AFS-2202双道原子荧光计测定砷锡铋汞中应注意的几个问题     

齐素芬 《岩矿测试》2006,25(2):197-198

介绍了应用AFS-2202双道原子荧光计测定砷、锡、铋、汞的日常工作中经常出现的问题及其解决办法。  相似文献   

Investigation of hydrolysis and coagulation mechanism of poly-iron coagulant     

Ying FU Shuili YU 《中国地球化学学报》2006,25(B08):149-150

Chemical coagulation is very important in water treatment, in which coagulant is an essential part. Pre-polymerized Al^3＋ and Fe^3＋ products have been used in practice, continuously spread for many years. However, iron-based coagulant has become the focus of studies due to cumulative biologic toxicity of residual Al in treated water. Polyferric sulfate （PFS） and poly-silicic-ferric sulfate （PSF） are all pre-polymerized polymers of Fe^3＋ salts. The hydrolysis process and species distribution of Fe^3＋ ions have been investigated extensively by many chemists and water-treatment specialists. Generally, the coagulation mechanism of conventional or pre-polymerized coagulants was often studied through jar-test, absorption experiment, microstructure observation or hydrolysis species indirectly. However, few researches have been done on the hydrolysis process of PSF in detail and on the study of the coagulation mechanism using its hydrolysis species distribution until now. In this work, PSF was prepared using water glass, ferrous sulfate and sodium chlorate by a copolymerization method. The hydrolysis species distribution was theoretically derived from pH variation during hydrolysis process of PSF compared to that of polyferric sulfate （PFS）, and then characteristics [morphology, species size, Zeta potential, spectra of X-ray diffraction and infrared spectra （IR）] and coagulation performances were explored between them. Coagulation mechanism was analyzed according to hydrolysis species distribution, characteristics and coagulation performances. The results showed that PSF gives different species distribution at different pH values and characteristics from those of PFS, leading to different coagulation mechanisms between the two coagulants.  相似文献   

针铁矿-四方纤铁矿-水体系氧同位素分馏的实验研究   总被引：3，自引：0，他引：3  

徐宝龙  周根陶  郑永飞 《地球化学》2002,31(4):366-374

针铁矿是非常重要的三价铁氧化物之一,其氧同位素组成对于古环境再造具有很大的价值。以4种不同的铁化合物作为Fe3+离子的源物质,于30～120℃范围内,采用强迫水解方法,在不同同位素组成的水中分别实验合成针铁矿和四方纤铁矿。结果表明,以Fe(NO3)3·9H2O、NH4Fe(SO4)2·12H2O、Fe(SO4)3·7H2O为Fe3+源物质合成的是纯针铁矿,而以FeCl3·6H2O为Fe3+源物质合成的是四方纤铁矿。氧同位素分析显示,在30～120℃范围内实验测定的针铁矿-水体系和四方纤铁矿-水体系氧同位素分馏几乎不可区分,并且满足下列分馏关系:103lnα针铁矿-水=9.59×103/T-26.39103lnα四方纤铁矿-水=8.85×103/T-24.44实验测定的针铁矿-水体系氧同位素分馏不仅与前人实验结果一致,而且与增量方法理论计算相近。由于实验采用不同反应途径得到了一致的分馏结果,因此所测定的针铁矿-水体系氧同位素分馏代表了热力学平衡。  相似文献   

Sn、Nb、Ta氟配合物高温水解不可逆反应实验研究   总被引：3，自引：0，他引：3  

王玉荣陈文华  张海祥 《地球化学》1995,24(C00):183-190

用快速淬火高压釜测定了K2SnF6、K2NbOF5、K2TaF7在200-550℃、100MPa条件下的水解特征，并将上述溶液在500℃水解后，置于200-300℃、100MPa下进行不同时间返溶。实验测定表明，不同元素配合物水解强弱及返溶的难易程度均有不同。温度愈低、酸度愈小及时间愈短愈不可逆。不可逆的原因是水解后产物陈化，形成难溶氧化物。作者认为配合物水解血线可用来衡量水解不可逆的程度，配合物水解与返溶实验是正确了解元素地球化学行为的有效途径。  相似文献   

