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1.
黄南平 《江西科学》2003,21(1):64-66
ε-己内酰胺与溴代十二烷,溴代辛烷,溴代已烷在氢化钠的作用下,在四氢呋喃中进行反应,合成了3种N-烷基-ε-己内酰胺,产率55%-67%,以番红、苯酚品红液等为染色剂,研究了N-烷基-ε-己内酰胺在多种植物材料染色过程中的助染作用。  相似文献   

2.
1-氨基-2-溴-4-羟基蒽醌合成新工艺研究   总被引:4,自引:0,他引:4  
设计并研究了1-氨基-2-溴蒽醌在溴化钾引发下,以硼酸为催化剂,协调4-位溴化、水解和溴离子氧化成溴素的反应速度,一浴同步直接进行羟基化的可能性和反应条件,进而提出了由-1氨基蒽酯出发,溴化-水解一浴合成1-氨基-2-溴-4-羟基蒽酯的新工艺。  相似文献   

3.
α-溴代醛是一种有用的有机合成中间体,主要用于制备α,β-不饱和醛和定向合成的光学活性异构体。本从易得的原料开始,制备一种使用方便的溴化剂-二溴麦尔多姆酸,使酯醛发生α-溴化反应不仅条件温和,操作简便,而且收率高,后处理方便。  相似文献   

4.
4-溴-3,5-二羟基苯甲酸是嘧啶类药物的中间体,以3,5-二羟基苯甲 原料合成了它并用质谱进行了表征,同时对反应条件也进行了一定探索。  相似文献   

5.
本文以对硝基乙基苯为原料,经溴化、还原和磺化反应得到染料中间体2-氨基-4-溴-5-乙基苯磺酸,并对影响反应的诸因素进行了讨论,以对硝基乙苯计产品总收率为67.1%.  相似文献   

6.
研究了镝(Ⅲ)-1,10-双(1′-苯基-3′-甲基-5′-氧代吡唑-4′-基)癸二酮-[1,10](BPMPDD)-溴化十六烷基三甲胺(CTMAB)体系的荧光性质,探讨了体系的组成比及影响体系荧光性质的多种因素,拟定了应用该体系测定Dy(Ⅲ)的新方法,在20×10-6~40×10-9mol·L-1范围内Dy(Ⅲ)浓度与荧光强度呈线性关系,检测限为33×10-10mol·L-1.将该法应用于合成样品中微量Dy(Ⅲ)的测定,结果满意  相似文献   

7.
对4-乙烯基环氧环己烷的溴化反应进行了研究。结果表明,顺式的4-乙烯基环氧环己烷与溴进行加成反应时,发生了邻基参与反应,生成五元或六元的环醚化合物;反式的4-乙烯基环氧环己烷只和溴发生加成反应,生成4-(1,2-二溴)-乙基环氧环己烷。当4-乙烯基环氧环己烷与溴等摩尔反应时,邻基参与反应的比例和加成反应的比例相等。  相似文献   

8.
腈氧化物1、3-偶极分子内环加成反应在有机功能性分子的合成中很重要,已被用来合成一系列新的立体专一性化合物,弄清此反应的机理很有意义,它可以预示产物的组成,有助于合成线路的设计。本文用过渡状态理论和量子化学AMI方法,对4-甲基-5-烯-庚腈氧化物反应机理进行研究,结果表明,虽然存在得到两种产物的平行反应,但由于两个反应的速率常数比很大,基本上只得到单一的反式产物。标题物立体专一选择性反应的大小不仅由活化焓决定,还与活化熵、反应温度和偶极矩有关,尤其是活化熵对速率常数的贡献是不可忽略的。  相似文献   

9.
7-甲氧基-5-烯-辛腈氧化物分子内环加成的立体选择性研究   总被引:5,自引:1,他引:4  
用过渡状态理论和量子化学AM1方法,对7-甲氧基-5-烯-辛腈氧化物环加成反应机理进行了研究,结果表明,存在得到2种产物的平行反应,由于2个反应的速率常数比相关不大,得到反式产物和顺式产物比例为70∶30,与实验产率比值58∶42相比,结果基本一致。标题物立体专一选择性大小由活化焓和活化熵共同决定。  相似文献   

10.
报道钯催化下,1-(2-溴苯基)-2-丙醇与一氧化碳的内酯化反应.探讨温度、催化剂、时间和溶剂对反应的影响,优选出最佳实验条件,使3-甲基-3,4-二氢-1H-苯并[C]吡喃-1-酮的收率达到95.1%.  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.
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   

18.
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   

19.
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   

20.
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   

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