期刊文献+
共找到5,737篇文章
< 1 2 250 >
每页显示 20 50 100
MODIFIED AUTOMATIC TUNING OF PI/D CONTROLLERS BASED ON PHASE AND AMPLITUDE MARGIN SPECIFICATIONS
1
作者 王亚刚 邵惠鹤 《Journal of Shanghai Jiaotong university(Science)》 EI 1999年第2期17-21,共5页
A new auto tuning procedure for PI/D controller based on phase and amplitude margin specifications was proposed.The procedure applied a modified relay feedback experiment to identifying the process frequency response ... A new auto tuning procedure for PI/D controller based on phase and amplitude margin specifications was proposed.The procedure applied a modified relay feedback experiment to identifying the process frequency response of the point where the Nyquist curve intersects the negative imaginary axis,and the PI/D controller settings can be obtained based on this single point.The auto tuning method has all the merits of the tuning method that Astrom and Hagglund had proposed,and overcomes its problems.The simulation results show that the proposed tuning method has better performance than Astrom Hagglund’s tuning method. 展开更多
关键词 RELAY FEEdBACK pi/d control AUTO tuning frequency response
在线阅读 下载PDF
Optimized control of grid-connected photovoltaic systems:Robust PI controller based on sparrow search algorithm for smart microgrid application
2
作者 Youssef Akarne Ahmed Essadki +2 位作者 Tamou Nasser Maha Annoukoubi Ssadik Charadi 《Global Energy Interconnection》 2025年第4期523-536,共14页
The integration of renewable energy sources into modern power systems necessitates efficient and robust control strategies to address challenges such as power quality,stability,and dynamic environmental variations.Thi... The integration of renewable energy sources into modern power systems necessitates efficient and robust control strategies to address challenges such as power quality,stability,and dynamic environmental variations.This paper presents a novel sparrow search algorithm(SSA)-tuned proportional-integral(PI)controller for grid-connected photovoltaic(PV)systems,designed to optimize dynamic perfor-mance,energy extraction,and power quality.Key contributions include the development of a systematic SSA-based optimization frame-work for real-time PI parameter tuning,ensuring precise voltage and current regulation,improved maximum power point tracking(MPPT)efficiency,and minimized total harmonic distortion(THD).The proposed approach is evaluated against conventional PSO-based and P&O controllers through comprehensive simulations,demonstrating its superior performance across key metrics:a 39.47%faster response time compared to PSO,a 12.06%increase in peak active power relative to P&O,and a 52.38%reduction in THD,ensuring compliance with IEEE grid standards.Moreover,the SSA-tuned PI controller exhibits enhanced adaptability to dynamic irradiancefluc-tuations,rapid response time,and robust grid integration under varying conditions,making it highly suitable for real-time smart grid applications.This work establishes the SSA-tuned PI controller as a reliable and efficient solution for improving PV system performance in grid-connected scenarios,while also setting the foundation for future research into multi-objective optimization,experimental valida-tion,and hybrid renewable energy systems. 展开更多
