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A low-frequency pure metal metamaterial absorber with continuously tunable stiffness

Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1209-1224页

作者： Xingzhong WANG Shiteng RUI shaokun yang Weiquan ZHANG Fuyin MA School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an710049China Xi’an Precision Machinery Research Institute Xi’an710077China

To address the incompatibility between high environmental adaptability and deep subwavelength characteristics in conventional local resonance metamaterials,and overcome the deficiencies in the stability of existing active control techniques for band gaps,this paper proposes a design method of pure metal vibration damping metamaterial with continuously tunable stiffness for wideband elastic wave *** design a dual-helix narrow-slit pure metal metamaterial unit,which possesses the triple advantage of high spatial compactness,low stiffness characteristics,and high structural stability,enabling the opening of elastic flexural band gaps in the low-frequency *** to the principle of a sliding rheostat,the introduction of continuously sliding plug-ins into the helical slits enables the continuous variation of the stiffness of the metamaterial unit,achieving a continuously tunable band gap *** successfully extends the effective band gap by more than ten *** experimental results indicate that this metamaterial unit can be used as an additional vibration absorber to absorb the low-frequency vibration energy ***,it advances the metamaterial absorbers from a purely passive narrowband design to a wideband tunable *** pure metal double-helix metamaterials retain the subwavelength properties of metamaterials and are suitable for deployment in harsh ***,by adjusting its stiffness,it substantially broadens the effective band gap range,presenting promising potential applications in various mechanical equipment operating under adverse conditions.

关键词： elastic metamaterial absorber continuously tunable stiffness low-frequency vibration damping variable stiffness design pure metal structure

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微波辅助顶空固相微萃取GC-MS法分析柠檬草中挥发性成分

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云南化工 2024年第2期51卷 93-99页

作者：杨玉贤张琼杨绍坤高云涛和顺琴云南医药健康职业学院云南昆明650033 云南民族大学云南昆明650500

设计制作了一种微型底聚焦微波反应装置,用于辅助顶空固相微萃取,解决了无溶剂顶空提取的问题,建立了柠檬草样品中挥发性成分的微波辅助顶空固相微萃取方法。使用GC-MS法对柠檬草叶片和根茎萃取物中挥发性成分进行分析鉴定,分别得到37... 详细信息

设计制作了一种微型底聚焦微波反应装置,用于辅助顶空固相微萃取,解决了无溶剂顶空提取的问题,建立了柠檬草样品中挥发性成分的微波辅助顶空固相微萃取方法。使用GC-MS法对柠檬草叶片和根茎萃取物中挥发性成分进行分析鉴定,分别得到37和46种化合物,结合峰面积归一法确定各组分的含量,其挥发性成分别占萃取物挥发总量的89.93%和77.29%。其中叶片和根茎中含量较高的挥发性成分都是橙花醛和香叶醛,叶片中的主要挥发性成分橙花醛(29.27%)和香叶醛(22.14%)的相对含量要明显优于根茎中橙花醛(8.61%)和香叶醛(7.76%)。研究为样品特别是固体样品挥发性成分的直接快速分析提供了一种稳定高效、简单快速的新方法,具有广泛的应用前景。

关键词：微型底聚焦微波反应器顶空固相微萃取气相色谱-质谱联用柠檬草挥发性成分

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The distribution of dimethylcarbazoles in oils from the Pearl River Mouth Basin, South China Sea

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Chinese Journal Of Geochemistry 2007年第3期26卷 301-304页

作者： ZHANG Chunming ZHAO Hongjing GAO Kunshun yang shaokun Key Laboratory of Exploration Technologies for Oil and Gas Resources （yangtze University） Ministry of Education Jingzhou 434023 China Department of Geochemistry Yangtze University Jingzhou 434023 China Bohai Oil Research Institute of Bohai Oil Production Technology ＆ Service Company Tianjin 300452 China China National Offshore Oil Corporation Beijing I00027 China

C2-carbazole isomers have been investigated in crude oils from the Hui-Liu Structure Ridge (HLSR) in the Pearl River Mouth Basin (PRMB), South China Sea. The NH shielded isomer, as well as the NH partially shielded isomers, was detected in high abundance and the NH exposed isomers in lower abundance. A small-enrichment trend of 1,8-dimethylcarbazole (DMC) was observed in crude oils along the western part of HLSR (WPHLSR), which may indicate little effect of migration on the C2-carbazole distributions. Two strikingly different distribution patterns of NH partially shielded isomers were observed in the reservoirs along the WPHLSR: one with a preference of 1,3- and 1,6-DMCs and the other with a preference of 1,4- and 1,5-DMCs. All of the oils occurring in the Upper reservoirs have a preference of 1,3- and 1,6-DMCs, whereas those trapped in the Lower reservoirs show a preference of 1,4- and 1,5-DMCs, which may indicate there are two petroleum migration systems in the WPHLSR.

