Reaction process of monazite and bastnaesite mixed rare earth minerals calcined by CaO-NaCl-CaCl2

The decomposition reactions of monazite and bastnaesite mixed rare earth minerals calcined by CaO-NaCl-CaCl2 were studied by means of TG-DTA and XRD. The results show that the process of the minerals decomposed by CaO involves two steps. The first step occurs in the temperature range of 425-540 ℃, and the main reactions are bastnaesite decomposition, i.e. REOF reacts with CaO to produce RE2O3 and CaF2, and Ce2O3 is oxidized to CeO2. During this step, CaCO3 is formed at about 500 ℃. The second step takes place in the temperature range of 610-700 ℃, and the reactions are monazite decomposition into RE2O3, Ca5F（PO4）3 and Ca3（PO4）2 by CaO and CaF2. In this process, the decomposition ability is improved because CaO from CaCO3 decomposing has high chemical activity. In calcining process, the new formed Ca5F（PO4）3 restrains fluorine that can escape in form of gaseous compound. The decomposition ratio of the mixed rare earth minerals reaches 90.8% at 700 ℃.     

MATLAB在数字信号处理中的应用

介绍了数字信号处理及MATLAB的特点。以窗函数法设计有限冲激响应（FIR）数字滤波器（DF）为例，说明了MATLAB在数字信号处理中的应用。     

USB2.0技术在光电测量系统中的应用

针对光电测量系统的特点，介绍了一种基于外设控制器CY7C68013的光电测量系统运用USB2．0接口技术实现通讯的方案；文中详细给出了硬件原理图、数据传输方式以及软件设计内容。仿真实验表明该设计方案是合理可行的。     

境外农药产品中禁限用的助剂及相关杂质名单(二)——西班牙和德国禁限用物质

介绍了西班牙和德国农药产品中禁限用助剂及相关杂质名单。     

A nonlinear optical loop mirror-based linear cavity swit- chable multi-wavelength erbium-doped fiber laser

A nonlinear optical loop mirror (NOLM)-based linear cavity switchable multi-wavelength erbium-doped fiber (EDF) laser is proposed and experimentally demonstrated. Due to the characteristics of the intensity-dependent transmissivity, the NOLM can effectively mitigate the mode competition of the homogenous broadening gain medium, so that the multi-wavelength lasing can be achieved at room temperature. By adjusting the states of the polarization controllers (PCs), the number of the lasing wavelengths in the proposed laser can be adjusted flexibly from 11 to 13 with a wavelength spacing of 0.4 nm around the wavelength of 1 530 nm.     

极端气候条件下沙漠地区混凝土施工工艺

塔克拉玛干沙漠中部夏季温度高达50℃,冬季最低温度-27℃,加上沙尘暴天气影响,给油气田地面工程建设混凝土施工带来巨大挑战。针对塔克拉玛干沙漠中部特殊气候条件,结合国家标准规范及工程实际,提出了适合极端气候条件下沙漠地区混凝土工程施工工艺。该工艺有效的消除了夏季高温条件下混凝土易发生塑性裂缝,冬季低温条件下混凝土易发生冻伤的质量问题,缩短了工程工期,对类似工程施工具有参考价值。     

基于LabVIEW分数阶控制器的机械臂控制

针对机械臂存在着参数摄动和外界干扰等不确定性,提出一种基于Lab VIEW分数阶控制器的机械臂控制方法,以提高机器人的跟踪控制精度和鲁棒性。在CompactRIO智能实时控制器和机箱的基础上利用NI9401对伺服电机的编码器信号进行采集处理,Lab VIEW软件编程控制NI9263输出模拟电压信号到伺服驱动器实现电机的力矩控制,算法采用分数阶PD控制器实现二自由度机械臂高速和高精度的运动控制,通过实验说明了该方法的工程有效性和可行性。     

矿井空气热力参数数字化平台的开发

借助国内外成熟的理论,开发出实用的空气处理过程、冷热负荷计算以及热湿环境评价的数字平台,能绘制任意大气压(标高)时的空气焓湿图及提供空气热力参数计算器,技术误差小于1%,可作为矿井降温技术人员从事工程设计和研究时的动态工具。