检索结果-南通市图书馆

Synthesis of high-entropy MXenes with high-efficiency electromagnetic wave absorption

Journal of Advanced Ceramics 2023年第10期12卷 1902-1918页

作者： Linjing Qiao Jianqiang Bi Guandong Liang Yao Yang Hongyi wang shaoyin wang Key Laboratory for Liquid–Solid Structural Evolution and Processing of Materials Ministry of EducationShandong UniversityJinan 250061China School of Materials Science and Engineering Shandong UniversityJinan 250061China

High-entropy MXenes,as a new emerging class of materials,possess diverse compositions,unexpected physicochemical characteristics,and great potentials for electromagnetic(EM)wave ***,two single-to-few-layer high-entropy MXenes,(Mo_(0.25)Cr_(0.25)Ti_(0.25)V_(0.25))3 C2 T_(x)and(Mo_(0.2)Cr_(0.2)Nb_(0.2)Ti_(0.2)V_(0.2))_(4)C_(3)T_(x),were synthesized for the first *** the exfoliation and delamination processes,the structural,morphological,and compositional evolutions were analyzed,verifying the successful formation of single-to-few-layer two-dimensional MXene *** indicate that with the filling content of only 35 wt%,MXene powder filled composites exhibit high-efficiency EM wave absorption *** f-(Mo_(0.25)Cr_(0.25)Ti_(0.25)V_(0.25))_(3)C_(2)T_(x)possesses the minimum reflection loss(RL min)of−45.0 dB with the matching thickness of 1.52 mm and the maximum effective absorption bandwidth(EAB)of 5.6 GHz at 1.65 mm ***,f-(Mo_(0.2)Cr_(0.2)Nb_(0.2)Ti_(0.2)V_(0.2))_(4)C_(3)T_(x)can attain an RL min of−52.8 dB with the thickness of 1.58 mm and an optimum EAB value of 3.6 GHz at 1.50 *** satisfactory EM wave absorption efficiency and bandwidth,thin matching thickness,and low filling content prove the lightweight advantage and great application potential of high-entropy MXenes in EM wave *** this work,the high-entropy strategy is applied to tune the EM wave absorption performances for ***,high-entropy engineering is expected to provide control and tunability of many other properties,such as electrochemical,catalytic,and mechanical behaviors.

关键词： high-entropy MAX phase MXene electromagnetic wave absorption

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Synthesis and electromagnetic wave absorption performances of a novel(Mo_(0.25)Cr_(0.25)Ti_(0.25)V_(0.25))_(3)AlC_(2)high-entropy MAX phase

引用

Journal of Materials Science & Technology 2023年第6期137卷 112-122页

作者： Linjing Qiao Jianqiang Bi Guandong Liang Chen Liu Zhuangzhuang Yin Yao Yang Hongyi wang shaoyin wang Mengmeng Shang Weili wang Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of EducationShandong UniversityJinan 250061China School of Materials Science and Engineering Shandong UniversityJinan 250061China

Herein,a novel kind of high-entropy MAX phases,(Mo_(0.25)Cr_(0.25)Ti_(0.25)V_(0.25))_(3)AlC_(2)powders were success-fully synthesized by a newly proposed two-step solid state reaction *** oxidation experiments demonstrate that the oxidation products of Al_(2)Mo_(3)O_(12) and rutile TiO 2 are formed at about 600 and 800℃,***,the dielectric and electromagnetic(EM)wave absorption properties of(Mo_(0.25)Cr_(0.25)Ti_(0.25)V_(0.25))_(3)AlC_(2)powders and those after oxidation at different temperatures were also *** results show that the as-synthesized(Mo_(0.25)Cr_(0.25)Ti_(0.25)V_(0.25))_(3)AlC_(2)powders possess excellent EM wave absorption performances with the minimum reflection loss(RL)of-45.80 dB(at 1.7 mm thickness)and the maximum effective absorption bandwidth(E AB)of 3.6 GHz(at 1.5 mm thickness).After oxidation at 400-800℃,due to the coupling of conductivity loss and polarization loss,(Mo_(0.25)Cr_(0.25)Ti_(0.25)V_(0.25))_(3)AlC_(2)powders can retain good EM wave absorption properties in a certain frequency *** this paper,the effects of oxidation on EM wave absorption properties of high-entropy MAX phases were systematically investigated for the first *** work manifests that high-entropy MAX phases are promising EM wave absorbing candidates and can maintain good EM wave absorption performances after oxidation.