关键词：石油氮化合物珠江流域南海

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盆底磁治疗中风后尿失禁的临床效果

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中国医药导报 2024年第6期21卷 138-141,146页

作者：刘际石胡国强杨少坤胡永红王阔阔石家庄市中医院康复科河北石家庄050051 石家庄市中医院东院区脑病二科河北石家庄050011

目的观察盆底磁治疗中风后尿失禁的临床效果。方法选取2022年9月至2023年6月就诊于石家庄市中医院康复科80例中风后尿失禁患者为观察对象,按照随机数字表法将其分为观察组(40例)与对照组(40例)。对照组予针刺治疗,观察组在对照组基础... 详细信息

目的观察盆底磁治疗中风后尿失禁的临床效果。方法选取2022年9月至2023年6月就诊于石家庄市中医院康复科80例中风后尿失禁患者为观察对象,按照随机数字表法将其分为观察组(40例)与对照组(40例)。对照组予针刺治疗,观察组在对照组基础上予盆底磁治疗。两组均为每日1次,治疗2周。比较两组治疗前后24 h排尿日记、尿失禁生活质量问卷(I-QOL)评分、尿失禁问卷简表(ICI-Q-SF)评分和尿动力学指标及治疗疗效。结果观察组脱落2例,对照组脱落1例。治疗后,两组24 h排尿次数、尿失禁次数、ICI-Q-SF评分和残余尿量均较治疗前减少,且观察组低于对照组,差异有统计学意义(P<0.05);两组I-QOL评分和最大膀胱容量均较治疗前增加,且观察组高于对照组,差异有统计学意义(P<0.05);观察组疗效优于对照组,差异有统计学意义(P<0.05)。结论针刺联合盆底磁治疗中风后尿失禁的效果优于针刺治疗,可明显改善患者膀胱功能,降低尿失禁发生次数,提升生活质量。

关键词：针刺盆底磁中风尿失禁

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面向联盟链转账隐私保护的^(+)HomElG零知识证明协议

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工程科学与技术 2023年第5期55卷 272-282页

作者：景旭杨少坤西北农林科技大学信息工程学院陕西杨凌712100

在联盟链转帐交易中,账本对联盟参与方是透明的,交易隐私保护是面临的最大挑战之一。针对联盟链隐私保护研究中保护账户余额、交易金额存在的交易合法性验证策略不完善、基础加密算法Paillier效率较低的问题,提出了一种面向联盟链转帐... 详细信息

在联盟链转帐交易中,账本对联盟参与方是透明的,交易隐私保护是面临的最大挑战之一。针对联盟链隐私保护研究中保护账户余额、交易金额存在的交易合法性验证策略不完善、基础加密算法Paillier效率较低的问题,提出了一种面向联盟链转帐隐私保护的^(+)HomElG零知识证明协议。基于PBFT构造了一种联盟链转账隐私保护应用,论述了同态加密的零知识证明的共识交互场景;通过^(+)HomElG算法加密交易金额及账户余额,根据Σ协议设计密文的零知识证明;通过Fiat-Shamir算法的思想,设计了非交互式零知识证明的相等性证明、范围证明中交易的金额大于零和转账方余额不小于零等过程,并在DDH安全前提下证明它们具有正确性、完备性、零知识性。基于Hyperledger Fabric构建了一个联盟链转账隐私保护原型系统,测试结果验证了该协议在非交互式零知识证明条件下能实现保护账户余额、交易金额的密文交易;当密钥长度为3072 bit,测试数据长度为12 bit的十进制整数时,^(+)HomElG算法的效率是150.3 ms,交易金额相等、交易金额大于零以及交易余额不小于零等零知识证明过程的效率(证据生成和验证)分别是482.3、209.3和261.3 ms。测试结果表明,与现有协议相比,该协议的^(+)HomElG算法的效率较高,相等性证明、范围证明等交易合法性验证策略更加完善和高效,满足联盟链转账交易隐私保护需求。

关键词：联盟链零知识证明隐私保护同态加密 +HomElG

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Impact of Blade-Flapping Vibration on Aerodynamic Characteristics of Wind Turbines under Yaw Conditions

