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用能量转移探测萘-蒽二元分子体系的构象变化
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作者 江华 许慧君 《物理化学学报》 SCIE CAS CSCD 北大核心 2001年第12期1092-1096,共5页
合成了一个带有末端取代的能量给体-萘和能量受体-蒽的开链冠醚(DSA).吸收光谱表明两个发色团之间在基态时没有相互作用 选择性激发萘观察到萘的荧光强度下降,同时伴随着蒽的发射增强,表明发生了从萘至蒽的单重态-单重态能... 合成了一个带有末端取代的能量给体-萘和能量受体-蒽的开链冠醚(DSA).吸收光谱表明两个发色团之间在基态时没有相互作用 选择性激发萘观察到萘的荧光强度下降,同时伴随着蒽的发射增强,表明发生了从萘至蒽的单重态-单重态能量转移.能量转移效率受溶剂极性的影响.可以认为在极性小的溶剂如苯中-OCH2CH2O-单元中的中心C—C键主要以反式存在,而在极性大的溶剂如乙腈中则以邻交叉式为主.因此,开链冠醚末端取代的萘和蒽之间的距离随着溶剂极性的增大,能量转移效率却随之降低.表明能量转移可以用于探测以柔性配体键连接的给体-受体体系在不同极性溶剂中的构象变化特性. 展开更多
关键词 能量转移 构变变化 溶剂 开链冠醚 极性 二元分子体系 聚乙二醇
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不同链长二元分子卟啉酞菁(TTP-O-(CH_2)_n-O-Pc的三阶光学非线 被引量:3
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作者 刘志斌 张新夷 +5 位作者 田宏健 许慧君 周庆复 艾希成 张岩 费浩生 《发光学报》 EI CAS CSCD 北大核心 1994年第3期233-236,共4页
利用简并四波混频(DFWM)方法测量二元分子卟啉酞菁的三阶非线性极化系数X(3)值.得到二元分子卟啉酞菁的x(3)值比它们单元分子卟啉、酞菁的x(3)值大;二元分子卟啉酞菁的x(3)值起初是随链长的增加而增加,链长增... 利用简并四波混频(DFWM)方法测量二元分子卟啉酞菁的三阶非线性极化系数X(3)值.得到二元分子卟啉酞菁的x(3)值比它们单元分子卟啉、酞菁的x(3)值大;二元分子卟啉酞菁的x(3)值起初是随链长的增加而增加,链长增至n=3时,x(3)值达到最大值.当链长进一步增加时,二元分子卟啉酞菁的x(3)值反而下降.这同二元分子中卟啉、酞菁分子由柔性链连接有关.本文对结果给出可能的解释. 展开更多
关键词 二元分子 卟啉 酞菁 非线性光学
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生物质多元醇选择性催化氢解制小分子二元醇研究进展 被引量:4
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作者 刘琪英 廖玉河 +3 位作者 石宁 王铁军 马隆龙 张琦 《化工进展》 EI CAS CSCD 北大核心 2013年第5期1035-1042,1182,共9页
乙二醇、1,2-/1,3-丙二醇等小分子二元醇在精细和有机化工、生物医药等领域应用广泛。与石化路径相比,以可再生的生物质多元醇(丙三醇、山梨醇/木糖醇)为原料选择性催化氢解制取上述小分子二元醇具有过程简单、绿色高效等显著优势,已成... 乙二醇、1,2-/1,3-丙二醇等小分子二元醇在精细和有机化工、生物医药等领域应用广泛。与石化路径相比,以可再生的生物质多元醇(丙三醇、山梨醇/木糖醇)为原料选择性催化氢解制取上述小分子二元醇具有过程简单、绿色高效等显著优势,已成为生物质催化转化的研究热点。本文综述了典型生物质多元醇山梨醇/木糖醇和丙三醇选择性催化氢解为乙二醇、1,2-/1,3-丙二醇等小分子二元醇,重点阐述了丙三醇选择性氢解制1,2-丙二醇、1,3-丙二醇和山梨醇/木糖醇选择性氢解制小分子二元醇的催化剂体系和反应机理,并对该领域的发展前景作了展望,提出开发高效稳定的催化剂体系和工艺是未来的研究重点。 展开更多
关键词 山梨醇 木糖醇 丙三醇 选择性氢解 分子二元
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二元小分子醇/盐双水相体系萃取三唑类杀菌剂 被引量:4
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作者 吴格格 高仕谦 张占恩 《现代化工》 CAS CSCD 北大核心 2020年第2期231-235,共5页
应用二元小分子醇-盐双水相微萃取(ATPS)技术,建立水体中6种三唑类杀菌剂的高效液相色谱(HPLC)分析方法,观察了二元小分子醇体积比、盐的种类和浓度、萃取时间、样品溶液p H和萃取温度对萃取效率的影响,6种三唑类杀菌剂的相关系数(R)在0... 应用二元小分子醇-盐双水相微萃取(ATPS)技术,建立水体中6种三唑类杀菌剂的高效液相色谱(HPLC)分析方法,观察了二元小分子醇体积比、盐的种类和浓度、萃取时间、样品溶液p H和萃取温度对萃取效率的影响,6种三唑类杀菌剂的相关系数(R)在0. 999 3~0. 999 9;检出限为1. 67~2. 96μg/L(S/N=3)。将该方法应用于苏州地区的河水、自来水和稻田水实际水样的分析,得到加标回收率范围在81. 9%~106. 9%,相对标准偏差为1. 7%~8. 1%。本方法具有简单快速的操作和低检出限,可满足环境水样中痕量三唑类杀菌剂残留的分析。 展开更多
关键词 二元分子醇-盐双水相微萃取 高效液相色谱法 三唑类杀菌剂 环境水样
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南京市大气气溶胶中二元羧酸昼夜变化研究 被引量:14
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作者 牛红云 陈洁 +2 位作者 王格慧 高士祥 王连生 《环境科学研究》 EI CAS CSCD 北大核心 2005年第6期23-26,共4页
2002年3月14-19日在南京大学校园内进行了为期1周的采样,用以研究大气气溶胶PM2 5中的低分子量(C2~C10)二元羧酸的昼夜变化规律.结果表明,南京市大气气溶胶中二元羧酸的夜间质量浓度(平均为460ng/m3)普遍高于相应的白天质量浓度(平均为... 2002年3月14-19日在南京大学校园内进行了为期1周的采样,用以研究大气气溶胶PM2 5中的低分子量(C2~C10)二元羧酸的昼夜变化规律.结果表明,南京市大气气溶胶中二元羧酸的夜间质量浓度(平均为460ng/m3)普遍高于相应的白天质量浓度(平均为350 ng/m3).草酸是含量最高的二元羧酸,其次是丁二酸与丙二酸,这3种二元羧酸占所检测到的水溶性有机酸总量的89%.由C3/C4(ρ(丙二酸)/ρ(丁二酸))(平均为1.00)可以判断采样期间气溶胶中有机酸主要来源于大气的光化学氧化反应,从C6/C9(ρ(己二酸)/ρ(壬二酸))(平均为0.88)可以认为生物源是有机酸的一个重要来源. 展开更多
关键词 大气气溶胶 分子二元羧酸 昼夜变化规律 C3 C4 C6/C9
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电场作用下二元高分子共混体系微观组织演化的相场模拟
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作者 邢文琪 覃众垚 +1 位作者 郭建超 张刚 《高校化学工程学报》 EI CAS 2024年第6期963-970,共8页
