Study into structure change of deep buried clay during triaxial high pressure unloading test by CT

2004 ◽  
pp. 487-492
Author(s):  
Wenping Li ◽  
Xiaoqin Li ◽  
Zhiyong Zhang ◽  
Ruhua Sun ◽  
Weili Wang ◽  
...  
Keyword(s):  
High Pressure ◽  
Structure Change

Study into structure change of deep buried clay during triaxial high pressure unloading test by CT

2004 ◽  
pp. 487-491
Author(s):  
Zhiyong Zhang ◽  
Weili Wang ◽  
Xiaoqin Li ◽  
Ruhua Sun ◽  
Wenping Li ◽  
...  
Keyword(s):  
High Pressure ◽  
Structure Change

Crystal structure change of katoite, Ca3Al2(O4D4)3, with temperature at high pressure

2018 ◽  
Vol 46 (5) ◽  
pp. 459-469
Author(s):  
Atsushi Kyono ◽  
Masato Kato ◽  
Asami Sano-Furukawa ◽  
Shin-Ichi Machida ◽  
Takanori Hattori
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Structure Change

scholarly journals Coal Matrix Deformation and Pore Structure Change in High-Pressure Nitrogen Replacement of Methane

Energies ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 175 ◽  
Author(s):  
Xiaofeng Ji ◽  
Dangyu Song ◽  
Xiaoming Ni ◽  
Yunbo Li ◽  
Haotian Zhao
Keyword(s):  
High Pressure ◽  
Pore Structure ◽  
Structure Change ◽  
Coal Matrix ◽  
Matrix Deformation

MOLECULAR DYNAMIC SIMULATIONS OF SOLID NITROMETHANE UNDER HIGH PRESSURES

2010 ◽  
Vol 09 (01) ◽  
pp. 315-325 ◽  
Author(s):  
FENG GUO ◽  
HONG ZHANG ◽  
XINLU CHENG
Keyword(s):  
Hydrogen Bond ◽  
High Pressure ◽  
Hydrogen Bonding ◽  
Molecular Dynamic ◽  
High Pressures ◽  
High Explosive ◽  
Structure Change ◽  
Molecular Dynamic Simulations ◽  
Dynamic Simulations ◽  
Explosive Materials

We report ReaxFF molecular dynamic simulations of structure change of crystalline nitromethane and the formation of hydrogen bond under high pressure. Under high pressure, the angles between C–N bonds and X, Y and Z axes have changed. Through the calculation of g(r) of O and H atoms, we found a new peak near 1.6 Å, which indicates the formation of the hydrogen bond between O and H atoms. We calculated the distribution of the angles of the C–N bonds orientations, the distribution of the dihedral angle of CNOO , and the charge distribution of nitromethane molecules under various pressures, and made a comparison between low and high pressures. The effects of hydrogen bonding in high explosive materials are discussed.

scholarly journals Structure change, layer sliding, and metallization in high-pressure MoS2

2013 ◽  
Vol 87 (14) ◽  
Author(s):  
Liliana Hromadová ◽  
Roman Martoňák ◽  
Erio Tosatti
Keyword(s):  
High Pressure ◽  
Structure Change

Structure change of Mn2O3 under high pressure and pressure-induced transition

2005 ◽  
Vol 220 (11) ◽  
Author(s):  
Takamitsu Yamanaka ◽  
Takaya Nagai ◽  
Taku Okada ◽  
Tomoo Fukuda
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Diffraction Pattern ◽  
Structure Change ◽  
High Pressure Phase ◽  
Monoclinic Symmetry ◽  
Large Hysteresis ◽  
Pressure Phase

AbstractBixbyite (Mn,Fe)Pressure-induced phase transition was confirmed at about 21 GPa with a large hysteresis. The transition is reversible and non-quenchable. Powder indexing of the high-pressure phase was carried out using diffraction pattern taken at 35.06 GPa. It has a monoclinic symmetry and is not a corundum, Rh

High-pressure freezing of cells in suspension for low-voltage scanning electron microscopy (LVSEM)

1991 ◽  
Vol 49 ◽  
pp. 64-65
Author(s):  
Marek Malecki ◽  
James Pawley ◽  
Hans Ris
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Low Voltage ◽  
Culture Media ◽  
Cell Structure ◽  
Freeze Substitution ◽  
Ice Crystal ◽  
High Pressure Freezing ◽  
Cell Culture Media ◽  
Voltage Scanning

The ultrastructure of cells suspended in physiological fluids or cell culture media can only be studied if the living processes are stopped while the cells remain in suspension. Attachment of living cells to carrier surfaces to facilitate further processing for electron microscopy produces a rapid reorganization of cell structure eradicating most traces of the structures present when the cells were in suspension. The structure of cells in suspension can be immobilized by either chemical fixation or, much faster, by rapid freezing (cryo-immobilization). The fixation speed is particularly important in studies of cell surface reorganization over time. High pressure freezing provides conditions where specimens up to 500μm thick can be frozen in milliseconds without ice crystal damage. This volume is sufficient for cells to remain in suspension until frozen. However, special procedures are needed to assure that the unattached cells are not lost during subsequent processing for LVSEM or HVEM using freeze-substitution or freeze drying. We recently developed such a procedure.

Prolonged Fixation Studies For Spaceflight

1973 ◽  
Vol 31 ◽  
pp. 332-333
Author(s):  
Robert Corbett ◽  
Delbert E. Philpott ◽  
Sam Black
Keyword(s):  
High Pressure ◽  
Living Systems ◽  
Prolonged Storage ◽  
Time Intervals ◽  
Early Signs ◽  
Large Numbers

Observation of subtle or early signs of change in spaceflight induced alterations on living systems require precise methods of sampling. In-flight analysis would be preferable but constraints of time, equipment, personnel and cost dictate the necessity for prolonged storage before retrieval. Because of this, various tissues have been stored in fixatives and combinations of fixatives and observed at various time intervals. High pressure and the effect of buffer alone have also been tried.Of the various tissues embedded, muscle, cartilage and liver, liver has been the most extensively studied because it contains large numbers of organelles common to all tissues (Fig. 1).

Cryosectioning plant roots prepared by high-pressure freezing

1987 ◽  
Vol 45 ◽  
pp. 662-663
Author(s):  
R.E. Crang ◽  
M. Mueller ◽  
K. Zierold
Keyword(s):  
High Pressure ◽  
Cell Walls ◽  
Plant Tissues ◽  
Ice Crystal ◽  
High Pressure Freezing ◽  
Vitreous State ◽  
Radial Depth ◽  
Irregular Topography ◽  
Considerable Depth ◽  
Conventional Freezing

Obtaining frozen-hydrated sections of plant tissues for electron microscopy and microanalysis has been considered difficult, if not impossible, due primarily to the considerable depth of effective freezing in the tissues which would be required. The greatest depth of vitreous freezing is generally considered to be only 15-20 μm in animal specimens. Plant cells are often much larger in diameter and, if several cells are required to be intact, ice crystal damage can be expected to be so severe as to prevent successful cryoultramicrotomy. The very nature of cell walls, intercellular air spaces, irregular topography, and large vacuoles often make it impractical to use immersion, metal-mirror, or jet freezing techniques for botanical material.However, it has been proposed that high-pressure freezing (HPF) may offer an alternative to the more conventional freezing techniques, inasmuch as non-cryoprotected specimens may be frozen in a vitreous, or near-vitreous state, to a radial depth of at least 0.5 mm.

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