饱和土体中椭圆孔扩张弹塑性解

针对软黏土中的打桩问题,提出一种包含完全排水和完全不排水的柱孔扩张通用求解方法,并基于该方法,采用不排水柱孔扩张理论模拟静压桩打桩过程,并采用修正剑桥模型模拟软黏土的本构关系,同时联立扩孔运动学方程、应力平衡方程、质量守恒方程等建立弹塑性孔扩张偏微分控制方程组,利用相似变换的技术求解该方程组,从而获得半解析解.通过与文献中的解答对比,验证了解答的正确性.

     

Contour finding by means of subjective tests

Abstract

A special method has been found and used for the rapid finding of the contours in a natural image. A reference contour image was thus formed by a subjective test. The reference contour image can be further adopted as an objective criterion for other contour‐finding algorithms.     

A comparison of chitosan-silica and sodium starch glycolate as disintegrants for spheronized extruded microcrystalline cellulose pellets

Chitosan-silica coprecipitate (C-S) has recently been proposed as a tablet disintegrant. In this study we compared it with a 1:1 physical mixture of chitosan and silica (C/S) at the same composition as the coprecipitate, and with the widely used commercial disintegrant sodium starch glycolate (SSG), as regards to its behavior in spheronized extruded pellets of microcrystalline cellulose (MCC) containing hydrochlorothiazide as a typical poorly water-soluble drug. In all three cases, possible synergism between the disintegrant (0–5%) and sorbitol (0–50%) was also evaluated. All the formulations examined exhibited appropriate morphology and had satisfactory mechanical and flow properties. Drug release depended mainly on sorbitol content, however C-S accelerated drug release at all sorbitol levels (the fastest release was from 50% sorbitol pellets with C-S, which disintegrated), whereas C/S did not vary drug release from pellets, and SSG depressed drug release, especially from 50% sorbitol pellets.     

基于集成构架的智能MCC在钾肥项目中的应用

结合国投新疆罗布泊钾盐有限责任公司年产120万吨钾肥项目,介绍了集成架构理念,智能MCC控制方式,从顶层工作站对底层电机监控的实现.     

一种多功能智能低压电动机继电器的研制

本文介绍一款为满足低压电动机控制中心(MCC)智能化要求而设计开发的保护测控装置——智能电动机继电器,它采用高性能混合信号ISPFLASHMCU微控制器,集保护、测量、控制、显示、通讯等众多功能为一体,具有完善的保护测控功能。本文着重介绍其保护功能,并分析装置的软硬件构成。     

热连轧液压泵站控制系统设计与应用

根据热连轧精轧机组HAGC(液压自动厚度控制系统)液压泵站控制系统连续工作时间长、可靠性要求高、信号复杂的特点,以ABB公司AC800M型PLC为基础,对液压泵站的硬件构成、工作过程和程序结构进行设计.该液压泵站控制系统控制精度高、可靠性强,完全满足连轧机液压泵站控制要求,已经成功通过模拟调试,并将应用于生产实际.     

智能MCC控制保护管理装置在厂用电系统中的应用

结合智能MCC控制保护管理装置在贵州大龙电厂扩建工程中的应用,详细介绍了智能MCC控制保护管理装置的基本组成和主要功能。     

金属针布高耐磨的技术瓶颈与突破

为了攻克高速高产梳棉机用金属针布耐磨度不足这一难题,通过检测和研究国外高端金属针布,结合冶金及材料科学、表面技术的最新进展,从材质、工艺处理、设计等方面分析高耐磨金属针布研制的技术瓶颈,研究认为:材质的合金优化、超细晶粒钢、去除脱碳层、特殊表层处理、特殊热处理是有效的突破技术瓶颈的方法,而融合金属针布磨损机理、失效方式、衰退轨迹的高耐磨优化设计创新空间大,前景广阔。     

综合复用技术中基于HDLC的MCC驱动设计

首先介绍了综合复用技术在业务QoS和安全性保障方面的独特优点,然后重点描述了综合复用技术中一种典型的基于HDLC的MCC驱动的开发设计,包括设计思路、HDLC分析、MCC硬件原理、数据处理原理、MCC初始化过程和E1实现模型等.     

Study on the influence of three-grid assembly thermal deformation on breakdown times and an ion extraction process

In order to study the influence of three-grid assembly thermal deformation caused by heat accumulation on breakdown times and an ion extraction process,a hot gap test and a breakdown time test are carried out to obtain thermal deformation of the grids when the thruster is in 5 k W operation mode.Meanwhile,the fluid simulation method and particle-in-cell-Monte Carlo collision(PICMCC) method are adopted to simulate the ion extraction process according to the previous test results.The numerical calculation results are verified by the ion thruster performance test.The results show that after about 1.2 h operation,the hot gap between the screen grid and the accelerator grid reduce to 0.25–0.3 mm,while the hot gap between the accelerator grid and the decelerator grid increase from 1 mm to about 1.4 mm when the grids reach thermal equilibrium,and the hot gap is almost unchanged.In addition,the breakdown times experiment shows that 0.26 mm is the minimal safe hot gap for the grid assembly as the breakdown times improves significantly when the gap is smaller than this value.Fluid simulation results show that the plasma density of the screen grid is in the range 6?×10~(17)–6?×?10~(18) m~(13) and displays a parabolic characteristic,while the electron temperature gradually increases along the axial direction.The PIC-MCC results show that the current falling of an ion beam through a single aperture is significant.Meanwhile,the intercepted current of the accelerator grid and the decelerator grid both increase with the change in the hot gap.The ion beam current has optimal perveance status without thermal deformation,and the intercepted current of the accelerator grid and the decelerator grid are 3.65 m A and 6.26 m A,respectively.Furthermore,under the effect of thermal deformation,the ion beam current has over-perveance status,and the intercepted current of the accelerator grid and the decelerator grid are 10.46 m A and 18.24 m A,respectively.Performance test results indicate that the breakdown times increase obviously.The intercepted current of the accelerator grid and the decelerator grid increases to 13 m A and 16.5 m A,respectively,due to the change in the hot gap after 1.5 h operation.The numerical calculation results are well consistent with performance test results,and the error comes mainly from the test uncertainty of the hot gap.