咪唑类脯氨酸离子液体水溶液体积性质

在298.15～323.15 K的温度范围内,分别测定了1-丁基-3-甲基咪唑脯氨酸盐[C4mim][L-Pro]、1-己基-3-甲基咪唑脯氨酸盐[C6mim][L-Pro]和1-辛基-3-甲基咪唑脯氨酸盐[C8mim][L-Pro]这3种咪唑类脯氨酸离子液体与水组成的二元混合溶液在全部组成范围内的密度,计算了混合溶液的过量摩尔体积和无限稀释偏摩尔体积,并用相关经验公式进行了拟合。结果表明,混合溶液的密度均随温度的升高而线性减小;当温度和组成一定时,混合溶液的密度随离子液体阳离子上烷基链长度的增加而减小;3种混合溶液的过量摩尔体积均为负值;在相同温度下,3种离子液体和水的无限稀释偏摩尔体积均小于纯离子液体和纯水的摩尔体积,并且下降幅度随离子液体烷基链长度的增加而减小。     

几种醇类水溶液表面张力的实验研究

采用Wilhelmy吊片法测量了不同浓度下异丙醇、正丁醇、正戊醇水溶液在25℃到65℃温度范围内的表面张力值.结果显示,在适当的浓度下,当温度超过某确定值时,被测溶液的表面张力随温度升高而增大,并且随着醇类中碳原子个数的增加,这种现象更为明显.     

咪唑二氰胺类离子液体在白色发烟硝酸中自燃特性的实验研究

利用滴落实验台在常温常压下对5种咪唑二氰胺类离子液体进行了点火测试实验,研究了咪唑二氰胺类离子液体在白色发烟硝酸中的自燃过程,并分析了阳离子的化学结构与液滴碰撞速度对咪唑二氰胺类离子液体自燃特性的影响。结果显示：1-烯丙基-3-甲基咪唑二氰胺([AMIM][DCA])、1-乙基-3-甲基咪唑二氰胺([EMIM][DCA])和1-丁基-3-甲基咪唑二氰胺([BMIM][DCA])的自燃过程包含3个阶段,即液滴与WFNA的接触、混合与扩散阶段,反应放热、发生微型爆炸阶段以及温度升高、自燃现象产生阶段;1-己基-3-甲基咪唑二氰胺([HMIM][DCA])和1-辛基-3-甲基咪唑二氰胺([OMIM][DCA])的自燃性能较差,微爆现象不再明显。在同一碰撞速度下,微爆延迟时间和点火延迟时间随着阳离子中侧链长度的增加而增大;黏度相差不大时,侧链中不饱和程度增加,微爆延迟时间和点火延迟时间将会缩短。对于同一种离子液体而言,微爆延迟时间和点火延迟时间则随着碰撞速度的增大逐渐减小。微爆延迟时间和点火延迟时间二者呈线性正相关,[AMIM][DCA]、[EMIM][DCA]和[BMIM][DCA]这3种离...     

萘-乙醇及萘-正庚烷体系的密度、黏度测定与关联

利用比重瓶和乌氏黏度计,分别测定了萘-乙醇体系(294.15～333.15K)和萘-正庚烷体系(294.15～339.15K)在不同组成下的密度与黏度。结果表明:在测定范围内,密度与黏度均随着温度的升高而降低,随着萘质量摩尔浓度的增大而增大,同时也计算了萘-乙醇体系和萘-正庚烷体系的表观摩尔体积和极限偏摩尔体积。结果表明:不同温度下的密度和黏度数据与组成的关系,均可用Vogel-Tamman-Fulcher(VTF)方程进行关联回归。本文结果为实际工程设计提供了参考依据。     

