全文获取类型
收费全文 | 1663篇 |
免费 | 28篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 7篇 |
化学工业 | 87篇 |
金属工艺 | 4篇 |
机械仪表 | 2篇 |
建筑科学 | 29篇 |
能源动力 | 6篇 |
轻工业 | 30篇 |
水利工程 | 3篇 |
无线电 | 79篇 |
一般工业技术 | 81篇 |
冶金工业 | 1335篇 |
原子能技术 | 2篇 |
自动化技术 | 29篇 |
出版年
2023年 | 5篇 |
2021年 | 7篇 |
2020年 | 5篇 |
2019年 | 3篇 |
2018年 | 8篇 |
2017年 | 9篇 |
2016年 | 6篇 |
2015年 | 7篇 |
2014年 | 6篇 |
2013年 | 15篇 |
2012年 | 13篇 |
2011年 | 14篇 |
2010年 | 14篇 |
2009年 | 17篇 |
2008年 | 11篇 |
2007年 | 8篇 |
2006年 | 12篇 |
2005年 | 11篇 |
2004年 | 10篇 |
2003年 | 13篇 |
2002年 | 11篇 |
2001年 | 6篇 |
2000年 | 8篇 |
1999年 | 54篇 |
1998年 | 443篇 |
1997年 | 227篇 |
1996年 | 171篇 |
1995年 | 88篇 |
1994年 | 79篇 |
1993年 | 88篇 |
1992年 | 13篇 |
1991年 | 21篇 |
1990年 | 18篇 |
1989年 | 23篇 |
1988年 | 17篇 |
1987年 | 6篇 |
1986年 | 8篇 |
1985年 | 12篇 |
1984年 | 10篇 |
1983年 | 8篇 |
1982年 | 12篇 |
1981年 | 10篇 |
1980年 | 15篇 |
1978年 | 8篇 |
1977年 | 33篇 |
1976年 | 79篇 |
1975年 | 10篇 |
1974年 | 5篇 |
1972年 | 4篇 |
1943年 | 5篇 |
排序方式: 共有1694条查询结果,搜索用时 15 毫秒
61.
Kylie B. Manning Nicholas Wyatt Lindsey Hughes Adam Cook Nicholas H. Giron Estevan Martinez Christopher G. Campbell Mathias C. Celina 《大分子材料与工程》2019,304(3)
The use of self‐assembling, pre‐polymer materials in 3D printing is rare, due to difficulties of facilitating printing with low molecular weight species and preserving their reactivity and/or functions on the macroscale. Akin to 3D printing of small molecules, examples of extrusion‐based printing of pre‐polymer thermosets are uncommon, arising from their limited rheological tuneability and slow reactions kinetics. The direct ink write (DIW) 3D printing of a two‐part resin, Epon 828 and Jeffamine D230, using a self‐assembly approach is reported. Through the addition of self‐assembling, ureidopyrimidinone‐modified Jeffamine D230 and nanoclay filler, suitable viscoelastic properties are obtained, enabling 3D printing of the epoxy–amine pre‐polymer resin. A significant increase in viscosity is observed, with an infinite shear rate viscosity of approximately two orders of magnitude higher than control resins, in addition to, an increase in yield strength and thixotropic behavior. Printing of simple geometries is demonstrated with parts showing excellent interlayer adhesion, unachievable using control resins. 相似文献
62.
Tom P. Wyatt An‐Ting Chien Satish Kumar Donggang Yao 《Polymer Engineering and Science》2014,54(12):2839-2847
This article describes a new gel‐spinning process for making high‐strength poly(ethylene oxide) (PEO) fibers. The PEO gel‐spinning process was enabled through an oligomer/polymer blend in place of conventional organic solvents, and the gelation and solvent‐like properties were investigated. A 92/8 wt% poly(ethylene glycol)/PEO gel exhibited a melting temperature around 45°C and was highly stretchable at room temperature. Some salient features of a gel‐spun PEO fiber with a draw ratio of 60 are tensile strength at break = 0.66 ± 0.04 GPa, Young's modulus = 4.3 ± 0.1 GPa, and a toughness corresponding to 117 MJ/m3. These numbers are significantly higher than those previously reported. Wide‐angle x‐ray diffraction of the high‐strength fibers showed good molecular orientation along the fiber direction. The results also demonstrate the potential of further improvement of mechanical properties. POLYM. ENG. SCI., 54:2839–2847, 2014. © 2014 Society of Plastics Engineers 相似文献
63.
