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Concentrations of rare earth clcments (REE) in Jurasaaic coal of YanAn Formation from Dongsheng coalfield located in the northeast of Ordos basin were determined by instrumental neutron activation analysis (INAA). Curves of distribution pattern of REE were drawn, and many geochemical parameters were calculated. The result shows that 1) The contents of REE in Jurassic coal with low ash and sulfur are lower than those of Carboniferous and Pemlian coal from the Basin of North China; 2) Inside the Dongsheng coalfield, coal from the north has higher contents of REE than that form the south because the north is near the area of source rock which is thc main supplier of REE, while the south is far away from the area of source rocks; 3) Although Jurassie coal in Dongsheng is the low-ash coal with less than 10%, the contents of REE are still proportional to ash yield of ash and SiO2 contents. 4) Ahhough the jurassic coal in Dongshcng were detposited in oxidative continental environment of river-lake, Eu depletion of REE in coal commonly exists, and positive abnomity of Ce dose not exist. This reflects the REE distribution pattern of REE in source rock of continental area; and 5) Compared with other rocks, coal shows extremely complexity of distribution pattern of RFE,which is the result of continuous alteration and redistribution of matter in coal occurred in open basin system.  相似文献   
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给出了用于靶场武器试验的相控阵跟踪测量雷达多目标工作方式与特点。提出角度、距离捕获与跟踪及丢失处理过程的工作方式,对相控阵跟踪测量雷达在设计、使用中的主要特点进行了归纳,并提出了需要解决的问题。  相似文献   
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目的:探讨乙醛脱氢酶2基因(ALDH2)Glu504Lys(G504A)多态性对中国健康受试者口服5-单硝酸异山梨醇酯缓释片(IS-5-MN)药代动力学的影响。方法:在45例人群中筛选受试者, 受试者单次口服IS-5-MN 60 mg, 采集服药后36h 内不同时间点的血样, HPLC-MS 测定IS-5-MN 的药物浓度。利用PCR-RFLP 方法对ALDH2进行基因分型, 分析不同基因型对IS-5-MN 药代动力学的影响。结果:在45例人群中筛选出22名受试者,其中野生型纯合子13例, 杂合子9例。两组基因型的IS-5-MN 血药浓度和tmax差异没有统计学意义;尽管G/G基因型与g a基因型相比, Cmax和AUC0-t 分别升高了12.4%和15.3%, 但差异均无统计学意义。结论:初步观察未发现ALDH2基因多态性与IS-5-MN 的药代动力学有关。  相似文献   
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新型微环谐振器双环模型的滤波特性分析   总被引:3,自引:3,他引:0  
设计了一种新型微环谐振器,其基本结构由圆角正方形波导与条形波导组成.根据波导光学的耦合模理论,推导出双环串联和双环并联的圆角正方形微环谐振器的光强传递函数,并通过数值模拟分别获得这两种模型的谐振器的输出特性.结果表明:与传统的圆环形谐振器相比,圆角正方形结构微环谐振器的输出光谱的通带宽、谐振峰平坦、自由光谱区范围大,更...  相似文献   
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