检索结果-南通市图书馆

Miura origami based reconfigurable polarization converter for multifunctional control of electromagnetic waves

Photonics Research 2024年第3期12卷 581-586页

作者： ZHIBIAO ZHU YONGFENG LI ZHE QIN LIXIN JIANG WENJIE WANG HONGYA CHEN JIAFU WANG yongqiang pang SHAOBO QU Shaanxi Key Laboratory of Artificially-Structured Functional Materials and Devices Air Force Engineering UniversityXi’an 710051China School of Electronic Science and Engineering Xi’an Jiaotong UniversityXi’an 710049China

Polarization is one of the basic characteristics of electromagnetic(EM)waves,and its flexible control is very important in many practical *** present,most of the multifunction polarization metasurfaces are electrically tunable based on PIN and varactor diodes,which are easy to operate and have strong real-time ***,there are still some problems in them,such as few degrees of freedom of planar structure control,complex circuit,bulky sample,and high *** view of these shortcomings,this paper proposes a Miura origami based reconfigurable polarization conversion metasurface for multifunctional control of EM *** interaction between the electric dipoles is changed by adjusting the folding angleθ,thereby tuning the operating frequency of the polarization conversion and the polarization state of the reflected *** mechanical control method brings more degrees of freedom to manipulate EM *** the processed sample is with lightweight and low *** verify the performance of the proposed origami polarization converter,a Miura origami structure loaded with metal split rings is designed and *** operating frequency of the structure can be tuned in different folding *** addition,by controlling the folding angleθ,linear-to-linear and linear-to-circular polarization converters can be realized at different folding *** proposed Miura origami polarization conversion metasurface provides a new idea for reconfigurable linear polarization conversion and multifunctional devices.

关键词： polarization reconfigurable tuning

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

风沙土混拌刀具的改良设计与试验

引用

中国农业科技导报 2024年第4期26卷 87-96页

作者：李明董帅庞永强燕洁华叶汪忠内蒙古农业大学能源与交通工程学院呼和浩特010018

为解决风沙土改良设备研制中存在的核心问题,探讨混拌刀具与风沙土-改土材料间相互作用机理,以国标旋耕刀IT245为基础,分析其作用原理,在此基础上设计了专用于风沙土改良的混拌刀具,通过离散元仿真模拟及室内沙槽试验,以改土材料体积比... 详细信息

为解决风沙土改良设备研制中存在的核心问题,探讨混拌刀具与风沙土-改土材料间相互作用机理,以国标旋耕刀IT245为基础,分析其作用原理,在此基础上设计了专用于风沙土改良的混拌刀具,通过离散元仿真模拟及室内沙槽试验,以改土材料体积比为评价指标对国标刀及专用刀具5层深度下的混拌效果进行分析。结果显示,风沙土混拌刀具偏转角度越大,改土材料体积比越大,当深度150—120 mm、偏转角为60°时达到最大值(35.67%);风沙土混拌刀具弯折角越大,改土材料体积比越大,当深度150—120 mm、弯折角为130°时达到最大值(36.02%)。风沙土混拌刀具与国标旋耕刀IT245混拌效果相比,深度越浅,改土材料体积比越大,混合效果越好,在深度90—60、60—30 mm时,偏转角60°的风沙土混拌刀具作业后改土材料体积比分别比IT245增加了3.19%、5.11%。研究结果为风沙土混拌刀具及风沙土治理机械的设计与优化提供依据。

关键词：风沙土改土材料离散元混拌刀具混拌效果

来源：

维普期刊数据库博看期刊

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

精准变量全幅式物料施撒装置的设计与仿真分析

引用

农机化研究 2024年第6期46卷 96-102,108页

作者：李明庞永强董帅燕洁华叶汪忠内蒙古农业大学能源与交通工程学院呼和浩特010018

为进一步解决风沙土改良作业机械化率低的问题,提高改土材料机械化铺施效率,提出了一种精准可控变量的固体物料施撒方案,设计了一种精准变量全幅式物料施撒装置。通过对物料施撒过程的受力和运动分析,以物料颗粒为研究对象,建立其在幅... 详细信息