关键词 Smart microgrid Photovoltaic system pi controller Sparrow search algorithm GRId-CONNECTEd Metaheuristic optimization
在线阅读 下载PDF
KMT2D调控PI3K/AKT信号通路促进食管鳞状细胞癌发展 被引量:1
3
作者 周珍 魏娉 +3 位作者 姜琳娜 何鹏 尹峰 安欣 《解剖科学进展》 2025年第1期55-57,61,共4页
目的 研究KMT2D与PI3K/AKT信号通路在食管鳞状细胞癌的发展中的相互作用机制。方法 通过免疫组化实验分析癌组织和癌旁组织KMT2D的表达水平;将KYSE-410细胞分为pcDNA NC组、pcDNA KMT2D和LY294002组。细胞集落形成实验检测KYSE-410细胞... 目的 研究KMT2D与PI3K/AKT信号通路在食管鳞状细胞癌的发展中的相互作用机制。方法 通过免疫组化实验分析癌组织和癌旁组织KMT2D的表达水平;将KYSE-410细胞分为pcDNA NC组、pcDNA KMT2D和LY294002组。细胞集落形成实验检测KYSE-410细胞生长能力;Transwell实验分析KYSE-410细胞侵袭能力;流式细胞术分析KYSE-410细胞凋亡率;蛋白免疫印迹实验分析KMT2D对PI3K/AKT通路的调控作用。结果 癌组织中KMT2D表达水平降低。与pcDNA NC组相比,pcDNA KMT2D组和LY294002组的KYSE-410细胞的集落形成数量和侵袭能力降低、凋亡率增加、PI3K和AKT蛋白磷酸化水平下降。结论 KMT2D能够抑制食管鳞状细胞癌KYSE-410细胞的生长和侵袭,促进KYSE-410细胞的凋亡,并且KMT2D这一作用与抑制PI3K/AKT信号通路激活有关。 展开更多
关键词 食管鳞状细胞癌 KMT2d pi3K AKT 侵袭 凋亡
原文传递
基于模糊PI^(λ)D^(μ)的气液两相混合式低温氮气射流温度控制方法
4
作者 李虓猇 杨东 《中南大学学报(自然科学版)》 北大核心 2025年第5期1817-1825,共9页
为精准控制超低温加工中低温氮气射流冷却温度,解决系统强非线性、输入受限及响应迟缓等问题,提出一种具有抗积分饱和功能的模糊分数阶PID控制方法。首先,基于气液混合系统硬件结构,在AMESim平台建立低温射流管路仿真模型,通过多物理场... 为精准控制超低温加工中低温氮气射流冷却温度,解决系统强非线性、输入受限及响应迟缓等问题,提出一种具有抗积分饱和功能的模糊分数阶PID控制方法。首先,基于气液混合系统硬件结构,在AMESim平台建立低温射流管路仿真模型,通过多物理场耦合仿真表征氮气传输过程的动态特性;其次,以管路模型为控制对象,设计双输入三输出的模糊分数阶PID控制器,以目标温度及温差作为模糊输入,以参数修正量Δk_(p)、Δk_(i)、Δk_(d)作为输出,基于49条Sugeno型模糊规则动态修正控制参数,并集成抗积分饱和算法抑制执行器饱和;最后,构建AMESim-Simulink联合仿真环境,以调节时间和稳态误差为优化目标,采用改进的粒子群优化算法对控制参数k_(p)、k_(i)、k_(d)及分数阶次λ、μ进行全局寻优。研究结果表明:在设定的-80℃和-140℃温度目标中,所提出的方法的调节时间较最优PID分别缩短58.27%和25.85%,较分数阶PID分别缩短64.82%和11.17%,峰值时间较最优PID分别减少29.80%和8.53%,较分数阶PID分别减少34.77%和9.81%,温度稳态误差控制在±0.5℃以内。该控制器通过模糊逻辑的自适应性与分数阶算子的记忆特性协同,有效提升了低温射流系统的动态响应和稳态精度。 展开更多
关键词 超低温加工 温度控制 模糊pi^(λ)d^(μ) 低温氮气射流 AMESim-Simulink联合仿真
在线阅读 下载PDF
PTPRD去甲基化通过PI3K/Akt/mTOR通路调控胃癌细胞的增殖、迁移及化疗耐药性
5
作者 刘妍慧 高紫玉 +3 位作者 任鹏 杜予馨 刘彩霞 邢智伟 《中国肿瘤生物治疗杂志》 北大核心 2025年第1期48-55,共8页
目的:探究蛋白酪氨酸磷酸酶D(PTPRD)去甲基化通过PI3K/Akt/mTOR通路对胃癌细胞增殖、迁移及化疗耐药性的影响。方法:体外培养胃癌细胞MKN-74、MKN-45和人胃黏膜上皮细胞GES-1并检测PTPRD表达。常规培养MKN-45细胞及耐药MKN-45/5-FU细胞... 目的:探究蛋白酪氨酸磷酸酶D(PTPRD)去甲基化通过PI3K/Akt/mTOR通路对胃癌细胞增殖、迁移及化疗耐药性的影响。方法:体外培养胃癌细胞MKN-74、MKN-45和人胃黏膜上皮细胞GES-1并检测PTPRD表达。常规培养MKN-45细胞及耐药MKN-45/5-FU细胞,分别转染PTPRD空载体(NC组、NC/5-FU组)、PTPRD过表达腺病毒(PTPRD组、PTPRD/5-FU组)、shRNA空载体(sh-NC组、sh-NC/5-FU组)、shRNA-PTPRD慢病毒(sh-PTPRD组、sh-PTPRD/5-FU组)和PTPRD过表达腺病毒+10μmol/L 740Y-P处理(PTPRD+740Y-P组、PTPRD+740Y-P/5-FU组)。MTT法、划痕愈合实验检测各组细胞的增殖活力和迁移能力,细胞自噬实验检测细胞的自噬水平,WB法检测细胞中EMT和PI3K/Akt/mTOR通路相关蛋白的表达。采用0、2.5、5、10、20、40μmol/L的5-aza处理MKN-45细胞,qPCR法、MTT法检测细胞中PTPRD mRNA表达和细胞增殖活力。结果:PTPRD mRNA和蛋白在胃癌细胞中均呈低表达(P<0.05)。与MKN-45组相比,PTPRD组自噬体与自噬溶酶体数量、PTPRD、上皮钙黏素(E-cadherin)、BAX蛋白表达均增加(均P<0.05),细胞增殖活力、细胞迁移率、p-PI3K、波形蛋白(vimentin)、p-Akt、p-mTOR蛋白表达均降低(均P<0.05),sh-PTPRD组细胞增殖活力、细胞迁移率、p-PI3K、vimentin、p-Akt、p-mTOR蛋白表达均增加(均P<0.05),自噬体与自噬溶酶体数量、PTPRD、E-cadherin、BAX蛋白表达均减少(均P<0.05);与PTPRD组相比,PTPRD+740Y-P组细胞增殖活力、细胞迁移率、p-PI3K、vimentin、p-Akt、p-mTOR蛋白表达均增加(均P<0.05),自噬体与自噬溶酶体数量、PTPRD、E-cadherin、BAX蛋白表达减少(均P<0.05)。随着5-aza浓度的增加,MKN-45细胞中PTPRD mRNA表达增加、细胞增殖活力均降低(均P<0.05)。与MKN-45/5-FU组相比,PTPRD/5-FU组细胞迁移率、细胞增殖活力均降低(均P<0.05),sh-PTPRD/5-FU组细胞迁移率、细胞增殖活力均增加(均P<0.05);与PTPRD/5-FU组相比,PTPRD+740Y-P/5-FU组细胞迁移率、细胞增殖活力均增加(均P<0.05)。结论:PTPRD在胃癌细胞中呈低表达状态,PTPRD去甲基化可能通过抑制PI3K/Akt/mTOR信号通路抑制胃癌细胞增殖、迁移并增强其对化疗的敏感性。 展开更多
关键词 蛋白酪氨酸磷酸酶d 胃癌 增殖 迁移 pi3K/Akt/mTOR通路 化疗耐药性 甲基化
原文传递
