全文获取类型
收费全文 | 532篇 |
免费 | 20篇 |
专业分类
电工技术 | 6篇 |
化学工业 | 97篇 |
金属工艺 | 12篇 |
机械仪表 | 8篇 |
建筑科学 | 17篇 |
矿业工程 | 3篇 |
能源动力 | 11篇 |
轻工业 | 51篇 |
水利工程 | 2篇 |
无线电 | 44篇 |
一般工业技术 | 56篇 |
冶金工业 | 181篇 |
原子能技术 | 2篇 |
自动化技术 | 62篇 |
出版年
2022年 | 6篇 |
2021年 | 7篇 |
2018年 | 12篇 |
2017年 | 8篇 |
2016年 | 9篇 |
2015年 | 4篇 |
2014年 | 10篇 |
2013年 | 14篇 |
2012年 | 19篇 |
2011年 | 26篇 |
2010年 | 27篇 |
2009年 | 13篇 |
2008年 | 13篇 |
2007年 | 12篇 |
2006年 | 15篇 |
2005年 | 21篇 |
2004年 | 19篇 |
2003年 | 14篇 |
2002年 | 10篇 |
2001年 | 10篇 |
2000年 | 15篇 |
1999年 | 16篇 |
1998年 | 43篇 |
1997年 | 22篇 |
1996年 | 23篇 |
1995年 | 10篇 |
1994年 | 9篇 |
1993年 | 13篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 5篇 |
1988年 | 8篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 8篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 9篇 |
1976年 | 17篇 |
1975年 | 4篇 |
1974年 | 3篇 |
1973年 | 10篇 |
1972年 | 4篇 |
1971年 | 4篇 |
排序方式: 共有552条查询结果,搜索用时 15 毫秒
1.
N. Leclerc A. Michaud K. Sirois J.‐F. Morin M. Leclerc 《Advanced functional materials》2006,16(13):1694-1704
New electroactive and photoactive conjugated copolymers consisting of alternating 2,7‐carbazole and oligothiophene moieties linked by vinylene groups have been developed. Different oligothiophene units have been introduced to study the relationship between the polymer structure and the electronic properties. The resulting copolymers are characterized by UV‐vis spectroscopy, size‐exclusion chromatography, and thermal and electrochemical analyses. Bulk heterojunction photovoltaic cells from different copolymers and a soluble fullerene derivative, [6,6]‐phenyl‐C61 butyric acid methyl ester, have been fabricated, and promising preliminary results are obtained. For instance, non‐optimized devices using poly(N‐(4‐octyloxyphenyl)‐2,7‐carbazolenevinylene‐alt‐3″,4″‐dihexyl‐2,2′;5′,2″;5″,2″′;5″′,2″″‐quinquethiophenevinylene 1″,1″‐dioxide) as an absorbing and hole‐carrier semiconductor exhibit power conversion efficiency up to 0.8 % under air mass (AM) 1.5 illumination. These features make 2,7‐carbazolenevinylene‐based and related polymers attractive candidates for solar‐cell applications. 相似文献
2.
Kwok Kee Chan Rao S.K. Morin G.A. Tang M.Q. 《Antennas and Propagation, IEEE Transactions on》1997,45(8):1277-1285
A new method of analysis for the radiation characteristics of dielectric lens antennas with arbitrary inner and outer surfaces is presented. The analysis is based on representing the feed illumination by a contiguous set of ray tubes and including the effects of surface reflections and ray divergence. Radiation patterns and the antenna gain are then computed by evaluating the closed-form expressions developed for the Kirchhoff's integral of the aperture fields. The validity of the analysis method has been demonstrated by comparing the computations with measured results of two different spherical lenses and a shaped lens configurations. The analysis method presented takes into account some of the practical aspects associated with lens design such as surface zoning to reduce the mass and surface matching to minimize the reflection loss 相似文献
3.
MF Berthault J Morin M Dubar A Ktorza P Ferré L Pénicaud 《Canadian Metallurgical Quarterly》1996,89(8):1103-1106
This study was aimed to determine the effects of rilmenidine, an hypertensive drug, in an animal model of hypertension associated with insulin resistance, i.e. rats fed on a high fructose diet. Wistar rats were fed during four weeks either on a standard diet (S) or on a high fructose diet (F, 34.5% de fructose). In half of the F groups, rilmenidine (1 mg/kg/day) was added to the drinking water during the two last weeks of the diet (FR). Arterial blood pressure as well as insulin efficiency were determined at the end of the four weeks. Body weight gain was higher in F than in S rats (66 +/- 8 g versus 45 +/- 8 g; p < 0.05), this was prevented by rilmenidine treatment (32 +/- 2 g). Arterial systolic blood pressure was increased in F rats (162 +/- 2 vs 155 +/- 2 mmHg; p < 0.05), rilmenidine brought this value back to normal (149 +/- 3 mmHg). During the euglycemic hyperinsulinemic clamp, glucose utilization was lower (10 +/- 1 vs 14 +/- 1.5 mg/min/kg; p < 0.05) and hepatic glucose production higher (1 +/- 0.01 vs 0 mg/min/kg; p < 0.01) in F than in S rats. These changes in insulin action were totally abolished by rilmenidine. These data demonstrate that rilmenidine can ameliorate the deleterious effects of a high fructose diet, i.e. weight gain, hypertension and resistance to the effects of insulin Rilmenidine could represent a potential therapeutic agent for the treatment of hypertension associated with metabolic disorders such as syndrom X and obesity. 相似文献
4.
