Genetic polymorphisms of milk epithelial mucin of yaks

Milk epithelial mucin (MUC1) of yaks was separated by SDS-polyacrylamide gel electrophoresis. A total of nine types of MUC1 were revealed in 427 yaks from five yak breeds including Maiwa yak, Jiulong yak, Tianzhu white yak, Qinghai yak and Tibetan yak. The molecular weights of MUC1 are from 163 kD to 208 kD, most of which are larger than those of bovine. Population genetic analysis shows that the gene frequency and genotype frequency of yak MUC1 differ among breeds, with relatively high gene heterozygosity. The five yak breeds studied fall into two groups according to their milk MUC1 gene frequency, suggesting that milk MUC1 exhibits specificities for local yak groups.     

迈向建设法治政府的重要里程碑--对我国新近颁布和实施的《行政许可法》的简要评价

我国以往行政管理体制中，设定权及设定事项不够规范明确，实施者暗箱操作、有权无责导致许可过多过滥设置。《行政许可法》的颁行有助于转换政府职能，消除部门分割、地方封锁及部门间推诿扯皮，效率低下。同时有效防止腐败、滥用权力和偏私歧视。其不足是没有明确临时性许可的实施期限，建议以不超过两年为实施期限；应认真学习理解这部法律，清理相关文件和抓紧人员培训。     

Gilpin-Ayala两种群生物竞争模型的稳定性

利用构造平均Liapunov函数法,讨论具有反应扩散项的Gilpin-Ayala两种群生物竞争模型正的平衡态的稳定性,给出了稳定性的判定条件。     

从周边合作环境中寻求我国西北地区经济崛起之契机

我国西北地区相邻的国家和地区地域广阔，大多为发展中国家和地区，其经济发展水平差距大，合作开发潜力广，且与我国具有特殊的地缘文化优势．这种情况决定了我国西北地区与周边相邻国家区域合作的特殊性．西北地区与周边国家合作的总体目标模式应分为两个层次：第一层次应根据各自经济发展的实际需要建立不同规模、内容、形式和范围的合作关系，在重点领域寻求发展途径．第二层次在总结经验的基础上进一步寻求各自经济发展的新领域．逐步扩大双方的合作领域，从而使我国西北地区与周边国家经济合作的力度更高一筹，实现共同发展的目标.     

衍射法测径中的光场偏振效应

本文给出了金属细丝的电磁场衍射公式。对金属缝和互补屏窄条或细丝的线偏光衍射作了实验和理论研究,定量给出衍射法测量细金属丝直径的偏振效应。理论计算与测量结果基本一致。 关键词：     

A novel synthetic use of 2-bromo- 1-methylpyridinium iodide for macrolactamization

Using 2-bromo-1-methylpyridimium iodide as carboxyl activating agent, 10 ansa-macrolactams were prepared conveniently from the corresponding seco-precursor w-aminoacids in the yields of 78-2%.     

HL-1装置石墨孔栏杂质收集探针的俄歇电子能谱及孔栏表面分析

在HL-1装置的输样机构上安放了硅收集探针。经过55次高功率托卡马克放电辐照后,对于因石墨孔栏被腐蚀而溅射蒸发,并沉积在硅收集探针上的杂质涂层进行了俄歇电子能谱(AES)分析,获得无主动冷却石墨孔栏被腐蚀而溅射蒸发出来的碳杂质流通量约为8×10~(13)cm~(-2)·S~(-1),金属重杂质镍和铬较GH39高镍钢孔栏时降低44％左右。     

高斯光束照射下的近似Talbot自成像效应及其两种新应用

本文讨论了高斯光束照明下的Talbot近似自成像的性质.提出了利用Talbot自成像测量高斯光束发散角的简便方法;也提出在满足一定条件下,可得到自成像的超高倍放大率.     

PrxLa1-xP5O14的发光理论和浓度效应

本文利用Judd-Ofelt理论求得PrP₅O₁₄晶体的振子强度参数Q₂,比较了计算和实验的振子强度,计算了³P₁,³P₀,¹D₂和¹G₄能级的电偶极和磁偶极辐射跃迁几率及¹D₂→¹G₄和³H₄→³F₄能级对间的多极矩耦合的无辐射迁移几率。讨论了¹D₂能级发射强度的浓度效应。并且,给出¹D₂能级发射强度的表达式和强度随着浓度和单位时间内激发光引起的³H₄到¹D₂跃迁的诱导跃迁几率的变化图。 关键词：     

The determination of an equivalent elastic modulus for bodies with cracks by boundary element method

The equivalent elastic modulus of cracked bodies with orderly distributed cracks was computed with the boundary element method. A practical self-consistent scheme has been proposed in consideration of the mutual interaction effects of the cracks. The influence of friction coefficients and orientation of cracks has been investigated. Some computational examples have been given, and the results show that the proposed method is adequate and the scheme is efficient.This project is supported by the National Natural Science Foundation of China.