查询词典 Zn

Geochemical analyses include 'total'(concentrated HNO3 -HCl digestion) and chemical forms (three step sequential digestion, reducible, oxidizable and residual forms) of heavy metals Cu, Zn, Pb, Cr,Fe and Mn, iron oxides dithionite-citrate-bicarbonate (DCB and ammonium in the dark extraction as the estimation of total and amorphous iron oxides, respectively, total sulfur and organic matter.

化学分析包括重金属（Cu、Zn、Pb、Cr和Fe、Mn）"总量"（浓HNO3、HCl提取，非严格的总量）、形态（三步提取法，可还原态、可氧化态和残渣态）、氧化铁（连二亚硫酸钠－柠檬酸钠－重碳酸钠提取和草酸铵提取分别估计总氧化铁和无定形氧化铁）、总硫和有机质，并比较了DCB提取前后样品磁性特征的变化。

Whenpyridine was used as reductive decomposing agent, the expecting cholest-4-en-3,6-dione-22-al was obtained. However, when Zn/HOAc was used to decomposethe ozonide, C-4,5 double bond was further reduced to give cholest-3,6-dione-22-al as main product. 2 For the side-chain construction of compound (1), the solid-liquid phase-transfer Wittig reaction was used. When (3-methyl-2-oxobutyl)-triphenylarsonium bromide was used as reagent, the reaction can be carried out inmild reaction condition and the yield is higher than that when phosphorane wasused.

但使用Zn／HOAc作为分解剂时，却得到其氢化产物胆甾-3， 6-二酮-22-醛；2在甾体支链引入过程中，采用固-液相转移Wittig反应的方法，用(3-甲基)-2-氧丁基三苯基溴化胂作为试剂，反应在非常温和的条件下便可完成，而且产率比传统采用膦烷的方法更高；3在对某些甾酮化合物的选择性还原反应研究时，发现在〓还原体系中，当加入某些金属离子后，反应有更好的区域选择性和立体选择性。

And the content of heavy metal elements including Cu,Zn,Pb,Cd and As,etc in the sediment on the bottom of Baoshan River are all seriously higher than the standard value.The paddyfield along both sides of Baoshan River has been seriously poll...

宝山河底泥中Cu，Zn，Pb，Cd，As等重金属含量严重超标；宝山河两侧稻土污染严重，应是宝山河水灌溉所致；宝山河流域稻米Cd，F污染十分严重，已经严重影响到当地居民的身体健康。

The accumulated Ca and Zn in root mainly distributed in pericycle tissues, while the accumulated Cl was mainly in cortex tissues.

根系累积的Ca、Zn和K主要分配到中柱中，Cl主要分配到皮层中。

However, Zn- phenanthrene and Cd- phenanthrene were synergistic.

Zn和菲，Cd和菲之间的交互作用，无论是对脲酶还是脱氢酶均表现为协同作用。

The adsorption capacity of microcrystalline phenolphthalein was found to be 25.8 mg/g for Zn.

微晶酚酞对Zn的吸附容量为25.8 mg/g；富集因数可达200倍，回收率在97.7%～102%之间， RSD小于2.7%。

The ratios of deficiency of Fe. Ca and Zn and plumbism are relatively high, while the ratios of deficiency Mg and Cu are rather low.

开封市2~6岁儿童全血Fe、Ca、Zn缺乏和铅中毒有相当高的比率，Mg和Cu缺乏的比率较低。

The result of factor analysis can provide the changes of relative precipitation and temperature variations. In trace elements, Cu, As, Zn, Pb and Ni were apparently enrichmented in soil layers and are sensitive to climatic changes. Carbon isotope is more sensitive to climatic changes than that of oxygen isotope in loess stratigraphy. The heavy mineral are varified in the loess stratigraphy, but their content differences between loess and palaeosol is little. Though the palynologic analyses results reveal that pollens and spores are fewer in the loess stratigraphy, they differ greatly in loess layer and palaeosol layer not only in species but also in types, i. e., the pollens and spores indicating warm and moist climate, such as Lles, Podocarpus, Polopydium, Pteris grerilliana Wall, Pterocarya and Juglans appear in palaeosol layers, while those indicating cold and dry climate such as Ephedra, Artemisia, Chinopodiaceae, Picea and Abies exist mainly in loess layers. The pollen content of broad-leaved tree mainly consisting of Pterocarya is up to 60% in palaeosol 〓, while the content of Ephedra is more than 50% in 〓 loess layer, showing that the environment differed greatly when 〓 and 〓 were formed.

当然，常量元素氧化物的组合因子分析结果可提供相对降水与相对温度在剖面的变化，因而来反映气候状况更为理想；微量元素中Cu、As、Zn、Pb与Ni在成土过程中富集明显，亦较好地反映了气候变化；稳定同位素中的碳同位素比氧同位素更能敏感记录气候的变化；研究区黄土地层中重矿物种类较多，但黄土层与古土壤层中含量差异不大；孢粉分析结果揭示，尽管研究区黄土层中孢粉总量相对较为贫乏，但黄土层与古土壤层中孢粉种属相差较大：在古土壤层内出现了指示相对暖湿环境的冬青属、罗汉松属、水龙骨属、林下凤尾蕨、枫杨、胡桃等植物孢粉，而黄土层中麻黄、藜科、蒿属及冷杉、云杉含量较高。

Both Zn and Mn increased soil proteinase activity.

结果表明，Zn和Mn对土壤蛋白酶活性的促进作用最大。

Chemometric method were used to analyze UV spectrum of TCAS-heavy metal complex, pure UV spectrum of TCAS-heavy metal complex and TCAS-heavy metal complex distribution curves toward concentration of heavy metals in solution were gained. Finally, complex constants of TCAS towards Cu, Zn, Cd and Pb were got to be 9.79、8.72、6.87 and 5.00, respectively.

采用化学计量学分析TCAS络合重金属的紫外光谱，获得了TCAS－重金属络合物的纯紫外光谱，以及TCAS、TCAS－重金属络合物随重金属浓度变化的分布曲线，并最终解析得到TCAS与Cu、Zn、Cd和Pb的络合常数分别为9.79、8.72、6.87和5.00。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。