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排序方式: 共有855条查询结果,搜索用时 396 毫秒
51.
WANG Zhanshan WANG Fengli ZHANG Zhong CHENG Xinbin QIN Shuji & CHEN Lingyan Institute of Precision Optical Engineering Department of Physics Tongji University Shanghai China 《中国科学G辑(英文版)》2005,48(5):559-574
With the development of the multiplayer technology, the multilayer mirrors have been widely used in many fields, such as the soft X-ray astronomical telescope, soft X-ray microscopy, extreme ultraviolet lithography, applications of synchrotron radiation, plasma diagnosis, and so on. However, in the hard X-ray region, especially for the wavelength shorter than 0.1 nm, the optical elements based on the traditional multilayers or the single high-Z metal coatings cannot accommodate the advancemen… 相似文献
52.
Lina Geng Tao Bo Huwei Liu Na Li Feng Liu Kean Li Junling Gu Ruonong Fu 《Chromatographia》2004,59(1-2):65-70
A new capillary coating of alternate -zirconium phosphate lysozyme fabricated for open-tubular electrochromatography enantioseparation. The chiral compounds D, L-tryptophan tested were enantiomerically resolved. The influences brought by experimental parameters, such as organic modifier, temperature, applied voltage and pH of running buffer on the performance of the column, were investigated. 相似文献
53.
The properties of multilayer metal-fiber coverings superimposed on plane base layers, which consist of various combinations of a copper mesh and different-length copper wires, are examined. Coverings from discrete copper microwires, two-layer coverings including a mesh and microwires, and three-layer coverings consisting of a mesh and two layers of microwire are investigated. The contacts between the fibers, the copper mesh, and the base layer are analyzed by using the metallography technique. Quantitative estimates for these contacts are presented. The side effects connected with the hydrogen disease of copper are discussed. The thermal properties of the porous structures are analyzed with the use of a termographic chamber. It is shown that the porous metal-fiber structures have good mechanical and heat-transfer properties. 相似文献
54.
ZhuJianxin 《高校应用数学学报(英文版)》2000,15(4):443-452
In this paper, a local orthogonal transformation is created to transform the Helmholtz waveguide with curved interface to the one with a flat interface within the two-layer medium, and the Helmholtz equation uxx uzz k^2(x,z)u=0 is transformed to Vxx αVzz βVz γV=0. Numerical results demonstrate that the transformation is more feasible. This transformation is particularly useful for the research on wave propagation in acoustic waveguide. 相似文献
55.
研究了Si3N4层在ZrN/Si3N4纳米多层膜中的晶化现象及其对多层膜微结构与力学性能的影响. 一系列不同Si3N4层厚度的ZrN/Si3N4纳米多层膜通过反应磁控溅射法制备. 利用X射线衍射仪、高分辨透射电子显微镜和微力学探针表征了多层膜的微结构和力学性能. 结果表明,由于受到ZrN调制层晶体结构的模板作用,溅射条件下以非晶态存在的Si3N4层在其厚度小于0.9 nm时被强制晶化为NaCl结构的赝晶体,ZrN/Si3N4纳米多层膜形成共格外延生长的柱状晶,并相应地产生硬度升高的超硬效应. Si3N4随层厚的进一步增加又转变为非晶态,多层膜的共格生长结构因而受到破坏,其硬度也随之降低. 相似文献
56.
制备了Nd28Fe66B6/Fe50Co50多层纳米复合磁性薄膜,对溅射态和650℃退火处理15 min试样的相成分分析和微结构的观察显示,溅射态薄膜呈非晶态,经650℃退火处理15 min后,薄膜主要相成分为硬磁性Nd2Fe14B相和软磁性相FeCo(110)相.Nd2Fe14B相呈柱状,其易磁化c轴垂直于膜面,尺寸约10 nm.在硬磁性相和软磁性相之间存在少量富Nd相和非晶态,富Nd相大小约7 nm.磁性测量和分析表明,1)该系列薄膜退火态具有垂直于膜面的磁晶各向异性.2)对于固定厚度(10 nm)层Nd-Fe-B和不同厚度(tFeCo=1—100 nm)层FeCo多层纳米复合膜,剩磁随软磁相FeCo 厚度的增加快速增加,而矫顽力则减小.当tFeCo=5 nm时,最大磁能积达到200 kJ/m3. 3)硬磁相Nd-Fe-B层和软磁相FeCo层之间交换耦合导致剩磁和磁能积增强.
关键词:
Nd-Fe-B/FeCo多层纳米复合膜
交换耦合
磁各向异性 相似文献
57.
We describe in this paper a design procedure for omnidirectional high reflectors with wide bandwidths for optical telecommunication
bands. From the numerical results achieved by the transfer matrix method, it is found that a partial omnidirectional high-reflector
covering the optical telecommunication wavelengths 1.3 and 1.55 μm is obtained for a partially deformed quarter-wave stack
air/H(LH)15/glass by using the tellurium as a material of high refractive index (n
H = 4.6). The partially deformed stack is a periodic system deformed by a power law y = x
1+k. Here y is the coordinates of the deformed object, x is the coordinates of the periodic stack and k is the coefficient defining the deformation degree. The study of this system leads to an omnidirectional high reflector band
covering the optical telecommunication wavelengths 1.3 and 1.55 μm for k = 0.2. 相似文献
58.
59.
Jinyuan Liu Deming Shu Yujie Wang Suresh Narayanan Ali Mashayekhi Jun Qian Jin Wang 《Journal of synchrotron radiation》2007,14(1):138-143
The development of a sagittally focusing double‐multilayer monochromator is reported, which produces a spatially extended wide‐bandpass X‐ray beam from an intense synchrotron bending‐magnet source at the Advanced Photon Source, for ultrafast X‐ray radiography and tomography applications. This monochromator consists of two W/B4C multilayers with a 25 Å period coated on Si single‐crystal substrates. The second multilayer is mounted on a sagittally focusing bender, which can dynamically change the bending radius of the multilayer in order to condense and focus the beam to various points along the beamline. With this new apparatus, it becomes possible to adjust the X‐ray beam size to best match the area detector size and the object size to facilitate more efficient data collection using ultrafast X‐ray radiography and tomography. 相似文献
60.
A set of Al/AlN multilayers with various modulation periods were prepared using DC magnetron sputtering method. Low angle X-ray diffraction (LAXRD) was used to analyze the layered structure of multilayers. The phase structure of the films was investigated with grazing angle X-ray diffraction (GAXRD). LAXRD results indicate that well-defined multilayer modulation structures are formed for the relatively larger modulation periods. However, the loss of mutilayered structure is detected in the multilayer with low modulation period. A very wide amorphous peak is observed in multilayer with modulation period of 4 nm. The multilayers show obvious crystallization at larger modulation periods, however, the diffraction peaks are much wider than the Al single layer because of the interruption of the continuous columnar grain growth by alternating deposition processes. Nanoindentation experiments were performed to study the mechanical properties as a function of multilayer modulation period. It is found that the hardness of the multilayers is greater than the hardness calculated from rule of mixtures. With the modulation periods adjusted, the multilayers are even harder than its hard component (AlN). A maximum hardness of 24.9 GPa, about 1.9 times larger than its hard component (AlN) and 3.7 times larger than the hardness calculated from the rule of mixtures, is found at the multilayer with modulation period of 16 nm. The wear test results show that the multilayers possess lower and stable friction coefficient, and superior wear properties. 相似文献