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Metasurface-assisted low-frequency performance enhancement of ultra-broadband honeycomb absorber based on carbon nanotubes

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Nano Research 2024年第9期17卷 8542-8551页

作者： Cai-Liang Wang Shuang Bai Pei-Yan Zhao Tao Zhou Hui-Ya Wang Jun-Peng Wang Luo-Xin Wang guang-sheng Wang School of Chemistry Beihang UniversityBeijing 100191China Aerospace Science and Industry Corporation of Wuhan Magnetoelectricity Co. Ltd.Wuhan 430070China College of Materials Science and Engineering Key Laboratory for New Textile Materials and Applications of Hubei ProvinceWuhan Textile UniversityWuhan 430200China School of Chemistry and Chemical Engineering Lingnan Normal UniversityZhanjiang 524048China School of Materials Science and Engineering Zhejiang Sci-Tech UniversityHangzhou 310018China

Here,we.present a unique method to enhance the low-frequency absorption performance of a honeycomb absorber by integrating a *** geometrical dimensions of the proposed metasurface have been numerically *** introduction of the metasurface allows exploitation of its robust resonance and superior impedance matching in low-frequency bands,thereby improving microwave absorption *** incorporation of the metasurface does not impact the wave transmission performance of the honeycomb core absorber at high-frequency band,thus preserving its high-frequency *** broadens the absorption range,leading to an expanded *** results reveal that the composite absorber(CA)exhibits strong absorption performance with an incident angle stability up to 45°for both transverse electric(TE)and transverse magnetic(TM)*** absorption mechanism of the CA has been investigated by using an equivalent circuit model and electromagnetic field analysis.A prototype was designed,fabricated,and tested to validate the proposed *** simulation and measurement results demonstrate that the prototype can achieve an average absorption rate exceeding 90%across a 1.0-18.0 GHz *** study introduces an innovative technique for creating microwave absorbers for low-frequency wideband applications.

关键词： low frequency metasurface radar absorption impedance matching

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Full waveform inversion based on hybrid gradient

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Petroleum Science 2024年第3期21卷 1660-1670页

作者： Chuang Xie Zhi-Liang Qin Jian-Hua Wang Peng Song Heng-guang Shen sheng-Qi Yu Ben-Jun Ma Xue-Qin Liu Qingdao Innovation and Development Base Harbin Engineering UniversityQingdao266000ShandongChina Qingdao Innovation and Development Center Harbin Engineering UniversityQingdao266000ShandongChina CNOOC Research Institute Co. Ltd.Beijing100028China College of Marine Geoscience Ocean University of ChinaQingdao266100ShandongChina we.hai Sunfull Geophysical Exploration Equipment Co. Ltd.Weihai264209ShandongChina

The low-wavenumber components in the gradient of full waveform inversion(FWI)play a vital role in the stability of the ***,when FWI is implemented in some high frequencies and current models are not far away from the real velocity model,an excessive number of low-wavenumber components in the gradient will also reduce the convergence rate and inversion *** solve this problem,this paper firstly derives a formula of scattering angle we.ghted gradient in FWI,then proposes a hybrid *** hybrid gradient combines the conventional gradient of FWI with the scattering angle we.ghted gradient in each inversion frequency band based on an empirical formula derived *** we.ghted hybrid mode,we.can retain some low-wavenumber components in the initial lowfrequency inversion to ensure the stability of the inversion,and use more high-wavenumber components in the high-frequency inversion to improve the convergence *** results of synthetic data experiment demonstrate that compared to the conventional FWI,the FWI based on the proposed hybrid gradient can effectively reduce the low-wavenumber components in the gradient under the premise of ensuring inversion *** also greatly enhances the convergence rate and inversion accuracy,especially in the deep part of the *** the field marine seismic data experiment also illustrates that the FWI based on hybrid gradient(HGFWI)has good stability and adaptability.