高分子复合材料具有单个高分子材料所不具备的优异性能。为探究电场作用下二元高分子共混体系微观组织演化及动力学过程,基于形貌和各向异性参数,采用相场法进行了数值模拟。采用高精度的半隐式傅立叶谱法,求解修改的非线性Cahn-Hilliar... 高分子复合材料具有单个高分子材料所不具备的优异性能。为探究电场作用下二元高分子共混体系微观组织演化及动力学过程,基于形貌和各向异性参数,采用相场法进行了数值模拟。采用高精度的半隐式傅立叶谱法,求解修改的非线性Cahn-Hilliard-Cook (CHC)扩散方程。模拟结果表明,外加电场对高分子共混体系相分离的微观组织及动力学过程有着显著影响。在外加电场作用下,随着时间进行,各向异性参数逐渐增大,最终达到稳定,并且电场越强,各向异性参数的初始值越大。此外,体系的初始成分对电场取向的动力学过程影响显著,尤其对具有临界成分的体系,电场的取向作用更强且更显著。最后,研究揭示了电场对高分子共混物相分离过程的作用机理。研究结论有助于设计并指导合成具有各向异性微观结构及优异性能的高分子复合材料。 展开更多
关键词 电场 二元分子共混体系 相分离 相场模拟 微观组织
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非线性光学材料与器件
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《中国光学》 EI CAS 1995年第3期44-46,共3页
O437 95031710不同链长二元分子卟啉酞菁(TTP-O(CH<sub>2</sub>)。-O-Pc)的三阶光学非线性研究=Studies on third—order optical nonlinearity in porphyrinph-thalocyanine heterodimers(TTP—O(CH<sub>2<... O437 95031710不同链长二元分子卟啉酞菁(TTP-O(CH<sub>2</sub>)。-O-Pc)的三阶光学非线性研究=Studies on third—order optical nonlinearity in porphyrinph-thalocyanine heterodimers(TTP—O(CH<sub>2</sub>)。—O—Pc)with different chain lengths[刊,中]/ 展开更多
关键词 非线性光学材料 非线性光学性质 晶体 光折变 二元分子卟啉酞菁 三阶光学非线性 工业大学 空间电荷场 稀土配合物 中科院
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非线性光学效应与应用
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《中国光学》 EI CAS 1997年第2期41-42,共2页
O437 97021004光折变空间孤子的研究=Theory and experimentalobservation of photorefractive spatial soliton[会,中]/李智红,董孝义,盛秋琴,张海宁,金宏发,张艺兵(南开大学现代光学研究所.天津(300071))//全国第七次光纤通信学术会议... O437 97021004光折变空间孤子的研究=Theory and experimentalobservation of photorefractive spatial soliton[会,中]/李智红,董孝义,盛秋琴,张海宁,金宏发,张艺兵(南开大学现代光学研究所.天津(300071))//全国第七次光纤通信学术会议.—广西.桂林,95.11介绍了对光折变空间孤子理论研究和实验观察、并展望了它的应用发展前景。参4(严兰)O437//TN253 展开更多
关键词 光折变空间孤子 光纤通信 三阶光学非线性 应用发展前景 非线性光学效应 理论研究 光折变效应 实验观察 二元分子 学术会议
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A universal thermodynamic model of calculating mass action concentrations for structural units or ion couples in aqueous solutions and its applications in binary and ternary aqueous solutions 被引量:1
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作者 杨学民 赵伟洁 +2 位作者 柴国明 郭汉杰 张强 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第3期626-641,共16页
A universal thermodynamic model of calculating mass action concentrations for structural units or ion couples in ternary and binary strong electrolyte aqueous solution was developed based on the ion and molecule coexi... A universal thermodynamic model of calculating mass action concentrations for structural units or ion couples in ternary and binary strong electrolyte aqueous solution was developed based on the ion and molecule coexistence theory and verified in four kinds of binary aqueous solutions and two kinds of ternary aqueous solutions. The calculated mass action concentrations of structural units or ion couples in four binary aqueous solutions and two ternary solutions at 298.15 K have good agreement with the reported activity data from literatures after shifting the standard state and concentration unit. Therefore, the calculated mass action concentrations of structural units or ion couples from the developed universal thermodynamic model for ternary and binary aqueous solutions can be applied to predict reaction ability of components in ternary and binary strong electrolyte aqueous solutions. It is also proved that the assumptions applied in the developed thermodynamic model are correct and reasonable, i.e., strong electrolyte aqueous solution is composed of cations and anions as simple ions, H2O as simple molecule and other hydrous salt compounds as complex molecules. The calculated mass action concentrations of structural units or ion couples in ternary and binary strong electrolyte aqueous solutions strictly follow the mass action law. 展开更多
