带气液分离器自动复叠系统中节流阀开度引起的混合工质浓度偏移(英文)

Auto cascade refrigeration (ACR) cycle with phase separators is widely used in the cryogenic system. The compo-sition of mixed refrigerant has a great effect on the performance of the system. Based on the assumption of infinite volume of phase separator, ACR system with one phase separator is simulated in this paper. The variation of refrigerant composition under different valves opening is obtained. A related experimental system is set up to verify the variation. The result shows that when the valve opening connected to the evaporator increases or the valve opening under the phase separator decreases, the low-boiling component concentration of the working mixture passing through the compressor and condenser increases, while the high-boiling component concentra-tion decreases. Furthermore, the variations of condensation pressure and evaporation pressure under different valves opening are also observed. This paper is helpful to deepen the understanding of ACR system.     

隧道安全预警机器人自主导航方法研究

针对隧道施工环境,设计了一款隧道安全预警机器人,并重点研究其导航系统实现;机器人搭载检测仪器与分析主机,集数据采集、分析、预警于一体,实现隧道巡检的自动化和智能化;分别利用Cartographer算法和自适应蒙特卡洛算法(AMCL)融合雷达、里程计、IMU的数据,实现环境地图的创建与机器人实时定位;采用A * 算法和DWA算法实现机器人的全局和局部路径规划,并结合ROS操作系统对其进行实验验证;实验结果表明:在导航定位时,机器人位置误差和航向误差分别小于20 cm和5.5.,能满足实际工程需要,完成自动巡检任务.     

房屋面积测算的方法及其计算机的应用

主要就房产测绘中房屋面积测算的方法进行了论述,并就其中计算机的应用进行了探讨,着重介绍了面积测算的作业流程及利用Auto Lisp语言用户化AutoCAD的方法,从而给绘图和计算工作带来方便,提高了工作效率。     

恒水位自控装置的开发及应用

本文介绍了一种多功能水位自控装置的设计过程及在汕头市丹霞庄供水加压泵站的应用情况。该装置具有控制效果好、操作方便、功能齐全、性能稳定、价格便宜、维护简单等优点，有较高的创新意识及实用价值。     

一种关于AutoCAD软件快速绘制三视图的作图方法

在绘制形体的三视图时,如果已知两个视图,要绘制的第三视图是左视图或者是俯视图,常用的作图方法是使用一条45°辅助线。这种作图法被习惯性地应用到Auto CAD软件绘图教学中。在Auto CAD软件绘图环境中这种传统的方法绘图效率低。文中通过实例提出一种应用于Auto CAD绘图环境下绘制三视图的作图方法,这种新的作图方法的原理是基于将传统45°辅助线作图法中俯视图、左视图相应尺寸的"宽相等",转化为相应尺寸的"长对正"或"高平齐"的过程。新方法比传统45°辅助线作图法更加简单、直接,且效率高。     

A low phase noise and low spur PLL with auto frequency control circuit for L1-band GPS receiver

A low phase noise and low spur phase-locked loop (PLL) for L1-band global positioning system receiver is proposed in this paper. For obtaining low phase noise for PLL, All-PMOS LC-VCO with varactor-smoothing technique and noise-filtering technique is adopted. To reduce the reference spur, a low current-mismatch charge pump is carefully designed. A quasi-closed-loop auto frequency control circuit is used to accelerate the lock process of PLL. The PLL is fabricated in 180 nm CMOS Mixed-Signal process while it operates under 1.8 V supply voltage. The measured output frequency of PLL is 1.571 GHz and output power is −1.418 dBm. The in-band phase noise is −98.1 dBc/Hz @ 100 kHz, while the out-band phase noise is −130.3 dBc/Hz @ 1 MHz. The reference spur is −75.8 dBc at 16.368 MHz offset. When quasi closed-loop AFC is working, the measured lock time is about 10.2 μs.     

Nanograin Mn-Zn ferrite smart cores to miniaturize electronic devices

Conventional ceramic and sol-gel auto combustion routes were adopted to develop Mn-Zn ferrite cores. To control high frequency (>500 kHz) losses, zirconia (0.2 wt%) and calcia (0.04 wt%) were added in Mn_0.57Zn_0.35Fe_2.08O₄. The results revealed that Mn-Zn ferrite smart cores synthesized by auto combustion process have superior properties than conventionally prepared cores. It is believed that the presence of unique properties such as nanograin microstructure, light weight and short height (thickness) dimensions have played their role to enhance the magnetic impedance of smart core to manifold. Fabricated smart core excellently performed in a test frequency band of 3-15 MHz.     

汽车板连续退火机组工艺布置与设备配置探讨

介绍了带钢连续退火机组的发展概况和普冷汽车板连退机组的特点,并在此基础上探讨了汽车板连续退火机组的工艺布置和设备配置,确保在实际生产中机组生产出优良的并满足下游工序要求的产品。     

多功能热泵热水机组控制系统的研究

着重介绍了多功能热泵热水机组的各种功能运行模式,以及各种运行模式的控制逻辑、测控点参数、报警设置等;同时介绍了除霜控制的运行及判断条件。