首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
研究了磷钼杂多酸-吖啶红-阿拉伯树胶高灵敏显色反应,提出了测定痕量磷的新分光光度法.离子缔合物的最大吸收波长位于526nm处,表观摩尔吸光系数ε为2.37×105L·mol-1·cm-1.磷浓度在0~160μg/L范围内符合比耳定律,本法具有较高的灵敏度和一定的选择性.直接用于铁、试剂和水样的分析,结果满意.  相似文献   

2.
用作者合成的新试剂 5 - (8-喹啉偶氮 ) - 2 ,3-二羟基吡啶作显色剂 ,以分光光度法测定微量钴 ,在 pH9 3的硼砂缓冲溶液中 ,配合物的最大吸收波长位于 6 2 4nm ,钴量在 0~ 2 0 μg/ 2 5ml范围内符合比尔定律 ,摩尔吸光系数为 9 0×1 0 4C·mol-1·cm-1.方法简便 ,快速 ,应用于维生素B12 和镍盐中钴的测定 ,获得满意结果  相似文献   

3.
报道了 1 - (4-硝基苯基 ) - 3 - (5 -氯吡啶 )三氮烯 (NPCPDT)的合成及其与铜的显色反应 .在OP存在下 ,在pH为 1 1 .0的硼砂 -氢氧化钠缓冲溶液中 ,该试剂能与铜发生显色反应 ,铜与NPCPDT形成摩尔比为 1∶3型的黄色配合物 ,在 4 5 0nm处有一最大正吸收 ,在 5 3 5nm处有一最大负吸收 .以 4 5 0nm为参比波长 ,5 3 5nm为测量波长进行双波长测定 ,表观摩尔吸光系数为 2 .4 2× 1 0 5L·mol-1 ·cm-1 ,铜的浓度在0~ 0 .6 μg/mL范围内符合比尔定律 .用拟定方法测定人发中的微量铜 ,结果满意  相似文献   

4.
分光光度法测定Fe(Ⅲ)-二甲酚橙显色反应的研究   总被引:2,自引:0,他引:2  
在 5× 10 -2 mol·L-1HCl溶液中 ,二甲酚橙与Fe(Ⅲ )生成紫红色络合物 ,其最大吸收波长位于5 6 0nm处 ,表观摩尔吸光系数ε =2 .0× 10 4L·mol-1·cm-1.Fe(Ⅲ )含量在 0~ 2 .4mg·L-1范围内符合Beer定律 .用于水样中微量铁 (Ⅲ )的测定 ,结果较满意  相似文献   

5.
流动注射示差动力学化学发光法同时测定硅和磷   总被引:1,自引:0,他引:1  
根据硅钼杂多酸和磷钼杂多酸能直接氧化Luminol产生化学发光 ,但两种杂多酸在相同条件时的形成速率有明显差异的特性 ,采用流动注射示差动力学分析技术 ,在硅、磷共存时 ,不经分离 ,实现对合成水样中硅和磷的同时测定 .该法测定硅、磷的检出限分别为 3 2× 1 0 -8g/mL和 6 0× 1 0 -8g/mL ;线性范围为 1 0× 1 0 -7~ 1 0× 1 0 -5g/mL和 2 0× 1 0 -7~ 8 0× 1 0 -6g/mL .相对标准偏差为 2 .8%和 3.6% .  相似文献   

6.
本文研究了在聚乙烯醇存在下,钼(Ⅵ)—SCN—甲基紫高灵敏离子缔合体系,在0·10—0·14M硫酸介质中,该体系λ_(max)=530nm,表观摩尔吸光系数_(530)=9·20×10~5l·mol~(-1)·cm~(-1),0~μgM_0/25ml符合比尔定律,选择性较好,并用于钢铁中钼的测定。对显色反应机理作了初步探讨。  相似文献   

7.
本文报告砷和磷及硅在沸水浴加热的条件下与分别于1. 32和1. 92N 硫酸及2. 4盐酸介质中,借砷钼、磷钼和硅钼的杂多酸被赤霉素还原成相对应的钼杂多兰的水相显色反应作分光光度测定微量砷、磷和硅。兰色化合物可稳定一日以上;砷、磷和硅的摩尔吸光系数分别为2. 64×10~4、 2. 4×10~4和3. 51×10~4升·摩尔~(-1) ·厘米~(-1) ;桑德尔灵敏度分别为0. 0028、 0. 0013和0. 0008微克/厘米~2。方法灵敏、准确、简便,新还原剂又很稳定,优点甚多。  相似文献   

8.
研究了在阴离子表面活性剂存在的条件下,银与2-[3,5-二溴-2-吡啶偶氮]-5-二乙氨基苯酚的反应条件。阴离子表面活性剂十二烷基硫酸钠能使Ag-2-[3,5-二溴2-吡啶偶氮]-5-二乙氨基苯酚配合物增敏,其最大吸收峰位于565nm处,摩尔吸光系数为6.4×10~4L·mol~(-1)·cm~(-1),在0~0.48μg/ml时符合比尔定律。试剂与Ag~+形成2:1的配合物。此方法用于纯铅及铅锑合金中银的测定,可获得满意的结果。  相似文献   

9.
研究了Sm(Ⅲ ) -TB·CPA -CPB -C2 H5OH体系的光度特性和最佳反应条件 ,该体系与Sm(Ⅲ ) -TB·CPA体系相比 ,灵敏度虽未见明显提高 ,但选择性显著提高 .Sm(Ⅲ )浓度在 0~ 1 2 .0 μg 2 5ml范围遵循比尔定律 ,当λmax=665nm ,表观摩尔吸光系数ε=9.8× 1 0 4L·mol-1 ·cm-1 ,方法用于矿样测定 ,结果满意  相似文献   

10.
研究了氨 -氯化铵缓冲溶液中 ,铝、氟和 1.5-二 ( 2 -羟基 - 5-磺基苯基 ) - 3-氰基甲月替(DSPCF)的显色反应 .提出一个简便、快速的测定微量铝的分光光度法 .络合物的表观摩尔吸光系数为 3.51× 10 4 L·mol- 1·cm- 1.最大吸收波长为 610nm .室温下 ,显色反应在 10min内完成 .有色络合物稳定时间至少 6h .含铝 0~ 0 .4 8μg/mL范围符合比耳定律 .该法用于铅精矿中微量铝的测定 ,获得了满意的结果 .图 1,表 1,参 5.  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.
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   

15.
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   

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.
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   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号