The conditions of high resolution mass spectrometry (HRMS) for determination of trace seven kinds of PCBs were investigated. Several HRMS parameters were optimized by determination of noise to signal of these PCBs und...The conditions of high resolution mass spectrometry (HRMS) for determination of trace seven kinds of PCBs were investigated. Several HRMS parameters were optimized by determination of noise to signal of these PCBs under different resolution, emission electron energy and so on. The detection limits ranged from 10-30fg at 10 000 resolution.These PCBs in two sea products were tested at this condition.展开更多
以农用地分等成果为基础进行耕地评价与立地条件分析研究,在土地评价领域推进农用地分等成果转化应用。该文以辽宁省凌源市为例,充分利用农用地分等成果,借鉴美国LESA(land evaluation and site assessment)思想,对研究区分别进行耕地...以农用地分等成果为基础进行耕地评价与立地条件分析研究,在土地评价领域推进农用地分等成果转化应用。该文以辽宁省凌源市为例,充分利用农用地分等成果,借鉴美国LESA(land evaluation and site assessment)思想,对研究区分别进行耕地质量评价和立地条件分析,并建立凌源市耕地质量评价与立地条件分析体系。该体系评价结果将凌源市耕地分为8级,其中1和2级耕地属于自然质量条件和立地条件较优的耕地,3～5级耕地属于自然质量条件尚可,受立地条件影响差异较大的耕地,7和8级耕地属于自然质量条件较差,无任何立地条件优势的耕地。以农用地分等成果为基础建立土地评价与立地条件分析体系是切实可行的,同时在该体系中要因地制宜的选取耕地立地条件因素。展开更多
文摘The conditions of high resolution mass spectrometry (HRMS) for determination of trace seven kinds of PCBs were investigated. Several HRMS parameters were optimized by determination of noise to signal of these PCBs under different resolution, emission electron energy and so on. The detection limits ranged from 10-30fg at 10 000 resolution.These PCBs in two sea products were tested at this condition.
文摘以农用地分等成果为基础进行耕地评价与立地条件分析研究,在土地评价领域推进农用地分等成果转化应用。该文以辽宁省凌源市为例,充分利用农用地分等成果,借鉴美国LESA(land evaluation and site assessment)思想,对研究区分别进行耕地质量评价和立地条件分析,并建立凌源市耕地质量评价与立地条件分析体系。该体系评价结果将凌源市耕地分为8级,其中1和2级耕地属于自然质量条件和立地条件较优的耕地,3～5级耕地属于自然质量条件尚可,受立地条件影响差异较大的耕地,7和8级耕地属于自然质量条件较差,无任何立地条件优势的耕地。以农用地分等成果为基础建立土地评价与立地条件分析体系是切实可行的,同时在该体系中要因地制宜的选取耕地立地条件因素。
