基于SLAF-seq简化基因组技术的疆岳驴遗传进化分析

畜禽资源是中国种业创新、打赢种业翻身仗的根基。疆岳驴是陕西关中驴(大型驴)和新疆驴(小型驴)经过半个多世纪杂交改良、横交固定、选育提高、培育而成的良种驴,旨在基因组水平上揭示疆岳驴的遗传进化,解析疆岳驴的遗传结构及遗传多样性。该研究利用SLAF-seq简化基因组测序鉴定疆岳驴SNP标记,构建125头样品群体进化树并进行分析。共鉴定SNP标记4887196个;通过MEGA 5软件neighbor-joining算法,构建的群体进化树显示,125头疆岳驴聚集为2个大的分支:一个分支46头聚集在一起,亲缘关系较近;另一分支79头聚集在一起,亲缘关系较近。这2个分支间亲缘关系较远。通过admixture软件、EIGENSOFT软件、SPAGe⁃Di软件进一步佐证了125头疆岳驴可分为2个群体,利用SLAF-seq简化基因组测序能全面准确地揭示疆岳驴的遗传多样性和遗传结构,为疆岳驴的关联遗传学研究和重要性状QTL定位提供依据,为争取在第3次全国畜禽遗传资源普查申报新培育品种(配套系)和疆岳驴重要性状QTL定位奠定基础。

低挥发分煤四角切圆锅炉低氮改造试验

为解决低挥发分煤着火较难、NO_x排放较高,以及传统低氮燃烧器技术在降氮的同时会进一步恶化煤粉气流着火条件的难题,耦合低氮燃烧技术与强化着火设计,对某330 MW燃用低挥发分煤四角切圆锅炉进行低氮燃烧改造。结果表明:SCR反应器入口NO_x质量浓度由550~600 mg/Nm^3(6%O_2)降至350~400 mg/Nm^3,反应器液氨耗量由150~200 kg/h降至100~150 kg/h,排烟塔NO_x排放质量浓度由70 mg/Nm^3降低至35 mg/Nm^3。

An EPR Study on Intramolecular Spin Exchange and Rotational Mobility of Nitroxides Linked by a Long-chain

The effects of pressure and solvent on the intramolecular spin exchange of biradicals having two nitroxide fragments linked by a long flexible chain were studied by means of highpressure EPR technique.It was found that the intramolecular exchange interaction between nitroxides of biradical took place through the direct contact between them.By analyzing the observed EPR spectra,we have estimated the ratio(in/out)value of the average lifetime of the radical fragments inside a cage(in)to that outside the cage(out).The in/out values decreased with decreasing temperature and increasing pressure.The results suggest that the nearly cyclic conformation in a cage is favorable in solution.Further,the rotational correlation time of individual nitroxide was estimated from the anisotropic EPR signal,and the information on the segmental motion of the nitroxide group in biradical was obtained.