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水载流-原子荧光光谱法同时测定土壤中痕量砷、汞 被引量:18
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作者 荣耀 贺攀红 +3 位作者 杨珍 杨有泽 孙银生 龚治湘 《中国无机分析化学》 CAS 北大核心 2021年第1期1-6,共6页
改变原子荧光光谱法以稀酸为载流的进样方式,以水为载流在新型双道原子荧光光谱仪上同时测定了土壤中的痕量砷(As)、汞(Hg)。采用王水水浴加热溶解样品,用50 g/L硫脲-抗坏血酸混合溶液预先将砷还原为As(Ⅲ),保持10%(体积分数)以上盐酸浓... 改变原子荧光光谱法以稀酸为载流的进样方式,以水为载流在新型双道原子荧光光谱仪上同时测定了土壤中的痕量砷(As)、汞(Hg)。采用王水水浴加热溶解样品,用50 g/L硫脲-抗坏血酸混合溶液预先将砷还原为As(Ⅲ),保持10%(体积分数)以上盐酸浓度,不转移直接定容静置后测定。优化了仪器工作条件,详细考察了以水为载流测定的可行性,选择了同时测定As、Hg所需的硼氢化钾浓度和盐酸浓度。节省了酸试剂用量,操作快速,单个样品测定仅需20 s左右。方法检出限As为0.005 mg/kg,Hg为0.0008 mg/kg,相对标准偏差(RSD,n=7)在1.0%~7.4%,经土壤国家标准物质和实际样品验证,适合土壤中痕量As、Hg的同时快速测定。 展开更多
关键词 水载流 原子荧光光谱法 土壤
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硝酸介质-水载流-原子荧光光谱法测定膨化食品中痕量铅 被引量:4
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作者 马琳 杨珍 +4 位作者 贺攀红 杨有泽 阿丽莉 吴培源 肖国原 《山西化工》 2022年第1期60-63,共4页
目的:建立硝酸介质下原子荧光光谱法测定膨化食品中痕量铅的分析方法。方法:通过湿法消解样品,用9%(体积分数)硝酸介质提取测定膨化食品中铅的含量。比较了干法灰化和湿法消解的优劣,考察了盐酸和硝酸介质提取的效果,讨论了硝酸酸度、... 目的:建立硝酸介质下原子荧光光谱法测定膨化食品中痕量铅的分析方法。方法:通过湿法消解样品,用9%(体积分数)硝酸介质提取测定膨化食品中铅的含量。比较了干法灰化和湿法消解的优劣,考察了盐酸和硝酸介质提取的效果,讨论了硝酸酸度、硼氢化钾浓度、氢氧化钠、铁氰化钾、铅增敏剂的用量以及共存离子Cu^(2+)、Fe^(3+)、Al^(3+)、Mn^(2+)的干扰。结果:0.1 mg/L以上的Cu^(2+)、Al^(3+)对铅的测定产生负干扰,方法检出限为3.55μg/kg,样品的加标回收率为92.7%~104.2%。结论:该方法前处理操作方便、检测速度快、灵敏度高,适合大批量膨化食品中痕量铅的测定。 展开更多
关键词 硝酸介质 水载流 原子荧光光谱法 膨化食品
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The concept, connotation and method of representation of watershed water environment carrying capacity (WWECC) 被引量:3
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作者 MENG Qing-bin ZHANG Xue SHEN Zhen-yao 《Journal of Environmental Science and Engineering》 2009年第3期37-42,共6页
Based on the relationship between water environment system and human society, water environment carrying capacity (WECC) probes into supporting ability of complex water environment system to the human society. Recen... Based on the relationship between water environment system and human society, water environment carrying capacity (WECC) probes into supporting ability of complex water environment system to the human society. Recent years, due to the shortage of water resources and serious water pollution in several watersheds in China, the research of watershed water environment carrying capacity (WWECC) becomes very important. The conception, connotation and method of representation of WWECC are discussed deeply in this paper. It shows that WWECC is a kind of index that instructs whether the water environment system in watershed can continue to support the development of social economy and ecology, it is dimensionless number. 展开更多
关键词 watershed water environment carrying capacity(WWECC) water environment carrying capacity (WECC) CONCEPTION CONNOTATION method of representation
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Investigation of the Effect of Bulbuos Bow of Containership in Head Waves Using CFD
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作者 Md. Mashiur Rahaman Hiromichi Akimoto Sharmin Shabnam 《Journal of Shipping and Ocean Engineering》 2014年第3期63-71,共9页
Reynold's averaged Navier-Stokes based CFD (computational fluid dynamics) technique WISDAM developed at The University of Tokyo is used to investigate and compare the hydrodynamic loads on container ship models SR1... Reynold's averaged Navier-Stokes based CFD (computational fluid dynamics) technique WISDAM developed at The University of Tokyo is used to investigate and compare the hydrodynamic loads on container ship models SR108 and KCS in 120 degree regular oblique wave conditions. WISDAM has the capability of handling 6DOF (six degrees of freedom) in ship motions. Finite volume method with structured and overlapping grid system is employed. The flow variables are described in staggered manner, i.e., velocity components arc defined at the face center while pressure is at the cell center. Computational results agree favorably well with existing towing tank results especially for ship motions. Computational results also show that ship with bulbous bow experience higher hydrodynamic loads on bow section. 展开更多
关键词 Bublbous bow hydrodynamic load head waves containership computational fluid dynamics
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Research on variable block size motion estimation algorithm for airborne image
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作者 王科 Huang Dongshan +1 位作者 Ma Li Zhang Yudong 《High Technology Letters》 EI CAS 2014年第3期321-327,共7页
A fast motion estimation algorithm for variable block-size using the "line scan and block merge procedure" is proposed for airborne image compression modules.Full hardware implementation via FPGA is discussed in det... A fast motion estimation algorithm for variable block-size using the "line scan and block merge procedure" is proposed for airborne image compression modules.Full hardware implementation via FPGA is discussed in detail.The proposed pipelined architecture based on the line scan algorithm is capable of calculating the required 41 motion vectors of various size blocks supported by H.264 within a 16 × 16 block in parallel.An adaptive rate distortion cost function is used for various size block decision.The motion vectors of adjacent small blocks are merged to predict the motion vectors of larger blocks for reducing computation.Experimental results show that our proposed method has lower computational complexity than full search algorithm with slight quality decrease and little bit rate increase.Due to the high real-time processing speed it can be easily realized in hardware. 展开更多
关键词 H.264 motion estimation line scan algorithm rate distortion optimization (RDO) FPGA block merge method
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