全文获取类型
收费全文 | 589篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 36篇 |
金属工艺 | 16篇 |
机械仪表 | 7篇 |
建筑科学 | 14篇 |
矿业工程 | 2篇 |
能源动力 | 9篇 |
轻工业 | 18篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 40篇 |
一般工业技术 | 29篇 |
冶金工业 | 386篇 |
原子能技术 | 1篇 |
自动化技术 | 27篇 |
出版年
2022年 | 1篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 10篇 |
2012年 | 7篇 |
2011年 | 6篇 |
2010年 | 9篇 |
2009年 | 6篇 |
2008年 | 6篇 |
2007年 | 8篇 |
2006年 | 4篇 |
2005年 | 8篇 |
2004年 | 5篇 |
2003年 | 1篇 |
2002年 | 7篇 |
2001年 | 6篇 |
2000年 | 13篇 |
1999年 | 24篇 |
1998年 | 118篇 |
1997年 | 60篇 |
1996年 | 48篇 |
1995年 | 35篇 |
1994年 | 21篇 |
1993年 | 33篇 |
1992年 | 6篇 |
1991年 | 8篇 |
1990年 | 9篇 |
1989年 | 7篇 |
1988年 | 9篇 |
1987年 | 11篇 |
1986年 | 2篇 |
1985年 | 9篇 |
1984年 | 6篇 |
1983年 | 6篇 |
1982年 | 4篇 |
1981年 | 9篇 |
1980年 | 6篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 6篇 |
1976年 | 29篇 |
1975年 | 1篇 |
1974年 | 4篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1968年 | 1篇 |
排序方式: 共有591条查询结果,搜索用时 31 毫秒
1.
NW Tomkins NN Jonsson MP Young AN Gordon KA McColl 《Canadian Metallurgical Quarterly》1997,75(10):722-723
On the basis of clinical signs and histological findings eight 9-month-old male rusa deer (Cervus timorensis) were diagnosed with sheep associated-malignant catarrhal fever. Following a variable course involving rectal temperatures around 40.5 degrees C, depression, inappetence, diarrhoea, corneal opacity and hypopyon all animals died or were euthanased over a 5-week period. Severe multifocal vasculitis, mainly periglomerular and in the arcuate vessels were consistent histological findings which in the past have been adequate to confirm clinical diagnosis of sheep associated-malignant catarrhal fever. A nested polymerase chain reaction test has been used to detect a sheep associated-malignant catarrhal fever PRC product, 238 base-pairs in size, in DNA extracted from lymphocyte preparations. The result supported the diagnosis of sheep associated-malignant catarrhal fever in these deer. 相似文献
2.
3.
Mahmoud Mollabashi R. M. Lees Li-Hong Xu M. Bakota 《Journal of Infrared, Millimeter and Terahertz Waves》1993,14(12):2569-2582
The microwave spectrum of CD3OH has been studied over the 8 to 58 GHz region, and numerousb-type transitions have been assigned. Many of these belong toP subbranches which descend to the microwave region from subband origins lying much higher in the far-infrared, pass through zero frequency, and return upward again. Others are members ofb-typeQ branches which extend across the region. As well, variousa-typeK-doublet lines arising as transitions directly across the split levels of asymmetry doublets have been identified. 相似文献
4.
Since the advent of computed tomography (CT) traumatic intraventricular haemorrhage (IVH) has been diagnosed more often. It has reportedly been associated with a poor prognosis, but pure or solitary IVH is rare, suggesting that other lesions occurring concurrently with it may contribute to the poor outcome. In a series of 65 patients with severe head injury (GCS < or = 8), 14 (22%) had IVH on initial CT. Death rate in these 14 was 21%, not significantly different from that in patients without IVH (14%), although a significantly higher proportion of patients without IVH had a good outcome. These results suggest that mortality is related to other lesions associated with IVH rather than to IVH alone and that the presence of IVH does not necessarily lead to a poor outcome. 相似文献
5.
