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41.
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43.
Information systems (IS) integration is among the most challenging tasks in corporate mergers and acquisitions (M&As). In
this paper we propose and illustrate the use of an approach to analyzing and planning post-merger IS integration that extends
general theory for IS planning, considering the specific characteristics of the M&A context. We highlight that planning effectiveness
is possible to achieve in fundamentally different ways, dependent on the characteristics of the merger or acquisition at hand.
相似文献
Stefan HenningssonEmail: |
44.
Optimizing multiple dimensional queries simultaneously in multidimensional databases 总被引:1,自引:0,他引:1
Weifa Liang Maria E. Orlowska Jeffrey X. Yu 《The VLDB Journal The International Journal on Very Large Data Bases》2000,8(3-4):319-338
Some significant progress related to multidimensional data analysis has been achieved in the past few years, including the
design of fast algorithms for computing datacubes, selecting some precomputed group-bys to materialize, and designing efficient
storage structures for multidimensional data. However, little work has been carried out on multidimensional query optimization
issues. Particularly the response time (or evaluation cost) for answering several related dimensional queries simultaneously
is crucial to the OLAP applications. Recently, Zhao et al. first exploited this problem by presenting three heuristic algorithms.
In this paper we first consider in detail two cases of the problem in which all the queries are either hash-based star joins
or index-based star joins only. In the case of the hash-based star join, we devise a polynomial approximation algorithm which
delivers a plan whose evaluation cost is $ O(n^{\epsilon }$) times the optimal, where n is the number of queries and is a fixed constant with . We also present an exponential algorithm which delivers a plan with the optimal evaluation cost. In the case of the index-based
star join, we present a heuristic algorithm which delivers a plan whose evaluation cost is n times the optimal, and an exponential algorithm which delivers a plan with the optimal evaluation cost. We then consider
a general case in which both hash-based star-join and index-based star-join queries are included. For this case, we give a
possible improvement on the work of Zhao et al., based on an analysis of their solutions. We also develop another heuristic
and an exact algorithm for the problem. We finally conduct a performance study by implementing our algorithms. The experimental
results demonstrate that the solutions delivered for the restricted cases are always within two times of the optimal, which
confirms our theoretical upper bounds. Actually these experiments produce much better results than our theoretical estimates.
To the best of our knowledge, this is the only development of polynomial algorithms for the first two cases which are able
to deliver plans with deterministic performance guarantees in terms of the qualities of the plans generated. The previous
approaches including that of [ZDNS98] may generate a feasible plan for the problem in these two cases, but they do not provide
any performance guarantee, i.e., the plans generated by their algorithms can be arbitrarily far from the optimal one.
Received: July 21, 1998 / Accepted: August 26, 1999 相似文献
45.
It is argued that robotic platforms are the way forward towards building intelligent systems, where multiple sensors and manipulation are used for cognitive processes. It is also argued that the cue for developing the right architecture for such a system is human language. 相似文献
46.
47.
Comments on the paper by Mosig (IEEE Antennas and Propagation Magazine, vol.47, p.38-40, 2005 December). The paper by Mosig discussed acceleration of convergence of series. Without commenting on either the validity or efficiency of his method, the present author would like to draw attention to an existing method, published long ago by D. Shanks (1955). Briefly stated, this method takes a sequence and defines partial sums, which is described in this paper. 相似文献
48.
Software release management is the process through which software is made available to and obtained by its users. Until now, this process has been relatively straightforward. However, the emergence of component‐based software is complicating software release management. Increasingly, software is constructed via the assembly of pre‐existing, independently produced, and independently released components. Both developers and users of such software are affected by these complications. Developers need to accurately document the complex and changing dependencies among the components constituting the software. Users must be involved in locating, retrieving, and assembling components in order to appropriately bring the software into their particular environment. In this paper, we introduce the problem of release management for component‐based software and discuss SRM, a prototype software release management tool we have developed that supports both developers and users in the software release management process. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
49.
Developers often call an embedded system's hardware architecture a platform. The idea is that you select a hardware platform, then write software to fit onto it. Matters are, however, more complicated. The platform provides the computing resources required to run the embedded application, and the decisions about what hardware should go into the platform often depend on what sort of software you want to run. It is predicted that constant pressure on the cost and power consumption of embedded systems will continue to spawn a diversity of uniprocessor and multiprocessor platforms. 相似文献
50.
Lippert M. Becker-Pecbau P. Breitling H. Koch J. Kornstadt A. Roock S. Schmolitzky A. Wolf H. Zullighoven H. 《Computer》2003,36(6):67-73
Using methodological extensions to adapt extreme programming (XP) for major projects offers a high security and reliability without limiting software development's advantages. The authors describe their use of XP extensions that focus on development's planning and controlling aspects, demonstrating that a suitably adapted agile development process is applicable to long-term, large-system projects. 相似文献