关键词： (Mo_(0.25)Cr_(0.25)Ti_(0.25)V_(0.25))_(3)AlC_(2) High-entropy MAX phase Two-step synthesis Oxidation Electromagnetic wave absorption

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Separation of Atmospheric Circulation Patterns Governing Regional Variability of Arctic Sea Ice in Summer

引用

Advances in Atmospheric Sciences 2023年第12期40卷 2344-2361页

作者： shaoyin wang Jiping LIU Xiao CHENG Richard JGREATBATCH Zixin WEI Zhuoqi CHEN Hua LI School of Geospatial Engineering and Science Sun Yat-sen Universityand Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519000China Department of Atmospheric and Environmental Sciences State University of New York at AlbanyAlbany NY 12222USA GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel 24105Germany Joint International Research Laboratory of Climate and Environment Change Nanjing University of Information Science&TechnologyNanjing 210044China Faculty of Mathematics and Natural Sciences Christian Albrechts University of KielKiel 24118Germany University Corporation for Polar Research Zhuhai 519000China

In recent decades,Arctic summer sea ice extent(SIE)has shown a rapid decline overlaid with large interannual variations,both of which are influenced by geopotential height anomalies over Greenland(GL-high)and the central Arctic(CA-high).In this study,SIE along coastal Siberia(Sib-SIE)and Alaska(Ala-SIE)is found to account for about 65%and 21%of the Arctic SIE interannual variability,*** in Ala-SIE is related to the GL-high,whereas variability in Sib-SIE is related to the CA-high.A decreased Ala-SIE is associated with decreased cloud cover and increased easterly winds along the Alaskan coast,promoting ice-albedo feedback.A decreased Sib-SIE is associated with a significant increase in water vapor and downward longwave radiation(DLR)along the Siberian *** years 2012 and 2020 with minimum recorded ASIE are used as *** to climatology,summer 2012 is characterized by a significantly enhanced GL-high with major sea ice loss along the Alaskan coast,while summer 2020 is characterized by an enhanced CA-high with sea ice loss focused along the Siberian *** 2012,the lack of cloud cover along the Alaskan coast contributed to an increase in incoming solar radiation,amplifying ice-albedo feedback there;while in 2020,the opposite occurs with an increase in cloud cover along the Alaskan coast,resulting in a slight increase in sea ice *** the Siberian coast,increased DLR in 2020 plays a dominant role in sea ice loss,and increased cloud cover and water vapor both contribute to the increased DLR.

关键词： Arctic sea ice Arctic circulation patterns shortwave and longwave radiation cloud cover water vapor

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Assessing the degree of impact from iceberg activities on penguin colonies of Clarence Island

引用

Acta Oceanologica Sinica 2024年第9期43卷 105-109页

作者： Hong Lin Xiao Cheng Teng Li Qian Shi Qi Liang Xinyu Meng shaoyin wang Lei Zheng School of Geospatial Engineering and Science Sun Yat-sen Universityand Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Key Laboratory of Comprehensive Observation of Polar Environment(Sun Yat-sen University) Ministry of EducationZhuhai 519082China School of Geography and Planning Sun Yat-sen UniversityGuangzhou 510006China Guangdong Key Laboratory for Urbanization and Geo-simulation Sun Yat-sen UniversityGuangzhou 510275China

During August and September 2023,three giant icebergs,each bigger than Paris,successively grazed Clarence Island in the northeast of the Antarctic Peninsula,a home to a population of over 100000 *** incident may serve as a clarion call for the increasing iceberg calving due to global warming and its subsequent impact on the Antarctic *** we investigate this unexpected event and employ historical records and probabilistic analyses of iceberg grounding to assess the degree of impact on penguin colonies of Clarence *** the eleven colonies,there is one with low impact,eight with medium impact,and two with high *** low-impact colony,Cape Lloyd,is located in the northern part of the island,while the high-impact colonies,False Ridge and Pink Pool,are in the *** eight medium-impact colonies are distributed along both the eastern and western coasts of the *** study provides essential support for evaluating the impact of iceberg activity on penguin *** argue that penguin colonies located in areas prone to iceberg drift,such as Clarence Island,may become more vulnerable to the heightened risk of iceberg collisions or groundings in the warming ***,we hope the public will become more aware of the grave impacts of climate change on penguins and underscore the urgent need for effective conservation strategies.

