全文获取类型
收费全文 | 1331篇 |
免费 | 11篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 4篇 |
综合类 | 2篇 |
化学工业 | 84篇 |
金属工艺 | 5篇 |
机械仪表 | 13篇 |
建筑科学 | 27篇 |
矿业工程 | 1篇 |
能源动力 | 5篇 |
轻工业 | 59篇 |
水利工程 | 18篇 |
石油天然气 | 1篇 |
无线电 | 44篇 |
一般工业技术 | 83篇 |
冶金工业 | 908篇 |
原子能技术 | 2篇 |
自动化技术 | 87篇 |
出版年
2023年 | 3篇 |
2019年 | 6篇 |
2018年 | 7篇 |
2017年 | 9篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 19篇 |
2012年 | 12篇 |
2011年 | 21篇 |
2010年 | 19篇 |
2009年 | 19篇 |
2008年 | 23篇 |
2007年 | 31篇 |
2006年 | 30篇 |
2005年 | 15篇 |
2004年 | 9篇 |
2003年 | 10篇 |
2002年 | 8篇 |
2001年 | 19篇 |
2000年 | 14篇 |
1999年 | 21篇 |
1998年 | 244篇 |
1997年 | 136篇 |
1996年 | 109篇 |
1995年 | 47篇 |
1994年 | 57篇 |
1993年 | 66篇 |
1992年 | 28篇 |
1991年 | 29篇 |
1990年 | 25篇 |
1989年 | 15篇 |
1988年 | 17篇 |
1987年 | 14篇 |
1986年 | 27篇 |
1985年 | 15篇 |
1984年 | 9篇 |
1983年 | 10篇 |
1982年 | 13篇 |
1981年 | 11篇 |
1980年 | 14篇 |
1979年 | 5篇 |
1978年 | 8篇 |
1977年 | 34篇 |
1976年 | 61篇 |
1975年 | 9篇 |
1973年 | 5篇 |
1971年 | 5篇 |
1955年 | 2篇 |
1930年 | 2篇 |
1927年 | 2篇 |
排序方式: 共有1343条查询结果,搜索用时 31 毫秒
71.
John?McCarthyEmail author Peter?Wright Michael?Cooke 《Cognition, Technology & Work》2004,6(2):107-116
In this paper, we argue that modelling human action as the execution of predetermined goals and cognition as information processing does not account for peoples experience with emerging technologies, which is as much about values, trust and identity as about executing tasks. We offer a complementary approach to information processing within cognitive ergonomics, which builds on Bruners characterisation of cognition as meaningmaking, and which sees human action as simultaneously creating and executing goals and human cognition as dialogical meaning making. An analysis of field work carried out in two ambulance control centres is employed to exemplify aspects of the creativity and responsivity of work activity that are central to our approach. Finally, in this context, we briefly consider how technological artefacts could be conceptualised as centres of value in an approach to cognitive ergonomics that attempts to accommodate the intellectual, emotional and valuative aspects of work activity. 相似文献
72.
Michael Cooke Graham Nickless Andrew Povey David James Roberts 《The Science of the total environment》1979,13(1):17-26
Sediments taken from the upper part of the Severn Estuary have been extracted by cyclic steam distillation into hexane. Analysis of the extract revealed a variety of organic pollutants including alkanes and several poly-nuclear aromatic hydrocarbons (PNA's). A PCB residue was detected and quantified using the technique of carbon-skeleton gas chromatography employing a 3% palladium catalyst and 2% RbCl salt column. The level of PCB in the sediments was found to be of the order of 1 ppm. No significant levels of poly-chlorinated napthalene (PCN) or DDT and related species were found.Organic contamination of one sediment (Arlingham) was found to be associated with the coal particles present in the sample. Levels of contamination at Arlingham were thus shown to be a function of sample composition rather than of the geographical location of the site. 相似文献
73.
74.
75.