Evolution of the capillary network in a reactive powder concrete during hydration process 总被引:7,自引:0,他引:7
V. Morin F. Cohen-Tenoudji A. Feylessoufi P. Richard 《Cement and Concrete Research》2002,32(12):1907-1914
Ultrasonic waves in echographic mode, combined with autogenous shrinkage measurements, were used to study the evolution of the capillary network of reactive powder concrete (RPC) from the time after the mixing. Two characteristic porous classes have been identified: the first, between 10 and 20 nm, begins when the material reaches its solid hyperstatic state, and the second about 1 or 2 nm. The first class is associated with the porous space between the C-S-H hydrate clusters and the second with the internal porosity of the hydrate. The evolution of the active capillary radius as a function of the degree of hydration allows us to understand the strong interaction between the capillary network size and the chemical activity given by the dissipated calorimetric power curve. Indeed, the maximum point of the chemical activity marks the transition of the first class of pores to the second one. Finally, measurements of electrical conductivity through RPC samples show that after the maximum of the dissipated power, the curve of this electrical conductivity presents the same evolution as the capillary radius. As the electrical conductivity clearly depends on the evolution of the capillary network, the similarity between the results confirms our analysis in pore classes. 相似文献
5.
A novel miniature multilayer MMIC CPW single side band CPW mixer for up conversion at 44.5 GHz 总被引:1,自引:0,他引:1
Hettak K. Morin G.A. Stubbs M.G. 《Microwave and Wireless Components Letters, IEEE》2005,15(9):606-608
This letter presents the results of a novel miniature single sideband (SSB) subharmonic direct upconverter GaAs MMIC developed in multilayer coplanar waveguide. The mixer uses 50 MHz I and Q signals to directly modulate the second harmonic of a 22.25 GHz carrier, producing the required 44.55 GHz RF output. Two pairs of antiparallel diodes reduce feedthrough of the fundamental 22.25 GHz signal to the RF output while novel coplanar waveguide/asymmetric coplanar stripline, centre conductor based structures provide matching. This 1.7/spl times/1.7 mm/sup 2/ chip also uses a previously developed, reduced size Wilkinson divider based on asymmetric coplanar stripline and a reduced size three-dimensional 90/spl deg/ coupler. 相似文献
6.
The automatic compilation of bilingual lists of terms from specialized comparable corpora using lexical alignment has been successful for single-word terms (SWTs), but remains disappointing for multi-word terms (MWTs). The low frequency and the variability of the syntactic structures of MWTs in the source and the target languages are the main reported problems. This paper defines a general framework dedicated to the lexical alignment of MWTs from comparable corpora that includes a compositional translation process and the standard lexical context analysis. The compositional method which is based on the translation of lexical items being restrictive, we introduce an extended compositional method that bridges the gap between MWTs of different syntactic structures through morphological links. We experimented with the two compositional methods for the French–Japanese alignment task. The results show a significant improvement for the translation of MWTs and advocate further morphological analysis in lexical alignment. 相似文献
7.
LR Morin FP Fossey A Besselièvre JC Loisel JN Edwards 《Canadian Metallurgical Quarterly》1993,72(2):120-121
Congenital pseudarthrosis of the clavicle is a rare anomaly in which the clavicle is formed in utero in two separate segments. Clinically, there is a bump and a palpable discontinuity at the middle of the clavicle. There is no swelling or tenderness, nor disability. Radiologically, the medial ends of both clavicular segments are blunt and there is no interruption of cortical bone. The differential diagnosis includes birth fracture of the clavicle and craniocleidal dysostosis. The obstetrician should be aware of this condition as, if it is misdiagnosed, he may be wrongly accused of birth fracture. 相似文献
8.
Freeman SR Quick MK Morin MA Anderson RC Desilets CS Linnenbrink TE O'Donnell M 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》1999,46(2):320-332
The principles of oversampling are exploited in a simple beamforming architecture using a single bit delta-sigma (DeltaC) analog to digital converter (A/D) on every channel. The high sampling rate required for the single bit A/D provides adequate delay accuracy for high quality beamforming using elementary sample manipulations. Images produced with this beamformer exhibit significant artifacts directly related to dynamic focusing. However, a simple digital recording technique following delays permits dynamically focused beamforming without degrading image quality. The simplicity of this beamformer compared to conventional methods may facilitate very large channel count or low power beamformers suitable for 1.5-D arrays or portable scanners. 相似文献
9.
10.
David Morin Yoann Stevenin Cédric Grolleau Pascal Brault 《International Journal of Hydrogen Energy》2018,43(45):21017-21029
Nowadays islanded microgrids mostly rely on diesel generator. In order to reduce greenhouse emissions, two islanded microgrids with hydrogen storage have been installed and are currently working autonomously in Reunion Island and France. Energy management implemented on these stations fall in the myopic control category. This study aims to determine the performance improvement that could be achieve on such stations using model predictive control. Ability to supply to the loads and energy losses minimisation are our main objectives. Lifetime degradation is also taken in consideration. Simulations shows that significant improvement can be brought, with a 76% decrease of the station's defaults time and better fill rate of hydrogen tank and batteries. In the meantime, chemical and electrical losses are reduced by 38 and 11%, and the batteries degradations are decreased by around 1%. The relevance of taking into account the electrolyser and fuel cell degradations depends on the time-step of the control. These results give a performance target in order to implement a real-time model predictive control in the microgrids, and eventually can be used to better sizing of future microgrids with similar architecture. 相似文献