关键词 universal thermodynamic model mass action concentration activity ternary aqueous solution binary aqueous solution ion and molecule coexistence theory structural units ion couples components
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Density, Viscosity, and Excess Properties for Binary Mixture of Diethylene Glycol Monoethyl Ether + Water from 293.15 to 333.15 K at Atmospheric Pressure 被引量:5
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作者 李新学 徐国民 +1 位作者 王彦伟 胡一江 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第6期1009-1013,共5页
Densities and viscosities were measured as a function of composition for binary liquid mixture of diethylerie glycol monoethyl ether [CH3CH2O(CH2)2O(CH2)2OH] + water from 293.15 to 333.15 K at atmospheric pressur... Densities and viscosities were measured as a function of composition for binary liquid mixture of diethylerie glycol monoethyl ether [CH3CH2O(CH2)2O(CH2)2OH] + water from 293.15 to 333.15 K at atmospheric pressure, with a capillary pycnometer and Ubbelohde capillary viscometer respectively. From the experimental data, the excess molar volume V^E, viscosity deviation △η, and the excess energy of activation for viscous flow △G^*E were calculated. These data were correlated by the Redlich-Kister type equations to obtain the coefficients and standard deviations. The results showed a strong molecular interaction between diethylene glycol monoethyl ether and water. 展开更多
关键词 DENSITY VISCOSITY diethylene glycol monoethyl ether binary mixture excess molar volume viscosity deviation
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The Applicability of the Density Rule of Pathwardhan and Kumer and the Rule Based on Linear Isopiestic Relation 被引量:1
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作者 胡玉峰 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2001年第3期319-321,共3页
The applicability of the density rule of Pathwardhan and Kumer and the rule based on the linear isopiestic relation is studied by comparison with experimental density data in the literature. Predicted and measured val... The applicability of the density rule of Pathwardhan and Kumer and the rule based on the linear isopiestic relation is studied by comparison with experimental density data in the literature. Predicted and measured values for 18 electrolyte mixtures are compared. The two rules are good for mixtures with and without common ions, including those containing associating ions. The deviations of the rule based on the linear isopiestic relation are slightly higher for the mixtures involving very strong ion complexes, but the predictions are still quite satisfactory.The density rule of Pathwardhan and Kumer is more accurate for these mixtures. However, it is not applicable for mixtures containing non-electrolytes. The rule based on the linear isopiestic relation is extended to mixtures involving non-electrolytes. The predictions for the mixtures containing both electrolytes and non-electrolytes and the non-electrolyte mixtures are accurate. All these results indicate that this rule is a widely applicable approach. 展开更多
关键词 binary density rules DENSITY apparent molar volume multicomponent system binary sub-system
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Evolutionary Computation for Realizing Distillation Separation Sequence Optimization Synthesis 被引量:2
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作者 Dong Hongguang Qin Limin Wang Kefeng Yao Pingjing 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2005年第4期52-59,共8页
