A Two-Stage Particle Swarm Optimization Algorithm for MPPT of Partially Shaded PV Arrays

The power-voltage (P-V) characteristic curves of a PV array are nonlinear and have multiple peaks under partially shaded conditions (PSCs). This paper proposes a novel maximum power point tracking (MPPT) method for a PV system with reduced steady-state oscillation based on a two-stage particle swarm optimization (PSO) algorithm. The grouping method of the shuffled frog leaping algorithm (SFLA) is incorporated in the basic PSO algorithm (PSO-SFLA), ensuring fast and accurate searching of the global extremum. An adaptive speed factor is also introduced into the improved PSO to further enhance its convergence speed. Test results show that the proposed method converges in less than half the time taken by the conventional PSO method, and the power is improved by 33% under the worst PSCs, which confirms the superiority of the proposed method over the standard PSO algorithm in terms of tracking speed and steady-state oscillations under different PSCs.     

基于正交变频的无线电扩频信标设计与实现

无线电信标是船载无线电测控设备进行动态自检和角度标校的必需设备。提出了一种基于正交变频技术的信标设计方法,通过单片机控制实现了信标参数的灵活设置,在电路实现上则采取了抑制边带和本振泄露的措施。该信标工作可靠,性能满足需求,实际应用取得了良好的效果,为船载无线电测控设备的海上标校提供了技术保障。     

排污权交易之排放跟踪数据校核研究

本文以排污权交易的核心业务排放跟踪管理为出发点,选择电厂二氧化硫指标进行排放跟踪数据过程校核体系研究,探索进一步提高排污权交易体系中排放数据准确性的机制。     

Application of a novel open-source program for measuring the effects of toxicants on the swimming behavior of large groups of unmarked fish

The aim of this study was to demonstrate a novel method for measuring the effects of toxicants on the behavior of groups of unmarked fish. Ctrax is an open source Python-based machine vision program that was originally designed to track fruit flies (Drosophila). The effects of the fish anaesthetic quinaldine sulfate on the behavior of groups of 10 unmarked Arabian killifish (Aphanias dispar) in a small arena were measured. Ctrax was able to identify and track the X-Y coordinates of the individual fish over 1 min recording periods. The data was analyzed using specifically written Matlab (The Mathworks™) toolboxes and the effects of quinaldine sulfate on absolute swimming velocity, forward swimming velocity, rate of change in orientation and distance to wall were calculated. Additionally the effects of quinaldine sulfate on path tortuosity were also measured. Ctrax has significant benefits over other available technologies for tracking the 2-dimensional coordinates of fish. In particular the software is open source and thus freely available, it is accurate, requires only simple easily available equipment and able to track potentially large groups of fish (possibly >50) while maintaining their individual identities.     

Use of Airborne Thermal Imagery to Detect and Monitor Inshore Oil Spill Residues During Darkness Hours

/ Trials were conducted using an airborne video system operating in the visible, near-infrared, and thermal wavelengths to detect two known oil spill releases during darkness at a distance of 10 nautical miles from the shore in St. Vincent's Gulf, South Australia. The oil spills consisted of two 20-liter samples released at 2-h intervals, one sample consisted of paraffinic neutral material and the other of automotive diesel oil. A tracking buoy was sent overboard in conjunction with the release of sample 1, and its movement monitored by satellite relay. Both oil residues were overflown by a light aircraft equipped with thermal, visible, and infrared imagers at a period of approximately 1 h after the release of the second oil residue. Trajectories of the oil residue releases were also modeled and the results compared to those obtained by the airborne video and the tracking buoy. Airborne imagery in the thermal wavelengths successfully located and mapped both oil residue samples during nighttime conditions. Results from the trial suggest that the most advantageous technique would be the combined use of the tracking beacon to obtain an approximate location of the oil spill and the airborne imagery to ascertain its extent and characteristics.KEY WORDS: Airborne video; Thermal imagery; Global positioning; Oil-spill monitoring; Tracking beacon     

Real-time fluorescent quantitative immuno-PCR method for determination of fluoranthene in water samples with a molecular beacon

A reliable and sensitive competitive real-time fluorescent quantitative immuno-PCR (RTFQ-IPCR) assay using a molecular beacon was developed for the determination of trace fluoranthene (FL) in the environment. Under optimized assay conditions, FL can be determined in the concentration range from 1 fg/mL to 100 ng/mL, with y = 0.194x + 7.859, and a correlation coe cient of 0.967 was identified, with a detection limit of 0.6 fg/mL. Environmental water samples were successfully analyzed, recovery was between 90% and 116%, with intra-day relative standard deviation (RSD) of 6.7%–12.8% and inter-day RSD of 8.4%–15.2%. The results obtained from RTFQ-IPCR were confirmed by ELISA, showing good accuracy and suitability to analyze FL in field samples. As a highly sensitive method, the molecular beacon-based RTFQ-IPCR is acceptable and promising for providing reliable test results to make environmental decisions.     

自动跟踪动压平衡烟尘采样仪的研制

ＧＭ１００Ｃ动压平衡自动跟踪烟尘采样仪,跟踪精度高,响应时间快,无需换孔板,只要拨动波段开关就可换采样嘴。     

基于分子信标探针的荧光定量PCR方法检测转基因食品

选择了内源基因大豆植物凝集素(lectin)、玉米转化酶(invertase)和外源基因花椰菜花叶病毒35S(CaMV35S)启动子的分子信标探针,确定了探针浓度和镁离子浓度等反应条件,分别对转基因大豆和转基因玉米系列标准品进行内源基因和外源基因的荧光PCR扩增,在PCR反应过程中分别以两种荧光通道信号分别追踪同一样品DNA内源基因和外源基因的扩增动力学变化,并依此绘制了循环阈值与转基因食品百分比含量之间的标准曲线,建立了转基因大豆和转基因玉米的分子信标探针-荧光定量PCR检测方法,该方法具有特异性强、敏感性高的特点,实现了对转基因食品的定量分析.图7表1参11     

Review on the study of mercury/silver ions-pyrimidine base pairs in DNA duplexes and their application in detection technology北大核心CSCD

Nucleic acids and their analogues are getting more and more attention. Metal-mediated base pairs as a kind of simple and functionalized nucleic acids in special positions have widened the scope of application of functional nucleic acids and their analogues. In this type of base pairs, the representative is the interaction between metal ions and pyrimidine bases, especially the research on thymine-Hg2+-thymine (T-Hg2+-T) and cytosine-Ag+-cytosine (C-Ag+-C) base pairs. This review summarizes the structure and mechanism of metal-mediate pyrimidine base pairs as well as the application in the biochemical analysis. It explores the mode and ratio of coordination between metal ions and base pairs, the effects on the stability of DNA helical structure, the related crystal structure and the three-dimensional configuration information in the DNA helix. The analytical application mainly includes various probes of metal ions, small molecules, protein and the detection of single nucleotide polymorphism. Among them the most widely used metal ions detection, and its combination with spectrum technology, visualization and amplification technology greatly promoted the rapid development of sensitive detection technology. In further studies, it is necessary to reveal the mechanism of interaction between T-Hg2+-T and C-Ag+-C, and more attention should be paid to combining of T-Hg2+-T and C-Ag+-C base pairs with other new technologies. The scope of practical application should also be further extended.