Daniel Spinks Emma J. Shanks Laura A. T. Cleghorn Stuart McElroy Deuan Jones Daniel James Alan H. Fairlamb Julie A. Frearson Paul G. Wyatt Ian H. Gilbert 《ChemMedChem》2009,4(12):2060-2069
There is an urgent need for new drugs for the treatment of tropical parasitic diseases such as human African trypanosomiasis, which is caused by Trypanosoma brucei. The enzyme trypanothione reductase (TryR) is a potential drug target within these organisms. Herein we report the screening of a 62 000 compound library against T. brucei TryR. Further work was undertaken to optimise potency and selectivity of two novel‐compound series arising from the enzymatic and whole parasite screens and mammalian cell counterscreens. Both of these series, containing either a quinoline or pyrimidinopyrazine scaffold, yielded low micromolar inhibitors of the enzyme and growth of the parasite. The challenges of inhibiting TryR with druglike molecules is discussed. 相似文献
64.
Bruce Moon Mike Berry Stephen Harris Ray Wyatt Kim Dovey Michelle Bennett 《Urban Policy and Research》2013,31(2):247-276
Australian Environmental Policy 2: Studies in Decline and Devolution Ken Walker and Kate Crowley (eds) UNSW Press, Sydney, 1999 ISBN 0868406732 (paperback) 323 pp.; bibliography and index RRP $35.00 Beyond Meltdown: The Global Battle for Sustained Growth. Peter Brain. Scribe, Melbourne, 1999 ISBN 0908011369 (paperback) 273 pp.; bibliography and index RRP $26.95 Cities Back from the Edge: New Life for Downtown Roberta Brandes Gratz with Norman Mintz John Wiley & Sons, New York, 1998 ISBN 0471144177 (hardback) 347 pp.; index RRP $59.95 Evaluation in Planning: Facing the Challenge of Complexity Nathaniel Lichfield, Angela Barbanente, Dino Bori, Abdul Khakee and Anna. Prat (eds). Kluwer, Dordrecht, 1998. ISBN 0792351770 (hardback). 383 pp.; index. RRP $254.00 Gritty Cities: Images of the Urban Lyaranette Finch and Chris McConville (eds). Pluto, Sydney, 1999. ISBN 1864030631 (paperback). 250 pp.; bibliography and index. RRP $24.95 Setting the Stage for Systainability: A Citizen's Handbook Chris Maser, Russ Beaton and Kevin Smith Lewis Publishers, Boca Raton, 1998 ISBN 1574441876 (hardback) 269 pp.; index RRP $47.50 The Australian Metropolis: A Planning History Stephen Hamnett and Robert Freestone (eds) Allen & Unwin, Sydney, 1999 ISBN 1865080535 (paperback) 229 pp.; index RRP $35.00 相似文献
65.
Ray Wyatt 《Urban Policy and Research》2013,31(1):8-12
Abstract How to guard against misinterpreting questionnaire data is explained, using a survey of residents' environmental attitudes as an illustration. Environmental attitudes in streets having high-traffic, low-traffic and “rejuvenated” environments are discussed, along with the limitations of questionnaire data. 相似文献
66.
67.
Hoeckner Berthold; Wyatt Emma W.; Decety Jean; Nusbaum Howard 《Canadian Metallurgical Quarterly》2011,5(2):146
Film music has powerful aesthetic effects on the perception and understanding of screen content, but does it also influence viewers' sense of connection with movie characters thereby creating antecedents for an experience of empathy? Participants viewed clips showing characters' neutral or ambiguous reaction to an event, person, or object. Viewers rated character likability and their certainty about characters' thoughts in three conditions: thriller music, melodrama music, and no music. The effect of music conditions differed significantly from the no music condition. Compared to melodramatic music, thriller music significantly lowered likability and certainty about characters' thoughts. During subsequent cued recall of screen content, thriller music increased anger attributions and lowered sadness attributions, while melodramatic music increased love attributions and lowered fear attributions. The study provides evidence that film music can influence character likability and the certainty of knowing the character's thoughts, which are antecedents of empathetic concern and emphatic accuracy. Thus film music may be regarded as modulating antecedents of empathic concern and empathic accuracy. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
68.
A. F. G. Wyatt I. N. Adamenko K. E. Nemchenko 《Journal of Low Temperature Physics》2002,126(1-2):609-614
We calculate the energy density of high energy phonons created from a pulse of low energy phonons spatially confined to a narrow cone. We include the tangential expansion of the propagating pulse and the interactions between high energy phonons within the pulse as well with low energy phonons. The expansion of the pulse causes it to cool so much that the creation of high energy phonons stops within 3 mm of the heater. The decay rate of high energy phonons governs the dynamic equilibrium inside the pulse. The magnitude of the high energy phonons, emitted by the pulse into the cold liquid helium, is calculated for different length pulses. It is found that small heaters can produce short pulses of high energy phonons from relatively long injected pulses. 相似文献
69.
70.