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A low-profile metamaterial absorber with ultrawideband reflectionless and wide-angular stability

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Defence Technology（防务技术） 2024年第4期34卷 258-268页

作者： Feihong lin Zhongming Yan Ping Wang yu Wang Hongcheng Zhou Haoran Lu School of Electrical Engineering Southwest Jiaotong UniversityChengdu 611756China Key Laboratory of Magnetic Suspension Technology and Maglev Vehicle Ministry of EducationChengdu 610031China China Academy of Launch Vehicle Technology Beijing 100076China

An ultrawideband reflectionless metamaterial absorber(MA)is proposed by replacing the metallic ground with the complementary split-ring resonator(CSRR)*** proposed MA exhibits-10 d B reflectivity spectrum from 1 GHz to 20 GHz,which maintains more than 90%absorption from 1.5 GHz to20 ***,it achieves angle stability for TE and TM polarization at oblique incident angles up to 40°and 65°,*** achieve broadband absorption spectrum,we have adopted a single-layer high-impedance surface(HIS)loaded with a double-layer magnetic material(MM)*** further realize the RCS reduction into a lower frequency range,we have employed the scattering cancellation technology into the traditional metallic ***,we have fabricated a sample exhibiting the 10 d B RCS reduction from 1 GHz to 20 GHz with a thickness of 10 *** and simulation results confirm that the proposed MA exhibits excellent comprehensive performance,making it suitable for many practical applications.

关键词： Metamaterial absorber(MA) Magnetic material(MM) High-impedance surface(HIS) Scattering cancellation technology Ultrawideband Wide-angular stable

Effects of shore-normal coastal structure on medium-to long-term embayed shoreline evolution

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Acta Oceanologica Sinica 2024年第2期43卷 58-66页

作者： Jitao yu yuanting Ding Pei Liu Renfu Fan lin Zhang Hainan Academy of Ocean and Fisheries Sciences Haikou 571126China Yazhou Bay Innovation Institute Hainan Tropical Ocean UniversitySanya 572025China School of Geography and Environmental Sciences Hainan Normal UniversityHaikou 571158China

Based on high-tide shoreline data extracted from 87 Landsat satellite images from 1986 to 2019 as well as using the linear regression rate and performing a Mann-Kendall(M–K)trend test,this study analyzes the linear characteristics and nonlinear behavior of the medium-to long-term shoreline evolution of Jinghai Bay,eastern Guangdong *** particular,shoreline rotation caused by a shore-normal coastal structure is *** results show that the overall shoreline evolution over the past 30 years is characterized by erosion on the southwest beach,with an average erosion rate of 3.1 m/a,and significant accretion on the northeast beach,with an average accretion rate of 5.6 m/*** of the M–K trend test indicate that significant shoreline changes occurred in early 2006,which can be attributed to shore-normal *** to that engineering construction,the shorelines are slightly eroded,where the average erosion rate is 0.7 m/***,after shore-normal engineering is performed,the shoreline is characterized by significant erosion(3.2 m/a)on the southwest beach and significant accretion(8.5 m/a)on the northeast beach,thus indicating that the shore-normal engineering at the updrift headland contributes to clockwise shoreline *** analysis shows that the clockwise shoreline rotation is promoted not only by longshore sediment transport processes from southwest to northeast,but also by cross-shore sediment transport *** findings are crucial for beach erosion risk management,coastal disaster zoning,regional sediment budget assessments,and further observations and predictions of beach morphodynamics.

关键词： shoreline rotation non-linear behavior longshore sediment transport cross-shore sediment transport embayed beach coastal structure

Synergistic strengthening mechanism of Ca^(2+)-sodium silicate to selective separation of feldspar and quartz

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International Journal of Minerals,Metallurgy and Materials 2024年第9期31卷 1985-1995页

作者： Bo lin Jingzhong Kuang Yiqiang Yang Zheyu Huang Delong Yang Mingming yu School of Resources and Environmental Engineering Jiangxi University of Science and TechnologyGanzhou 341000China Jiangxi Key Laboratory of Mining Engineering Ganzhou 341000China

Inhibitors are important for flotation separation of quartz and *** this study,a novel combined inhibitor was used to separate quartz and feldspar in near-neutral *** inhibition of the combined inhibitor was assessed by micro-flotation *** a series of detection methods were used to detect differences in the surface properties of feldspars and quartz after flotation reagents and put forward the synergistic strengthening *** outcomes were pointed out that pre-mixing combined inhibitors were more effective than the addition of Ca^(2+)and SS in sequence under the optimal proportion of 1:5.A concentrate from artificial mixed minerals that was characterized by a high quartz grade and a high recovery was acquired,and was found to be 90.70wt% and 83.70%,*** was demonstrated that the combined inhibitor selectively prevented the action of the collector and feldspar from Fourier-transform infrared(FT-IR)and adsorption capacity *** results of X-ray photoelectron spectroscopy(XPS)indicated that Ca^(2+)directly interacts with the surface of quartz to increase the adsorption of *** contrast,the chemistry property of Al on the feldspar surface was altered by combined inhibitor due to Na^(+)and Ca^(2+)taking the place of K^(+),resulting in the composite inhibitor forms a hydrophilic structure,which prevents the adsorption of the collector on the surface of feldspar by interacting with the Al active *** combination of Ca^(2+)and SS synergically strengthens the difference of collecting property between quartz and feldspar by collector,thus achieving the effect of efficient separation.A new strategy for flotation to separate quartz from feldspar in near-neutral pulp was provided.

