全文获取类型
收费全文 | 262篇 |
免费 | 63篇 |
国内免费 | 14篇 |
专业分类
电工技术 | 34篇 |
综合类 | 32篇 |
化学工业 | 12篇 |
金属工艺 | 19篇 |
机械仪表 | 31篇 |
建筑科学 | 3篇 |
矿业工程 | 6篇 |
能源动力 | 8篇 |
石油天然气 | 2篇 |
武器工业 | 4篇 |
无线电 | 51篇 |
一般工业技术 | 91篇 |
冶金工业 | 13篇 |
原子能技术 | 1篇 |
自动化技术 | 32篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 7篇 |
2020年 | 14篇 |
2019年 | 12篇 |
2018年 | 10篇 |
2017年 | 28篇 |
2016年 | 24篇 |
2015年 | 18篇 |
2014年 | 11篇 |
2013年 | 16篇 |
2012年 | 13篇 |
2011年 | 20篇 |
2010年 | 12篇 |
2009年 | 9篇 |
2008年 | 9篇 |
2007年 | 17篇 |
2006年 | 7篇 |
2005年 | 4篇 |
2004年 | 10篇 |
2003年 | 13篇 |
2002年 | 12篇 |
2001年 | 20篇 |
2000年 | 13篇 |
1999年 | 15篇 |
1998年 | 10篇 |
1997年 | 6篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
排序方式: 共有339条查询结果,搜索用时 15 毫秒
31.
软磁材料中存在巨磁阻抗 (giantmagneto impedance ,GMI)效应以及与之相同来源的应力阻抗 (stress impedance ,SI)效应 ,利用这两种效应可以制成具有高灵敏度的微型化的磁场和应力 应变传感器。本文基于传感器的实际应用 ,对图形化的、较大磁致伸缩的FeSiB单层和多层薄膜的巨磁阻抗和应力阻抗效应中频率和退火的影响进行了研究。结果表明 ,对于两种效应 ,经过退火处理的单层和多层膜均可在较低的频率下得到较高的灵敏度 ,而多层膜中的应力阻抗效应将为新型高灵敏传感器的设计和研制开辟一条崭新的途径 相似文献
32.
33.
34.
Meneses-Rodríguez D Ferreiro-Vila E Prieto P Anguita J González MU García-Martín JM Cebollada A García-Martín A Armelles G 《Small (Weinheim an der Bergstrasse, Germany)》2011,7(23):3317-3323
A Co nanolayer is used as a local probe to evaluate the vertical inhomogeneous distribution of the electromagnetic (EM) field within a resonant metallic nanodisk. Taking advantage of the direct relation between the magneto-optical activity and the electromagnetic field intensity in the Co layer, it is shown that the nonuniform EM distribution within the nanodisk under plasmon resonant conditions has maximum values close to the upper and lower flat faces, and a minimum value in the middle. 相似文献
35.
对小型型钢轧制生产线码垛区设立的翻转电磁头平面四连杆机构,作出简化模型,进行驱动力矩和运动速度的计算分析,并且作图直观显示速度变化情况,分析结果符合现场使用要求. 相似文献
36.
软磁薄带巨磁阻抗效应的数值分析 总被引:1,自引:0,他引:1
利用磁畴壁移动模型以纳米晶软磁合金Fe73.5Cu1Nb3Si13.5B9为例对软磁薄带中的巨磁阻抗效应进行了数值分析,结果发现不同的磁导率机制并不能显著发迹巨巨磁阻抗效的大小仅由磁导率对外加磁场的敏感性决定,从趋肤深度的角度讨论了巨磁阻抗效应的频率特性。 相似文献
37.
