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Observer-based H_∞ control over packet dropping networks 被引量:1
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作者 Zhang Dongmei Wang Xingang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2008年第6期1215-1225,共11页
A new controller design problem of networked control systems with packet dropping is proposed. Depending on the place that the observer is put in the system, the network control systems with packet dropping are modele... A new controller design problem of networked control systems with packet dropping is proposed. Depending on the place that the observer is put in the system, the network control systems with packet dropping are modeled as stochastic systems with the random variables satisfying the Bernoulli random binary distribution. The observer-based controller is designed to stabilize the networked system in the sense of mean square, and the prescribed H∞ disturbance attenuation level is achieved. The controller design problem is formulated as the feasibility of the convex optimization problem, which can be solved by a linear matrix inequality (LMI) approach. Numerical examples illustrate the effectiveness of the proposed methods. 展开更多
关键词 networked control systems packet dropping linear matrix inequality
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Effect of Instant Controlled Pressure Drop Process Coupled to Drying and Freezing on Antioxidant Activity of Green “Poblano” Pepper (<i>Capsicum annuum</i>L.)
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作者 Carmen Téllez-Pérez Anaberta Cardador-Martínez +3 位作者 Sabah Mounir José Gerardo Montejano-Gaitán Vaclav Sobolik Karim Allaf 《Food and Nutrition Sciences》 2013年第3期321-334,共14页
Different food operations have been intensified through assisting them by instant controlled pressure drop DIC treatment. Such processes should be defined in order to preserve the main nutritional and sensorial conten... Different food operations have been intensified through assisting them by instant controlled pressure drop DIC treatment. Such processes should be defined in order to preserve the main nutritional and sensorial contents of the raw material. The present paper is dedicated to study the evolution of the main bioactive compounds (total phenolics and flavonoids) and functional properties such as the antioxidant activity of processed samples in the case of Green “Poblano” Pepper (Capsicum annuum L.). Results issued from DIC-assisted hot air drying, and DIC-assisted freezing, allowed to identifying the impact of DIC studied operating parameters, which were the saturated steam pressure and the processing time, and the best DIC treatment correlated with the considered operation. 展开更多