长心卡帕藻原生质体分离、培养研究     

张思  刘翠  金月梅  池姗  唐贤明  陈傅晓  方诩  刘涛 《海洋学报(英文版)》2014,33(10):114-123

In this study, protoplasts were successfully isolated from Kappaphycus alvarezii using snail enzymes, abalone enzymes and cellulase. The optimum enzymic ratio was fixed to be 20% of abalone enzyme, 12% of cellulase and the osmotic stabilizer was 2.0 mol/L glucose. The optimum enzymic hydrolysis conditions were found to be dark enzymolysis at 30°C continuing for 4.0 h. The resultant density and yield of protoplasts achieved 32.60×104 mL-1, 65.20×104 g-1 tissue for Kappaphycus alvarezii. Finally, under the temperature of 20°C, light intensity of 1 500–2 000 lx and photoperiod of 12 h/d, two developmental pathways were investigated:(1) callus-like cell mass and regenerated plantlet occurred on protoplast;(2) young shoots and calluslike cell mass occurred in tissue blocks after enzymolysis.  相似文献   

牡蛎水解条件的实验研究     

周慈由  黄东胜 《海洋技术学报》1998,17(1):68-70

牡蛎水解条件的实验研究周慈由黄东胜（厦门大学海洋学系,３６１００５）牡蛎是一种人们喜爱的海产品,其软体中含有丰富的糖原、蛋白质、氨基酸、维生素和微量元素。它也是一种深受欢迎的营养品,由于其含有众多生理活性物,提取物中的水溶性成分可以提高人们机体的免疫...  相似文献   

热水解-催化分光光度法测定海相碳酸盐岩中的溴          下载免费PDF全文

武丽平  袁红战  祝云军 《岩矿测试》2013,32(2):258-262

目前衡量古海洋生产力的指标都存在一定的局限性,本文提出将溴元素作为研究古海洋生产力的新指标,建立了海相碳酸盐岩的分解方法以及其中溴元素的测定方法,即热水解-分光光度法。采用热水解方法对海相碳酸盐岩样品进行分解,吸收液充分吸收其释放出的溴,分光光度法检测样品中溴元素的含量。试验确定了热水解的最佳条件和分光光度检测的最佳波长,实际样品加标回收率为97.5%～101.6%,相对标准偏差为1.2%～3.6%(n=10)。本方法的样品分解时间较短,能很好地实现溴与基体组分分离,且所需仪器均为比较常见的仪器,操作简单,成本低廉,适合于海相碳酸盐岩样品的批量分解和元素测定。  相似文献   

热水解-离子选择电极法测定海相碳酸盐岩中的氟   总被引：4，自引：4，他引：0  

高宏宇  杨祥  宋桢桢  周朝昕 《岩矿测试》2009,28(2):139-142

采用热水解法对样品进行预处理,离子选择电极法简易快速测定海相碳酸盐岩中氟元素的含量。方法检出限为25.1μg/g,精密度(RSD,n=11)为5.28%,回收率为96.5%~107.8%,结果令人满意。  相似文献   

天然林择伐10 a后林地土壤理化性质研究   总被引：2，自引：0，他引：2  

巫志龙  周新年  郑丽凤  高山  罗积长  蔡瑞添  方万春  王秀明 《山地学报》2008,26(2):180-184

对天然针阔混交林弱度和中度择伐10 a后林地土壤的理化性质进行分析,结果表明:土壤密度和结构体破坏率均下降,而最大持水量和总孔隙度均上升;土壤有机质、全氮、水解氮和全磷的含量均上升,而全钾、速效钾和速效磷的含量均略有下降.说明弱度和中度择伐10 a后林地土壤结构稳定性、水分、孔隙状况和养分含量基本得到恢复,并有所改善.  相似文献   

Structural change and mineralogical transformation mechanism of aluminum hydroxide gels from forced hydrolysis Al（Ⅲ） solutions containing AlO4Al12（OH）24（H2O）12^7＋ polyoxycation during aging     

Jing Liu  Fenghua Zhao 《中国地球化学学报》2010,29(1):107-112

The structural change and mineralogy of Al gel during aging time were investigated by using spectroscopy techniques. The results indicated that: 1) the aggregation extent of solution-gel system increases with aging time, and the structure of amorphous gel becomes more short-ordered; 2) after six months, the gel formats nordstrandite and little gibbsite; 3) a marked decrease in the number of (Al-OH)_oh bands occurring at 610 cm⁻¹ and increase in the number of (Al-OH₂)_oh bands occurring at 555 cm⁻¹ indicate that the gel undergoes rearrangement-like process during aging; 4) the gel constantly contains Al-O tetrahedron of Keggin structure, but the signal peak occurring at ≈61×10⁻⁶ of ²⁷Al MAS NMR have a slight shift to downfield with aging time. A mineralogical transformation mechanism for hydrolysis Al(III) solution was proposed.  相似文献