全文获取类型
收费全文 | 945篇 |
免费 | 39篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 20篇 |
化学工业 | 221篇 |
金属工艺 | 7篇 |
机械仪表 | 11篇 |
建筑科学 | 63篇 |
矿业工程 | 6篇 |
能源动力 | 31篇 |
轻工业 | 115篇 |
水利工程 | 10篇 |
石油天然气 | 1篇 |
无线电 | 51篇 |
一般工业技术 | 206篇 |
冶金工业 | 93篇 |
原子能技术 | 8篇 |
自动化技术 | 146篇 |
出版年
2024年 | 2篇 |
2023年 | 8篇 |
2022年 | 13篇 |
2021年 | 28篇 |
2020年 | 19篇 |
2019年 | 15篇 |
2018年 | 30篇 |
2017年 | 29篇 |
2016年 | 31篇 |
2015年 | 25篇 |
2014年 | 33篇 |
2013年 | 69篇 |
2012年 | 50篇 |
2011年 | 46篇 |
2010年 | 47篇 |
2009年 | 39篇 |
2008年 | 42篇 |
2007年 | 45篇 |
2006年 | 45篇 |
2005年 | 27篇 |
2004年 | 32篇 |
2003年 | 26篇 |
2002年 | 23篇 |
2001年 | 12篇 |
2000年 | 18篇 |
1999年 | 15篇 |
1998年 | 30篇 |
1997年 | 22篇 |
1996年 | 13篇 |
1995年 | 11篇 |
1994年 | 18篇 |
1993年 | 14篇 |
1992年 | 14篇 |
1991年 | 10篇 |
1990年 | 4篇 |
1989年 | 11篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 9篇 |
1979年 | 8篇 |
1977年 | 3篇 |
1976年 | 12篇 |
1974年 | 3篇 |
1971年 | 2篇 |
排序方式: 共有989条查询结果,搜索用时 31 毫秒
1.
Machine Learning - We propose a data-driven approach to quantify the uncertainty of models constructed by kernel methods. Our approach minimizes the needed distributional assumptions, hence,... 相似文献
2.
3.
András Ványolos Balázs Dóra Attila Virosztek 《Journal of Superconductivity and Novel Magnetism》2007,20(7-8):643-645
We report of a theoretical study on quasi-one dimensional unconventional charge density wave (UCDW) driven by electron–phonon
interaction. Within mean field theory, we find that the wavevector dependence of the coupling leads to a momentum dependent
single particle gap on the Fermi surface. The presence of small energy single particle excitations around the gap nodes significantly
changes the optical conductivity compared to the conventional CDW result. In addition to that, the collective phase excitation
arising from fluctuation of the order parameter leads to further qualitative changes of the conductivity and results in an
effective mass that is nonmonotonic in temperature.
相似文献
4.
5.
L. B. Pavlovich N. N. Nazarov V. P. Dolgopolov A. V. Kalinina T. A. Bulis D. V. Bal’tser V. P. Konstantinov 《Coke and Chemistry》2008,51(7):277-282
The use of biochemically purified water in place of industrial-grade water for the exhaust-gas scrubbers in the drying department of the coal-enrichment shop and for irrigation of the cyclone washers in the coke shops at OAO ZSMK is considered. It is found that biochemically purified water may be used for 100% of the water needs in coke production. Using biochemically purified water in the dust-trapping equipment, the coaland coke-dust content of the atmospheric emissions may be reduced by 24.5%. Additional purification of wastewater by adsorption on coke and coal dust is possible. 相似文献
6.
Stabilization and termination of severe accidents in LWRs 总被引:1,自引:0,他引:1
The last 20 years of research on severe accident safety for light water reactors (LWRs) has resolved a number of issues. However, the issue of melt/debris coolability is still unresolved. At stake is the stabilization and termination of a severe accident, if ever it would occur. The stabilization and termination can be established only through the coolability of the melt or the particulate debris, which are found in-vessel, or ex-vessel, depending upon the extent of the progression of a postulated accident.This paper will review the state of the art of coolability during a severe accident for the current light water reactors (LWRs). It will also review whether the accident management actions will be effective in terminating a postulated severe accident. The attention paid to the stabilization and coolability in future LWRs will be discussed and the design solutions will be evaluated. 相似文献
7.
Tree-based partitioning of date for association rule mining 总被引:1,自引:1,他引:0
The most computationally demanding aspect of Association Rule Mining is the identification and counting of support of the frequent sets of items that occur together sufficiently often to be the basis of potentially interesting rules. The task increases in difficulty with the scale of the data and also with its density. The greatest challenge is posed by data that is too large to be contained in primary memory, especially when high data density and/or low support thresholds give rise to very large numbers of candidates that must be counted. In this paper, we consider strategies for partitioning the data to deal effectively with such cases. We describe a partitioning approach which organises the data into tree structures that can be processed independently. We present experimental results that show the method scales well for increasing dimensions of data and performs significantly better than alternatives, especially when dealing with dense data and low support thresholds.
