供暖锅炉消烟除尘装置的选择

各种锅炉消烟除尘设备都有自己的使用范围,本文主要介绍了供暖锅炉在消烟除尘选用中应考虑的问题,阐明选用消烟除尘设备时要充分了解其技术范围及其经济性能。     

华南早晚造籼稻品质变化规律与定级探讨

应用国家优质稻谷标准GB／T17891-1999对华南籼稻早晚两造种植的稻谷样品进行了品质指标系统测定，结果表明：不同品种(组合)早晚造品质变化具有特异性。     

树栖型苍鹭幼鸟练飞习性的观察

1999、2000年4月～6月，在辽宁省朝阳县对树栖型苍鹭幼鸟的练飞习性进行了观察研究。苍鹭幼鸟从出壳到自由飞翔。其练飞过程分为3个时期：巢中练飞期、离巢练飞期和自由飞翔期。离巢练飞期又可分为3个阶段。章对各阶段的练飞行为进行了重点描述。     

南方山区草地资源的类型及开发利用途径

根据生态学的基本原理，对我国南方山区草地资源的特点进行了分析，从生态学类型上对该地区草地进行了划分，进而提出了南方山区草地开发利用的途径。     

松嫩平原南部羊草草地水分生态环境分析

根据1985～1989年的试验,对松嫩平原南部天然羊草(Aneurolepidium chinense)草地的水分生态环境进行了分析。研究表明:松嫩平原南部羊草草地年水分收支基本相等,但收与支的时间格局不一致,6月明显干旱,7月末地表暂时性积水;土壤含水率在生长季初期(4月)最高,雨季来临前(6月)最低;空气相对湿度在整个生长季中均较低,生长季初期尤为明显;人类对草地的过度利用已对水分生态环境造成严重的不良影响。生长季前期干旱抑制植物同化器官的充分生长和发育,使其不能有效利用雨季的大量降水;空气干旱降低植物的 CO_2同化量,二者都制约草地生产力的提高。本文还从治标和治本两个角度探讨了改善松嫩羊草草地的水分生态环境,提高生产力的途径。     

Infection with Menangle virus in flying foxes (Pteropus spp.) in Australia

Objective To examine flying foxes (Pteropus spp.) for evidence of infection with Menangle virus. Design Clustered non‐random sampling for serology, virus isolation and electron microscopy (EM). Procedure Serum samples were collected from 306 Pteropus spp. in northern and eastern Australia and tested for antibodies against Menangle virus (MenV) using a virus neutralisation test (VNT). Virus isolation was attempted from tissues and faeces collected from 215 Pteropus spp. in New South Wales. Faecal samples from 68 individual Pteropus spp. and four pools of faeces were examined by transmission EM following routine negative staining and immunogold labelling. Results Neutralising antibodies (VNT titres ≥ 8) against MenV were detected in 46% of black flying foxes (P. alecto), 41% of grey‐headed flying foxes (P. poliocephalus), 25% of spectacled flying foxes (P. conspicillatus) and 1% of little red flying foxes (P. scapulatus) in Australia. Positive sera included samples collected from P. poliocephalus in a colony adjacent to a piggery that had experienced reproductive disease caused by MenV. Virus‐like particles were observed by EM in faeces from Pteropus spp. and reactivity was detected in pooled faeces and urine by immunogold EM using sera from sows that had been exposed to MenV. Attempts to isolate the virus from the faeces and tissues from Pteropus spp. were unsuccessful. Conclusion Serological evidence of infection with MenV was detected in Pteropus spp. in Australia. Although virus‐like particles were detected in faeces, no viruses were isolated from faeces, urine or tissues of Pteropus spp.     

宁夏南部山区抗旱应灾农业技术体系的探讨

通过分析宁夏南部山区干旱气候规律及其对农业的胁迫效应，指出干旱灾害是宁南农业生产力水平低而不稳的重要原因；加强与气候条件相适应的农业技术的研究和改进，是宁南农业持续稳定发展的重要基础。结合多年来的旱地农业科技攻关研究工作，在对单项农业技术进行组装集成的基础上，建立了包括工程措施、生物措施、农艺措施、化学措施等四大措施紧密结合的宁南山区抗旱应灾农业技术体系，探讨了宁南山区抗旱应灾的主要技术策略。对于广大旱农地区提高农业系统防旱抗旱能力，实现农业高产稳产具有普遍指导意义。     

优质油菜在我国南方农业中的战略地位及其发展方略

我国是一个油料消费和进口大国,油菜是我国面积最大和发展最快的油料作物。我国油菜90％分布在南方,南方尚有大量的冬闲田可以利用,发展油菜可充分利用南方的自然资源、缓解南方人地矛盾,有利于增油、增粮、增饲、增肥,有利于南方种植业结构的调整和相关产业的发展,有利于农民增收增效。针对我国目前油菜产业存在的品质差、成本高和综合效益低等主要问题,提出了我国油菜产业发展应采取科技兴油、区域化、产业化和品牌营销战略。     

南方发展草畜业的几点思考

世界农业由子实体向营养体的转型、北方休牧还草政策的出台以及南方理想的自然条件和市场空间,为草畜业发展提供了千载难逢的机遇;南方发展草畜业不失为一条帮助农民快速致富的有效途径;只要破解观念更新、资金筹措、技术传授三大难题,草畜业定能成为南方农业的主要板块。