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991.
Xiefu Jiang Qing-Long Han Shirong Liu Anke Xue 《Automatic Control, IEEE Transactions on》2008,53(4):1025-1032
This note is concerned with robust Hinfin control of linear networked control systems with time-varying network-induced delay and data packet dropout. A new Lyapunov-Krasovskii functional, which makes use of the information of both the lower and upper bounds of the time-varying network-induced delay, is proposed to drive a new delay-dependent Hinfin stabilization criterion. The criterion is formulated in the form of a non-convex matrix inequality, of which a feasible solution can be obtained by solving a minimization problem in terms of linear matrix inequalities. In order to obtain much less conservative results, a tighter bounding for some term is estimated. Moreover, no slack variable is introduced. Finally, two numerical examples are given to show the effectiveness of the proposed design method. 相似文献
992.
The influence of wall charge distribution on the time lag of address discharge in an AC plasma display panel is investigated using two different reset waveforms: one (typical reset) induces both face and surface discharges and the other (TR reset) induces face discharges only. The measured formative time lag and statistical time lag of address discharge for TR were 21–31 ns and 31–74 ns shorter than the one for the typical reset, respectively. The TR reset resulted in much less increase of statistical time lag than the typical reset when the reset-to-address time interval was increased, and 70 ns smaller deviation of the statistical time lag among different color cells. Calculations show that the TR reset forms a much smoother wall charge profile, which is less susceptible to cell parameter variations, than the typical reset. The observed differences in the time lags of address discharge between different scan lines and color cells are strongly correlated to the differences of the wall charge profile, indicating that a smooth wall charge profile formed by the reset using face discharges only reduces the time lag of address discharge and minimizes the susceptibility of address discharge to cell parameter variation. 相似文献
993.
Motion synthesis with decoupled parameterization 总被引:2,自引:0,他引:2
In real-time animation systems, motion interpolation techniques are widely used for their controllability and efficiency. The techniques sample the parameter space using example motions, and interpolate them to compute the blend weights corresponding to the given parameters. A main problem of the techniques is that, as the dimension n of the parameter space increases, the number of required example motions increases exponentially, i.e. O(c n ). To resolve the problem, this paper proposes to use two decoupled parameter spaces for controlling the upper body and the lower body separately. At each frame time, a parameterized motion space produces a source frame, and the target frame is synthesized by splicing the upper body of one source frame with the lower body of the other. In order to have the two source frames correlated with each other, a time-warping scheme has been developed. Furthermore, in order to handle the dynamic properties of the parameter samples of the upper body, we have developed an approximation technique for quickly determining the sample positions in its parameter space. This decoupled parameterization method alleviates the complexity problem, e.g. from O(c 6) to O(c 3), while providing the users with the capability of convenient control over the character. 相似文献
994.
A new approach to the design of a neural network (NN) based navigator is proposed in which the mobile robot travels to a pre-defined
goal position safely and efficiently without any prior map of the environment. This navigator can be optimized for any user-defined
objective function through the use of an evolutionary algorithm. The motivation of this research is to develop an efficient
methodology for general goal-directed navigation in generic indoor environments as opposed to learning specialized primitive
behaviors in a limited environment. To this end, a modular NN has been employed to achieve the necessary generalization capability
across a variety of indoor environments. Herein, each NN module takes charge of navigating in a specialized local environment,
which is the result of decomposing the whole path into a sequence of local paths through clustering of all the possible environments.
We verify the efficacy of the proposed algorithm over a variety of both simulated and real unstructured indoor environments
using our autonomous mobile robot platform. 相似文献
995.
Collapse-free thermal bonding technique for large area microchambers in plastic lab-on-a-chip applications 总被引:1,自引:0,他引:1
Dong Sung Kim Hyun Sup Lee Jungyoup Han Se Hwan Lee Chong H. Ahn Tai Hun Kwon 《Microsystem Technologies》2008,14(2):179-184
Bonding is an essential step to form microchannels or microchambers in lab-on-a-chip applications. In this paper, we present
a novel plastic thermal bonding technique to seal and form large area microchambers (planar characteristic width and length
on the order of 1 mm and characteristic thickness on the order of 10–100 μm) without collapse by introducing a holed pressure
equalizing plate (HPEP) that includes holes of the same size and shape as the microchambers. To demonstrate the proposed technique,
two types of large area microchambers [(1) 20 × 10 mm and 40 μm thick and (2) 12 × 2.5 mm and 120 μm thick] with microchannels
were designed and replicated on plastic substrates by means of hot embossing and injection molding processes with prepared
two nickel mold inserts. The replicated large area microchambers as well as the microchannels in the plastic lab-on-a-chip
were successfully sealed (i.e., no leakage) and formed without any collapse by the proposed thermal bonding technique with
the help of the HPEP. 相似文献
996.
现场总线的发电厂机组控制应用研究 总被引:2,自引:2,他引:0
论述了国内外火电厂目前现场总线的应用状况,并针对机组控制特点,对火电厂在现场设备层采用现场总线系统的配置、设计原则、注意事项进行了分析.通过技术及经济上的比较得出,应用现场总线技术将带来全厂管控数字化和全生命周期的设计、安装、调试、运行维护成本节省等有利因素,可在机组现场设备层面逐步推广采用现场总线技术. 相似文献
997.
当前处理器由于较高的能量消耗,导致处理器热量散发的提高及系统可靠性的降低,同时任务实际运行中的错误也降低了系统的可靠性.因此同时满足节能性及容错性已经成为目前计算机领域较为关心的问题.提出的调度算法针对实时多处理器计算环境,以执行时间最短的任务优先调度为基础,结合其他有效技术(共享空闲时间回收及检查点技术),使得实时任务在其截止期内完成的同时,能够动态地降低整个系统的能量消耗及动态容错.针对独立任务集及具有依赖关系的任务集,提出两种算法:STFBA1及STFBA2(shortest task first based algorithm).通过实验与目前所知的有效算法相比,算法具有更好的性能(调度长度及能量消耗)及较低的通信时间复杂度. 相似文献
998.
基于角色的访问控制近年来得到了广泛的研究与发展。提出了一个引入空间特性的角色访问控制模型,在模型中对原有授权约束添加了空间特性,并提出了相应算法解决了空间授权约束和会话的状态转变问题。 相似文献
999.
基于随机化的数据扰乱及重构技术是数据挖掘中的隐私保护(Privacy-Preserving Data Mining,PPDM)领域中最重要的方法之一.但是,随机化难以消除由于属性变量本身相关性引起的数据泄漏.介绍了一种利用主成分分析(Principal Component Analysis,PCA)进行属性精简的增强随机化方法,降低了参与数据挖掘的属性数据间相关性,更好地保护了隐私数据. 相似文献
1000.
林涵 《数字社区&智能家居》2009,(35)
在多媒体课件创作中,准备多媒体素材是非常重要的环节。多媒体素材包括文字、图像、图形、动画、声音、影像等。在这几类素材中,图形图像是多媒体课件中应用最基本、最重要和最多的材料,其处理与加工也最为复杂,以下针对这一问题进行探讨。 相似文献