共查询到20条相似文献，搜索用时 312 毫秒
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利用水杨醛对壳聚糖进行改性,合成壳聚糖席夫碱类衍生物(S-CTS),将其滴涂在玻碳电极表面成膜。用循环伏安法研究了该修饰电极对NO2-的电催化作用。以0.1mol/LpH4.5的B-R缓冲溶液为底液,还原峰电流与NO2-浓度在0.20～81mg/kg范围内呈良好的线性关系,相关系数为0.9899,检测限达到2.8×10-7mol/L。用于样品测定,结果较为满意。 相似文献
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微量钨、钼催化极谱的连续测定 总被引：5，自引：0，他引：5
在0.5mol/L的硫酸-0.3g/L的苯羟乙酸-3g/L的氯酸钾溶液中,钨、钼均产生单峰形极谱催化波,分别于-0.60V和-0.25V测量其峰高值,本法适用于试样中w(W)=0.5×10-6～200×10-6和w(Mo)=0.5×10-6～100×10-6的测定,标准偏差分别为0.02～0.08(W),0.02～0.04(Mo),已用于斑岩铜矿中微量钨、钼批量样品的连续测定,其结果稳定、可靠。 相似文献
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在H2SO4，NaCl介质中，钨—桑色素络合物能产生一灵敏的催化波．峰电位为-1．16V(vs．SCE)，W(Ⅵ)浓度在1．7×10^-10～3．4×10^-7mol/L范围内与峰电流呈线性关系。检测限8．5×10^-11mol/L。电化学实验结果表明该波为氢催化波。可用于痕量钨的测定． 相似文献
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钨—水杨基荧光酮络合物的极谱催化波研究 总被引：2，自引：0，他引：2
在HCl、KCl介质中,W(Ⅵ)-水杨基荧光酮络合物有一灵敏的催化波,峰电位为-1.22V(υs.SCE),W(Ⅵ)浓度在4.4×10~(-11)—4.4 ×10~(-8)mol/L范围内与峰电流呈线性关系,检测限2.2×10~(-11)mol/L。实验表明该波为氢催化波,可用于痕量或超痕量W的测定。 相似文献
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在邻苯二甲酸氢钾和醋酸混合底液(pH5.0)中,钍与茜素氨羧络合剂(ALC)形成电活性络合物，在单扫描极谱仪上于-0.60V(vs.SCE)产生一灵敏的络合吸附波，其二阶导数峰高与钍的浓度在3.0×10-8～3.0×10-6mol/L呈线性关系，检出限为1.5×10-8mol/L。用等摩尔连续变化法测得该络合物的摩尔比为nTh(Ⅳ)∶nALC=1∶1，并探讨了极谱波的性质和电极反应机理。方法用于矿石和粘土中痕量钍的测定，RSD(n=5)<4%,加标回收试验，回收率为101.5%～103.2%。 相似文献
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黄土醋酸淋溶实验及其碳酸盐组分的地球化学特征 总被引：5，自引：0，他引：5
选择性的化学淋溶实验 ,广泛用于沉积物的地球化学研究中。通过对比 1mol/L的盐酸和醋酸两种溶剂对黄土和古土壤的淋溶效果 ,发现 1mol/L的醋酸能选择性淋溶黄土和古土壤中碳酸盐组分 ,对硅酸盐、铁的氧化物等影响很小。在确定溶剂后 ,以 1mol/L醋酸溶液选择性淋溶了洛川剖面 4 3个黄土和古土壤样品 ,通过分析淋溶液的组成 ,得出黄土和古土壤中碳酸盐组分的平均成分 (wB)为 :MgO 1.71% ,MnO 670× 10 - 6 ,Sr 4 90× 10 - 6 。淋溶结果较好地反映了黄土-古土壤剖面的风化成壤程度 ,其中醋酸淋溶液中MnO含量能更好地反映当时的古气候信息。 相似文献
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与样品中基体和Rb分离了的Ca和Sr,在0.08mol/L柠檬酸-1.5mol/L NH_4OH介质中流经Dowex50×8阳离子树脂柱,并用此溶液淋洗Ca,用4mol/L HCI洗脱Sr。收集的含Sr溶液用于同位素年龄测定,消除了质谱测定过程中Ca的干扰。 相似文献
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以三种新的二苯基氧膦衍生物为载体 ,制成PVC膜化学传感器 ,研究了PVC膜对UO2 2 的电位响应特性。在pH 3 .0的0 .1mol/Ltris缓冲液中 ,以BDPPM为载体 ,考察DOP为增塑剂的电极对UO2 2 的电位响应 ,线性范围为 3 .2× 10 - 6 ～ 3.0× 10 - 2mol/L ,响应斜率为 2 9± 0 .6mV/dec,响应时间t90 % 小于 3.3min。 相似文献
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Gilles Serge Odin 《Comptes Rendus Geoscience》2002,334(6):409-414
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414. 相似文献
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正1 Introduction Geological studies established on several sections in Lanping-Simao basin have shown that the salt-bearing strata of Mengyejing formation(Yunlong Fm.in Lanping basin)are constituted by an alternation of salt layers and interbedded facies.The latter consists mainly of mudstones,and mudstone-rich conglomerate.The mineralogy and geochemistry of salt-bearing beds and 相似文献
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正On 22nd April 2014,with the approach of the 45th World Earth Day,China’s Ministry of Land and resources issued the status of China’s mineral resources in 2013.The first task of the prospecting breakthrough strategy action implemented in the last five years has been completed,and China’s security capacity for mineral resources has been significantly improved.In the 相似文献
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正There are more than 700 salt lakes with area of more than 1km2 on the Qinghai-Tibet Plateau of China.In recent years,an oilfield brine was also found in the Nanyishan Section of Qaidam Basin in the Qinghai-Tibet 相似文献
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正1 Introduction Physical and numerical models are constructed to investigate the evolution and mechanism of salt migration driven by tectonic processes.In recent years,we have designed and ran series of models to simulate salt 相似文献
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YUAN Qin LI Jianguo QIN Zhanjie WEI Haicheng SHENG Shurong SHAN Fashou 《《地质学报》英文版》2014,88(Z1):276-276
正The study of Cretaceous-Palaeogene salt-bearing strata of the Khorat Basin Laos and the Lanping-Simao Basin in Yunnan,China has an great significance not only in explaining the basin evolution and the genesis of potash 相似文献
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正Potash is one of the long-term scare deposits in China,and potash prospecting has long been listed as a key brainstorm project for our nation and geological prospecting units.There have been considerable studies in search for potash deposits in the Kuqa depression of the Tarim basin(Jackson et al.,1991;Gemmer et al.,2004;Vendeville,2005;Vendeville and Jackson,1992a,1992b), 相似文献
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正1 Introduction Qaidam Basin in Qinghai,including 43 salt lakes with multiple dominant mineral such as potassium,magnesium,lithium etc.,is the most intensive distribution of Saline 相似文献