Psychological effects of virtual reality intervention on breast cancer patients with different personalities: A randomized controlled trial 被引量:4
6
作者 Shanshan Wu Guodu Liu +9 位作者 Jie Yang Xinxin Xie Mei-E Wu Lili Wang Yanhui Zhang Jinmei Chen Xiaowei Wang Wanjiao Li Yihong Qiu Jie Chen 《International Journal of Nursing Sciences》 2025年第2期107-114,共8页
Objectives:To explore the efficacy and safety of virtual reality(VR)in relieving negative emotions in patients with breast cancer with different personalities.Methods:A randomized controlled trial was conducted.Betwee... Objectives:To explore the efficacy and safety of virtual reality(VR)in relieving negative emotions in patients with breast cancer with different personalities.Methods:A randomized controlled trial was conducted.Between April 2023 and October 2023,we enrolled patients with breast cancer treated in the Department of Breast Cancer and Oncology at Sun Yat-Sen Memorial Hospital,Sun Yat-Sen University,Guangdong Province.The patients were randomly divided into an intervention group(n=118)and a control group(n=119)using block randomization.The intervention group received the VR intervention 3-5 times over 5±2 weeks using natural landscapes with music or relaxation guidance,and the duration of each VR intervention was 15±3 min.The control group received routine nursing care,including disease education and psychological counseling.Patients were assessed using the Type D Scale,Positive and Negative Affect Scale,and Distress Thermometer,and adverse events during the intervention were recorded.Results:Overall,85 patients completed the study(44 in the intervention group and 41 in the control group).Patients with Type D personalities showed more negative emotions[25.0(21.5,27.5)vs.19.0(16.0,24.0),P=0.001]and distressed attitudes[4.0(2.0,5.0)vs.3.0(1.0,4.0),P=0.020]with fewer positive emotions(27.2±5.6 vs.31.0±5.9,P=0.014)than those with non-Type D personalities.Total population analysis revealed no significant differences between the groups.However,in the subgroup analysis,patients with Type D personalities in the intervention group showed greater relief from negative emotions than those in the control group[median difference,-5.0(-9.0,-2.5)vs.-2.0(-4.0,2.0),P=0.046].No significant differences were found between groups of patients with non-Type D personality traits.The proportion of adverse events was not significantly different between groups(P=0.110).Conclusions:Breast cancer patients with Type D personalities suffer more severe negative emotions and distress,and more attention should be paid to them.VR intervention significantly and safely reduced negative emotions in patients with Type D personalities. 展开更多
关键词 Breast neoplasms Rehabilitation research Randomized controlled trial Type d personality Virtual reality
暂未订购
高频驱动大功率电动式扬声器的分数阶PID控制
7
作者 赵景玉 李志远 +3 位作者 赵弘毅 刘扬 张传营 卜凡亮 《科学技术与工程》 北大核心 2025年第25期10782-10791,共10页
针对高频电压驱动下大功率电动式扬声器控制精度不足的问题,设计了一种基于D分解方法的分数阶比例-积分-微分(proportion-integration-differentiation,PID)控制器,提出了一种高效的控制器参数整定策略,给出了一种新的模型参数误差对控... 针对高频电压驱动下大功率电动式扬声器控制精度不足的问题,设计了一种基于D分解方法的分数阶比例-积分-微分(proportion-integration-differentiation,PID)控制器,提出了一种高效的控制器参数整定策略,给出了一种新的模型参数误差对控制器鲁棒性影响的计算方法。将所设计的控制器应用于高频信号驱动的电动式扬声器模型进行测试。实验结果显示,与传统控制器相比,新设计的分数阶PID控制器在调节时间上减少了6.07 ms,在峰值时间上减少了1.03 ms,稳态相对误差降低了0.5675%。此外,控制系统的鲁棒性显著提高,只保留一个敏感频率点,并且鲁棒性界的极小值提升了9.06‰。这些改进显著提升了电动式扬声器的控制效果,为大功率高频驱动设备的控制提供了新的解决方案。 展开更多
