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1.
锡含量是环境水体检测的重要项目之一,因此,采用灵敏、准确的测定方法来测定环境水体中的痕量锡具有重要意义。本文结合试验,对原子荧光光谱法测定环境水体中的痕量锡进行了研究,建立了测定环境水体中痕量锡的方法。  相似文献   

2.
本文建立海水及盐卤中硼的极谱快速测定方法,在甘露醇-KCl混合底液中,用CdCO_2与酸作用以测定Cd~( )量,从而间接测定硼量,最低浓度为1P.p.m,误差±5%。  相似文献   

3.
一、前言制备硼的方法有许多人进行了研究,其中许多资料都整理在手册和专著中。根据文献记载,制备硼的方法主要有以下几种:1.金属还原法。用这种方法制硼时,最常用的原料是氧化硼,还原剂是镁。这种方法已投入了生产,粗硼的纯度为80%,经提纯后为98%。2.卤化硼还原法。用氢还原三氯化硼可得高纯度的硼。如E.Weintraub将氢与三氯化硼混合气通入电弧后制出纯度为99%的硼。L.Hackspill等在氢氛中将三氯化硼蒸气通过高频电火花后制出了纯度为99%左右的硼。  相似文献   

4.
硼铁矿提硼过程中硼的行为   总被引:3,自引:2,他引:3  
用渣-金平衡方法研究硼铁矿选择性还原过程中硼在渣-金两相的分配。矿石中的硼大约14%进入铁液中形成含硼1%左右的生铁,86%进入渣中富集,使渣中B2O3品位提高5%-6%。在高压釜内进行富硼渣碳酸钠水溶液浸出,同时通入CO2气体,硼的浸出率与富硼渣的结构,浸出温度,粒度等因素有关。在合适的工艺条件下,富硼渣中88%-90%的硼形成硼酸钠而进入溶液中,上述提硼工艺过程硼的总收率可达88%-90%。  相似文献   

5.
研究了姜黄素分光光度法测定海水中硼时基体干扰情况,探讨了消除基体干扰的措施,建立了测定海水中硼的方法,并将该方法应用于海水淡化过程中的样品分析.分析结果表明,该方法相对标准偏差为1.5%,加标回收率在92.7%~99.2%之间.  相似文献   

6.
阴离子表面活性剂的测定方法及研究进展   总被引:1,自引:0,他引:1  
大量的阴离子表面活性剂进入水体中可引起水质的恶化,已成为水质监测的一项必测指标。 文章综述了国内外近年来环境水体中阴离子表面活性剂的测定方法和研究进展。重点论述了发展较快的 分光光度法、色谱法和流动注射分析法等,并展望了在测定阴离子表面活性剂方法上的发展趋势。  相似文献   

7.
电热绝缘材料中硼的测定是制造和控制电器质量的一个重要环节,若在电热绝缘材料中加入少量的硼,则有利于某些特殊电热绝缘材料的生成,而硼的含量一旦过高,则会使材料的绝缘性能恶化,因而控制和测定其中的硼含量已成为电热绝缘材料生产中的一个很重要的研究课题.以往测硼的方法主要有姜黄素法[1]、苯羟乙酸-孔雀石绿法[2]等光度法及原子吸收法等.除原子吸收外大多数方法在测定时都往往需采用沉淀、萃取、离子交换等方法将硼与干扰元素分离或采用选择性较高的HPTA直接测定,但此方法需用浓硫酸作为介质,操作不太方便.因此,电热绝缘材料中硼的测定一直是一个有待解决的问题.由潘教麦等以甲亚胺H作测硼的显色剂,取得较好的效果[3],因此我们将此类试剂3-甲氧基-甲亚胺H应用于电热绝缘材料中硼的分析,直接分光光度法测定,获得较满意的效果.试剂的结构式为:  相似文献   

8.
本文采用偶氮胂Ⅲ分光光度法,通过对测量过程中各种条件的优化,建立了一种快速、准确测定水体中Cr(Ⅲ)的分析方法。该方法具有较好的线性,可用于环境水体样品中Cr(Ⅲ)的常规分析。  相似文献   

9.
报道一种环境水体中氨氮测定方法.采用奈斯勒试剂处理的分子筛吸收环境水体中的氨氮,形成NH2Hg2IO固相显色体,反射光谱法直接测定.探讨了该方法的基本原理、影响因素及测定条件.该方法快速、简便.线性范围1~8μg·mL-1,检测限达0.1μg·mL-1,用于地表水和污水的检测,结果满意.  相似文献   

10.
在 SDS存在下, pH6.9磷酸盐缓冲溶液中,镍与 5- (5-溴- 2-吡啶偶氮 )- 2, 4-二甲基苯 (5- Br- PADAT)反应生成黄色显色液。本文在此显色反应基础上,根据β修正光度理论研究了测定镍的新方法。该方法能准确扣除反应体系中剩余 5- Br- PADAT的吸光干扰。使β修正吸光度与镍浓度 (x)呈现良好线性关系,且分析灵敏度高,实验测得样品分析相对标准偏差 RSD 1.3%,加标回收率 96.0%- 108%。镍最低检测浓度为 0.006μ g/ml。该方法适于环境水体中痕量镍的测定。  相似文献   

11.
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.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
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.  相似文献   

15.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
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。  相似文献   

20.
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.  相似文献   

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