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三种流动控制方法对H型垂直轴风力机性能影响的对比分析

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太阳能学报 2024年第3期45卷 105-115页

作者：刘永飞陈微圣孙晓晶上海理工大学能源与动力工程学院上海200093 上海市动力工程多相流动与传热重点实验室上海200093

采用数值模拟的方法,分别以基于NACA0021和NACA0018翼型表面带吸气缝叶片的升力型垂直轴风力机为二维、三维研究对象,研究叶片表面施加吸气对提高升力型(H型)垂直轴风力机叶片做功性能的效果。通过开展二维模拟研究,探究多吸气缝在叶片... 详细信息

采用数值模拟的方法,分别以基于NACA0021和NACA0018翼型表面带吸气缝叶片的升力型垂直轴风力机为二维、三维研究对象,研究叶片表面施加吸气对提高升力型(H型)垂直轴风力机叶片做功性能的效果。通过开展二维模拟研究,探究多吸气缝在叶片吸力面上的位置对垂直轴风力机气动性能的影响,并对比研究吸气和吹气这两种常用的主动流动控制方法提升垂直轴风力机风能利用净效率的区别。在此基础上,对叶片表面采用吸气控制的垂直轴风力机进行三维数值模拟分析,并将其获能特性与采用波浪前缘叶片即被动流动控制后的垂直轴风力机的性能进行了比较。结果表明,当多吸气缝位置位于距离叶片前缘10%~15%弦长区域范围内时,能最好地抑制垂直轴风力机叶片表面的流动分离,改善叶片的气动性能。与吹气控制方法相比,叶片表面采用吸气控制后的风力机的风能利用净效率在全叶尖速比下的增幅更加明显;而与波浪前缘控制方法相比,采用吸气控制后风力机风能利用净效率在低尖速比下提升效果更为显著,最大提升幅度可达到140%。该文研究结果表明吸气方式可使垂直轴风力机的效率在较大的运行工况内都有明显提高,与吹气和波浪前缘的方法相比在提升风力机气动性能效果方面更为显著,因此也更具工程应用的潜力和优势。

关键词：数值模拟垂直轴风力机流动控制吸气气动性能

维普期刊数据库博看期刊

关于蜡样芽孢杆菌片活菌数测定和杂菌检查方法的研究

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中国药学杂志 2024年第9期59卷 840-844页

作者：陈伟盛简敏骞刘瑜郑小玲广州市药品检验所广州510160 浙江省食品药品检验研究院杭州310004

目的对蜡样芽孢杆菌片现行标准中活菌数测定方法以及杂菌检查法的合理性进行探讨,并对这两法进行优化。方法对影响活菌数测定的因素,如培养基、稀释剂、稀释倍数、前处理方法,进行比较分析,选择较优的实验条件。使用微生态活菌制品总论... 详细信息

目的对蜡样芽孢杆菌片现行标准中活菌数测定方法以及杂菌检查法的合理性进行探讨,并对这两法进行优化。方法对影响活菌数测定的因素,如培养基、稀释剂、稀释倍数、前处理方法,进行比较分析,选择较优的实验条件。使用微生态活菌制品总论下的杂菌检查法替代标准中的微生物限度检查法,并对其适用性进行研究。结果优化后的活菌数测定方法可以更加有效地复苏样品中的蜡样芽孢杆菌,结果明显高于现行标准方法。采用新的杂菌检查法能检出非致病性杂菌,发现样品可能存在风险,其适用性结果基本符合《中国药典》的要求。结论新方法适用于蜡样芽孢杆菌片活菌数测定和杂菌检查。现行标准中的活菌数测定法以及微生物限度检查不能很好地监测产品的质量风险,建议对方法进行修订,这样既可以更有效地监管产品,又可以更好地帮助生产企业提高产品质量。

关键词：微生态活菌制剂杂菌检查活菌数测定辐射

Adaptive neural control of nonlinear periodic time-varying parameterized mixed-order multi-agent systems with unknown control coefficients

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Science China(Technological Sciences) 2022年第8期65卷 1675-1684页

