全文获取类型
收费全文 | 5517篇 |
免费 | 259篇 |
国内免费 | 223篇 |
专业分类
电工技术 | 434篇 |
综合类 | 512篇 |
化学工业 | 137篇 |
金属工艺 | 95篇 |
机械仪表 | 469篇 |
建筑科学 | 582篇 |
矿业工程 | 152篇 |
能源动力 | 64篇 |
轻工业 | 155篇 |
水利工程 | 111篇 |
石油天然气 | 102篇 |
武器工业 | 22篇 |
无线电 | 658篇 |
一般工业技术 | 318篇 |
冶金工业 | 308篇 |
原子能技术 | 14篇 |
自动化技术 | 1866篇 |
出版年
2024年 | 6篇 |
2023年 | 28篇 |
2022年 | 44篇 |
2021年 | 99篇 |
2020年 | 100篇 |
2019年 | 64篇 |
2018年 | 45篇 |
2017年 | 103篇 |
2016年 | 112篇 |
2015年 | 157篇 |
2014年 | 379篇 |
2013年 | 335篇 |
2012年 | 371篇 |
2011年 | 473篇 |
2010年 | 403篇 |
2009年 | 372篇 |
2008年 | 354篇 |
2007年 | 414篇 |
2006年 | 428篇 |
2005年 | 345篇 |
2004年 | 321篇 |
2003年 | 285篇 |
2002年 | 211篇 |
2001年 | 136篇 |
2000年 | 93篇 |
1999年 | 55篇 |
1998年 | 46篇 |
1997年 | 34篇 |
1996年 | 25篇 |
1995年 | 24篇 |
1994年 | 23篇 |
1993年 | 12篇 |
1992年 | 10篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 10篇 |
1988年 | 7篇 |
1987年 | 8篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 7篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1979年 | 7篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1973年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有5999条查询结果,搜索用时 0 毫秒
1.
Competition forces manufacturing systems to be flexible and to increase product variety and process complexity. These tasks depend on the flexible design of a bill of materials (BOM), one of the most important inputs in manufacturing planning and control systems. Product variety forces systems to generate BOMs with regard to product properties through a BOM pattern. A variant bill of materials provides a structure to manage product variability. In this study, an algorithm is designed to build a BOM pattern using computer-aided design and computer-aided manufacturing (CAD/CAM) data, and another algorithm is designed to generate variants with regard to product specifications. Genetic algorithm is used to generate new products to provide high product variability for testing algorithms. After the test, both algorithms are applied to a real industry problem. The BOM pattern is built automatically using CAD/CAM data, and variants are generated with regard to the pattern, and the results are discussed. 相似文献
2.
An organization requires performing readiness-relevant activities to ensure successful implementation of an enterprise resource planning (ERP) system. This paper develops a novel approach to managing these interrelated activities to get ready for implementing an ERP system. The approach enables an organization to evaluate its ERP implementation readiness by assessing the degree to which it can achieve the interrelated readiness relevant activities using fuzzy cognitive maps. Based on the interrelationship degrees among the activities, the approach clusters the activities into manageable groups and prioritizes them. To help work out a readiness improvement plan, scenario analysis is conducted. 相似文献
3.
Artificial bee colony (ABC) algorithm has several characteristics that make it more attractive than other bio-inspired methods. Particularly, it is simple, it uses fewer control parameters and its convergence is independent of the initial conditions. In this paper, a novel artificial bee colony based maximum power point tracking algorithm (MPPT) is proposed. The developed algorithm, does not allow only overcoming the common drawback of the conventional MPPT methods, but it gives a simple and a robust MPPT scheme. A co-simulation methodology, combining Matlab/Simulink™ and Cadence/Pspice™, is used to verify the effectiveness of the proposed method and compare its performance, under dynamic weather conditions, with that of the Particle Swarm Optimization (PSO) based MPPT algorithm. Moreover, a laboratory setup has been realized and used to experimentally validate the proposed ABC-based MPPT algorithm. Simulation and experimental results have shown the satisfactory performance of the proposed approach. 相似文献
4.
