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饮用水总α总β放射性测定探讨 总被引:2,自引:0,他引:2
水中放射性测量具有放射性活度低,影响测量的因素多,准确测量困难等特点。该文对饮用水总α总β放射性测量的特点以及影响放射性测量的干扰因素等进行了探讨,指出测量过程中须注意的问题以及针对这些问题应采取的措施。 相似文献
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辐射危害已经成为伴生放射性煤矿的安全问题,其中以氡及其子体、放射性粉尘、γ外照射和表面污染这四类的危害最大。采取相应的技术措施进行辐射防护,加强井下辐射监测以及矿山管理,可有效减小井下作业人员所受的辐射危害。 相似文献
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Tengfei Fan Jianguo Feng Chao Ma Chi Yu Jing Li Xuemin Wu 《Journal of Porous Materials》2014,21(1):113-119
Porous microspheres with different sizes were prepared through solvent evaporation method with ethylcellulose as a matrix material and abamectin as a core material. The abamectin-loaded microspheres were characterized through scanning electron microscopy (SEM), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The chemical structure of the microspheres was determined through FTIR. DLS analysis showed that the diameter of the microspheres range from 10 to 100 μm. SEM analysis revealed that the inner structure of the microspheres is characterized by a porous network. TGA revealed that the microspheres are thermally stable below 125 °C. The controlled release of abamectin from the microspheres into water and soil was also investigated. Abamectin was released from microspheres into water through diffusion. The release of abamectin into soil was mainly caused by erosion, a result that was verified through SEM. 相似文献
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西玛津在甘蔗及土壤中的残留消解动态 总被引:1,自引:0,他引:1
为了探明西玛津使用后在甘蔗及其土壤中的残留降解规律,采用气相色谱法研究了西玛津90%水分散粒剂在甘蔗及其土壤中的残留消解降解动态和最终残留实验。结果表明:西玛津在甘蔗和土壤中的降解动态方程分别为Ct=19.157e-0.0587t和Ct=1.689 8e-0.036t,半衰期分别为11.8 d和19.3 d;以1 647 g a.i./hm2和2 470.5 g a.i./hm2的剂量在甘蔗田进行喷雾处理,收获期甘蔗和土壤中的最终残留量分别小于0.01 mg/kg和0.02 mg/kg。 相似文献
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新型干法水泥是目前水泥行业的发展趋势,中央控制室是新型干法水泥生产线的控制指挥中心。预分解窑系统需要控制的参数较多,综合考虑各参数的变化将有利于窑系统的稳定运行。窑头和窑尾参数是准确判断窑系统运行状况的重要参数,包括窑尾的温度、压力,窑头的温度、压力,窑尾的气体分析等,在操作中应引起操作员的重视。 相似文献
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Development of microstructure in four hydrothermal reactions has been undertaken using scanning electron microscopy. These are clinker, clinker-sand, slag-lime and slag-lime-sand hydrothermal reactions. The microstructure of clinker hydration products displayed crumpled foils and tabular masses of calcium silicate hydrates; few cubic crystals of hydrogarnet appeared only during the initial stage of the reaction. In clinker-sand mixture the C-S-H phase was the only product identified. In slag-lime hydration the microstructure displayed both of the hydrogarnet crystals and the C-S-H phase. The hydration of slag-lime-sand mixture (an optimum composition) was associated with the formation of ill-crystallized tobermorite and crystalline 11A tobermorite as the main products. 相似文献
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The metabolism of malonaldehyde (MA) was investigated in vivo using male Wistar rats and in vitro using rat liver mitochondria.
Twelve hr after intubation with [1,3-14C] MA, 60–70%, 5–15% and 9–17% of administered radioactivity was recovered in expired CO2, feces and urine, respectively. In rats intubated with [1,2-14C] acetate, the corresponding values were 68–82%, 1–2% and 2–3%.14CO2 evolution was initially slower after14C-MA administration than after14C-acetate administration and more radioactivity was excreted in the feces and urine. In vitro experiments using [1,3-14C] MA showed that MA is metabolized primarily in the mitochondria via reactions involving O2 utilization and14CO2 production. The apparent Km and Vmax were 0.5 mM and 9.3 nmol/min/mg protein for O2 uptake, respectively, and 2.0 mM and 2.4 nmol/min/mg protein for14CO2 production. Addition of malonic acid to mitochondrial incubates at concentrations inhibitory to succinate dehydrogenase did
not affect MA-induced O2 uptake but enhanced14CO2 production from14C-MA.14C-Acetate appeared to be the major accumulating metabolite in rat liver mitochondrial preparations following a 120-min incubation
with14C-MA. A probable biochemical route for MA metabolism involves oxidation of MA by mitochondrial aldehyde dehydrogenase followed
by decarboxylation to produce CO2 and acetate. 相似文献
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高效液相色谱法同时测定蔬菜及水果中的吲哚丁酸和萘乙酸 总被引:1,自引:0,他引:1
采用高效液相色谱法,以DiamonsilTMC1(8250mm×4.6mm,5μm)为色谱柱,甲醇∶水∶磷酸为60∶40∶0.35(pH值3~4)作为流动相,检测波长为272nm的条件下测定萘乙酸和吲哚丁酸含量,试验结果表明:在0~50.00mg.L-1范围内线性关系良好,相关系数r吲=0.9998,r萘=0.9998,最低检出浓度为0.025mg.L-1,试样在5.00、10.00、15.00mg.L-13个添加水平下的平均回收率在81.2%~99.4%之间,相对偏差在0.41%~1.61%之间,方法简便,准确。 相似文献
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Background
Agaro-oligosaccharides derived from red seaweed polysaccharide have been reported to possess antioxidant activity. In order to assess the live protective effects of agar-oligosaccharides, we did both in vitro and in vivo studies based on own-made agaro-oligosaccharides, and the structural information of this oligosaccharide was also determined. 相似文献20.
介绍了近年来受阻胺类光稳定剂(HALS)新产品的研究开发情况,高分子量化受阻胺、多功能化受阻胺、低碱性化受阻胺和反应型受阻胺等不断出现;应用研究取得新进展,对PVC体系中有较好稳定的作用。 相似文献