关键词 Instant controlled Pressure drop CAPSICUM Phenols Flavonoids Antioxidant Activity DRYING FREEZING
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Towards Include Preservation of Vitamins in Fenugreek and Carob Seeds by the Instant Controlled Pressure-Drop Process (DIC Process)
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作者 Dalel Melki Lassaad Hedhili +3 位作者 Lamia Hamrouni Mohamed Negm Bassem Jamoussi Karim Allaf 《Food and Nutrition Sciences》 2018年第3期191-207,共17页
Fenugreek and carob seed were germinated in the dark for 4 days and 15 days respectively. The two species are rich in vitamins A, B1, B3, B8. Germination promotes the increase in their concentrations. To ensure preser... Fenugreek and carob seed were germinated in the dark for 4 days and 15 days respectively. The two species are rich in vitamins A, B1, B3, B8. Germination promotes the increase in their concentrations. To ensure preservation and increased bioavailability of the vitamins, it is necessary to apply a DIC of 30s to 400 kPa making it possible to support the cellular expansion and the decontamination of germinated seeds. Vitamin A content in germinated carob seed increased by 82.54%, which is not the case for fenugreek. A decrease in vitamin A concentration of 4 μg/100 g of dry matter. DIC increase vitamin B1, B3 and B8 in germinated fenugreek seeds. A slight decrease of B vitamins in germinated carob seed after treatment with DIC has been noticed. This loss can be explained by the low bioavailability caused mainly by the botanical structures of the seeds. 展开更多
关键词 FENUGREEK CAROB Seed Germination PRESERVATION Bioavailability Vitamin INSTANT controlled Pressure drop (DIC)
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基于图论的光伏系统多功率模块优化控制策略
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作者 王艳敏 宁佳铭 +1 位作者 张伟琦 王小永 《华中科技大学学报(自然科学版)》 北大核心 2026年第1期14-20,共7页
针对光伏系统多功率模块存在的功率分配不均、母线电压易扰动等问题,基于图论设计一种光伏系统多功率模块优化控制策略,改善了传统下垂控制对多分支光伏系统调控的局限性.首先基于图论中的跟踪同步和协调同步理论构建一致性算法并设计... 针对光伏系统多功率模块存在的功率分配不均、母线电压易扰动等问题,基于图论设计一种光伏系统多功率模块优化控制策略,改善了传统下垂控制对多分支光伏系统调控的局限性.首先基于图论中的跟踪同步和协调同步理论构建一致性算法并设计光伏系统二次优化控制器;然后利用李雅普诺夫函数证明了所设计控制器的有限时间收敛稳定性;最后以3台容量相同的功率模块并联运行为例,进行仿真分析和实验验证.实验结果表明:所提优化控制策略能够使光伏系统直流母线侧电压在负载变化时快速恢复到额定值±5%的误差范围内(较传统下垂控制提速3倍),且具有更小的尖峰,相比传统下垂控制策略使各功率模块的输出电流偏差极大的降低(小于2%),有效实现了系统各功率模块的均衡分配. 展开更多
关键词 光伏系统 图论 优化下垂控制策略 李雅普洛夫函数 功率分配
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考虑抑制二次跌落的风电自适应频率支撑控制策略及其参数整定
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作者 张超 文云峰 +2 位作者 黎婧娴 廖帮昆 孙铭锐 《电工技术学报》 北大核心 2026年第5期1510-1525,共16页
