25 research outputs found
Méthode simplifiée de calcul des valeurs génétiques des femelles tenant compte de toutes les parentés
Performance, development and use of Romanov in France
The Romanov (R) breed was imported to France in 1963. In 1987, there were 15000 purebred and 80000 FI ewes. The ewes have a high precocity and good adaptability to breeding season changes. Litter size (LS) is about 2.2 at 18 months and over 3 in adults, resulting from a high ovulation rate (OR) and a reduced embryonic mortality (EM). OR is less variable, but LS as variable as in other breeds. There are 0.8—1.9 % freemartins. In ewe lambs, the heritabilities of OR, EM and LS are 0.39, 0.09 and 0.02, resp. R has a favourable direct effect on lamb viability. Heterosis is high on fertility in ewe lambs, but less on OR and LS, favourable on lamb viability. The lack of performance regression from F1 to F4 in crosses with Berrichon du Cher has allowed the creation of a composite line (INRA 401), used on farms. Ewes suckle a maximum of twins. Lambs grow fast but have a low carcass and meat quality. A good viability of crossbred lambs and a good productivity of F1 ewes have been observed both in intensive and extensive conditions. In extensive system, R ewes are relatively susceptible to gastro-intestinal parasitism but are resistant to hepatic or pulmonary parasitism. R lambs seem to be susceptible to caseous lymphadenitis. Favourable results have been obtained with regard to prolificacy of F1 or ¼ R ewes and viability of lambs in six other European countries, but an unfavourable effect of heavy summer heat on male activity and female fertility. Composite lines have been created in Spain and Hungary
Estimation de la valeur génétique des reproducteurs dans les cas d'incertitude sur les apparentements I. Formulation des indices de sélection
Estimation de la valeur génétique des reproducteurs dans les cas d'incertitude sur les apparentements II - Utilisation des durées de gestation pour le calcul des probabilités de filiation
Genetic parameters of some growth and egg production traits in laying Brown Tsaiya (Anas platyrynchos)
Compendium of Current Total Ionizing Dose Results and Displacement Damage Results for Candidate Spacecraft Electronics for NASA
Sensitivity of a variety of candidate spacecraft electronics to total ionizing dose and displacement damage is studied. Devices tested include optoelectronics, digital, analog, linear bipolar devices, and hybrid devices
The research of automobile electric control bus technology based on CAN/LIN mixed protocol
传统汽车电气控制系统中采用的点对点通信方式,对于电子化程度越来越高的汽车而言,将使其线束十分复杂,不仅增加了电气系统成本,而且会因为节点繁多使系统运行可靠性降低。总线网络能够大量减少控制线数,提高可靠性,因此,采用总线控制成为汽车电气控制系统技术发展的必然趋势。如何在汽车上建立基于总线技术的汽车电气控制系统问题自然成为汽车电子领域广受关注的研究热点。西门子公司已经利用PLC完成CAN总线控制系统,由于其具有抗干扰性强、线路简化、传输速率高、系统可任意扩展等优点,正受到国内外高度重视,但其成本高,很多国内汽车生产厂家不能接受。在这种情形下,福州源光亚明电器有限公司(沈阳中顺汽车供应商)委托厦门大...The traditional automobile electrical control system used in peer-to-peer communications, the freetly increased electronic level of automobiel makes the wiring harness more complicated by which not only increases costs, but also lower the reliability of system because of the various nodes. Bus network can decrease the number of the control lines and increase the reliability greatly. Therefore, the...学位:工学硕士院系专业:物理与机电工程学院机电工程系_测试计量技术及仪器学号:2005130175
Compendium of Single Event Effects Results for Candidate Spacecraft Electronics for NASA
Susceptibility of a variety of candidate spacecraft electronics to proton and heavy ion induced single event effects is studied. Devices tested include digital, linear bipolar, and hybrid devices