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991.
Summary Via new perspectives, for the time dimension, the present exposition overviews new and recent advances describing a standardized
formal theory towards the evolution, classification, characterization and generic design of time discretized operators for
transient/dynamic applications. Of fundamental importance in the present exposition are the developments encompassing the
evolution of time discretized operators leading to the theoretical design of computational algorithms and their subsequent
classification and characterization. And, the overall developments are new and significantly different from the way traditional
modal type and a wide variety of step-by-step time marching approaches which we are mostly familiar with have been developed
and described in the research literature and in standard text books over the years. The theoretical ideas and basis towards
the evolution of a generalized methodology and formulations emanate under the umbrella and framework and are explained via
a generalized time weighted philosophy encompassing the semi-discretized equations pertinent to transient/dynamic systems.
It is herein hypothesized that integral operators and the associated representations and a wide variety of the so-called integration
operators pertain to and emanate from the same family, with the burden which is being carried by a virtual field or weighted
time field specifically introduced for the time discretization is strictly enacted in a mathematically consistent manner so
as to first permit obtaining the adjoint operator of the original semi-discretized equation system. Subsequently, the selection
or burden carried by the virtual or weighted time fields originally introduced to facilitate the time discretization process
determines the formal development and outcome of “exact integral operators”, “approximate integral operators”, including providing
avenues leading to the design of new computational algorithms which have not been exploited and/or explored to-date and the
recovery of most of the existing algorithms, and also bridging the relationships systematically leading to the evolution of
a wide variety of “integration operators”. Thus, the overall developments not only serve as a prelude towards the formal developments
for “exact integral operators”, but also demonstrate that the resulting “approximate integral operators” and a wide variety
of “new and existing integration operators and known methods” are simply subsets of the generalizations of a standardizedW
p
-Family, and emanate from the principles presented herein. The developments first leading to integral operators in time, and
the resulting consequences then systematically leading to not only providing new avenues but additionally also explaining
a wide variety of generalized integration operators in time of which single-step time integration operators and various widely
recognized algorithms which we are familiar are simply subsets, the associated multi-step time integration operators, and
a class of finite element in time integration operators, and their relationships are particularly addressed. The theoretical
design developments encompass and explain a variety of time discretized operators, the recovery of various original methods
of algorithmic development, and the development of new computational algorithms which have not been exploited and/or explored
to-date, and furthermore, permit time discretized operators to be uniquely classified and characterized by algorithmic markers.
The resulting and so-called discrete numerically assigned [DNA] algorithmic markers not only serve as a prelude towards providing
a standardized formal theory of development of time discretized operators and forum for selecting and identifying time discretized
operators, but also permit lucid communication when referring to various time discretized operators. That which constitutes
characterization of time discretized operators are the so-called DNA algorithmic markers which essentially comprise of both:
(i) the weighted time fields introduced for enacting the time discretization process, and (ii) the corresponding conditions
(if any) these weighted time fields impose (dictate) upon the approximations for the dependent field variables and updates
in the theoretical development of time discretized operators. As such, recent advances encompassing the theoretical design
and development of computational algorithms for transient/dynamic analysis of time dependent phenomenon encountered in engineering,
mathematical and physical sciences are overviewed. 相似文献
992.
在对Matlab外部编程接口的分析基础上,本文用ATL技术实现了一个ActiveX控件集成了对Matlab引擎的访问。并给出了实现过程及主要源码。最后介绍了组件对象模型的基本思想。 相似文献
993.
介绍球磨机的结构和工作机理,指出球磨机存在的问题,并对其轴封、轴头、进气口、吸料口等进行了技改,以提高设备的运行周期,满足生产需求。 相似文献
994.
995.
996.
四川省平武县宝灵寺水电站建设期在2007年,受到当时国内灯泡式水轮机选型理念及技术水平的限制,机组选型偏保守。本次增容改造主要目的是在不改变现有流道及转轮直径的情况下,机组出力由12MW增容到14MW。本文对水轮机出力、吸出高度、机组运行稳定性等方面进行了详细的分析、计算,为电站增容改造的实施提供了理论依据,对灯泡贯流式水轮机组的选型、计算提供了借鉴经验。 相似文献
997.
Rui Wu Jinhai Xu Chong Li Baojing Zhou Qianqian Ma Zhongliang Wang 《矿业科学技术学报(英文版)》2012,22(4):567-571
A test method for the non-destructive determination of bolt length, anchoring length, and bolt body force is described. This addresses the problems of low accuracy, limited number of data, and untimely warning signs encountered with existing test methods. Numerical simulations of the bolt, resin, and rock system show that the length accuracy when using the velocity wave is lower than when using the acceleration wave. It is accepted practice to use the acceleration wave for length tests because of improved signal to noise ratios of the waveforms. Laboratory and in situ underground tests showed that the precision of the measurements meets field requirements. Using this method the anchor properties of each single bolt and, thus, the safety of the entire roadway support may be evaluated. 相似文献
998.
In the construction of the filling gob-side entry retaining in a lane, we utilize the self-slide natural phenomenon of a falling gangue in an inclined coal seam goaf. First, we put the falling gangue of goaf above the laneway and made it the main filling material by adopting the measurement of flexible supporting system combined with those of rigid supporting system. Then we made the filling material gunited and solidified to maintain the filling goal of the gob-side entry retaining beside the lane. Considering the law of energy conservation and law of pressure distribution for retaining the active and static soil of the wall, we analyzed the reliability of a gangue blocking facilities and the stability of the filling material in the lane. We analyze the figures to see the stability. The result shows that the gangue block supporting system is reliable, and has been successfully practically applied. 相似文献
999.
This paper is concerned with the guaranteed cost control for continuous-time singular Markovian jump systems with time-varying delay. Without using the free weighting matrices method, a delay-range-dependent condition is derived in terms of strict linear matrix inequality (LMI), which guarantees that the singular system is regular, impulse free and mean-square exponentially stable with an H(∞) performance. Based on this, the existence condition of the guaranteed cost state feedback controller is proposed. A numerical example is given to illustrate the effectiveness and less conservatism of the proposed design method. 相似文献
1000.