全文获取类型
收费全文 | 157篇 |
免费 | 2篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 20篇 |
金属工艺 | 4篇 |
机械仪表 | 2篇 |
建筑科学 | 10篇 |
能源动力 | 1篇 |
轻工业 | 12篇 |
无线电 | 53篇 |
一般工业技术 | 25篇 |
冶金工业 | 11篇 |
自动化技术 | 17篇 |
出版年
2022年 | 1篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 4篇 |
2012年 | 7篇 |
2011年 | 4篇 |
2010年 | 7篇 |
2009年 | 4篇 |
2008年 | 4篇 |
2007年 | 7篇 |
2006年 | 4篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 10篇 |
2001年 | 4篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 9篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 9篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 6篇 |
1988年 | 1篇 |
1985年 | 3篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 1篇 |
1977年 | 3篇 |
1974年 | 1篇 |
1972年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1966年 | 2篇 |
排序方式: 共有159条查询结果,搜索用时 15 毫秒
1.
Button Cathryn M.; Grant Malcolm J.; Hannah T. Edward; Ross Abraham S. 《Canadian Metallurgical Quarterly》1993,25(2):230
Two studies identified and labeled the dimensions that people use to judge others' attitudes. In the 1st study, 50 male and 50 female undergraduates viewed pairs of attitude statements drawn from 1 or 2 large sets. For each pair of statements, Ss judged whether or not a person who agreed with one statement in the pair would be likely to agree with the other. The dimensions of liberalism and traditional values were found to underlie perceived attitudes. Validity was confirmed in a 2nd study with 60 male and 60 female undergraduates who rated the characteristics of hypothetical people who agreed strongly with particular statements. Results suggest that there is a common structure to people's perceptions of others' attitudes. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
2.
Lullo G. McKee A. McLean C.J. Bryce A.C. Button C. Marsh J.H. 《Electronics letters》1994,30(19):1623-1625
Electroabsorption optical modulators have been fabricated on GaInAs/GaInAsP multiquantum well structures whose bandgap had been increased by laser photoabsorption-induced disordering. Modulation depths of 20 dB have been obtained in material which has been bandgap blue shifted by as much as 120 nm, while samples shifted by 80 nm gave depths as high as 27 dB 相似文献
3.
A technique based on viscous polymer processing (VPP) was described, which can produce high ceramic content green fibers. PZT-5 ceramic powders were ball milled to get high dispersibility. The slurry prepared for VPP was a composition of PZT-5 powder, PVA binder and glycerin. High ceramic content PZT-5 fibers were extruded with the slurry. The results show that the ceramic powders have fine mean particle size of 0.54 pan, high specific surface area of 3.55 m^2/g and zeta potential of 8.81 mV after 16 h milling. The fibers sintered at 1 280 ℃ for 4 h have pure perovskite structure and grains of 2-5 μm in size, with little pores or cracks. The ultimate tensile strength of sintered fibers is up to 13.84 MPa compared with 2.88 MPa of green fibers. The remnant polarization (Pr) and coercive field (Ec) of the fibers are 50.65 μC/cm^2 and 2.45 kV/mm, respectively. This fiber can withstand an electric field of 9 kV/mm higher than the ceramic (5 kV/mm), which shows high directional and compact qualities. 相似文献
4.
Emily B. Button Andrew S. Mitchell Marcia M. Domingos Jessica H.-J. Chung Ryan M. Bradley Ashkan Hashemi Phillip M. Marvyn Ashley C. Patterson Ken D. Stark Joe Quadrilatero Robin E. Duncan 《Lipids》2014,49(4):305-316
Neuroinflammation is a component of age-related neurodegenerative diseases and cognitive decline. Saturated (SFA) and monounsaturated (MUFA) fatty acids are bioactive molecules that may play different extrinsic and intrinsic roles in neuroinflammation, serving as exogenous ligands for cellular receptors, or endogenous components of cell structural, energetic and signaling pathways. We determined the fatty acyl profile of BV2 microglial cells before and after acute activation with lipopolysaccharide (LPS). We also investigated the effect of SFA and MUFA pretreatment on the production of an invasive, neurotoxic phenotype in BV2 cells. Acute activation of BV2 microglia resulted in an increase in the relative content of SFA (12:0, 16:0, 18:0, 20:0, 22:0, and 24:0 increased significantly), and a relative decrease in the content of MUFA (16:1n7, 18:1n7, 18:1n9, 20:1n9, 24:1n9 decreased significantly). In agreement, the major stearoyl-CoA desaturase (SCD) isoform in BV2 cells, SCD2, was significantly down-regulated by LPS. We next treated cells with SFA (16:0 or 18:0) or MUFA (16:1n7 or 18:1n9), and found that levels of secreted IL6 were increased, as was secreted MMP9-mediated proteolytic activity. To test the functional significance, we treated SH-SY5Y neuronal cells with conditioned medium from BV2 cells pretreated with fatty acids, and found a small but significant induction of cell death. Our findings suggest differential intrinsic roles for SFA and MUFA in activated microglial cells, but similar extrinsic roles for these fatty acid species in inducing activation. Expansion of SFA is important during microglial cell activation, but either supplemental SFA or MUFA may contribute to chronic low-grade neuroinflammation. 相似文献
5.