关键词： Full waveform inversion Hybrid gradient Scattering angle we.ghted Low-wavenumber component

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Development of a clinical nomogram for prediction of response to neoadjuvant chemotherapy in patients with advanced gastric cancer

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World Journal of Gastrointestinal Surgery 2024年第2期16卷 396-408页

作者： Bing Liu Yu-Jie Xu Feng-Ran Chu guang Sun Guo-Dong Zhao sheng-Zhong Wang Department of Gastrointestinal Surgery Central South University Xiangya School of Medicine Affiliated Haikou HospitalHaikou 570208Hainan ProvinceChina Clinical College Hainan Medical UniversityHaikou 571199Hainan ProvinceChina

BACKGROUND The efficacy of neoadjuvant chemotherapy(NAC)in advanced gastric cancer(GC)is still a controversial *** To find factors associated with chemosensitivity to NAC treatment and to provide the optimal therapeutic strategies for GC patients receiving *** The clinical information was collected from 230 GC patients who received NAC treatment at the Central South University Xiangya School of Medicine Affiliated Haikou Hospital from January 2016 to December *** absolute shrinkage and selection operator logistic regression analysis was used to find the possible predictors.A nomogram model was employed to predict the response to *** In total 230 patients we.e finally included in this study,including 154 males(67.0%)and 76 females(33.0%).The mean age was(59.37±10.60)years,ranging from 24 years to 80 *** to the tumor regression grade standard,there we.e 95 cases in the obvious response group(grade 0 or grade 1)and 135 cases in the poor response group(grade 2 or grade 3).The obvious response rate was 41.3%.Least absolute shrinkage and selection operator analysis showe. that four risk factors significantly related to the efficacy of NAC we.e tumor location(Pwe. that the nomogram had a good value in clinical *** A nomogram combining tumor location,histological differentiation,clinical T stage,and carbohydrate antigen 724 showe. satisfactory predictive powe. to the response of NAC and can be used by gastrointestinal surgeons to determine the optimal treatment strategies for advanced GC patients.

关键词： Advanced gastric cancer Predictor Neoadjuvant chemotherapy Nomogram Tumor regression grade

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Investigation of the cell composition and gene expression in the delayed-type hypersensitivity tuberculin skin test

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Military Medical Research 2024年第1期11卷 148-151页

作者： Hui-Juan Duan Hong-Qian Chu Ting-Ming Cao guang-Ming Dai Na Tian Gang sheng Zhao-Gang Sun Beijing Key Laboratory in Drug Resistant Tuberculosis Research Beijing Tuberculosis and Thoracic Tumor Research InstituteBeijing Chest HospitalCapital Medical UniversityBeijing 101149China

Dear Editor,The tuberculin skin test(TST)reagents have continuously improved,with the ESAT6-CFP10(EC)test having recently been introduced,but are seldom based on the direction of the delayed-type hypersensitivity(DTH)*** studies only partially showe. the infiltration and activation of immune cells and the production of cytokines of the skin induration[1,2],and lack the detailed measurements of cell proportions and gene expression in the DTH ***,in this study,we.revealed the comprehensive characteristics of DTH by single-cell RNA sequencing(scRNA-seq)in the guinea pig tuberculosis(TB)model[Experimental Animal we.fare Ethics Committee,Beijing Tuberculosis and Thoracic Tumor Research Institute(2021-064)].

关键词： Tuberculin skin test Delayed-type hypersensitivity Single-cell RNA sequencing

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A review on WO_(3)-based composite photocatalysts:synthesis,catalytic mechanism and diversified applications

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Rare Metals 2024年第8期43卷 3441-3459页

作者： Xue Zhang Zi-Qi Zhang Yan-Dong Sun Xiao-Jia Ma Feng-Xian Jin Fang-Yuan Zhang we.-guang Han Bo-Xiong Shen sheng-Qi Guo College of Energy and Environmental Engineering Hebei University of TechnologyTianjin 300401China Department of Food and Chemical Engineering Liuzhou Institute of TechnologyLiuzhou 545616China

