基于无人机数码影像的冬小麦氮含量反演

准确、快速地获取关键生育期冬小麦氮素含量,对农业管理者进行田间氮素施肥有重要的决策作用。利用无人机(unmannedaerialvehicle,UAV)搭载数码相机,可以短时间内获取冬小麦长势信息,实现对冬小麦氮素含量动态监测。该研究利用2015年北京市小汤山冬小麦无人机数码影像,采用3种阈值分割方法,将田间植株作物与土壤背景分离。对比影像分割方法的时效性与准确性,最终确定可见光波段差异植被指数VDVI(visible-band difference vegetation index)提取植被信息。按照试验方案要求,在不同的氮肥与水分胁迫管理下,将冬小麦3次重复试验分成48个试验小区,依据小区边界提取小区的红、绿和蓝通道的平均DN(digitalnumber)值,选取25个植被指数,同时与各个试验小区冬小麦不同器官氮含量进行相关性分析,筛选数码影像变量。由于植被指数之间耦合度较高,因此采用主成分分析对原始数据进行成分提取,提取特征向量参与建模,最后利用多元线性回归分析建立氮素反演模型,通过决定系数(R2)、均方根误差(RMSE)和归一化的均方根误差(nRMSE)3个指标筛选出最佳模型,探究各器官氮素含量与数码变量的相关性。结果表明,实验室实测氮素含量与UAV数码影像氮素反演结果及基本一致。在反演模型构建精度方面,3种数据处理结果整体部分植被指数,反演效果叶氮植株氮茎氮。以冬小麦挑旗期为例,叶片氮含量整体信息提取验证模型的R2、RMSE和nRMSE分别为0.85、0.235和6.10%,比部分信息提取验证模型的R2高0.14,RMSE和nRMSE分别降低0.068和1.77个百分点;比植被指数信息提取验证模型的R2高0.43,RMSE和nRMSE分别降低0.141和3.67个百分点。研究表明,基于UAV数码影像利用多元线性回归构建冬小麦氮素含量反演模型,对试验小区整体提取作物信息的方式反演冬小麦叶氮含量效果最好,相比传统反演方法,模型稳定性更高,可为冬小麦田间水肥决策管理提供参考。     

几种生长延缓剂对微型盆栽牡丹促成栽培的影响

以牡丹品种‘冠群芳’为试材,分别在促成栽培的萌动期、小风铃期、撒飘期采用多效唑（PP333）、丁酰肼（B9）、正丁醇和TIBA等4种植物生长延缓剂进行处理,研究其对牡丹生长及开花的影响。结果表明：3个时期比较,小风铃期施用生长延缓剂矮化效果优于混合芽萌动期,而撒飘期施用则易发生药害。4种延缓剂相比,正丁醇效果比PP333和B9好,尤其是25mg/kg正丁醇处理,花期提前2d,成花率高达100%,成花质量最好,花径达17.2cm,新枝、叶、叶柄的生长也受到明显抑制;施用TIBA对植株影响显著,但易发生药害。     

Physicochemical,Microbiological, and Sensory Properties of Pâté Elaborated from Whitemouth Croaker (Micropogonias furnieri) Muscle

The aim of this research was to formulate a unique product, croaker pâté, and to determine its physicochemical, microbiological, and sensorial characterization. Three formulations of pâté were elaborated. The pâtés fit in the stipulated regulations for the microbiological test. Regarding the texture, the pâtés presented a significant difference (p < 0.05) among each other. In the sensorial tests, the favorite pâté of the panel was formulation 3; in the acceptance test, it had higher levels of acceptance for color, flavor, and global acceptance in comparison with commercial pâté.     

An atypical Bacillus anthracis infection in a bull—A potential occupational health hazard

Bacillus anthracis infecting cattle is usually identified based on the typical symptom: sudden death. Bacillus anthracis causing atypical symptoms may remain undiagnosed and represent a potential occupational health hazard for, that is veterinarians and producers, butchers and tanners. In the year 2004, one case of sudden death in a dairy farm in southern Finland was diagnosed as bovine anthrax. Four years later 2008, an atypical case of anthrax was diagnosed in the same holding. The bull was taken to the Production Animal Hospital of the Faculty of Veterinary Medicine, University of Helsinki because of fever, loss of appetite and a symmetrically swollen scrotal sac. Penicillin treatment cured the fever but not the swollen scrotum. Before the intended therapeutic castration, a punctuate consisting of 10 ml fluid collected into a syringe from the scrotal sac was cultivated on blood agar at 37°C. After 24 hr, an almost pure culture of a completely non‐hemolytic Bacillus cereus‐like bacteria was obtained. The strain was identified as B. anthracis using Ba‐specific primers by the Finnish Food Safety Authority (RUOKAVIRASTO). After the diagnosis, the bull was euthanized and destroyed, the personnel were treated with prophylactic antibiotics and the clinic was disinfected. In this particular case, treatment with water, Virkon S and lime seemed to be effective to eliminate endospores and vegetative cells since no relapses of anthrax have occurred in 10 years. This case is the last reported anthrax case in Finland.     

