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排序方式: 共有390条查询结果,搜索用时 15 毫秒
1.
软式操纵系统是通过钢索张力来传递操纵力的,钢索张力的变化直接影响飞机的操纵性能。张力调节器就是使钢索在各种状态下保持张力恒定的一种调节装置。对张力调节器的原理、结构形式进行了综合论述,并结合设计实例来说明钢索张力调节器的设计过程及设计中各参数的选取原则。 相似文献
2.
For the linear discrete time-invariant stochastic system with correlated noises,and with unknown model parameters and noise statistics,substituting the online consistent estimators of the model paramet... 相似文献
3.
Chi Nguyen Quynh Ho Minh Thi Tran Chung Chinh Doan Son Nghia Hoang Diem Hong Tran Long Thanh Le 《International journal of molecular sciences》2021,22(9)
Simulated microgravity (SMG) induced the changes in cell proliferation and cytoskeleton organization, which plays an important factor in various cellular processes. The inhibition in cell cycle progression has been considered to be one of the main causes of proliferation inhibition in cells under SMG, but their mechanisms are still not fully understood. This study aimed to evaluate the effects of SMG on the proliferative ability and cytoskeleton changes of Chang Liver Cells (CCL-13). CCL-13 cells were induced SMG by 3D clinostat for 72 h, while the control group were treated in normal gravity at the same time. The results showed that SMG reduced CCL-13 cell proliferation by an increase in the number of CCL-13 cells in G0/G1 phase. This cell cycle phase arrest of CCL-13 cells was due to a downregulation of cell cycle-related proteins, such as cyclin A1 and A2, cyclin D1, and cyclin-dependent kinase 6 (Cdk6). SMG-exposed CCL-13 cells also exhibited a downregulation of α-tubulin 3 and β-actin which induced the cytoskeleton reorganization. These results suggested that the inhibited proliferation of SMG-exposed CCL-13 cells could be associate with the attenuation of major cell cycle regulators and main cytoskeletal proteins. 相似文献
4.
《Journal of Process Control》2014,24(8):1179-1186
In this paper, we analyze the closed-loop performance of a recently introduced economic model predictive control (MPC) scheme with self-tuning terminal cost. To this end, we propose to use a generalized terminal region constraint instead of a generalized terminal equality constraint within the repeatedly solved optimization problem, which allows us to obtain improved closed-loop asymptotic average performance bounds. In particular, these bounds can be obtained a priori. We discuss how the necessary parameters for the generalized terminal region setting can be calculated, and we illustrate our findings with two numerical examples. 相似文献
5.
两种昆虫生长调节剂——几丁质合成抑制剂和非舀类蜕皮激素类似物虽然都是作用于蜕皮过程,但有着截然不同的作用机制,本文对这两种杀虫剂作用机制的研究进展进行了总结和比较。 相似文献
6.
双闭环控制供水系统采用自整定模糊PID控制算法,以水泵电动机的转速和管网水压为设定参数,实现恒压供水。该系统实时控制性能良好,节能效果显著。 相似文献
7.
Robust Adaptive Soft Landing Control of an Electromagnetic Valve Actuator for Camless Engines 下载免费PDF全文
Paolo Mercorelli 《Asian journal of control》2016,18(4):1299-1312
This paper deals with a signal‐based robust adaptive approximation technique for a proportional derivative (PD) regulator which is applied to an electromagnetic valve actuator control for camless internal combustion engines. PD regulators generate very high spikes in the presence of unavoidable noise. These spikes cause high power dissipation and poor dynamic performance with a lack of precision. The presented method allows the reduction of the noise and not robust nonlinear uncertainties effects by using minimum variance analysis. The technique with which the PD regulator is approximated does not depend on the model of the controlled system. Hence, the technique is quite general and can be applied to any type of system. In addition, this paper describes a feasible real‐time self‐tuning of an approximated discrete PD regulator using a backward Euler technique. The main contribution of the paper is the presentation of an approximated PD controller using a minimum variance control strategy together with a weighted least squares method to adapt the parameters of this approximated controller. This control law realises a robust control technique with respect to the noise and nonlinear uncertainties. Moreover, a comparison with the approximate PD controller proposed in MATLAB by Mathworks is provided. The presented technique ensures a good dynamic performance, including low dissipation as well as accurate positioning and soft landing control. 相似文献
8.
针对工业控制中传统阀门定位器稳定性差、定位精度低、抗干扰能力差、智能化程度低等缺点,以及我国自主研发生产高精度阀门定位器上的不足。设计了以ARM Cortex-M3 内核处理器作为核心控制器的低功耗智能定位阀控制系统。设计中采用优化的PID控制算法,并采用齐格勒-尼克尔斯法则,自整定PID参数。通过二线制HART 协议实现与外界设备通讯。实践证明自整定PID参数能够更好的适应各种控制现场,控制系统能够稳定、快速的运行实现了阀门位置的精确定位和本安低功耗设计的要求。 相似文献
9.
自校正DMC-PID过热汽温控制系统仿真 总被引:1,自引:0,他引:1
为了克服在过热汽温控制中对象参数变化对系统控制带来的困难,提出了自校正DMC-PID控制方法.保留了通常过热汽温控制采用的串级控制结构,能够快速有效地克服干扰.同时通过参数辨识得到非参数模型进行动态矩阵控制(DMC),即自校正DMC,无需从广义对象的阶跃模型的上下界中选取一条标称的阶跃响应曲线去实现DMC控制,实际应用起来更简单.仿真结果表明,控制方法有良好的控制效果,改善了模型失配时的鲁棒性,在过热汽温控制中是十分有效的. 相似文献
10.
Bhattacharya D Saha S Basu S Chakravarty S Chakravarty A Banerjee D Chakrabarti A 《Proteomics. Clinical applications》2010,4(5):480-488
Purpose: In (hemoglobin, Hb) HbEβ‐thalassemia, HbE (β‐26 Glu→Lys) interacts with β‐thalassemia to produce clinical manifestation of varying severity. This is the first proteomic effort to study changes in protein levels of erythrocytes isolated from HbEβ‐thalassemic patients compared to normal. Experimental design: We have used 2‐DE and MALDI‐MS/MS‐based techniques to investigate the differential proteome profiling of membrane and Hb‐depleted fraction of cytosolic proteins of erythrocytes isolated from the peripheral blood samples of HbEβ‐thalassemia patients and normal volunteers. Results: Our study showed that redox regulators such as peroxiredoxin 2, Cu‐Zn superoxide dismutase and thioredoxin and chaperones such as α‐hemoglobin stabilizing protein and HSP‐70 were upregulated in HbEβ‐thalassemia. We have also observed larger amounts of membrane associated globin chains and indications of disruption of spectrin‐based junctional complex in the membrane skeleton of HbEβ‐thalassemic erythrocytes upon detection of low molecular weight fragments of β‐spectrin and decrease in β‐actin and dematin content. Conclusion and clinical relevance: We have observed interesting changes in the proteomic levels of redox regulators and chaperons in the thalassemic hemolysates and have observed strong correlation or association of the extent of such proteomic changes with HbE levels. This could be important in understanding the role of HbE in disease progression and pathophysiology. 相似文献