Photocatalysis as an emerging "green" energy conversion technology has attracted domestic and international *** technology uses semiconductor photocatalysts to convert solar energy into directly usable chemical energy,showing great potential for application in environmental pollutant purification and clean energy production,with broad development *** many semiconductor materials,tungsten trioxide(WO_(3)) is favored by researchers in the field of photocatalysis because of its good visible light response and excellent valence band hole oxidation ***,a large number of photocatalysts based on WO_(3),in particular W03-based composite photocatalysts,have been reported,and their applications cover a wide range of *** order to promote the development of WO_(3)-based photocatalysts and provide a reference for colleagues,we.present a systematic summary of the applications and research progress of W03-based composites in the field of photocatalysis in recent *** from the structural properties of WO_(3)itself,this article summarizes the preparation methods and structure-activity relationships of WO_(3)-based composite ***,it introduces the current application status of existing WO_(3)-based composite photocatalysts in CO_(2) reduction,hydrogen production,nitrogen fixation,and pollutant ***,the development prospects we.e analyzed.

关键词： WO_(3)-based composite photocatalysts Intrinsic characteristic Preparation method Reaction mechanism Applications

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Interaction mechanism betwe.n BaZrO_(3)/Y_(2)O_(3) refractory and Ti_(2)Ni alloy melts

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Journal of Iron and Steel Research(International) 2024年第6期31卷 1376-1388页

作者： Xiao Hou guang-yao Chen Jian Liu Ming-rui Lv Fei-hai Yu Qi-sheng Feng Rong-bin Li Xiong-gang Lu Chong-he Li State Key Laboratory of Advanced Special Steel and Shanghai Key Laboratory of Advanced Ferromeallurgy and School of Materials Science and Engineering Shanghai UniversityShanghai 200072China Shanghai Special Casting Engineering Technology Research Center Shanghai 201605China Zhejiang Institute of Advanced Materials Shanghai UniversityJiashan 314100ZhejiangChina School of Materials Science and Engineering Shanghai DianJi UniversityShanghai 201306China

The titanium alloys with highly chemical activity require stable crucible refractories that can withstand the erosion of alloy *** phase composition and microstructure are crucial factors that affect the stability of the refractory *** effect of Y_(2)O_(3) on the composition and microstructure of BaZrO_(3) crucible was systematically investigated,and the improved mechanism of the stability of BaZrO_(3)/Y_(2)O_(3) crucible was clarified in comparison with the BaZrO_(3) *** results showe. that the erosion layer thickness of the BaZrO_(3)/Y_(2)O_(3) crucible was only 63μm,which was far less than that in the BaZrO_(3) crucible(485μm),and the erosion layer in the BaZrO_(3)/Y_(2)O_(3) crucible also exhibited a higher density than that in the BaZrO_(3) *** the sintering,Y_(2)O_(3) could improve the densification of the BaZrO_(3) crucible due to the solid solution effect betwe.n Y_(2)O_(3) and ZrO_(2),which also caused the evaporation of BaO,resulting in the generation of a Y_(2)O_(3)(ZrO_(2))film on the surface of the ***,the Y_(2)O_(3)(ZrO_(2))had higher thermodynamic stability than Y_(2)O_(3),confirming that the BaZrO_(3)/Y_(2)O_(3) crucible with high density exhibited a superior erosion resistance to titanium *** dual-phase structure provides a strategy to design a long-life and stable refractory for melting titanium alloys.

关键词： Barium zirconate Yttrium oxide Dual-phase refractory Titanium alloy Interaction

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Dynamic foraging strategy adaptation to heterogeneous environments contributes to social aggregation in snub-nosed monkeys

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Zoological Research 2024年第1期45卷 39-54页

作者： Lan Zhao sheng-Nan Ji Xiao-Bing Du Jia-Hui Liu Bo-Lun Zhang Pei-Hua Li Yi-Jun Yang Bao-Guo Li Yan-Qing Guo Xiao-guang Qi College of Life Sciences Northwest UniversityXi’anShaanxi 710069China Chengdu Institute of Biology Chinese Academy of SciencesChengduSichuan 610041China State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China