Shakil Ahmed received a first class BSc (Hons) degree from Dhaka University, Bangladesh, in 1990; and an MSc (first class), also Dhaka University, in 1992. He received his PhD from The University of Liverpool, UK, in 2005. From 2000 onwards he is a member of the Data Mining Group at the Department of Computer Science of the University of Liverpool, UK. His research interests include data mining, Association Rule Mining and pattern recognition.
Frans Coenen has been working in the field of Data Mining for many years and has written widely on the subject. He received his PhD from Liverpool Polytechnic in 1989, after which he took up a post as a RA within the Department of Computer Science at the University of Liverpool. In 1997, he took up a lecturing post within the same department. His current Data Mining research interests include Association rule Mining, Classification algorithms and text mining. He is on the programme committee for ICDM'05 and was the chair for the UK KDD symposium (UKKDD'05).
Paul Leng is professor of e-Learning at the University of Liverpool and director of the e-Learning Unit, which is responsible for overseeing the University's online degree programmes, leading to degrees of MSc in IT and MBA. Along with e-Learning, his main research interests are in Data Mining, especially in methods of discovering Association Rules. In collaboration with Frans Coenen, he has developed efficient new algorithms for finding frequent sets and is exploring applications in text mining and classification. 相似文献
8.
L Haluska G Barancíková S Baláz K Dercová B Vrana M Paz-Weisshaar E Furciová P Bielek 《Canadian Metallurgical Quarterly》1995,175(3):275-285
The degradation of PCB in soils by the biphenyl-utilising strain Alcaligenes xylosoxidans was studied in different soil types. In addition to the congener specificity, significant differences in the degradation of PCB by the strain in the different soil types were observed. Efficiency of degradation was generally better in sterilised soils, but the differences were not as significant as the differences observed between different soil types. These results indicate that the degradation of PCB is probably related not only to the capabilities of the strain employed and quality and amount of competitive species inhabiting the soils, but also to the soil sorption of the PCB congeners. Degradation is faster in the soils containing an intermediate amount of organic carbon with a high portion of total and aromatic carbon in humic acids. 相似文献
9.
Tomasz Z. Tomkiewicz Nuria Surez-Herrera Frans P. M. Cremers Rob W. J. Collin Alejandro Garanto 《International journal of molecular sciences》2021,22(9)
The discovery of novel intronic variants in the ABCA4 locus has contributed significantly to solving the missing heritability in Stargardt disease (STGD1). The increasing number of variants affecting pre-mRNA splicing makes ABCA4 a suitable candidate for antisense oligonucleotide (AON)-based splicing modulation therapies. In this study, AON-based splicing modulation was assessed for 15 recently described intronic variants (three near-exon and 12 deep-intronic variants). In total, 26 AONs were designed and tested in vitro using a midigene-based splice system. Overall, partial or complete splicing correction was observed for two variants causing exon elongation and all variants causing pseudoexon inclusion. Together, our results confirm the high potential of AONs for the development of future RNA therapies to correct splicing defects causing STGD1. 相似文献
10.
Consequences of different cutting regimes on regrowth and nutrient stoichiometry of Sparganium erectum L. and Potamogeton natans L.
下载免费PDF全文
![点击此处可从《河流研究与利用》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Aquatic vegetation forms an essential component in freshwater ecosystems but due to changed environmental and anthropogenic conditions often needs management to reduce nuisance for human land‐use. In this paper, the authors looked at the regrowth of two macrophyte species (Potamogeton natans and Sparganium erectum) in two lowland rivers under different cutting treatments. After an initial cross‐sectional transect was manually removed from bank to bank at the beginning of the growth season, a monthly repetitive removal of biomass in plots on that transect was done during the rest of the growth season (testing frequency of mowing). Additional new transects were also cut in subsequent months (testing timing of mowing). Finally, biomass was repetitively removed in plots in those additional transects too (testing frequency of mowing × timing of mowing). The biomass at the end of the growth season was analysed for C, N, P, and Si. It was demonstrated that timing and frequency of vegetation cutting has an important effect on the capacity and rate of species' recovery and therefore on the efficiency of the applied management. Nutrient stoichiometry of the regrown biomass was directly affected by cutting. Caused by differences in the applied timing and frequency of the cutting, C/N and N/P ratios and BSi concentrations were highly variable. Yet, overall, there was a clear tendency towards a higher C/N ratio and BSi concentration and lower N/P ratio in biomass that recovered after cutting. This human impact on the quantity and quality of autochthonous organic matter may have knock‐on effects on the decomposers food web and mineralization process. 相似文献