关键词 大功率电动式扬声器 分数阶pid控制器 d分解方法 控制器鲁棒性界
在线阅读 下载PDF
Machine Learning-Based Online Monitoring and Closed-Loop Controlling for 3D Printing of Continuous Fiber-Reinforced Composites 被引量:1
8
作者 Xinyun Chi Jiacheng Xue +6 位作者 Lei Jia Jiaqi Yao Huihui Miao Lingling Wu Tengfei Liu Xiaoyong Tian Dichen Li 《Additive Manufacturing Frontiers》 2025年第2期90-96,共7页
Ensuring the consistent mechanical performance of three-dimensional(3D)-printed continuous fiber-reinforced composites is a significant challenge in additive manufacturing.The current reliance on manual monitoring exa... Ensuring the consistent mechanical performance of three-dimensional(3D)-printed continuous fiber-reinforced composites is a significant challenge in additive manufacturing.The current reliance on manual monitoring exacerbates this challenge by rendering the process vulnerable to environmental changes and unexpected factors,resulting in defects and inconsistent product quality,particularly in unmanned long-term operations or printing in extreme environments.To address these issues,we developed a process monitoring and closed-loop feedback control strategy for the 3D printing process.Real-time printing image data were captured and analyzed using a well-trained neural network model,and a real-time control module-enabled closed-loop feedback control of the flow rate was developed.The neural network model,which was based on image processing and artificial intelligence,enabled the recognition of flow rate values with an accuracy of 94.70%.The experimental results showed significant improvements in both the surface performance and mechanical properties of printed composites,with three to six times improvement in tensile strength and elastic modulus,demonstrating the effectiveness of the strategy.This study provides a generalized process monitoring and feedback control method for the 3D printing of continuous fiber-reinforced composites,and offers a potential solution for remote online monitoring and closed-loop adjustment in unmanned or extreme space environments. 展开更多
关键词 Continuous fiber-reinforced composites 3d printing Computer vision Machine learning defect detection Feedback control
在线阅读 下载PDF
Optimal load frequency control system for two-area connected via AC/DC link using cuckoo search algorithm
9
作者 Gaber EL-SAADY Alexey MIKHAYLOV +2 位作者 Nora BARANYAI Mahrous AHMED Mahmoud HEMEIDA 《虚拟现实与智能硬件(中英文)》 2025年第3期299-316,共18页
Background Interconnection of different power systems has a major effect on system stability.This study aims to design an optimal load frequency control(LFC)system based on a proportional-integral(PI)controller for a ... Background Interconnection of different power systems has a major effect on system stability.This study aims to design an optimal load frequency control(LFC)system based on a proportional-integral(PI)controller for a two-area power system.Methods Two areas were connected through an AC tie line in parallel with a DC link to stabilize the frequency of oscillations in both areas.The PI parameters were tuned using the cuckoo search algorithm(CSA)to minimize the integral