全文获取类型
收费全文 | 196篇 |
免费 | 33篇 |
国内免费 | 4篇 |
专业分类
化学 | 19篇 |
晶体学 | 5篇 |
数学 | 3篇 |
物理学 | 206篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 2篇 |
2013年 | 14篇 |
2012年 | 15篇 |
2011年 | 16篇 |
2010年 | 29篇 |
2009年 | 22篇 |
2008年 | 11篇 |
2007年 | 15篇 |
2006年 | 12篇 |
2005年 | 20篇 |
2004年 | 11篇 |
2003年 | 12篇 |
2002年 | 5篇 |
2001年 | 5篇 |
2000年 | 6篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 9篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1989年 | 1篇 |
1988年 | 2篇 |
排序方式: 共有233条查询结果,搜索用时 15 毫秒
1.
The preparation process, crystallinity and electrical properties of pulse laser deposited Pb(ZrxTi1−x)O3 (PZT) thin films were investigated in this paper. PZT (x = 0.93) thin film samples deposited at different substrate temperatures were prepared. Si (1 1 0) was the substrate; Ag and YBCO were the top electrode and the bottom electrode respectively. The bottom electrode YBCO was deposited on the Si substrate by pulsed laser deposition (PLD), and then PZT was epitaxially deposited on YBCO also by PLD. After annealing, the top electrode Ag was prepared on PZT by thermal evaporation, and then the Ag/PZT/YBCO/Si structured thin films were obtained. The XRD and the analysis of their electrical characters showed that, when the substrate temperature was elevated from 600 °C to 800 °C, the crystallinity and electrical properties of PZT thin films became better and better, and the FR(LT)–FR(HT) phase transition of PZT (x = 0.93) thin films occurred at 62 °C. The PZT film deposited at 800 °C had the best pyroelectric properties, and when the FR(LT)–FR(HT) phase transition of this film occurred, the peak value of pyroelectric coefficient (p) was obtained, with a value of 1.96 × 10−6 C/(cm2 K). The PZT film deposited at 800 °C had the highest remnant polarization (Pr) and the lowest coercive field (Ec), with the values of 34.3 μC/cm2 and 41.7 kV/cm respectively. 相似文献
2.
3.
Hua Zhang Jian YangHuizhou Liu Shuming Wang 《Physica C: Superconductivity and its Applications》2010,470(22):1998-2001
This paper reports CeO2/YSZ/Y2O3 buffer layers deposited on biaxially textured NiW substrates by DC reactive sputtering in a reel-to-reel system. The effect of partial pressure of water vapor (PH2O) on surface morphology and orientation of the Y2O3 films was examined. The obtained CeO2/YSZ/Y2O3 buffer layers exhibit a highly biaxial texture, with in- and out-of-plane FWHM values respectively in the range of 6.0–7.0° and 4.5–5.5°. Crystallographic consistency of CeO2/YSZ/Y2O3 along meter length is excellent. Atomic force microscope observation (AFM) reveals a smooth, continuous and crack-free surface with a Root-mean-square roughness (RMS) lower than 10 nm. 相似文献
4.
H. Huhtinen M. Irjala P. PaturiM. Falter 《Physica C: Superconductivity and its Applications》2012,472(1):66-74
The effect of BaZrO3 (BZO) doping is systematically studied in YBa2Cu3O6+x (YBCO) thin films deposited by pulsed laser deposition (PLD) on buffered NiW substrates. Based on the structural and magnetic properties, the optimal BZO doping concentration is obtained to vary between 4 and 7.5 wt.%, depending mainly on applied magnetic field. This relatively high optimal concentration is linked to the nanograined target material and metal substrate that cause low-angle grain-boundaries and in-plane spread of YBCO crystals on NiW. Thickness dependent analysis of undoped and BZO-doped YBCO films predicts differences in growth mechanisms where early growth next to the substrate interface is 2D-type in BZO-doped films. This leads to the situation where crystallographic structure as well as superconducting properties are improved when the film develops and the thickness is increased. Therefore from the resistivity measurements a threshold thicknesses where reasonable properties occur are determined for both set of films. Measurements in thermally activated flux-flow regime (TAFF) indicate that above the threshold thickness relatively strong and isotropic vortex pinning is realized in BZO-doped YBCO films. Generally, this paper demonstrates that especially for thin film applications on NiW substrates even more compatible buffer layer structures should be utilized. 相似文献
5.
6.
7.
以YBa_(2)Cu_(3)O_(7)(YBCO)带材为代表的二代高温超导带材被广泛应用于各类超导装备中,由于YBCO超导带材生产长度的限制,其接头技术将在带材的实用化发展中起到至关重要的作用,其中低熔点焊料焊接接头技术由于其工艺简单且能够满足目前二代高温超导材料的应用需求,成为现阶段接头制备的主流技术.本文基于YBCO基本属性,结合目前国内外的YBCO带材生产现状,系统全面地调研了低熔点焊料焊接接头技术的制作工艺及其性能的影响因素,明确了低熔点焊料焊接接头的关键影响因素,梳理了二代高温超导带材接头的焊接工艺流程,为二代高温超导带材接头的制备提供参考。 相似文献
8.
本文通过在前驱液中添加过量钇盐和铈的有机盐,采用三氟乙酸盐-金属有机沉积法(TFA-MOD) 在铝酸镧单晶基体上制备了含有纳米氧化钇和纳米铈酸钡的YBCO薄膜. 与纯YBCO薄膜相比,掺杂Y2O3/BaCeO3的YBCO膜的临界转变温度几乎保持不变,为91 K左右. 而掺杂Y2O3/BaCeO3的YBCO膜的临界电流密度达到5.0 MA/cm2 (77 K, 0T), 是纯YBCO膜临界电流密度的1.5倍.薄膜中的Y2O3和BaCeO3可能在YBCO内部起到了 有效的钉扎磁通作用.
关键词:
钇钡铜氧薄膜
2O3和纳米BaCeO3')" href="#">纳米Y2O3和纳米BaCeO3
磁通钉扎
三氟乙酸盐-金属有机沉积 相似文献
9.
10.
为了制作能满足YBCO涂层导体(coated conductor)所需要的高强度、低磁性的立方织构基带,本工作用粉末冶金方法制作了Ni-5at%W合金基带.为评估基带中立方织构的发展,用March-Dollase函数对各种热处理样品的择优取向度进行了研究,结果与用X射线极图法和电子背散射衍射法得到的结果基本一致.研究结果表明,在实验中所用的工艺参数范围内,随总加工率和热处理温度的提高,基带中立方织构百分数明显增高.提高总加工率实际增加了冷加工样品中立方织构晶粒或立方核心的数量.实验中得到了较好的和实用的工艺制度,用这种工艺可以制作出具有99%~100%立方织构百分数,并具有很好一致取向度的Ni5W基带. 相似文献