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Search Results: 1 - 10 of 42566 matches for " Pengshou Xu "
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Influence of the photon beam position on incident SR intensity at SXMCD endstation
Yuxian Guo,Pengshou Xu
Physics , 2013, DOI: 10.1088/1674-1137/37/12/128002
Abstract: A small fluctuation of the photon beam position will affect the characteristics of the synchrotron radiation (SR) intensity and polarization when it enters the end-station through the related beamline. In this paper, by changing the electron orbit equilibrium position in the vertical direction, we have measured the corresponding changes in the absorption strength of the SR with a gold mesh in different chopper aperture positions. It is found that for three aperture positions, the absorption intensity of the gold mesh shows a good Gaussian distribution as the photon beam position moves, while the ratio of the SR intensity passing through the upper and lower apertures shows a monotonous variation. This suggests a new method for estimating the circular polarization degree of SR originating from the bending magnet based on our current measurement.
Theoretical calculations on the atomic and electronic structure of β-SiC(110) surface
Changkun Xie,Pengshou Xu,Faqiang Xu,Haibin Pan
Chinese Science Bulletin , 2002, DOI: 10.1360/02tb9181
Abstract: We present a theoretical calculation of the atomic and electronic structure of β-SiC and its non-polar (110) surface using the full potential linear augmented plane wave (FPLAPW) approach. The calculated lattice constant and bulk modulus of β-SiC crystal are in excellent agreement with experimental data. The atomic and electronic structure of β-SiC(110) surface has been calculated by employing the slab and supercell model. It is found that the surface is characterized by a top-layer bond-length-contracting rotation relaxation in which the Si-surface atom moves closer towards the substrate while the C-surface atom moves outward. This relaxation is analogous to that of III-V semiconductor surface. The driving mechanism for this atomic rearrangement is that the Si atom tends to a planar sp2-like bonding situation with its three N neighbors and the N atom tends to a p3-like bonding with its three Si neighbors. Furthermore, surface relaxation induces the change from metallic to semiconducting characterization.
The spin and orbital moment contributions of each element to macroscopic magnetization in Co0.9Fe0.1 films
Yuxian Guo,Jie Wang,Honghong Li,Pengshou Xu,Jianwang Cai
Chinese Science Bulletin , 2006, DOI: 10.1007/s11434-006-2082-4
Abstract: Co-Fe alloy films have such properties as high saturation magnetization, high Curie temperature and low coercive force. It is of importance to study the origin of high saturation magnetization in these alloys. In this paper, we study the spin (m s) and orbital moments (m o) of Fe and Co in the Co0.9Fe0.1 film by using X-ray magnetic circular dichroism (XMCD) and SQUID magnetometry. The m s and m o for Co are 1.58 and 0.31 μB, and for Fe are 1.63 and 0.36 μB respectively. The average magnetic moment (1.90 μB) determined by XMCD is in agreement with that obtained from SQUID measurements. The total magnetic moment ratio of Fe to Co is 10.5:89.5, while the ratio of the spin to orbital moment is 83.4:16.6. Considering the separation of the spin and orbital moment, an outcome of m Fe-spin: m Fe-orbit: m Co-spin: m Co-orbit = 8.6:1.9:74.8:14.7 is obtained.
Synchrotron radiation photoemission study on growth of gadolinium film over Ni(110) surface
Faqiang Xu,Junfa Zhu,Yuming Sun,Xianfeng Wang,Erdong Lu,Pengshou Xu,Xinyi Zhang,Shuxian Zhuang
Chinese Science Bulletin , 1999, DOI: 10.1007/BF02885484
Abstract: The growth of Gd film on Ni (110) surface was studied by synchrotron radiation photoemission spectroscopy and XPS techniques. It is revealed that in the coverage range of 0–0.22 nm Gd4f core level showed a single-peak structure, therefore Gd film grows over Ni(110) in the layer-by-layer mode. However, when Gd coverage was larger than 0.22 nm the Gd4f peak turned gradually into double-peak and a double-peak structure with 2.3 eV separation was formed at 1.51 nm, meanwhile similar phenomenon was observed in the Gd4d XPS spectra. It is suggested that the double-peak structure of Gd4f was derived from the growth of Gd film in cluster mode and the Gd atomic clusters may exhibit different electronic states from Gd metal owing to their special structures. The Gd4f double-peak e-volved into a single-peak on annealing at 600 K, implying that Gd clusters are thermodynamically unstable.
Synchrotron radiation photoemission study on growth of gadolinium film over Ni(110) surface

Faqiang Xu,Junfa Zhu,Yuming Sun,Xianfeng Wang,Erdong Lu,Pengshou Xu,Xinyi Zhang,Shuxian Zhuang,

科学通报(英文版) , 1999,
Abstract: The growth of Gd film on Ni (110) surface was studied by synchrotron radiation photoemission spectroscopy and XPS techniques. It is revealed that in the coverage range of 0–0.22 nm Gd4f core level showed a single-peak structure, therefore Gd film grows over Ni(110) in the layer-by-layer mode. However, when Gd coverage was larger than 0.22 nm the Gd4f peak turned gradually into double-peak and a double-peak structure with 2.3 eV separation was formed at 1.51 nm, meanwhile similar phenomenon was observed in the Gd4d XPS spectra. It is suggested that the double-peak structure of Gd4f was derived from the growth of Gd film in cluster mode and the Gd atomic clusters may exhibit different electronic states from Gd metal owing to their special structures. The Gd4f double-peak e-volved into a single-peak on annealing at 600 K, implying that Gd clusters are thermodynamically unstable.
A Study of ZnO/Si (111) Interface Structure by Synchrotron Radiation X-Ray Grazing Incident Diffraction
ZnO/Si (111)界面结构的同步辐射掠入射X射线衍射研究

