scholarly journals Dielectric Relaxor and Conductivity Mechanism in Fe-Substituted PMN-32PT Ferroelectric Crystal

Crystals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 241 ◽  
Author(s):  
Xiaojuan Li ◽  
Xing Fan ◽  
Zengzhe Xi ◽  
Peng Liu ◽  
Wei Long ◽  
...  
Keyword(s):  
High Temperature ◽  
Dielectric Relaxation ◽  
Oxygen Vacancies ◽  
Conduction Mechanism ◽  
Ferroelectric Crystal ◽  
Conductivity Mechanism ◽  
Diffusion Phase ◽  
Charged Defects ◽  
The Relationship ◽  
Dielectric Relaxor

Fe-substituted PMN-32PT relaxor ferroelectric crystals were grown by a high-temperature flux method. The effects of charged defects on the dielectric relaxor and conductivity mechanism were discussed in detail. The Fe-substituted PMN-32PT crystal showed a high coercive field (Ec = 765 V/mm), due to domain wall-pinning, induced by charged defect dipoles. Three dielectric anomaly peaks were observed, and the two dielectric relaxation peaks at low temperature were associated with the diffusion phase transition, while the high temperature one resulted from the short-range hopping of oxygen vacancies. At temperature T ≤ 150 °C, the dominating conduction carriers were electrons coming from the first ionization of oxygen vacancies. For the temperature range from 200 to 500 °C, the conductivity was composed of the bulk and interface between sample and electrode, and the oxygen vacancies were suggested to be the conduction mechanism. Above 550 °C, the trapped electrons from the Ti3+ center were excited and played a major role in electrical conduction. Our results are helpful for better understanding the relationship between dielectric relaxation and the conduction mechanism.

scholarly journals The modification effect of temperature on the relationship between air pollutants and daily incidence of influenza in Ningbo, China

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Rui Zhang ◽  
Yujie Meng ◽  
Hejia Song ◽  
Ran Niu ◽  
Yu Wang ◽  
...  
Keyword(s):  
Air Pollution ◽  
High Temperature ◽  
Air Pollutants ◽  
Meteorological Data ◽  
Effect Of Temperature ◽  
Distributed Lag ◽  
Modification Effect ◽  
Incidence Risk ◽  
The Impact ◽  
The Relationship

Abstract Background Although exposure to air pollution has been linked to many health issues, few studies have quantified the modification effect of temperature on the relationship between air pollutants and daily incidence of influenza in Ningbo, China. Methods The data of daily incidence of influenza and the relevant meteorological data and air pollution data in Ningbo from 2014 to 2017 were retrieved. Low, medium and high temperature layers were stratified by the daily mean temperature with 25th and 75th percentiles. The potential modification effect of temperature on the relationship between air pollutants and daily incidence of influenza in Ningbo was investigated through analyzing the effects of air pollutants stratified by temperature stratum using distributed lag non-linear model (DLNM). Stratified analysis by sex and age were also conducted. Results Overall, a 10 μg/m3 increment of O3, PM2.5, PM10 and NO2 could increase the incidence risk of influenza with the cumulative relative risk of 1.028 (95% CI 1.007, 1.050), 1.061 (95% CI 1.004, 1.122), 1.043 (95% CI 1.003, 1.085), and 1.118 (95% CI 1.028, 1.216), respectively. Male and aged 7–17 years were more sensitive to air pollutants. Through the temperature stratification analysis, we found that temperature could modify the impacts of air pollution on daily incidence of influenza with high temperature exacerbating the impact of air pollutants. At high temperature layer, male and the groups aged 0–6 years and 18–64 years were more sensitive to air pollution. Conclusion Temperature modified the relationship between air pollution and daily incidence of influenza and high temperature would exacerbate the effects of air pollutants in Ningbo.

