矿石拣选的新进展

对矿石拣选的新进展做了介绍。目前利用可见光、X射线、γ射线等的机械拣选有了较快的发展,受到各国矿冶界的重视。     

双目立体视觉的无人机位姿估计算法及验证

针对无人飞行器在未知复杂环境下的导航问题,提出了一种基于双目立体视觉的无人飞行器位置和姿态估计算法。用双目摄像机采集立体图像序列,对图像进行立体校正后使用Harris算法提取特征角点,用NCC算法获取匹配特征点,导出摄像机坐标系下的特征点坐标,得到三维立体特征信息,使用RANSAC算法与L-M迭代算法得到无人飞行器姿态和位置估计值。实验结果表明,基于双目立体视觉的位姿估计算法能适应未知环境变化,计算结果与实际位姿量相比误差小,能满足无人飞行器导航要求,可为无人飞行器的导航实现提供一套新途径。     

立体图像对亮度差异对立体视融合的影响研究

针对具有亮度差异的立体图像对如何影响立体融合,提出了对不同亮度差异的立体图像对识别融合的影响范围。通过8名被试对亮度差异分别为0,10,20,30,40,50,60,70,80,90的立体图像对融合识别的反应时和正确率进行分析,给出了亮度差异对立体视融合的定量影响范围。结果表明:反应时随着亮度差异的增大逐渐增加,但识别正确率逐渐降低。亮度差异为20以下,立体识别可达到较好的识别效果,反应时较短并且正确率很高。当亮度差异介于20~60之间,反应时急剧增加,正确率稍有降低。但当亮度差异达到60以上,不仅反应时急剧增加,而且正确率急剧降低,达到很难识别的程度。     

在 C＋＋ Builder中创建立体字的标签组件

以一个带立体字的标签组件创建过程为例,介绍在C＋＋Builder中组件创建过程和方法,对C＋＋Builer用户使用组件有一定的帮助和指导作用。     

靛红褪色分光光度法测定溴酸根离子研究

在盐酸介质中,依据溴酸根离子氧化靛红褪色的原理提出了测定溴酸根离子的新方法,研究了测定的最佳条件。最大吸收波长λmax为610 nm,溴酸根离子在3-40μg／10 mL范围内符合比尔定律,测定的线性回归方程为A610=0．208 0ρ+0．081 6,相关系数为0．993 7,表观摩尔吸光系数为3．7×104。该法用于化学试剂中的微量溴酸根测定,结果满意。     

三氯化锑光度法测定地锦草中槲皮素含量

研究了以丁酮为溶剂三氯化锑与槲皮素生成黄色络合物的测定条件，在４００ｎｍ波长下，槲皮素浓度在４～２０μｇｍＬ－１符合比耳定律，相关系数ｒ为０．９９９３同时探讨了时间、温度、显色剂用量对槲皮素测定的影响，应用该法测定地锦草中槲皮素，变异系数为１．５７％，回收率在１００．２％～１０１．７％之间，结果较为满意。     

Stereo‐PIV experiments and large eddy simulations of flow fields in stirred tanks with Rushton and curved‐Blade turbines

The flow characteristics in pilot‐scale stirred tanks with Rushton and curved‐blade turbines were investigated by using stereoscopic particle image velocimetry (SPIV) experiments and large eddy simulation (LES) methods. The velocity and turbulent kinetic energy (TKE) in the impeller discharge regions were carefully resolved with a high resolution SPIV system, and the detailed phase‐resolved velocity and TKE profiles were used to validate the LES results. The effects of Reynolds number and blade shape on the flow characteristics were discussed. The LES results of velocity, TKE, and the evolution of trailing vortices were compared with the SPIV experimental data, and good agreement was obtained at various phase angles. The effects of subgrid scale model and hybrid grid with different mesh resolutions on the LES results were investigated. LES is a computationally affordable method for the accurate predictions of the complex flow fields in pilot‐scale stirred tanks is presented. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3986–4003, 2013     

基于多尺度注意力网络的立体匹配方法

为解决网络深度与训练图像块大小耦合问题及进一步提高弱纹理区域及边缘处的匹配精度,提出了一种基于多尺度注意力网络的立体匹配方法.该方法将立体匹配过程分为2个阶段：第1阶段提出了一种成本网络用于计算匹配成本,该网络由基础网络层和缩放层组成.第2阶段提出了一种基于多尺度注意力的视差求精网络,该视差求精网络综合了多种视差线索,并加入多尺度注意力机制进一步提高立体匹配精度.该方法在KITTI 2012、KITTI 2015和SceneFlow数据集上的3像素坏点百分比分别为1.13%,1.87%和2.29%.实验结果表明,与国内外同类方法相比,采用多尺度注意力网络的立体匹配方法在匹配精度上获得了较大的提升,尤其是在弱纹理区域及物体边缘处表现较好.     

Yeast‐mediated stereo‐selective reduction of estrone by continuous cell culture with dual stirred tanks for product yield improvement

BACKGROUND: β‐Estradiol is an important hormone for the treatment of breast cancer and osteoporosis. β‐Estradiol can be produced via Saccharomyces cerevisiae mediated reduction of estrone. However, substrate inhibition and low production yield have been observed in the batch cell culture. RESULTS: An innovative continuous cell culture with dual stirred tanks in series was designed to solve the above problems. The growth medium was fed continuously to the incubation tank where the cells were incubated aerobically; the viable cells were then supplied continuously to the reaction tank in which the yeast‐mediated anaerobic reduction of estrone was performed with continuous feed of the substrate medium and continuous withdawal of the reaction cell culture. Thus, an increase in cell productivity from about 3‐fold to 7‐fold was obtained when compared with the batch cell culture. The β‐estradiol yield was improved to 64.8% on the second reaction day, accompanied by an accumulation of 12.9 mg β‐estradiol on the third reaction day. The yield was about 10% more and the accumulated recovery of β‐estradiol was 4.3‐fold better than with the batch cell culture. The diastereomeric excess value (%de) of β‐estradiol was more than 99%. CONCLUSION: A high product yield with excellent stereo‐selectivity was achieved in a short reaction period with the developed continuous cell culture and the dual stirred tank. Copyright © 2010 Society of Chemical Industry     

磺基水杨酸光度法测定循环水中铁

提出一种用磺基水杨酸作显色剂测定循环水中铁的新方法 ,结果表明 :此方法所用仪器简单 ,所需药剂很少 ,简便快速 ,且具有较高的准确性 ,可在生产实际中应用