Enhanced luminescence and thermal stability of (Sr,Ca)AlSiN 3 :Eu 2+ via superficial organic carbon modification

2021 ◽  
Author(s):  
Junhang Tian ◽  
Weidong Zhuang ◽  
Ronghui Liu ◽  
Yuanhong Liu ◽  
Guantong Chen ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Organic Carbon ◽  
Carbon Modification ◽  
Enhanced Luminescence ◽  
Thermal Stability Of

Enhanced thermal stability of CaAlSiN 3 :Eu 2+ phosphors by superficial carbon modification

2020 ◽  
Vol 103 (12) ◽  
pp. 6941-6950
Author(s):  
Junhang Tian ◽  
Weidong Zhuang ◽  
Ronghui Liu ◽  
Yuanhong Liu ◽  
Guantong Chen ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Carbon Modification ◽  
Thermal Stability Of

Partitioning Light Attenuation in an Acidic Lake

1985 ◽  
Vol 42 (11) ◽  
pp. 1707-1711 ◽  
Author(s):  
Steven W. Effler ◽  
Gary C. Schafran ◽  
Charles T. Driscoll
Keyword(s):  
Thermal Stability ◽  
New York ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Light Absorption ◽  
Light Attenuation ◽  
Systematic Evaluation ◽  
Acidic Lake ◽  
Hypolimnetic Heating ◽  
Thermal Stability Of

Although a number of researchers have reported that acidification of lakes is accompanied by an increase in transparency, there has been no systematic evaluation of the processes responsible for this transformation. In this study we partitioned the attenuation of light in acidic Dart's Lake, located in the Adirondack region of New York from May to September 1982. We observed that changes in light attenuation (Kd) and light absorption (a) were regulated largely by "gelbstoff." Substantial decreases in Kd and a occurred through the study period and were correlated with a depletion in the concentration of dissolved organic carbon (DOC). In-lake concentrations of DOC were controlled by terrigeneous loading and in-lake processes. The decrease in DOC and the attendant decreases in a and Kd were coupled to a loss of Al from the water column of the lake. We suggest that coagulation/adsorption of DOC by Al may have contributed to increases in lake clarity. Increased transparency is significant because it enhances hypolimnetic heating and decreases the thermal stability of lakes.

Thermal stability of organic carbon in soil aggregates as affected by soil erosion and deposition

2018 ◽  
Vol 175 ◽  
pp. 82-90 ◽  
Author(s):  
Xiaodong Nie ◽  
Zhongwu Li ◽  
Jinquan Huang ◽  
Lin Liu ◽  
Haibin Xiao ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Soil Erosion ◽  
Organic Carbon ◽  
Soil Aggregates ◽  
Erosion And Deposition ◽  
Thermal Stability Of

Age and Thermal Stability of Particulate Organic Matter Fractions Indicate the Presence of Black Carbon in Soil

Radiocarbon ◽  
2015 ◽  
Vol 57 (1) ◽  
pp. 99-107 ◽  
Author(s):  
Jens Leifeld ◽  
Maria Heiling ◽  
Irka Hajdas
Keyword(s):  
Thermal Stability ◽  
Organic Carbon ◽  
Black Carbon ◽  
The Other ◽  
Plant Residues ◽  
Microbial Decomposition ◽  
Relative Contribution ◽  
Individual Site ◽  
Heat Released ◽  
Thermal Stability Of

Black carbon (BC) from incomplete combustion of organic materials is abundant in many soils. Its age is often higher than that of thermally unaltered soil organic carbon (SOC) owing to the presence of BC from fossil sources or to a high recalcitrance against microbial decomposition compared to that of plant residues. For a meaningful application of radiocarbon as an indicator for soil carbon age and turnover, the relative contribution of BC needs to be quantified, but BC is difficult to separate physically from soil. However, BC is thermally more stable than SOC, and hence thermal stability may provide a quantitative BC indicator. Here, we analyzed 30 light particulate organic carbon (POC) soil fractions for their thermal stability and for their 14C signature. POC is particularly sensitive to “contamination” with BC, because it is obtained by combined size and density fractionation. A steady-state “bomb” 14C model was used to derive mean POC ages. Soils from four sample sets, each consisting of six to eight individual POC samples and representing different field sites and POC types, were analyzed. Samples from one of the sets were virtually BC free, and their mean POC ages ranged from 60 to 100 yr. The 14C signature of samples from the other three sets indicated the presence of very old carbon, with mean POC ages of several hundred and up to 3500 yr. Two indicators for thermal stability—(1) the amount of heat released at temperatures >450°C and (2) the amount of heat released at 500°C (the latter representing the peak temperature of heat released from charcoal isolated from soil)—correlated both significantly and nonlinearly with POC age, indicating that samples with high BC content were older than those with low BC content. It can be concluded that at an individual site with increasing abundance of BC, both the age and the thermal stability of POC increase. However, thermal stability proved to be a reliable predictor for BC in only one sample set, whereas thermal signals of the other two BC-containing sample sets were not significantly different from those of BC-free samples. Thermal stability thus gives no unequivocal indication for the presence of BC in POC across different sites.

Thermal stability of soil organic carbon after long-term manure application across land uses and tillage systems in an oxisol

CATENA ◽  
2021 ◽  
Vol 200 ◽  
pp. 105164
Author(s):  
Matheus Sampaio C. Barreto ◽  
Marlon Ramlogan ◽  
Dener Marcio S. Oliveira ◽  
Ernst Eduard J. Verburg ◽  
Evert J. Elzinga ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Land Uses ◽  
Tillage Systems ◽  
Manure Application ◽  
Thermal Stability Of

The Ordered Phase Formation in Ti-Al-Ga Alloys

1970 ◽  
Vol 28 ◽  
pp. 440-441
Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Titanium Alloys ◽  
Growth Kinetics ◽  
Stoichiometric Composition ◽  
Good Potential ◽  
Alpha Titanium ◽  
Cold Rolled ◽  
Kinetics Of ◽  
Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

Microstructure studies of tungsten silicide schottky contacts on Gaas

1987 ◽  
Vol 45 ◽  
pp. 328-329
Author(s):  
Yih-Cheng Shih ◽  
E. L. Wilkie
Keyword(s):  
Thermal Stability ◽  
Field Effect Transistors ◽  
Schottky Contact ◽  
Schottky Contacts ◽  
Excellent Thermal Stability ◽  
Barrier Heights ◽  
Gaas Substrates ◽  
Film Adhesion ◽  
Threshold Voltages ◽  
Thermal Stability Of

Tungsten silicides (WSix) have been successfully used as the gate materials in self-aligned GaAs metal-semiconductor-field- effect transistors (MESFET). Thermal stability of the WSix/GaAs Schottky contact is of major concern since the n+ implanted source/drain regions must be annealed at high temperatures (∼ 800°C). WSi0.6 was considered the best composition to achieve good device performance due to its low stress and excellent thermal stability of the WSix/GaAs interface. The film adhesion and the uniformity in barrier heights and ideality factors of the WSi0.6 films have been improved by depositing a thin layer of pure W as the first layer on GaAs prior to WSi0.6 deposition. Recently WSi0.1 has been used successfully as the gate material in 1x10 μm GaAs FET's on the GaAs substrates which were sputter-cleaned prior to deposition. These GaAs FET's exhibited uniform threshold voltages across a 51 mm wafer with good film adhesion after annealing at 800°C for 10 min.

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