absolute error(IAE).A state matrix was provided,and the stability of the system was verified by calculating the eigenvalues.The frequency response was investigated for load variation,changes in the generator rate constraint,the turbine time constant,and the governor time constant.Results The CSA was compared with particle swarm optimization algorithm(PSO)under identical conditions.The system was modeled based on a state-space mathematical representation and simulated using MATLAB.The results demonstrated the effectiveness of the proposed controller based on both algorithms and,it is clear that CSA is superior to PSO.Conclusion The CSA algorithm smoothens the system response,reduces ripples,decreases overshooting and settling time,and improves the overall system performance under different disturbances. 展开更多
关键词 Load frequency control Cuckoo search algorithm pi controllers State space modeling
在线阅读 下载PDF
Attitude control of flexible satellite via three-dimensional magnetically suspended wheel
10
作者 J.TAYEBI Yingjie CHEN +1 位作者 Ti CHEN Shiyuan JIA 《Applied Mathematics and Mechanics(English Edition)》 2025年第3期555-572,共18页
This paper proposes an attitude control strategy for a flexible satellite equipped with an orthogonal cluster of three-dimensional(3D)magnetically suspended wheels(MSWs).The mathematical model for the satellite incorp... This paper proposes an attitude control strategy for a flexible satellite equipped with an orthogonal cluster of three-dimensional(3D)magnetically suspended wheels(MSWs).The mathematical model for the satellite incorporating flexible appendages and an orthogonal cluster of magnetically suspended reaction wheel actuators is initially developed.After that,an adaptive attitude controller is designed with a switching surface of variable structure,an adaptive law for estimating inertia matrix uncertainty,and a fuzzy disturbance observer for estimating disturbance torques.Additionally,a Moore-Penrose-based steering law is proposed to derive the tilt angle commands of the orthogonal configuration of the 3D MSW to follow the designed control signal.Finally,numerical simulations are presented to validate the effectiveness of the proposed control strategy. 展开更多
关键词 flexible satellite three-dimensional(3d)magnetically suspended wheel(MSW) attitude control adaptive control disturbance observer
在线阅读 下载PDF
Monolithically 3D-nanoprinted millimeter-scale lens actuator for dynamic focus control in optical systems
11
作者 Florian Lux Aybuke Calikoglu Çağlar Ataman 《Advanced Photonics Nexus》 2025年第4期140-153,共14页
Three-dimensional(3D)nanoprinting via two-photon polymerization offers unparalleled design flexibility and precision,thereby enabling rapid prototyping of advanced micro-optical elements and systems that have found im... Three-dimensional(3D)nanoprinting via two-photon polymerization offers unparalleled design flexibility and precision,thereby enabling rapid prototyping of advanced micro-optical elements and systems that have found important applications in endomicroscopy and biomedical imaging.The potential of this versatile tool for monolithic manufacturing of dynamic micro-opto-electro-mechanical systems(MOEMSs),however,has not yet been sufficiently