Evolutionary algorithm is applied for distillation separation sequence optimization synthesis problems with combination explosion. The binary tree data structure is used to describe the distillation separation sequenc... Evolutionary algorithm is applied for distillation separation sequence optimization synthesis problems with combination explosion. The binary tree data structure is used to describe the distillation separation sequence, and it is directly applied as the coding method. Genetic operators, which ensure to prohibit illegal filial generations completely, are designed by using the method of graph theory. The crossover operator based on a single parent or two parents is designed successfully. The example shows that the average ratio of search space from evolutionary algorithm with two-parent genetic operation is lower, whereas the rate of successful minimizations from evolutionary algorithm with single parent genetic operation is higher. 展开更多
关键词 evolutionary algorithm coding method based on the binary tree crossover operator mutation operator distillation separation sequence optimization synthesis
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Green Process for Synthesis of Zeolite with MFI Structure
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作者 Yin Xiping 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2005年第2期33-36,共4页
A clean and environmentally friendly new process for synthesis of zeolite with MFI structure was presented. This process through recycling of vented gas and mother liquor can reduce or avoid discharge of nitrogen-cont... A clean and environmentally friendly new process for synthesis of zeolite with MFI structure was presented. This process through recycling of vented gas and mother liquor can reduce or avoid discharge of nitrogen-containing offgas and waste liquid without affecting the physical and chemical properties of synthetic zeolite, leading to green synthesis of zeolite. This process can help to cut corners on production cost to achieve the sustainable development. 展开更多
关键词 MFI ZEOLITE green SYNTHESIS
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Influence of Water Vapor on Silica Membrane: Adsorption Properties and Percolation Effect
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作者 Chun-lin Song Gang Liu 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2015年第3期345-350,I0002,共7页
The influence of water vapor on silica membrane with pore size of ,-4A has been investigated in terms of adsorption properties and percolation effect at 50 and 90 ℃. Two methods are employed: spectroscopic ellipsome... The influence of water vapor on silica membrane with pore size of ,-4A has been investigated in terms of adsorption properties and percolation effect at 50 and 90 ℃. Two methods are employed: spectroscopic ellipsometry for water vapor adsorption and gas permeation of binary mixture of helium and H2O The adsorption behaviors on the silica membrane comply with the first-order Langmuir isotherm. The investigation demonstrates that helium flux through the silica membrane decreases dramatically in presence of H20 molecules. The transport of gas molecules through such small pores is believed not to be continuous any more, whereas it is reasonably assumed that the gas molecules hop from one occupied site to another unoccupied one under the potential gradient. When the coverage of H20 molecules on the silica surface increases, the dramatic decrease of helium flux could be related to percolation effect, where the adsorbed H20 molecules on the silica surface block the hopping of helium molecules. 展开更多
