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991.
Graph visualization has been widely used to understand and present both global structural and local adjacency information in relational data sets (e.g., transportation networks, citation networks, or social networks). Graphs with dense edges, however, are difficult to visualize because fast layout and good clarity are not always easily achieved. When the number of edges is large, edge bundling can be used to improve the clarity, but in many cases, the edges could be still too cluttered to permit correct interpretation of the relations between nodes. In this paper, we present an ambiguity-free edge-bundling method especially for improving local detailed view of a complex graph. Our method makes more efficient use of display space and supports detail-on-demand viewing through an interactive interface. We demonstrate the effectiveness of our method with public coauthorship network data.  相似文献   
992.
Influence maximization, defined by Kempe et al. (SIGKDD 2003), is the problem of finding a small set of seed nodes in a social network that maximizes the spread of influence under certain influence cascade models. The scalability of influence maximization is a key factor for enabling prevalent viral marketing in large-scale online social networks. Prior solutions, such as the greedy algorithm of Kempe et al. (SIGKDD 2003) and its improvements are slow and not scalable, while other heuristic algorithms do not provide consistently good performance on influence spreads. In this article, we design a new heuristic algorithm that is easily scalable to millions of nodes and edges in our experiments. Our algorithm has a simple tunable parameter for users to control the balance between the running time and the influence spread of the algorithm. Our results from extensive simulations on several real-world and synthetic networks demonstrate that our algorithm is currently the best scalable solution to the influence maximization problem: (a) our algorithm scales beyond million-sized graphs where the greedy algorithm becomes infeasible, and (b) in all size ranges, our algorithm performs consistently well in influence spread—it is always among the best algorithms, and in most cases it significantly outperforms all other scalable heuristics to as much as 100–260% increase in influence spread.  相似文献   
993.
This paper reports an experimental and numerical investigation on the scaling effects in the flow hydrodynamics for confined microdroplets induced by a surface acoustic wave (SAW). The characteristic parameters of the flow hydrodynamics were studied as a function of the separation height, H, between the LiNbO3 substrate and a top glass plate, for various droplets volumes and radio-frequency powers. The ratio of the gap height to attenuation length of the SAW, H/l SAW, is shown to be an important parameter affecting the streaming flow induced in this confined regime. The reported numerical and experimental results are in good agreement over the range examined in this study and demonstrate that, at a lower gap heights of H?≤?100?μm, a significant decrease in streaming velocity or Reynolds number is induced, with the velocity approaching zero when the gap height is decreased to ~50?μm. An increase in the gap height results in an increased streaming velocity; however, if the gap height exceeds 70?% of the SAW attenuation length, any further increase in the gap height induces a drop in the streaming velocity.  相似文献   
994.
Data corruption in SCADA systems refers to errors that occur during acquisition, processing, or transmission, introducing unintended changes to the original data. In SCADA-based power systems, the data gathered by remote terminal units (RTUs) is subject to data corruption due to noise interference or lack of calibration. In this study, an effective approach based on the fusion of the general regression neural network (GRNN) and the particle swarm optimization (PSO) technique is employed to deal with errors in RTU data. The proposed hybrid model, denoted as GRNN-PSO, is able to handle noisy data in a fast speed, which makes it feasible for practical applications. Experimental results show the GRNN-PSO model has better performance in removing the unintended changes to the original data compared with existing methods.  相似文献   
995.
The electrical resistivity, ac susceptibility, critical current density, and Josephson tunneling of Pb/Ag multilayers have been measured in wide temperature ranges in order to study the proximity effect. A resistivity drop was found to occur atT c of Pb in versusT measurement and, at low temperature, the multilayers show proximity effect. The I-V characteristic of the multilayer shows voltage steps, indicating a resistive state has occurred in the sample. The superconducting properties of the multilayer were analyzed with the bilayer theory of the proximity effect.  相似文献   
996.