风资源的起伏致使风电在不同场景下对系统的频率支撑能力有所差异,而风电的频率支撑能力、控制策略及控制参数的不匹配将严重影响系统频率的动态响应。为提升风电参与频率支撑时的稳定性与持续性,该文首先提出一种考虑转速平滑恢复的风... 风资源的起伏致使风电在不同场景下对系统的频率支撑能力有所差异,而风电的频率支撑能力、控制策略及控制参数的不匹配将严重影响系统频率的动态响应。为提升风电参与频率支撑时的稳定性与持续性,该文首先提出一种考虑转速平滑恢复的风机频率支撑控制策略,使风机在系统频率到达最低点之后自适应地减小有功功率输出,使其进入转速恢复状态,同时根据转速恢复情况自适应地减小频率支撑控制参数,抑制了转速恢复对系统频率的不利影响;其次,依据风机参与频率支撑期间的运行点偏移,求得不同转速下风机的最小动能损耗,进而求出风机的最大频率支撑能量;然后推导出了计及同步机与风电参与频率支撑的系统频率动态响应模型的时域表达式,统一了不同阻尼比下的频率极值点计算式;随后,基于系统频率安全约束与风机频率支撑能量约束,建立了分别以风机频率支撑量和风机偏移量最小为目标的优化模型,实现了故障场景下各风电场控制参数的整定;最后通过IEEE 30节点系统和实际电网的仿真算例验证了所提方法的有效性。 展开更多
关键词 风电场 频率支撑控制 参数整定 转速恢复 二次跌落
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六辊CVC冷轧机冷轧硅钢边降机理及极限工况仿真研究
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作者 王小平 杨尚 +1 位作者 付超 杨庭松 《包钢科技》 2026年第1期7-15,共9页
冷轧带钢边降直接影响产品宽度精度和边部质量,在宽规格无取向硅钢及极限压下条件下尤为突出。依托1780 mm六辊CVC轧机,文章建立了轧辊-带钢耦合的一体化三维有限元模型,该模型在几何建模、边部及辊间接触区网格加密、边界约束与摩擦接... 冷轧带钢边降直接影响产品宽度精度和边部质量,在宽规格无取向硅钢及极限压下条件下尤为突出。依托1780 mm六辊CVC轧机,文章建立了轧辊-带钢耦合的一体化三维有限元模型,该模型在几何建模、边部及辊间接触区网格加密、边界约束与摩擦接触设定以及多步载荷增量控制等方面进行了优化,经与机组实测断面轮廓对比,仿真结果的RMSE为6.85μm、MAPE为1.26%,表明模型具有较高的预测精度。系统分析了带钢厚度、宽度、压下率及材料变形抗力对边降形成规律的影响,厚度增加或压下率升高会显著放大边部横向金属流动,加剧边降;增大带钢宽度可减小单位宽度上的横向流动,在一定程度上减弱边降;提高变形抗力则有利于抑制边部金属流动,降低边降及其对压下率的敏感性。在此基础上构建极限工况仿真体系,考察工作辊弯辊力、中间辊弯辊力及中间辊窜辊量对边降的综合调控能力。结果表明,工作辊弯辊对边降的调控最为显著,平均调控功效约为中间辊弯辊的3.5倍,中间辊窜辊在正负极限位置下可实现约30μm的线性调节幅度。通过引入边降调控功效系数,对不同调控手段的效率与灵敏度进行了量化评价,可为六辊CVC轧机辊形优化设计及宽规格硅钢边降控制工艺制定提供理论依据和工程参考。 展开更多
关键词 六辊CVC轧机 边降调控 有限元仿真 弯辊 窜辊
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Transverse thickness difference control technology for non-oriented silicon steel
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作者 LI Hongmei LI Shanqing +4 位作者 WANG Bo ZENG Jianfeng JIN Guo DUAN Mingnan ZHOU Yi 《Baosteel Technical Research》 CAS 2013年第1期20-23,共4页
Transverse thickness difference is an important quality index of non-oriented silicon steel strips. In order to fulfill users' accuracy requirements on the transverse thickness of silicon steel and improve the produc... Transverse thickness difference is an important quality index of non-oriented silicon steel strips. In order to fulfill users' accuracy requirements on the transverse thickness of silicon steel and improve the production yield, the factors influencing transverse thickness difference were analyzed. Then the work roll shape, control strategy and incoming hot-rolled strips were optimized. Since the optimization measures were implemented in the actual production, the thickness difference of non-oriented silicon steel has been reduced greatly and fulfilled the requirements placed by users. These measures have achieved remarkable effects. 展开更多
关键词 cold rolling transverse thickness difference non-oriented silicon steel roll shape edge drop control strategy
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0.01%浓度阿托品滴眼液在儿童青少年近视防控中应用进展
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作者 曾令根 刘琳琳 《医学研究前沿》 2026年第2期90-92,共3页
