4A和13X分子筛去除水中重金属Cd2＋及其吸附性能研究

以4A和13X分子筛为吸附材料,考察废水pH值和Cd2＋初始浓度等对Cd2＋去除率的影响,并研究了分子筛对Cd2＋的吸附性能。结果表明,4A和13X分子筛投加量为0．16 g/L、废水pH值为5、Cd2＋浓度为20 mg/L时,Cd2＋去除率达到95％以上;分子筛对Cd2＋的去除机理以离子交换吸附为主,交换出来的Na＋与分子筛吸附的Cd2＋摩尔浓度比为2;在吸附热力学和动力学方面,4A和13X分子筛均符合Langmuir吸附等温模型和Lagergren二级速率方程,计算的饱和吸附容量 Q0分别为150．15、163．67 mg/g ,二级反应速率常数K2分别为2．45＆#215;10-3、3．96＆#215;10-4 g/（mg ＆#183; s）。该吸附反应是一种单分子层反应速度较快的化学吸附过程。     

光导热塑记录系统在火药包覆质量激光全息无损检测中的应用

本文利用新型记录系统——光导热塑记录系统,代替了通常所采用的全息银盐干版,使激光全息无损检测摆脱了暗室,为以后装机,并使之应用于工厂实际检测奠定了基础;另外还总结了一条适合检测火药包覆质量的典型光路,获得清晰的全息条纹图案.     

Microstructure evolution during reheating of a Nb-bearing steel I. Metallographic examination

Cooled in water after the isothermal relaxation of deformed austenite for different timea, a Nb-bearing microalloyed steel always exhibits synthetic microstructures of bainitic ferrite, granular bainite and acicular ferrite. When these samples were reheated to and held at 650 or 700℃, the non-equilibrious microstructures tend to evolve into equilibrious ones. The sample relaxed for 60 s displays the highest thermostability, while the microstructure evolution is the quickest in the sample relaxed for 1000 s even though it is the softest before reheating. Softening is not a single process occurring during reheating, in which the hardness fluctuates with time. There are two peaks in the hardness-time curve of each sample having undergone relaxation, while a single peak occurs in the curve of the sample having not been relaxed. Pre-strain accelerates the evolution process. These results indicate that the thermostability of microstructures is determined by their history of formation to a considerable degree.     

基于波形非线性映射的多局部放电脉冲群快速分类

简单分析了目前基于脉冲峰值-时间序列的局部放电检测系统在模式识别功能上存在的缺陷.提出利用基于单个脉冲波形的宽带检测技术研制多局放检测与模式识别系统,并给出了研制交流下该系统的数据处理方案.重点对研制该系统需要解决的脉冲群快速分类技术进行了阐述:即通过基于局放脉冲时域波形的非线性映射进行参数提取,形成2D或3D的波形特征参数空间,再使用非监督的模糊聚类分析实现局放脉冲群的快速分类.基于2D特征参数平面的仿真试验和3D特征参数空间的GIS污秽试验数据处理结果均表明该分类技术的可行性和实用性.这为多局放电检测与模式识别系统的研制提供了试验和理论依据.     

基于CBS的人体安检图像组合增强方法

在X射线人体康普顿背散射(CBS)安检系统中,图像的清晰度对于识别隐匿在人体上的违禁品非常重要.根据人体CBS图像的特点,从人眼视觉感知的特点出发,提出了一种图像组合增强方法,明显改善了图像质量,获得了层次清晰、轮廓分明、背景均匀的CBS图像.     

