全文获取类型
收费全文 | 1166篇 |
免费 | 70篇 |
专业分类
电工技术 | 13篇 |
综合类 | 1篇 |
化学工业 | 399篇 |
金属工艺 | 8篇 |
机械仪表 | 24篇 |
建筑科学 | 70篇 |
能源动力 | 64篇 |
轻工业 | 203篇 |
水利工程 | 2篇 |
石油天然气 | 1篇 |
无线电 | 66篇 |
一般工业技术 | 164篇 |
冶金工业 | 17篇 |
原子能技术 | 6篇 |
自动化技术 | 198篇 |
出版年
2024年 | 1篇 |
2023年 | 19篇 |
2022年 | 72篇 |
2021年 | 77篇 |
2020年 | 39篇 |
2019年 | 34篇 |
2018年 | 45篇 |
2017年 | 32篇 |
2016年 | 52篇 |
2015年 | 50篇 |
2014年 | 49篇 |
2013年 | 87篇 |
2012年 | 70篇 |
2011年 | 83篇 |
2010年 | 79篇 |
2009年 | 73篇 |
2008年 | 54篇 |
2007年 | 55篇 |
2006年 | 38篇 |
2005年 | 37篇 |
2004年 | 34篇 |
2003年 | 28篇 |
2002年 | 17篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 11篇 |
1998年 | 11篇 |
1997年 | 4篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 8篇 |
1993年 | 4篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1985年 | 6篇 |
1984年 | 6篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 5篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有1236条查询结果,搜索用时 0 毫秒
111.
Andrea Petrella Valentina Petruzzelli Ezio Ranieri Vincenzo Catalucci 《Chemical Engineering Communications》2016,203(7):940-947
Selective sorption of lead, cadmium, and nickel ions on recycled waste porous glass beads was investigated. Single-metal equilibrations were carried out in demineralized water and ternary metal equilibrations were carried out in demi- and tap water. Freundlich isotherm gave a good correlation of the experimental data. Maximum metal retention (qmax) in single-ion solutions were 18.66 mg/gRPWG (0.090 mmol/gRPWG), 4.83 mg/gRPWG (0.043 mmol/gRPWG), 4.00 mg/gRPWG (0.068 mmol/gRPWG), respectively, for Pb+2, Cd+2, and Ni+2, and lower figures were in the case of ternary systems: 13.50 mg/gRPWG(0.065 mmol/gRPWG), 2.23 (0.020 mmol/gRPWG), 2.05 mg/gRPWG(0.034 mmol/gRPWG), respectively, for Pb+2, Cd+2, and Ni+2, with further drastic reduction in tap water. Metal exhausted beads were used as thermal insulators in cement mortars, minimizing their potential impact in the environment. 相似文献
112.
Biogenic amines are frequently found in wine and other fermented food. We investigated the ability of 133 strains of lactic acid bacteria isolated from musts and wines of different origins to produce histamine, tyramine, and putrescine. We detected the genes responsible for encoding the corresponding amino acid decarboxylases through PCR assays using two primer sets for every gene: histidine decarboxylase (hdc), tyrosine decarboxylase (tdc), and ornithine decarboxylase (odc); these primers were taken from the literature or designed by us. Only one strain of Lactobacillus hilgardii was shown to possess the hdc gene, whereas four strains of Lactobacillus brevis had the tdc gene. None of the Oenococcus oeni strains, the main agents of malolactic fermentation, was a biogenic amine producer. All PCR amplicon band-positive results were confirmed by thin-layer chromatography and high-performance liquid chromatography analyses. 相似文献
113.
114.
Vincenzo Levis 《Calcolo》1964,1(3-4):299-336
This Note takes again a late work byM. Volpato, which indicates the resolution. with method of dynamics programming, of a non-linear problem in Econometrics, for decide
theoptimum in a buying and selling business. When involved functions are linear, the question becomes aLP problem whose solutions is given from known methods.