The equilibrium Ca3P2(s) = 3[Ca] + 2[P] was studied at 1600 ° by equilibrating liquid iron, saturated with Ca3P2, and contained in a TiN crucible, with Ca vapor. The source of Ca was liquid Ca contained in an Mo crucible, and the vapor pressure of Ca was varied by varying the position of the Mo crucible in the temperature gradient of a vertical tube furnace. A least-squares analysis of the data gave and. The simultaneous equilibria CaO(s) = [Ca] + [O] and CaS(s) = [Ca] + [S] were studied at 1600 ° by equilibrating liquid iron, contained in a pressed and sintered CaO-CaS crucible with Ca vapor. The advantage of this technique is that two equilibrium constants,K cas andK cao, and two interaction coefficients, and can be determined from one set of experiments. It was determined that, at 1600 °,K cas = 5.9 × 10−8 K cao = 5.5 × 10−9,, and. Formerly Graduate Students  相似文献   
997.
用于VLSI的SiO_xN_y薄膜的界面陷阱   总被引:3,自引:1,他引:2  
采用雪崩热电子注入技术研究了用于VLSI的快速热氮化的SiO_xN_y薄膜界面陷阱。给出这种薄介质膜禁带中央界面陷阱密度随氮化时间的变化关系,观察到这种薄膜存在着不同类型的密度悬殊很大的电子陷阱。指出雪崩热电子注入过程中在Si/SiO_xN_y界面上产生两类性质不同的快界面态陷阱,并给出这两种陷阱在禁带中能级位置及密度大小关系;同时还给出禁带中央界面陷阱密度随雪崩注入剂量呈现弱“N”形变化关系,并对实验结果进行了讨论。  相似文献   
998.
The shear stress distribution for the notch problem of plane elasticity in the sliding mode case is investigated in this paper. Particular features of the shear stress distribution beneath the crown point of notch are analyzed by means of the Muskhelishvili method [1]. It is found that the maximum shear stress xy, max is always reached at some point below the surface of the notch. The smaller the radius of the notch, the larger is the maximum shear stress xy, max. A relation between xy, max and stress intensity factor K II of the corresponding crack problem is found to be Several specific examples are given to prove the validity of the obtained relation.% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqefm0B1jxALjhiov2D% aebbfv3ySLgzGueE0jxyaibaiGc9yrFr0xXdbba91rFfpec8Eeeu0x% Xdbba9frFj0-OqFfea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs% 0dXdbPYxe9vr0-vr0-vqpWqaaeaabiGaciaacaqabeaadaqaaqGaaO% qaaiaadUeadaWgaaWcbaGaaeysaiaabMeaaeqaaOGaeyypa0ZaaSaa% aeaacaaIZaWaaOaaaeaacaaIZaGaeqiWdahaleqaaaGcbaGaaGOmaa% aadaWfqaqaaiGacYgacaGGPbGaaiyBaaWcbaGaeqyWdiNaeyOKH4Qa% aGimaaqabaGcdaGcaaqaaiabeg8aYjabeo8aZbWcbeaakmaaBaaale% aacaWG4bGaamyEaiaacYcaciGGTbGaaiyyaiaacIhadaahaaadbeqa% amXvP5wqonvsaeHbuLwBLnhiov2DGi1BTfMBG0evGueE0jxyGi0BSr% gaiuaacqWFUaGlaaaaleqaaaaa!6261!\[K_{{\text{II}}} = \frac{{3\sqrt {3\pi } }}{2}\mathop {\lim }\limits_{\rho \to 0} \sqrt {\rho \sigma } _{xy,\max ^. } \]This research project is supported by the National Science Foundation of China.  相似文献   
999.
陈刚 《办公自动化》2012,(24):26-27,47
基于视觉的疲劳驾驶检测技术是疲劳检测领域的前沿技术。根据基于视觉的车载驾驶员疲劳检测系统实时、小型化、非接触、可扩展等技术要求,以ARM开发板和嵌入式Linux操作系统为平台,设计了一套基于PERCLOS疲劳驾驶检测方法,与传统的基于PC机的疲劳检测系统相比,具有更好的稳定性、可行性以及更优越的可扩充性。  相似文献   
1000.
针对一般方法推导离散系统闭环脉冲传递函数过程繁琐费时的问题,给出一种先连续化求出闭环传递函数再离散化求解的简便方法,并给出使用本方法的单一化条件。对于满足该条件的系统,可直接求用简便方法求取系统的闭环脉冲传递函数,不满足该使用条件的系统,对其中间变量的求取可使用本方法,因而大大简化求解闭环脉冲传递函数的过程,为采样控制系统的分析和设计提供了很大的方便。  相似文献   
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