砂金富集规律的认识     

李尚勇 《吉林地质》1983,(2)

目前,砂金矿地质和开采工作正在各地兴起,研究并揭示砂金矿床赋存特征和砂金矿物的富集,对促进这一事业的蓬勃发展是有益的。砂金来源于原生含金地质体,所以砂金矿床赋存的空间位置,规模和品位首先受补给源的置位,范围和含金量决定。其次,对河流冲积砂金矿而言,砂矿是流水作用一定阶段的产物,所以必然受流水动力学条件的制约,而流水的动力学条件又是由山岳地貌,河谷地貌形态以及微地貌特征和沉积物性质所规定的。因此砂的富集规律研究主要  相似文献   

A thermostable serralysin inhibitor from marine bacterium Flavobacterium sp. YS-80-122     

梁朋娟  李尚勇  王昆  王芳  邢孟欣  郝建华  孙谧 《中国海洋湖沼学报》2018,36(2):483-489

Serralysin inhibitors have been proposed as potent drugs against many diseases and may help to prevent further development of antibiotic-resistant pathogenic bacteria. In this study, a novel serralysin inhibitor gene, l up I, was cloned from the marine bacterium F lavobacterium sp. YS-80-122 and expressed in Escherichia coli. The deduced serralysin inhibitor, Lup I, shows 40% amino acid identity to other reported serralysin inhibitors. Multiple sequence alignment and phylogenetic analysis of Lup I with other serralysin inhibitors indicated that Lup I was a novel type of serralysin inhibitor. The inhibitory constant for Lup I towards its target metalloprotease was 0.64 μmol/L. Lup I was thermostable at high temperature, in which 35.6%–90.7% of its inhibitory activity was recovered after treatment at 100°C for 1–60 min followed by incubation at 0°C. This novel inhibitor may represent a candidate drug for the treatment of serralysin-related infections.  相似文献