中小型猪场市场调查及建场类型

加入世界贸易组织后,国内畜牧业面临机遇和挑战,从分散、小规模、传统的生产方式逐步向规模化、集约化和现代化方向发展,规模化生猪养殖将是发展的必然趋势。但许多养殖户由于资金、技术及场地等限制不可能建立大型养猪场,多为中小型。通过生猪市场调查、分析和对养殖场类型及特点的归纳,正确指导从业人员科学兴办中小型猪场,提高养殖效益走上致富道路,为养殖户科学办好中小型猪场提供技术支撑和参考。     

中国种业企业竞争力现状与特点

种业企业竞争力决定企业的生存和发展。立足我国种业企业实际,通过数据比较与详细分析,着重阐述现阶段我国种业企业处于深度调整期的产业发展特点、市场营收利润及国内上市种业企业核心竞争力等方面的现状特点及存在的不足,为科学制定提高我国种业企业竞争力的合理化建议提供依据和参考。     

Currents in la jolla and scripps submarine canyons

Velocities up to 34 centimeters per second have been recorded near the floors of submarine canyons off La Jolla, California. Currents move alternately down- and upcanyon with variable periods. All 3- to 6-day measurements show net current transport downcanyon. Many of the downcanyon currents of higher velocity correlate with ebbing tides, as measured at the nearby pier. Other factors producing the currents probably include internal waves. Velocities are sufficient to transport large quantities of fine sand.     

咖啡短体线虫分子鉴定

本实验采用单条线虫法提取DNA,rDNA-ITS-PCR技术扩增目的片段(ITS1、5.8S、ITS2和部分的18S和28S),将此片段纯化回收,克隆测序分析,与GenBank比对,结果为:该种群的基因序列与AY561436(基因库编号)的相似度为92.3%,与AB053485的相似度为91.3%.分子鉴定结果与形态鉴定该线虫为咖啡短体线虫.     

Mycoplasmas isolated from the respiratory tract of cattle and goats in Tanzania

A microbiological study of the mycoplasma flora in the respiratory tracts of cattle and goats in selected regions of Tanzania is described. In the examination of cattle, mycoplasmas were isolated from 60 (17.8%) of the 338 examined lung samples, 8 (47.1%) of the 17 lymph nodes, 4 (13.3%) of the 30 pleural fluid samples and 4 (3.9%) of the 103 nasal swabs examined. All the isolates were identified as Mycoplasma mycoides subsp. mycoides, Small Colony type except for one isolate from pleural fluid which was identified as Mycoplasma arginini. M. mycoides subsp. mycoides, Small Colony type was isolated from samples originating from Dodoma, Iringa, Mbeya, Morogoro and Shinyanga regions where outbreaks of contagious bovine pleuropneumonia had been reported. In the examination of goats, mycoplasmas were isolated from 54 (34.0%) of the 159 examined lung samples, 41 (18.1%) of the 226 nasal swabs and 4 (40.0%) of the 10 pleural fluid samples. The species demonstrated were Mycoplasma capricolum subsp. capripneumoniae, M. mycoides subsp. mycoides, Small Colony type Mycoplasma ovipneumoniae and M. Capricolum subsp. arginini. The isolation of M. capripneumoniae in the Coast and Morogoro regions confirmed the presence of contagious caprine pleuropneumonia in the regions.     

The magnetic field of saturn: pioneer 11 observations

The intrinsic magnetic field of Saturn measured by the high-field fluxgate magnetometer is much weaker than expected. An analysis of preliminary data combined with the preliminary trajectory yield a model for the main planetary field which is a simple centered dipole of moment 0.20 +/- 0.01 gauss-Rs(3) = 4.3 +/- 0.2 x 10(28) gauss-cm(3) (1 Rs = 1 Saturn radius = 60,000 km). The polarity is opposite that of Earth, and, surprisingly, the tilt is small, within 2 degrees +/- 1 degrees of the rotation axis. The equatorial field intensity at the cloud tops is 0.2 gauss, and the polar intensity is 0.56 gauss. The unique moon Titan is expected to be located within the magnetosheath of Saturn or the interplanetary medium about 50 percent of the time because the average subsolar point distance to the magnetosphere is estimated to be 20 Rs, the orbital distance to Titan.     

Magnetic Field Observations near Mercury: Preliminary Results from Mariner 10

Results are presented from a preliminary analysis of data obtained near Mercury on 29 March 1974 by the NASA-GSFC magnetic field experiment on Mariner 10. Rather unexpectedly, a very well-developed, detached bow shock wave, which develops as the super-Alfvénic solar wind interacts with the planet, has been observed. In addition, a magnetosphere-like region, with maximum field strength of 98 gammas at closest approach (704 kilometers altitude), has been observed, contained within boundaries similar to the terrestrial magnetopause. The obstacle deflecting the solar wind flow is global in size, but the origin of the enhanced magnetic field has not yet been uniquely established. The field may be intrinsic to the planet and distorted by interaction with the solar wind. It may also be associated with a complex induction process whereby the planetary interior-atmosphere-ionosphere interacts with the solar wind flow to generate the observed field by a dynamo action. The complete body of data favors the preliminary conclusion that Mercury has an intrinsic magnetic field. If this is correct, it represents a major scientific discovery in planetary magnetism and will have considerable impact on studies of the origin of the solar system.     

论改进中小型养禽场经营管理与企业诊断（下）

企业和人一样，也会生病。企业诊断就是给企业看病。     

禽流感疫苗对水禽免疫效果观察

广东省是我国供港澳水禽及产品出口的主要养殖和加工基地,如何解决水禽免疫及水禽免疫带毒问题,探索科学的检疫对策以降低检疫风险是我们的工作目标.本课题的研究是基于检疫业务的需要,通过结合实际工作开展对水禽的检疫风险分析.