全文获取类型
收费全文 | 1434篇 |
免费 | 49篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 16篇 |
综合类 | 2篇 |
化学工业 | 375篇 |
金属工艺 | 21篇 |
机械仪表 | 35篇 |
建筑科学 | 64篇 |
矿业工程 | 2篇 |
能源动力 | 45篇 |
轻工业 | 140篇 |
水利工程 | 9篇 |
石油天然气 | 2篇 |
无线电 | 118篇 |
一般工业技术 | 209篇 |
冶金工业 | 127篇 |
原子能技术 | 11篇 |
自动化技术 | 312篇 |
出版年
2023年 | 16篇 |
2022年 | 50篇 |
2021年 | 61篇 |
2020年 | 24篇 |
2019年 | 27篇 |
2018年 | 33篇 |
2017年 | 33篇 |
2016年 | 60篇 |
2015年 | 32篇 |
2014年 | 42篇 |
2013年 | 98篇 |
2012年 | 85篇 |
2011年 | 96篇 |
2010年 | 68篇 |
2009年 | 75篇 |
2008年 | 64篇 |
2007年 | 72篇 |
2006年 | 64篇 |
2005年 | 50篇 |
2004年 | 52篇 |
2003年 | 40篇 |
2002年 | 36篇 |
2001年 | 20篇 |
2000年 | 18篇 |
1999年 | 19篇 |
1998年 | 38篇 |
1997年 | 33篇 |
1996年 | 20篇 |
1995年 | 24篇 |
1994年 | 26篇 |
1993年 | 16篇 |
1992年 | 13篇 |
1991年 | 9篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1988年 | 8篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 9篇 |
1982年 | 2篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1977年 | 3篇 |
1976年 | 6篇 |
1973年 | 2篇 |
1970年 | 2篇 |
1963年 | 1篇 |
1903年 | 1篇 |
排序方式: 共有1488条查询结果,搜索用时 15 毫秒
981.
Guido Tack Leif Kornstaedt Gert Smolka 《Electronic Notes in Theoretical Computer Science》2006,148(2):79
This paper presents generic pickling and minimization mechanisms that are provided as services similar to garbage collection. Pickling is used to externalize and internalize data. Minimization means to maximize the sharing in arbitrary data structures. The paper introduces the notion of an abstract store as a formal basis for the algorithms, and analyzes design decisions for the implementation aspects of pickling and minimization. The mechanisms presented here are fully implemented in the Alice programming system. 相似文献
982.
N Jeremy Hill Thomas Navin Lal Michael Schr?der Thilo Hinterberger Barbara Wilhelm Femke Nijboer Ursula Mochty Guido Widman Christian Elger Bernhard Sch?lkopf Andrea Kübler Niels Birbaumer 《IEEE transactions on neural systems and rehabilitation engineering》2006,14(2):183-186
We summarize results from a series of related studies that aim to develop a motor-imagery-based brain-computer interface using a single recording session of electroencephalogram (EEG) or electrocorticogram (ECoG) signals for each subject. We apply the same experimental and analytical methods to 11 nonparalysed subjects (eight EEG, three ECoG), and to five paralyzed subjects (four EEG, one ECoG) who had been unable to communicate for some time. While it was relatively easy to obtain classifiable signals quickly from most of the nonparalyzed subjects, it proved impossible to classify the signals obtained from the paralyzed patients by the same methods. This highlights the fact that though certain BCI paradigms may work well with healthy subjects, this does not necessarily indicate success with the target user group. We outline possible reasons for this failure to transfer. 相似文献
983.
Efficient unbalanced merge-sort 总被引:1,自引:0,他引:1
Sorting algorithms based on successive merging of ordered subsequences are widely used, due to their efficiency and to their intrinsically parallelizable structure. Among them, the merge-sort algorithm emerges indisputably as the most prominent method. In this paper we present a variant of merge-sort that proceeds through arbitrary merges between pairs of quasi-ordered subsequences, no matter which their size may be. We provide a detailed analysis, showing that a set of n elements can be sorted by performing at most n⌊logn⌋ key comparisons. Our method has the same optimal asymptotic time and space complexity as compared to previous known unbalanced merge-sort algorithms, but experimental results show that it behaves significantly better in practice. 相似文献
984.
Guido Boella Leendert van der Torre Harko Verhagen 《Autonomous Agents and Multi-Agent Systems》2008,17(1):1-10
This special issue contains four selected and revised papers from the second international workshop on normative multiagent
systems, for short NorMAS07 (Boella et al. (eds) Normative multiagent systems. Dagstuhl seminar proceedings 07122, 2007),
held at Schloss Dagstuhl, Germany, in March 2007. At the workshop a shift was identified in the research community from a
legal to an interactionist view on normative multiagent systems. In this editorial we discuss the shift, examples, and 10
new challenges in this more dynamic setting, which we use to introduce the papers of this special issue. 相似文献
985.
