全文获取类型
收费全文 | 1010篇 |
免费 | 9篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 16篇 |
化学工业 | 275篇 |
金属工艺 | 9篇 |
机械仪表 | 18篇 |
建筑科学 | 20篇 |
矿业工程 | 2篇 |
能源动力 | 39篇 |
轻工业 | 167篇 |
水利工程 | 10篇 |
石油天然气 | 6篇 |
无线电 | 62篇 |
一般工业技术 | 146篇 |
冶金工业 | 80篇 |
原子能技术 | 6篇 |
自动化技术 | 164篇 |
出版年
2024年 | 7篇 |
2023年 | 8篇 |
2022年 | 32篇 |
2021年 | 54篇 |
2020年 | 26篇 |
2019年 | 40篇 |
2018年 | 24篇 |
2017年 | 32篇 |
2016年 | 28篇 |
2015年 | 35篇 |
2014年 | 42篇 |
2013年 | 75篇 |
2012年 | 53篇 |
2011年 | 70篇 |
2010年 | 44篇 |
2009年 | 52篇 |
2008年 | 51篇 |
2007年 | 39篇 |
2006年 | 31篇 |
2005年 | 29篇 |
2004年 | 29篇 |
2003年 | 19篇 |
2002年 | 16篇 |
2001年 | 23篇 |
2000年 | 16篇 |
1999年 | 9篇 |
1998年 | 28篇 |
1997年 | 15篇 |
1996年 | 17篇 |
1995年 | 12篇 |
1994年 | 8篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1973年 | 3篇 |
1960年 | 2篇 |
1956年 | 1篇 |
排序方式: 共有1020条查询结果,搜索用时 0 毫秒
61.
Caramazza Alfonso; Costa Albert; Miozzo Michele; Bi Yanchao 《Canadian Metallurgical Quarterly》2001,27(6):1430
In a series of experiments, the authors investigated whether naming latencies for homophones (e.g., /nΛn/) are a function of specific-word frequency (i.e., the frequency of nun) or a function of cumulative homophone frequency (i.e., the sum of the frequencies of nun and none). Specific-word but not cumulative-homophone frequency affected picture-naming latencies. This result was obtained in 2 languages (English and Chinese). An analogous finding was obtained in a translation task, where bilingual speakers produced the English names of visually presented Spanish words. Control experiments ruled out that these results are an artifact of orthographic or articulatory factors, or of visual recognition. The results argue against the hypothesis that homophones share a common word-form representation, and support instead a model in which homophones have fully independent representations. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
62.
L Bravo RJ Monté V Alfonso N Cabrera M Gómez R Hernández B García 《Canadian Metallurgical Quarterly》1995,47(3):215-216
One hundred and fifty-five strains of Aeromonas isolated in the stools of children under 5 years presenting with acute diarrheal disease were studied. Using the Aerokey II system for the identification of species, 47 strains were identified as Aeromonas caviae, 58 as Aeromonas hydrophila, 23 as Aeromonas veronii biovar sobria, 14 as Aeromonas trota, 9 as Aeromonas veronii biovar veronii, 2 as Aeromonas jandaei and 2 as Aeromonas shubertii, Emphasis is placed on the advantages of this method which allowed for the classification of new species not identified previously in our country. 相似文献
63.
Cutthroat Measurement Flume Calibration for Free and Submerged Flow Using a Single Equation 总被引:1,自引:0,他引:1
A series of detailed laboratory measurements were made under steady-state flow conditions through a 0.914-m (3-ft) Cutthroat flume in an attempt to more accurately define transition submergence for four standard throat widths. It was found that the change from free to submerged flow, and vice versa, is gradual and that there is no easily observable transition point. The gradual transition between the flow regimes suggested a new calibration approach in which a single equation could more elegantly and more accurately fit the laboratory measurements, eschewing the need for separate free- and submerged-flow equations, and obviating the need to define transition submergence. Such an equation was found, providing greater calibration accuracy up to 95% submergence in 0.914-m Cutthroat flumes. 相似文献
64.
Clara L. Hedegaard Estelle C. Collin Carlos Redondo‐Gómez Luong T. H. Nguyen Kee Woei Ng Alfonso A. Castrejón‐Pita J. Rafael Castrejón‐Pita Alvaro Mata 《Advanced functional materials》2018,28(16)
Effective integration of molecular self‐assembly and additive manufacturing would provide a technological leap in bioprinting. This article reports on a biofabrication system based on the hydrodynamically guided co‐assembly of peptide amphiphiles (PAs) with naturally occurring biomolecules and proteins to generate hierarchical constructs with tuneable molecular composition and structural control. The system takes advantage of droplet‐on‐demand inkjet printing to exploit interfacial fluid forces and guide molecular self‐assembly into aligned or disordered nanofibers, hydrogel structures of different geometries and sizes, surface topographies, and higher‐ordered constructs bound by molecular diffusion. PAs are designed to co‐assemble during printing in cell diluent conditions with a range of extracellular matrix (ECM) proteins and biomolecules including fibronectin, collagen, keratin, elastin‐like proteins, and hyaluronic acid. Using combinations of these molecules, NIH‐3T3 and adipose derived stem cells are bioprinted within complex structures while exhibiting high cell viability (>88%). By integrating self‐assembly with 3D‐bioprinting, the study introduces a novel biofabrication platform capable of encapsulating and spatially distributing multiple cell types within tuneable pericellular environments. In this way, the work demonstrates the potential of the approach to generate complex bioactive scaffolds for applications such as tissue engineering, in vitro models, and drug screening. 相似文献
65.
