基于时间序列塔里木河中游胡杨林春尺蠖危害的遥感监测

【目的】研究适用于塔里木河流域胡杨林春尺蠖危害中等尺度遥感监测方法。【方法】基于国产卫星HJ 星 CCD数据时间序列,构建监测模型,以塔里木胡杨国家级自然保护区为例,进行遥感病虫害监测研究。【结果】2017年3月下旬至4月上旬,胡杨林NDVI均值呈上升趋势,4月下旬至5月上旬呈明显下降,5月中旬后时,其NDVI再次上升;4月中旬至5月上旬,春尺蠖幼虫以3龄、4龄、5龄为主时,胡杨林被危害较为严重,其监测精度高达85%,但是,3月下旬至4月上旬,当春尺蠖幼虫以1龄、2龄为主时,胡杨被危害程度较轻,其监测精度较低为5%;研究区西侧轮台县胡杨林较先受到危害,东侧尉犁县胡杨后受到危害。【结论】我国HJ卫星,通过植被指数可有效评估塔里木河中游胡杨林受春尺蠖危害情况,当且仅当植被受害较为严重时其精度较高。4月中旬至5月上旬,春尺蠖幼虫以3龄、4龄、5龄为主时,是春尺蠖严重危害胡杨林的主要时期。由于研究区西侧轮台县春尺蠖发生较早,胡杨林较先受到危害,东侧尉犁县春尺蠖发生相对较晚,胡杨林后受到春尺蠖危害。     

基于遥感影像的县域冬小麦种植信息提取

冬小麦是陕西省关中地区重要的粮食作物。本研究以陕西省武功县为例,使用Landsat8 OLI影像作为数据源,综合使用NDVI阈值分割和决策树分类技术提取了武功县2017年冬小麦种植区域,并对各乡镇冬小麦种植面积和空间分布信息进行统计分析。结果表明：（1）在本研究区,冬小麦越冬期结合油菜开花期是利用遥感影像提取冬小麦种植信息的最佳时期组合;（2）运用NDVI阈值分割法结合决策树分类从OLI影像提取冬小麦种植面积的精度达到93%以上;（3）武功县2017年冬小麦种植面积为21 181.97 hm²,下辖各乡镇中长宁和贞元两镇冬小麦种植面积较大,分别占总面积的24%和19%;在县域尺度上,使用遥感技术提取的冬小麦种植面积和空间分布信息是准确可靠的。     

High resolution satellite imaging sensors for precision agriculture

The central concept of precision agriculture is to manage within-field soil and crop growth variability for more efficient use of farming inputs. Remote sensing has been an integral part of precision agriculture since the farming technology started developing in the mid to late 1980s. Various types of remote sensors carried on ground-based platforms, manned aircraft, satellites, and more recently, unmanned aircraft have been used for precision agriculture applications. Original satellite sensors, such as Landsat and SPOT, have commonly been used for agricultural applications over large geographic areas since the 1970s, but they have limited use for precision agriculture because of their relatively coarse spatial resolution and long revisit time. Recent developments in high resolution satellite sensors have significantly narrowed the gap in spatial resolution between satellite imagery and airborne imagery. Since the first high resolution satellite sensor IKONOS was launched in 1999, numerous commercial high resolution satellite sensors have become available. These imaging sensors not only provide images with high spatial resolution, but can also repeatedly view the same target area. The high revisit frequency and fast data turnaround time, combined with their relatively large aerial coverage, make high resolution satellite sensors attractive for many applications, including precision agriculture. This article will provide an overview of commercially available high resolution satellite sensors that have been used or have potential for precision agriculture. The applications of these sensors for precision agriculture are reviewed and application examples based on the studies conducted by the author and his collaborators are provided to illustrate how high resolution satellite imagery has been used for crop identification, crop yield variability mapping and pest management. Some challenges and future directions on the use of high resolution satellite sensors and other types of remote sensors for precision agriculture are discussed.     

基于沙培温室番茄生长特性确定水分传感器最佳埋设位置研究

为研究实时控制灌溉系统中温室番茄的沙地水分传感器合理埋设位置,将传感器距滴头水平距离与距滴头垂直距离结合后设定6个处理,不同生育期水分传感器设定不同的土壤含水量上下限,系统分析了沙培番茄生长、根系、光合参数、品质、WUE、产量等指标,结果表明：TDR土壤水分传感器埋设在沙地距滴灌带滴头垂直深度、水平距离均为10 cm处时较适宜。     

Insights into the virulence‐related genes of Edwardsiella tarda isolated from turbot in Europe: genetic homogeneity and evidence for vibrioferrin production