手性离子液体1-丁基-3-甲基-咪唑乳酸盐及其与水二元混合物的体积性质和表面性质

在293.15~343.15 K和常压下对手性离子液体1-丁基-3-甲基-咪唑乳酸盐的密度和表面张力进行了测定,并根据密度和表面张力对其体积性质和表面性质进行了计算;在298.15~318.15 K和常压下,对离子液体1-丁基-3-甲基-咪唑乳酸盐与水二元混合物的密度和表面张力在全摩尔浓度范围内进行了测定。在此基础上,对二元混合体系的过量摩尔体积进行了计算,根据Redlich-Kister方程对其进行了拟合,并对体系的热膨胀系数、偏摩尔体积、过量偏摩尔体积以及离子液体和水的表观摩尔体积进行了讨论,对二元混合物的表面性质进行了计算。     

热处理对聚萘酯聚集态结构的影响

用计算机分峯法分解了不同热处理温度的聚萘酯(PEN—2.6)x射线衍射谱,由密度与结晶度囘归直线外推到结晶度100％和0％的密度值与文献[1][1]一致。PEN—2.6的结晶度随热处理温度的升高而增加。非晶区相邻大分子间的平均距离在温度不高时,随热处理温度升高而减小。     

金属络合阴离子型离子液体的合成、性能及对CO_2的捕集

以1-丁基-3-甲基咪唑阳离子([Bmim]+)型离子液体[Bmim]X(X=Cl,Ac)和等物质的量的无机盐AXn(A=Fe,Zn)为原料,通过一步法合成了金属络合阴离子型离子液体[Bmim][AXn+1],测定了离子液体在不同温度下的密度和黏度,采用经验模型关联了密度、黏度与温度的关系,对比研究了CO2气体在[Bmim]X和[Bmim][AXn+1]中的溶解度。[Bmim]X和[Bmim][AXn+1]的密度和黏度均随温度升高而下降,金属络合阴离子型离子液体[Bmim][AXn+1]的密度远远大于对应的传统离子液体[Bmim]X的密度。[Bmim][ZnCl3]和[Bmim][Zn(Ac)3]的黏度远远高于对应的[Bmim]Cl和[Bmim]Ac的黏度,但[Bmim][FeCl4]的黏度远低于对应的[Bmim]Cl的黏度。金属络合阴离子型离子液体[Bmim][AXn+1]吸收CO2的能力显著提高。     

[Bmim]BF_4-H_2O体系超额摩尔体积测定及关联

合成并表征离子液体1-丁基-3-甲基咪唑四氟硼酸盐([Bmim]BF4),测定[Bmim]BF4-H2O二元混合物在不同温度下的密度值和超额摩尔体积.结果表明,在所有组成范围内,体系的超额摩尔体积都为正值,且不同温度下的等温线都存在一极大值点;同时,所有等温线的极值点所对应的H2O的摩尔分数基本上在50%左右.不同温度下超额摩尔集体的变化趋势相似,而在组成相同的情况下,随着温度的增加,超额摩尔体积变大.采用Redlich-Kister方程对[Bmim]BF4-H2O的超额摩尔体积进行关联,最大标准偏差为1.32%.     

配合物谷氨酸锌水溶液表面性质研究

本文报到了，采用滴体积法测定表面张力的实验手段，测定了配合物谷氨酸锌水溶液的表面张力，研究了该配合物水溶液的表面性质，得出了谷氨酸锌配合物水溶液的表面张力随着谷氨酸锌的浓度增加而增大，Ｇｉｂｂｓ表面吸附量是负值，表面张力随温度升高而降低的结论，并从理论上进行了分析与探讨。     

1,2-二甲基-3-丁基咪唑硫酸氢盐离子液体的合成及其性质研究

介绍了在室温下设计合成的一种功能化离子液体1,2-二甲基-3-丁基咪唑硫酸氢盐离子液体[mmBim][HSO4]均为在不同温度下测定了该离子液体的密度、表面张力、粘度和电导率等性质,并根据特定的经验方程,估算了该离子液体的热膨胀系数、标准熵和晶格能等性质参数,为该离子液体的预期应用提供了重要的数据参考.     

