Research on Simulation Methods of Electric Field Intensity on Surface of 10 kV Cable Joint

The electric field intensity (EFI) is important characteristic quantity for evaluating the internal insulation state of cable joints. Based on finite element method, this paper proposes two EFI research methods, field-circuit coupling method and equivalent circuit method. The average EFI of the inner surface of the outer semi-conducting shield can be calculated from the current in the measuring circuit. The relative error between these two methods is about 15%, which roughly proves the consistency of the two methods. Further practical application research enables online monitoring of cable joints.

Gene expression of granulosa and cumulus cells: The prospect inpredicting the quality and developmental competence of oocytesin vitro maturation

In vitro maturation(IVM),a promising assisted reproductive technology(ART),has been evolving in clinical trials and applications.There is a huge potential demand for IVM in clinical practice because it reduces the stimulation of gonadotropins to patients and provides evidence for the safety of neonatal birth.Unfortunately,the maturation rate of oocytes in vitro is not as high as it is in vivo due to a different microenvironment.Moreover,there are still controversies in predicting the developmental capability of oocytes in IVM.The granulosa cells(GCs)and cumulus cells(CCs),closely surrounding the oocytes,play a critical role in oocytes development,while some studies have shown that they can reflect the quality of oocytes.Many studies have been conducted in terms of oocyte quality in transcriptional level in GCs and CCs of mice,Xenopus africanus,and Homo sapiens,which provides important enlightenment for the successful clinical application of IVM.However,no comprehensive reviews about how gene expression profiles affect oocytes quality have been reported.This review aimed to elucidate the gene expression profiles of GCs and CCs that have effects on the quality and developmental competence of oocytes maturation in vitro.And we also put forward a possible idea for ART in the future,integrating all gene expression profiles of GCs and CCs and predicting the quality of the oocytes.

Mesenchymal stem cells:As a multi-target cell therapy for clearingβ-amyloid deposition in Alzheimer’s disease

Extracellularβ-amyloid(Aβ)plaques and neurofibrillary tangles(NFTs)are the pathological hallmarks of Alzheimer’s disease(AD).Studies have shown that aggregates of extracellular Aβcan induce neuroinflammation mediated neurotoxic signaling through microglial activation and release of pro-inflammatory factors.Thus,modulation of Aβmight be a potential therapeutic strategy for modifying disease progression.Recently,a large number of reports have confirmed the beneficial effects of mesenchymal stem cells(MSCs)on AD.It is believed to reduce neuroinflammation,reduce Aβamyloid deposits and NFTs,increase acetylcholine levels,promote neurogenesis,reduce neuronal damage,and improve working memory and cognition.In this review,we focus on the role of MSCs in clearing Aβdeposition.MSCs have the potential to modulate Aβ-related microenvironments via enhancement of autophagy,proteolysis of Aβaggregates,phagocytic clearance of Aβby microglial M2 polarization,decrease oxidative stress(OS),and correction of abnormal sphingolipid(SL)metabolism.With advantages in clinical applications,these data suggest that the use of MSCs as a multi-target modulator of Aβwould be an effective therapeutic approach in AD.

Nonlinear Switching Transient Field Simulation of Cable Joint without Residual Charge

The analysis of the impulse voltage on the internal electric field of the cable joint plays a key role in studying the breakdown of the joint. Based on the finite element method, a three-dimensional electromagnetic field simulation model of the cable joint is established in this paper. Simulation results show that the voltage at the head of the cable joint reaches about twice the impulse voltage. The increase of the conductivity of semi-conductive material also leads to the increase of electric field intensity. Then, several points and curves at different positions are selected for further analysis in this paper. Among them, the electric field distortion at the edge of the high voltage shield is the most serious and the electric field in the air gap is the least.

Comparative study of raw and HNO_(3)-modified porous carbon from waste printed circuit boards for sulfadiazine adsorption: Experiment and DFT study

A huge amount of waste printed circuit boards(WPCBs) was produced while the electronic manufacturing industry developed rapidly. WPCBs mainly consist of organic compounds, which makes it possible to prepare them into porous carbon as valuable adsorbent. However, WPCBs are also rich in valuable metals.Cu makes up the most of these metals. It is worth studying whether the residual metal will affect the application of carbon materials. In this study, the porous active carbon(AC) was prepared from WPCBs as an adsorbent. Sulfadiazine(SD), a widely detected antibiotic contaminant, was used as a target pollutant.Nitric acid(HNO_(3)) was used to modify AC(AC-HNO_(3)) to remove the residual Cu. The experiment results showed that the adsorption kinetics of SD by AC(k = 0.0025) and AC-HNO_(3)(k = 0.0029) can be described better using a pseudo-second-order kinetic equation. The adsorption isotherms of AC and AC-HNO_(3) on SD could be fitted by the Langmuir model. AC had a larger adsorption capacity than AC-HNO_(3). Density functional theory(DFT) calculation results suggested that the-OH group and Cu on the surface of AC could be the adsorption sites and promote the SD adsorption. This work provides practical methods to recycle WPCBs into wealth and realized waste control by waste.