Edwardsiella tarda has long been known as a pathogen that causes severe economic losses in aquaculture industry. Insights gained on E. tarda pathogenesis may prove useful in the development of new methods for the treatment of infections as well as preventive measures against future outbreaks. In this report, we have established the correlation between the presence of virulence genes, related with three aspects typically involved in bacterial pathogenesis (chondroitinase activity, quorum sensing and siderophore‐mediated ferric uptake systems), in the genome of E. tarda strains isolated from turbot in Europe and their phenotypic traits. A total of 8 genes were tested by PCR for their presence in 73 E. tarda isolates. High homogeneity was observed in the presence/absence pattern of all the strains. Positive results in the amplification of virulence‐related genes were correlated with the detection of chondroitinase activity in agar plates, in vivo AHL production during fish infection and determination of type of siderophore produced by E. tarda. To the best of our knowledge, this is the first study carried out with European strains on potential virulence factors. Furthermore, we demonstrated for the first time that E. tarda produces the siderophore vibrioferrin.     

基于激光传感器的自动巡迹智能车控制系统

本智能小车控制系统以MC9S12G128控制器为核心,利用一排18个激光发射管与6个接收管作为路径识别传感器,通过MC9S12G128的I/O口获得传感器信号,并利用特征提取方法提取赛道类型,实现起跑线、十字交叉线识别。根据道路信息,采用模糊控制算法输出PWM波形来控制舵机的转向,完成对小车的方向上的控制,采用光电编码器提取小车速度,经过与当前设定值进行比较得到速度偏差,采用PID算法计算并输出PWM脉冲来控制电机调节小车速度,完成对小车运动速度的闭环控制。实验验证,该系统达到了预期设计效果。     

假单胞菌HT66的PhzI-PhzR调控系统的功能研究

绿针假单胞菌(Pseudomonas chlororaphis)HT66是一株分泌高水平吩嗪-1-甲酰胺(phenazine-1-carboxamide,简称PCN)的植物根际促生细菌。通过全基因组测序与分析,发现phz基因簇上游存在着PhzI-PhzR双元调控系统。显色实验表明,野生株信号分子抽提物不能使指示菌紫色杆菌(Chromobacterium violaceum)CV026显紫色,但能使指示菌根癌农杆菌(Agrobacterium tumefaciens)NTL4显蓝色。研究采用基因无痕敲除方法构建了突变株ΔphzⅠ、ΔphzR;与野生株相比,ΔphzⅠ突变株丧失了PCN合成能力,对终极腐霉的抑制作用明显下降;而且突变株ΔphzⅠ的信号分子抽提物也不能使指示菌NTL4菌显色。由此可见,菌株HT66以高丝氨酸内酯作为群体感应的信号分子,且吩嗪的生物合成受到了PhzI-PhzR的严格调控。进一步形态观察表明,突变株ΔphzⅠ的菌落颜色变为乳白色,鞭毛泳动性与野生株相比大大降低,但其群体从动性变化不显著。     

基于三网融合下的农民远程培训平台的构建与实现

随着科技的不断进步,现代农业信息化服务方式由单一化逐渐向多元化方向发展。本文基于三网融合形势下,构建农民远程培训平台,通过科教视频、手机推送、远程培训、视频咨询诊断等方式,向农民提供灵活多样的农技服务。     

Information fusion in aquaculture: a state-of the art review

Efficient fish feeding is currently one of biggest challenges in aquaculture to enhance the production of fish quality and quantity. In this review, an information fusion approach was used to integrate multi-sensor and computer vision techniques to make fish feeding more efficient and accurate. Information fusion is a well-known technology that has been used in different fields of artificial intelligence, robotics, image processing, computer vision, sensors and wireless sensor networks. Information fusion in aquaculture is a growing field of research that is used to enhance the performance of an “industrialized” ecosystem. This review study surveys different fish feeding systems using multi-sensor data fusion, computer vision technology, and different food intake models. In addition, different fish behavior monitoring techniques are discussed, and the parameters of water, pH, dissolved oxygen, turbidity, temperature etc., necessary for the fish feeding process, are examined. Moreover, the different waste management and fish disease diagnosis techniques using different technologies, expert systems and modeling are also reviewed.     

水稻病原菌Burkholderia plantarii群体感应和群体淬灭研究进展

植物伯克霍尔德菌Burkholderia plantarii是引起水稻秧苗细菌性立枯病的重要病原菌之一,其侵染性、繁殖力及适应性均很强,严重威胁中国水稻生产。文章围绕B.plantarii的发生、危害及致病机理,着重论述了细菌群体感应系统(quorum sensing,QS)的生理功能及其在B.plantarii致病力调控方面的最新研究进展,并进一步从根际微生物互作角度,综述了种间信号分子对病原菌群体淬灭(quorum quenching)的作用机制,同时结合种间信号分子的独特性,展望了其在新型微生物杀菌剂研发中的重要性和应用潜力。