海南红金龙芒果叶片营养规律研究

为了改善当前芒果生产技术的相对落后的局面,全面了解和掌握芒果的营养规律显得至关重要。通过对海南省三亚市红金龙芒果叶片中N、P、K、Ca、Mg、S、Fe、Mn、Cu、Zn、B等11种营养元素含量进行全年跟踪分析,较全面的得出红金龙芒果叶片的养分变化规律,可将红金龙芒果的生长周期分为4个阶段：营养生长期（5—9月）、生殖生长期（9—11月）、果实膨大期（11月—2月）和果实成熟期（2—4月）。各阶段叶片养分含量变化规律有所差异：营养生长期,叶片中营养元素除K含量有所下降之外,其余营养元素均有不同程度的升高;生殖生长期,叶片中的营养元素N、B、Ca含量上升,其他元素含量有不同程度的下降;果实膨大期,叶片中的N、K、Mn、Fe、Zn、B含量下降,Ca、Cu含量上升,P、S、Mg含量趋于平稳;果实成熟期,叶片中N、Mn、Fe、B、Cu含量均有不同程度增加,K、Ca、S、Zn含量有所降低;在整个生育期内,叶片中P、Mg、S、Zn等元素含量变化不大,呈锯齿状波动。本研究对于目前新的芒果栽培管理模式下营养诊断和养分综合管理都有重要的参考价值。     

亲水性包膜缓控释肥料的研制及其缓控释性能研究

以水性聚氨酯和水性丙烯酸的水溶液为包膜材料,添加粘结剂,采用流化床包涂的方法制备新型缓控释肥料。用扫描电镜研究了包膜肥料的截面形貌。用水浸泡法、土壤淋溶法研究肥料的包膜肥料的释放特性。     

水分胁迫对巴西香蕉幼苗叶片生理特性的影响

以巴西香蕉组培苗为试材,进行水分胁迫试验.结果表明,随着胁迫程度的加深,香蕉幼苗叶片的相对含水量、叶绿素a(Chla)、叶绿素b(Chlb)、总叶绿索和类胡萝卜素(Car)总体呈下降趋势,而叶片水分饱和亏缺、可溶性蛋白、可溶性糖和丙二醛(MDA)则呈增加趋势.综合不同处理下巴西香蕉幼苗水分特征和生理特征可知,香蕉幼苗对土壤水分的要求是田间持水量的71%～8%.     

A Survey of Horse Owner's Compliance with the Finnish Vaccination Program

Finnish Trotting and Breeding Association's electronic database (IT register) in Finland does not include vaccination entries of all horses. Especially, vaccination status of horses outside sport arenas is unclear. Objectives were to investigate vaccination practices of horse owners in Finland, to look for reasons associated with nonvaccination, and to evaluate the accuracy of the other statistics in Finland. The questionnaire study was executed. Horse owners (n = 1,198) told their vaccination practices, vaccinations used, and reasons for nonvaccination. Horses were mainly (85%–95%) vaccinated depending on the number of horses per horse owner. Equine influenza vaccine was mainly favored (94%). One reason for nonvaccination is that the horse is inactive in equine sport arenas (43%). Other reasons (53%) were age, horse does not take part in competitions but stay at home, and the owner decides that the horse does not need vaccination. Differences between age groups (young and old), competition types, and regions were not found by one-variable analysis, but vaccination status of horses outside equine sport arenas differed from horses active in competitions. By logistic regression analysis, it was indicated that purpose of use had influence on vaccination status. Reasons for nonvaccination surveyed in UK were confirmed. The control of the competition rules and possible sanctions exercised in competition venue are better explanatory factors than age, type of competition, and geographic home area. However, the risk to meet a nonvaccinated horse increases when going to the northern part of Finland.     

新疆厚皮甜瓜有机生态型无土栽培试验

通过有机生态型无土栽培技术解决设施甜瓜栽培中常发生的土壤酸化、返盐和土传病害等连作障碍问题。本试验选用4个新疆厚皮甜瓜品种采用有机型无土栽培,进行了基质的种类选择、配比、施肥、浇水等实验,探讨了新疆厚皮甜瓜有机生态型无土栽培管理技术措施。     

不同水培方式对草莓结果及果实品质的影响

以童子1号和赛娃2个草莓品种为材料,研究了桶式水培和管式水培2种水培方式下,3种浓度的营养液处理对草莓结果特性及果实品质的影响.试验结果表明,综合比较草莓的开花结果、果实大小、产量和果实品质指标,赛娃好于童子1号,桶式水培优于管式水培,童子1号在1.5倍剂量营养液处理下的表现优于其他浓度处理,赛娃在1.0倍剂量营养液浓...