Here, subject shows, by method of Volpato, a very easy proceeding involving only comparisons among the dates of question.
Moreover, the result confirms an intuitive rule of Economical Policy which, perhaps for the first time, is strictly justified.
Lavoro eseguito nell'ambito dell'attività del Gruppo di Ricerca n0 38 (Univ. ca' Foscari-Venezia) del Comitato per la matematica del C.N.R. per l'A.A. 1963–64. 相似文献
Lavoro eseguito nell'ambito dell'attività del Gruppo di Ricerca n0 38 (Univ. ca' Foscari-Venezia) del Comitato per la matematica del C.N.R. per l'A.A. 1963–64. 相似文献
115.
The first results of a new method for real-time shape acquisition with a laser scanner are presented. The new method is essentially based on the use of a laser beam and a web-cam. A digital filter parameters identification was studied for the laser line detection in the image. After this, a model for the reconstruction in real-time of the laser line in the space was developed. The first test rig was just conceived to validate the method; hence, no high resolution cameras were adopted. Nevertheless, the tests have showed encouraging results. 相似文献
116.
Giulio Giovannetti Francesca Frijia Simona Attanasio Luca Menichetti Valentina Hartwig Nicola Vanello Jan Henrik Ardenkjaer-Larsen Daniele De Marchi Vincenzo Positano Rolf Schulte Luigi Landini Massimo Lombardi Maria Filomena Santarelli 《Measurement》2013
Hyperpolarized 13C magnetic resonance spectroscopy in pig models enables cardiac metabolism assessment and provides a powerful tool for heart physiology studies, although the low molar concentration of derivate metabolites gives rise to technological limitations in terms of data quality. The design of dedicated coils capable of providing large field of view with high Signal-to-Noise Ratio (SNR) data is of fundamental importance. 相似文献
117.
Dane Bicanic Vincenzo Fogliano Svjetlana Luterotti Jan Swarts Giovanni Piani Giulia Graziani 《Journal of the science of food and agriculture》2005,85(7):1149-1153
A new photothermal method suitable for direct, accurate and highly reproducible quantitative measurements of lycopene in tomato products has been introduced. The intrinsic precision of the method is typically better than 0.2%; the repeatability of determination is comparable to that of high‐performance liquid chromatography, with 0.86% least overall error. Copyright © 2005 Society of Chemical Industry 相似文献
118.
Table olive quality depends on a number of factors, including fruit characteristics, ripening and processing technologies. Volatile and semi-volatile organic compounds, present both in the sample matrix and in the headspace aroma, are responsible for the olive fruit flavour influencing the consumer’s preference. 相似文献
119.
Several DSP algorithms need to remove high-frequency or impulsive noise while preserving edges, e.g., in speech and image processing applications: median filtering has been proved to be more effective for achieving this goal than other filtering techniques. Efficient architectural implementation for real-time applications involves a careful VLSI design, which takes into account modularity, regularity, adaptability, scalability, throughput, circuit complexity and fault tolerance. Four new architectural approaches are presented and evaluated in this paper to deal with different application and implementation constraints. They are: the serial-input polarizing median filter, the floating median filter, the pipelined polarizing median filter and the pipelined sorting median filter. The 1st and the 2nd architectures are based on majority voting, while the 3rd and the 4th ones are based on sorting techniques. All of them are designed so as to exhibit high scalability and to be easily pipelined for higher working frequencies. 相似文献
120.
我首先想要对读者表明我对建筑学的观点。我试图强调如何将理念融入到空间的创造中。这不仅仅是一个建筑学问题,而且是全人类表达的一个组成部分。对于那些问“一个好建筑师需要研究些什么?”的人,有人回答是技术、有人回答是造型、还有人回答是形体学问题等等。我个人的感觉是:人,这个观点也被其他很多思索者所认同。我们再一次地发现,如果我们探寻什么,真理要比它看起来遥远得多,有时甚至看不到,而且从不确定和讨人喜欢。 相似文献