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Wideband diffusion metabsorber for perfect scattering field reduction

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Photonics Research 2022年第6期10卷 1361-1366页

作者： ZICHENG SONG pingping min JIAQI ZHU LEI YANG FENG HAN LIN Center for Composite Materials and Structures Harbin Institute of TechnologyHarbin 150080China School of Information Science and Technology ShanghaiTech UniversityShanghai 201210China Research Center of Analysis and Measurement Harbin Institute of TechnologyHarbin 150080China

Both absorption and diffuse reflection can effectively suppress microwave backward ***,the challenge of designing wideband absorptive elements with anti-phase reflection hinders the simultaneous working of the two *** aid of the wideband characteristic of bilateral complementary structure,we propose a strategy to design wideband absorptive elements with large reflection phase *** proof of concept,the proposed elements are arranged in a rectangular grid by optimizing scattering field *** proposed diffusion metabsorber achieves over 20-dB scattering field reduction in the range of 8.5–20.3 GHz with good polarization stability and high angular insensitivity of up to±40°,which has been verified by real ***,the proposed design strategy exhibits the potential to further reduce electromagnetic wave reflection,and the optical transparent characteristic is promising for window applications.

关键词： scattering diffusion perfect

Design strategy of a high-performance multispectral stealth material based on the 3D meta-atom

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Photonics Research 2023年第11期11卷 1934-1944页

作者： pingping min ZICHENG SONG TIANYU WANG VICTOR GRALCHENKO YURONG HE JIAQI ZHU National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of TechnologyHarbin 150080China School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150080China Prokhorov General Physics Institute of Russian Academy of Sciences Moscow 119991Russia

In this paper,a 3D meta-atom-based structure is constructed for the multifunctional compatible design of visible,infrared,and *** achieve high performance,a novel dispersion tailoring strategy is *** the incorporation of multiple controllable losses within the 3D meta-atom,the dispersion characteristics are tailored to the desired target *** effectiveness of the strategy is verified with an error rate of less than5%.A proof-of-concept prototype is designed and fabricated,exhibiting high visible transparency,low infrared emission of 0.28,and microwave ultra-broadband absorption with a fractional bandwidth of 150%under 2.7 to18.7 *** work contributes a novel design strategy for the development of high-performance multispectral stealth materials with wide applications.

关键词： performance visible microwave

Gain deeper insights into traditional Chinese medicines using multidimensional chromatography combined with chemometric approaches

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Chinese Herbal Medicines 2024年第1期16卷 27-41页

作者： Xinyue Yang pingping Zeng Jin Wen Chuanlin Wang Liangyuan Yao min He Department of Pharmaceutical Engineering School of Chemical EngineeringXiangtan UniversityXiangtan 411105China Hunan Qianjin Xiangjiang Pharmaceutical Joint Stock Co. Ltd.Zhuzhou 412000China

Traditional Chinese medicines(TCMs)possess a rich historical background,unique theoretical framework,remarkable therapeutic efficacy,and abundant ***,the modernization and internationalization of TCMs have faced significant obstacles due to their diverse ingredients and unknown *** gain deeper insights into the phytochemicals and ensure the quality control of TCMs,there is an urgent need to enhance analytical ***,two-dimensional(2D)chromatography,which incorporates two independent separation mechanisms,demonstrates superior separation capabilities compared to the traditional one-dimensional(1D)separation system when analyzing TCMs *** the past decade,new techniques have been continuously developed to gain actionable insights from complex *** review presents the recent advancements in the application of multidimensional chromatography for the quality evaluation of TCMs,encompassing 2D-gas chromatography(GC),2D-liquid chromatography(LC),as well as emerging three-dimensional(3D)-GC,3D-LC,and their associated data-processing *** studies highlight the promising potential of multidimensional chromatographic separation for future phytochemical ***,the increased separation capability has resulted in higher-order data sets and greater demands for data-processing *** that multidimensional chromatography is still a relatively nascent research field,further hardware enhancements and the implementation of chemometric methods are necessary to foster its robust development.

