Structural characteristics of Abies mariesii saplings in a snowy subalpine parkland in central Japan

2007 ◽  
Vol 27 (1) ◽  
pp. 141-148 ◽  
Author(s):  
A. Mori ◽  
S. F. Hasegawa
Keyword(s):  
Structural Characteristics ◽  
Central Japan ◽  
Abies Mariesii

Coexistence of Abies mariesii and Abies veitchii in a subalpine fir-wave forest

2007 ◽  
Vol 37 (11) ◽  
pp. 2142-2152 ◽  
Author(s):  
Shin Ugawa ◽  
Kojiro Iwamoto ◽  
Kenji Fukuda
Keyword(s):  
Shade Tolerance ◽  
Height Growth ◽  
Stand Development ◽  
Central Japan ◽  
Subalpine Fir ◽  
Abies Veitchii ◽  
Abies Mariesii ◽  
Seedling Bank ◽  
Mature Stand ◽  
Sapling Bank

To clarify the mechanisms underlying the coexistence of Abies mariesii Masters and Abies veitchii Lindl. in a fir-wave forest, we surveyed the population dynamics of the two Abies species throughout stand development on Mount Shimagare, central Japan. We established three belt transects and found that, overall, A. veitchii dominated this fir-wave forest. However, A. mariesii dominated the canopy initially, whereas A. veitchii increased as stand development progressed; thus, dominant A. mariesii was eventually replaced by A. veitchii. This replacement was explained by the presence of an A. mariesii sapling bank that formed under the canopy of a mature stand and by the large A. veitchii seedling bank resulting from greater seed production. For ordinary canopy individuals, which are taller than midcanopy individuals, the increase in height suggested that taller individuals grow faster vertically regardless of species; moreover, height growth did not differ significantly between the two Abies species, which facilitated the growth of A. mariesii into the canopy and the production of seeds for the next generation. We concluded that the persistence of A. mariesii in this fir-wave forest is supported by its shade tolerance.

Effects of high light and low temperature during harsh winter on needle photodamage of Abies mariesii growing at the forest limit on Mt. Norikura in Central Japan

Plant Science ◽  
2003 ◽  
Vol 165 (1) ◽  
pp. 257-264 ◽  
Author(s):  
Jun-ya Yamazaki ◽  
Aiko Ohashi ◽  
Yuko Hashimoto ◽  
Eriko Negishi ◽  
Soji Kumagai ◽  
...  
Keyword(s):  
Low Temperature ◽  
High Light ◽  
Central Japan ◽  
Abies Mariesii ◽  
Forest Limit

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

SEM analysis of the change in the reaction rates with deposit structures in the copper-iron cementation system

1978 ◽  
Vol 36 (1) ◽  
pp. 456-457
Author(s):  
V. Annamalai ◽  
L.E. Murr
Keyword(s):  
Structural Characteristics ◽  
Secondary Electron Emission ◽  
Copper Deposit ◽  
Reaction Rates ◽  
Sem Analysis ◽  
Experimental Conditions ◽  
Major Drawback ◽  
Emission Mode ◽  
Scrap Iron ◽  
Image Position

Economical recovery of copper metal from leach liquors has been carried out by the simple process of cementing copper onto a suitable substrate metal, such as scrap-iron, since the 16th century. The process has, however, a major drawback of consuming more iron than stoichiometrically needed by the reaction.Therefore, many research groups started looking into the process more closely. Though it is accepted that the structural characteristics of the resultant copper deposit cause changes in reaction rates for various experimental conditions, not many systems have been systematically investigated. This paper examines the deposit structures and the kinetic data, and explains the correlations between them.A simple cementation cell along with rotating discs of pure iron (99.9%) were employed in this study to obtain the kinetic results The resultant copper deposits were studied in a Hitachi Perkin-Elmer HHS-2R scanning electron microscope operated at 25kV in the secondary electron emission mode.

Use of 2½ D imaging in analysis of NiTi martensite

1978 ◽  
Vol 36 (1) ◽  
pp. 610-611
Author(s):  
G. M. Michal
Keyword(s):  
Memory Effect ◽  
Monoclinic Phase ◽  
Reaction Path ◽  
Structural Characteristics ◽  
Salient Feature ◽  
Martensite Phase ◽  
Orientation Relationships ◽  
Low Symmetry ◽  
Hydride Phases ◽  
Unusual Shape

Several TEM investigations have attempted to correlate the structural characteristics to the unusual shape memory effect in NiTi, the consensus being the essence of the memory effect is ostensible manifest in the structure of NiTi transforming martensitic- ally from a B2 ordered lattice to a low temperature monoclinic phase. Commensurate with the low symmetry of the martensite phase, many variants may form from the B2 lattice explaining the very complex transformed microstructure. The microstructure may also be complicated by the enhanced formation of oxide or hydride phases and precipitation of intermetallic compounds by electron beam exposure. Variants are typically found in selfaccommodation groups with members of a group internally twinned and the twins themselves are often observed to be internally twinned. Often the most salient feature of a group of variants is their close clustering around a given orientation. Analysis of such orientation relationships may be a key to determining the nature of the reaction path that gives the transformation its apparently perfect reversibility.

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