Roger Norman Rothon Christopher Mark Liauw Graham Clayton Lees Wayne Christopher Edward Schofield 《The Journal of Adhesion》2002,78(7):603-628
The interaction of ammonium stearate (AS) and γ-aminopropyltriethoxysilane (APS) treatments with a magnesium hydroxide flame retardant filler and their effects on its use in an ethylene vinyl acetate copolymer compound have been investigated. The work has shown clear evidence of changes in the structure of the surface layers formed on the filler as the amount of additive is increased and the levels at which these occur can be correlated with theoretical monolayer quantities. Infrared (IR) spectroscopy data suggest that the stearate coating changes from a half salt to a full salt as the coating level is increased and that the APS coating on the filler initially has a significant bicarbonate content, presumably due to reaction with atmospheric carbon dioxide. The effect of coating level on the melt flow rate, insoluble matrix content, crystallisation behaviour, tensile properties, limiting oxygen index, and ageing of the filled compound has been studied. Distinct trends have been observed, many of which can be correlated with the structure of the filler surface layers. Of particular importance is the observation that, unlike APS, excess stearate appears to promote detrimental ageing effects. 相似文献
6.
KE McLaughlin IN Jacobs NW Todd GS Gussack G Carlson 《Canadian Metallurgical Quarterly》1997,107(10):1322-1331
Nasopharyngeal stenosis and oropharyngeal stenosis are rare and challenging problems in the pediatric population. The most common etiology is currently the surgical trauma associated with adenotonsillectomy. Stenosis can vary from a thin band to a complete obstructing cicatrix. Presenting symptoms range from mild hyponasal speech to severe airway obstruction. We present a series of eight children with varying degrees of stenosis and associated symptoms. Choice of treatment varied with the severity of disease. In our series, successful interventions included triamcinolone acetonide injection, lysis of adhesions, rotational and advancement mucosal flaps, and jejunal free flap. Preoperative evaluation and individualized surgical repair are essential for successful treatment. 相似文献
7.
8.
A modification of the well-known water-quality model 'quality simulation along river systems'(QUASAR) is presented in order to extend its ability, so that it may be considered applicable under unsteady-flow conditions. An aggregated dead-zone travel-time parameter, based on (a) the kinematic wave velocity (celerity) of the flow wave and (b) the behaviour of the solute within so-called 'dead zones', has been incorporated into the existing model formulation. This extends the current continuously-stirred tank reactor-based model process to account for the behaviour of solute under unsteady-flow conditions. The enhanced water-quality model has been validated by application to the Colorado River. 相似文献
9.
TG Mackay D Georgiadis DG Grosset AW Kelman KR Lees DJ Wheatley 《Canadian Metallurgical Quarterly》1995,4(4):414-419
The application of transcranial Doppler (TCD) ultrasonography to asymptomatic prosthetic heart valve patients can result in detection of localized bursts of high intensity signals, similar to those caused by the passage of emboli. The origin of these signals is not known. In order to investigate this phenomenon in a simplified, more controllable environment, a TCD machine was used to record flow downstream from mechanical prosthetic heart valves in a mock circulatory loop. The model, which uses a saline solution seeded with silk particles (< 15 micrometers) as the circulatory fluid, recreates the principal hydrodynamic characteristics of the left heart and systemic circulation. Reproducibility of the system was established through repeated testing of a Monostrut valve. Three different mechanical valve types, (Monostrut, Medtronic Hall, St. Jude Medical) were tested over a range of simulated cardiac outputs, and the effect of valve size was investigated with four Omniscience tilting disc valves (21, 23, 25 and 29 mm). Average energy of the reflected Doppler signal was used to quantify the amount of high intensity Doppler signal, QTCD. TCD signals recorded in vitro were visually and aurally similar to those found in prosthetic heart valve patients. All valve types generated exponentially more QTCD with increasing simulated cardiac output. Differences amongst valve types were only significant at higher flow outputs, with the Monostrut valve producing the greatest QTCD. Larger valves consistently generated greater QTCD than smaller valves. In conclusion, TCD signals found in prosthetic heart valve patients can be reproduced, at least qualitatively, using a mock circulatory loop which does not incorporate the formed elements of blood.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
10.