Microsatellite DNA analysis and hydrodynamic modelling reveal the extent of larval transport and gene flow between management zones in an exploited marine fish (Glaucosoma hebraicum)

Determining the extent of dispersal in exploited marine fishes is essential for understanding their population dynamics and optimising management. The West Australian dhufish, Glaucosoma hebraicum, is a highly sought‐after, large and long‐lived reef‐dwelling species, endemic to south‐western Australia. Stock assessments indicate that this indicator species is overexploited. The fishery is managed using a zone‐based system, which implicitly assumes a high degree of demographic independence among zones. While tagging studies indicate limited movement of adult G. hebraicum, there is no understanding of the spatial scale of dispersal of its larvae and thus the true extent of interdependence of management zones. We analysed 13 microsatellite DNA loci to characterise the extent of gene flow, and conducted particle tracking simulations to model larval transport in this species. Genetic data demonstrated that some local recruitment was likely, but that on a broad scale gene flow between the management zones was extensive, and the entire fishery represents a single genetic stock. Hydrodynamic modelling predicted that the majority of dhufish larvae recruit from within the management zone where they are spawned, and that inter‐annual variation in current velocities has limited effect on the extent of larval transport. Because management zones are likely to be largely independent in terms of both larval and adult recruitment, heavy localised fishing pressure has the potential to reduce the abundance and reproductive capacity of this species in highly fished areas, but it should have limited impact on neutral genetic diversity.     

农牧区离网型风力发电系统控制策略

[目的]研究农牧区离网型风力发电系统控制策略。[方法]根据离网型风力机的运行特性,采用负载跟踪和充放电集成控制的系统结构,研究了不同工作状况对风力发电系统运行的影响。[结果]提取出系统的工作模式及工作模式之间的转换关系,给出了实现系统模式相应的控制策略。[结论]负载跟踪和充放电集成控制方法有利于实现离网型风力发电系统的优化及可靠运行。     

基于DSP的太阳能跟踪控制系统研究

针对目前太阳能跟踪系统存在的跟踪精度不高,抗干扰能力差的缺点。设计一种以视日运动轨迹跟踪和光电检测跟踪相结合的控制方法对太阳能进行跟踪,并且以DSP为控制器核心芯片的高精度太阳能智能跟踪系统。视日运动轨迹跟踪对太阳进行粗跟踪,再利用光电检测跟踪对太阳进行精确跟踪。实现对太阳的高精度跟踪,并且使系统具有较强的抗干扰和运算能力。     

Performance analysis on improved PDA AI for moving target tracking

Aim at the problem that the EO imaging tracking system is inconsistent with the model of probabilistic data association with amplitude information (PDA AI), which supposes that the greater the amplitude value is, the greater the probability of being the tracked target will be, a modified PDA AI (MPDA AI) is presented . Based on the fact that the amplitude and the motion of the interested target are consistent in a short period, the MPDA AI models the amplitude information and the motion information of the target as well as their consistency with Markov stationary signal to analyze the association procedure of motion and amplitude. The lower bounds of Cramer Rao estimation error for PDA AI and MPDA AI are calculated and discussed in detail. The theoretical analysis and experimental results show that estimating the target motion with the MPDA AI will be more accurate and more reliable than estimating with the original PDA AI.     

信阳市园林植物真菌性病害调查与鉴定（Ⅱ）

对信阳市11种园林植物的真菌性病害进行了病害调查及病原鉴定,对病害病状及病原菌的形态进行了观察和研究,结果发现病害12种。其中,杜英叶斑病、龙爪槐炭疽病及海桐叶斑病为河南省3种新记录病害。分布较广、为害较严重的病害有紫荆角斑病、樱花褐斑病、枇杷叶斑病、龙爪槐炭疽病、鸢尾褐斑病、鸡冠花叶斑病6种病害。     

患病罗汉鱼疑似病原菌分离鉴定与药敏试验

[目的]分离鉴定患病罗汉鱼疑似病原菌,并进行药敏试验。[方法]对患病罗汉鱼进行体表、口腔、鳃、肾、肝、肠等器官及肌肉组织的病理变化观察。在病灶（下颌）、肾、肝、鳃处分离细菌,并对分离的细菌进行初步鉴定和药敏试验。[结果]在病灶（下颌）、肾、肝、鳃处分离出3株优势细菌。通过菌落形态观察以及生理生化测定,鉴定出该3株细菌分别为嗜水气单胞菌（Aeromonas hydrophila）、假单胞菌（Pseudomonas sp.）、链球菌（Streptococcus sp.）,适宜盐度分别为：10.00‰~20.00‰0、.01‰~1.00‰、0.01‰~1.00‰,对四环素、红霉素、土霉素等药物高度敏感。[结论]为找到预防与治疗罗汉鱼疾病的有效手段提供了科学依据,同时也为其他观赏鱼细菌性疾病的防治提供参考和借鉴。     

