Feasibility of the indirect determination of blast-induced rock movement based on three new hybrid intelligent models

Engineering with Computers - The indirect and accurate determination of blast-induced rock movement has important significance in the reduction of ore loss and dilution and in the protection of...     

数控化改造外圆磨床砂轮成形修整的应用

介绍了基于国产经济型开通数控系统改造的数控外圆磨床MKA1320/H的方法,针对数控外圆磨床复杂曲面砂轮的成形修整问题进行研究,通过开通数控开放式编程环境,完成了砂轮成形修整的数控编程,最后给出了完整程序。     

体系对抗条件下红外导引头探测系统建模与仿真

分析了红外导引头探测系统的设计要求,建立了仿真系统的体系结构,描述了各子模块的功能、组成、模型原理,最后在基于组件的一体化建模仿真环境(CISE)下给出了红外导引头探测系统的仿真实现。体现了实战要素对探测系统的影响,为体系对抗条件下红外导引头的建模仿真提供了参考。     

浅谈机床领域的电磁干扰问题

阐明电磁干扰问题一直是技术人员在机床调试、维修过程中经常遇到的问题.介绍了提高机床电气系统抗干扰的措施以及在实际的机床调试、维修过程中遇到的故障举例及解决方案.     

Brush-type amphiphilic polystyrene-g-poly(2-(dimethylamino)ethyl methacrylate)) copolymers from ATRP and their self-assembly in selective solvents

A series of well-defined brush-type amphiphilic polystyrene-g-poly(2-(dimethylamino) ethyl methacrylate)) (PS-g-PDMAEMA) copolymers were successfully synthesized via atom transfer radical polymerization (ATRP), using chloromethylated polystyrene (CMPS) as the macroinitiator. The self-assembly behavior of the resulting brush-type copolymers in deionized water and deionized water/acetone (v/v=2/3) mixture was studied by high performance particle sizer (HPPS). The results showed that the Z-average size of the micelles in deionized water increased with the increase of molecular weight of PDMAEMA, and the corresponding size was larger than that in mixed solvent of deionized water and acetone (v/v=2/3). The morphologies of the micelles self-assembled from PS-g-PDMAEMA in selective solvents were studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). When the micelles were prepared in water/acetone (v/v=2/3) mixture and cast them on a glass slide at different temperatures (from 50 up to 200 °C), the transformation of the morphologies of aggregates, from needle-like solid to microcubic particles, was observed using SEM.     

Microstructure and Tensile Strength of the Bonded Interfaces and Parent Materials in W/ODS Steel Joints Fabricated by Direct SSDB

In the present work, Tungsten (W)/oxide dispersion strengthened (ODS) steel joints were fabricated by the direct solid state diffusion bonding (SSDB) technology with a multistage cooling process, and the microstructure and tensile strength of the bonded interfaces and parent materials were experimentally investigated. The results show that W and ODS steel can be successfully bonded at the temperature ranging from 900 °C to 1050 °C, without severe macroscopic deformation or obvious microscopic defects. Reaction layers generated at the bonded interfaces are evolutive with the bonding temperature, result in different fracture locations of the bonded joints. In the joint bonded at 950 °C, a higher interfacial strength of ~ 234.2 MPa is achieved, due to the formation of nano-scale intermetallic compound FeW. Microstructure of W remains stable after all the SSDB processes, while the lath structure of ODS steel is completely broken and transformed into the equiaxed grains, which should be responsible for the deterioration of strength. When the bonding temperature is higher than 950 °C, the pinning effect of precipitates M₂₃C₆ and nano-oxide particles on the movement of dislocations is observed.

     

新型电源快速切换方法的研究与实现

快切装置支持不同的切换方法：快速切换,同相捕捉切换,残压切换等。快速切换在理论上是最优的切换方法。快速切换的切换速度越快,负荷断电时间越短,切换时对备用电源和电动机负荷造成的电流冲击和扭矩冲击越小。但在实际应用时,快速切换的定值难以整定,容易错过快速切换的时机。本文基于对母线残压特性和切换过程中冲击响应的研究和分析,提出了一种新型的基于残压特性预测的实时快速切换的方法,并且分析了实时快速切换的优缺点。     

超低功耗井下监测仪器设计

通过对常见集成电路工作模式及其功耗的分析；提出一种适合在油井下工作的超低功耗数据采集系统的设计方法。由于降低了系统功耗，因此，不需要电缆供电就可以在不影响正常生产的情况下完成对油井生产过程的动态监测。此餐，该设计方法将看门狗监控电路与降低功耗结合在一起，在降低系统功耗的同时提高了系统可靠性。实验说明，该系统在断续工作状态下也能正常采集数据。最后，给出了一个实际系统在各种没荼模式下的实际工作电流值。