As fabrication technology pushes the dimensions of ferromagnetic structures into the nanoscale, understanding the magnetization processes of these structures is of fundamental interest, and key to future applications in hard disk drives, magnetic random access memory and other 'spintronic' devices. Measurements on elongated magnetic nanostructures highlighted the importance of nucleation and propagation of a magnetic boundary, or domain wall, between opposing magnetic domains in the magnetization reversal process. Domain-wall propagation in confined structures is of basic interest and critical to the performance of a recently demonstrated magnetic logic scheme for spintronics. A previous study of a 500-nm-wide NiFe structure obtained very low domain-wall mobility in a three-layer device. Here we report room-temperature measurements of the propagation velocity of a domain wall in a single-layer planar Ni80Fe20 ferromagnetic nanowire 200 nm wide. The wall velocities are extremely high and, importantly, the intrinsic wall mobility is close to that in continuous films, indicating that lateral confinement does not significantly affect the gyromagnetic spin damping parameter to the extreme extent previously suggested. Consequently the prospects for high-speed domain-wall motion in future nanoscale spintronic devices are excellent. 相似文献
76.
Brian R. Bennett J. Brad Boos Mario G. Ancona N. A. Papanicolaou Graham A. Cooke H. Kheyrandish 《Journal of Electronic Materials》2007,36(2):99-104
Heterostructures for InAs-channel high-electron-mobility transistors (HEMTs) were investigated. Reactive AlSb buffer and barrier
layers were replaced by more stable Al0.7Ga0.3Sb and In0.2Al0.8Sb alloys. The distance between the gate and the channel was reduced to 7–13 nm to allow good aspect ratios for very short
gate lengths. In addition, n+-InAs caps were successfully deposited on the In0.2Al0.8Sb upper barrier allowing for low sheet resistance with relatively low sheet carrier density in the channel. These advances
are expected to result in InAs-channel HEMTs with enhanced microwave performance and better reliability. 相似文献
77.
J. D. Caldwell B. S. Cooke M. K. Greer 《Journal of the American Oil Chemists' Society》2011,88(11):1669-1674
Analysis of used frying oil samples by high performance liquid chromatography–size exclusion chromatography (HPLC–SEC or HPSEC)
was compared to AOCS Official Method Cd 20-91 (silica gel column chromatography) for the purpose of developing a rapid analysis
of total polar compounds (TPC). In a direct comparison of the two analytical methods using four different sets of used frying
oils (21 total oil samples) ranging from fresh to discard quality (4.3 to 35.4% TPC by column chromatography), the weight
percent total polar compounds (%TPC) determined by HPLC–SEC averaged 0.71% higher than the values by silica gel column chromatography.
Reproducibility of the HPLC–SEC method of s
r = 0.30 and RSDr% = 1.22 compares to the variability of s
r = 0.29 and RSDr = 1.3 for samples of approximately the same %TPC, reported in AOCS Method Cd 20-91. Because the rapid method does not separate
pure (non-polar) triacylglycerol (TAG) and polar, oxidized TAG (OX-TAG), a high concentration of OX-TAG will quantitatively
affect the results. This places practical limits on the types of studies to which the method may be applied if a separate
analysis for the OX-TAG is not performed. Advantages of the HPLC–SEC method include the following. It uses about 75% less
solvent than standard column chromatography methods for determination of %TPC. This HPLC–SEC method is very similar to AOCS
Official Method Cd 22-91, and thus, also separates and quantifies polymerized triacylglycerols. The HPLC–SEC method determines
both TAG polymer concentration and %TPC of used frying oils in about 1 h. 相似文献
78.
Gomez Maria J.; Fassinger Ruth E.; Prosser Joann; Cooke Kathleen; Mejia Brenda; Luna Jeanette 《Canadian Metallurgical Quarterly》2001,48(3):286
This study used qualitative methodology to investigate the career development of 20 notable Latinas. The emergent theory proposed that Latina career development is influenced by sociopolitical, cultural, contextual, and personal variables. Results suggested that (a) career paths tended to be unplanned and nonlinear; (b) background variables, socioeconornic status, and educational experiences influenced the participants' sense of self and career motivation; (c) family, culture, and cultural identity werr influential; (d) relational support systems, particularly those that involved extended family, spouses, and mentors, were important; and (e) the participants' optimism, persistence, passion, and capacity for cognitive reframing helped them cope with challenges and remain true to their values, beliefs, and sense of self. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
79.
80.
Brian Shelmadine Matt Cooke Thomas Buford Geoffrey Hudson Liz Redd Brian Leutholtz Darryn S Willoughby 《Journal of the International Society of Sports Nutrition》2009,6(1):16