［BMIM］HSO4离子液体的热力学性质研究

 在273.2~353.2 K范围内,精确测定了［BMIM］HSO₄离子液体的密度和表面张力。 根据Glasser理论, 讨论了该离子液体的热力学性质, 估算出其晶格能和标准熵。 根据离子液体的空隙模型计算了离子液体的恒压热膨胀系数α= 7.8 × 10^-4 K^-1, 与实验值α = 10.8 ×10^-4 K^-1基本一致。     

离子液体[Emim]Br水溶液的比热容测量及其模型化

在温度为298~343 K,质量分数为10%~90%的条件下,使用BT2.15型Calvet微量量热仪测定了离子液体[Emim]Br水溶液的定压比热容数据,并建立了体系的比热容与温度和浓度的经验关联式,拟合的平均偏差为0.42%。通过比热容实验数据,计算了溶液体系的超额摩尔比热容,发现相对于理想溶液呈正偏差,并随着浓度和温度的增加而增大。     

双阳离子型离子液体[C4(MIM)2][PF6]2的比热容测定及其模型化

利用差示扫描量热计(DSC)测定了双阳离子型离子液体1,1′-(丁烷-1,4-二基)-双(3-甲基-1H-咪唑鎓-1-基)双六氟磷酸盐([C4(MIM)2][PF6]2) 在293.15～513.15 K 温区内的摩尔比热容。结果表明,在 293.15～363.15 K 和 398.15～513.15 K 温区内,该化合物无相变及其他热异常现象发生,比热容随温度变化符合二次方程。在 363.15～398.15 K 温区内,该物质发生固-液熔化相变,其熔化温度、熔化焓及熔化熵分别为 384.71 K、28.243 kJ/mol 和 73.414 J/（K·mol）。根据热力学函数关系式,计算出 [C4(MIM)2][PF6]2 相对于标准参考温度298.15 K的热力学函数值。采用基团贡献法对液相区的热容进行了估算,结果表明,估算值与实验值符合很好。     

Photoluminescence of fullerene[60] in ultrathin ordered multilayers: The dissociation of molecular aggregation

The aggregation behavior of a substituted fullerene compound, 1-benzyl-2-hydro[60]fullerene (C₆₀-Be), in Z-type ultrathin ordered (e.g. LB) multilayers has been studied by UV-vis absorption, steady state and time-resolved fluorescence spectroscopies. The LB multilayers of pure C₆₀-Be showed J-aggregate formation, characterized by a large red-shift of two absorption peaks (ΔE∼2 098 cm¹ from 260→275 nm and ΔE∼1 076 cm^-1 from 328→340 nm, respectively). The main fluorescence emission bands were found at 710, 646, 603, 600 and 595 nm for pure (C₆₀-Be, mixed C₆₀-Be (molar percentage 50%, 25% and 20%. respectively) multilayers and monomeric C₆₀-Be in solution, respectively. The aggregates were dissociated by mixing with some inert materials. The fluorescence decay profiles of C₆₀-Be, mixed C₆₀-Be (molar percentage 50%, 25% and 20%, respectively) in LB films could be best-fitted by using a bi-exponential decay model.     

Thermal expansion in lead zirconate titanate

The volume anomalies with temperature variations in tin-modified lead zirconate titanate ceramics are investigated. Experimental results show that the volume changes are related to the phase transitions induced with temperature. The magnitude and orientation of crystal volume changes are dependent on the particular phase transition. When antiferroelectrics is transformed to ferroelectrics or paraelectrics the volume expands. Oppositely when ferroelectrics is transformed to antiferroelectrics or paraelectrics the volume contracts. In the transition of antiferroelectric orthorhombic structure to tetragonal structure or ferroelectric low-temperature rhombohedral structure to high-temperature rhombohedral structure, there are also revealed apparent anomalies in the curves of thermal expansion. Among them, the volume strain caused by the transition between antiferroelectrics and ferroelectrics is the biggest in magnitude, and the linear expansion dL/L₀ and the expansion coefficient (dL/L ₀)/dT can reach 2.8 × 10⁻³ and 7.5 × 10⁻⁴ K⁻¹ respectively.     