为进一步解决风沙土改良作业机械化率低的问题,提高改土材料机械化铺施效率,提出了一种精准可控变量的固体物料施撒方案,设计了一种精准变量全幅式物料施撒装置。通过对物料施撒过程的受力和运动分析,以物料颗粒为研究对象,建立其在幅板上运动的动力学模型。基于离散元法对物料施撒过程进行仿真试验研究,建立试验因素与试验指标之间的二次回归模型,并进行单因素影响分析、方差分析及目标参数优化。结果表明:各因素对分布变异系数影响大小的先后顺序分别为调量板、排肥轮轴转速、幅板个数;经过中心组合响应曲面试验设计进行参数优化可知:当幅板个数为7、调量板位置为0mm、排肥轮轴转速为40r/min时,分布变异系数最小为7.36%,铺料最均匀,厚度最大,满足施撒作业的要求。研究结果可为风沙土改良机械及农业固体施肥机械设计提供参考。

关键词：物料施撒装置均匀性精准变量离散元法施撒性能

来源：

维普期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Digital Light Processing 3D-Printed Ceramic Metamaterials for Electromagnetic Wave Absorption

引用

Nano-Micro Letters 2022年第7期14卷 279-292页

作者： Rui Zhou Yansong Wang Ziyu Liu yongqiang pang Jianxin Chen Jie Kong MOE Key Lab of Materials Physics and Chemistry in Extraordinary Conditions Shaanxi Key Lab of Macromolecular Science and TechnologySchool of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072People’s Republic of China Key Laboratory of Optical System Advance Manufacturing Technology Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033People’s Republic of China School of Electronic Science and Engineering Xi’an Jiaotong UniversityXi’an 710049People’s Republic of China

Combining 3D printing with precursor-derived ceramic for fabricating electromagnetic(EM) wave-absorbing metamaterials has attracted great attention. This study presents a novel ultraviolet-curable polysiloxane precursor for digital light processing(DLP) 3D printing to fabricate ceramic parts with complex geometry, no cracks and linear shrinkage. Guiding with the principles of impedance matching, attenuation, and effective-medium theory, we design a crosshelix-array metamaterial model based on the complex permittivity constant of precursor-derived ceramics. The corresponding ceramic metamaterials can be successfully prepared by DLP printing and subsequent pyrolysis process, achieving a low reflection coefficient and a wide effective absorption bandwidth in the X-band even under high temperature. This is a general method that can be extended to other bands, which can be realized by merely adjusting the unit structure of meta-materials. This strategy provides a novel and effective avenue to achieve “target-design-fabricating” ceramic metamaterials, and it exposes the downstream applications of highly efficient and broad EM wave-absorbing materials and structures with great potential applications.

关键词： Electromagnetic wave absorption Metamaterial Precursor-derived ceramics 3D printing

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

针灸综合疗法较激素治疗急性期周围性面神经麻痹结局指标的Meta分析

引用

中国民族民间医药 2024年第9期33卷 100-106页

作者：马涵庞永强张茜徐彦龙甘肃中医药大学甘肃兰州730000 甘肃省中医院甘肃兰州730000

目的:系统评价针灸综合疗法较激素治疗急性期周围性面神经麻痹的疗效差异。方法:通过计算机检索中国知网数据库(CNKI)、中国生物医学文献数据库(SinoMed)、维普中文科技期刊数据库(VIP)、万方数据知识服务平台(WanFang Data)、PubMed、C... 详细信息

目的:系统评价针灸综合疗法较激素治疗急性期周围性面神经麻痹的疗效差异。方法:通过计算机检索中国知网数据库(CNKI)、中国生物医学文献数据库(SinoMed)、维普中文科技期刊数据库(VIP)、万方数据知识服务平台(WanFang Data)、PubMed、Cochrane图书馆(Cochrane Library)、Web Of Science、Embase数据库。检索语言为中文和英文。检索时限均从建库至2023年1月21日,由2位研究者独立对纳入文献进行资料提取和质量评价后,采用RevMan 5.4统计软件进行Meta分析。结果:共纳入8篇文献,病例数896例,Meta分析结果提示:①针灸综合疗法治疗急性期PFP的愈显率高于激素疗法(OR=2.36,95%CI[1.43,3.90],Z=3.35,P=0.0008);②针灸综合疗法对于急性PFP患者H-B面神经功能的改善优于激素疗法(WMD=-0.27,95%CI[-0.49,-0.06],Z=2.50,P=0.01);③针灸综合疗法治疗急性期PFP的治愈时间短于激素疗法(WMD=-0.63,95%CI[-0.92,-0.34],Z=4.22,P<0.0001);④纳入文献中仅有2篇报道了并发症发生率的观察指标,且两组数据比较无统计学意义,故无法判断哪种疗法能降低并发症的发生率;⑤在病情发展方面,针灸综合疗法介入后的急性期PFP进展过程要慢于当激素介入时(OR=0.34,95%CI[0.17,0.67],Z=3.08,P=0.002)。结论:基于本次Meta分析,针灸综合疗法治疗急性期PFP安全有效,可以提高愈显率,改善面神经功能,缩短痊愈所需时间,而其在上述各指标方面与激素的比较中占有优势,故当以针灸综合疗法干预急性期PFP时,可以考虑不执着于选择激素,但此次系统评价仍较为局限,未来还需更多高质量、大样本的临床对照试验为针灸与激素干预急性期PFP时的差异性比较提供更加客观明确的循证依据。

