Effect of direct current electric field intensity and electrolyte layer thickness on oxygen reduction in simulated atmospheric environment

The effect of direct current (DC) electric field and electrolyte layer thickness on oxygen reduction in simulated atmospheric environment were investigated using electrochemical measurements. The results show that the limiting diffusion current density (ilim) decreases with increasing the thin electrolyte layers (TELs) thickness but it increases with increasing the DC electric field intensity. The potential shifts negatively with the DC electric field. It is found that the DC electric field enables OH− ions to quickly migrate from the solution/electrode interface to the electrolyte layer. All these features promote the cathodic reduction process thereby enhancing the metal corrosion rate

Influence of androgen receptor in vascular cells on reperfusion following hindlimb ischaemia

AIMS:Studies in global androgen receptor knockout (G-ARKO) and orchidectomised mice suggest that androgen accelerates reperfusion of the ischaemic hindlimb by stimulating angiogenesis. This investigation used novel, vascular cell-specific ARKO mice to address the hypothesis that the impaired hindlimb reperfusion in G-ARKO mice was due to loss of AR from cells in the vascular wall. METHODS AND RESULTS:Mice with selective deletion of AR (ARKO) from vascular smooth muscle cells (SM-ARKO), endothelial cells (VE-ARKO), or both (SM/VE-ARKO) were compared with wild type (WT) controls. Hindlimb ischaemia was induced in these mice by ligation and removal of the femoral artery. Post-operative reperfusion was reduced in SM-ARKO and SM/VE-ARKO mice. Immunohistochemistry indicated that this was accompanied by a reduced density of smooth muscle actin-positive vessels but no change in the density of isolectin B4-positive vessels in the gastrocnemius muscle. Deletion of AR from the endothelium (VE-ARKO) did not alter post-operative reperfusion or vessel density. In an ex vivo (aortic ring culture) model of angiogenesis, AR was not detected in vascular outgrowths and angiogenesis was not altered by vascular ARKO or by exposure to dihydrotestosterone (DHT 10(-10)-10(-7)M; 6 days). CONCLUSION:These results suggest that loss of AR from vascular smooth muscle, but not from the endothelium, contributes to impaired reperfusion in the ischaemic hindlimb of G-ARKO. Impaired reperfusion was associated with reduced collateral formation rather than reduced angiogenesis

Research and Implementation of Optimization and Promotion of Power Grid Emergency Command Center

In order to enable the power grid emergency command center to meet the needs of the emergency work under the current new situation, and provide strong support for emergency response and important activities of power conservation, based on the in-depth study and analysis of the application scenarios and basic business of the power grid emergency command center, combined with advanced information communication technology, and studied the optimization and upgrading methods of the power grid emergency command center. Through the research on the optimization and upgrading method of power grid emergency command center, the optimization and upgrading scheme is proposed to guide the power grid enterprises to carry out the optimization and upgrading work of emergency command center. The optimization and upgrading scheme of the power grid emergency command center will be used for the transformation and upgrading of the emergency command center of the power grid companies at all levels, which will help the power grid companies at all levels to improve their emergency

Safety Assessment of Heavy Metal in Tea Garden Soil: A Case Study of Specialized Tea Towns in Guangdong

More than 20 soil samples were collected from tea gardens of specialized tea towns in Guangdong, including Fenglang Town and Fengshun Town in Meizhou City, Changshan Town in Lianjiang City, Fenghuang Town in Chaozhou City. Content of 6 types of heavy metal (Cr, Cu, Pb, As, Cd, Hg) in tea garden soil was measured. On the basis of these, the safety was assessed. Results show that the comprehensive pollution index of these 6 types of heavy metal is lower than 0.7. According to Soil Pollution Grading Standard formulated by China Green Food Development Center, the soil is not polluted by heavy metal and remains at safety level. It proves that overall soil condition of specialized tea gardens in Guangdong Province is not polluted by heavy metal

Degradation and corresponding failure mechanism for GaN-based LEDs

The degradation behaviors of high power GaN-based vertical blue LEDs on Si substrates were measured using in-situ accelerated life test. The results show that the dominant failure mechanism would be different during the operation. Besides that, the corresponding associated failure mechanisms were investigated systematically by using different analysis technologies, such as Scan Electron Microscopy, Reflectivity spectroscopy, Transient Thermal Analysis, Raman Spectra, etc. It is shown that initially, the failure modes were mainly originated from the semiconductor die and interconnect, while afterwards, the following serious deterioration of the radiant fluxes was attributed to the package. The interface material and quality, such as die attach and frame, play an important role in determining the thermal performance and reliability. In addition, the heating effect during the operation will also release the compressive strain in the chip. These findings will help to improve the reliability of GaN-based LEDs, especially for the LEDs with vertical structure