This work considers the problem of increasing the performance of the ciphers based on Data-Dependent (DD) operations (DDO)
for VLSI implementations. New minimum size primitives are proposed to design DDOs. Using advanced DDOs instead of DD permutations
(DDP) in the DDP-based iterative ciphers Cobra-H64 and Cobra-H128 the number of rounds has been significantly reduced yielding
enhancement of the “performance per cost” value and retaining security at the level of indistinguishability from a random
transformation. To obtain further enhancement of this parameter a new crypto-scheme based on the advanced DDOs is proposed.
The FPGA implementation of the proposed crypto-scheme achieves higher throughput value and minimizes the allocated resources
than the conventional designs. Design of the DDO boxes of different orders is considered and their ASIC implementation is
estimated. 相似文献
5.
6.
流程企业资源计划及实施过程 总被引:1,自引:0,他引:1
流程企业面对电子商务的经济模式需要全面转变,实现真正意义上的畅通于客户、企业内部和供应商之间的供应链。本文介绍ERP的概念,流程企业的五个特点、信息化实施过程的七个步骤和通过实施ERP可获得的效益。 相似文献
7.
Steven Y. Susswein Thomas C. Henderson Joseph L. Zachary Chuck Hansen Paul Hinker Gary C. Marsden 《International journal of parallel programming》1991,20(6):453-473
Filtering algorithms are well accepted as a means of speeding up the solution of the consistent labeling problem (CLP). Despite the fact that path consistency does a better job of filtering than arc consistency, AC is still the preferred technique because it has a much lower time complexity. We are implementing parallel path consistency algorithms on multiprocessors and comparing their performance to the best sequential and parallel arc consistency algorithms.(1,2) (See also work by Kerethoet al.
(3) and Kasif(4)) Preliminary work has shown linear performance increases for parallelized path consistency and also shown that in many cases performance is significantly better than the theoretical worst case. These two results lead us to believe that parallel path consistency may be a superior filtering technique. Finally, we have implemented path consistency as an outer product computation and have obtained good results (e.g., linear speedup on a 64K-node Connection Machine 2). 相似文献
8.
在分析本钢物资计量信息网络系统升级扩展项目需求及技术方案的基础上,重点阐述了系统的设计和实现技术,详细介绍了基于DES算法的操作权限控制、系统数据库与本地数据库业务词典的异步维护等关键技术,解决了ERP下抛数据编码体系与系统数据库数据编码体系不一致的问题。系统设计采用J2EE架构B/S和C/S混合模式,以Oracle 9i为数据库服务器,Tomcat提供应用服务。 相似文献
9.
近年来,为了更好地应对新的市场挑战,钢铁企业都在积极推进信息化建设,以实现管理提升、效益提升的目标。本文结合安钢集团的实际情况,对信息化实施策略进行初步的探讨,希望能对企业信息化建设有所借鉴。 相似文献
10.
Michael V. Antony 《Minds and Machines》1991,1(3):321-341
Fodor and Pylyshyn (1988) have argued that the cognitive architecture is not Connectionist. Their argument takes the following form: (1) the cognitive architecture is Classical; (2) Classicalism and Connectionism are incompatible; (3) therefore the cognitive architecture is not Connectionist. In this essay I argue that Fodor and Pylyshyn's defenses of (1) and (2) are inadequate. Their argument for (1), based on their claim that Classicalism best explains the systematicity of cognitive capacities, is an invalid instance of inference to the best explanation. And their argument for (2) turns out to be question-begging. The upshot is that, while Fodor and Pylyshyn have presented Connectionists with the important empirical challenge of explaining systematicity, they have failed to provide sufficient reason for inferring that the cognitive architecture is Classical and not Connectionist. 相似文献