关键词： iceberg penguin remote sensing extreme events climate change

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of grain size on mechanical properties and tribological behavior of size-tunable high entropy diboride ceramics obtained by two-step SPS sintering

引用

Journal of Advanced Ceramics 2024年第11期13卷 1835-1843页

作者： Yao Yang Jianqiang Bi Linjing Qiao Guandong Liang Shuyong Liang Shushuai Liu shaoyin wang Hongyu Gong Zhao Qian Jinwang Shi Weiqiang Li Key Laboratory for Liquid–Solid Structural Evolution and Processing of Materials Ministry of EducationShandong UniversityJinan 250061China School of Materials Science and Engineering Shandong UniversityJinan 250061China Shandong Huamei New Material Technology Co. Ltd.Weifang 261200China

High-entropy diboride(HEB)ceramics constitute a novel class of ultrahigh-temperature ceramics that are appealing for applications in extreme *** relative density and grain size play important roles in tailoring the mechanical properties and wear resistance of HEBs,affecting their applications,such as high-temperature structural parts and thermal protection *** this study,highly dense(HfZrTaVNb)B_(2) ceramics with size-tunable microstructures were successfully synthesized by spark plasma sintering combined with an ingenious two-step *** effects of grain size on the mechanical properties and wear resistance of(HfZrTaVNb)B_(2) ceramics were comprehensively *** results indicated that the smaller grain size led to higher hardness and fracture toughness,and the relationship between hardness and grain size fitted the Hall–Petch equation *** particular,the sample featuring a grain size of 1.64µm and 97.6%density had the highest hardness and fracture toughness,26.7 GPa and 4.6 MPa·m^(1/2),***,it also demonstrated optimal wear resistance,displaying a minimal wear rate of only 2.53×10^(−6) mm^(3)/(N·m)under a 20 N *** analysis revealed that the primary wear mechanism observed in(HfZrTaVNb)B_(2) was oxidative wear under a 5 N *** a 10 N load,the wear mechanism comprised both oxidative and fracture *** wear mechanism became more complex and involved oxidation wear,fracture wear,abrasive wear,and fatigue wear at a 20 N load.

关键词： high-entropy diborides(HEBs) two-step sintering mechanical properties tribology microstructure regulation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

微波辅助水蒸气蒸馏法提取金柑果皮精油及其对桔小实蝇引诱活性的影响

引用

中国食品学报 2014年第4期14卷 37-44页

作者：王绍引张怡郑宝东福建农林大学食品科学学院福州350002

采用微波辅助水蒸气蒸馏法提取金柑果皮精油,研究其对桔小实蝇的引诱活性。试验结果表明:由响应面优化试验设计所得方程达到显著水平,果皮精油的最佳提取工艺条件为夹带剂含量3%,提取时间63 min,液料比20∶1(mL/g),实际测得的精油提取率... 详细信息

采用微波辅助水蒸气蒸馏法提取金柑果皮精油,研究其对桔小实蝇的引诱活性。试验结果表明:由响应面优化试验设计所得方程达到显著水平,果皮精油的最佳提取工艺条件为夹带剂含量3%,提取时间63 min,液料比20∶1(mL/g),实际测得的精油提取率为4.3%。试验因素影响程度为:液料比>夹带剂含量>提取时间。不同浓度的金柑果皮精油对桔小实蝇雌虫均有显著的引诱活性,经单因素方差分析,当测试时间为10 min时选择处理与对照的雌虫数量达到差异显著水平(P<0.05);当测试时间为40 min时,10μL/mL和20μL/mL金柑精油对桔小实蝇雌虫的引诱率最高,分别为81.0%和88.6%。

关键词：金柑皮精油微波水蒸气蒸馏响应面引诱活性

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Fingerprint of COVID-19 in Arctic sea ice changes

引用

Science Bulletin 2021年第20期66卷 2050-2053页

作者： Zhuoqi Chen shaoyin wang Yufang Ye Jiping Liu Georg Heygster Mohammed Shokr Fengming Hui Xiao Cheng School of Geospatial Engineering and Science Sun Yat-sen UniversityZhuhai 519000China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519000China Department of Atmospheric and Environmental Sciences State University of New York at AlbanyAlbanyNY 12222USA GEORG-Lab(Geophysical Remote Sensing Lab) Bremen 28359Germany Science and Technology Branch Environment and Climate Change CanadaToronto ON M3H 5T4Canada University Corporation for Polar Research Zhuhai 519000China

Arctic sea ice plays an essential role in regional and global climate by dynamic processes and feedbacks associated with its high reflectivity, thermal insulation especially in presence of snow cover, and brine rejection [1]. Both observations and model simulations show that Arctic sea ice extent has dramatically declined and thinned in the past few decades [2] in response to global warming and cumulative anthropogenic greenhouse gas(GHG)emissions [3,4].

