利用萝卜漂浮育苗及蜂蚜同接法快速扩繁烟蚜茧蜂效果研究

为解决南雄烟区春季低温条件下,使用烟苗漂浮育苗法扩繁烟蚜及烟蚜茧蜂繁过程中寄主繁育速度慢的问题,开展了利用漂浮育苗法繁育萝卜苗,采用蜂蚜同接法在萝卜苗上繁殖烟蚜茧蜂的试验。结果表明,漂浮萝卜苗生长至5 叶1 心需要24.5 天,比漂浮烟苗生长至5 叶1 心缩短了25 天。在漂浮萝卜苗生长至3 叶1 心时以蜂蚜同接法每株分别接蚜15~20头繁蜂效果较好,20天后每株僵蚜量最高可达125.5 头,25 天后每株僵蚜量最高可达145.5 头。每株接蚜30 头,可以在20 天后得到最大僵蚜产量152.5头,但25天时僵蚜数量出现下降趋势。利用漂浮苗育法繁育萝卜寄主,在萝卜苗生长至3叶1心或4叶1心时,采用含40%寄生蚜的蜂蚜同接法扩繁烟蚜茧蜂,可获得较高繁蜂效果,并使整个繁蜂过程时间缩短20~25天左右,简化了繁蜂工艺,降低了繁蜂成本。     

A comparison between decay patterns of the white‐rot fungus Pleurotus ostreatus in chestnut–leaved oak (Quercus castaneifolia) shows predominantly simultaneous attack both in vivo and in vitro

In this research, we examined decay patterns occurring in Quercus castaneifolia wood under natural conditions compared with controlled decay in vivo. Pleurotus ostreatus‐infected oak wood was obtained from the Sari forests in the north of Iran. The species causing decay was verified as P. ostreatus using rDNA‐ITS sequencing of pure cultures from infected sapwood. In addition to P. ostreatus, two wood‐inhabiting Ascomycota, Trichoderma harzianum and T. lixii, were present. Mass loss in oak sapwood samples exposed to P. ostreatus for 60 days was around 10 per cent. Samples were prepared from both naturally decayed wood and wood decayed under controlled conditions and examined using microscopy. P. ostreatus was found to produce a simultaneous white‐rot decay pattern in both conditions.     

鸡粪中氨减释菌的筛选及应用效果

鸡粪中有大量的含氮有机物,这些含氮有机物在微生物的分解代谢活动下会释放出氨气,氨气挥发不仅污染环境,同时也是一种氮素的浪费。以减少氨气释放量、保持粪便肥效为目的,从鸡粪中分离获得1株可快速转化氨氮的细菌,命名为YX3。VITEK系统鉴定表明,菌株YX3与鲍曼不动杆菌的相似度为99%,并结合菌株的形态特征、生理生化特性,初步鉴定菌株YX3属于鲍曼不动杆菌,该菌株不产硫化氢、不进行反硝化。扩散皿试验表明,与对照相比,菌株YX3对降低氨气释放具有明显且稳定的效果,其氨减释率为81.11%。在以(NH_4)_2SO_4为氮源时,菌株YX3在48 h内将培养基中84.65%的氨氮转化为硝酸盐氮。菌株YX3在以蛋白胨为氮源时,可将蛋白胨分解产生的氨氮迅速转化为硝酸盐氮,最终培养液中有133.72 mg/L硝酸盐氮的积累。与对照相比,菌株YX3在鸡粪模拟试验中氨气挥发下降84.46%,且氨减释效果保持时间较长。以上研究结果说明,菌株YX3在减少氨气挥发、为畜禽生长提供良好环境、降低畜禽废弃物中氮素损失及保持粪便肥效等方面有较好的应用潜力。     

移动机器人RGB-D视觉SLAM算法

针对移动机器人视觉同步定位以及地图构建(Simultaneous localization and mapping,SLAM)研究中存在精确度较低、实时性较差等问题,提出了一种用于移动机器人的RGB-D视觉SLAM算法。首先利用定向二进制简单描述符(Oriented fast and rotated brief,ORB)算法提取RGB图像的特征点,通过基于快速近似最邻近(Fast library for approximate nearest neighbors,FLANN)的双向邻近(K-nearest neighbor,KNN)特征匹配方法得到匹配点对集合,利用改进后的随机抽样一致性(Re-estimate random sample consensus,RE-RANSAC)算法剔除误匹配点,估计得到相邻图像间的6D运动变换模型,然后利用广义迭代最近点(Generalized iterative closest point,GICP)算法得到优化后的运动变换模型,进而求解得到相机位姿。为提高定位精度,引入随机闭环检测环节,减少了机器人定位过程中的累积误差,并采用全局图优化(General graph optimization,G2O)方法对相机位姿图进行优化,得到全局最优相机位姿和相机运动轨迹;最终通过点云拼接生成全局彩色稠密点云地图。针对所测试的FR1数据集,本文算法的最小定位误差为0.011 m,平均定位误差为0.024 5 m,每帧数据平均处理时间为0.032 s,满足移动机器人快速定位建图的需求。     

关于联立Pell方程组x2-D1y2=-1和z2-D2y2=-1

设D1,D2是正奇数,D2-D1=22r 1d,其中r是非负整数,d是正奇数.如果r＜2,则方程组x2-D1y2=-1和z2-D2y2=-1无正整数解(x,y,z).     

