基于改进 U-Net 的金具图像小样本识别算法研究

电力金具巡检是保证电网安全运行的关键任务。针对因金具样本类别不平衡、金具图像背景复杂而导致的误检、漏检问题,提出了一种改进U型网络(U-shaped network, U-Net)的检测方法。首先,通过生成对抗网络生成虚拟金具样本扩充数据集,解决数据集中样本类别不平衡的问题;然后,提出一种前景增强方法,在网络输出的特征图中加入背景掩膜,并优化损失函数;最后,将注意力机制嵌入U-Net,以提高模型在复杂背景下提取金具特征的能力。经实验证明,改进算法对电力金具目标的检测效果良好,其金具检测准确率达到98.82%,平均交并比达到83.94%,精确率达到91.01%,召回率达到86.18%,平均精度均值达到89.73%。改进算法不仅可应用于正常金具的检测,还有效适用于生锈金具的检测,为电力金具智能化检测提供了一种新思路。     

Biological Detoxification of Mycotoxins: Current Status and Future Advances

Mycotoxins are highly toxic metabolites produced by fungi that pose a huge threat to human and animal health. Contamination of food and feed with mycotoxins is a worldwide issue, which leads to huge financial losses, annually. Decades of research have developed various approaches to degrade mycotoxins, among which the biological methods have been proved to have great potential and advantages. This review provides an overview on the important advances in the biological removal of mycotoxins over the last decade. Here, we provided further insight into the chemical structures and the toxicity of the main mycotoxins. The innovative strategies including mycotoxin degradation by novel probiotics are summarized in an in-depth discussion on potentialities and limitations. We prospected the promising future for the development of multifunctional approaches using recombinant enzymes and microbial consortia for the simultaneous removal of multiple mycotoxins.     

X射线衍射法研究大电机定子绝缘的老化过程

绝缘老化过程和老化机理的研究是电力设备绝缘状态监测和状态诊断技术的基础.本文研究绝缘常用材料云母在大电机运行应力作用下的老化过程.对300MW/18kV发电机运行23年的定子线棒绝缘进行X射线衍射实验,通过衍射图谱分析绝缘中云母晶体的化学式,探讨了云母的老化过程.结果表明:在运行应力尤其是局部放电的长期作用下,定子绝缘中所有云母晶体都发生了复杂的变化,K原子数由老化前的1减小为0.75,Al离子被Fe离子和Li离子置换,羟基被F离子置换等.但还很难解释其复杂过程.     

基于InTouch组态软件的变电站自动化监控系统

介绍了Invensys旗下Wonderware公司的HMI产品InTouch在变电站监控系统中的应用.     

95氧化铝瓷用高温釉的研究

本文针对95氧化铝瓷的性能要求,用正交实验法优选出了瓷釉配方,在1530℃研制出性能稳定、釉面光滑、光泽好、坯釉适应性好、介电性能良好的瓷釉配方。     

A Novel Yolk–Shell Fe3O4@ Mesoporous Carbon Nanoparticle as an Effective Tumor-Targeting Nanocarrier for Improvement of Chemotherapy and Photothermal Therapy

Owing to their good stability and high photothermal conversion efficiency, the development of carbon-based nanoparticles has been intensively investigated, while the limitation of unsatisfactory cellular internalization impedes their further clinical application. Herein, we report a novel strategy for fabrication of Fe₃O₄ yolk–shell mesoporous carbon nanocarriers (Fe₃O₄@hmC) with monodispersity and uniform size, which presented significantly higher cell membrane adsorption and cellular uptake properties in comparison with common solid silica-supported mesoporous carbon nanoparticles with core–shell structure. Moreover, the MRI performance of this novel Fe-based nanoparticle could facilitate precise tumor diagnosis. More importantly, after DOX loading (Fe₃O₄@hmC-DOX), owing to synergistic effect of chemo–phototherapy, this therapeutic agent exhibited predominant tumor cell ablation capability under 808 nm NIR laser irradiation, both in vitro and in vivo. Our work has laid a solid foundation for therapeutics with hollowed carbon shell for solid tumor diagnosis and therapy in clinical trials.     

循环流化床脱硫灰用于水泥生产的研究

褐煤作燃料热电厂产生的循环流化床脱硫灰应用于我公司2 500 t/d新型干法窑生产线水泥生产,由于褐煤中全硫含量偏高且波动大,由此致使脱硫过程中脱硫剂比例变化波动也大,将熟料、矿渣、脱硫灰分别用小磨粉磨后进行试验,在试验基础上,除了对该脱硫灰超细粉磨外,同时必须要解决脱硫灰的均化和f-CaO消解问题,通过技术改造使系统设备、工艺更加适合采用脱硫灰复掺技术。     

露天采场高陡边坡下深部采空区的爆破处理研究

鞍本地区是我国最大的BIF型铁矿集中分布区,其铁矿资源量/储量约占全国总量的1/4,但由于日伪时期的掠夺式开采和矿业整合开发前的无序开发利用,在一定深度空间内遗留了大量隐伏采空区,为后期实现规模化露天开采带来极大的安全隐患,成为制约露天铁矿资源安全高效开采的难题。以弓长岭露天铁矿大砬子采区高陡边坡下的深部采空区为研究对象,利用LS_DYNA软件进行采空区的安全爆破模拟研究,结合现场深部采空区爆破参数试验结果,提出了采用孔中起爆处理采空区的方法,具体参数设置为空区预留顶板厚度3 m,孔间延期时间42 ms,排间延期时间75 ms,平均炸药单耗0.237 kg/t。在上述分析的基础上,针对大砬子露天采场高陡边坡内的深部不规则多层采空区提出了分层、分区安全爆破处理的技术方案,且空区边界用切割爆破方法处理,爆破处理效果良好,采空区得到了安全有效治理。     

Oxygen concentration measurement and control of lead-bismuth eutectic in a small,static experimental facility

ABSTRACT

Oxygen measurement and control system is critical for minimizing corrosion in nuclear systems. Oxygen measurement and control tools use lead-bismuth eutectic (LBE) and pure lead as a coolant or as a spallation target. Oxygen can be supplied by either gas phase (H₂O or O₂) or solid phase (PbO dissolution); thus, oxygen control includes both gas phase and solid phase methods. This article focuses on oxygen concentration measurement and control of lead-bismuth eutectic in a small, static experimental facility. This facility was developed for oxygen sensor calibration and gas/solid phase control systems test programs. The oxygen sensor with Nano Cu/Cu₂O closely the Nernstian behavior down to 195°C; the oxygen sensor measurement accuracy satisfied the requirements of subsequent experiments. The gas phase control system (verified according to different type of mass transfer, such as air, H₂O, gas injection, and coverage) and the solid phase control system were very successful in small experimental devices. Accurate oxygen concentration control was achieved with both the gas and solid phase control systems.