JC Byrd D Lawrence DC Arthur MJ Pettenati R Tantravahi M Qumsiyeh J Stamberg FR Davey CA Schiffer CD Bloomfield 《Canadian Metallurgical Quarterly》1998,4(5):1235-1241
To date, neither the clinical significance of isolated trisomy 8, the most frequent trisomy in acute myeloid leukemia (AML), nor the effect of age within a single cytogenetic group has been examined. We report a large cohort of adult trisomy 8 patients and examine whether increasing age within a homogeneous cytogenetic group alters clinical outcome. Characteristics and outcome of patients with isolated trisomy 8 enrolled in the prospective Cancer and Leukemia Group B (CALGB) cytogenetic study CALGB 8461 are described. Isolated trisomy 8 was identified in 42 (3.03%) of 1387 patients enrolled in five CALGB treatment protocols. These patients had a median age of 64 (range, 16-79) years, 50% female proportion, and a low frequency of hepatomegaly (10%) or splenomegaly (10%). Laboratory features included a median white blood count of 7.3 x 10(9)/L, nonspecific French-American-British distribution, with 36% of patients having Auer rods. Treatment outcome was unsatisfactory with a complete remission (CR) rate of 59%, median CR duration of 13.6 months, and median survival of 13.1 months. Older age adversely affected outcome; trisomy 8 patients > or =60 years had both an inferior CR rate (40% versus 88%; P = 0.004) and overall survival (median, 4.8 versus 17.5 months; P = 0.01), as compared with those <60 years of age. Of the patients <60 years of age, only four remain alive, and all received noncytarabine-based intensive chemotherapy, followed in three cases by autologous (n = 2) or allogeneic (n = 1) stem cell transplant in CR1. Adults with AML and isolated trisomy 8 have a poor outcome that is accentuated by increasing age and is rarely cured with cytarabine-based therapy. Alternative investigational treatments should be considered for individuals with this AML subset. 相似文献
986.
This note presents a tuning design method for output time delayed control systems that satisfies the two disk mixed sensitivity control design specification. The key features of this method are that it focuses on the two disk mixed sensitivity problem; it handles multiple time delays and allows the majority of the calculations to be carried out as in the time delay free case. A numerical example is given to show how the procedure works. 相似文献
987.
M Schiffer 《Canadian Metallurgical Quarterly》1991,43(10):5337-5343
988.
The absorption equilibria and kinetics of pairs of alkaline-alkaline, alkaline-organic and organic-organic ions on acrylic fibres deprived of their ionic content have been studied. The kinetic and absorption equilibrium behaviour of a given ion in the presence of a second ion was found to be modified in way that depended on the affinities and/or rate constants of both. 相似文献
989.
Cornelis Verduyn Guido J. Breedveld Henk Schreuder W. Alexander Scheffers Johannes P. Van Dijken 《Yeast (Chichester, England)》1988,4(2):117-126
Hansenula polymorpha CBS 4732 grown on a variety of substrates contained very high activities of enzymes catalyzing the NADH-linked reduction of dihydroxyacetone, acetoin, diacetyl, acetol, methylglyoxal and acetone. The enzymes catalyzing these reductions have been purified and their kinetic properties are described. Three different enzymes were found responsible for the above-mentioned activities, namely: (1) dihydroxyacetone reductase; (2) acetone reductase; and (3) alcohol dehydrogenase. So far, the physiological function of dihydroxyacetone reductase and acetone reductase is obscure. The kinetic properties of dihydroxyacetone reductase and the regulation of the synthesis of this enzyme suggest that it does not function as a glycerol dehydrogenase. 相似文献
990.
Peter C. Lockemann Guido Moerkotte Andrea Neufeld Klaus Radermacher Norbert Runge 《Data & Knowledge Engineering》1993,10(3):229-257
Modelling is an integral part of engineering processes. Consequently, database design for engineering applications should take into account the modelling concepts used by engineers. On the other hand, these applications exhibit a wide diversity of modelling concepts. Rather than consolidating these into one single semantic data model one should aim for correspondingly specialized semantic models. This paper takes a constructive approach to developing such specialized models by proposing an Extensible Semantic Model (ESM) as the basis for declaring specialized semantic data models. The paper introduces a computerized environment for database design based on an ESM, and discusses the consequences of the ESM for a number of design tools: the need for a formal definition of the notion of modelling concept in order to have reliable and precise foundation for the extensions, declarative techniques for quickly introducing graphical representations for new concepts and for using them during schema design, conceptual-level test data generation for a designer-oriented evaluation of designs, and optimization techniques to control the wide latitude in mapping a conceptual schema to a logical schema. First experiences seem to point to considerable productivity gains during database design. 相似文献