The dynamics of animal social structures are heavily influenced by environmental patterns of competition and *** folivorous colobine primates,prevailing theories suggest that larger group sizes should be favored in rainforests with a year-round abundance of food,thereby reducing feeding ***,paradoxically,larger groups are frequently found in high-altitude or high-latitude montane ecosystems characterized by a seasonal scarcity of *** contradiction is posited to arise from cooperative benefits in heterogeneous *** investigate this hypothesis,we.carried out a six-year field study on two neighboring groups of golden snub-nosed monkey(Rhinopithecus roxellana),a species representing the northernmost distribution of colobine *** showe. that the groups adjusted their movement and habitat selection in response to fluctuating climates and spatiotemporal variability of resources,indicative of a dynamic foraging ***,during the cold,resource-scarce conditions in winter,the large group occupied food-rich habitats but did not exhibit significantly longer daily travel distances than the smaller neighboring ***,we.compiled an eco-behavioral dataset of 52 colobine species to explore their evolutionary *** of this dataset suggested that the increase in group size may have evolved via home range expansion in response to the cold and heterogeneous climates found at higher altitudes or ***,we.developed a multi-benefits framework to interpret the formation of larger groups by integrating environmental *** cold and diverse environments,even smaller groups require larger home ranges to meet their dynamic survival *** spatiotemporal distribution of high-quality resources within these expanded home ranges facilitates more frequent interactions betwe.n groups,thereby encouraging social aggregation into larger *** process enhances the benefits of collabor

关键词： Social evolution Folivore paradox MLS Rhinopithecus roxellana Multi-benefits framework

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Designing Symmetric Gradient Honeycomb Structures with Carbon‑Coated Iron‑Based Composites for High‑Efficiency Microwave Absorption

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Nano-Micro Letters 2024年第11期16卷 224-241页

作者： Yu Zhang Shu‑Hao Yang Yue Xin Bo Cai Peng‑Fei Hu Hai‑Yang Dai Chen‑Ming Liang Yun‑Tong Meng Ji‑Hao Su Xiao‑Juan Zhang Min Lu guang‑sheng Wang School of Chemistry Beihang UniversityBeijing 100191People’s Republic of China School of Electronics and Information Zhengzhou University of Light IndustryZhengzhou 450002People’s Republic of China School of Chemical Engineering Northeast Electric Power UniversityJilin 132000People’s Republic of China College of Chemistry and Materials Engineering Beijing Technology and Business UniversityBeijing 100048People’s Republic of China

The impedance matching of absorbers is a vital factor affecting their microwave absorption(MA)*** this work,we.controllably synthesized Material of Institute Lavoisier 88C(MIL-88C)with varying aspect ratios(AR)as a precursor by regulating oil bath conditions,followe. by one-step thermal decomposition to obtain carbon-coated iron-based *** the precursor MIL-88C(Fe)preparation conditions,such as the molar ratio betwe.n metal ions and organic ligands(M/O),oil bath temperature,and oil bath time,influenced the phases,graphitization degree,and AR of the derivatives,enabling low filler loading,achieving we.l-matched impedance,and ensuring outstanding MA *** MOF-derivatives 2(MD_(2))/polyvinylidene Difluoride(PVDF),MD_(3)/PVDF,and MD4/PVDF absorbers all exhibited excellent MA properties with optimal filler loadings below 20 wt%and as low as 5 wt%.The MD_(2)/PVDF(5 wt%)achieved a maximum effective absorption bandwidth(EAB)of 5.52 GHz(1.90 mm).The MD_(3)/PVDF(10 wt%)possessed a minimum reflection loss(RL_(min))value of−67.4 at 12.56 GHz(2.13 mm).A symmetric gradient honeycomb structure(SGHS)was constructed utilizing the high-frequency structure simulator(HFSS)to further extend the EAB,achieving an EAB of 14.6 GHz and a RL_(min) of−59.0 *** research offers a viable inspiration to creating structures or materials with high-efficiency MA properties.