关键词：北极海冰 Arctic greenhouse

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

砂率对C60、C80、C100混凝土新拌性能与抗压强度的影响

引用

江苏建材 2021年第2期 25-28页

作者：王少寅苏州交通工程集团有限公司江苏苏州215000

针对C60、C80、C100强度等级混凝土,研究了砂率对其新拌性能和抗压强度的影响规律,结果表明:不同砂率下的C60、C80、C100均不发生泌水现象,增加砂率,需要提高减水剂掺量才能达到相应工作性,同时改善对粗骨料的包裹性;砂率对C60、C80、C... 详细信息

针对C60、C80、C100强度等级混凝土,研究了砂率对其新拌性能和抗压强度的影响规律,结果表明:不同砂率下的C60、C80、C100均不发生泌水现象,增加砂率,需要提高减水剂掺量才能达到相应工作性,同时改善对粗骨料的包裹性;砂率对C60、C80、C100含气量、表观密度无明显影响,C100含气量明显高于C60、C80;砂率增加,C60抗压强度呈现逐渐增加的趋势,C80抗压强度呈现先增加后降低的趋势,砂率在36.5%时抗压强度最高,砂率对C100抗压强度影响不显著。

关键词：砂率坍落扩展度含气量抗压强度

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

An ESR Study on Singlet Oxygen Photoproduction of the Meso-Tetrakis-(Substituted Phenyl) Porphine Derivatives

引用

Chemical Research in Chinese Universities 1990年第4期6卷 313-316页

作者： Chen Jiyao, -Lu Yameng, Chen Shiming and Cai Hualxin (Department of Physics and Center of Analysis and Measurements, Fudan University, Shanghai)Xu Deyu and wang shaoyin (Research Laboratory of Antimalaria Pharmaceuticals, No. 2 Military Medical University, Shanghai)

The ability of meso-tetrakis- (substituted phenyl) porphine derivatives for photo-generating singlet oxygen (O2) is studied by ESR spectrometry. The results show that the singlet oxygen yields of most of porphine derivatives are higher than that of HPD. It is also exhibited that the nature and structure of the substituent at the meso position are closely related to the photo-sensitizing ability of meso-tetrakis-(substituted phenyl) porphine.

关键词： Porphine Singlet oxygen ESR

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

超声引导下旋转进针穿刺法对细血管置入中心静脉导管一次成功率的影响

引用

安徽医药 2019年第6期23卷 1146-1148页

作者：王少银胡俊六安市人民医院神经外科安徽六安237005 六安市人民医院肿瘤外科安徽六安237005

目的探讨超声引导下旋转进针穿刺法对血管直径<3.5 mm病人首次置管成功率的影响。方法选取六安市人民医院2016年1—12月血管直径<3.5 mm的置管病人33例作为对照组,选取2017年1—10月血管直径<3.5 mm的置管病人34例为研究组。对照组采用... 详细信息

目的探讨超声引导下旋转进针穿刺法对血管直径<3.5 mm病人首次置管成功率的影响。方法选取六安市人民医院2016年1—12月血管直径<3.5 mm的置管病人33例作为对照组,选取2017年1—10月血管直径<3.5 mm的置管病人34例为研究组。对照组采用传统直刺的手法穿刺;研究组以旋转进针的手法进行穿刺。比较两组的一次性置管成功率。结果研究组一次性置管成功28例,成功率为82.35%,高于对照组的17例(51.51%),差异有统计学意义(χ~2=7.221,P=0.007)。结论旋转进针的穿刺手法能有效提高经细血管置入中心静脉导管一次性成功率,值得临床推广。

关键词：旋转进针穿刺法血管直径经外周静脉置入中心静脉导管

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：