关键词：急性期周围性面神经麻痹针灸综合疗法激素系统评价 Meta分析

来源：

维普期刊数据库博看期刊

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

“三调针法”联合重复功能性磁刺激治疗脊髓损伤后逼尿肌无力型神经源性膀胱临床疗效观察

引用

北京中医药大学学报 2024年第6期47卷 826-834页

作者：庞永强徐秀梅徐彦龙程子潇董春璇张燕琴张茜马涵甘肃中医药大学兰州730000 甘肃省中医院

目的观察“三调针法”联合重复功能性磁刺激(rFMS)治疗脊髓损伤后逼尿肌无力型神经源性膀胱的临床疗效。方法120例脊髓损伤后逼尿肌无力型神经源性膀胱患者按照随机数字表法分为常规治疗组、“三调针法”治疗组、rFMS治疗组和综合治疗组... 详细信息

目的观察“三调针法”联合重复功能性磁刺激(rFMS)治疗脊髓损伤后逼尿肌无力型神经源性膀胱的临床疗效。方法120例脊髓损伤后逼尿肌无力型神经源性膀胱患者按照随机数字表法分为常规治疗组、“三调针法”治疗组、rFMS治疗组和综合治疗组,每组30例。常规治疗组给予常规康复治疗,“三调针法”治疗组在常规康复治疗的基础上予“三调针法”治疗(调神、调反射弧、调下焦和水道),rFMS治疗组在常规康复治疗的基础上予rFMS治疗,综合治疗组在常规康复治疗的基础上予“三调针法”和rFMS治疗。比较治疗前后各组患者初始尿意容量(FDV)、最大膀胱测量容量(MCC)、储尿期最大逼尿肌压(***)、储尿期最大膀胱内压(***)、日均排尿次数、日均漏尿次数、残余尿量、神经源性膀胱症状评分,评定各组临床疗效。结果与治疗前比较,4组患者治疗后FDV、MCC、***均升高,***、日均排尿次数、日均漏尿次数、残余尿量、神经源性膀胱症状评分均降低(均P<0.05)。治疗后,与常规治疗组比较,“三调针法”治疗组、rFMS治疗组、综合治疗组FDV、MCC、***均升高,***、日均排尿次数、日均漏尿次数、残余尿量、神经源性膀胱症状评分均降低(均P<0.05)。治疗后,与“三调针法”治疗组、rFMS治疗组比较,综合治疗组FDV、MCC、***均升高,***、日均排尿次数、日均漏尿次数、残余尿量、神经源性膀胱症状评分均降低(均P<0.05)。“三调针法”治疗组愈显率为86.2%(25/29),rFMS治疗组愈显率为85.7%(24/28),综合治疗组愈显率为92.6%(25/27),均高于常规治疗组的75.9%(22/29)。结论“三调针法”、rFMS均能有效改善脊髓损伤后逼尿肌无力型神经源性膀胱患者膀胱功能状态,二者联合应用具有协同增效作用。

关键词：三调针法重复功能性磁刺激脊髓损伤逼尿肌无力型神经源性膀胱

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

Switchable chiral mirror based on PIN diodes

引用

光子学研究:英文版 2023年第7期11卷 1154-1161页

作者： ZHIBIAO ZHU ZHE QIN HE WANG LIXIN JIANG YONGFENG LI WENJIE WANG HONGYA CHEN JIAFU WANG yongqiang pang SHAOBO QU Shaanxi Key Laboratory of Artificially-Structured Functional Materials and Devices Air Force Engineering UniversityXi’an 710051China School of Electronic Science and Engineering Xi’an Jiaotong UniversityXi’an 710049China

Chiral mirrors can produce spin selective absorption for left-handed circularly polarized(LCP) or right-handed circularly polarized(RCP) waves. However, the previously proposed chiral mirror only absorbs the designated circularly polarized(CP) wave in the microwave frequency band, lacking versatility in practical ***, we propose a switchable chiral mirror based on a pair of PIN diodes. The switchable chiral mirror has four working states, switching from the handedness-preserving mirror to the LCP mirror, RCP mirror, and perfect absorber. The basis of these advances is to change the chirality of two-dimensional(2D) chiral metamaterials and the circular conversion dichroism related to it, which is the first report in the microwave frequency *** current distributions shed light on how switchable chiral mirrors work by handedness-selective excitation of reflective and absorbing electric dipole modes. Energy loss distributions verify the working mechanism. The thickness of the switchable chiral mirror is one-tenth of the working wavelength, which is suitable for integrated manufacturing. The measurement results are in good agreement with the simulation results.

