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1.
CH3OOH对大气OH自由基浓度水平的影响   总被引:2,自引:0,他引:2  
甲基过氧化氢(CH3OOH,MHP)是大气中各种碳氢化合物光化学反应过程生成的一种重要产物,是大气中HOx和ROx等氧化性自由基的汇和储库分子.为了研究MHP对大气OH自由基浓度水平的影响,文中利用长光路Fourier变换红外光谱(LP-FTIR)技术,在(293±2)K温度和1.01×105Pa空气压力条件下,采用光解O3和水汽的方法产生OH自由基,对MHP和OH自由基的气相反应进行了实验室模拟,结合相对速率法测定了MHP和OH自由基反应的速率常数为kMHP-OH=(3.99±0.15)×10-12 cm3·molecule-1·s-1,估算出其大气寿命为3.6 d;同时研究了MHP的紫外光解反应,对反应过程进行了详细的分析,得到了OH自由基的产率为0.91±0.04.MHP的大气寿命和光解产生OH自由基的产率表明,MHP对于OH自由基在对流层大气中的再分配具有重要的作用.  相似文献   

2.
采用4种不同粒径的Al(MHP)作为环氧树脂(EP)的阻燃剂,着重讨论了Al(MHP)的粒径对EP复合材料的阻燃性能、热性能以及EP胶粘剂的粘接强度的影响。结果表明,减小Al(MHP)的粒径能显著提高EP复合材料的热性能、分解过程中的残炭率以及EP胶粘剂的粘结强度。当Al(MHP)的粒径从36.50μm减小到4.11μm,Al(MHP)含量为17 wt%的EP复合材料的氧指数(LOI)从34%增加到39%,聚合物空气中热分解到700℃时残炭率由23%增加到31%,剪切强度由4.77 MPa增加到8.44 MPa。  相似文献   

3.
以甲基环己基次膦酸(MHP)和Na OH反应,然后与金属化合物成盐得到甲基环己基次膦酸铝/铁复盐(Al Fe(MHP))。采用FTIR、XRF及XRD等技术表征其结构。作为阻燃剂应用于环氧树脂(EP)后,对复合材料的燃烧性能及热稳定性进行初步探讨。结果表明,当阻燃剂添加量(质量分数)为10%时,EP的极限氧指数(LOI)从19.8%提高到28.4%,垂直燃烧测试达到UL94 V-0级别。热重分析显示Al Fe(MHP)的热稳定性良好,燃烧性能测试证实Al Fe(MHP)对复合材料的热释放速率(HRR)抑制作用明显。  相似文献   

4.
Methyl hydroperoxide (CH3OOH, MHP) is known to be a significant sink and reservoir of HOx and ROx radicals in the atmosphere. In order to investigate the impact of MHP on the concentration of atmospheric OH radicals, two key gas-phase reactions of MHP, i.e. the reactions with OH radicals and with UV photolysis, have been simulated at temperature of 293±2 K and total pressure of 1.01×105 Pa, using the long path Fourier transform infrared (LP-FTIR) spectrometry. OH radicals are generated by the photolysis of O3 in the presence of water vapor. Combined with the relative rate method, the reaction rate constant of MHP with OH radicals is determined to be (3.99±0.15)×10-12 cm3?molecule-1?s-1, and thus the atmospheric lifetime of MHP is estimated at 2.9 days. Furthermore, from detailed analysis of the UV photolysis of MHP, the yield of OH radicals is obtained to be 0.91±0.04. Based on the MHP atmospheric lifetime and the yield of OH radicals, it is concluded that MHP plays an essential role in the redistribution of OH radicals in the troposphere.  相似文献   

5.
甲基过氧化氢(CH3OOH, MHP)是大气中各种碳氢化合物光化学反应过程生成的一种重要产物, 是大气中HOx和ROx等氧化性自由基的汇和储库分子. 为了研究MHP对大气OH自由基浓度水平的影响, 文中利用长光路Fourier变换红外光谱(LP-FTIR)技术, 在(293±2)K温度和1.01×105Pa空气压力条件下, 采用光解O3和水汽的方法产生OH自由基, 对MHP和OH自由基的气相反应进行了实验室模拟, 结合相对速率法测定了MHP和OH自由基反应的速率常数为kMHP-OH = (3.99±0.15)×10-12cm3·molecule-1·s-1, 估算出其大气寿命为3.6d; 同时研究了MHP的紫外光解反应, 对反应过程进行了详细的分析, 得到了OH自由基的产率为0.91±0.04. MHP的大气寿命和光解产生OH自由基的产率表明, MHP对于OH自由基在对流层大气中的再分配具有重要的作用.  相似文献   

6.
Methyl hydroperoxide (CH3OOH, MHP) is known to be a significant sink and reservoir of HOx and ROx radicals in the atmosphere. In order to investigate the impact of MHP on the concentration of atmospheric OH radicals, two key gas-phase reactions of MHP, i.e. the reactions with OH radicals and with UV photolysis, have been simulated at temperature of 293±2 K and total pressure of 1.01×105 Pa, using the long path Fourier transform infrared (LP-FTIR) spectrometry. OH radicals are generated by the photolysis of O3 in the presence of water vapor. Combined with the relative rate method, the reaction rate constant of MHP with OH radicals is determined to be (3.99±0.15)×10-12 cm3?molecule-1?s-1, and thus the atmospheric lifetime of MHP is estimated at 2.9 days. Furthermore, from detailed analysis of the UV photolysis of MHP, the yield of OH radicals is obtained to be 0.91±0.04. Based on the MHP atmospheric lifetime and the yield of OH radicals, it is concluded that MHP plays an essential role in the redistribution of OH radicals in the troposphere.  相似文献   

7.
顾晨宇 《科技信息》2006,(11):158-159
本文通过中间件技术及其特点,详细论述了中间件演变与发展趋势,同时分析了中间件的面临的一些问题,并总结了现阶段国产中间件的特征。  相似文献   

8.
RFID中间件是RFID系统应用的关键,数据管理算法体现着中间件的智能化程度,是中间件的重要组成部分。传统中间件上数据管理算法的实现直接嵌入到中间件架构,二者的高耦合限制了平台的可扩展性和适用性。以设计实现一种可灵活设置功能组件的层次模型的RFID中间件为基础,提出了数据管理算法组件与中间件平台低耦合的设计,提升了中间件的可扩展性。最后介绍了此设计的一个应用实例。  相似文献   

9.
随着构件复用研究的深入和中间件应用领域的扩大,构件技术及中间件成为目前研究的热点。本文分析构件化软件及中间件的本质,探讨了构件与中间件之间的联系,为构件化软件指导中间件开发提供一条可行途径。  相似文献   

10.
张伟娜 《科技信息》2011,(21):205-206
中间件是一门综合的企业级软件开发技术课程。本文介绍了目前中间件课程教学中存在的问题,就企业级应用与中间件的关系,探索中间件教学方法改革,以提高教学质量,培养学生的职业素质,为实施中间件教学提供一种可行的参考方法。  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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