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Energy Engineering 2024年第8期121卷 2213-2229页

作者： shaokun Liu Zhiying Gao Rina Su Mengmeng Yan Jianwen Wang College of Energy and Power Engineering Inner Mongolia University of TechnologyHohhot010051China Key Laboratory of Wind and Solar Energy Utilization Technology Ministry of EducationHohhot010051China

Although the aerodynamic loading of wind turbine blades under various conditions has been widely studied,the radial distribution of load along the blade under various yaw conditions and with blade flapping phenomena is poorly *** study aims to investigate the effects of second-order flapwise vibration on the mean and fluctuation characteristics of the torque and axial thrust of wind turbines under yaw conditions using computational fluid dynamics(CFD).In the CFD model,the blades are segmented radially to comprehensively analyze the distribution patterns of torque,axial load,and tangential *** following results are obtained.(i)After applying flapwise vibration,the torque and axial thrust of wind turbines decrease in relation to those of the rigid model,with significantly increased fluctuations.(ii)Flapwise vibration causes the blades to reciprocate along the axial direction,altering the local angle of attack and velocity of the blades relative to the incoming wind *** results in the contraction of the torque region from a circular shape to a complex“gear”shape,which is accompanied by evident oscillations.(iii)Compared to the tangential load,the axial load on the blades is more sensitive to flapwise vibration although both exhibit significantly enhanced *** study not only reveals the impact of flapwise vibration on wind turbine blade performance,including the reduction of torque and axial thrust and increased operational fluctuations,but also clarifies the radial distribution patterns of blade aerodynamic characteristics,which is of great significance for optimizing wind turbine blade design and reducing fatigue risks.

关键词： Wind turbine CFD numerical simulation aerodynamic characteristics yaw flapping vibration

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Coupling of reduced inorganic fertilizer with plant-based organic fertilizer as a promising fertilizer management strategy for colored rice in tropical regions

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Journal of Integrative Agriculture 2024年第1期23卷 93-107页

作者： Tingcheng Zhao Aibin He Mohammad Nauman Khan Qi Yin shaokun Song Lixiao Nie Research Center for Physiology and Ecology and Green Cultivation of Tropical Crops School of Breeding and Multiplication(Sanya Institute of Breeding and Multiplication)Hainan UniversitySanya 572000China

Colored rice is a type of high-quality,high-added-value rice that has attracted increasing attention in recent *** use of large amounts of inorganic nitrogen fertilizer in rice fields results in low fertilizer use efficiency and high environmental *** fertilizer is a promising way to improve soil quality and sustain high ***,most studies focus on the effect of animal-based organic *** effects of different ratios of plantbased organic fertilizer and inorganic fertilizer on the grain yield and quality of colored rice have rarely been ***,a two-year field experiment was conducted in 2020 and 2021 to study the effects of replacing inorganic N fertilizers with plant-based organic fertilizers on the yield,nitrogen use efficiency(NUE),and anthocyanin content of two colored rice varieties in a tropical region in *** experimental treatments included no nitrogen fertilization(T1),100% inorganic nitrogen fertilizer(T2),30%inorganic nitrogen fertilizer substitution with plant-based organic fertilizer(T3),60%inorganic nitrogen fertilizer substitution with plant-based organic fertilizer(T4),and 100% plantbased organic fertilizer(T5).The total nitrogen provided to all the treatments except T1 was the same at 120 kg *** results showed that the T3 treatment enhanced the grain yield and anthocyanin content of colored rice by increasing nitrogen use efficiency compared with *** average,grain yields were increased by 9 and 8%,while the anthocyanin content increased by 16 and 10% in the two colored rice varieties under T3 across the two years,respectively,as compared with *** study of the residual effect of partial substitution of inorganic fertilizers showed that the substitution of inorganic fertilizer with plant-based organic fertilizer improved the soil physiochemical properties,and thus increased the rice grain yield,in the subsequent *** highest grain yield of the subsequent rice crop was observe

关键词： colored rice organic fertilizer soil quality grain yield anthocyanin

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A Magnetic-Multiplier-Enabled Hybrid Generator with Frequency Division Operation and High Energy Utilization Efficiency

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Research 2024年第1期2023卷 561-570页

作者： Jie Chen Kangjie Wu shaokun Gong Jianchao Wang Ke Wang Hengyu Guo College of Physics and Electronic Engineering Chongqing Key Laboratory Photo-electric Functional MaterialsChongqing Normal UniversityChongqing 401331China State Key Laboratory of Mechanical Transmission College of Mechanical and Vehicle EngineeringChongqing UniversityChongqing 400044China School of Physics Chongqing UniversityChongqing 400044China