气候敏感的马尾松生物量相容性方程系统研建

【目的】构建气候敏感的马尾松生物量相容性方程系统,分析气候因子对马尾松各分项生物量的影响,为森林碳汇监测和森林可持续经营提供技术支撑。【方法】基于150株马尾松单木生物量数据,采用非线性联立方程组法构建气候敏感的马尾松生物量相容性方程系统,各分项生物量(干材、干皮、树枝、树叶和地上总生物量)选用以直径和树高为自变量的二元生物量方程作为基础模型,利用一阶交叉验证法对所构建的生物量相容性方程系统进行评价。【结果】与传统未考虑气候因子的各分项生物量模型相比,气候敏感的马尾松生物量相容性方程系统预测精度明显提高,且该生物量相容性方程系统可定量描述不同气候带亚区生物量的差异程度,保证干材、干皮、树枝和树叶与地上总生物量相容。【结论】气候敏感的马尾松生物量相容性方程系统能有效分析气候因子对各分项生物量的影响,可应用于其他树种的生物量预估。     

A universal probe for simultaneous detection of six pospiviroids and natural infection of potato spindle tuber viroid (PSTVd) in tomato in China

Several viroids in the genus Pospiviroid can infect tomato (Solanum lycopersicum) and cause severe diseases, posing a serious threat to tomato production.  For simultaneous detection of six tomato-infecting pospiviroids - columnea latent viroid (CLVd), pepper chat fruit viroid (PCFVd), potato spindle tuber viroid (PSTVd), tomato apical stunt viroid (TASVd), tomato chlorotic dwarf viroid (TCDVd), and tomato planta macho viroid (TPMVd), we developed a universal probe based on a highly conserved 61 nt long sequence shared among them.  Compared with their specific probes, the universal probe has a similar, though slightly reduced, detection sensitivity and has the advantages of simple and cost-effective preparation and simultaneous detection of the six pospiviroids.  In addition, the universal probe was used in dot-blot hybridization assays for a large-scale survey of viroid(s) in tomato plantings in China.  Only PSTVd was detected in a few greenhouse-planted tomato plants.  Sequence analysis revealed that these tomato PSTVd isolates may have been introduced from tomato seeds imported from abroad.      

同步检测为害百合种球3种检疫性病毒的多重RT-PCR方法

 The multiplex RT-PCR approach was developed for simultaneous detections of Arabis mosaic virus(ArMV),Strawberry latent ringspot virus(SLRSV)and Lily symptomless virus(LSV)from the imported lily bulbs.The results indicated that good specificity and sensitivity for simultaneous detection were obtained.The ultimate of RNA detection with three viruses mixture was 305 pg.The ultimate of RNA detection with ArMV,SLRSV and LSV were 156.0,13.4 pg and 1.12 ng respectively.This approach has potential to be used in quarantine of imports and exports.     

基于单目视觉的动态环境同步定位与多地图构建算法

针对传统V-SLAM算法是在假设场景刚性不变的条件下进行建图,导致无法实现动态环境建图,以及传统算法无法克服因环境特征不明显或机器人被“绑架劫持”而导致场景跟丢的问题,提出一种在动态环境下同步定位与多地图构建(DE-SLAMM)算法。该算法首先引入一种多地图构建思想,当跟踪失败时会自适应生成一个新的局部地图,并在回环时将该地图与之前地图融合,解决算法跟丢后无法建图的问题。其次,结合深度学习和多视图几何技术实现对环境中的动态物体进行实时检测,并利用多帧融合技术对动态对象遮挡的部分进行背景修复,有效解决动态环境下跟踪建图问题。最后将该算法应用于实际场景进行测试,结果表明,相比经典的V-SLAM算法(ORB-SLAM2、ORBSLAMM和DynaSLAM),当发生跟踪丢失时,本文算法在很短时间内快速重建地图并实现继续跟踪和新地图融合,而ORB-SLAM2和DynaSLAM跟丢后进入重定位模式,无法继续建图;ORBSLAMM跟丢后虽然可以继续建图,但其建立的地图不能实现多地图融合,无法构建整体地图;进一步通过动态环境测试实验发现,只有本文算法可实现所有动态目标(先验和移动目标)的实时检测及背景...     

Fuel ethanol preparation from straw stalks usingsimultaneous saccharification and fermentation 

The effects of temperature, time, inoculating quantity and dosage of cellulose enzyme on the preparation of fuel ethanol from straw stalks by means of the simultaneous saccharification and fermentation method (SSF) were studied. The results show that after pretreating straw stalk by mechanical comminution and sparse sulfuric acid, the optimal fermenting temperature is 38 ℃, the fermenting period is 72 h, the inoculating quantity is 10%, the dosage of cellulose enzyme is 40 IU/g, and the ratio of Pachysolen tannophilu to saccharomyces cerevisiae is 2∶1. The ethanol yield reaches as high as 0.20 g/g.