关键词 Silica membrane Percolation effect ADSORPTION
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Ultrasonic study on molecular interactions in binary mixtures of formamide with 1-propanol or 2-propanol
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作者 Manju Rani Suman Gahlyan +1 位作者 Ankur Gaur Sanjeev Maken 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第4期689-698,共10页
Ultrasonic speeds have been measured at 298.15 K and 308.15 K for mixtures of formamide + 1 -propanol or 2-propanol. For an equimolar mixture, excess molar compressibility follows the sequence of l-propanol 〉 2-prop... Ultrasonic speeds have been measured at 298.15 K and 308.15 K for mixtures of formamide + 1 -propanol or 2-propanol. For an equimolar mixture, excess molar compressibility follows the sequence of l-propanol 〉 2-propanol. The ultrasonic speed data are correlated by various correlations such as Nomoto's relation, van Dael's mixing relation and impedance dependence relation, and analyzed in terms of Jacobson's free length theory and Schaaffs collision factor theory. Excess isentropic compressibility is calculated from ex- perimental ultrasonic speed data and previously reported excess volume data. The excess molar ultrasonic speed and isentropic compressibility values are fitted to Redlich-Kister polynomial equation. Other proper- ties such as molecular association, available volume, free volume, and intermolecular free length are also calculated. The excess isentropic compressibility data are also interpreted in terms of graph theoretical ap- proach. The calculated isentropic compressibility values are well consistent with the experimental data. It is found that the interaction between formamide and propanol increases when hydroxyl group attached to a carbon atom has more -CH3 groups. 展开更多
关键词 Ultrasonic speedGraph theoretical approachFormamidePropanollntermolecular interaction
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Determination of Transport Properties for Dilute Gas Mixtures Involving Carbon Tetrafluoride
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作者 Mohammad Mehdi Papari Jalil Moghadasi +1 位作者 Soodabeh Nikmanesh Mahmood RezaDehghan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第2期297-305,共9页
In our previous work,we calculated transport properties of pure gaseous polyatomic carbon tetrafluoride(CF4) and five equimolar binary gas mixtures of CF4 with noble gases through inversion technique.The present work ... In our previous work,we calculated transport properties of pure gaseous polyatomic carbon tetrafluoride(CF4) and five equimolar binary gas mixtures of CF4 with noble gases through inversion technique.The present work is a continuation of our studies on determining the transport properties of binary gas mixtures CF4 with some gases including three diatomic molecules CO,N2,and O2,a linear polyatomic CO2,and two non-linear polyatomic molecules SF6 and CH4.The Chapman-Enskog and Vesovic-Wakeham methods as well as inversion procedure are used to determine the viscosities,diffusivities,and thermal conductivities,which deviates from the literature values within 1%,4%,and 5%,respectively. 展开更多
关键词 principle of corresponding states inversion method kinetic theory of gases DIFFUSIVITY thermal conductivity VISCOSITY transport properties
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利用神经网络推算二元混合物体系的过量 被引量:1
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作者 曹益林 宋予民 +4 位作者 王学锋 汤俊明 鲜栋 吕庆 章卢雁 《计算机与应用化学》 CAS CSCD 1998年第4期255-256,共2页