视觉导引AGV鲁棒特征识别与精确路径跟踪研究

针对AGV多分支路径与工位点标识的可靠识别以及导引路径的精确跟踪问题,提出了一种基于双视野窗口的鲁棒特征识别与精确路径跟踪方法。采用整幅视野范围作为模式识别窗口,在该窗口采用基于核主成分分析(KPCA)和BP神经网络的识别方法,将路径特征通过核函数映射到高维空间进行PCA降维,再利用BP神经网络识别降维后的样本矩阵。同时提出一种导引扫描窗口设置方法,该窗口范围取决于摄像机竖直视角以及摄像机安装倾斜角,在导引扫描窗口内将导引路径简化为直线模型并用最小二乘法拟合,针对拟合直线计算导引所需的路径偏差。实验结果表明,KPCA-BP方法显著提高了路径特征识别的实时性和鲁棒性,6类路径特征的平均特征识别正确率为99.5%;导引扫描窗口有效减小了导引路径直线拟合的计算误差,直线路径跟踪误差小于3 mm,曲线路径跟踪误差小于30 mm。     

基于双切圆寻线模型的农机导航控制方法

针对油菜直播机组导航作业中田头换行、转弯等直线跟踪之间的衔接控制问题,设计了一种适用于2BFQ-6型油菜精量联合直播机导航的双切圆寻线模型控制方法。对初始偏差较大时拖拉机的寻线路径进行了定量分析,获得最优寻线路径的几何关系,依据该关系构建控制决策方法。所建决策方法根据拖拉机位姿状态选择相匹配的控制方程组,计算获得前轮转角以实现导航控制。进行了双切圆寻线模型参数仿真优化和性能与适应性仿真试验。使用该模型控制器进行拖拉机路面导航试验,结果表明:当行驶速度为0.7 m/s,拖拉机与目标直线初始横向偏差为7 m,初始航向偏角为90°时,控制器横向偏差响应的超调量不超过3%,上升时间小于14 s,调节时间不大于19 s,较纯追踪模型方法的超调量和调节时间更小;田间和路面试验结果表明:该模型控制方法对2BFQ-6型油菜精量联合直播机导航作业过程中的对行播种起始位姿调整和套行作业自动转弯操作具有指导价值。     

履带式拖拉机自动驾驶系统路径智能跟踪控制研究

为实现复杂环境下履带式拖拉机田间作业的路径跟踪控制,设计了履带式拖拉机自动驾驶系统,并对路径跟踪与控制算法进行了研究。自动驾驶系统由MCU、双源激光定位系统、速度控制系统、点火/熄火控制系统、液压转向系统等组成。采用模糊算法对行驶过程中的路径偏差进行补偿,实现对路径的跟踪控制。为验证算法的有效性,进行了Matlab/Simulate仿真与田间试验。结果显示对于NF502型履带拖拉机,该系统在100 m范围内可实现有效控制,表明该算法能实现对行驶路线跟踪与控制。     

基于ASTUKF的分布式农业车辆路面参数辨识方法

针对分布式驱动农业车辆在路面参数辨识过程中,因路面环境变化出现的状态模型误差和时变噪声,导致辨识结果发散的问题,提出了基于自适应强跟踪无迹卡尔曼滤波(Adaptive strong tracking unscented Kalman filter, ASTUKF)的辨识方法。与传统内燃机农业车辆相比,分布式驱动可以直接获取驱动轮的状态信息,结合含有峰值附着系数和极限滑转率的μ-s曲线模型,建立了无迹卡尔曼滤波(Unscented Kalman filter, UKF)辨识算法的状态方程和量测方程。同时,将强跟踪滤波(Strong tracking filter, STF)和自适应滤波(Adaptive filter, AF)引入辨识算法,用以提高对多变环境的识别精度和鲁棒性,并采用奇异值分解(Singular value decomposition, SVD)解决了迭代过程中出现的非正定矩阵的问题。仿真试验结果表明,在突变噪声环境工况下,ASTUKF辨识结果可以快速收敛至目标值附近,且不受突变噪声的影响,各驱动轮峰值附着系数估计结果的平均绝对误差(Mean absolute error...