Zhao Chaoyang,Li Ruipeng,Sun Bai,Xu Pengshou,Zhang Guobin,Pan Guoqiang,
赵朝阳
,李锐鹏,孙柏,徐彭寿,张国斌,潘国强

半导体学报 , 2007,
Abstract: 在不同的衬底温度下,用脉冲激光沉积(PLD)方法制备了c轴高度取向的ZnO薄膜.采用同步辐射掠入射X射线衍射(GID)技术研究了ZnO薄膜与Si(111)衬底的界面结构.GID结果表明:不管衬底温度是500℃还是300℃,在无氧气氛下用PLD方法制备的ZnO外延膜均处于压应力状态,且随着X射线探测深度的增加,应力增大.结合常规X射线衍射技术,计算了薄膜内的双轴应力;给出了样品的泊松比和c/a值,得出两样品均接近理想的六方密堆积结构,偏离标准的ZnO值.综合各方面实验结果,说明衬底温度控制在500℃时生长的ZnO薄膜具有较好的晶体质量.
Natural Passivity of Amorphous Fe_(40)Ni_(40)P_(14)B_6 and Fe_(54.6)Ni_(38)Si_(4.1)B_(2.3)V_1 Alloys
Erdong LU,Pengshou XUMingrong JI,Maosheng MA,Xianming LIU,

材料科学技术学报 , 1994,
Abstract: The natural passive films forrned on Fe_(40)Ni_(40)P_(14)B_6 and Fe_(54.6)Ni_(38)Si_(4.1)B_(2.3)V_1 amorphous alloys long-term exposed in air have been studied by X-ray photoelectron spectroscopy (XPS) and Auger electron (including Ar+ ion depth profiling) spectroscopy (AES). The following aspects have been investigated: (1) chemical states of the elements in the films. binding energies and the chemical shifts measured by XPSf (2) structure and composition of the films fand (3) thickness of the passive films determined by AES depth profiling and XPS analysis.
A Decision Problem of Hotels on Setting Online-Exclusive-Rooms in E-Commerce Age  [PDF]
Liang Xu, Xiaoyan Xu
Journal of Service Science and Management (JSSM) , 2014, DOI: 10.4236/jssm.2014.74029
Abstract:

Due to the rapid development of information technology, customers’ consumption pattern in hotel industry has dramatically changed, and many people book rooms through some professional online platforms. Hotel managers need to redesign their sale channel structures by incorporating online platforms, in order to increase profit. This paper focuses on a revenue maximization problem for a hotel which cooperates with an online platform. Two cooperating forms are investigated and compared. Specifically, one intuitive form is named complete sharing, in which all the hotel rooms are shared with the online platform for booking. The other form is named setting online-exclusive-rooms (OERs), in which the hotel set a fixed quantity of rooms for exclusively booking from the online platform. By building a loss queueing model, this paper finds some properties of the optimal quantity of OERs in the latter form. Factors affecting the selection and how they affect the selection are also investigated.

An Algorithm for Improving Throughput Guarantee of Topology-Transparent MAC Scheduling Strategy  [PDF]
Chaonong Xu
Wireless Sensor Network (WSN) , 2010, DOI: 10.4236/wsn.2010.210096
Abstract: Topology-transparent MAC scheduling strategies nowadays are all based on combinatorial design. To get throughput guarantee, a cover-free set is output as scheduling strategy of network. In this paper, we aim to modify the cover-free set so that better throughput can be guaranteed. At the first step, the redundant slot of the cover-free set is proposed and found to have negative influence on the minimal guaranteed throughput. Second, we prove that any subset of a cover-free set is still a cover-free set after its redundant slots were squashed out. Our algorithm chooses the subset which has the maximal number of redundant slots, squashes all of its redundant slots, and then designates it as the network scheduling strategy. Therefore, better through- put can be guaranteed if the squashed subset is adopted as network scheduling strategy. For any topology- transparent node scheduling strategy, both the increased minimal throughput and decreased maximal transmission delay can be gotten by just using our algorithm as an extra accessory.
Experimental and Numerical Study of the Effect of Surround Protection Technique on the Strain Measurement for Offshore Jacket Platform  [PDF]
Yongjun Xu
Engineering (ENG) , 2011, DOI: 10.4236/eng.2011.35056
Abstract: For strain measurement on offshore jacket platform in deep water, waterproof of strain foil is always an important issue, especially, due to the high pressure in deep water. The waterproof is difficult in two places, one is between the matrix structure and the protection structure, and another is between the lead wires and the protection structure. The surround protection technique discussed in this paper is conventional and ideal, and can be operative for a long time, up to five years. In this method, a metal case and tube is added on the local position, which increases the local rigidity, but the effect on the measurement of strain is not well studied. In this paper, the effect of the surround protection technique on the strain measurement is studied by using numerical and experimental methods, and the results show that the measurement error is well in the range permitted by engineering practice.
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