近视是一个全球性的公共卫生问题,随着近视的发展,高度近视可引起眼底出现病理性改变,甚至于致盲。近年来近视呈现出低龄化趋势,在近视发展早期进行治疗至关重要。低浓度阿托品已被证实在近视防控中安全有效且副作用小。本文对0.01%浓... 近视是一个全球性的公共卫生问题,随着近视的发展,高度近视可引起眼底出现病理性改变,甚至于致盲。近年来近视呈现出低龄化趋势,在近视发展早期进行治疗至关重要。低浓度阿托品已被证实在近视防控中安全有效且副作用小。本文对0.01%浓度阿托品滴眼液在治疗近视中应用的研究进展做一综述。 展开更多
关键词 阿托品滴眼液 近视防控 0.01%浓度 青少年
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基于VAE-GRU的风电逐步惯性控制二次频率跌落抑制方法
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作者 陈俊全 杨福 +3 位作者 蒲清昕 陈以欣 安甦 马覃峰 《黑龙江科技大学学报》 2026年第1期129-137,共9页
为提升高风电渗透率电网的频率稳定性与逐步惯性控制SIC参数自适应性,针对功率恢复阶段二次频率跌落的核心问题,采用变分自编码器与门控循环单元融合架构,提出一种结合灰狼优化算法样本生成、变分自编码器非线性特征提取与降噪、门控循... 为提升高风电渗透率电网的频率稳定性与逐步惯性控制SIC参数自适应性,针对功率恢复阶段二次频率跌落的核心问题,采用变分自编码器与门控循环单元融合架构,提出一种结合灰狼优化算法样本生成、变分自编码器非线性特征提取与降噪、门控循环单元动态映射建模的风电调频优化控制方法。通过改进IEEE39节点系统构建仿真模型,验证所提方法的抑制效果与鲁棒性。结果表明:相较于传统智能方法,文中方法控制参数预测的关键误差指标最大降低53.3%,在5~25 d B噪声环境下综合性能指标稳定高于0.85,25%数据缺失场景下仍保持0.7以上评分,系统频率二次跌落幅度显著减小,为高比例风电并网系统提供了兼具自适应与抗干扰能力的调频解决方案。 展开更多
关键词 风电渗透率 逐步惯性控制 二次频率跌落 变分自编码器 门控循环单元
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含构网型直驱风机的电力系统暂态功角稳定性分析与控制策略 被引量:1
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作者 韩平平 熊瑶 +2 位作者 吴红斌 陈鹏飞 董玮 《电力自动化设备》 北大核心 2025年第9期70-78,共9页
随着新型电力系统的发展,构网型直驱风机(GFM-PMSG)的应用更加广泛,但也改变了电力系统的功角稳定特性。为此,基于扩展等面积法(EEAC),分析了含GFM-PMSG的电力系统的暂态稳定性机理,并提出了一种适用于多机系统的改进GFM-PMSG暂态控制... 随着新型电力系统的发展,构网型直驱风机(GFM-PMSG)的应用更加广泛,但也改变了电力系统的功角稳定特性。为此,基于扩展等面积法(EEAC),分析了含GFM-PMSG的电力系统的暂态稳定性机理,并提出了一种适用于多机系统的改进GFM-PMSG暂态控制策略。构建了含风机的双机系统等效转子运动方程,得到风机并网对同步机之间功角特性的影响主要取决于其有功外特性的结论,并考虑多时间尺度特性,分析了GFM-PMSG的有功外特性;基于EEAC分析了考虑阻尼系数时GFM-PMSG接入对系统同步机之间功角稳定性的影响机理、GFM-PMSG和同步机之间的暂态功角稳定机理及控制参数的影响;提出了一种改进的GFMPMSG暂态控制策略,改善了含GFM-PMSG的电力系统的暂态功角稳定性;在PSCAD/EMTDC中搭建扩展双机系统仿真模型进行对比分析,验证所提策略的有效性。 展开更多
关键词 暂态功角稳定性 构网型直驱风机 电力系统 EEAC 电网电压跌落 暂态控制策略
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Rectangular Section Control Technology for Silicon Steel Rolling 被引量:5
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作者 Xiao-chen WANG Quan YANG You-zhao SUN 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2015年第3期185-191,共7页
Rectangular section control technology (RSCT) was introduced to achieve high-precision profile control during silicon steel rolling. The RSCT principle and method were designed, and the whole RSCT control strategy w... Rectangular section control technology (RSCT) was introduced to achieve high-precision profile control during silicon steel rolling. The RSCT principle and method were designed, and the whole RSCT control strategy was developed. Specifically, RSCT included roll contour design, roiling technology optimization, and control strategy development, aiming at both hot strip mills (HSMs) and cold strip mills (CSMs). Firstly, through the high-performance variable crown (HVC) work roll optimization design