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1.
介绍了硝酸甲胺合成试验的主要试剂与仪器,阐述了硝酸甲胺合成试验的反应原理与过程,讨论了配料比和母液pH值两种不同反应终点控制方式、甲胺水溶液通入硝酸和硝酸通入甲胺水溶液两种加料方式对试验结果的影响,探究了加料速度和温度控制对对试验结果的影响,对不同方式得到的硝酸甲胺得率和纯度进行计算和比较分析,并对硝酸甲胺进行了安全性测试。  相似文献   

2.
将化工厂废硝酸直接硝化对甲苯酚制取高性价比的医药中间体邻硝基对甲酚,通过跟踪水相中游离硝酸根的紫外吸收变化,考察了油水体积比、温度、转速及硝酸与对甲酚的摩尔浓度比等因素对反应的影响,结果表明:当油水体积比为5:34、温度30℃、转速600 r/min、n硝酸:n对甲酚为1:0.8时,废水中硝酸含量下降82%,邻硝基对甲酚收率达79.5%。  相似文献   

3.
该文讨论了反应物的料比、反应时间和反应温度对复分解法制备硝酸羟胺(HAN)反应的影响,研究了蒸馏温度和真空度对硝酸羟胺稀溶液浓缩过程的影响,给出了硝酸羟胺含量的定量分析方法。  相似文献   

4.
采用静态荧光光谱分析法研究两组不同质量浓度的稀土硝酸镧、硝酸钐对杜氏盐藻生长及其叶绿素积累的影响,并对其机理进行了讨论,分别得出适宜于盐藻生长的稀土质量浓度.结果表明,硝酸镧质量浓度为2mg/L、硝酸钐的为20mg/L时的促进作用较同组其它浓度稍明显;分别观察370nm光激发叶绿素a和460nm光激发叶绿素C的荧光峰值曲线,硝酸镧和质量浓度为60mg/L的硝酸钐对盐藻培养后期叶绿素a的积累起到了抑制作用,同时2种稀土均加速了盐藻中叶绿素C的消耗.  相似文献   

5.
研究了HZSM-5催化剂上硝酸酯硝化烷基苯的区域选择性,以满足绿色硝化反应环境和经济双重要求。实验发现反应具有高对位选择性。在硅铝比为62.2的HZSM-5催化剂上,以硝酸正丙酯硝化甲苯、乙苯、正丙苯和叔丁基苯时,产物邻对比例能分别达到0.38、0.33、0.30和0.12,较甲苯硝硫混酸硝化的1.63显著降低。在所选择的几种硝酸烷基酯中,甲苯对位选择性硝化能力按硝酸正丙酯、硝酸异辛酯、硝酸异丙酯和硝酸环己酯顺序增强。  相似文献   

6.
针对传统硝酸硝化对叔丁基苯酚制备邻硝基对叔丁基苯酚存在生产效率低、安全性差等问题,本文发展了一种在微结构反应器中连续安全合成邻硝基对叔丁基苯酚的方法。首先,使用加热柱塞泵熔化固体对叔丁基苯酚实现连续进料,接着原料和高浓度硝酸在T形微混合器中迅速混合,再经管式反应器生成邻硝基对叔丁基苯酚。考察硝酸浓度、硝酸温度、硝酸与原料摩尔比、反应温度、停留时间以及总流速对对叔丁基苯酚转化率和邻硝基对叔丁基苯酚收率的影响。结果表明:硝酸浓度为7.5 mol/L、硝酸温度为22.4℃、硝酸与原料的摩尔比为1.2、反应温度90℃、停留时间10 s、总流速为2 mL/min为最优条件。在最优条件下,对叔丁基苯酚的转化率达到98.7%,邻硝基对叔丁基苯酚的收率达到79.9%。  相似文献   

7.
以硝酸为胶溶剂,采用挤条成型工艺制备了一系列MCM-22分子筛催化剂,并采用颗粒强度仪、热重天平以及氮吸附脱附-压汞方法等手段对其物理化学性质进行表征,系统考察了硝酸用量MCM-22 分子筛颗粒强度、总酸量和孔道结构等性质的影响。表征结果表明,分子筛颗粒强度随成型过程中硝酸用量的增加呈现先增大后减小的趋势,最高颗粒强度对应的硝酸用量质量分数约10%;随硝酸胶溶剂用量的增加,分子筛总酸量增加,比表面积逐渐增大,孔容先增后减。以苯和丙烯烷基化合成异丙苯为模型反应,分别采用气-液半连续和液-液连续两种操作方式对所制备分子筛的催化性能进行了实验评价。评价结果表明,当硝酸质量分数小于20%时,分子筛催化剂的活性随成型过程硝酸用量的增加而增加,当硝酸质量分数为10%时,异丙苯的选择性最大。  相似文献   

8.
HZSM-5催化剂上硝酸酯对烷基苯的选择性硝化   总被引:1,自引:0,他引:1  
研究了HZSM-5催化剂上硝酸酯硝化烷基苯的区域选择性,以满足绿色硝化反应环境和经济双重要求。实验发现反应具有高对位选择性。在硅铝比为62.2的HZSM-5催化剂上,以硝酸正丙酯硝化甲苯、乙苯、正丙苯和叔丁基苯时,产物邻对比例能分别达到0.38、0.33、0.30和0.12,较甲苯硝硫混酸硝化的1.63显著降低。在所选择的几种硝酸烷基酯中,甲苯对位选择性硝化能力按硝酸正丙酯、硝酸异辛酯、硝酸异丙酯  相似文献   

9.
硝酸的分子结构特征,决定了硝酸在水溶液中能完全电离,所以硝酸具有强酸性,根据硝酸的标准电极电势,师生可推断出硝酸又具有氧化性。  相似文献   

10.
为回收利用化工厂废硝酸,本文利用此废硝酸直接硝化对甲酚制取高性价比的医药中间体邻硝基对甲酚,以紫外吸收光谱为检测手段,跟踪游离硝酸根紫外吸光度的变化,获得最佳废酸处理工艺为:油水体积比534,温度30℃,转速600r/min,硝酸与对甲酚的物质的量之比为10.8,处理后,使废水中硝酸含量下降了82%,邻硝基对甲酚(以对甲酚计)收率达79.5%.  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.
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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