Self-assembly of N-3-γ-pyridyl Aza[60]fulleroid on Au(111)

Self-assembled monolayers of novel C₆₀ derivative, N-3-γ-pyridyl Aza[60]fulleroid (C₆₀Py), on Au(111) were studied by a scanning tunneling microscope under ultrahigh vacuum (UHV). C₆₀Py molecules were assembled on Au (111) via pyridyl nitrogen-Au interaction. The sole assembly of C₆₀Py molecules on Au (111) only exhibited randoml aggregation of C₆₀Py even the films were annealed at 50 and 105°C. By co-assembling with benzyl mercaptan (BM), the C₆₀PyBM films showed highly dense aggregation, but C₆₀Py assemblies still had disordered structure. After the co-assembled C₆₀Py-BM films were annealed at 50°C, BM molecules were partially desorbed, but the assembly of C₆₀Py remained without obvious change. After the co-assembled C₆₀Py-BM films were further annealed at 105°C, the C₆₀Py monolayers with ordered structure were obtained, while the BM molecules were nearly thoroughly desorbed from the surface. Here, the BM molecules play a key role as a surfactant in the formation of the ordered C₆₀Py monolayer.     

Ferric perchlorate-promoted reaction of [60]fullerene with β-keto esters

The ferric perchlorate-promoted reaction of [60]fullerene (C60) with ethyl 2-methylacetoacetate generates fullerenyl hemiketal as a mixture of trans and cis isomers,while the reaction with ethyl acetoacetate gives a C 60-fused dihydrofuran derivative.A possible reaction mechanism for the formation of these products is proposed.     

Dissolved inorganic carbon and its isotopic differentiation in cascade reservoirs in the Wujiang drainage basin

Three cascade reservoirs, built in different periods of time in the Wujiang drainage basin, were investigated in this study. Samples were taken at the surface and also at 20, 40, 60, 80 m depths in front of the dams in April, July, October of 2006 and January of 2007. Chemical parameters were calculated and the concentrations of dissolved inorganic carbon [DIC] and its isotopic composition （δ613CDIC） were determined. In surface waters, the δ613CDIC values are high in summer and autumn and low in winter and spring, while the DIC concentrations are relatively low in summer and autumn and relatively high in winter and spring. In the water column, the DIC concentrations increase while δ613CDIC values decrease with water depth. DIC in various reservoirs is significantly different in isotopic composition from that in natural rivers, but is close to that in natural lakes. In addition, in surface waters, the δ613CDIC values tend to become lower whereas the nutrition level tends to become higher with increasing age of the reservoirs. The conclusion is that after dam blocking, changes took place in the hydrochemical properties of river water, and the impounding rivers developed toward lakes and swamps. In addition, differentiation in DIC isotopic composition may be used to some extent to trace the evolution process of a reservoir.     

新稀土金属间化合物晶体结构及高温晶格热膨胀性能研究

[目的]研究稀土-过渡族金属合金体系中的新稀土金属间化合物,挖掘稀土合金与化合物的新应用。[方法]利用扫描电子显微镜和能谱仪分析合金样品及其组成物相的成分,采用X射线粉末衍射技术研究和测定新金属间化合物的晶体结构及高温晶格热膨胀性能,并对所研究的新金属间化合物的高温热膨胀性能进行总结分析。[结果]不同的合金元素可以形成结构类型相同的晶体结构,得到了部分新金属间化合物的晶格热膨胀系数,这些新稀土金属间化合物的平均晶格热膨胀系数在10~(-6)到10~(-5)数量级之间,它们的平均单胞体积热膨胀系数也在同一数量级。[结论]化学性质相近的合金元素可以相互替代形成同构型金属间化合物。利用X射线粉末衍射同构法可测定新化合物的晶体结构,该法适用于解析二元、三元乃至多元新化合物的晶体结构。所研究的新稀土金属间化合物的热膨胀系数分别满足其各自所属晶系的热膨胀关系。