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1.
二茂铁的辛烷基化反应   总被引:1,自引:0,他引:1  
本文研究了二茂铁与几种不同卤代辛烷在三氯化铝存在下的付氏烷基化反应,发现烷基碳正离子的重排及几种异陶的烷基化产物的分布规律。  相似文献   

2.
研究了季铵盐A-1催化二氯卡宾与环己烯的加成反应,考察了不同相转移催化剂的催化活性、反应温度、催化剂用量、反应时间对产物7,7-二氯双环[4.1.0]庚烷收率的影响.在优化反应条件(即反应温度为50℃,反应时间为5h)下,以季铵盐A-1为相转移催化剂,产率可达94.0%.实验证明,季铵盐A-1的催化活性要优于其它短碳链的季铵盐和聚乙二醇,并且在分离过程中不乳化,使产物易于分离纯化  相似文献   

3.
研究了含氮化合物硝酸盐催化的2,10-环氧蒎烷液相重排反应的产物分布和反应机理,考察了催化剂、溶剂和反应温度对重排产物分布的影响.结果表明:2,10-环氧蒎烷的液相重排反应主要生成紫苏醇和桃金娘烯醇,产物中紫苏醇和桃金烯醇的含量达到80%以上;2,10-环氧蒎烷的液相重排反应是按碳正离子机理进行的,反应底物与质子酸H^+形成的氧翁离子转化成碳正离子中间体,再经2条途径分别生成紫苏醇和桃金娘烯醇,催化剂活性位的Bronsted酸强度和空间结构是影响重排产物分布的主要因素,并对提出的反应机理进行了讨论.  相似文献   

4.
β-甲基萘与长链烯烃烷基化研究   总被引:1,自引:1,他引:0  
详细考察了三氯化铝催化剂用量、反应温度、芳烯物质的量比、反应时间及溶剂用量对β-甲基萘与长链烯烃烷基化的影响.采用气相色谱和气相色谱-质谱联用技术表征了烷基化产物,并对结果进行了分析和讨论.找到了甲基萘与长链烯烃较佳的烷基化条件.副反应得到了有效的抑制,目标产物AMN的选择性可达100%.  相似文献   

5.
离子液体中异丁烷与丁烯的烷基化反应   总被引:1,自引:0,他引:1  
合成出一系列具有不同阴离子或阳离子结构的离子液体 ,并在高压釜中评价了这些离子液体对异丁烷与丁烯烷基化反应的催化效果以及相关反应条件的影响。实验结果表明 ,由无水三氯化铝参与合成的离子液体催化性能较好 ,其活性来源于 [Al2 Cl7]-。阳离子的类型影响产物的选择性 ,反应过程中烷基化油容易与离子液体分离。当烷、烯体积比为 4 0 ,反应温度为 6 5℃及反应时间为 2min时 ,烷基化油收率达到进料丁烯体积的 15 6 % ,其中C8组分的含量可以达到 5 7%以上 ,在催化反应过程中 ,离子液体可以重复使用。  相似文献   

6.
在热力学计算的基础上,以五氧化二钒和碳黑为原料并通入氮气一步法合成氮化钒,研究了不同配碳比(即碳黑中的碳质量与V2O5中的氧质量之比)和反应温度对氮化产物的相组成和化学成分的影响。实验结果表明,原料配碳比直接影响氮化产物氮含量,当配碳比增加时氮化产物氮含量会减少;按理论配碳比添加碳黑,可以获得成分合适的氮化产物;随着反应温度的升高,氮化产物碳含量迅速降低,氮含量逐渐增加,反应温度在1300~1500℃范围内时氮化产物的物相组成均为VN.  相似文献   

7.
利用热重分析实验得出玉米芯气化可大致分为3个阶段:水分蒸发、挥发分析出和焦炭阶段.研究表明,当升温速率为20℃/min时,物料的最大失重率只有85.75%,在所有的升温速率中最小;当升温速率为10℃/min时,物料的最大失重率可达到97.94%.以升温速率为5℃/min的热重曲线研究玉米芯气化过程中的挥发分析状况,当温度在250℃-330℃时,气化反应属于2级反应,其拟合方程Y=-2332.3x-7.9534,活化能E和指前因子A分别为19.4kJ/mol和3.4×10^4min;温度在330℃~530℃时,气化反应属于1级反应,其拟合方程Y=-1960.5x-9.7076,活化能E和指前因子A分别为16.3kJ/mol和5.0×10^1min^-1.  相似文献   

8.
以3种不同孔径γ-Al2O3为载体制备固载化AlCl3/γ-Al2O3催化剂,考察了各催化剂在苯与苄基氯烷基化合成二苯基甲烷反应中的催化活性及产物选择性,并同纯AlCl3催化剂进行了比较.采用气相色谱法分析反应产物组成,获得了不同催化剂在不同反应温度下的烷基化反应试验数据,在确定反应动力学方程及消除外扩散影响前提下,计算了反应速率常数、反应表观活化能和扩散系数.结果表明,同均相纯AlCl3催化剂相比,在固载化AlCl3催化剂上反应速率较低而且存在诱导期,且载体孔径越小,该现象越明显.动力学分析认为产生这一现象的主要原因是载体对反应内扩散的影响.  相似文献   

9.
本文研究了在SO4^2-/ZrO2作用下乙苯乙烯烷基化反应的产物组成,运用色谱-质谱联用、色谱-红外联用技术成功地鉴别出各产物异构体,并用GC考察了反应温度、原料配比、催化剂用量对反应物各异构体分布的影响。  相似文献   

10.
对Fe-Cr-Ni-O体系碳还原产物的组成与特性进行探讨。首先对不同温度及碳氧摩尔比条件下Fe-Cr-Ni-O体系碳还原产物进行热力学分析,然后对Fe-Cr-Ni-O体系及模拟不锈钢粉尘进行等温碳还原实验,并对还原产物进行系统分析。研究结果表明:升高温度有利于体系中各金属氧化物的还原及合金相的生成;当碳氧摩尔比(nC:nO)小于1.0时,体系中金属氧化物尤其是Cr2O3的还原不完全;当碳氧摩尔比大于1.0时,还原产物中容易出现金属碳化物。当碳氧摩尔比为1.0时,渣铁分离效果较好。此外,温度主要影响反应后期的失氧速率,而碳氧摩尔比主要影响样品的最终失氧率,但温度与碳氧摩尔比对反应前期的影响均不大;推断前期主要发生Ni O和Fe2O3的还原,而后期主要发生Cr2O3的还原。  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.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
<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   

20.
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