蹄耕法改良山地退化草地技术应用研究

采用人工撒播、羊喂播,牛、羊背播等方法结合家畜放牧蹄耕技术,在新疆坡度较大无法进行机械作业的山地退化草地进行补播改良,试验结果表明:放牧蹄耕法技术改良最适宜的草地类型为山地草甸草原。最佳补播时期为早春播种,最适合牧草品种为红豆草;最好的补播方法为人工撒播,最适宜坡度为20°为好。通过蹄耕法改良后,草地植被覆盖度在原有的基础上最高提高了35%,优质牧草比重增加了25%,鲜草产量提高了3~4倍。     

蜡样芽孢杆菌芽孢萌发及其对常规灭菌方法抵抗力的研究简

芽孢杆菌属细菌在芽孢状态下,对外界环境及理化因素具有高度抵抗力。适宜的温度、湿度及营养条件能促进芽孢萌发,影响其对常规灭菌方法的抵抗力。本试验选取蜡样芽孢杆菌作为研究对象,在适宜培养条件下使其形成芽孢,通过研究萌发后芽孢对温度、H₂O₂及含氯消毒剂等条件的抵抗力,证实了适当的条件（温度37 ℃、湿度40%、pH 7.4、30 min）能有效促进蜡样芽孢杆菌芽孢萌发,致使芽孢对高温（80 ℃、2 h）、H₂O₂（1.5 mol/L、2 h）及含氯消毒剂（有效氯含量约800 mg/L、2 h）等常规灭菌方法抵抗力明显降低,并能被有效杀灭和灭活,相对有效杀灭率分别达98.4%、98.9%及99.1%,有效杀灭率分别为88.3%、88.7%及88.9%,这对进一步研究芽孢杆菌属细菌的杀菌消毒条件具有重要参考意义。     

应用DPO-PCR方法特异性检测志贺氏菌

In this study, a dual-priming oligonucleotide (DPO)-based PCR method for specific detection of Shigella was established using ipaH gene of Shigella as the target gene. The results showed that detection sensitivity of the DPO-PCR method was 1.65×10² CFU/mL. Compared with conventional PCR primers, the DPO primers were easily designed, which simplified the design procedure of PCR primers. DPO primers were not sensitive to annealing temperature, which could efficiently amplify the target gene in the annealing temperature range from 50 to 70 ℃. Moreover, due to the special structure of DPO primers, it had a higher specificity than conventional PCR primers, and none nonspecific amplifications were produced in reaction. In the practical application, tests on 133 samples including frozen/fresh meat, fruits and vegetables, fresh milk, eggs and cooked food by the DPO-PCR method showed that 15 samples were Shigella positive, which were in accordance with the testing results using GB method (GB/T 4789.5-2012), showing good practicality and reliability. The DPO-PCR method provided a new tool for fast and accurate detection of Shigella.     

《动物寄生虫》课程考核方式的改革探讨

为了全方面地进行课程改革,使课程改革取得更好的效果,金华职业技术学院主要从理论考核、实践考核以及结合适当的论文写作等三方面入手,针对《动物寄生虫》课程考核方式的改革进行了探讨,以期更好地服务于课程全面改革的实践。     

动物解剖学多媒体技术和传统教学方法的实践应用

动物解剖学作为传统的动物医学基础课,其内容较为枯燥单调,在长期的教学建设中,如何对动物解剖学的教学方法进行改革等问题,一直困扰着动物解剖教学工作者。中国农业大学动物医学院的教师们在动物解剖学教学过程中,将传统的教学方式和多媒体技术很好地结合起来,并进行了积极的探索与实践,取得了良好的教学效果。     

Estimation of gillnet selectivity curve by maximum likelihood method

ABSTRACT: A maximum likelihood method of estimating gillnet selectivity when data are obtained by gillnet fleets consisting of several nets of differing mesh size is presented in this paper. The SELECT model is expanded by application of the relative length (i.e. the ratio of fish length to mesh size) to obtain a master curve of gillnet selectivity. Four kinds of functional model, normal, lognormal, skew-normal and bi-normal are fitted to the data. In addition, two cases in which the relative fishing intensity is either estimated or fixed by catch effort are compared. The bi-normal model has the lower model deviance regardless of whether the relative fishing intensity is estimated or not. The estimation of relative fishing intensity by catch effort is also examined in which the estimates of the parameter of the SELECT model are compared with the catch effort as determined by the number of nets of each mesh size used. For the bi-normal model these quantities compare well. Thus, it is concluded that this method gives reliable estimates even if data for each mesh size is obtained with different catch efforts.     

苹果汁品质评价方法研究进展

苹果汁是我国苹果产业的主要加工产品,因其营养丰富、风味独特受到广大消费者的喜爱,准确快速评价苹果汁品质对苹果汁的加工、储藏、流通和贸易具有重要指导意义。本文对不同的苹果汁产品的感官评价语言与方法进行了综述,分析了加工品质指标、感官品质指标和理化与营养品质指标的仪器测定方法与最新研究进展,品质评价指标筛选方法及综合评价方法,以期为不同苹果汁产品评价体系的建立提供参考。     

Residential runoff – The role of spatial density and surface cover,with a case study in the Höjeå river catchment,southern Sweden

Depending on the spatial density of built cover and location within a catchment, residential areas make varying contributions to surface runoff throughout different rainfall events. This study examined these contributions and the associated effect of different surface covers and sustainable drainage systems on runoff generation. The Soil Conservation Service curve number (SCS-CN) method was applied to analyse urban development in the Höjeå river catchment in southern Sweden.The results indicated that identical amounts of surface runoff are generated by low-density residential areas on heavy clay soils and high-density residential areas on sandy soils. However, increasing the density of built-up areas on sandy soils is likely to be more disruptive to the hydrological balance and to generate a greatly increasing difference in runoff as building density and impermeable surface area increase. A similar pattern is likely to occur if rainfall intensity increases. It may therefore be appropriate to apply different planning considerations to residential developments depending on the existing soil group, e.g. conserving existing vegetated surfaces on sandy soil and incorporating permeable paving materials and sub-surface infiltration beds in development on clayey soils. Increased area of impermeable surface cover will increase surface runoff in all residential areas, irrespective of building density, soil group and rainfall intensity. However, adapting a systems approach in combining vegetative structures and permeable paving materials with subsurface infiltration beds can help mitigate the impact of surface runoff, particularly in urban developments on clay-rich soils.     

淡水养殖梭鱼的人工繁殖机理

1982～1986年;作者采用外源药理学方法,使淡水养殖梭鱼(S‰0.297-0.569)克服了“淡水不育症”,雌鱼性腺成熟率85％以上,完全取代了“海水过渡”。在人工催产中又克服了排卵机制的障碍及胚胎对环境的不适应,并对梭鱼亲鱼血清激素含量进行放射免疫(RIA)测定及电子显微镜对梭鱼脑垂体亚显微结构进行观察。提出梭鱼存在血脑屏障。