in the upper-stream stands and the limited shifting technology for schedule-free rolling in the downstream stands of HSMs, a hot strip with a stable crown and limited wedge, :local spot, and single wave was obtained, which was suitable for cold rolling. Secondly, an approximately rectangular section was obtained by edge varying contact (EVC) work roll contour design, edge-drop setting control, and. closed loop control in the upper-stream, stands of CSMs. Moreover, complex-mode flatness control was realized by coordinating multiple shape-control methods in the downstream stands of CSMs. In addition, the RSCT approach was applied in several silicon-steel production plants, where an outsicanding performance and remarkable economic benefits were observed. 展开更多
关键词 silicon steel rectangular section control technology hot rolling cold rolling edge drop
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Adaptive Terminal-Modality-Based Joint Call Admission Control for Heterogeneous Cellular Networks 被引量:1
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作者 Mahmoud M. Badawy Salman A. AlQahtani 《International Journal of Communications, Network and System Sciences》 2013年第9期395-406,共12页
The coexistence of different Radio Access Technologies (RATs) requires a need for Common Radio Resource Management (CRRM) to support the provision of Quality of Service (QoS) and the efficient utilization of radio res... The coexistence of different Radio Access Technologies (RATs) requires a need for Common Radio Resource Management (CRRM) to support the provision of Quality of Service (QoS) and the efficient utilization of radio resources. The provision of QoS is an important and challenging issue in the design of integrated services packet networks. Call admission control (CAC) is an integral part of the problem. Clearly, without CAC, providing QoS guarantees will be impossible. There is unfairness in allocation of radio resources among heterogeneous mobile terminals in heterogeneous wireless networks. In this paper, an Adaptive-Terminal Modality-Based Joint Call Admission Control (ATJCAC) algorithm is proposed to enhance connection-level QoS and reduce call blocking/dropping probability. The proposed ATJCAC algorithm makes call admission decisions based on mobile terminal modality (capability), network load, adaptive the bandwidth of ongoing call and radio access technology (RAT) terminal support index. Simulation results show that the proposed ATJCAC scheme reduces call blocking/dropping probability. 展开更多
关键词 CALL ADMISSION control CALL BLOCKING CALL dropPING Next Generation Wireless Network (NGWN) RAT Selection Approaches
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不同频次0.01%阿托品滴眼液控制青少年近视对眼表的影响 被引量:1
