活塞-缸套周期性瞬态传热仿真

为解决计算柴油机单个零部件传热时边界条件难以确定的问题,用耦合传热的方法,把活塞、缸套传热时的外边界条件变成内边界处理,利用有限元软件进行建模仿真。以X6130型柴油机为例,用有限元分析软件ANSYS建立了活塞-缸套的三维模型,并对其额定工况下一个工作循环内的瞬态传热进行了仿真计算,得到了活塞-缸套上关键点的温度波动曲线。部分计算结果和实验结果对比表明：用耦合方法模拟活塞-缸套之间的传热过程是可行的,且仿真结果与实测数据吻合较好。     

板翅换热器平直翅片的传热与阻力性能试验

对11种不同结构参数的紧凑式板翅换热器平直翅片的传热和流动阻力进行了试验研究,分析比较平直翅片间距、翅片高度、翅片长度对其传热和流动阻力的影响。结果表明,翅片间距对传热和流动阻力影响较小,而翅片长度和高度对其传热和流动阻力有重要影响。同时对11种翅片的220个试验数据点进行了j因子和f因子的试验关联式拟合,拟合关联式的误差范围为±10%。     

Thyroid imaging in the dog: current status and future directions

This review describes the advantages and disadvantages of radiography, ultrasonography, and nuclear medicine in the 2 most frequent thyroid pathologies of the dog: acquired primary hypothyroidism and thyroid neoplasia. Ultrasonography and scintigraphy remain the 2 most indicated imaging modalities for these thyroid abnormalities. However, as in human medicine, computed tomography and magnetic resonance imaging also have potential indications. This is especially the case in the evaluation of the extent, local invasiveness, and local or distant metastases of thyroid neoplasia. Based on experience with different imaging modalities in people, we suggest future directions in the imaging of the canine thyroid gland.     

涉农高校技术转移中心管理模式研究

针对农业技术的特点,农业科技成果转化有其自身的规律和特征,涉农高校技术转移管 理部门要建立推转一体化的管理模式。以安徽农业大学和江南大学的模式,有效的将横向合同 管理,公益推广体系、知识产权建设及平台搭建有机结合起来。     

哺乳动物胚胎玻璃化冷冻保存的研究进展

自1985年胚胎玻璃化冷冻(v itrification)保存技术发明以来,玻璃化法先后在小鼠、兔、绵羊、牛、猪、山羊等动物胚胎上获得成功,近年来有关哺乳动物胚胎玻璃化冷冻保存的研究主要集中在冷冻和解冻方法上,相继发明了一些新的玻璃化冷冻方法:冷环玻璃化法(cryo loop)和开放式细管法(open pu lled straw,OPS),并且对解冻后细管内直接脱除防冻剂进行了广泛深入的研究,使得冷冻胚胎移植更易于在生产上推广应用。现将胚胎玻璃化冷冻的原理、冷冻保护剂、冷冻方法、解冻后保护剂脱除方法的最新研究进展作一综述。     

The fox (Vulpes vulpes) as a reservoir for canine angiostrongylosis in Denmark. Field survey and experimental infections.

Until recently, Angiostrongylus vasorum was not considered to be an endogenous Danish parasite, since demonstration of this worm had been confined to necropsy findings in 2 dogs, both of which had visited France. During the last 2 years, however, clinical cases have been diagnosed among a considerable number of Danish dogs, none of which had ever been outside Denmark. All these cases have occurred north of Copenhagen, where an endemic focus seems to exist. In this field survey A. vasorum was found for the first time in wild Danish red foxes. Furthermore, experimental infections showed that the parasite can be transferred between foxes and dogs. Consequently, the wild fox population must be considered a potential reservoir for transfer of A. vasorum to domestic dogs.     

红素氧还蛋白研究进展

自然界中大多数的红素氧还蛋白(rubredoxin)集中来自严格厌氧菌,包括细菌、古菌和少数微需氧细菌,而植物中该类蛋白相对较少,它的功能主要表现在作为辅因子或电子供体参与多个生化途径。也有研究显示,无论是植物中还是微生物中的红素氧还蛋白基因在协助生物抵御氧化胁迫方面均发挥着重要的作用。本文全面介绍自然界中的红素氧还蛋白基因的分布、结构以及在微生物、植物中所发挥的作用等,希望能为今后的进一步研究提供参考。     

泰山粗毛型长毛兔高产品系选育研究

以德系、法系安哥拉、沪２０７１ 系和ＧＳＡＢ兔为育种素材,通过合成杂交方式建立选育基础群,实施半开放式核心群世代选育,经过５ 个世代育成粗毛型兔新品系。新品系平均年产毛量１７０４ｇ,兔毛品质优良,粗毛率２０．１１％ ,料毛比４０．３３∶１,成年体重５．５ｋｇ,体长５５ｃｍ ,胸围４０ｃｍ ,平均窝产仔７．３６只,育成成活率９２％ 。适应性和抗病力较强,体质健壮,外貌整齐,遗传性稳定     

控释氮肥和尿素配比对不同品种夏玉米氮素累积、转移及其利用效率的影响

在黄淮海夏玉米生产区,不同控释氮肥和尿素的配比下,研究不同氮效率玉米品种的产量及其花前花后干物质和氮素累积分配规律,以及相应的氮素利用效率与经济效益,为该区域夏玉米氮肥高效施用提供理论与技术依据.试验采用裂区设计,周期为两年,以施氮处理为主区,设置0、180、300 kg·hm-23个施氮水平,并在180 kg·hm-...