UG／WAVE技术在叠压夹具设计上的应用

介绍了UG／WAVE的基本功能和叠压央具的设计特点。探讨了运用系统工程和自顶向下的设计原则建立叠压夹具模型的步骤和方法，实现了叠压夹具的高效设计。     

变频调速的原理与控制方法

今年来,由于电力电子技术及大规模集成电路的发展,生产工艺的改进,变频调速已成为工业控制中的重要组成部分。本文主要介绍变频器的工作原理和控制方式。     

金沙江白鹤滩水电站旱谷地料场灰岩工程性状弱化成因

二叠系下统栖霞+茅口组灰岩通常风化程度低、强度高,但白鹤滩水电站旱谷地料场灰岩却出现工程性状弱化现象。为揭示白鹤滩水电站旱谷地料场灰岩工程性状弱化特征及成因,通过对料场及周边地质环境调查,结合钻探、声波测试、室内试验等手段可得:旱谷地料场灰岩弱化后强度仅为新鲜岩体强度的1/2～1/4;料场区弱化岩体可分为强风化带、弱风化带上段、裂隙构造带、溶蚀带;分别分布在泥质含量较高的灰岩透镜体和灰白色灰岩夹泥质微晶灰岩条带、地表P_1q+m-①层、裂隙构造密集带、岩溶溶蚀带;料场灰岩弱化是受灰岩物质成分、构造挤压、岩溶溶蚀作用和风化耦合作用而成。     

控缝高技术在塔河油田碳酸盐岩储层酸压改造中的应用

根据塔河油田碳酸盐岩储层特征,针对塔河油田小跨度井层、裂缝发育及无明显高阻层段的井层,提出储层改造时控缝高的设计思路和方法,并以实例说明各种控缝高工艺在塔河油田储层改造中的成功应用。     

电子气动记录调节器PID调节校验设计

通过对生产使用的电子气动调节器的PID调节校验设计,使得调节器的电子调节、记录显示、以及调节器的机械执行三方面相互吻合,提高调节器的实际调节性能,更有利于对工艺过程参数的控制与计量,从而提高化工生产工艺的控制水平和产品质量。     

CORS系统在地籍测绘中的应用

为使CORS系统的先进测量手段在土地调查中得到充分应用,通过实验结合不同规范要求,总结了利用CORS系统进行地籍测绘的技术方法,并在全省范围内求解了坐标转换参数,大大提高了测量精度和工作效率。     

光耦隔离晶闸管交流调压电路过触发现象研究

该文分析了晶闸管三相交流调压光耦隔离驱动电路中的过触发现象,即以自然换相点为起点,当触发脉冲大于120时,输出电压有效值可能骤然增加的现象。过触发现象可能造成异步电机失控,从而带来破坏性影响。该文通过理论分析、仿真及实验,分析了过触发现象的原因,并给出了避免过触发现象的控制方法。     

Microstructure-based hot extrusion process control principles for nickel-base superalloy pipes

The properties of nickel-base superalloy pipes are determined by microstructure, and the microstructure can be tuned by hot extrusion process. There are two major questions in hot extrusion: one is how to successfully extrude pipes without apparent defects, the other is how to make the microstructure under control. However, up to now, there is no systematical report about hot extrusion process and microstructure control for nickel-base superalloys. In present study, a series of technical control principles for hot extrusion are proposed basing on practical manufacture facts, large amounts of experimental studies and finite element simulation of several typical nickel-base superalloys. The common used technical control principles can be applied for hot extrusion parameters determination to maintain safety hot extrusion and microstructure control. In the investigation of microstructure control based hot extrusion principles, the action rules of different working parameters on hot extrusion field quantities were established. The upper and lower limits of different principles were obtained in consideration of materials characteristics and extruder conditions. The limitations were overlapped on the action rules to determine the optimized hot extrusion parameters. The microstructure-based control principle proposed in present work can provide theoretical guidance for hot extrusion parameter determination and optimization.     

Towards understanding the influence of Mg content on phase transformations in the La3-xMgxNi9 alloys by in-situ neutron powder diffraction study

The present work is focused on the studies of the phase-structural transformations in the La_3-xMg_xNi₉ (x ​= ​1.0, 1.1 and 1.2) alloys as active materials of negative electrodes in the Nickel-Metal Hydride (Ni/MH) batteries. The phase equilibria and phase-structural transformations in the alloys were probed by in situ neutron powder diffraction (NPD) at the temperatures ranging from 300 ​K to 1273 ​K using the measurements of the equilibrated alloys at 8 setpoint temperatures of 300, 973, 1073, 1123, 1173, 1223, 1248 and 1273 ​K.Prepared by induction melting initial alloys were found to be multi-phase structured, containing up to 6 individual intermetallic compounds with different stoichiometric compositions. With the increase of the temperature and holding time, various transformations took place in the studied alloys. These included the formations and transformations of super-stacking intermetallics with variable ratios (La ​+ ​Mg)/Ni, 1:3, 2:7 and 5:19.With increasing temperatures, several systematic changes took place. (a) Abundances of (La,Mg)₂Ni₄ AB₂ and (La,Mg)Ni₃ AB₃ type intermetallics gradually decreased before they melted/decomposed above 1073 ​K; (b) The (La,Mg)₂Ni₇ A₂B₇ type intermetallics began to decrease in abundances above 1123 ​K; (c) The transformation in the (La,Mg)₅Ni₁₉ intermetallics from 3R to 2H proceeded above 1223 ​K.The increase of Mg content had no obvious influence on (La,Mg)₂Ni₄ and (La,Mg)₂Ni₇ phases, and corresponding reactions R1 and R3 took place at the same temperatures as in the La–Ni system. However, with increasing Mg content the melting point of (La,Mg)₅Ni₁₉ phase increased while the melting point of the (La,Mg)Ni₃ phase it decreased, leading to the variation of the reaction temperatures of the corresponding processes.The present study will assist in optimizing phase-structural composition of the alloys in the La–Mg–Ni system which contain Mg-modified layered structures by tailoring the high temperature annealing conditions.     

控制灌溉下三江平原稻田耗水量和水分利用效率研究

采用田测法对三江平原控制灌溉下稻田灌溉水量、耗水量、产量和水分利用效率进行了研究。实验采用控制灌溉Ⅰ、控制灌溉Ⅱ和淹灌3种灌水处理。结果表明：控Ⅰ灌、控Ⅱ灌和淹灌3种处理的总灌溉水量分别为344.1mm、319.4mm和467.4mm,与淹灌处理相比,控Ⅰ灌和控Ⅱ灌处理分别节省灌水26.4%和31.7%。在整个生育期内田测法测得的控Ⅰ灌、控Ⅱ灌和淹灌3种处理的耗水量分别为538.5mm、500.5mm和627.8mm,与淹灌处理相比,控Ⅰ灌和控Ⅱ灌处理分别节水14.2%和20.3%。控Ⅰ灌、控Ⅱ灌和淹灌3种处理的实际籽实产量分别为10 200 kg·hm^-2、10 500 kg·hm^-2和9 320kg·hm^-2,控Ⅰ灌和控Ⅱ灌处理分别增产9.4%和12.7%。控Ⅰ灌、控Ⅱ灌和淹灌3种处理的水分利用效率分别为1.89kg·hm^-3、2.10 kg·hm^-3和1.49 kg·hm^-3,控Ⅰ灌、控Ⅱ灌的WUE分别较淹灌增加26.9%和40.9%。对比分析结果表明,控制灌溉在节约水资源的同时还能提高产量,控Ⅱ灌的节水和增产效果都略优于控Ⅰ灌。图3,表4,参7。