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作者 许琦彬 李秋实 +1 位作者 魏佳敏 戴红梅 《中国临床药理学与治疗学》 北大核心 2025年第2期238-243,共6页
目的:评估不同频次0.01%阿托品滴眼液控制青少年近视对眼表的影响。方法:本研究共招募84名青少年近视患者。随机分配入组予以不同频次(早起组、晚睡组、早晚组)0.01%阿托品滴眼液治疗,观察治疗期间眼部和全身不良反应,并在治疗前和治疗... 目的:评估不同频次0.01%阿托品滴眼液控制青少年近视对眼表的影响。方法:本研究共招募84名青少年近视患者。随机分配入组予以不同频次(早起组、晚睡组、早晚组)0.01%阿托品滴眼液治疗,观察治疗期间眼部和全身不良反应,并在治疗前和治疗后6个月,检查等效球镜度数(SER)、眼轴(AX),通过眼表疾病指数(OSDI)问卷、Keratograph 5M测量泪河高度(TMH)、非侵入式首次泪膜破裂时间(NifBUT)、非侵入性平均泪膜破裂时间(NiaBUT)、睑板腺萎缩评分(MaS)。结果:0.01%阿托品滴眼液治疗6个月内,所有不良反应症状均较轻微且很少发生。只有1例有全身反应,在给药后出现暂时性口干;有6名患者在给药后有眼痒、眼干等不适;早起组和早起晚睡组出现的眼部反应畏光、看近模糊较晚睡组多,但三组之间无统计学差异(P>0.05)。与治疗前相比,三组治疗6个月后,SER、AX有统计学差异(P<0.05);早起组患者OSDI评分(P=0.656)、TMH值(P=0.362)、NifBUT(P=0.510)、NiaBUT(P=0.700)、MaS(P=0.846)均未发生显著变化;晚睡组患者OSDI评分(P=0.429)、TMH值(P=0.462)、NifBUT(P=0.462)、NiaBUT(P=0.598)、MaS(P=0.351)均未发生显著变化;早晚组患者OSDI评分(P=0.457)、TMH值(P=0.748)、NifBUT(P=0.197)、NiaBUT(P=0.070)、MaS(P=0.802)均未发生显著变化。结论:不同频次0.01%阿托品滴眼液控制青少年近视6个月后,眼表无显著影响。 展开更多
关键词 0.01%阿托品滴眼液 眼表 青少年 近视控制
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On Line Measurement of Reactivity Worth of TRIGA Mark-II Research Reactor Control Rods
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作者 Nusrat Jahan Mamunur M. Rashid +3 位作者 F. Ahmed M. G. S. Islam M. Aliuzzaman S. M. A. Islam 《Journal of Modern Physics》 2011年第9期1024-1029,共6页
The reactivity worth measurement system for control rods of the TRIGA MARK-II research reactor of Bangladesh has been design and developed. The theory of the kinetic technique of measuring reactivity has been used by ... The reactivity worth measurement system for control rods of the TRIGA MARK-II research reactor of Bangladesh has been design and developed. The theory of the kinetic technique of measuring reactivity has been used by this measurement system. The system comprises of indigenous hardware and software for online acquisition of neutron flux signals from reactor console and then computes the reactivity worth accordingly. Here for the TRIGA MARK-II research reactor, the reactivity measurement system was implemented with a dedicated circuit assembly and a conventional personal computer. A high-level Visual Basic real-time programming has been developed for data acquisition, reactivity calculation, online display (numerically as well as graphically), saving data, etc. To measure reactivity worth of TRIGA reactor control rods the rod drop experimental technique has been adopted. The results of tests experiments, carried out with the rod drop method for measuring various reactivity worth of control rods have been presented in the paper. A comparison between this results with the results using period method and that of computation method, demonstrated that the response of this reactivity measurement system is fast enough to monitor and measure the safety-related reactivity and power excursions in the reactor. 展开更多