explored.This work introduces a 3D-nanoprinted lens actuator with a large optical aperture,optimized for remote focusing in miniaturized imaging systems.The device integrates orthoplanar linear motion springs,a self-aligned sintered micro-magnet,and a monolithic lens,actuated by dual microcoils for uniaxial motion.The use of 3D nanoprinting allows complete design freedom for the integrated optical lens,whereas the monolithic fabrication ensures inherent alignment of the lens with the mechanical elements.With a lens diameter of 1.4 mm and a compact footprint of 5.74 mm,it achieves high mechanical robustness at resonant frequencies exceeding 300 Hz while still providing a large displacement range of 200μm(±100μm).A comprehensive analysis of optical and mechanical performance,including the effects of coil temperature and polymer viscoelasticity,demonstrates its advantages over conventional micro-electro-mechanical system actuators,showcasing its potential for next-generation imaging applications. 展开更多
关键词 micro-electro-mechanical system scanner two-photon polymerization 3d nanoprinting dynamic focus control electromagnetic actuation
在线阅读 下载PDF
Surrounding rock deformation characteristics and control strategies during passing through abandoned roadway group
12
作者 YANG Feng SUN Qiang +2 位作者 ZHOU Nan CHEN Yong WEI Yongqi 《Journal of Mountain Science》 2025年第7期2707-2722,共16页
The disorderly mining activities and irrational layout in underground coal mines have left a large number of adjacent abandoned roadways.During the process of a working face passing through abandoned roadways,these st... The disorderly mining activities and irrational layout in underground coal mines have left a large number of adjacent abandoned roadways.During the process of a working face passing through abandoned roadways,these structures are prone to varying degrees of damage,with frequent occurrences of roof leakage and induced rock burst accidents,significantly impacting subsequent mining operations and safe production.To address these issues,this study investigates the surrounding rock deformation patterns during fully mechanized mining face passage through abandoned roadway clusters.Specific countermeasures were systematically summarized according to different occurrence characteristics of abandoned roadways.Through mechanical analysis,the critical unstable width of coal pillars was determined to be approximately 16.1~16.8 m.A three-dimensional numerical model was established based on 17 abandoned roadways with various shapes and occurrences in the working face.Simulation results indicate severe deformation and failure in roof rock layer roadways,while floor roadways exhibit relatively minor damage.Notably,when the distance between abandoned roadways and the coal seam exceeds 8 m,almost no damage occurs.Three technical measures for passing through abandoned roadway group was proposed according to their occurrence characteristics and implemented in engineering practice.Field applications demonstrate limited coal stress variations and weak strata pressure manifestations during the crossing process,ensuring safe passage through abandoned roadway clusters.This achievement enables efficient and safe crossing of abandoned roadway group in fully mechanized mining faces,enhances coal recovery rates,and provides practical engineering references for similar geological conditions. 展开更多
