Co,Ni)MCNCs with the enhanced content of MoSe_(2)and improved flower-like geometry morphology could be produced on a large scale.The obtained results revealed that the as-prepared samples displayed improved comprehensive microwave absorption properties(CMAPs)with the increased amounts of Mo and Se sources.The as-prepared CoSe_(2)/FeSe_(2)@MoSe_(2)and NiSe_(2)/FeSe_(2)@MoSe_(2)MCNCs with the well-defined flower-like morphology could simultaneously present the outstanding CMAPs in terms of strong absorption capability,wide absorption bandwidth,and thin matching thicknesses,which mainly originated from the conduction loss and flower-like geometry morphology.Therefore,the findings not only develop the very desirable candidates for high-performance microwave absorption materials but also pave a new way for optimizing the CMAPs through tailoring morphology engineering.

关键词： Core@shell structure MSe_(2)/FeSe_(2)@MoSe_(2)(M=Co.Ni) multicomponent nanocomposites Flower-like geometry morphology Broad frequency bandwidth Microwave absorption

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