Superior–Subordinate Relationships in Korean Civil Engineering Companies

The Leader–Member Exchange (LMX) relationship quality between superiors and subordinates in Korean civil engineering companies were empirically examined for superiors’ feedback-seeking behaviors. The results showed that for superiors, affect, loyalty, and contribution toward subordinates were positively related to seeking negative as well as positive feedback from subordinates. From subordinates’ point of view, affect, contribution, and professional respect toward their superiors were positively related to superiors’ negative feedback seeking, but affect was negatively related to superiors’ positive feedback seeking. It was also found that superiors and subordinates were not consensual in LMX and superiors’ feedback-seeking behaviors. For example, for superiors, all of the four LMX dimensions were positively related to superiors’ asking subordinates directly for feedback, whereas for subordinates, none of the LMX dimensions were significantly related to superiors’ asking subordinates directly for feedback. These and other findings are discussed in detail, and implications for the findings are provided.     

基于最优占空比的风力发电机MPPT方法研究

针对目前已有的最大功率跟踪(MPPT)控制方法的不足,为提高风力发电的最大风能利用效率,根据风力发电机和boost变换器的输出特性,在变风速条件下,通过给定最佳机械转矩,直接计算最优占空比,控制风机电磁转矩,实现最大功率追踪控制.针对GP-300和FD-5型直驱式永磁风力发电机,进行功率跟踪控制仿真实验,实验结果表明所提出方法的有效性和可靠性,并具有良好的工程应用前景.     

无动力快速浮选在山东某黄金矿山的应用

山东某黄金矿山选矿厂由于浮选工艺流程中旋流器与取样机之间高差较大,以致溢流矿浆流速快、动能大,易造成对管路、弯头及取样机缓冲箱的冲击磨损。鉴于此,在旋流器溢流进入浮选粗选前增加快速浮选槽,以充分利用矿浆的动能,将原浮选工艺流程前增设无动力快速浮选工艺,并对改造后工艺流程结构进行了优化,将原三次扫选改为二次扫选。无动力快速浮选工艺的应用,不但节约了能耗,而且提高了金回收率,其由改造前的91.69%提高到93.06%,生产指标较好。     

Aligning Crystal Orientation of Poly-Crystalline Bi-Te With a High Magnetic Field

We investigated the effect of aligning crystal orientation in the microstructures containing sub micro-sized grains on the thermoelectric properties for polycrystalline Bi-Te materials.Bi-Te powder,prepared through the conventional pulverization process,was sufficiently dispersed in an appropriate solvent,and then was formed into c-axis aligned green bodies under a designated high magnetic field.The green bodies were sintered with spark-plasma-sintering machine.The degree of crystal alignment of sintered bodies was examined with the electron-back-scatter-diffraction SEM and the X-ray diffraction patterns.It was observed that for both p and n type thermoelectric Bi-Te materials,aligning crystal orientation properly made electrical resistivity decreased with keeping Seebeck coefficient and thermal conductivity remained unchanged.As a typical result,the aligned Bi-Te material with the magnetic field of 10 tesla showed 30%enhancement of the thermoelectric performance.     

粉末冶金真空炉专用新型热电偶与在线原位校准

从粉末冶金行业的精确生产与优质高效的战略出发,简述粉末冶金行业用钨铼热电偶的特点、分类与使用。详细论述粉末冶金真空炉专用超高真空(10~5 Pa)、超高压(15 MPa)密封式热电偶及炉温均匀性测试等新型传感器。详细探讨真空炉测温准确度的影响因素:真空度、发射率、热导率、热响应时间及热电偶的插入深度、热电偶保护管的选择等;简介进口真空炉专用热电偶国产化研究,国内外温度传感器性能对比及替代进口真空炉热电偶的成功业绩。目前,对测温系统的检定,多采用分立元件法,即对构成测温系统的元件及仪表分别进行检定。此种检定方法是离线的。本文简述离线式检定方法的诸多弊端以及美国宇航标准(AMS 2750E)中,有关系统准确度校准的特点及要求。详细论述在线原位校准的最新理念,最佳的系统准确度校准方案,并开发出与其配套、行之有效的带有校准孔的热电偶及便携式在线校准仪。为了提高测温系统的准确度,建议采用在线原位校准,方便易行,现已在国内推广应用。