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1.
用热重法、微分热重法、和差热分析法研究药物甲磺酸多沙唑嗪在空气流中的热氧降解过程和热氧降解动力学,发现该药物的热氧降解过程由4个紧连步骤组成。用Coats-Redfern方程进行动力学处理,确定该药物热氧降解的表观反应级数分别为1.1、1.5、1.5、1.2和反应活化能为353.7,239.5,229.9和167.2kJ/mol。 相似文献
2.
张秀利 《河北科技大学学报》1995,(3)
利用诱导效应指数,分别建立了计算烷基衍生物的标准生成热、键裂能的方法,并且得到自由基的生成热的计算方法。计算了一些烷基衍生物的标准生成热、键裂能及自由基的标准生成热,平均偏差分别为2.18kJ·mol-1,2.39kJ·mol-1,1.87kJ·mol-1。 相似文献
3.
药物盐酸曲普利啶热氧降解历程及动力学研究 总被引:2,自引:0,他引:2
采用热重法、微分热重法和差热分析法研究药物盐酸曲普利啶在空气流中的热氧降解历程及动力学,从而发现该药物的热氧降解过程由5个紧连步骤组成.用Coats-Redfern方程进行动力学处理,确定盐酸曲普利啶热氧降解的表观反应级数均为1.1,反应活化能分别为66.5,113.7,116.2,153.8和180.6kJ/mol. 相似文献
4.
用射频磁控溅射法在Pt/Ti/SiO2/Si(100)结构衬底上沉积了高度C轴取向La改性的PbTiO3(PLT15)薄膜.研究了PLT15薄膜的电晕极化方法,用此方法同时对多个热释电敏感单元进行了极化.利用PLT15薄膜制备了热释电红外传感器,薄膜厚度是2μm,真空蒸发的Ni-Cr电极面积为1.2mm×1.0mm,敏感元下的Si(100)基片用热KOH和EPW进行刻蚀.用所设计的热释电系数测试系统对PLT15薄膜样品进行了测试,研究了其热释电特性.测试结果表明,PLT15薄膜样品的热释电电流ip平均为2.1×10-11A,而对应的热释电系数p为2.52×10-8C·(cm2·K)-1.这类薄膜很适合制备红外传感器 相似文献
5.
发射药热自燃的数值模拟研究 总被引:4,自引:0,他引:4
对发射药热自燃现象进行了数值模拟研究。通过与在实验室中进行的小模型实验及在野外进行的大模型实验结果的比较,确定了发射药热自燃的反应模型;在此基础上,通过数值模拟研究了直径和壁面温度对发射药热自燃的影响规律。结果发现:实验段四周壁面温度越高、实验段直径越大,发射药越容易自燃;发射药No.1比发射药No.2更容易发生热自燃。还预测了在各种温度条件下,发射药No.1与发射药No.2可能发生热自燃的直径范围。 相似文献
6.
利用极化效应指数,建立了计算正链烷基衍生物同系物的标准生成热的方法,99个可比较值的平均偏差为1.69kJ·mol-1. 相似文献
7.
建立了用基团电负性计算含氮含硫有机物键裂能的简单方法,并且得到自由基标准生成热的计算方法。计算了一些含氮含硫有机物键裂能及自由基的标准生成热,平均偏差分别为3.61kJ·mol-1,2.42kJ·mol-1。 相似文献
8.
在细菌生长的热动力学研究中,人们已建立了多种细菌生长的热谱方程[1~3].我们根据Tian[4]方程、细菌指数生长的动力学模型和自函数回归法[6],建立了一种新的细菌指数生长期热谱方程.用该热谱方程研究了枯草杆菌和白色葡萄球菌.借用化学反应中分子碰撞... 相似文献
9.
采用蔡升华质热比拟技术对首排管径增大时:s1/d=3,s2/d=1.1的顺排管束的强制对流换热进行了实验研究,管径比的范围为d1/d=1.0~1.44,Reynolds数的范围为3000~10000.通过对局部与平均换热系数的测量表明:首排管径增大时,后排管的换热与标准顺排管束相比显著增强;管径比越大,影响的排数越多;文中给出了3种管径比下的修正系数,本文的研究结果对解决现代大容量电站锅炉的对流过热器和屏式过热器的同片热偏差有着重要的意义。 相似文献
10.
本文对热作模具钢3Cr2W8V和4Cr5MoSiV1钢的耐磨性、高温拉伸、冲击性能及热疲劳抗力进行了对比研究.结果表明,4Cr5MoSiV1钢的高温强韧性优于3Cr2W8V钢,且具有更高的耐磨性及热疲劳抗力,更适宜做摩擦压力机热锻模. 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.
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.
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
16.
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
17.
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
18.
《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
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《吉林大学学报(理学版)》2014,(5):1105
<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has 相似文献