112 research outputs found
The Characteristics of Mechanical Grinding on Kaolinite Structure and Thermal Behavior
AbstractThe relationship between kaolinite structure and the temperature of thermal transformation of phase was discussed in this paper through grinding and heating treatment. The results show that the structure of kaolinite is destroyed rapidly with increasing mechanical grinding time, and the kaolinite structure collapses completely after 1h grinding. The temperature of thermal transformation of phase decreases with the destruction of kaolinite structure. This result has a great significance for the utilization of kaolinite associated with coal measures in China
Dividend policy and earnings management across countries
This paper examines whether dividend policy is associated with earnings management and whether the relationship varies across countries with wide-ranging degrees of institutional strength and transparency. Based on a sample of 23,429 corporations from 29 countries, we show that dividend payers manage earnings less than dividend non-payers, and that this evidence is stronger in countries with weak investor protection and high opacity. Further, we find that dividend payers manage earnings less when they issue equity following dividend payments, and that this result is more pronounced in countries with weak institutions and low transparency. Overall, our evidence suggests that firms may employ dividend policies associated with less earnings manipulation to mitigate agency concerns and to establish credible reputation, thereby facilitating access to external funds
PET Tracer Conversion among Brain PET via Variable Augmented Invertible Network
Positron emission tomography (PET) serves as an essential tool for diagnosis
of encephalopathy and brain science research. However, it suffers from the
limited choice of tracers. Nowadays, with the wide application of PET imaging
in neuropsychiatric treatment, 6-18F-fluoro-3, 4-dihydroxy-L-phenylalanine
(DOPA) has been found to be more effective than 18F-labeled
fluorine-2-deoxyglucose (FDG) in the field. Nevertheless, due to the complexity
of its preparation and other limitations, DOPA is far less widely used than
FDG. To address this issue, a tracer conversion invertible neural network
(TC-INN) for image projection is developed to map FDG images to DOPA images
through deep learning. More diagnostic information is obtained by generating
PET images from FDG to DOPA. Specifically, the proposed TC-INN consists of two
separate phases, one for training traceable data, the other for rebuilding new
data. The reference DOPA PET image is used as a learning target for the
corresponding network during the training process of tracer conversion.
Meanwhile, the invertible network iteratively estimates the resultant DOPA PET
data and compares it to the reference DOPA PET data. Notably, the reversible
model employs variable enhancement technique to achieve better power
generation. Moreover, image registration needs to be performed before training
due to the angular deviation of the acquired FDG and DOPA data information.
Experimental results exhibited excellent generation capability in mapping
between FDG and DOPA, suggesting that PET tracer conversion has great potential
in the case of limited tracer applications
Taxifolin increased semen quality of Duroc boars by improving gut microbes and blood metabolites.
peer reviewedTaxifolin (TAX), as a natural flavonoid, has been widely focused on due to its strong anti-oxidation, anti-inflammation, anti-virus, and even anti-tumor activity. However, the effect of TAX on semen quality was unknown. The purpose of this study was to analyze the beneficial influences of adding feed additive TAX to boar semen in terms of its quality and potential mechanisms. We discovered that TAX increased sperm motility significantly in Duroc boars by the elevation of the protein levels such as ZAG, PKA, CatSper, and p-ERK for sperm quality. TAX increased the blood concentration of testosterone derivatives, antioxidants such as melatonin and betaine, unsaturated fatty acids such as DHA, and beneficial amino acids such as proline. Conversely, TAX decreased 10 different kinds of bile acids in the plasma. Moreover, TAX increased "beneficial" microbes such as Intestinimonas, Coprococcus, Butyrivibrio, and Clostridium_XlVa at the Genus level. However, TAX reduced the "harmful" intestinal bacteria such as Prevotella, Howardella, Mogibacterium, and Enterococcus. There was a very close correlation between fecal microbes, plasma metabolites, and semen parameters by the spearman correlation analysis. Therefore, the data suggest that TAX increases the semen quality of Duroc boars by benefiting the gut microbes and blood metabolites. It is supposed that TAX could be used as a kind of feed additive to increase the semen quality of boars to enhance production performance
A Review of Current Methodologies for Regional Evapotranspiration Estimation from Remotely Sensed Data
An overview of the commonly applied evapotranspiration (ET) models using remotely sensed data is given to provide insight into the estimation of ET on a regional scale from satellite data. Generally, these models vary greatly in inputs, main assumptions and accuracy of results, etc. Besides the generally used remotely sensed multi-spectral data from visible to thermal infrared bands, most remotely sensed ET models, from simplified equations models to the more complex physically based two-source energy balance models, must rely to a certain degree on ground-based auxiliary measurements in order to derive the turbulent heat fluxes on a regional scale. We discuss the main inputs, assumptions, theories, advantages and drawbacks of each model. Moreover, approaches to the extrapolation of instantaneous ET to the daily values are also briefly presented. In the final part, both associated problems and future trends regarding these remotely sensed ET models were analyzed to objectively show the limitations and promising aspects of the estimation of regional ET based on remotely sensed data and ground-based measurements
Essay on international financial markets
163 p.This dissertation consists of three essays. The first essay explores the underlying economic forces that drive the variation in risk premia around the world. It examines whether and how differences in the investors' information environment affect cross-country differences in the volatility of equity risk premia. We use the variance-decomposition approach and implied cost of capital method to estimate time variation in risk premia for 40 developed and developing countries worldwide. Consistent with theoretical predictions, countries with better information environments tend to experience a lower risk premium volatility, even after controlling for various country variables that are previously found to be good predictors of risk premia. Our further analysis of an exogenous event, specifically the 1997 Asian financial crisis, corroborates our finding that a country's information environment plays an important role in explaining the volatility of its market risk premium.DOCTOR OF PHILOSOPHY (NBS
- …