Alfonso Ranalli Gabriella De Mattia & Maria L. Ferrante 《International Journal of Food Science & Technology》1997,32(4):289-297
To evaluate the level of quality of the olive oil given by a new processing system we compared it with the percolation oil, which is known to be of high quality. The new product was characterized by the following: (i) higher contents of tocopherols, tyrosol- and hydroxytyrosol-aglycones, volatile aromatic substances, sterols, triterpene alcohols and lipochromes, and higher values of 1,2-diglycerides/1,3-diglycerides and campesterol/stigmasterol ratios, colour indices and turbidity; (ii) lower contents of waxes and triterpene dialcohols, and lower values for spectrophotometric indices, carbonyl index, Wolff's ratio (K232 /K270 ), acidity, and peroxide number; (iii) similar contents of phenols, o- diphenols, free tyrosol, free hydroxytyrosol, triglycerides, stigmastadienes, and aliphatic alcohols, similar sensory score, and similar value of resistance to autoxidation, alcohol index, overall quality indices, and fatty acid composition. 相似文献
66.
67.
何谓永恒城市与火车之间的爱恨情仇/关系源远流长,有过激情四溢的乐章,也有过痛苦折磨的片断,有过甜蜜美好的瞬间,也有公诸于众的背叛。而今,两者之间的关系历经变化,今非昔比。然而在巴伦西亚的杰昆·索罗拉火车站,城市与火车之间的激情烈焰仍在燃烧。新车站在允许高速火车进行停靠的同时,完成了将铁轨迁入地下的工程: 相似文献
68.
D.H. ChiversK. Alfonso B.L. Goldblum B. Ludewigt 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(16):1829-1835
An analytical model for the generation of β-delayed γ-ray spectra following thermal-neutron-induced fission of mixed samples of 235U and 239Pu is presented. Using an energy-dependent figure-of-merit to designate the spectral regions employed in the assay, the unique temporal β-delayed γ-ray signatures are utilized to determine the fraction of 239Pu in a mixed U-Pu sample. By evaluating the β-delayed γ-ray temporal signatures of both 235U and 239Pu within a 3 keV energy bin, traditional sources of systematic uncertainty in quantitative assay using β-delayed γ-ray signals, such as self-attenuation of the sample and energy-dependent γ-ray detection efficiency, are significantly reduced. The effects of the time-dependent Compton-continuum and growth of longer-lived nuclides on the quantitative assessment are explored. This methodology represents a promising extension of the conventional means of analysis for quantitative assay of fissile materials using β-delayed γ-ray signatures. 相似文献
69.
U. Pabel D. W?lfle M. Lahrssen-Wiederholt Alfonso Lampen 《Journal für Verbraucherschutz und Lebensmittelsicherheit》2008,1(1):252-258
Perfluorierte Tenside (PFT) werden seit einigen Jahren weltweit in der Umwelt, in menschlichen Blut- und Muttermilchproben sowie in Lebensmitteln nachgewiesen. In den letzten Jahren wurden auf nationaler und internationaler Ebene - zum überwiegenden Teil vorl?ufige - Risikobewertungen für die perfluorierten Tenside Perfluoroctans?ure (PFOA) und Perfluoroctansulfons?ure (PFOS) erarbeitet. Diese beiden Verbindungen werden als Leitsubstanzen für die Substanzklasse angesehen. Aus Sicht der humantoxikologischen Bewertung sind die lange Persistenz im menschlichen Organismus und die F?higkeit, im Tierversuch verschiedene adverse Effekte auszul?sen, als kritische Eigenschaften dieser Verbindungen anzusehen. Um den vielen Aspekten der Toxikologie von PFOS und PFOA gerecht zu werden, die im Rahmen dieser Darstellung nicht beleuchtet werden k?nnen, sei für weitere Informationen auf ausführliche übersichtsartikel verwiesen (Andersen et al., 2008; Lau et al., 2007). 相似文献
70.
Carlos Sáenz Begoña Hernández Coro Alberdi Santiago Alfonso José Manuel Diñeiro 《European Food Research and Technology》2008,227(5):1329-1338
We have designed a multispectral imaging acquisition system to measure the relative concentration values of myoglobin forms inside meat during oxygenation. Images at 474, 525, 572 and 610 nm are used to compute the concentration of reduced myoglobin, oxymyoglobin and metmyoglobin with a spatial resolution of 0.0125 mm/pixel. From these images, pigment concentration profiles as a function of oxygenation time and depth beneath the surface were obtained. A model describing the diffusion of oxygen and the consumption of reduced myoglobin is numerically tested versus the measured concentration profiles. The model accurately fits the data with a Mean Root Squared Error equal to 0.253%. Precise definitions for position and width of pigment layers based in concentration profiles are given. The results suggest that multispectral imaging techniques combined with precise control and measurement of sample temperature and oxygen partial pressure will permit detailed studies of the myoglobin chemistry during oxygenation. 相似文献