关键词 REACTIVITY WORTH Measurement control ROD Kinetic ROD drop Visual Basic
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耦合磁流变与液压机器人关节设计及冲击抑制
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作者 杨坤全 马佰周 +1 位作者 余春梅 黄惠 《机械设计与制造》 北大核心 2025年第8期332-339,349,共9页
液压机器人足端与地面接触时容易产生较大的碰撞冲击,其会导致零部件受损,严重影响足式机器人使用寿命。针对于此,这里提出了将磁流变阻尼器串联于液压驱动关节实现一体化的减振新方法。首先,以足端可达面积最大为目标,对液压足式机器... 液压机器人足端与地面接触时容易产生较大的碰撞冲击,其会导致零部件受损,严重影响足式机器人使用寿命。针对于此,这里提出了将磁流变阻尼器串联于液压驱动关节实现一体化的减振新方法。首先,以足端可达面积最大为目标,对液压足式机器人腿部结构进行优化,确定腿节长度、摆角及驱动器尺寸。其次,依据垂落工况设计磁流变阻尼器,并将其通过共用活塞杆的方式与液压作动器串联共同形成液压阻尼作动器。然后,依据单腿垂落冲击工况设计模糊控制器,进而减少冲击后的活塞杆位移误差。最后,通过单腿垂落冲击试验知:串有磁流变阻尼器的液压作动器对足式机器人具有明显的抗冲击效果,致使机械腿动态误差最小。 展开更多
关键词 液压足式机器人 磁流变阻尼器 液压阻尼作动器 垂落冲击 模糊控制器
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Control Rod Calibration and Worth Calculation for Optimized Power Reactor 1000 (OPR-1000) Using Core Simulator OPR1000 被引量:1
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作者 Nguyen An Son Nguyen Duc Hoa +2 位作者 Tran Trung Nguyen Tran Quoc Tuan Osvaldo Camueje Raul 《World Journal of Nuclear Science and Technology》 2017年第1期15-23,共9页
Control rod is used to change the power in nuclear reactor.?Certainly, the core at any moment can be made subcritical condition and shut downs when occurring?to emergency instance in the core. The rod is grouped based... Control rod is used to change the power in nuclear reactor.?Certainly, the core at any moment can be made subcritical condition and shut downs when occurring?to emergency instance in the core. The rod is grouped based?on their function and located at different places in the core where their feature is maximized.?Two methods of control rod calibration are the asymptotic period method and the rod-drop method, which were applied in this experiment. In the first method, the reactor is made supcritical by inserting the control rod to be calibrated a certain level. The rod drop method is to determine the subcritical;at the critical state, the rod to be calibrated is dropped into the core, and the resulting decay of neutron flux is observed and related to the reactivity. In this paper, the regulating rod will be calibrated according to the reactivity in OPR-1000 that corresponds to a certain control rod insert or withdraw, and the reactivity in power reactor depends?on the integral and differential control rod group too. The core simulator OPR1000 is used to test those methods. 展开更多
关键词 control ROD The ASYMPTOTIC Period METHOD The Rod-drop METHOD CORE SIMULATOR OPR1000
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自适应虚拟阻抗的微电网二次补偿控制策略研究
