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971.
972.
研究了正态分布下(?)图与抽样资源分配方式之间的关系。结果表明高抽样率并不是控制图高效的必要条件,其效率还大大依赖于抽样资源分配方式。基于统计性质和平均质量损失,不管是控制图的初始表现,稳态表现还是优化结果,均显示在抽样率固定下,要想快速发现过程均值大的飘移量或期望值大的随机飘移量,应该频繁采集小容量的样本;而对于过程均值小的飘移量或期望值小的随机飘移量,高效方式为在大抽样间隔下采集大容量样本。 相似文献
973.
A new optimal control problem that incorporates the residual of the Eikonal equation into its objective is presented. The formulation of the state equation is based on the level set transport equation but extended by an additional source term, correcting the solution so as to minimize the objective functional. The method enforces the constraint so that the interface cannot be displaced at least in the continuous setting. The system of first‐order optimality conditions is derived, linearized, and solved numerically. The control also prevents numerical instabilities, so that no additional stabilization techniques are required. This approach offers the flexibility to include other desired design criteria into the objective functional. The methodology is evaluated numerically in three different examples and compared with other PDE‐based reinitialization techniques. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
974.
975.
In this Letter, a novel method is developed for generating grid multi-scroll chaotic attractors using switching piecewise linear controller. First, a third-order linear system is designed to ensure that its unique equilibrium point belongs to a saddle-focus type with index 2 and the corresponding eigenvalues satisfy Shilnikov conditions. Then, by three different types of switching control strategies, the equilibrium point can be extended along both xy plane and z axis direction, so as to generate grid multi-scroll chaotic attractors. The dynamical behaviors are further analyzed. Moreover, an improved module-based circuit is designed for realizing 5×3 and 4×4 grid scroll chaotic attractors, and the experimental results are also obtained, which is consistent with the numerical simulations. 相似文献
976.
Synchronization of different chaotic systems via active radial basis functions sliding mode controller
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This paper presents a new method to synchronize different chaotic systems with disturbances via an active radial basis function (RBF) sliding controller. This method incorporates the advantages of active control, neural network and sliding mode control. The main part of the controller is given based on the output of the RBF neural networks and the weights of these single layer networks are tuned on-line based on the sliding mode reaching law. Only several radial basis functions are required for this controller which takes the sliding mode variable as the only input. The proposed controller can make the synchronization error converge to zero quickly and can overcome external disturbances. Analysis of the stability for the controller is carried out based on the Lyapunov stability theorem. Finally, five examples are given to illustrate the robustness and effectiveness of the proposed synchronization control strategy. 相似文献
977.
A whole impulsive control scheme of nonlinear systems with time-varying delays, which is an extension for impulsive control of nonlinear systems without time delay, is presented in this paper. Utilizing the Lyapunov functions and the impulsive-type comparison principles, we establish a series of different conditions under which impulsively controlled nonlinear systems with time-varying delays are asymptotically stable. Then we estimate upper bounds of impulse interval and time-varying delays for asymptotically stable control. Finally a numerical example is given to illustrate the effectiveness of the method. 相似文献
978.
We propose an impulsive hybrid control method to control the
period-doubling bifurcations and stabilize unstable periodic orbits
embedded in a chaotic attractor of a small-world network. Simulation
results show that the bifurcations can be delayed or completely
eliminated. A periodic orbit of the system can be controlled to any
desired periodic orbit by using this method. 相似文献
979.
The performance of synchronous reluctance motor (SynRM) degrades due to chaos when its systemic parameters fall into a certain area. To control the undesirable chaos in SynRM, a passive control law is presented in this paper, which transforms the chaotic SynRM into an equivalent passive system. It is proved that the equivalent system can be asymptotically stabilized at the set equilibrium point, namely, chaos in SynRM can be controlled. Moreover, in order to eliminate the influence of undeterministic parameters, an adaptive law is introduced into the designed controller. Computer simulation results show that the proposed controller is very effective and robust against the uncertainties in systemic parameters. The present study may help to maintain the secure operation of industrial servo drive system. 相似文献
980.
This paper firstly introduces the control methods to fractals and give the definition of synchronization of Julia sets between two different systems. Especially, the gradient control method is taken on the classic Julia sets of complex quadratic polynomial Zn+1 = zn^2+ c, which realizes its Julia sets control and synchronization. The simulations illustrate the effectiveness of the method. 相似文献