纽布病毒研究概况

纽布病毒是杯状病毒科纽布病毒属的唯一成员,是引起犊牛腹泻的新发病原。其具有广泛的地域分布,目前已在美国、英国、日本等13个国家检出,在我国奶牛和牦牛中均有检出,并发现了区别于其他基因型的新毒株,其在我国的流行情况目前还不清楚。对纽布病毒的病原学、流行病学、临床症状和检测方法进行论述,以期为纽布病毒防控提供参考。

基于恒温隔绝式荧光RT-PCR技术现场检测牛纽布病毒方法的建立及应用

纽布病毒(nebovirus,NeV)是引起犊牛腹泻的新发病原,本试验旨在建立基于恒温隔绝式RT-PCR(insulated isothermal RT-PCR,iiRT-PCR)技术现场检测NeV的方法。根据NeV的RdRp基因的保守区域,设计并合成引物和探针,优化检测体系和检测试剂预混方法,建立检测NeV的iiRT-PCR方法。结果显示,成功建立了检测NeV的iiRT-PCR方法,该方法只特异性检出NeV,对牛冠状病毒、牛诺如病毒、A群牛轮状病毒、牛病毒性腹泻病毒、牛凸隆病毒、牛大肠杆菌、牛沙门菌、牛瑞氏隐孢子虫和牛艾美尔球虫等无关病原不检出,批间变异系数为3.07%~3.12%,批内变异系数为2.45%~3.01%,检测下限为5.38 copies·μL^(-1)。应用此方法对2020—2021年采集自红原县、若尔盖县、凉山彝族自治州西昌市和阆中市的101份犊牛腹泻样本进行检测,NeV的检出率为64.36%。本研究成功建立了检测NeV的iiRT-PCR方法,具有特异性强、稳定性好和灵敏度高的特点,检测试剂预混后配合使用PetNAD核酸萃取试剂盒,可实现NeV的现场检测,从核酸提取到报告检测结果仅需1 h,操作方便,为NeV的快速诊断提供了有力的工具。

轻合金加工信息

南南铝加工有限公司铸造成功直径1 320 mm硬合金锭2 800 mm气垫炉生产线投产南南铝加工有限公司新进投产的硬合金熔铸生产线是全球最先进的熔铸造生产线之一,可与美国铝业公司达文波特轧制厂和拉斐特厂、凯撒铝业公司、肯联铝业公司纽布利萨克轧制厂、西南铝业（集团）有限责任公司、东北轻合金有限责任公司、南山轻合金公司、

民舞小词典

[纽布依]“纽布”即巫师的一种。“纽布依”,属珞巴族巫舞。巫师被珞巴族认为是人和鬼神之间的特殊“使者”,能以祭神跳鬼的祷词、咒经、模拟动作、祭献牺牲和占卜荨方式,为人祛危求安,免灾招益。巫师在为病人赎魂时,要斜挂披风,头顶上涂抹三道箭头形的酥油,表演在特定的方萝筐里进行。一般分三个部分,一、请神。巫师跪地,双目紧闭、口中念念有词,二,与神的对话。曲子短而简单,一句后加衬词“加金加”。动作步伐有:前后踏步移动,沿圈走动,

Fractal features of size distribution of Chinese intercity bus hubs

Size distribution characteristics of intercity bus hubs in China from 1997 to 2（104 were analyzed regarding highway passenger volume as a size index of intercity bus hubs. Yearly fractal dimensions of intercity bus hub sizes were exactly calculated by a novel model. Fractal dimensions of the 200 biggest intercity bus hubs from 2000 to 2004 were 1. 486 2 to 1. 511 8, and that is consistent with fractal dimensions of Chinese urban system sizes. It showed that the size distribution of intercity bus hubs had fractal structure. Fractal dimensions from 1997 to 2004 indicated that intercity bus hub size distribution grew from bi-fractal to single fractal. It is concluded that the intercity bus hub system is in evolutionary progress, and the Central Government should support large intercity bus hubs more to optimize system structure.

Coordinated scheduling model for intermodal transit hubs based on GI/M^K/1 queuing system

Coordinated scheduling of multimode plays a pivotal role in the rapid gathering and dissipating of passengers in transport hubs. Based on the survey data, the whole-day reaching time distribution at transfer points of passengers from the dominant mode to the connecting mode was achieved. A GI/M K/1 bulk service queuing system was constituted by putting the passengers' reaching time distribution as the input and the connecting mode as the service institution. Through queuing theory, the relationship between average queuing length under steady-state and headway of the connecting mode was achieved. By putting the minimum total cost of system as optimization objective, the headway as decision variable, a coordinated scheduling model of multimode in intermodal transit hubs was established. At last, a dynamic scheduling strategy was generated to cope with the unexpected changes of the dominant mode. The instance analysis indicates that this model can significantly reduce passengers' queuing time by approximately 17% with no apparently increase in departure frequency, which provides a useful solution for the coordinated scheduling of different transport modes in hubs.

美国总统对电视的利用(三)

今年春天,布什在短短的北京之行期间,利用电视树立形象可谓是独具匠心。他在抵达北京的当天就在天安门广场停留同普通人握手、谈笑。这一举动不同于尼克松访华,也区别于里根访华。实事求是地讲,布什的这些电视图像确实给人以深刻印象。这个巧妙的安排,可以看出美国总统是在利用电视与公众联络感情。电视——总统与公众联络感情的纽带美国总统无论是在竞选时期还是在任职期间都不能忽视同公众联络感情,否则就不能深得人心。总统与公众联络感情最有效的手段是利用电视树立良好形象。

迅速发展的空中摄影

谁能想到,鸽子,竟是世界上一批早期的空中“摄影师”。1908年的一天,在德国克龙贝格城的上空,突然出现了一群奇怪的鸽子。这些鸽子的腹部都绑着一个半圆形的盒子——那是用于拍照的袖珍照相机(图一)。也许,就在人们惊异不解的时候,这些“摄影师”们拍下了世界上早期的一批空中摄影作品。这些鸽子的主人是一位名叫朱利叶斯·纽布朗诺的德国人。早在1903年,他就开始研究空中摄影技术,亲自设计和监制了用于空中摄影的袖珍照相机,精心“培训”了首批空中“摄影师”。五年之后,这批“摄影师”飞上蓝天,第一次把克龙贝格一座古雅庄丽的城堡的清晰照片摆到了人们面前。

影子

维多利亚·利德尔住在纽布里奇村上边沃伦小山高处的一幢房子里。去看她的人都得走上一条陡峭的山间小道,步行50码才到得了她的小屋前。所以,她的客人不多。伍里先生每周帮她把在村里商店采购的东西带回来。沃顿博士和牧师常不时一道去看望她。