关键词： feldspar quartz Ca^(2+)-sodium silicate selective adsorption flotation separation

Non-synchronous vibration of rotor blade in a six-stage transonic compressor

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Chinese Journal of Aeronautics 2024年第8期37卷 36-48页

作者： Ronghui CHENG Zhuo WANG Huawei yu lin DU Yi ZHANG Xiaofeng SUN Aeroengine Research Institute Beihang UniversityBeijing 102206China School of Energy and Power Engineering Beihang UniversityBeijing 102206China

This paper presents an experimental study on the Non-Synchronous Vibration(NSV)in a six-stage transonic *** first part of the paper describes the NSV phenomenon of Rotor 1,which occurs when both Stator 1(S1)and Stator 2(S2)or S1 only are *** measurements and analysis are carried out for the former case through the unsteady wall pressure and the Blade Strain(BS).The spinning mode theory used in the rotor/stator interaction noise is employed to explain the relation between the circumferential wave number of the aerodynamic disturbance and the Nodal Diameter(ND)of the blade *** variations of the vibration amplitudes of different blades and the Inter-Blade Phase Angles(IBPAs)at different moments suggest that the evolution of NSV is a highly nonuniform phenomenon along the circumferential *** addition,the difference between the wall-pressure spectra generated by the NSV and the classic flutter has been *** the second part,the variations of aerodynamic loading due to the adjustment of the staggers of the Inlet Guide Vane(IGV),S1 and S2 have been *** is found that closing S1 only can result in a great fluctuation to the performance of the front stages,which might be detrimental to the flow organization and increase the risk of *** contrast,the effect of closing S2 only on the performance of the first two stages appears to be slighter relatively.

关键词： Transonic compressor Non-synchronous vibration Modal analysis Aerodynamic loading Nodal diameter

Extraction method of typical IEQ spatial distributions based on low-rank sparse representation and multi-step clustering

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Building Simulation 2024年第6期17卷 983-1006页

作者： yuren Yang Yang Geng Hao Tang Mufeng yuan Juan yu Borong lin School of Architecture Tsinghua UniversityBeijingChina Key Laboratory of Eco Planning&Green Building Ministry of EducationTsinghua UniversityBeijingChina

Indoor environment quality(IEQ)is one of the most concerned building performances during the operation *** non-uniform spatial distribution of various IEQ parameters in large-scale public buildings has been demonstrated to be an essential factor affecting occupant comfort and building energy ***,IEQ sensors have been widely employed in buildings to monitor thermal,visual,acoustic and air ***,there is a lack of effective methods for exploring the typical spatial distribution of indoor environmental quality parameters,which is crucial for assessing and controlling non-uniform indoor *** this study,a novel clustering method for extracting IEQ spatial distribution patterns is ***,representation vectors reflecting IEQ distributions in the concerned space are generated based on the low-rank sparse ***,a multi-step clustering method,which addressed the problems of the“curse of dimensionality”,is designed to obtain typical IEQ distribution patterns of the entire indoor *** proposed method was applied to the analysis of indoor thermal environment in Beijing Daxing international airport *** a result,four typical temperature spatial distribution patterns of the terminal were extracted from a four-month monitoring,which had been validated for their good *** typical patterns revealed typical environmental issues in the terminal,such as long-term localized overheating and temperature increases due to a sudden influx of *** extracted typical IEQ spatial distribution patterns could assist building operators in effectively assessing the uneven distribution of IEQ space under current environmental conditions,facilitating targeted environmental improvements,optimization of thermal comfort levels,and application of energy-saving measures.

关键词： indoor environment quality(IEQ) thermal environment spatial distribution temperature field low-rank sparse representation(LRSR) clustering

Copper-mediated assembly of SO_(2)F group via radical fluorine-atom transfer strategy

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Chinese Chemical Letters 2024年第9期35卷 4-5页

作者： yu-yu Tan lin-Heng He Wei-Min He School of Electrical Engineering University of South ChinaHengyang 421001China

Because of the unique reactivity of sulfonyl fluoride(SO_(2)F)group,such compound has found increasing applications in the areas of organic synthesis,new drug development,pesticide,material science and click chemistry,*** is of current interest to develop novel strategies and methods for the facile preparation of sulfonyl fluorides in a green and highly efficient manner[1,2].Although the traditional approach for the synthesis of sulfonyl fluorides relies on the nucleophilic substitution of fluoride atom with sulfonyl chlorides.