作者： chen JiaXi chen weisheng LI JunMin ZHANG Shuai School of Mathematics and Statistics Xidian UniversityXi’an 710071China School of Aerospace Science and Technology Xidian UniversityXi’an 710071China Science and Technology on Antennas and Microwave Laboratory Xidian UniversityXi’an 710071China

In this paper, we first consider the adaptive leader-following consensus problem for a class of nonlinear parameterized mixedorder multi-agent systems with unknown control coefficients and time-varying disturbance parameters of the same period. Neural networks and Fourier series expansions are used to describe the unknown nonlinear periodic time-varying parameterized function.A distributed control protocol is designed based on adaptive control, matrix theory, and Nussbaum function. The robustness of the distributed control protocol is analyzed by combining the stability analysis theory of closed-loop systems. On this basis, this paper discusses the case of time-varying disturbance parameters with non-identical periods, expanding the application scope of this control protocol. Finally, the effectiveness of the algorithm is verified by a simulation example.

关键词： adaptive neural control unknown control coefficients mixed-order multi-agent systems periodic time-varying disturbances nonlinearly parameterized dynamics

Consensus control for heterogeneous uncertain multi-agent systems with hybrid nonlinear dynamics via iterative learning algorithm

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Science China(Technological Sciences) 2023年第10期66卷 2897-2906页

作者： XIE Jin chen JiaXi LI JunMin chen weisheng ZHANG Shuai School of Mathematics and Statistics Xidian UniversityXi’an 710071China School of Aerospace Science and Technology Xidian UniversityXi’an 710071China Science and Technology on Antennas and Microwave Laboratory Xidian UniversityXi’an 710071China

In this study,We propose a compensated distributed adaptive learning algorithm for heterogeneous multi-agent systems with repetitive motion,where the leader's dynamics are unknown,and the controlled system's parameters are *** multiagent systems are considered a kind of hybrid order nonlinear systems,which relaxes the strict requirement that all agents are of the same order in some existing *** theoretical analyses,we design a composite energy function with virtual gain parameters to reduce the restriction that the controller gain depends on global *** the stability of the controller,we introduce a smooth continuous function to improve the piecewise controller to avoid possible *** analyses prove the convergence of the presented algorithm,and simulation experiments verify the effectiveness of the algorithm.

关键词： multi-agent systems adaptive iterative learning control hybrid nonlinear dynamics composite energy function consensus algorithm

Output-feedback adaptive stochastic nonlinear stabilization using neural networks

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Journal of Systems Engineering and Electronics 2010年第1期21卷 81-87页

作者： weisheng chen Department of Applied Mathematics Xidian University Xi'an 710071 E R. China

For the first time, an adaptive backstepping neural network control approach is extended to a class of stochastic non- linear output-feedback systems. Different from the existing results, the nonlinear terms are assumed to be completely unknown and only a neural network is employed to compensate for all unknown nonlinear functions so that the controller design is more simplified. Based on stochastic LaSalle theorem, the resulted closed-loop system is proved to be globally asymptotically stable in probability. The simulation results further verify the effectiveness of the control scheme.

关键词： neural network output-feedback nonlinear stochastic systems backstepping.

经腋窝无充气后方入路腔镜甲状腺系膜切除术清扫右侧喉返神经深层(ⅥB区)淋巴结350例回顾性分析

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中华耳鼻咽喉头颈外科杂志 2024年第1期59卷 21-26页

作者：张植诚李婷婷余诗桐葛军娜魏志刚孙百慧陈伟生谭洁雷尚通南方医科大学南方医院普通外科广州510515

目的:探索经腋窝无充气后方入路腔镜甲状腺系膜切除术在清扫右侧喉返神经深层(ⅥB区)淋巴结的安全性及可行性。方法:回顾性分析2020年6月至2022年12月,南方医科大学南方医院普通外科采用经腋窝无充气后方入路腔镜甲状腺系膜切除术进行... 详细信息

