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排序方式: 共有1449条查询结果,搜索用时 15 毫秒
91.
Design of satisfaction output feedback controls for stochastic nonlinear systems under quadratic tracking risk-sensitive index 总被引:5,自引:0,他引:5
In this paper, the design problem of satisfaction output feedback controls for stochastic nonlinear systems in strict feedback form under long-term tracking risk-sensitive index is investigated. The index function adopted here is of quadratic form usually encountered in practice, rather than of quartic one used to beg the essential difficulty on controller design and performance analysis of the closed-loop systems. For any given risk-sensitive parameter and desired index value, by using the integrator backstepping method, an output feedback control is constructively designed so that the closed-loop system is bounded in probability and the risk-sensitive index is upper bounded by the desired value. 相似文献
92.
The saturation activity of residual nuclei was estimated based on measurements when 2.5 GeV electron beams were totally absorbed in thick Al, Fe, Cu and Pb. A calculation was also made for a beam dump from 0.1 to 10 GeV using the EGS4 and PICA95 Monte Carlo codes. Above 1 GeV, the activity was constant in units of MBq.W-1. The gamma ray dose rates from the targets were calculated using these data. 相似文献
93.
卧式离心机托轮旋转时,通过摩擦力把运动传递给了冷型,在托轮的带动下,冷型按一定的角速度旋转.本文探讨了冷型在离心铸造过程中产生振动的原因,提出了减小和防止冷型在离心过程中振动的方法. 相似文献
94.
Yungang LI ) Jie LI ) Kuai ZHANG ) Limin LIU ) ) College of Metallurgy & Energy Hebei United University Tangshan China ) Key Laboratory of Metastable Materials Science & Technology Yanshan University Qinhuangdao China ) Qinggong College China 《金属学报(英文版)》2011,(6)
The electrochemical reaction mechanism and electrocrystallization process of Cu on copper electrode in the eutectic NaCl-KCl-CuCl molten salt were investigated by means of cyclic voltammetry, chronopotentiometry and chronoamperometry technique at 710 C. The results show that the electrochemical reaction process of Cu is a quasi-reversible process mix-controlled by Cu + diffusion rate and electron transport rate; the electrochemical reduction mechanism is Cu + +e→Cu; the electrocry stallization process of co... 相似文献
95.
Jian Zhang Yungang Liu 《International Journal of Adaptive Control and Signal Processing》2013,27(5):368-385
This paper is concerned with the globally stabilizing control design for a class of high‐order nonholonomic systems. Compared with the existing literature, the high‐order nonholonomic systems under investigations have more uncertainties and unknowns, such as neither lower nor upper bound is known for each control coefficient of the systems. This renders the existing control methods highly difficult to the control problems of the systems or even inapplicable. In this paper, by defining two new unknown parameters whose dynamic updating laws are properly chosen and also by using the discontinuous coordinates transformation and the method of adding a power integrator, a new design approach is given to the adaptive stabilizing controllers for the systems. A numerical simulation is provided to demonstrate the effectiveness of the theoretical results. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
96.
97.
Junhyeong Ban Kijung Kim Hyejun Jung Soonja Choe 《Journal of Industrial and Engineering Chemistry》2010,16(6):246-1049
The polystyrene spherical particles with homogeneously distributed magnetites were prepared using the conventional miniemulsion polymerization. In the first, the magnetite nanoparticles were coated with oleic acid in aqueous Fe3+/Fe2+ solution using excess ammonium hydroxide via co-precipitation method. In the second, the miniemulsion polymerization of styrene was carried out using various concentrations of potassium persulfate (KPS) as an initiator, H-08E as an emulsifier, hexadecane as a co-emulsifier and acrylic acid as a dispersing agent in the presence of oleic acid coated magnetite at 70 °C for 24 h. The particle size and its distribution of the homogeneously embedded magnetites were influenced by the concentration of the initiator (KPS) and acrylic acid (AAc). In addition, the emulsifier, H-08E, affects the size and the shape of the PS particles. The optimum conditions for the homogeneously distributed magnetite in the spherical PS particles with the narrow distribution were 5 wt.% styrene, 0.2 g KPS, 0.2 g AAc, and 0.12 g H-08E by inducing 364 nm in diameter, 12.04% in the coefficient of variation (Cv) and 22.1% of the maximum magnetite content. 相似文献
98.
99.
��������������湤�ռ��� 总被引:1,自引:2,他引:1
牙哈凝析气田位于新疆维吾尔自治区牙哈县境内,是目前已开发的国内陆上储量最大、压力最高的高产凝析气田,也是第一个采用循环注气保持地层压力开采的整装凝析气田。具有油藏流体类型复杂、埋藏深(5000 m以上)、地层压力高(50 MPa) 等特点。在说明了牙哈气田所具有的单井产量高、井口压力高、油气比高、井口温度低、凝析油含蜡量高等特点后,简要地介绍了牙哈凝析气田地面工艺中高压注气、凝析气集输和凝析气处理等技术。经过3年多运转实践表明,牙哈凝析气田地面工艺技术简单、实用、经济、可靠,并取得了巨大的经济效益和社会效益。 相似文献
100.