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如何提高能量转换效率是整个风力发电系统优化控制的关键,因此重点研究并网型风力发电机组控制系统的主控制器,包括功能描述、系统构建、控制参数以及励磁系统控制器等. 相似文献
3.
The control mechanism of mechanical bone remodeling at cellular level was investigated by means of an extensive parametric study on a theoretical model described in this paper. From a perspective of control mechanism, it was found that there are several control mechanisms working simultaneously in bone remodeling which is a complex process. Typically, an extensive parametric study was carried out for investigating model parameter space related to cell differentiation and apoptosis which can describe the fundamental cell lineage behaviors. After analyzing all the combinations of 728 permutations in six model parameters, we have identified a small number of parameter combinations that can lead to physiologically realistic responses which are similar to theoretically idealized physiological responses. The results presented in the work enhanced our understanding on mechanical bone remodeling and the identified control mechanisms can help researchers to develop combined pharmacological-mechanical therapies to treat bone loss diseases such as osteoporosis. 相似文献
4.
研究压电激励圆形曲梁的静态位移响应及位移控制的参数特性。将压电夹层圆形曲梁等效为单层结构,基于一维小曲率曲梁理论,建立其控制方程。在集中弯矩和径向集中力以及电载荷作用下,分析了带压电激励器的圆形悬臂曲梁的静态响应。与有限元结果比较表明:本文的理论模型能够模拟压电激励的小曲率圆形曲梁的静态响应。压电夹层圆形曲梁在任意位置的径向集中力载荷作用下,控制其自由端径向位移响应为零,求得控制电压的解析表达,数值分析表明:随着集中力载荷的位置变化和梁长的变化,最优控制电压将出现峰值和反号。 相似文献
5.
以不同含水量的乙二醇溶液为电解液,采用阳极氧化法制备TiO2纳米管阵列。通过记录反应过程中电导率、粘度及回路电流随时间的变化曲线,研究含水量对电解液粘度、电导率及电流等过程参数的影响,分析了纳米管形貌尺寸与TiO2溶蚀所耗电荷量的关系。粘度初始值和初始电导率均与含水量呈三次关系,相关系数分别为0.992 5和0.977 8。在反应过程中,溶液粘度值有缓慢增加的趋势。由于不同含水量的电解液粘度的不同,H+和OH-数量不同,F-迁移速率不同,电导率-时间曲线及电流-时间曲线具有不同的变化趋势,并对其进行了理论分析。当水体积分数为4%,5%,6%和10%时,纳米管的形貌较为有序并且TiO2纳米管阵列表面的碎片较少,纳米管直径变化范围为50nm至72nm,长度变化范围为0.85~1.90μm。F-腐蚀氧化膜时所消耗电量与TiO2氧化膜被腐蚀掉的体积呈一次函数关系,即腐蚀电量越大,腐蚀掉的体积越大,为制备一定形貌尺寸的纳米管提供了一定的控制方法。 相似文献
6.
As is well known, the exact evolution equation of the curvature perturbation plays a very important role in investigation of the inflaorresponding exacttion power spectrum of the flat universe. However, the c extension for the non-flat universes has not yet been given clearly. Interest in the non-flat, specially closed, universes has been aroused recently. The need for this extension is pressing. We start with the most elementary physical consideration and obtain finally this exact evolution equation of the curvature perturbation for the non-flat universes, as well as the evolutionary controlling parameter and the exact expression of the variable mass in this equation. We approximately perform a primitive and immature analysis on the power spectrum of non-flat universes. This analysis shows that the exact evolution equation of the curvature perturbation for the non-flat universes is very complicated, and we need to carry out many numerical and analytic works for this new equation in the future to judge whether the universe is fiat or closed by comparison of theories with observations. 相似文献
7.
A scheme for probabilistic controlled teleportation of a triplet W state from the sender Alice to the distant receiver Bob is proposed. In this scheme, an m-qubit GHZ state serves as the control parameter. The m control qubits are shared by m(s1, s2… sm) spatially-separated supervisors. With the aid of local operations and individual measurements, including Bell-state measurement, Von Neumann measurement, and mutual classical communication, etc., Bob can faithfully reconstruct the original state by performing relevant unitary transformations. However, even if one participant does not cooperate during the process, the receiver Bob cannot fully recover the original state. This protocol can be extended to probabilistic controlled teleportation of an arbitrary N-qubit state and some other N-qubit entangled states. 相似文献
8.
Dependences of spin polarization on the control parameters in the spin-polarized injection through the magnetic p-n junction 下载免费PDF全文
Effective spin-polarized injection from magnetic semiconductor (MS)
to nonmagnetic semiconductor (NMS) has been highlighted in recent
years. In this paper we study theoretically the dependence of
nonequilibrium spin polarization (NESP) in NMS during spin-polarized
injection through the magnetic p-n junction. Based on the theory in
semiconductor physics, a model is established and the boundary
conditions are determined in the case of no external spin-polarized
injection and low bias. The control parameters that may influence the
NESP in NMS are indicated by calculating the distribution of spin
polarization. They are the doping concentrations, the equilibrium
spin polarization in MS and the bias. The effective spin-polarized
injection can be realized more easily by optimizing the above
parameters. 相似文献
9.
This paper is concerned with the Hopf bifurcation control of a new hyperchaotic circuit system. The stability of the hyperchaotie circuit system depends on a selected control parameter is studied, and the critical value of the system parameter at which Hopf bifurcation occurs is investigated. Theoretical analysis give the stability of the Hopf bifurcation. In particular, washout filter aided feedback controllers are designed for delaying the bifurcation point and ensuring the stability of the bifurcated limit cycles. An important feature of the control laws is that they do not result in any change in the set of equilibria. Computer simulation results are presented to confirm the analytical predictions. 相似文献
10.
江苏广播电视总台电视伴音响度控制技术及政策研究项目小组,从2010年底开始对电视伴音响度的测量及控制进行较为深入地研究。 相似文献