Correlation between geometrical parameters of electrical tree and corresponding partial discharge parameters in XLPE

This paper deals with the experimental study on the correlation between the geometrical parameters of electrical tree and corresponding partial discharge (PD) characteristic parameters in the course of electrical tree aging within cross linked polyethylene (XLPE) insulation. The electrical tree aging tests were performed on specimens removed from a section of 220 kV transmission cable. The PD macroscopic characteristic parameters were found to be significantly dependent on the corresponding geometrical parameters of electrical tree channels in the course of aging of XLPE, and different kind of electrical tree has different characteristics, and there is obvious correlation between the type of electrical tree and the pre-applied power-frequency stress. Beside, using regression analysis, the expression of the relation between them were obtained, and from which it can be seen that there is significant nonlinear correlation between geometrical parameters of electrical tree and corresponding PD characteristic parameters in the course of aging of XLPE. Therefore, the aging degree of XLPE can be effectively evaluated by recognizing the changing regularity of the PD rnacroscopic characteristic parameters.     

Influence of polymer addition on performance and mechanical properties of lightweight aggregate concrete

The influence of polymer addition on microstructure, performance and mechanical properties of lightweight aggregate concrete was investigated. It was found that the addition of polymer improved the performance and mechanical properties of lightweight aggregate concrete. It was ascertained that the modification of microstructural uniformity and densification with the addition of polymer is responsible for the enhancement of mechanical properties.With respect to compressive strength and bending strength, the lightweight aggregate concrete added with 13% ethylene-acetate ethylene interpolymer ( EVA ) exhibits preferred mechanical properties.     

Spectrofluorimetric method for the determination of triamcinolone acetonide

0　IntroductionTriamcinoloneAcetonide,9 fluoro 11β,2 1 dihydroxy 16α,17[(1 methylethylidene)bis (oxy) ] pregn 1,4 diene 3,2 0 dione,Mris 4 34.4 8(abr.TA ) .Itbelongstoaclassofadrenalcortexhormonedrug ,whosefunctionsareaffectionofsugarmetabolism ,anti inflammationandresistancehypersusceptibilityetc.TAcanbesuitabletorheumatoidarthritisanddermatosissuchashypersusceptibilityandneuropathicdermatitis .ThefunctionsofTAisstrongerandlongerthantriamcinolone[1 ,2 ] .ThecommonmethodsofdetectingTAm…     

Activation of proteinkinase ERK mediates induction of macrophage MMP-12 by OxLDL

The present study was undertaken to investigate the effect of oxidized low density lipoprotein (oxLDL) on the expression of maerophage matrix metalloproteinase-12 (MMP-12), and the possible mechanisms. Activation of extracellular signal-regulated kinase 1/2 (ERK1/2) was detected by Western blot analysis.Enzymatic activity of MMP-12 was determined by β-casein zymography. RT-PCR analysis was used to measure the mRNA expression level of MMP-12. OxLDL-stimulated macrophages produced increased casein-degrading activities and oxLDL also significantly increased the mRNA level of MMP-12 in a dose-dependent manner.OxLDL stimulated the phosphorylation of ERK1/2 in macrophages. The use of the specific inhibitor indicated that the ERK1/2 signaling pathway was required for the induction of MMP-12.These data demonstrated that oxLDL induced MMP-12 expression in macrophages through an ERK1/2-dependent pathway.     

Study on screening and cultivation conditions of xylanase-producing alkalophilic bacterial

Xylanisthemajorcomponentofplantcellwallsandthemostabundantpentosaninnature.Xylancontainsβ 1,4 linkedd xylosebackboneswitharabinose,4 O methyl d glucuronicacid,andaceticacidsubstituents[1 ] .Thexylan degradingen zymesincludeendoxylanase(1,4 β d xylanxylanohydrolase;EC3.2 .1.8)and β xylosidase (1,4 β d xylanxylanohydrolase;EC 3.2 .1.37) .xylanasedegradesthexylanbackboneintoxylo bioseandxylooligosaccharides,whileβ xylosidasereleasesxylosylresiduesfromthenonreducingendsofxylooligosaccha…     

The symmetric solutions of affiliated value model

0　IntroductionIntheprocessofR&Ditem ,thereisusuallycompetition .ManyfirmswanttoinvestR&Dtoobtainapatent.Lury[1 ] gaveanequilibriuminvestmentundertheconditionofone timeinvestmentandcontinuousinvestmentwhenthepayoffwasafixedprize.Ref.[2 ]analyzedtheeffectofinformationsharinginR&D .TherearemanyliteraturesaboutanalysisofR&DlevelswhenfirmscompeteinoutputmarketafterR&Dsucceeds[3 ,4] .Additionally ,todecideinvestmentlevel,therearemanyliteraturesaboutR&Ditem’spricing .MondherBellalah[5] ,K .…     

Respective roles of short-and long-range interactions in protein folding

A new method was presented to discuss the respective roles of short- and long-range interactions in protein folding. It‘s based on an off-lattice model, which is also being called as toy model. Simulated annealing algorithm was used to search its native conformation. When it is applied to analysis proteins lagt and laho, we find that helical segment catmot fold into native conformation without the influence of long-range interactions. That‘s to say that long-range interactions are the main determinants in protein folding.     

Synthesis and crystal structure of tetranuclear zinc benzoate

A tetranuclear zinc benzoate Zr4O(C6H5CO2)6 was synthesized and characterized by X-ray single crystal determination. It crystallizes in cubic, space group Ia-3d. Its crystal cell is very large, α=4.10063(18)nm, V=68.953(5)nm^3 and Z=48. The structure is composed of discrete Zr4O(C6H5CO2)6 molecules. In each molecule, four zinc atoms are held together by a central oxygen atom, which results in the formation of a regular tetrahedron. All benzoate ligands coordinate to zinc atoms in a bidentate bridging mode. Each zinc atom is in a slightly distorted tetrahedral geometry, coordinated by three benzoate oxygen atoms and the central oxygen atom. The intermolecular interactions result in the formation of a three-dimensional supramolecular framework, with non-intersecting parallel channels.     

An improved spatially aware routing algorithm for mobile ad hoc network in inter-vehicle communication

A new algorithm called spatially aware routing algorithm with enhanced learning (SAREL) is proposed to guarantee the rationality of route selecting in inter-vehicle communication scenario. Firstly, the traffic model is discussed and set up by using Poisson distribution. Then we analyze the process of traffic evaluation with enhanced learning, and exploit movement estimation to assist state memorization. The improvement of algorithm is provided at last compared with our previous work. Simulation results show that SAREL algorithm could achieve better performance in packet delivery ratio, especially when network connection ratio is average.     

A Chinese Web page clustering algorithm based on the suffix tree

In this paper, an improved algorithm, named STC-I. is proposed for Chinese Web page clustering based on Chinese language characteristics, which adopts a new unit choice principle and a novel suffix tree construction policy. The experimental results show that the new algorithm keeps advantages of STC, and is better than STC in precision and speed when they are used to cluster Chinese Web page.