关键词 Abandoned roadway group 3d abandoned roadway model Numerical simulation control strategies Engineering application
原文传递
Silencing NCAPD3 Inhibits Tumor Growth and Metastasis in Hepatocellular Carcinoma by Suppressing PI3K-AKT Signalling Pathway
13
作者 Jun Lv Fu-yuan Gan +1 位作者 Ming-hao Li Qing-jun Yin 《Current Medical Science》 2025年第2期253-263,共11页
Objective To evaluate the expression pattern of non-SMC condensin II complex subunit D3(NCAPD3)in hepatocellular carcinoma(HCC)tissues,assess its association with clinical characteristics,and explore the effects of NC... Objective To evaluate the expression pattern of non-SMC condensin II complex subunit D3(NCAPD3)in hepatocellular carcinoma(HCC)tissues,assess its association with clinical characteristics,and explore the effects of NCAPD3 on HCC cells and the potential underlying mechanisms.Methods NCAPD3 expression in HCC tumors and adjacent noncancerous tissues was quantified via quantitative PCR.Patients were divided into high-and low-expression groups on the basis of NCAPD3 levels,and associations with clinical parameters were assessed.The effects of NCAPD3 knockdown and the phosphatidylinositol-3-kinase(PI3K)agonist Y-P 740 on cell functions were examined via cell proliferation,Transwell migration,and invasion assays.Differentially expressed genes following NCAPD3 knockdown in SMMC-7721 cells were identified via mRNA sequencing.Western blotting was performed to measure NCAPD3,AKT serine/threonine kinase 1(AKT1),and phosphorylated AKT1 levels.Results NCAPD3 mRNA expression was notably upregulated in HCC tissues as compared with that in adjacent noncancer tissues.A positive correlation was observed between NCAPD3 expression and both lymphatic and distant metastases in patients with HCC.NCAPD3 knockdown reduced the proliferation and metastasis of SMMC-7721 and Huh-7 cells.mRNA sequencing revealed 140 downregulated genes and 125 upregulated genes.Further validation experiments confirmed that NCAPD3 modulated the PI3K-AKT signalling pathway and that the PI3K agonist Y-P 740 counteracted the effects of NCAPD3 knockdown.Conclusions Elevated NCAPD3 expression was strongly correlated with HCC metastasis.NCAPD3 inhibition impedes HCC cell growth and metastatic potential by suppressing the PI3K–AKT signalling pathway. 展开更多
关键词 Hepatocellular carcinoma Non-SMC condensin II complex subunit d3 pi3K-AKT signalling pathway ONCOGENE
暂未订购
基于PI系统的DCS硬件状态实时监测与智能维护体系研究
14
作者 姚建英 《计算机应用文摘》 2025年第20期142-144,共3页
随着工业自动化进程不断深入,分布式控制系统(DCS)已成为现代工业生产过程的核心控制架构.然而,DCS硬件设备在长期运行中易出现老化、磨损及性能退化等问题,一旦发生故障,可能导致生产中断、经济损失甚至安全事故.作为高性能过程信息管... 随着工业自动化进程不断深入,分布式控制系统(DCS)已成为现代工业生产过程的核心控制架构.然而,DCS硬件设备在长期运行中易出现老化、磨损及性能退化等问题,一旦发生故障,可能导致生产中断、经济损失甚至安全事故.作为高性能过程信息管理平台,工厂信息(PI)系统具备强大的实时数据采集、存储与分析能力,为DCS硬件设备的监测与维护提供了新的技术路径.通过构建基于PI系统的实时监测平台,并结合智能化维护体系,可实现对控制器、I/O模块及通信网络等关键硬件的状态实时监控、性能劣化预测与智能维护决策,从而显著减少非计划停机时间,延长设备使用寿命,优化维护资源配置,为工业企业的稳定运行与经济效益提升提供可靠保障. 展开更多
关键词 pi系统 分布式控制系统 实时监测 智能维护 预测性维护
在线阅读 下载PDF
基于FSMPI的新能源汽车双向DC-DC变换器控制策略
15
作者 吴浙勋 林棋涛 +1 位作者 葛愿 林其友 《菏泽学院学报》 2025年第2期57-66,共10页
