EDTA络合滴定法连续测定铅锌

采用盐酸和硝酸分解试样,使铅成K2SO4、PbSO4复盐沉淀与大部分干扰元素分离,过滤出复盐PbSO4,并将其溶解于HAc-NaAc缓冲溶液中,在pH =5.6 ～6时,以二甲酚橙为指示剂,用Na2EDTA滴定,所得结果为铅.滤液中加入甲基橙,用1＋ 1NH3＆#183;H2O中和至溶液成橙黄色,在pH =5.5时,以二甲酚橙为指示剂,用Na2EDTA滴定,测得结果为锌镉合量,减去镉量,即为锌量.本方法可同时连续测定铅、锌试样中的铅、锌.适用于含铅锌1％以上的试样测定.     

镉离子对硫酸锌溶液除钴的影响及机理探索

采用电子探针分析硫酸锌溶液净化渣,试图证实从硫酸锌溶液中除钴的机理。实验结果表明,Cd2 对除钴是很有益的,所以,在除钴之前把Cd2 完全除去是不完全正确的,应该把Cd2 作为除钴的一种添加剂。镉可以起到阻止碱式硫酸锌或氢氧化锌吸附在锌粉表面的作用。欲加速钴的置换和提高置换效率,必须形成锌-钴合金或锌-镉合金。锌-钴合金和锌-镉合金的共同形成比单独锌-钴合金的效果要好。锌-铜合金的形成,可能对提高除钴置换效率没有帮助。     

EDTA配位滴定法测定锌的含量

研究了用锌、稀土元素的同时配位滴定法测定锌含量的方法。在pH=5—6的缓冲溶液中，用EDTA标准溶液测定混合或单一稀土（Ⅲ）和锌（Ⅱ）的总量；然后在另一份溶液中用1，10-邻菲啰啉溶液把锌掩蔽后用EDTA标准溶液测定稀土（Ⅲ）的含量，再由稀土（Ⅲ）和锌（Ⅱ）的总量减去稀土（Ⅲ）的含量而求得锌的含量。该方法操作简便、迅速，有较大的实用性。     

EDTA滴定法快速测定锌精矿中锌量方法探讨

针对广西南丹锌精矿的特点,在参考国标方法的基础上建立锌精矿中锌含量的快速检测方法。试样用盐酸、硝酸溶解样品,氟化铵消除硅,过硫酸铵氧化锰,铁、铅、铝等离子在氯化铵-氨水溶液中形成氢氧化物共沉淀,加热后流水冷却至室温,吸取一定量的滤液,以二甲酚橙为指示剂,用抗坏血酸还原三价铁,亚硫酸钠消除铅的影响,硫脲掩蔽铜,氟化钾掩蔽铝,碘化钾掩蔽镉,在pH=5~6的六次甲基四胺缓冲溶液中,用EDTA标准溶液滴定至溶液由红色变为亮黄色为终点,测得的结果即为锌量。实验方法操作过程简单、快速、准确,测定结果的相对标准偏差RSD为0.18%,适用于锌量在10%~60%,镉量1%以下的测定。     

浅谈锌精矿中锌的快速测定方法与实验步骤

介绍了锌精矿中中锌的快速测定方法。结果表明，在pH5～6的溶液中选择碘化钾为掩蔽剂，碘化钾的用量大于5g镉才能掩蔽完全辟标准加镉回收实验当镉量小于5mg时锌回收率迭99.9％～100％，样品加标回收实验锌回收率在98％以上。     

铅锌矿中铅锌的连续测定EDTA容量法

铅测定方法是基于使铅生成硫酸铅沉淀,与锌、铜、铁、锰等元素分离、而后将硫酸铅转化为醋酸铅,在 pH 5.5—6的溶液中,以二甲酚橙作指示剂,以 EDTA 标准溶液滴定铅。锌的测定法基于硝酸、氯酸钾溶矿测定铅后的分离液中测定锌。以氢氧化铵、溴水等沉淀铁、锰、铝分离除去干扰,在 pH5—6的条件下,以 EDTA 滴定锌。其反应式:H_2Y~(-2)+Zn~(+2)→ZnY~(-2)+2H~+ 铜、镉干扰滴定以碘化钾、硫代硫酸钠消除。铝、钡、铁等部分残余干扰元素,分别以氟化铵、酒石酸消除。     

锰溶液中铵的氨气敏电极分析法

试液中锰浓度不大于2mol/L,铵浓度为10~(-3)～10~(-3)mol/L时,用EDTA掩蔽锰并调节溶液pH约为12后,用氨气敏电极测定该溶液中的铵,可得满意结果。该方法也适用于其它金属(如稀土)溶液中的铵测定。     

用巯基乙酸作解蔽剂选择性络合测定铜

本文描述了一种用巯基乙酸作解蔽剂选择性络合测定铜的方法。加入过量EDTA到铜试液中,其剩余部分用锌溶液于pH=5-6返滴定至二甲酚橙终点。然后加入巯基乙酸解蔽Cu(Ⅱ)—EDTA络合物,释放出的EDTA再同上滴定之。各种阳离子的干扰加以了研究,本法可用于测定各种试样中的铜量。     

化学法生产活性炭循环液中锌含量的测定

本文介绍了将循环使用的氯化锌溶液处理成无色,然后用EDTA容量法直接测定其锌含最的方法。操作简单,测定快速、准确。     

无汞锌锰电池的研制

为实现电池的无汞化，本文从电解质溶液入手，采用一定浓度的非水溶剂和水溶液中加入缓蚀剂的两种方法，进行自然腐蚀速度和极化曲线的测试，选择了四种配方溶液分别制成锌锰电池。并对其四种电池作了某些性能的测试，说明了所做的无汞锌锰电池的可行性．     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to