49 research outputs found
Preoperative Estimation and Resection of Gliomas Using Positron Emission Tomography/Computed Tomography Neuronavigation
The mechanism and kinetics of oil shale pyrolysis in the presence of water
The hydrous thermo-simulation experiments on oil shale sample from Liushuhe basin have been performed using autoclave. The mechanism and kinetics of oil shale pyrolysis were investigated. The formation mechanism of pyrolysates including retorting gas, oil and bitumen, were evaluated in the presence of saturated and unsaturated water, respectively. The results show that the physicochemical properties of water have greatly changed in high temperature and pressure. At the same time, water has three kinds of effect on the oil shale pyrolysis, including the protection of free radical, catalytic action and swelling. The pyrolysis temperature was carried out about 70 °C earlier, and the generated processing of hydrocarbon would be easier under the aqueous. The consecutive first order reaction model involving bitumen as an intermediate product was used in the data analysis in order to determine the pyrolysis kinetic parameters. It was found that the apparent activation energy of kerogen pyrolysis was lower than bitumen pyrolysis. Keywords: Oil shale, Mechanism, Free radical reaction, Carbocation reaction, Kinetics, Aqueous mediu
Study of CH4 and CO2 competitive adsorption on shale in Yibin, Sichuan Province of China
Shale gas is an unconventional gas source with substantial development potential. In this study, Longmaxi Formation shale from the Silurian system in Yibin, Sichuan Province was collected for characterizing total organic carbon (TOC), clay mineral content, and other reservoir properties. The pore structure of shale was analyzed by field-emission scanning electron microscopy and low-temperature N2 adsorption–desorption method. Isothermal adsorption experiments for CH4 and CO2 mixtures in shale samples were performed. The second Virial coefficient was used to calculate for the compressibility factor of the gas mixture. The influencing factors of gas adsorption capacity of shale were analyzed. Finally, the CH4 and CO2 adsorption capacities and selection of shale samples were investigated. Under low pressure, the total gas mixture capacity of shale samples was positively correlated with pressure. When the pressure increased to a certain extent, the growth trend of gas mixture adsorption capacity of shale samples decreased. The mixed gas adsorption volume is high at 50 °C for all the proportion. Given the same temperature and pressure, the CO2 adsorption of shale samples is higher than the CH4 adsorption. In competitive adsorption, shale prefers to adsorb CO2. Therefore, CO2 is easier to be adsorbed by shale and this causes CH4 to be released from the adsorption site. Keywords: CH4, CO2, Competitive adsorption, Second Virial coefficien
ARA67/PAT1 Functions as a Repressor To Suppress Androgen Receptor Transactivation
The androgen receptor (AR) may recruit multiple coregulators for proper or optimal transactivation. Here we report the identification and characterization of ARA67/PAT1 as an AR coregulator from a prostate cDNA library. ARA67/PAT1 was screened out as an AR N terminus interacting protein. Interaction mapping shows that the cooperation of multiple domains within ARA67/PAT1 may be required for the maximal interaction with AR. ARA67/PAT1 functions as a repressor with better suppressive effects on AR compared to glucocorticoid receptor and estrogen receptor. Further mechanism dissection reveals that the interrupted AR cytoplasmic-nuclear shuttling may play a major role in ARA67/PAT1 mediated suppression on AR. Together, these results suggest that ARA67/PAT1 may function as a novel repressor that can modulate AR function in prostate cancer
A comparative study on characteristics of sulfur and nitrogen transformation and gaseous emission for combustion of bituminous coal and char
The characteristics of sulfur and nitrogen transformation and the emissions’ comparison of sulfurous and nitrogenous gas were investigated using SEM, XPS, TG-FTIR and TG-gas analyzer during the combustion process of Shenmu bituminous coal (SM coal) and its char. SEM indicated that porosity and specific surface area of char were enlarged after coal pyrolysis and a large amount of space could be provided for the oxidation reaction of various sulfur species with oxide during the combustion process. The sulfur and nitrogen species of the two samples analyzed by XPS showed that, pyritic sulfur, organic sulfide sulfur, sulfone and sulfoxide sulfur in coal were partly transformed to thiophenic sulfur and sulfate sulfur in the pyrolysis of coal, and the total sulfur content in char was reduced. Besides, the sulfur and nitrogen species’ changes in SM coal, char and the ashes determined by XPS showed that sulfur fixation effect was enhanced in the presence of calcium oxide during combustion. The component analysis of the gas during combustion via TG-FTIR indicated that SO2 and NO2 began to escape at 300 °C and reached maximum at about 1100 °C, by contrast, the emissions of SO2 and NO2 of char were below that of SM coal throughout the whole combustion process. The wide range of TG-gas analyzer analysis revealed that the SO2 and NOx emissions of SM coal were 2.51 and 1.71 times as much as char burning, respectively. Keywords: Coal, Char, S/N, Combustion, Transformation, XPS, TG-FTI