双向DC-DC变换器是新能源汽车混合动力系统的关键部件,为解决传统比例积分控制下双向DC-DC变换器在动态响应速度与抗干扰能力方面的不足,设计了一种基于前馈变结构比例积分控制(Feedforward Sliding Mode PI Control,FSMPI)的双向DC-DC... 双向DC-DC变换器是新能源汽车混合动力系统的关键部件,为解决传统比例积分控制下双向DC-DC变换器在动态响应速度与抗干扰能力方面的不足,设计了一种基于前馈变结构比例积分控制(Feedforward Sliding Mode PI Control,FSMPI)的双向DC-DC变换器控制策略.该策略利用变结构控制对干扰信号的实时信息进行补偿,并结合前馈控制,以增强系统的鲁棒性.为验证所提控制策略的有效性,通过仿真与STM32F4实验平台上的对比实验,评估了其与传统比例积分控制的性能差异.结果表明,在负载变化时,采用前馈变结构比例积分控制的变换器具有更好的动态性能和鲁棒性. 展开更多
关键词 新能源汽车 混合动力系统 双向dC-dC变换器 前馈变结构比例积分控制
在线阅读 下载PDF
DAB储能变换器双闭环模型预测控制与PI补偿控制策略研究 被引量:4
16
作者 陈桂涛 宋晨飞 +2 位作者 刘飞飞 黄伯雄 孙向东 《太阳能学报》 EI CAS CSCD 北大核心 2024年第8期1-9,共9页
针对直流微电网中分布式电源输入输出功率不稳定造成的直流母线电压波动问题,鉴于双有源桥(DAB)储能变换器具有能量双向流动的特点,提出一种基于内模原理的双闭环模型预测控制策略。在分析DAB变换器扩展移相调制原理与特性基础上,重点... 针对直流微电网中分布式电源输入输出功率不稳定造成的直流母线电压波动问题,鉴于双有源桥(DAB)储能变换器具有能量双向流动的特点,提出一种基于内模原理的双闭环模型预测控制策略。在分析DAB变换器扩展移相调制原理与特性基础上,重点研究电压外环和电流内环的模型预测控制策略。针对模型预测控制性能依赖电路参数准确度问题,分别从电路主要参数失配对功率传输和直流母线稳压的影响两个角度出发,深入分析模型参数敏感度。最终设置直流母线电压稳态误差灵敏度区,在误差灵敏度区外仅采用双闭环模型预测控制以保证系统的动态响应性能,在误差灵敏度区内采用双闭环模型预测控制和PI补偿控制以消除系统稳态误差。搭建实验平台进行实验验证,结果表明:在系统受到扰动时,DAB储能变换器可实现快速地充放电对系统进行补偿,混合控制策略可快速保持母线电压的稳定,实现系统功率均衡,增强系统抗扰能力。 展开更多
关键词 微电网 变换器 直流母线电压波动 双有源桥 扩展移相 双闭环模型预测控制 pi补偿控制
原文传递
基于Bode图解法的改进频域框架分数阶PI控制器设计方法 被引量:1
17
作者 邵克勇 刘洋 +2 位作者 孙辰俊 夏文静 朱玉洁 《东北石油大学学报》 北大核心 2024年第6期109-116,I0008,共9页
为了有效减少求解分数阶PI控制器参数的计算量,基于Bode图解法,提出一种改进频域框架分数阶PI控制器设计方法。将改进频域框架法引入中频段,求取改进频域框架法的三角形面积最小;根据截止频率、相角穿越频率约束公式,确定改进频域框架范... 为了有效减少求解分数阶PI控制器参数的计算量,基于Bode图解法,提出一种改进频域框架分数阶PI控制器设计方法。将改进频域框架法引入中频段,求取改进频域框架法的三角形面积最小;根据截止频率、相角穿越频率约束公式,确定改进频域框架范围;考虑多种约束条件,引入拉格朗日乘数方程,计算比例系数和积分系数,求取在某一改进频域框架内的最优比例系数和积分系数;通过仿真算例验证设计方法的可行性与有效性。结果表明:改进频域框架分数阶PI控制器设计满足系统的稳定性要求,有较好的鲁棒性。该设计方法具有计算简单、精确度高和取值范围直观等优点。 展开更多
关键词 分数阶 pi控制器 Bode图解法 最优控制 频域框架
在线阅读 下载PDF
基于动态逆分数阶PI^(λ)D^(μ)的高速飞行器控制器设计 被引量:1
18
作者 赵鹏飞 樊轶 秦昌茂 《飞行力学》 CSCD 北大核心 2024年第1期39-43,共5页
为提高高速再入飞行器的控制品质,开展了基于非线性动态逆解耦技术及分数阶PI^(λ)D^(μ)(FOPID)的控制技术研究。首先,在时标分离的基础上,建立了飞行器高速无动力再入模型。在此基础上,设计了动态逆分数阶PI^(λ)D^(μ)控制器进行了... 为提高高速再入飞行器的控制品质,开展了基于非线性动态逆解耦技术及分数阶PI^(λ)D^(μ)(FOPID)的控制技术研究。首先,在时标分离的基础上,建立了飞行器高速无动力再入模型。在此基础上,设计了动态逆分数阶PI^(λ)D^(μ)控制器进行了三通道解耦控制。仿真结果表明,相对于传统PID控制器,动态逆分数阶PI^(λ)D^(μ)控制器具有超调量小、响应快、稳态误差小等优点,以及良好的控制品质和鲁棒性,有利于高速飞行器的稳定控制。 展开更多
关键词 分数阶pi^(λ)d^(μ) 时标分离 高速飞行器 动态逆
原文传递
基于分数阶PID的火电厂烟气脱硝控制系统 被引量:1
19
作者 段宇 马敏阳 《能源与环境》 2024年第2期135-137,共3页
针对选择性催化还原(SCR)烟气脱硝控制对象具有大迟延、大惯性的动态特性,采用常规的PID控制器经常不能实现及时和准确的喷氨控制。设计了基于分数阶PIλDμ控制器的火电厂烟气脱硝控制系统,并对人群搜索算法(SOA)的种群进行动态排序和... 针对选择性催化还原(SCR)烟气脱硝控制对象具有大迟延、大惯性的动态特性,采用常规的PID控制器经常不能实现及时和准确的喷氨控制。设计了基于分数阶PIλDμ控制器的火电厂烟气脱硝控制系统,并对人群搜索算法(SOA)的种群进行动态排序和随机变异而提出改进人群搜索算法,采用改进SOA算法对分数阶PIλDμ控制器的参数进行优化。仿真表明,分数阶PIλDμ烟气脱硝串级系统可以在保证控制精确度的前提下有效减少喷氨控制的调节时间,提高控制的稳定性,实现更加稳定和及时的喷氨控制。 展开更多
关键词 分数阶piλdμ控制器 改进SOA算法 选择性催化还原 烟气脱硝
在线阅读 下载PDF
基于非线性动态重心粒子群优化的分数阶PI^(λ)D^(μ)控制器设计
20
作者 王仁明 刘闻仲 +2 位作者 鲍刚 张铭锐 杨婕 《控制工程》 CSCD 北大核心 2024年第6期1067-1074,共8页
针对现有Oustaloup滤波器拟合精度不佳、结构复杂的缺点,提出了最优精简Oustaloup滤波器。针对粒子群优化算法整定分数阶PI^(λ)D^(μ)控制器参数时学习能力不充分、迭代收敛乏力的问题,提出了一种改进的粒子群优化算法。该算法设计了... 针对现有Oustaloup滤波器拟合精度不佳、结构复杂的缺点,提出了最优精简Oustaloup滤波器。针对粒子群优化算法整定分数阶PI^(λ)D^(μ)控制器参数时学习能力不充分、迭代收敛乏力的问题,提出了一种改进的粒子群优化算法。该算法设计了双异步非线性动态学习因子,以提高粒子的思考能力与信息共享能力,并增加了粒子群质量重心项,用以加速收敛过程。将改进的算法结合最优精简Oustaloup滤波器应用于分数阶PI^(λ)D^(μ)控制器的设计过程,选取了2个分数阶系统模型进行仿真验证。结果表明,改进的算法收敛速度更快且不易陷入局部最优,所设计的控制系统超调量更小、调节时间更短、稳态误差更小,提高了系统的抗干扰能力。 展开更多
关键词 分数阶pi^(λ)d^(μ) 粒子群优化算法 Oustaloup滤波器 参数整定
原文传递
上一页 1 2 250 下一页 到第
使用帮助 返回顶部