以第一组分的摩尔分数和第二组分分子中碳原子数目的差异来表证二元分子体系,利用具有三层拓扑结构的神经网络模型,推算了28个体系的过量焓,其中内插16个体系,外推12个体系,所有体系的相对误差均在5%左右,最大相对误差为... 以第一组分的摩尔分数和第二组分分子中碳原子数目的差异来表证二元分子体系,利用具有三层拓扑结构的神经网络模型,推算了28个体系的过量焓,其中内插16个体系,外推12个体系,所有体系的相对误差均在5%左右,最大相对误差为7.68%,最小相对误差为2.29%。 展开更多
关键词 二元分子体系 过量焓 神经网络 混合物
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Electron Dispersion in Liquid Alkali and Their Alloys
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作者 Aditya M.Vora 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第7期159-166,共8页
Ashcroft's local empty core (EMC) model pseudopotential in the second-order perturbation theory is used to study the electron dispersion relation, the Fermi energy, and deviation in the Fermi energy from free elect... Ashcroft's local empty core (EMC) model pseudopotential in the second-order perturbation theory is used to study the electron dispersion relation, the Fermi energy, and deviation in the Fermi energy from free electron value for the liquid alkali metals and their equiatomic binary alloys for the first time. In the present computation, the use of pseudo-alloy-atom model (PAA) is proposed and found successful. The influence of the six different forms of the local field correction functions proposed by Hartree (H), Vashishta Singwi (VS), Taylor (T), lehimaru-Utsumi (IU), Farid et al. (F), and Sarkar et al. (S) on the aforesaid electronic properties is examined explicitly, which reflects the varying effects of screening. The depth of the negative hump in the electron dispersion of liquid alkalis decreases in the order Li --→ K, except for Rb and Cs, it increases. The results of alloys are in predictive nature. 展开更多
关键词 PSEUDOPOTENTIAL Fermi energy electron dispersion curves local field correction functions alkalimetals and their alloys
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荧光素卟啉分子间分子内能量及电子转移反应 被引量:3
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作者 阎晓斌 翁敏 +1 位作者 张曼华 沈涛 《中国科学(B辑)》 CSCD 北大核心 1997年第3期282-288,共7页
合成了以共价键相连的荧光素-卟啉二元分子.研究了荧光素酯与卟啉分子间和分子内的能量及电子转移过程.分子间的荧光猝灭实验表明,当激发荧光素时,荧光素的单重态能量有效地传给卟啉,动态荧光猝灭速度常数(k_d)为1.3×10^(12)s^(-1)... 合成了以共价键相连的荧光素-卟啉二元分子.研究了荧光素酯与卟啉分子间和分子内的能量及电子转移过程.分子间的荧光猝灭实验表明,当激发荧光素时,荧光素的单重态能量有效地传给卟啉,动态荧光猝灭速度常数(k_d)为1.3×10^(12)s^(-1)·mol^(-1)L.吸收光谱和NMR谱结果表明荧光素与卟啉间有基态相互作用,其静态荧光猝灭速度常数(k_s)为3.6×10^(12)s^(-1)·mol^(-1)·L.在二元分子中,当激发荧光素时,从荧光素到卟啉的单重态能量传递效率在0.90以上,速度常数为 1.2×10^(10)S^(-1)·mol^(-1)·L,溶剂极性对其影响不大.当激发卟啉时,在极性溶剂中发生了电子转移,其转移效率为0.51,速度常数为2.3×10~8s^(-1)·mol^(-1)·L. 展开更多
关键词 卟啉 荧光素 能量传递 电子转移 二元分子
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实验测得的C2-C6二元羧酸溶液的冻结温度:冰核核化过程中的重要指标 被引量:1
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作者 杜睿 P. A. Ariya 《科学通报》 EI CAS CSCD 北大核心 2008年第16期1961-1966,共6页
由于大气气溶胶影响着地球辐射总量的平衡与能量的估算,有机化合物作为气溶胶和云凝结核(cloud condensation nuclei,CCN)的重要组成成分,其重要性已经越来越引起科学家们的重视.而低分子量二元羧酸(low molecular weight dicarboxylic ... 由于大气气溶胶影响着地球辐射总量的平衡与能量的估算,有机化合物作为气溶胶和云凝结核(cloud condensation nuclei,CCN)的重要组成成分,其重要性已经越来越引起科学家们的重视.而低分子量二元羧酸(low molecular weight dicarboxylic acids,LMWDCA)作为大气(包括云和雾)中气溶胶的重要成分,其在大气中的传输与转化过程中的作用尤其是对冰核(ice nuclei,IN)核化过程的影响已经成为当前的一个重要的前沿科学研究领域.本研究利用麦吉尔大学的冻结核记数仪分别测量了不同pH的水溶液(超纯净水与自来水)中单纯态的与混合态的低分子量二元羧酸(C2-C6)液滴的冻结温度.结果显示,低分子量二元羧酸(C2-C6)自来水溶液的冻结温度明显的高于其相应的超纯净水溶液.不同混合态的二元羧酸(C2-C6)的纯净水和自来水溶液液滴的平均冻结温度范围分别是:(-24.1±2.8)~(-21.3±3.9)℃和(-10.2±2.2)~(-9.5±2.2)℃,而所测对照水(超纯净水与自来水)溶液液滴的平均冻结温度则分别是(-22.6±3.5)和(-11.2±2.4)℃.C2-C6二元羧酸的加入对于水溶液液滴的冻结温度增高的促进作用并不显著. 展开更多
关键词 冻结温度 分子二元羧酸 冻结核记数仪 水溶液液滴
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