Immunopathology of the eye: Purification of canine retinal “S” antigen

Canine retinal S antigen has been purified to study the retinal progressive atrophy of the dog. The purified antigen will be used to detect, by the ELISA technique, specific autoantibody in dogs with ocular diseases.     

新西兰白兔胃底腺等器官生后发育及超微结构变化的研究

通过组织学及电镜技术对新西兰白兔胃底腺、小肠绒毛及肠腺的发育进行了，结果表明：新西兰白兔胃底腺、肠腺和肠绒毛的生长表现出明显的阶段性，胃底腺高度生长的最快阶段约在初生至１周龄及２－６周龄，小肠绒毛高度、宽度及表面生长的最快阶段约在初生至１周龄及３－６周龄，肠腺高度生长的最快阶段与小肠绒毛的高度生长基本。     

Wear of spring tine cultivator points in sandy loam and light clay soils in southern Poland

Correct evaluation and forecasting of durability of soil cutting parts are the decisive factors for proper operation of agricultural machinery. During operation of cultivators, over two-fold difference in wear of cultivator points is observed, which makes establishing of their exchange periods extremely difficult. So, there is a need to conduct some research aimed for determination of relationship between arrangement of the points in individual cultivator rows and their wear. The presented experiments were performed under authentic farm conditions during spring soil loosening and levelling operations before sowing and planting, in sandy loam and light clay soils. Changes in length and thickness of the spring tine points, wear patterns and weight loss were measured. Loss in length of spring tine points was described by a complex function of the distance travelled or by an exponential function of the distance from the measuring point to the symmetry axis of a spring tine point; loss in thickness was described by a linear function. It was found that soil type, as well as arrangement of the points in individual cultivator rows and their position in relation to the tractor wheel track, significantly influenced their wear. It was also observed that wear of spring tine points was 40–100% higher in the sandy loam soil than in the light clay soil, and that wear within a tractor wheel track was 17–40% higher than outside the track. Moreover, wear of points positioned in the first row on the cultivator frame was 26–100% higher than wear of those in the third row. The research results emphasise the need for field experiments at compare wear of spring tine points made of different materials or of different designs to take into account differences in wear due to positioning of the points on cultivator frames.     

The effectiveness of cultivation using the winged time on restored sand and gravel workings

A study to examine the effectiveness and longevity of ‘deep’ ripping using a winged time on restored sand and gravel workings is described. Measurements of soil bulk density, penetration resistance and microtopography were used to monitor the effects on the soil over a 5 year period. Ripping to 0.45 and 0.6 m depth produced loosened soil to a maximum depth of about 0.4 m, but recompaction occurred rapidly, especially in the first year after ripping. The need to prevent soil compaction is emphasised. Ripping has only a limited ability to remedy soil physical degradation caused by machine-induced compaction. Trees planted on land restored using the winged tine are likely to suffer from moisture stress and wind instability as they mature.     

土壤耕作部件极窄刀齿与土壤作用关系研究

随着保护性耕作技术和低扰动土壤处理技术的发展,新型土壤耕作部件越来越多地采用窄类或极窄类刀齿形式。通过理论分析和室内土槽试验,对矩形齿和三角形齿两种极窄刀齿贯入土壤造成的土壤失效机理、刀齿工作时的主要阻力来源、刀齿形状尺寸参数对贯入阻力的影响以及刀齿贯入阻力预测模型进行了研究。结果发现,极窄刀齿在贯入土壤过程中,土壤与刀齿相互作用产生应力场和速度场,土壤主要受到刀齿的挤压而失效;刀齿所受阻力可以通过相互作用过程中产生的力学分量进行预测,特别是该预测模型能够较好地反映刀齿在不同深度下所受阻力的变化趋势,研究还发现在土壤参数一定的情况下,极窄刀齿所受阻力与刀齿和土壤的接触面积直接相关,极窄刀齿的形状尺寸参数是其受力的重要影响因素。     

我国森林植物检疫工作的历史回顾

该文对我国森林植物检疫法规、机构、执法队伍的建设和森检科技的发展进行了回顾和总结，并就森林植物检疫工作在森林资源和生态环境保护中的作用进行了客观的评价。     

后贝加尔湖春小麦栽培的某些特点

本文研究后贝加尔湖春小麦栽培的最适播种期和施用无机肥的配方。研究结果表明:该地区春小麦中熟品种最适宜的播种期是4月末到5月上旬;最佳施肥量及配方为N_(60)P_(60)K_(40)。     

高产优质玉米杂交种黔原三号的选育

利用核辐射诱变育成的黔辐49突变体系，是配合力强、抗病性好、产量较高、综合性状好的玉米优良自交系，与木6自交系组配杂交，育成黔原三号优良杂交种。     

深松铲铲尖对土壤扰动过程及效果的试验与分析

铲尖是深松铲的关键部件之一,其对土壤扰动产生重要影响。在分析铲尖对土壤扰动过程及影响机理的基础上,以凿形铲、箭形铲、翼形铲为对象,用碎土率、土壤蓬松度、土壤扰动系数、地表平整度等评价指标,并用高速摄影技术进一步研究不同铲尖形状对土壤扰动过程及效果的影响。结果表明:(1)铲尖形状对土壤扰动过程产生重要影响,翼形铲作业形成垄沟的地表宽度及沟底宽度最大,箭形铲次之、凿形铲最小;(2)随深松铲铲尖与土壤接触面积及土块间的二次接触概率的增加,土壤破碎效果不断改善,采用凿形铲、箭形铲、翼形铲深松后,10cm耕层的碎土率分别为89.29%、90.87%、94.75%,全耕层的碎土率分别为85.09%、92.23%、96.13%;(3)铲尖形状是影响土壤疏松程度和地表平整性的重要因素,凿形铲对土壤的疏松效果较箭形铲与翼形铲差,但其耕后地表平整度优于箭形铲与翼形铲。综合考虑作业质量、减阻效果、材料等因素,应合理确定铲尖与土壤接触面积,加强铲尖对土壤类型的适应性研究,强化带翼凿式铲铲翼的合理布置位置及其结构参数的研究。