Influence of Enzyme Activity of Bacteria and Leucocytes in Raw Milk on Age Gelation after UHT Processing

1984 ◽  
Vol 47 (2) ◽  
pp. 105-107 ◽  
Author(s):  
BARBARA P. KEOGH ◽  
G. PETTINGILL
Keyword(s):  
Enzyme Activity ◽  
High Temperature ◽  
Inhibitory Action ◽  
Raw Milk ◽  
Bacterial Counts ◽  
High Temperature Processing ◽  
The Relationship ◽  
Ultra High Temperature

An investigation was undertaken into the relationship between the enzyme activity of cells harvested from raw milk and time taken for age gelation (TAG) to occur in the milk after ultra-high-temperature processing. It was shown that there was no relationship between the TAG and the bacterial counts on milk agar at 30°C or 7°C nor was there a relationship between the counts and the level of enzyme activity of the harvested cells. There was, however, a significant correlation between the level of enzyme activity of the harvested cells and the TAG. When extra bovine leucocytes were added to raw milk before processing, the TAG was increased. This suggested that there was an inhibitory action of leucocytes in development of age gelation.

scholarly journals Study of charge transfer mechanism and dielectric relaxation of all-inorganic perovskite CsSnCl3

RSC Advances ◽  
2021 ◽  
Vol 11 (35) ◽  
pp. 21767-21780
Author(s):  
Mohamed Ben Bechir ◽  
Mohamed Houcine Dhaou
Keyword(s):  
Charge Transfer ◽  
Dielectric Relaxation ◽  
Monoclinic Phase ◽  
Conduction Mechanism ◽  
Small Polaron ◽  
Cubic Phase ◽  
Inorganic Perovskite ◽  
Charge Transfer Mechanism ◽  
Large Polaron ◽  
Olpt Model

The conduction mechanism in CsSnCl3 is interpreted through the following two approaches: the non-overlapping small polaron tunneling (NSPT) model (monoclinic phase) and the overlapping large polaron tunneling (OLPT) model (cubic phase).

Influence of powder characteristics on the properties of green compacts of Bi-2212 powders

1997 ◽  
Vol 12 (1) ◽  
pp. 21-27 ◽  
Author(s):  
D.-W. Yuan ◽  
M. D. Aesoph ◽  
J. Kajuch
Keyword(s):  
High Temperature ◽  
Confining Pressure ◽  
Plastic Behavior ◽  
Particle Sizes ◽  
Green Density ◽  
High Temperature Superconducting ◽  
Powder Characteristics ◽  
The Relationship ◽  
Powder In Tube ◽  
Superconducting Applications

With the growing potential for use of Bi-2212 powders in high temperature superconducting applications, it is important to understand the processing characteristics of the material. To meet this need, the present work established the relationship between confining pressure and green density for powders of different particle sizes and morphologies. Mechanical properties, including elastic and plastic behavior, of the resulting green compacts were also measured as a function of relative density. Particle size and size distribution are shown to have a significant impact on the properties of interest. The implications of such findings are discussed with respect to the powder-in-tube process for making high temperature superconducting wire and tape.

High temperature impedance properties and conduction mechanism of W6+-doped CaBi4Ti4O15 Aurivillius piezoceramics

2018 ◽  
Vol 124 (20) ◽  
pp. 204101 ◽  
Author(s):  
Xinchun Xie ◽  
Zhiyong Zhou ◽  
Tianzi Wang ◽  
Ruihong Liang ◽  
Xianlin Dong
Keyword(s):  
High Temperature ◽  
Conduction Mechanism

Oxygen defect related high temperature dielectric relaxation behavior in (Ba,La)(Zr,Sn,Ti)O3 ceramics

2021 ◽  
Vol 127 (10) ◽  
Author(s):  
Ke Meng ◽  
Wenhua Li ◽  
Xingui Tang ◽  
Xiaobin Guo ◽  
Qiuxiang Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Dielectric Relaxation ◽  
Relaxation Behavior ◽  
Oxygen Defect ◽  
Dielectric Relaxation Behavior
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