关键词： chemometrics multidimensional separation off-line two-dimensional liquid chromatography on-line two-dimensional liquid chromatography quality control traditional chinese medicines two-dimensional gas chromatography

老年女性盆底功能障碍性疾病的症状和生活质量调查问卷的临床应用

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中华老年医学杂志 2024年第3期43卷 410-416页

作者：李萍萍李旻北京医院妇产科国家老年医学中心中国医学科学院老年医学研究院北京100730 中国医学科学院北京协和医学院研究生院北京100730

盆底功能障碍性疾病是由于盆底结构损伤和功能障碍而引起的一组临床综合征,主要包括盆腔器官脱垂、失禁以及盆腔痛等,该疾病在老年女性中患病率超过50%,疾病的症状和由此产生的精神心理疾病严重影响老年人的生活质量。因此,评价疾病症... 详细信息

盆底功能障碍性疾病是由于盆底结构损伤和功能障碍而引起的一组临床综合征,主要包括盆腔器官脱垂、失禁以及盆腔痛等,该疾病在老年女性中患病率超过50%,疾病的症状和由此产生的精神心理疾病严重影响老年人的生活质量。因此,评价疾病症状的严重程度和对生活质量的影响,对于老年女性盆底功能障碍性疾病的诊断和治疗至关重要。症状及生活质量调查问卷是评价老年女性盆底功能障碍性疾病严重程度和临床治疗效果的重要工具。但目前临床上相关问卷种类繁多,临床医生对老年女性盆底功能障碍性疾病调查问卷的选择、使用和评价常存在困惑。本文通过CiteSpace筛选出老年女性盆底功能障碍性疾病的研究热点及常用调查问卷,介绍症状及生活质量调查问卷的应用和评价方法,旨在提高临床医生对老年女性盆底功能障碍性疾病调查问卷的应用能力。

关键词：尿失禁问卷调查盆底功能障碍性疾病

油气资源开发区域生态承载力变化及发展能力评价——以大庆油田为例

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中国石油大学学报（社会科学版） 2021年第4期37卷 10-17页

作者：彭民闵萍萍朱志红东北石油大学石油经济与管理研究所黑龙江大庆163318 东北石油大学经济管理学院黑龙江大庆163318

为了解油气资源开发过程中的生态占用情况,利用生态足迹法,结合油气资源开发特点、对环境的影响及开发区域的自然情况,增加污染账户,来分析开发区域生态承载力变化趋势;利用生态压力、万元GDP生态足迹、生态足迹多样性和发展能力等指数... 详细信息

为了解油气资源开发过程中的生态占用情况,利用生态足迹法,结合油气资源开发特点、对环境的影响及开发区域的自然情况,增加污染账户,来分析开发区域生态承载力变化趋势;利用生态压力、万元GDP生态足迹、生态足迹多样性和发展能力等指数来评估该区域的可持续发展能力。以大庆油田为例,对1987—2017年的相关统计数据进行了测算,结果表明:近30年间大庆油田人均生态足迹明显高于人均生态承载力,生态赤字水平逐年升高,生态压力指数波动式增加,区域生态压力逐年增大,万元GDP生态足迹大幅下降后保持相对稳定,区域生态多样性与发展能力之间的差距在扩大。研究认为进入开发中后期阶段的油田,既面临地区生态供需矛盾突出的现实,又面临经济高质量转型升级的考验,需要采取均衡化、生态化、智慧化的策略,对油田土地进行综合开发与再利用。

关键词：油气资源生态足迹生态承载力发展能力

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基于TEM喇叭的电磁脉冲辐射天线优化设计

强激光与粒子束 2024年第4期36卷 89-95页

作者：周星芦艺兵赵敏王平平陆军工程大学石家庄校区电磁环境效应重点实验室石家庄050003

针对TEM喇叭天线终端反射大、低频辐射效率低的问题,对其进行了仿真优化设计。采用时域分析方法,分析了端部加载电阻与背部加载电阻的低频补偿方法,对TEM喇叭天线的尺寸、极板顶角等结构参数进行了优化,采用末端卷边结构,提升了辐射场... 详细信息

