In Situ Observation of Ice Formation from Water Vapor by Environmental SEM

2018 ◽  
Vol 18 (11) ◽  
pp. 6602-6608 ◽  
Author(s):  
Zhouyang Zhang ◽  
Linfeng Fei ◽  
Zhenggang Rao ◽  
Dingjun Liu ◽  
C. W. Leung ◽  
...  
2013 ◽  
Vol 19 (S2) ◽  
pp. 1724-1725
Author(s):  
L. Zhang ◽  
B.K. Miller ◽  
C. Peter

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.


Nano Letters ◽  
2013 ◽  
Vol 13 (2) ◽  
pp. 679-684 ◽  
Author(s):  
Liuxian Zhang ◽  
Benjamin K. Miller ◽  
Peter A. Crozier

2021 ◽  
Vol 13 (18) ◽  
pp. 3661
Author(s):  
Zhongbo Su ◽  
Yaoming Ma ◽  
Xuelong Chen ◽  
Xiaohua Dong ◽  
Junping Du ◽  
...  

A better understanding of the water and energy cycles at climate scale in the Third Pole Environment is essential for assessing and understanding the causes of changes in the cryosphere and hydrosphere in relation to changes of plateau atmosphere in the Asian monsoon system and for predicting the possible changes in water resources in South and East Asia. This paper reports the following results: (1) A platform of in situ observation stations is briefly described for quantifying the interactions in hydrosphere-pedosphere-atmosphere-cryosphere-biosphere over the Tibetan Plateau. (2) A multiyear in situ L-Band microwave radiometry of land surface processes is used to develop a new microwave radiative transfer modeling system. This new system improves the modeling of brightness temperature in both horizontal and vertical polarization. (3) A multiyear (2001–2018) monthly terrestrial actual evapotranspiration and its spatial distribution on the Tibetan Plateau is generated using the surface energy balance system (SEBS) forced by a combination of meteorological and satellite data. (4) A comparison of four large scale soil moisture products to in situ measurements is presented. (5) The trajectory of water vapor transport in the canyon area of Southeast Tibet in different seasons is analyzed, and (6) the vertical water vapor exchange between the upper troposphere and the lower stratosphere in different seasons is presented.


Author(s):  
L. A. Touryan ◽  
L. W. Hobbs

Electron microscopy has greatly aided in understanding the microstructure and morphological development of corrosion scales formed by high temperature oxidation and sulfidation of metals. However, this knowledge has been limited by the fact that the microstructure and morphological features could only be studied after corrosion had occurred. The recent development of the environmental scanning electron microscope (ESEM) permits actual in-situ observation of the evolution of high temperature corrosion scales at the scale-gas interface, allowing for a better understanding of the detailed mechanisms of scale growth. The objective of this study is to investigate the evolution of oxidation and sulfidation scales on various metals and alloys.R.A. Rapp and associates adapted a conventional SEM for oxidation studies by developing a stage that could be heated in excess of 1000 C. Because of the vacuum restrictions of the SEM, a gas pipe directed at the surface of the samples was utilized in order to increase the local oxygen partial pressure, and this resulted in low (0.2 Torr) but sufficient pressures for oxidation.


Author(s):  
R. T. K. Baker ◽  
R. D. Sherwood

The catalytic gasification of carbon at high temperature by microscopic size metal particles is of fundamental importance to removal of coke deposits and conversion of refractory hydrocarbons into fuels and chemicals. The reaction of metal/carbon/gas systems can be observed by controlled atmosphere electron microscopy (CAEM) in an 100 KV conventional transmission microscope. In the JEOL gas reaction stage model AGl (Fig. 1) the specimen is positioned over a hole, 200μm diameter, in a platinum heater strip, and is interposed between two apertures, 75μm diameter. The control gas flows across the specimen and exits through these apertures into the specimen chamber. The gas is further confined by two apertures, one in the condenser and one in the objective lens pole pieces, and removed by an auxiliary vacuum pump. The reaction zone is <1 mm thick and is maintained at gas pressure up to 400 Torr and temperature up to 1300<C as measured by a Pt-Pt/Rh 13% thermocouple. Reaction events are observed and recorded on videotape by using a Philips phosphor-television camera located below a hole in the center of the viewing screen. The overall resolution is greater than 2.5 nm.


Author(s):  
R-R. Lee

Partially-stabilized ZrO2 (PSZ) ceramics have considerable potential for advanced structural applications because of their high strength and toughness. These properties derive from small tetragonal ZrO2 (t-ZrO2) precipitates in a cubic (c) ZrO2 matrix, which transform martensitically to monoclinic (m) symmetry under applied stresses. The kinetics of the martensitic transformation is believed to be nucleation controlled and the nucleation is always stress induced. In situ observation of the martensitic transformation using transmission electron microscopy provides considerable information about the nucleation and growth aspects of the transformation.


Author(s):  
S. Hagège ◽  
U. Dahmen ◽  
E. Johnson ◽  
A. Johansen ◽  
V.S. Tuboltsev

Small particles of a low-melting phase embedded in a solid matrix with a higher melting point offer the possibility of studying the mechanisms of melting and solidification directly by in-situ observation in a transmission electron microscope. Previous studies of Pb, Cd and other low-melting inclusions embedded in an Al matrix have shown well-defined orientation relationships, strongly faceted shapes, and an unusual size-dependent superheating before melting.[e.g. 1,2].In the present study we have examined the shapes and thermal behavior of eutectic Pb-Cd inclusions in Al. Pb and Cd form a simple eutectic system with each other, but both elements are insoluble in solid Al. Ternary alloys of Al (Pb,Cd) were prepared from high purity elements by melt spinning or by sequential ion implantation of the two alloying additions to achieve a total alloying addition of up to lat%. TEM observations were made using a heating stage in a 200kV electron microscope equipped with a video system for recording dynamic behavior.


Author(s):  
K. Fukushima ◽  
N. Kohyama ◽  
A. Fukami

A film-sealed high resolution environmental cell(E.C) for observing hydrated materials had been developed by us(l). Main specification of the E.C. is as follows: 1) Accelerated voltage; 100 kV. 2) Gas in the E.C.; saturated water vapour with carrier gas of 50 Torr. 3) Thickness of gas layer; 50 μm. 4) Sealing film; evaporated carbon film(20 nm thick) with plastic microgrid. 5) Resolving power; 1 nm. 6) Transmittance of electron beam; 60% at 100 kV. The E.C. had been successfully applied to the study of hydrated halloysite(2) (3). Kaolin minerals have no interlayer water and are basically non-expandable but form intercalation compounds with some specific chemicals such as hydrazine, formamide and etc. Because of these compounds being mostly changed in vacuum, we tried to reveal the structure changes between in wet air and in vacuum of kaolin minerals intercalated with hydrazine and of hydrated state of montmori1lonite using the E.C. developed by us.


2013 ◽  
Vol 133 (12) ◽  
pp. 350-357
Author(s):  
Yuta Nakashima ◽  
Ryo Monji ◽  
Katsuya Sato ◽  
Kazuyuki Minami

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