关键词： MIL-88C(Fe) Fe/Fe_(3)O_(4)/Fe_(3)C@C Controllable preparation Symmetric gradient honeycomb structure Microwave absorbing

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Modulated noble metal/2D MOF heterostructures for improved hydrogen storage of MgH_(2)

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Rare Metals 2024年第4期43卷 1672-1685页

作者： Zeng-Yi Li Li-Xian Sun Fen Xu Yu-Mei Luo Yong-Peng Xia sheng we. Chen-Chen Zhang Ri-guang Cheng Chao-Feng Ye Meng-Yuan Liu Ju-Lan Zeng Zhong Cao Hong-Ge Pan School of Material Science and Engineering Guilin University of Electronic TechnologyGuilin541004China School of Chemistry and Chemical Engineering Changsha University of Science and TechnologyChangsha410114China Institute of Science and Technology for New Energy Xi’an Technological UniversityXi’an710021China

The conjugation of external species with twodimensional(2D)materials has broad application *** this study,we.have explored the potential of noble metal/2D MOF heterostructures in hydrogen ***,the MgH_(2)-Ni-MOF@Pd system has shown remarkable hydrogen desorption/sorption performances,starting to liberate hydrogen at 1810C,which is 2300C lowe. than that of pristine *** the catalytic effect of Ni-MOF@Pd,the dehydrogenation apparent activation energy of MgH2 is noticeably decreased from(133.5±17.5)to(34.58±1.87)kJ·moL^(-1),and the hydrogenation apparent activation energy is reduced from(70.41±7.43)to(25.78±4.64)kJ·moL^(-1),which is lowe.ed by 63.4%.The fully-dehydrogenated MgH2-NiMOF@Pd composite rapidly uptakes hydrogen,with 2.62wt%at 100℃and 6.06 wt%at 150℃within 300 s,*** mechanism analysis of MgH2 catalyzed by Ni-MOF@Pd has revealed that the transformation of Mg_2Ni and Mg_2NiH_4 could act as a"hydrogen pump",providing numerous channels for fast diffusion and transport of hydrogen ***,in the dehydrogenation process,the element Pd reacts with MgH_(2)to form the MgPd alloy phase,which makes MgH_(2)take precedence to decompose through the Mg-Pd alloy rather than self-decomposition,further reducing thermal stability and improving de/hydrogenation *** synergistic effect of Mg-Pd,Mg_2Ni,and the special ultra-thin 2D sheet structure of the additive is the main reason for the good hydrogen storage property of MgH_(2)-Ni-MOF@*** findings provide inspiration for designing efficient multifunctional additives with unique morphologies to optimize the hydrogen desorption/sorption behaviors of hydrogen storage materials.

关键词： Hydrogen storage Magnesium hydride 2D metal-organic framework nanosheets Ni/Pd Synergistic catalysis

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Regulated reaction pathway of CO2 photoreduction into CH4 by metal atom pair sites

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Rare Metals 2024年第9期43卷 4620-4627页

作者： Dong-Po He guang-Bing Huang Jun Hu Yang Wu Xiao-Dong Li Qing-Xia Chen Shan Zhu we.-sheng Yan Jun-Fa Zhu Yang Pan Xing-Chen Jiao Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan University Hefei National Research Center for Physical Sciences at Microscale National Synchrotron Radiation LaboratoryUniversity of Science and Technology of China Max Planck Institute of Microstructure Physics State Grid Anhui Electric Powe. Research Institute

The carbon dioxide （CO2） reduction process involves complex protonation, making the resulting product often unpredictable. To achieve the desired product, it is crucial to manipulate the reaction steps. Herein, we.build the metal atom pair sites for selective CO2photoreduction into methane. As a prototype, Ni atom pair sites loaded on the Mo S2nanosheets we.e synthesized and verified by highresolution transmission electron microscopy （HRTEM）,X-ray photoelectron spectroscopy （XPS） and X-rayabsorption near edge structure spectra （XANES）. In-situ Fourier transform infrared spectroscopy （FTIR） monitors the*CHO group, a crucial intermediate in CH4production,during CO2photoreduction on the Ni-Mo S2nanosheets,whereas this monitoring is not observed for the Mo S2nanosheets. Also, theoretical calculations disclose that over the Ni-Mo S2nanosheet slab, the formation energy of*CHO intermediates is determined to be lowe. （0.585 e V） than the desorption energy of*CO intermediates for CO production（0.64 e V）, implying the higher selectivity of CH4production. Accordingly, the Ni-Mo S2nanosheets demonstrate a methane formation rate of 27.21μmol·g-1·h-1, coupled with an impressive electron selectivity of 94.2%.

关键词： Nanosheets

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