关键词： fluoride synthesis fluorine

Recommendations for articles and reviews in colorectal cancerrelated research at the year-end of 2023

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World Journal of Gastroenterology 2024年第30期30卷 3548-3553页

作者： Wen-yu Luan Hao lin Yan-Dong Miao Department of Cancer Center The Yantai Affiliated Hospital of Binzhou Medical UniversityThe Second Medical College of Binzhou Medical UniversityYantai 264100Shandong ProvinceChina

As peer reviewers of the World Journal of Gastroenterology,our weekly routine involves immersing ourselves in the newly published issue,particularly focusing on the realm of colorectal cancer(CRC)*** diligently sift through various contributions,ranging from comprehensive reviews to original articles and other scholarly *** meticulous examination,we discern the most notable papers,delving into each with careful scrutiny to distill their merits and ***,this undertaking demands considerable time and ***,it stands as an indispensable pursuit,affording us a profound comprehension of the latest breakthroughs in CRC ***,these meticulously curated selections furnish readers with invaluable resources,serving as enduring references for the nuanced exploration of this dynamic field.

关键词： Colorectal cancer Molecular mechanism Genetic marker Application of new technologies Diagnosis Treatment

White light emission in 0D halide perovskite[(CH_(3))_(3)S]_(2)SnCl_(6)·H_(2)O crystals through variation of doping ns^(2) ions

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Frontiers of Optoelectronics 2024年第1期17卷 57-66页

作者： Yitong lin yu Zhong Yangpeng lin Jiawei lin Lei Pang Zhilong Zhang Yi Zhao Xiao‑Ying Huang Ke‑Zhao Du Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering Collage of Chemistry and Material ScienceFujian Normal UniversityFuzhou 350007China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Qinghai Environmental Monitoring Center Xining 810000China Strait Institute of Flexible Electronics(SIFE Future Technologies)Fujian Normal University and Strait Laboratory of Flexible Electronics(SLoFE)Fuzhou 350007China Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China

With the rapid development of white LEDs,the research of new and efficient white light emitting materials has attracted increasing *** dimensional(0D)organic–inorganic hybrid metal halide perovskites with superior luminescent property are promising candidates for LED application,due to their abundant and tailorable ***,[(CH_(3))_(3)S]_(2)SnCl_(6)・H_(2)O is synthesized as a host for dopant ions Bi^(3+)and Sb^(3+).The Sb^(3+)doped,or Bi^(3+)/Sb^(3+)co-doped,[(CH_(3))3S]_(2)SnCl_(6)・H_(2)O has a tunable optical emission spectrum by means of varying dopant ratio and excitation *** a result,we can achieve single-phase materials suitable for emission ranging from cold white light to warm white *** intrinsic mechanism is examined in this work,to clarify the dopant effect on the optical *** high stability of title crystalline material,against water,oxygen and heat,makes it promising for further application.

关键词： 0D Metal halide White light Perovskite Ions doping Excitation dependent

Atomically Dispersed Ruthenium Catalysts with Open Hollow Structure for Lithium-Oxygen Batteries

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Nano-Micro Letters 2024年第2期16卷 154-164页

作者： Xin Chen yu Zhang Chang Chen Huinan Li yuran lin Ke yu Caiyun Nan Chen Chen Beijing Advanced Innovation Center for Materials Genome Engineering Institute of Solid State ChemistryUniversity of Science and Technology BeijingBeijing 100083People’s Republic of China Engineering Research Center of Advanced Rare Earth Materials Department of ChemistryTsinghua UniversityBeijing 100084People’s Republic of China Beijing Key Laboratory of Energy Conversion and Storage Materials Institution College of ChemistryBeijing Normal UniversityBeijing 100875People’s Republic of China

Lithium–oxygen battery with ultrahigh theoretical energy density is considered a highly competitive next-generation energy storage device,but its practical application is severely hindered by issues such as difficult decomposition of discharge products at ***,we have developed N-doped carbon anchored atomically dispersed Ru sites cathode catalyst with open hollow structure(h-RuNC)for Lithium–oxygen *** one hand,the abundance of atomically dispersed Ru sites can effectively catalyze the formation and decomposition of discharge products,thereby greatly enhancing the redox *** the other hand,the open hollow structure not only enhances the mass activity of atomically dispersed Ru sites but also improves the diffusion efficiency of catalytic ***,the excellent activity from atomically dispersed Ru sites and the enhanced diffusion from open hollow structure respectively improve the redox kinetics and cycling stability,ultimately achieving a high-performance lithium–oxygen battery.

关键词： Atomically dispersed Open hollow structure Discharge product Lithium Oxygen battery