兰花的栽培与管理

兰花清雅高洁,质朴纯真,风格独特,自古以来为世人所喜爱。文章对兰花形态、种类和生活习性进行了较为详尽的描述,并对兰花的栽培技术与管理方法进行了较为全面的阐述。     

Mechanical transmission of porcine reproductive and respiratory syndrome virus throughout a coordinated sequence of events during cold weather

Using a field-based model, mechanical transmission of porcine reproductive and respiratory syndrome virus (PRRSV) was assessed throughout a coordinated sequence of events that replicated common farm worker behavior during cold weather (< 0°C). The model involved fomites (boots and containers), vehicle sanitation, transport, and the movement of personnel. A field strain of PRRSV was inoculated into carriers consisting of snow and water, and carriers were adhered to the undercarriage of a vehicle. The vehicle was driven approximately 50 km to a commercial truck washing facility where the driver's boots contacted the carriers during washing, introducing the virus to the vehicle interior. The vehicle was then driven 50 km to a simulated farm site, and the driver's boots mechanically spread virus into the farm anteroom. Types of containers frequently employed in swine farms (styrofoam semen cooler, metal toolbox, plastic lunch pail, and cardboard animal health product shipping parcel) contacted drippings from footwear on the anteroom floor. The truck wash floor, vehicle cab floor mats, boot soles, anteroom floor, and the ventral surface of containers were sampled to track the virus throughout the model. Ten replicates were conducted, along with sham-inoculated controls. At multiple sampling points PRRSV nucleic acid was detected in 8 of 10 replicates. In each of the 8 PCR-positive replicates, infectious PRRSV was detected on the surfaces of containers by virus isolation or swine bioassay. All sham-inoculated controls were negative. These results indicate that mechanical transmission of PRRSV can occur during coordinated sequence of events in cold weather.     

亚麻根系还原量与主要农艺性状的相关研究

对8个有代表性的亚麻基因型根系还原量与地上部分主要农艺性状进行研究,结果表明：亚麻还原量以现蕾期至开花期最高,以后逐渐递减.其中上段根系的还原量占总还原量的73.31%-76.86%,中段根系占16.2%-18.17%,下段根系占A.95%-9.26%.亚麻根系还原量与单株果数、单株粒数、单株粒重、单株花朵数呈显著或极显著正相关,与结实率呈负相关.     

LiFePO4合成工艺的优化

利用正交实验方法优化固相反应法制备LiFePO4的合成工艺.考察合成温度、锂铁磷摩尔比、成型压强及保温时间等因素对材料电化学性能的影响.得到最佳工艺组合:锂铁磷摩尔比1.05:1:1,合成温度650℃,保温时间18 h,成型压强0 MPa.按最佳工艺合成样品的首次放电容量为131.45 mAh/g,库仑效率为96.78%.     

几种重要饲草的脂肪酸成分分析

对紫花苜蓿、苇状羊茅、鸭茅、无芒雀麦等12个饲草样品进行了脂肪酸含量的测定,并与豆油、菜籽油和棉籽油等植物油脂肪酸成分进行了比较。结果表明,饲草中的脂肪酸以亚麻酸为主,亚油酸次之,其它脂肪酸很少。植物油中的脂肪酸以油酸和亚油酸为主,亚麻酸很少。以饲草为主配合少量植物油饲喂奶牛有利于乳脂中共轭亚油酸的合成。     

阳新县竹类区划及其资源开发对策研究

由5属26个竹种组成的阳新县竹林，形成了3个分别以灰竹、毛竹、早园竹为主的代表中国毛竹水平区划3个等级的分布区。区域的界定和分区发展方向的确立，深化了湖北省和中亚热带的毛竹水平区划，为鄂东南地区森林植被类型的区域划分提供了重要的参考证据。     

种子的温度和发热

温度的变化是种子在贮藏过程中出现异常的一个重要标志.由于种子本身的代谢作用和受环境的影响,致使仓内温度逐渐发生变化,会出现发热、吸湿回潮和虫霉等异常情况.种子的温度在一年中随着气温而升降的现象大体上具有一定的规律性,掌握这种规律对防止种子发热等现象、安全保存种子有着重要的意义.     

接种猪瘟疫苗违规操作暴发猪附红细胞体病

2001年8月我区某养猪专业户为刚进场3日的两月龄119头断奶仔猪进行猪瘟疫苗预防接种,因违反技术操作规程,采取一针到底的方法,使该群仔猪暴发猪附红细胞体病.现将诊断治疗情况报告如下:     

早熟耐热大白菜新品种潍白1号

潍白１号大白菜是利用漳浦４０３和浙小４０１两个优良自交不亲和系配制而成的极早熟耐热大白菜一代杂种，具有早熟、耐热、优质、高产等优良性状，从定植到获４５～５０天，一般６６７ｍ２产量５０００ｋｇ以上，其产量、商品品质及杂种优势都明显优于夏阳。目前已在湖北、广东、广西、贵州等地推广种植     

滑动平均法在泗优9083制种中的应用

通过对泗优９０８３的母本泗稻８号Ａ与父本Ｃ９０８３的分期播种，用滑动平均的方法制成父母本的生育期用表，可供制种应用。