On the spectral sequence constructors of Guichardet and Stefan

The concept of a spectral sequence constructor is generalised to Hopf Galois extensions. The spectral sequence constructions that are given by Guichardet for crossed product algebras are also generalised and shown to provide examples. It is shown that all spectral sequence constructors for Hopf Galois extensions construct the same spectral sequence.     

Pulsed reactive crossed beam laser ablation of La0.6Ca0.4CoO3 using O: Where does the oxygen come from?

The composition of thin perovskite films, especially the oxygen content, is a crucial parameter which influences many physical properties, such as conductivity and catalytic activity. Films produced by pulsed laser deposition are normally annealed in an oxygen atmosphere after deposition to achieve a desired oxygen content. In pulsed reactive crossed beam laser ablation, no annealing step is necessary, but a fundamental question regarding this deposition technique is still open: where does the oxygen in the films come from?There are three possibilities, i.e. from the target, from the gas background, or from the gas pulse. To answer this question two experiments were performed: ¹⁸O₂ was used during the deposition process as background gas with ¹⁶O anions in the target and ¹⁶O₂ gas pulse, and a ¹⁸O₂ gas pulse with ¹⁶O from the target and background. These experiments revealed that the quantification of the oxygen origin is only possible, when no oxygen exchange occurs at the deposition temperature. The films are characterized after deposition by elastic recoil detection analysis (ERDA) to determine the ¹⁶O/¹⁸O ratio. Experiments with different oxidizing species in the gas pulse (N₂O and O₂) confirm that the oxidizing potential (N₂O > O₂) as well as the number of molecules are important.     

变参数波振器中小信号增益公式

利用微扰展开技术推导出变参数波振器的小信号增益两个近似求积表达式并将其计算结果与数值模拟结果进行了比较,二者吻合很好。利用近似解析式对小信号增益进行了初步探讨,得到了电子入射能量可低于初始谐振能,能散度允许范围受波振器设计影响以及降低锥度改变率可提高小信号增益等新结论。     

A remark on Mansfield's imprimitivity theorem

We show that the Morita equivalence part of Mansfield's Imprimitivity Theory can be obtained by Green's Imprimitivity Theorem (and duality theory).

     

Quantitative surface analysis by Auger and x-ray photoelectron spectroscopy

Recent developments in quantitative surface analysis by Auger (AES) and x-ray photoelectron (XPS) spectroscopies are reviewed and problems relating to a more accurate quantitative interpretation of AES/XPS experimental data are discussed. Special attention is paid to consideration of elementary physical processes involved and influence of multiple scattering effects on signal line intensities. In particular, the major features of core-shell ionization by electron impact, Auger transitions and photoionization are considered qualitatively and rigorous approaches used to calculate the respective transition probabilities are analysed. It is shown that, in amorphous and polycrystalline targets, incoherent scattering of primary and signal Auger and photoelectrons can be described by solving analytically a kinetic equation with appropriate boundary conditions. The analytical results for the angular and energy distribution, the mean escape depth, and the escape probability as a function of depth of origin of signal electrons as well as that for the backscattering factor in AES are in good agreement with the corresponding Mote Carlo simulation data. Methods for inelastic background subtraction, surface composition determination and depth-profile reconstructions by angle-resolved AES/XPS are discussed. Examples of novel techniques based on x-ray induced photoemission are considered.     

A Crossed Immunoelectrophoretic Technique for the Detection of the Down's Syndrome Protein

Abstract

The sera of seventy-one women and twenty-six men of various ages were examined by a two dimensional (crossed) immunoelectrophoresis technique which was modified to detect a protein (the Down's Syndrome protein) originally found in the sera of mothers of trisomy 21 children. The sensitivity of the method is reported to be 0.1 to 1.0 mg/L. Modifications included use of a Tris-Tricine buffer, high voltage in the second dimension, and relatively low antibody concentration to allow easy detection of the Down's Syndrome (DS) protein.

Of twenty-eight mothers and twelve fathers of trisomy 21 children, eighteen mothers and five fathers were positive, while of forty-three women and fourteen men having unaffected or no children, only seven women and two men were positive for the DS protein.

Since the presence of the Down's Syndrome protein may indicate a propensity for giving birth to a trisomy 21 affected child, this crossed immunoelectrophoretic technique may be used as a screening procedure for the DS protein and, therefore, as a tool in genetic counseling.     

Constructing the Co cyclic Structures for Crossed Copro duct Coalgebras

In this paper, we construct a cocylindrical object associated to two coal-gebras and a cotwisted map. It is shown that there exists an isomorphism between the cocyclic object of the crossed coproduct c...     

A combined crossed molecular beam and quasiclassical trajectory study of the Titan-relevant N(2D) + D2O reaction

Following a recent investigation on the N(²D) + H₂O reaction [Homayoon et al., J. Phys. Chem. Lett. 5, 3508 (2014)], we report on an experimental and theoretical study of the isotopologue N(²D) + D₂O reaction. Crossed molecular beam (CMB) experiments were conducted at a collision energy of 10.3 kcal mol^–1. Quasiclassical trajectory calculations were performed on a recent potential energy surface to derive the centre-of-mass functions necessary to simulate the CMB laboratory distributions. Excellent agreement was found. The importance of the channel leading to HON/DON was confirmed. The inclusion of this channel, in addition to that leading to the isomer HNO/DNO, can affect the models considering the coupling between nitrogen and oxygen chemistry in the upper atmosphere of Titan.     

Undulator with permanent ferrimagnetic magnets

Undulator for terahertz FEL is created of ferrite materials. The length of the undulator period is 9 cm and the number of periods is 27. By means of selection and redistribution of magnetic elements it was succeeded to reduce the spread in amplitudes of the magnetic field down to 7%. Additional windings in magnetic elements were used to compensate for the residual spread. The needed focusing gradient of the magnetic field is obtained by means of relative displacement, along the x-axis, of alternating poles with opposite signs of the magnetic field. The undulator parameters, including the properties of focusing in the horizontal plane, are studied.     

Influence of higher harmonics of the undulator in X‐ray polarimetry and crystal monochromator design

The spectrum of the undulator radiation of beamline P01 at Petra III has been measured after passing a multiple reflection channel‐cut polarimeter. Odd and even harmonics up to the 15th order, as well as Compton peaks which were produced by the high harmonics in the spectrum, could been measured. These additional contributions can have a tremendous influence on the performance of the polarimeter and have to be taken into account for further polarimeter designs.