胚胎移植供受体山羊发情控制及配比问题的研究

用含１８甲基炔诺酮６０ ｍ ｇ 的阴道海绵栓预处理１１３ 只供体羊 １４～１５ ｄ后注射 Ｆ Ｓ Ｈ 进行超排,３６ ｈ 或４８ ｈ 后撤栓。１９９ 只受体羊用含炔诺酮５０ ｍ ｇ 的阴道栓处理,撤栓时注射或不注射 Ｆ Ｓ Ｈ 进行同期发情。结果表明,供、受体羊发情开始距撤栓的平均间隔时间分别为（３３．９±９９） ｈ 和（４４．３±１６．１） ｈ（ Ｐ＜ ０．０５）,供、受体羊发情持续期长短相似（ Ｐ＞ ０．０５）。撤栓时注射 Ｆ Ｓ Ｈ ２５ Ｉ Ｕ 或 ３３ Ｉ Ｕ 的受体羊,卵巢上形成功能黄体的比率分别为６４．０％ 和 ６０．７％ ,显著高于不注射 Ｆ Ｓ Ｈ的受体羊（４２．２％ , Ｐ＜ ０．０５）。结论认为,用本研究采用的超排及同期发情程序,受体撤栓时间应与供体相同或早于供体羊１２ ｈ;受体羊撤栓时应注射 Ｆ Ｓ Ｈ ２５ Ｉ Ｕ;根据供体羊回收可用胚胎数及同期发情后可用受体数量,供、受体羊的适宜比例为１∶６～１∶８。     

宝鸡地区荷斯坦奶牛发情、排卵及授精效果的比较观测

对宝鸡地区荷斯坦奶牛发情周期排卵时间、授精效果进行了调查，并对其影响因素作了分析研究。研究结果：不同产犊季节对产后第一次发情时间有显著影响，青年牛与成年牛发情后排卵时间有显著差异。产后第一、二次与三次以上发情输精受胎率有显著差异；产后母牛用药物处理和不处理，授精效果差异显著。表明，在奶牛产后子宫正常情况下，在第一、二情期授精效果最好；发情周期在19－23d受胎率提高；排卵8h内输精、受胎率最高。     

波尔山羊胚胎移植受胎率影响因素分析

（1西北农林科技大学动物科技学院,陕西杨陵712100;2洛阳市农业科学研究所,河南洛阳471022）     

无角道塞特羊胚胎移植技术研究

（西北农林科技大学生物工程研究所,陕西杨凌712100）     

山羊超数排卵和同期发情研究

用ＦＳＨ（以４种程序注射）配合ＬＨ和前列腺素对安哥拉山羊和奶山羊进行超排处理。结果表明：ＦＳＨ各给予方式的超排效果间没有显著差异（Ｐ＞０．０５）；安哥拉山羊对超排的反应弱于奶山羊（Ｐ＜０．０５）；超排后回收的可用卵母细胞数显著高于可用胚胎数（Ｐ＜０．０１）。１５－甲基ＰＧＦ２α和氯前列烯醇对奶山羊的同期发情率基本一致；但二者从注射到发情的间期具有显著差异（Ｐ＜０．０５）。注射前列腺素的时间显著影响诱导发情效率，对奶山羊而言，在情期的８～１６ｄ内使用，效果确切     

Probability of pregnancy to artificial insemination either after detected oestrus or at a fixed time in dairy cows: Influence of intrinsic and extrinsic factors in a large-scale,on-farm study

The first aim of this study was to determine the influence of the procedures [hormonal treatments for fixed time artificial insemination (FTAI) versus insemination at spontaneous oestrus (SEAI)] on several sequential inseminations (AI). A second aim was to determine the influence of some intrinsic and extrinsic factors and their interactions, including characteristics of the animals such as age, season, farm, sire, and AI technician on the response to both procedures. A retrospective analysis was performed from a data base of 120.807 AIs of healthy cows with at least 40–70 days post-partum at first service. Overall, FTAI achieved slighter greater pregnancy rates than insemination after detected oestrus. The second AI seems to be a key insemination as effects of sire and technician were greater than in the following ones. The use of FTAI or SEAI in one AI did not affect the results of the following AIs, regardless if FTAI or SEAI procedures were used in that AI. Technician had greater variation than sire or farm on final pregnancy rate. The results of each sire for pregnancy rate varied according to the type of insemination, with sires achieving greater results with one or other procedure. Pregnancy rate was positively related to the days in milk in the first two AIs. Results were greater in autumn than in spring services.     

Drive-response Synchronization for Chaotic Systems

In the drive response method of Pecora and Carroll (the PC method), the response system is copied directly from drive system and is steady subsystem of drive system. But sometimes the PC method is disabled. Therefore, another method of realizing the drive response of chaos systems is put forward in this paper. The response system is not copied directly from steady subsystem of drive system, but is constructed from arbitrarily state variable of drive system. At the same time, the driving function is added in the response system, and the method of construction is pointed out. The method can realize the chaos synchronization that can not be realized by PC method.     

Simple and High Performance Timing Synchronization in OFDM System

One ML timing offset estimation method for orthogonal frequency-division multiplexing(OFDM) systems is presented.The performance of our timing offset estimator are compared to that of H.Minn's estimator in terms of estimator variance error in both AWGN channel and multipath fading channel. Because no performance floor exists under high SNR condition,the new estimator can get more accurate estimation result with low computational complexity even under multipath fading environment.     

杂交水稻超高产制种的技术关键

阐明了杂交水稻超高产制种关键技术 :(1)安排母本比父本早 2天抽穗以充分利用父本初散花粉 ;(2 )利用药物刺激剑叶叶枕分生组织 ,创造最佳授粉态势 ;(3)利用柱头外露敏感期进行特殊技术处理 ,提高母本柱头外露率及柱头外露体积 ;(4 )在父本散粉高峰期人工辅助授粉以及创造超高产制种父母本苗架     

液压四同步马达在举升同步机构中的应用

四同步马达在液压系统中用于同步控制,其控制精度要比其它调速方式高得多。基于此,文章对液压四同步马达和举升机构的工作原理进行了分析,通过介绍液压同步马达的结构分类和特点,以公司YCNH3166垃圾中转站液压系统的4流同步马达为对象,详细阐述了其同步功能的具体实现方法以及影响液压四同步马达同步误差的主要因素和解决方法。