The hybrid electromagnetic-triboelectric generator(HETG)is a prevalent device for mechanical energy ***,the energy utilization efficiency of the electromagnetic generator(EMG)is inferior to that of the triboelectric nanogenerator(TENG)at low driving frequencies,which limits the overall efficacy of the *** tackle this issue,a layered hybrid generator consisting of a rotating disk TENG,a magnetic multiplier,and a coil panel is *** magnetic multiplier not only forms the EMG part with its high-speed rotor and the coil panel but also facilitates the EMG to operate at a higher frequency than the TENG through frequency division *** systematic parameter optimization of the hybrid generator reveals that the energy utilization efficiency of EMG can be elevated to that of rotating disk *** a power management circuit,the HETG assumes the responsibility for monitoring the water quality and fishing conditions by collecting low-frequency mechanical *** magneticmultiplier-enabled hybrid generator demonstrated in this work offers a universal frequency division approach to improve the overall outputs of any hybrid generator that collects rotational energy,expanding its practical applications in diverse multifunctional self-powered systems.

关键词： generator rotating assume

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冻融循环作用下城市污泥固化土长期力学性能

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应用基础与工程科学学报 2023年第1期31卷 65-80页

作者：杨爱武杨少坤王峥张先伟王亚成东华大学环境科学与工程学院上海201620 天津城建大学天津市软土特性与工程环境重点实验室天津300384 中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室湖北武汉430071

采用自主研发的新型固化剂对城市污泥进行固化处理,通过对污泥固化土进行冻融循环作用下的不固结不排水蠕变试验,探讨其在气候环境影响下的长期变形和强度发展特性.试验结果表明,污泥固化土抗剪强度随冻融循环次数的增加呈现先明显降低... 详细信息

采用自主研发的新型固化剂对城市污泥进行固化处理,通过对污泥固化土进行冻融循环作用下的不固结不排水蠕变试验,探讨其在气候环境影响下的长期变形和强度发展特性.试验结果表明,污泥固化土抗剪强度随冻融循环次数的增加呈现先明显降低后趋于稳定的趋势.当施加偏应力小于污泥固化土结构屈服应力时,其蠕变历时曲线呈现衰减型蠕变形态,各级应力水平下的曲线整体态势相近;当偏应力水平达到破坏应力时,蠕变变形急剧增长.在其他条件相同的情况下,冻融温度越低,蠕变变形的速率越快,每级蠕变稳定时的变形量也越大.污泥固化土等时曲线具有显著的屈服点,t=0h时刻等时曲线与其他时刻曲线簇相比存在明显的离散现象,在此基础上,基于应力⁃应变对数曲线和等时曲线拐点法,先后建立了能够考虑冻融循环作用影响的污泥固化土蠕变模型及其长期强度预测公式,可为相关工程实践提供参考.

关键词：污泥固化土冻融循环蠕变变形历时曲线等时曲线长期强度

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带落角约束的多导弹分布式协同制导律

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中国惯性技术学报 2018年第4期26卷 546-553页

作者：赵久奋史绍琨崇阳马峰尤浩火箭军工程大学西安710025

为实现多枚导弹协同攻击机动目标,基于具有推力可控能力的导弹,提出了一种带落角约束的多导弹分布式协同制导律。将制导律的设计分离为视线方向和视线法向上两个部分:视线方向上基于多智能体协同控制理论和超螺旋控制算法,设计制导律控... 详细信息

为实现多枚导弹协同攻击机动目标,基于具有推力可控能力的导弹,提出了一种带落角约束的多导弹分布式协同制导律。将制导律的设计分离为视线方向和视线法向上两个部分:视线方向上基于多智能体协同控制理论和超螺旋控制算法,设计制导律控制导弹剩余时间在有限时间内趋于一致;视线法向上运用零化视线角速率思想和有限时间滑模控制理论,设计制导律控制导弹击中目标的同时满足落角约束。并针对两部分制导律中存在的目标机动信息,分别设计非齐次干扰观测器进行估计。仿真结果表明,提出的制导律能够有效完成协同攻击任务,脱靶量和落角误差分别控制在0.13 m和0.02°以内,并且有效抑制了抖振现象,有利于提高导弹自动驾驶仪的跟踪精度。

关键词：协同制导落角约束机动目标分布式通信拓扑滑模控制抖振

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