A. Schneider B. Su T. W. Button L. Singleton O. Wilhelmi S. E. Huq P. D. Prewett R. A. Lawes 《Microsystem Technologies》2002,8(2-3):88-92
In this paper results are presented from a range of experiments to explore the feasibility of inserting a ceramic material
PZT (lead zirconium titanate) into different kinds of high-aspect-ratio resist moulds. Polymethylmethacrylate (PMMA) and SU-8
on silicon substrates and free-standing SU-8 membranes with micro-cavities or through-holes (defined by X-ray lithography)
have been used as moulding medium. Processing conditions for the resist materials including pre-bake, exposure, post-bake,
development and stripping have been compared. The advantages of different types of resist mould for the LIGA process has been
evaluated. Additionally a comparison of photosensitivity of PMMA and SU-8 has been carried out. Using a range of load pressures
(5 to 60 MPa), appropriate conditions for PZT embossing into resist moulds have been determined (ensuring minimum void formation
in the final PZT structures). In the final form, SU-8 moulds have been removed by laser ablation. This is the first reporting
of high-aspect-ratio ceramic microstructures fabricated using a combination of SU-8 moulds and PZT embossing.
Received: 10 August 2001/Accepted: 24 September 2001 相似文献
6.
7.
OBJECTIVE: Two related studies that evaluated the impact of a continuing education program about community-based rehabilitation on the performance of administrators, professionals, and paraprofessionals are presented. One study contained a second part that examined whether differences between pre-course test performance and post-course test performance might be accounted for by practice effects. DESIGN: Factorial mixed model designs. SETTING: University classroom. PARTICIPANTS: Three hundred and eight professionals, administrators, and paraprofessionals from a variety of community-based rehabilitation programs. INTERVENTION: The 4-day graduate-level course focused on three content areas: brain and behavior relationships, behavioral and cognitive intervention strategies, and a rehabilitation philosophy that emphasizes individual client rights. MAIN OUTCOME MEASURE: An examination completed before and immediately after taking the course. RESULTS: Professionals and administrators perform better than paraprofessionals when tested at the beginning and end of the training. However, the absolute differences among these groups were not substantial. In addition, the rate of learning course content was the same for administrators, paraprofessionals, and professionals. CONCLUSIONS: The results support the usefulness of training for all levels of staff and suggest that all levels of staff benefit in an equal fashion. 相似文献
8.
9.
We report a method which combines colloidal processing with polymer mould for the net shape fabrication of fine scale ceramic structures with feature sizes in the micrometer range and aspect ratios up to 10. Both soft and solid polymer moulds have been used, which can be made using lithography, laser micromachining or CNC machining. Fine scale ceramic structures are formed via embossing, moulding and casting. Polymer moulds are removed using either chemical or mechanical methods depending on the aspect ratio and feature size of the fine scale ceramic structures. Some fine scale ceramic structures have been demonstrated in examples such as PZT microrod arrays and alumina microgears. 相似文献
10.
Oxygen Vacancy Relaxation and Domain Wall Hysteresis Motion in Cobalt-Doped Barium Titanate Ceramics
Bo Lin Cheng Tim W. Button Maurice Gabbay Gilbert Fantozzi Mario Maglione 《Journal of the American Ceramic Society》2005,88(4):907-911
Mechanical and dielectric loss measurements were carried out in the BaTiO3 ceramics doped with Co at frequencies between 0.01 Hz and 1 MHz as a function of temperature from −150° to 150°C. The relaxation peak observed in the ferroelectric phase with an activation energy of 0.27 eV is assumed to be related to the motion of oxygen vacancies. This peak could be because of the reorientation of an electrical dipole made of oxygen vacancies and Co3+ ions in the lattice. Furthermore, another loss peak located just below the Curie temperature T c could be interpreted as hysteretic motion of the domain walls in a regime where the domain wall density is changing. 相似文献