用PLC改造600kN塑压机控制系统

简述了塑压机的功能、PLC与继电器的区别、PLC程序的设计方法。采用PLC改造了原600kN塑压机的继电器控制系统,解决了原有电气系统的弊端,大大提高了塑压机的性能。

运用塑压机成形大型件陶瓷产品的研究

本文详细说明了运用塑压成形机生产大件异型制品的过程,并对塑压成形的机理进行了分析,对其辅助工具通气管、过渡模、子模、工作模的制作、压坯整个过程进行了全面的阐述。

奥地利企业将加大大锁模力注塑机投产力度

奥地利企业威猛巴顿菲尔集团有关高层表示，公司今年将加大大吨位注塑压机扩产，提高2013上销售量。该公司计划让其锁模力达1600t的大吨位注塑机在明年K展中亮相。

Antihypertension and anti-cardiovascular remodeling by phenylalanine in spontaneously hypertensive rats: effectiveness and mechanisms

odeling · mechanismObjective To investigate mechanisms of anti hypertension and anti cardiovascular remodeling by phenylalanine (phe) in spontaneously hypertensive rats (SHRs) Methods The comparison of blood pressure (BP) increment with the ages and cardiovascular changes of SHRs was made between the 3% phe intervented group (SHR phe) and the control SHRs group Detection of the structural changes with the VIDAS digital vedio frequency processing technique and light and electron microscopy were made The cell growth and proliferation of cultured smooth muscle cells (CSMCs) of the thoracic aortas or myocardial fibroblasts were evaluated by measuring the 3 H thymidine counts per minute (cpm) incorporated into the new synthesized desoxyribonucleic acid (DNA) and determining the cell number with the crystal violet stain technique The Ca 2+ influx was measured in counts/min of 45 CaCl 2 after incubating it with 5 different concentrations of phenylalanine and the intracellular [Ca 2+ ] i by Fura Ⅱ/Am indicator The total messenger ribonucleic acid (mRNA) of the myocardium was extracted and Northern blot analysis was performed with the probe collagen α 2(Ⅰ)cDNA The tyrosine hydroxylase (TH) activity was measured by high performance liquid chromatography (HPLC) with electrochemical detector after having reacted with its substrate tyrosine and other reagents The catecholamine contents in brain homogenat were detected by HPLC method The comparison of pharmacokinetics of phenylalanine among SHR phe, SHRs and control Wistar Kyoto (WKY) rats was made after intravenous injection of 3 H L phe (1?ml/kg) by PK GRAPH Program for kinetic calculation The 3H L phe uptake by CSMCs after incubating for difinite intervals was also detected and compared Results Phenylalanine could prevent the increase of BP with ages and the heart weight (heart/body weight index) The aortic media thickness and the collagen content in the myocardium were decreased significantly in SHR phe Whereas the dearranged cardiovascular structure was much improved The mechanisms might be direct and specific inhibition of the DNA synthesis and proliferation of cardiovascular cells which may be related to the inhibition of collagen α 2(Ⅰ)cDNA, c fos and c myc expression Other mechanisms may include decrease of intracellular [Ca 2+ ] i and an inhibition of central sympathetic activity due to the results of higher TH activity in the caudate nucleus and higher adrenaline content in the posterior hypothalamus Besides, partial recovery of phenylalanine metabolic aberrants existed in SHRs seems to be another possibility for its effectiveness Conclusions Phenylalanine intervention could exert a definite anti hypertension and anti cardiovascular remodeling effects on SHRs like seen in human essential hypertension Its mechanisms might be related to direct inhibition of growth in the cardiovascular cells, decrease of central sympathetic activity, the reverse of the exhibited phenylalanine metabolic aberrants in SHRs, and a decrement of intracellular [Ca 2+ ] i

Forging Penetration Efficiency of Steel H13 Stepped Shaft Radial Forging with GFM Forging Machine

The numerical thermal mechanical simulation of radial forging process of steel H13 stepped shaft with GFM(Gesellschaft fur Fertigungstechnik und Maschinenbau) forging machine was carried out by three-dimensional finite element code DEFORM 3D.According to the effective plastic strain,the mean stress and the mean plastic strain distribution of the radial forging,the forging penetration efficiency(FPE) was studied throughout each operation.The results show that the effective plastic strain in the center of the forging is always greater than zero for the desirable larger axial drawing velocity.The mean stress in the center of the workpiece is proposed to describe hydrostatic pressure in this paper.There is compressive strain layer beneath the surface of the workpiece to be found,while there is tensile strain core in the center of the workpiece.These results could be a valuable reference for designing the similar forging operations.

Review on modified and novel techniques of severe plastic deformation

This review highlights very recent achievements and new developments of severe plastic deformation(SPD) technology for producing bulk ultrafine-grain(UFG) and even nanocrystalline(nc) materials.These numerous modified and novel SPD methods include cyclic forward-backward extrusion,axi-symmetric forward spiral extrusion,vortex extrusion,simple shear extrusion,planar twist extrusion,tubular channel angular pressing,cone-cone method,high-pressure tube twisting,tube channel pressing and elliptical cross-section spiral equal-channel extrusion.According to classification,these new methods are categorized into the extension of equal-channel angle pressing(ECAP),high-pressure torsion(HPT),twist extrusion(TE) and constrained groove pressing(CGP),respectively.The principles of various new SPD technologies are described in detail.In addition,the microstructure revolution characteristics and mechanical properties of materials produced by SPD process,as well as the applications of SPD techniques to UFG materials,are also reported.Furthermore,this article reviews recent progresses in determining the refinement and/or deformation mechanisms,e.g.dislocation deformation mechanism,twin deformation mechanism and grain boundary sliding and torsional deformation mechanism,and further orientation of SPD technology.