目的:探索经腋窝无充气后方入路腔镜甲状腺系膜切除术在清扫右侧喉返神经深层(ⅥB区)淋巴结的安全性及可行性。方法:回顾性分析2020年6月至2022年12月,南方医科大学南方医院普通外科采用经腋窝无充气后方入路腔镜甲状腺系膜切除术进行治疗的右侧甲状腺乳头状癌(PTC)患者资料,术式均为甲状腺右侧叶及峡部切除术+右侧中央区淋巴清扫术。总结患者的临床、病理特点和术后并发症情况。采用SPSS 25.0软件对数据进行统计分析。结果:共入组350例患者,其中女性303例,男性47例,年龄(36.3±9.2)岁。pT1a期287例,pT1b期62例,pT2期1例,无T3及T4期患者。患者均顺利完成手术,没有中转开放。右侧中央区淋巴结清扫数目为(8.11±4.65)枚(范围:1~31枚)。右侧ⅥB区淋巴结清扫数目为(2.62±1.86)枚(范围:1~12枚)。14.86%(52/350)的患者存在ⅥB区淋巴结转移,0.86%(3/350)出现暂时性喉返神经损伤,0.86%(3/350)出现术后血肿。结论:经腋窝无充气后方入路腔镜甲状腺系膜切除术可以清扫ⅥB区淋巴结,是安全可行的。

关键词：甲状腺肿瘤腔镜甲状腺手术无充气腋窝入路右侧喉返神经深层淋巴结

ADAPTIVE TRACKING CONTROL FOR ACTUATOR FAILURE COMPENSATION BASED ON MT-FILTERS

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Journal of Systems Science & Complexity 2010年第4期23卷 759-768页

作者： Zhengqiang ZHANG weisheng chen School of Automation Nanjing University of Science and Technology Nanjing 210094 China Department of Electrical Engineering and Automation Qufu Normal University Rizhao 276826 China. Department of Applied Mathematics Xidian University Xian 710071 China

This paper considers the problem of actuator failure compensation for a class of nonlinearsystems in the form of ***-filters are exploited to estimate the unmeasured *** backsteppping technique is used to construct the controller *** proposed compensationscheme can grantee the boundedness of all the closed-loop signals and asymptotic output *** results are illustrated by a simulation example.

关键词： Actuator failure adaptive control backstepping MT-filters output feedback

Adaptive output-feedback control for MIMO nonlinear systems with time-varying delays using neural networks

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Journal of Systems Engineering and Electronics 2010年第5期21卷 850-858页

作者： weisheng chen Ruihong Li Department of Applied Mathematics Xidian University Xi'an 710071 E R. China

An adaptive neural network output-feedback regulation approach is proposed for a class of multi-input-multi-output nonlinear time-varying delayed *** the designed observer and controller are free from time *** from the existing results,this paper need not the assumption that the upper bounding functions of time-delay terms are known,and only a neural network is employed to compensate for all the upper bounding functions of time-delay terms,so the designed controller procedure is more *** addition,the resulting closed-loop system is proved to be semi-globally ultimately uniformly bounded,and the output regulation error converges to a small residual set around the *** simulation examples are provided to verify the effectiveness of control scheme.

关键词： neural network output-feedback nonlinear time-delay systems backstepping.

Adaptive neural network tracking control for a class of unknown nonlinear time-delay systems

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Journal of Systems Engineering and Electronics 2006年第3期17卷 611-618页

作者： chen weisheng Li Junmin Dept. of Applied Mathematics Xidian Univ. Xi'an 710071 P. R. China

For a class of unknown nonlinear time-delay systems, an adaptive neural network （NN） control design approach is proposed. Backstepping, domination and adaptive bounding design technique are combined to construct a robust memoryless adaptive NN tracking controller. Unknown time-delay functions are approximated by NNs, such that the requirement on the nonlinear time-delay functions is relaxed. Based on Lyapunov-Krasoviskii functional, the sem-global uniformly ultimately boundedness （UUB） of all the signals in the closed-loop system is proved. The arbitrary output tracking accuracy is achieved by tuning the design parameters. The feasibility is investigated by an illustrative simulation example.

关键词： nonlinear time-delay system neural network adaptive bounding technique memoryless adaptive NN controller.