针对TEM喇叭天线终端反射大、低频辐射效率低的问题,对其进行了仿真优化设计。采用时域分析方法,分析了端部加载电阻与背部加载电阻的低频补偿方法,对TEM喇叭天线的尺寸、极板顶角等结构参数进行了优化,采用末端卷边结构,提升了辐射场的峰值场强与脉宽。根据仿真优化结果,研制了长度2.5 m、天线极板间张角45°、天线极板顶角45°的TEM喇叭天线,通过实测验证了仿真结果。结果表明,加载电阻可以有效降低反射,背部加载电阻方式的峰值场强和脉宽比端部加载电阻高,且采用4个电阻并联加载的效果较好;适当增加天线长度、极板顶角以及极板间夹角可以提高天线辐射性能。该研究结果为TEM喇叭天线在辐射式核电磁脉冲试验系统的应用提供了参考。

关键词： TEM喇叭天线核电磁脉冲天线尺寸优化加载电阻天线结构优化

颈动脉斑块报告和数据系统联合临床特征对脑卒中的预测价值

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中国超声医学杂志 2024年第9期40卷 961-963页

作者：乔敏陆萍萍沈德娟扬州大学附属苏北人民医院超声科

目的探讨颈动脉斑块报告和数据系统(Plaque-RADS)联合临床特征对脑卒中的预测价值。方法回顾性分析127例急性缺血性脑卒中患者及108例健康体检者的颈动脉超声及临床资料，根据Plaque-RADS进行分类，比较两组的Plaque-RADS及临床特征... 详细信息

目的探讨颈动脉斑块报告和数据系统(Plaque-RADS)联合临床特征对脑卒中的预测价值。方法回顾性分析127例急性缺血性脑卒中患者及108例健康体检者的颈动脉超声及临床资料，根据Plaque-RADS进行分类，比较两组的Plaque-RADS及临床特征，采用多因素Logistic回归分析建立回归模型，采用受试者工作特征(ROC)曲线评价Plaque-RADS联合临床特征对脑卒中的预测价值。结果两组高血压、糖尿病病史及Plaque-RADS分类差异有统计学意义(P<0.05)。多因素Logistic回归分析显示，高血压病史及Plaque-RADS分类是脑卒中的独立危险因素(P<0.05)。ROC曲线表明，Plaque-RADS联合临床特征对脑卒中的预测价值较高(曲线下面积=0.717,95%CI:0.652～0.782,P<0.001)。结论 Plaque-RADS联合临床特征对脑卒中有较好的预测价值。

关键词：颈动脉超声检查报告和数据系统脑卒中

Controllable time delay using slow/fast light in active fiber ring resonators with gain manipulation

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Science China(Physics,Mechanics & Astronomy) 2013年第6期56卷 1085-1089页

作者： XIAO pingping HU HongWu QI min College of Physics Science and Engineering Technology Yichun University College of Mathematics and Computer Science Yichun University

We propose to generate controllable time delay using slow/fast light in fiber ring resonators with gain *** dispersion and group delay of active fiber ring resonator can be controlled by manipulating its gain level below the lasing *** of the negative group delay in the undercoupled regime and the positive group delay in the overcoupled regime is theoretically ***,large group delay can be obtained accompanied by signal gain in active ring *** addition,we describe wide bandwidth and large group delay in 4-stage cascaded ring resonators.

关键词： slow and fast light fiber ring resonator loss factor active fiber

Well-dispersive K2O-KCl alkaline catalyst derived from waste banana peel for biodiesel synthesis

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Green Energy & Environment 2019年第3期4卷 322-327页

作者： mingming Fan Hao Wu min Shi Pingbo Zhang pingping Jiang The Key Laboratory of Food Colloids and Biotechnology Ministry of Education School of Chemical and Material Engineering Jiangnan University

In this work, a novel alkaline catalyst was synthesized by an economical and effective method of roasting waste banana peel. From XRD, FTIR, SEM, EDS, TGA and CO2-TPD characterization, it was proved that the calcined banana peel catalyst showed the strong alkalinity and well dispersity in microstructure, and K2O-KCl as the main active contents. The calcined banana peel catalyst showed better catalytic performance than the catalysts by physical mixing of K2O and KCl, which was due to good dispersibility of K2O-KCl formed during decomposing of carbon fiber by calcination of banana peel. Furthermore, the calcined banana peel catalyst also performed well in both water-resistant ability and recyclability, indicating their potential for biodiesel production from an efficient, robust, and low-cost catalyst.

关键词： Biodiesel Banana peel Basic catalyst Transesterification