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作者 章宝歌 吕雄 +2 位作者 田浩 任勇全 崔福红 《哈尔滨工程大学学报》 北大核心 2025年第6期1179-1186,共8页
微电网中逆变器输出线路阻抗的差异会影响传统下垂控制的效果,导致负荷分配精度降低和电压跌落增大。针对目前传统下垂控制的不足,本文提出一种基于自适应虚拟阻抗的二次补偿控制策略。利用逆变器无功功率输出作为失配项,设计了自适应... 微电网中逆变器输出线路阻抗的差异会影响传统下垂控制的效果,导致负荷分配精度降低和电压跌落增大。针对目前传统下垂控制的不足,本文提出一种基于自适应虚拟阻抗的二次补偿控制策略。利用逆变器无功功率输出作为失配项,设计了自适应调整虚拟阻抗,可在逆变器输出线路阻抗不匹配的状况下,实现无功功率精准校正。对于由功率均分所造成的频率偏移和电压跌落现象,利用各分布式电源之间输出的频率和电压调整量作为下垂控制电压和频率的补偿量,设计了二次频率和电压恢复的补偿控制策略,实现频率和电压与原设定值同步,弥补在系统稳定运行时的频率偏移和电压跌落,提高了微电网的电能质量。在Matlab/Simulink中搭建孤岛微电网多台逆变器并联仿真模型,通过仿真结果分析验证了本文控制策略的有效性、可行性和可拓展性。 展开更多
关键词 分布式电源 下垂控制 自适应虚拟阻抗 功率校正 频率偏移 电压跌落 二次补偿控制 电能质量
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低浓度阿托品滴眼液防控儿童近视的应用效果 被引量:1
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作者 林春堤 熊永强 +2 位作者 童林利 林琳 吕月娥 《中国现代药物应用》 2025年第22期99-101,共3页
目的研究低浓度阿托品滴眼液用于儿童近视防控中的效果。方法选择近视儿童100例作为研究对象,用随机数表法分为对照组及观察组,每组50例。对照组实施视觉训练,观察组在对照组基础上增加低浓度(0.01%)阿托品滴眼液治疗。比较两组患儿的... 目的研究低浓度阿托品滴眼液用于儿童近视防控中的效果。方法选择近视儿童100例作为研究对象,用随机数表法分为对照组及观察组,每组50例。对照组实施视觉训练,观察组在对照组基础上增加低浓度(0.01%)阿托品滴眼液治疗。比较两组患儿的屈光度、眼轴长度、眼压。结果治疗后,两组屈光度优于本组治疗前,且观察组屈光度(-2.46±0.10)优于对照组的(-2.31±0.12),有显著性差异(P<0.05)。治疗后,两组眼轴长度短于本组治疗前,且观察组眼轴长度(21.04±1.08)mm短于对照组的(22.31±1.24)mm,有显著性差异(P<0.05)。治疗后,两组眼压高于本组治疗前,且观察组眼压(17.95±1.50)mm Hg(1 mm Hg=0.133 kPa)高于对照组的(16.92±1.63)mm Hg,有显著性差异(P<0.05)。结论低浓度阿托品滴眼液更有利于儿童近视的防控,对于改善患儿的眼压、眼轴长度和屈光度有积极意义,配合实施视觉训练有理想效果,临床上值得推广和应用。 展开更多
关键词 低浓度 阿托品滴眼液 视觉训练 儿童 近视 防控效果
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基于综合补偿的改进下垂控制研究
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作者 巫付专 尹清森 +2 位作者 朱永胜 张一鸣 梁铭心 《中原工学院学报》 2025年第5期21-30,共10页
对于在低压微电网中采用下垂控制的并网逆变器,由于下垂控制特性与虚拟电感的作用,当电网频率下降时,系统输出的功率因数降低且冲击电流增大。针对该问题,首先,阐述了系统输出的无功功率随电网频率变化而波动的原因,提出了一种基于综合... 对于在低压微电网中采用下垂控制的并网逆变器,由于下垂控制特性与虚拟电感的作用,当电网频率下降时,系统输出的功率因数降低且冲击电流增大。针对该问题,首先,阐述了系统输出的无功功率随电网频率变化而波动的原因,提出了一种基于综合补偿的改进下垂控制。改进后的下垂控制能够动态地调整逆变器输出端电压的幅值与相位,在提高系统输出功率因数的同时减小了电网频率降低时系统的冲击电流。其次,通过建立并网逆变器的小信号模型对基于综合补偿的改进下垂控制进行了稳定性分析。最后,通过仿真和实验分析验证了基于综合补偿的改进下垂控制能有效抑制电网频率发生波动时输出的冲击电流增大、功率因数降低。研究提高了系统的效率,降低了系统的损耗。 展开更多
关键词 并网逆变器 下垂控制 综合补偿 功率因数 小信号分析
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杨梅内生芽孢杆菌对采前落果和肉葱病的防效评价
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作者 陈官菊 梁秀美 +6 位作者 荀倩 孔凡轩 宋洋 何如意 单琳雯 郭秀珠 夏海涛 《中国果树》 2025年第11期100-103,共4页
杨梅采前落果和肉葱病严重影响果实产量和品质,而现有化学防控手段存在药害及残留风险。基于杨梅枝干内生芽孢杆菌研制复合微生物菌剂,评估其对丁岙梅采前落果和肉葱病的防控效果。田间试验结果表明:1×10^(5)cfu/mL和5×10^(4)... 杨梅采前落果和肉葱病严重影响果实产量和品质,而现有化学防控手段存在药害及残留风险。基于杨梅枝干内生芽孢杆菌研制复合微生物菌剂,评估其对丁岙梅采前落果和肉葱病的防控效果。田间试验结果表明:1×10^(5)cfu/mL和5×10^(4)cfu/mL复合微生物菌剂处理落果防控效果(66.58%、66.34%)与375 mg/L8%对氯苯氧乙酸钠处理(67.83%)相当,且无药害风险;同时,1×10^(5)cfu/mL复合微生物菌剂处理对肉葱病的防控效果(66.90%)显著优于375 mg/L 8%对氯苯氧乙酸钠处理(57.18%),应用前景较好。 展开更多
关键词 杨梅 采前落果 肉葱病 芽孢杆菌 防控效果
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