Ana Espinosa Javier Reguera Alberto Curcio lvaro Muoz‐Noval Christian Kuttner Aurore Van de Walle Luis M. Liz‐Marzn Claire Wilhelm 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(11)
Progress of thermal tumor therapies and their translation into clinical practice are limited by insufficient nanoparticle concentration to release therapeutic heating at the tumor site after systemic administration. Herein, the use of Janus magneto‐plasmonic nanoparticles, made of gold nanostars and iron oxide nanospheres, as efficient therapeutic nanoheaters whose on‐site delivery can be improved by magnetic targeting, is proposed. Single and combined magneto‐ and photo‐thermal heating properties of Janus nanoparticles render them as compelling heating elements, depending on the nanoparticle dose, magnetic lobe size, and milieu conditions. In cancer cells, a much more effective effect is observed for photothermia compared to magnetic hyperthermia, while combination of the two modalities into a magneto‐photothermal treatment results in a synergistic cytotoxic effect in vitro. The high potential of the Janus nanoparticles for magnetic guiding confirms them to be excellent nanostructures for in vivo magnetically enhanced photothermal therapy, leading to efficient tumor growth inhibition. 相似文献
38.
基于磁介质听传输短的边界矩阵处理方法,建立了多层旋磁介质材料耦合法拉第角计算模型,分析了BiDyIG多层石榴石旋磁薄法拉第角频谱、结果表明分层「Bi:DyIG/Al」材料在300-580nm波长范围具有中的法拉第效应,这有有利于短波高密度磁光记录和微波法拉第器件性能改善。 相似文献
39.
In this article, a novel substrate integrated low‐profile dual‐band magneto‐electric (ME) dipole antenna is proposed. The entire antenna is constructed by four‐layer printed circuit boards (PCBs). Consequently, the height of the proposed antenna is decreased from 0.25λ0 to 0.11λ0 (λ0 is the free‐space wavelength at 5.5 GHz). By introducing rectangular patches with different sizes as electric dipoles, dual operating bands are achieved. Meanwhile, for the purpose of improving the impedance matching at the lower frequency band, a pair of complementary split‐ring resonators (CSRRs) is etched on the larger rectangular patches. Moreover, the short walls composed of plated through holes operate as a magnetic dipole. The antenna is fed by an equivalent wideband microstrip‐to‐parallel stripline balun. The results show that the antenna obtains dual bandwidths of 4.31‐4.71 GHz (8.8%) and 5.07‐5.89 GHz (14.9%) with VSWR <2, which can be applied for C‐band and 5G WiFi. Over the dual operating bands, stable gain and unidirectional radiation patterns with low polarization and low back lobe are also obtained. 相似文献
40.
Jerome Vernieres Stephan Steinhauer Junlei Zhao Audrey Chapelle Philippe Menini Nicolas Dufour Rosa E. Diaz Kai Nordlund Flyura Djurabekova Panagiotis Grammatikopoulos Mukhles Sowwan 《Advanced functional materials》2017,27(11)
Magnetron‐sputtering inert‐gas condensation is an emerging technique offering single‐step, chemical‐free synthesis of nanoparticles with well‐defined morphologies optimized for specific applications. In this study, the authors report a flexible approach to produce Fe nanocubes as building blocks for high‐performance NO2 gas sensor devices, and hybrid FeAu nanocubes with magneto‐plasmonic properties. Considering that nucleation happens within a short distance from the sputtering target, the authors utilize the high‐permeability and resultant screening effect induced by magnetic Fe targets of various thicknesses to manipulate the magnetic field configuration and plasma confinement. The authors thus readily switch from bimodal to single‐Gaussian size distributions of Fe nanocubes by modifying their primordial thermal environments, as explained by a combination of modeling methods. Simultaneously, the authors obtain a material yield increase of more than one order of magnitude compared to experiments using postgrowth mass filtration. The effectiveness of the method is demonstrated by the deposition of Fe nanocubes on microhotplate devices, leading to unprecedented NO2 detection performance for Fe‐based chemoresistive gas sensors. The exceedingly low detection limit down to 3 ppb is attributed to a morphological change in operando from Fe/Fe‐oxide core/shell to specific hollow‐nanocube structures, as revealed by in situ environmental transmission electron microscopy. 相似文献