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介绍了利用BTC生产过程中产生的副产品氯化氢气体合成盐酸乙脒的工艺研究。对影响反应的主要因素进行了考察,确定了最佳的工艺条件。 相似文献
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钟新仙 《邵阳学院学报(自然科学版)》2006,3(2):88-90
本文改进了用于测定羧甲基壳聚糖羧甲基取代度的灰分分析法.沉淀样品清洗直至用硝酸银溶液滴定无氯离子为止,然后灼烧成灰,再将之分散于10ml 10.1mol/L H2SO4中,用0.1mol/L NaOH标准溶液滴定,中和过量的硫酸.实验数据及计算结果表明改进的灰分分析法简单、快捷,且精确度与元素分析相当。 相似文献
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目的 用酰胺缩醛法合成1,2,4-三唑及其衍生物。方法 以甲苯为溶剂,使酰胺和DMF二甲基缩醛在110℃反应2h,得到中间产物N′-苯甲酰基-N,N-二甲基甲脒,然后,在70%乙酸溶液中,中间产物和苯肼在90℃反应3h。结果 中间产物N′-苯甲酰基-N,N-二甲基甲脒的产率达到96.5%,目标产物1,5-二苯基-1,2,4-三唑的产率为95%。结论 采用该方法合成1,2,4-三唑及其衍生物产率高,方法简单。 相似文献
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氯化钠和碱度对罗氏沼虾仔虾的毒性研究 总被引:10,自引:0,他引:10
实验研究氯化钠,碱度对罗氏沼虾仔虾的急性毒性作用,用概率单位法求出了其氯化钠,24,48,72,96h的半致死浓度分别为8.58,5.32,3.47,2.198g/L;碱度的24,48,72,96h半致死浓度分别为51.02,37.07,27.19,21.54mmol/L,对氯化钠和碱度混合作用的结果进行的方差分析表明,氯化钠和碱度对仔虾的死亡率影响显著,而两者的交互作用不显著,碱度(ALK)与罗氏沼虾仔虾氯化钠24,48h LC50(S)关系式分别S=-0.1278ALK+9.2346,S=-0.0715ALK+5.5301 . 相似文献
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流动注射化学发光测定盐酸利多卡因 总被引:7,自引:0,他引:7
酸性介质中盐酸利多卡因被质子化后与AuCl4^-形成离子缔合物.当该缔合物进入鲁米诺的逆胶束“水池”中时,离解出来的AuCl4^-与鲁米诺产生化学发光.据此建立了测定盐酸利多卡因的新方法.在优化的实验条件下。测定盐酸利多卡因的线性范围为0.5~30μg/mL,检出限(3d)为81ng/mL,对浓度为1μg/mL的盐酸利多卡因进行11次平行测定.其相对标准偏差为2.64%.将本法用于制剂中盐酸利多卡因的测定。结果令人满意. 相似文献
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采用C18色谱柱(4.6mm×250mm,5μm),以甲醇-0.02mol/L磷酸二氢钠溶液(含0.2%三乙胺,磷酸调pH值2.5,9:91)为流动相,流速1.0ml·min^-1,检测波长210nm,建立反相高效液相色谱法测定小儿清热止咳H服液中盐酸麻黄碱和盐酸伪麻黄碱含量。结果表明,盐酸麻黄碱在0.102~1.02μg范围内与峰面积呈良好线性关系,r=0.9999,平均加样回收率为97.62%,RSD为1.56%(n=6);盐酸伪麻黄碱在0.1016~1.6256μg范围内与峰面积呈良好线性关系,r=0.9999,平均加样回收率为97.55%,RSD为1.84%(,2=6)。本方法分离度好,具有良好的重复性,可以同时测定小儿清热止咳口服液中盐酸麻黄碱和盐酸伪麻黄碱的含量。 相似文献
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以粉煤灰和盐酸为原料制备FeCl3和AlCl3。考察了盐酸浓度、灰酸比、反应温度、回流反应时间等对制备FeCl3和AlCl3的影响规律。实验结果表明:盐酸浓度为1:1,灰酸比为1:25,反应温度为105℃,回流反应时间为3h时,粉煤灰中Fe^3+与Al^3+的提取效率分别可达到98.7%和99.0%。粉煤灰利用率为30.6%,为粉煤灰的应用开发、提供了实验依据。 相似文献
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采用薄层扫描法测定药材延胡索中延胡索乙素的含量.以石油醚(60~90℃)-醋酸乙酯-无水乙醇(20:17:1)为展开剂,检测波长为510nm.参比波长为600nm,Sx=3,标准曲线Y=1.098X 1.0645,r=0.9973.线性范围0.507~2.535μg,平均回收率98.0%,RSD=2.1%。 相似文献
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3,5-二氯(溴)苯乙酮的合成与表征 总被引:1,自引:0,他引:1
以对硝基苯乙酮为原料、氯化亚锡为还原剂,制备了对氨基苯乙酮,产率为68.0%.在0~5℃下对对氨基苯乙酮进行氯化和溴化,制备了3,5-二氯对氨基苯乙酮和3,5-二溴对氨基苯乙酮,产率分别为52.7%、60.8%.在亚硝酸钠盐酸体系下对中间体进行重氮化,以次磷酸为质子化试剂,合成了目标产物3,5-二氯苯乙酮和3,5-二溴苯乙酮,产率分别为60.2%、63.3%。并用阿R、MS对其结构进行了袁征. 相似文献
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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
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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
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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
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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
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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
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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
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Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
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
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Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
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
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Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
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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《上海师范大学学报(自然科学版)》2014,(5):550
<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