scholarly journals Inside the Matrix: Crystal Structure of a Xyloglucan Endotransglycosylase

2004 ◽  
Vol 16 (4) ◽  
pp. 792-793 ◽  
Author(s):  
Nancy A. Eckardt
1993 ◽  
Vol 329 ◽  
Author(s):  
Vivien D.

AbstractIn this paper the relationships between the crystal structure, chemical composition and electronic structure of laser materials, and their optical properties are discussed. A brief description is given of the different laser activators and of the influence of the matrix on laser characteristics in terms of crystal field strength, symmetry, covalency and phonon frequencies. The last part of the paper lays emphasis on the means to optimize the matrix-activator properties such as control of the oxidation state and site occupancy of the activator and influence of its concentration.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Shilei Li ◽  
Yangyang Zhang ◽  
Jian’an Liu ◽  
Juanjuan Han ◽  
Ming Guan ◽  
...  

1999 ◽  
Vol 55 (4) ◽  
pp. 695-699 ◽  
Author(s):  
David H. Templeton

Equations derived from a statistical model and valid for all space groups give estimates of the elements of the matrix for least-squares refinement of atomic coordinates and isotropic thermal parameters for a large crystal structure with many diffraction data. The elements are functions of the lengths and directions of Patterson vectors and the distribution of weights as a function of Bragg angle. For a large data set, this matrix, or a portion of it, can be calculated in a time that is approximately proportional to the number of elements calculated and independent of the number of reflections.


2009 ◽  
Vol 2 ◽  
pp. BTRI.S3728 ◽  
Author(s):  
Aida Elkayar ◽  
Yehia Elshazly ◽  
Mariana Assaad

The objective of this work was to study the production of hydroxyapatite (HA) from bovine teeth. Hydroxyapatite (HA) was produced from bovine teeth powder after calcination at 1150 °C. It was discovered that the sample preparation process influences its properties, so, crystal structure and thermal stability of HA were investigated. The X-Ray diffraction analysis (XRD) results confirmed that HA has been successfully produced. Fourier transform infrared spectroscopic (FT-IR) study confirmed the presence of hydroxyl (OH) and phosphate (PO4−3) functional groups. The scanning electronic microscope (SEM) was employed to identify the surface morphology of HA, and showed the nanoporous structure throughout the matrix. The sample constituents such as Ca, P, K … etc., and their values were determined by Energy dispersive X-Ray (EDX).


2007 ◽  
Vol 561-565 ◽  
pp. 2305-2308
Author(s):  
Masaaki Nishiyama ◽  
Daisuke Hamatani ◽  
Kenji Matsuda ◽  
Tokimasa Kawabata ◽  
Yasuhiro Uetani ◽  
...  

There have been many reports about the bainitic phase decomposition of annealed Cu-Zn alloy. During annealing at 523 K, the hardness of this alloy increased at the early stage of annealing, although the β-phase couldn't be observed in the matrix of β'-phase (CsCl). The crystal structure of β' phase, thus, was investigated by a high-resolution transmission electron microscopy (HRTEM) to find its structural change. As the result, the striations were observed in the HRTEM image of matrix at the early stage of annealing. The selected area diffraction pattern was also obtained from this area, and it showed the extra streaks which couldn't be explained by the normal CsCl structure of the β’-phase.


2012 ◽  
Vol 503-504 ◽  
pp. 525-528
Author(s):  
Shu Zhang ◽  
Lei Meng

via completely after heat-treatment, [111] orientation of single crystal alloy structure is still cubic  phase at way coherency are ordered in matrix g panel and the direction rules arrangement; In high temperature and tensile stress creep period, with stress axes ordered  has formed certain Angle raft shape organization, creep later in nearly fracture zone, raft shape  ordered caring and distortion in happen, with strain increases, coarsening and distorted aggravating, until the present wavy shape; During the creep [111] orientation of single crystal alloys deformation characteristics is a wrong in  matrix channel to sports and shear raft shape  phase, due to form larger, more variable dislocation cut ordered after raft shape , occurred in dislocation bunch of sets and its formation and crystal structure; Among them, the matrix channel to inherit the maximum shear dislocation slip is made of alloy with larger strain rate main reason.


2014 ◽  
Vol DMTCS Proceedings vol. AT,... (Proceedings) ◽  
Author(s):  
Glenn Appleby ◽  
Tamsen Whitehead

International audience Knutson and Tao's work on the Horn conjectures used combinatorial invariants called hives and honeycombs to relate spectra of sums of Hermitian matrices to Littlewood-Richardson coefficients and problems in representation theory, but these relationships remained implicit. Here, let $M$ and $N$ be two $n ×n$ Hermitian matrices. We will show how to determine a hive $\mathcal{H}(M, N)={H_ijk}$ using linear algebra constructions from this matrix pair. With this construction, one may also define an explicit Littlewood-Richardson filling (enumerated by the Littlewood-Richardson coefficient $c_μν ^λ$ associated to the matrix pair). We then relate rotations of orthonormal bases of eigenvectors of $M$ and $N$ to deformations of honeycombs (and hives), which we interpret in terms of the structure of crystal graphs and Littelmann's path operators. We find that the crystal structure is determined \emphmore simply from the perspective of rotations than that of path operators.


Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4119
Author(s):  
Hongtao Jiang ◽  
Xiaohong Zhang ◽  
Junguo Gao ◽  
Ning Guo

Low-density polyethylene (LDPE) is one of the most comprehensive products used as insulation materials in power equipment. How to improve its dielectric properties by doping inorganic particles in LDPE has always been the focus of many researchers. In this paper, silica (SiO2) particles and montmorillonite (MMT) particles were added to LDPE, the order of adding particles was changed, and different micro-nano composites was made. The crystallization characteristics of composites were analyzed, the curves of the conductance current with the change of field intensity were analyzed, and the space charge distribution of each material were investigated. The results of crystallization show that the crystalline properties and crystallinity of the composites are higher than the matrix LDPE, the addition of SiO2 particles increases the composites’ crystallinity significantly, and the intercellular spacing of micro-nano composites is the smallest among all materials. The curve of conductance current versus electric field intensity shows that the tightness of the crystal structure can effectively hinder the movement of the molecular chain, inhibit carrier migration, while shortening the free travel of electrons, thereby reducing the electric conduction current of the material. The experimental results of the space charge accumulation curve further show that the compact crystal structure of the material is beneficial to the dissipation of space charge in the dielectric.


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