<i>MIR390</i> Is Involved in Regulating Anthracnose Resistance in Apple
As an important cash crop in China, apple has a good flavor and is rich in nutrients. Fungal attacks have become a major obstacle in apple cultivation. Colletotrichum gloeosporioides is one of the most devastating fungal pathogens in apple. Thus, discovering resistance genes in response to C. gloeosporioides may aid in designing safer control strategies and facilitate the development of apple resistance breeding. A previous study reported that ‘Hanfu’ autotetraploid apple displayed higher C. gloeosporioides resistance than ‘Hanfu’ apple, and the expression level of mdm-MIR390b was significantly upregulated in autotetraploid plants compared to that in ‘Hanfu’ plants, as demonstrated by digital gene expression (DGE) analysis. It is still unclear, however, whether mdm-MIR390b regulates apple anthracnose resistance. Apple MIR390b was transformed into apple ‘GL-3′ plants to identify the functions of mdm-MIR390b in anthracnose resistance. C. gloeosporioides treatment analysis indicated that the overexpression of mdm-MIR390b reduced fungal damage to apple leaves and fruit. Physiology analysis showed that mdm-MIR390b increased C. gloeosporioides resistance by improving superoxide dismutase (SOD) and peroxidase (POD) activity to alleviate the damage caused by O2− and H2O2. Our results demonstrate that mdm-MIR390b can improve apple plants’ anthracnose resistance
Generalized Asymmetric Correntropy for Robust Adaptive Filtering: A Theoretical and Simulation Study
Correntropy has been proved to be effective in eliminating the adverse effects of impulsive noises in adaptive filtering. However, correntropy is not desirable when the error between the two random variables is asymmetrically distributed around zero. To address this problem, asymmetric correntropy using an asymmetric Gaussian function as the kernel function was proposed. However, an asymmetric Gaussian function is not always the best choice and can be further expanded. In this paper, we propose a robust adaptive filtering based on a more flexible definition of asymmetric correntropy, which is called generalized asymmetric correntropy that adopts a generalized asymmetric Gaussian density (GAGD) function as the kernel. With the shape parameter properly selected, the generalized asymmetric correntropy may get better performance than the original asymmetric correntropy. The steady-state performance of the adaptive filter based on the generalized maximum asymmetric correntropy criterion (GMACC) is theoretically studied and verified by simulation experiments. The asymmetric characteristics of queue delay in satellite networks is analyzed and described, and the proposed algorithm is used to predict network delay, which is essential in space telemetry. Simulation results demonstrate the desirable performance of the new algorithm
Generalized Asymmetric Correntropy for Robust Adaptive Filtering: A Theoretical and Simulation Study
Correntropy has been proved to be effective in eliminating the adverse effects of impulsive noises in adaptive filtering. However, correntropy is not desirable when the error between the two random variables is asymmetrically distributed around zero. To address this problem, asymmetric correntropy using an asymmetric Gaussian function as the kernel function was proposed. However, an asymmetric Gaussian function is not always the best choice and can be further expanded. In this paper, we propose a robust adaptive filtering based on a more flexible definition of asymmetric correntropy, which is called generalized asymmetric correntropy that adopts a generalized asymmetric Gaussian density (GAGD) function as the kernel. With the shape parameter properly selected, the generalized asymmetric correntropy may get better performance than the original asymmetric correntropy. The steady-state performance of the adaptive filter based on the generalized maximum asymmetric correntropy criterion (GMACC) is theoretically studied and verified by simulation experiments. The asymmetric characteristics of queue delay in satellite networks is analyzed and described, and the proposed algorithm is used to predict network delay, which is essential in space telemetry. Simulation results demonstrate the desirable performance of the new algorithm