关键词： mechanism mirror chiral

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

Optical transparent infrared high absorption metamaterial absorbers

引用

Journal of Advanced Dielectrics 2018年第1期8卷 56-63页

作者： Jingfan Yang Cuilian Xu Shaobo Qu Hua Ma Jiafu Wang yongqiang pang College of Science Air Force Engineering University Xi’an 710051P.R.China

In this work,an optical transparent infrared high absorption metamaterial absorber is proposed based on indium tin oxide(ITO)*** to the fact that ITO holds high reflectivity property in infrared region while transparent in optical region,ITO can be used in the application of Surface Plasmon *** this design,three kinds of infrared metamaterial absorbers were *** of them can achieve high absorption at 10.6μm while remaining transparent in visible *** equivalent circuit model was served as design *** infrared absorption efficiency was numerically calculated and the mechanism analysis is given in the *** simulation results show that all three structures can achieve high absorption efficiency at 10.6μm under TE/TM *** absorption remains high when the incident angle is less than 70°.Experimental results exhibit good accordance with simulation.

关键词： ITO infrared metamaterial absorber visible transparent insensitive 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

A reflective-backing-free metamaterial absorber with broadband response

引用

Journal of Advanced Dielectrics 2017年第3期7卷 9-13页

作者： Cuilian Xu Shaobo Qu Jiafu Wang Mingbao Yan yongqiang pang Wenjie Wang Hua Ma Science College Air Force Engineering University Xi'an 710051P.R.China

In this paper,we propose a polarization-independent and broadband perfect infrared(IR)metamaterial absorber(MA)without reflective *** proposed absorber is a periodic meta-atom array consisting of metal-dielectric-multilayer truncated cones which can absorb 80%EM wave from 50.70 to 81.87 THz,while transmit 80%EM wave from 0 to 37.71 *** the decreasing of frequency,the transmissivity increases,which is close to 100%from 0 to 5 *** can broaden the absorption bandwidth of the MA by cascading multi-layers truncated ***,the proposed IR MA promises to be one desirable stealth material for radar-IR compatibility.

关键词： Metamaterial absorber reflective-backing-free infrared-radar stealth-compatible.

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

Shape memory alloy-based 3D morphologically reconfigurable chiral metamaterial for tailoring circular dichroism by voltage control

引用

Photonics Research 2023年第3期11卷 373-382页

作者： LIXIN JIANG QI YUAN HAO YANG YONGFENG LI LIN ZHENG ZHIBIAO ZHU SHUANG LIANG yongqiang pang HE WANG JIAFU WANG SHAOBO QU Shaanxi Key Laboratory of Artificially-Structured Functional Materials and Devices Airforce Engineering UniversityXi'an 710051China Electronic Materials Research Laboratory Key Laboratory of the Ministry of EducationXi'an Jiaotong UniversityXi'an 710049China

Three-dimensional chiral materials with intrinsic chirality play a crucial role in achieving a strong chiral response and flexible light *** chirality through the 3D morphological transformation of chiral materials is significant for greater freedom in tailoring light but remains a *** by the unique 3D morphological memory capability of shape memory alloys(SMAs),we demonstrate and discuss a chiral resonator in the microwave regime that can realize reconfigurable chirality through 3D morphological *** introduction of heating film realizes voltage control of SMA’s morphology for utilizing the temperature sensitivity of SMA better,enabling arbitrary control of circular dichroism(CD)flip and CD *** qualitative and quantitative analysis of the surface current distribution of chiral enantiomers reveals that the chirality of metaatoms originates from the surge of electric dipole pxand electric quadrupole *** is worth mentioning that the proposed strategy to achieve reconfigurable chirality using 3D morphological transformations can be directly extended to other higher frequencies,such as visible,infrared,and terahertz ***,our paradigm to study the relationship between complex 3D morphology and chirality holds potential for application in biosensing,spin detection,and spin-selective devices.

关键词： chiral circular holds

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：