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1.
噻唑偶氮类衍生物作为一系列元素的分光光度法测定的显色剂已被多次描述.最有效和最常用的是4—(2-噻唑偶氮)一间苯二酚,1—(2-噻唑偶氮)—萘酚,2—(2-噻唑偶氮一对甲苯酚等试剂.我们曾合成了一系列在变色酸的基础上,噻唑环上有不同取代基的噻唑偶氮化合物.  相似文献   

2.
本文报道了三氮烯类试剂的结构分析。以我们新合成的化合物2—氯—4—硝基苯基重氮氨基偶氮苯为研究对象,用元素分析、紫外可见光谱、红外光谱、核磁共振谱和质谱对其进行结构分析。分析结果与设计结构完全一致。  相似文献   

3.
介绍了近八年来吡啶偶氮试剂的国内合成及在极谱分析、色谱分析和络合滴定等方面的应用情况.报道了吡啶类三氮烯试剂是值得开发的新领域  相似文献   

4.
本文报导了四种新偶氮罗丹宁类显色剂的合成、纯化、结构表征以及四种新试剂在TritonX-100存在下与钯(Ⅱ)的显色反应.四种新试剂分别为5—(对甲苯基偶氮)—罗丹宁(Ⅰ)、5—(邻氯对硝基苯基偶氮)—罗丹宁(Ⅱ)、5—(2,4—二硝基苯基偶氮)—罗丹宁(Ⅲ)和5—(4—氨磺酰基苯基偶氮)—罗丹宁(IV).实验表明,上述试剂在合适的pH下均可与钯(Ⅱ)形成稳定的配合物,最大吸收波长位于530nm左右,Δλ大于70nm。表观摩尔吸光系数大于2.0×104L·mol-1cm,方法曾用于催化剂中钯的测定,结果满意.  相似文献   

5.
采用电弧熔炼和退火的方法,成功地制备了Mn3+xSn1-x(x=0.1,0.05,0)系列样品。采用热重-热扫描(TG-DSC)研究了Mn3.1Sn0.9的吸氮峰,并成功氮化出Mn3.1Sn0.9N化合物。X射线衍射,扫描电镜和能谱X射线分析证明Mn3.1Sn0.9与Mn3.05Sn0.95均为Mn3Sn单相。而Mn3.0Sn1.0样品为Mn1.77Sn与Mn3Sn两相共存。在N2气氛下Mn3.1Sn0.9的TG-DSC曲线显示,在1151K和1267K出现2个吸氮峰。在1151K对Mn3.1Sn0.9渗氮得到Mn3.1Sn0.9N单相。Mn3.1Sn0.9与Mn3.1Sn0.9N化合物的结构相关,但各自的Mn原子间距差别明显。在Mn3.1Sn0.9N的八面体间隙位引入N原子,通过相邻2层的间隙或者同一层的间隙才能进入体心位。这也说明在TG-DSC曲线上出现2个连续的、相隔不远的吸氮峰的原因。实验上也证明在2个温度渗氮得到的是相同的化合物。  相似文献   

6.
1 前言偶氮氯膦—mK 是一种不对称变色酸双偶氮化台物,学名为2—(4—氯—2—膦酸笨偶氮)—7—(3—羧基苯偶氮)—1,8—2羟基萘—3,6—2磺酸,结构式为:可简写成CPA—mK,它是测定稀土元素含量的高灵敏度显色剂之一,报道双偶氮类显色剂与稀土元素显色反应的文章较多,但偶氮氯膦—mK 与稀土元素显色反应的研究,特别是CTMAB—OP 混合表面活性剂对其显色反应的影响尚未见有报道.本文探讨了在盐酸介质中乳化剂OP 及CTMAB—OP 混合表面活性剂对稀土元素与偶氮  相似文献   

7.
以咔唑为原料,通过硝化、还原、乙酰化反应合成了3-乙酰氨基咔唑,并对反应条件进行了优化选择:在咔唑的硝化过程中,选用水作溶剂,硝酸作为硝化剂,得到产率为70%的3-硝基咔唑;在还原过程中,对不同还原剂的还原效果进行了研究,结果表明,以Sn—HCl作为还原剂,可得到产率为84%的3-氨基咔唑.并通过核磁共振谱、红外光谱及质谱对所得化合物的结构进行了表征.  相似文献   

8.
继前文,评述了近年来变色酸双伸氮类试剂的研制进展及新型多元络合体系在稀上光度分析中的应用,包括偶氮胂类、偶氮氯膦类、偶氦羧酸类、偶氮磷酸类等试剂及α型反应,β型反应以及双显色双波长光度法,组合导数分光光度法,计算数学光度法等新方法。  相似文献   

9.
采用20■×8的离子交换层析柱(氯型,200~400目;柱高×柱截面为10.5cm×16cm~2)可将 Penicillium citrinnm变异菌株产生的核酸酶 P_1对鱼精 DNA 钠盐的酶解产物——四种脱氧单核苷酸完全分离。其分离工艺条件是:0.0018N HCl,0.0028N HCl,0.035N NaCl(pH6)和0.02M NaCl—0.005N HCl(dCMP→dAMP→dTMP→dGMP);酶解液浓度2.3mg/ml左右;加样流速0.1~0.2ml/cm~2·min;洗脱流速0.5ml 左右/cm~2·min。  相似文献   

10.
本文报道了新试剂2—(3,5—二氯—2—吡啶偶氮)—5—二甲氨基苯胺的合成与提纯方法,探讨了该试剂的一些物理化学性质及其与金属离子的显色反应.  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.
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   

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 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   

15.
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   

16.
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   

17.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

18.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

19.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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