煤及油母中常见C—X(X=N,S)的解离能

煤及油页岩中除了碳、氢和氧原子是主要的组成元素外,氮和硫等杂原子大都以C—X(X=N,S)的键合形式存在,在其结构及转化利用中同样发挥重要的作用。认识C—X的解离能,有助于建立氮、硫热解过程中的迁移模型,丰富对煤及油母中常见化学键性质的认识,对发展高效清洁的能源利用技术至关重要。利用双杂化密度泛函方法,系统研究了煤及油母中典型C—X键的解离能(BDE)范围。研究结果表明,煤及油母中常见C—N和C—S键的BDE值范围分别是154.1~55.7 kcal·mol~(-1)和83.0~56.6 kcal·mol~(-1)。在热解过程中,苯硫类自由基以及苯胺类自由基会在初期产生,其次才是巯基、胺类自由基等侧链取代自由基脱落。C—S键的整体BDE值范围比其他类型化学键更低,各类化学键最低BDE值的高低顺序符合O—HC—HC—CC—NC—SC—O的规律,其中,只有当有PhO·生成时,C—SC—O,否则C—OC—S。     

煤液化油馏分蒸发焓的测定方法

蒸发焓是液相物质重要的热力学性质,结合煤液化油窄馏分的特点进行了蒸发焓测定方法的选择,在对蒸发焓的各种测定方法分析总结的基础上,指出了各种方法的使用范围、优缺点及其研究现状,归纳和探索了适合于煤液化油馏分这类复杂混合物的蒸发焓测定方法。     

煤的油团聚化学动力学理论

对煤的油团聚形成过程－用煤粒与分散的液相桥间的碰撞来测定速率,描述油团聚过程的化学动力学,预言油团聚的形成属于二级反应。在建立模型和测定速率方面来评价预言的倾向性。由煤的批处理过程得出不同的操作影响,如液体油的用量、搅拌程度等有关动力学参数,通过实验基础了解来定性团聚过程的的动力学模型。     

煤液化油馏分热力学性质的研究进展

为便于了解煤液化油品的性质,介绍了煤液化油组成的分析方法,详细介绍了煤液化油馏分的密度、分子量、黏度、临界性质、表面张力、蒸气压、蒸发焓和比热等热力学性质测量与估算的方法以及研究进展,可为煤液化工程设计提供参考。     

煤液化油窄馏分饱和蒸气压和蒸发焓的测定及计算

用三次膨胀法对煤直接液化油窄馏分的饱和蒸气压进行了测定。实验结果显示,在同一测试温度下,饱和蒸气压随窄馏分蒸馏温度的升高而降低,相同蒸馏温度下,随测试温度的增大而增大;煤液化轻油馏分与纯物质饱和蒸气压一样,其对数值与温度的倒数呈现出良好的线性关系。同时还对测量数据进行线性回归,并使用克劳修斯-克拉佩龙方程进行了蒸发焓的计算,结果显示,随蒸馏温度的提高,窄馏分的蒸发焓数据呈上升的趋势。     

煤液化油的基本热力学性质测定方法的分析

分析了煤液化油的一些基本热力学性质:比热、蒸汽压、气-液相平衡常数和蒸发焓等,并参考石油基本热力学性质的各种测定方法及关联式计算法,探索研究了煤液化油基本热力学性质的测定方法和关联式计算法,特别是对煤液化油比热、蒸汽压的测定、气-液相平衡常数的计算及蒸发焓的估算作了详尽的讨论.最后得出了测定煤液化油这些热力学性质的适宜方法.简要概括了煤液化油馏分临界性质参数的计算.     

煤液化油窄馏分临界性质的研究(Ⅱ)假临界压力

为考察石油馏分假临界压力的经验关联式对神华煤液化油窄馏分的适用性,对神华煤液化油300℃之前馏分进行实沸点实验,切割成8个窄馏分,利用基团贡献法计算得到110~200℃馏分的假临界压力计算值随着蒸馏温度的升高而增大,200~300℃馏分的假临界压力随着蒸馏温度的升高而减小。采用不同计算关联式得到的窄馏分假临界压力与基团贡献法计算值相比较,由周佩正推荐式得到的假临界压力计算结果优于其他关联式,除150~180、180~200和220~240℃馏分外,其他馏分的假临界压力计算值与基团贡献法计算值的相对误差都在5%之内。     

煤沥青橡胶改质筑路油的老化特征

研究了煤沥青橡胶改质筑路油在加速热老化过程中的性质变化,建立了粘度与温度及针入度与温度的关联式,与石油道路沥青相比,前者的耐老化性要比后者稳定,胶体结构也由溶-凝胶型转变为凝胶型。     

神华煤液化油窄馏分假临界性质的研究(Ⅰ) 假临界温度

对神华煤进行煤炭直接液化实验,将300℃之前的液化生成油切割成8个窄馏分,利用基团贡献法计算得到窄馏分的假临界温度随蒸馏温度升高而升高,且符合线性方程Tc=435.4+1.298t.采用6种不同关联式计算得到的煤液化油窄馏分的假临界温度与基团贡献法的估算值有较好的一致性,相对误差在5%之内,其中采用Watanasiri关联式和日本NEDO法的相对误差在2%之内.     

煤液化油实沸点蒸馏的模拟实验

采用TD200简易蒸馏装置对石油醚和液体石蜡进行了实沸点蒸馏，得到实沸点蒸馏数据，并绘制了实沸点蒸馏曲线和各馏分质量百分数与温度关系曲线，得出主要馏分所在的沸程分别为石油醚64．5℃～68℃，液体石蜡412℃～420℃；同时计算出了二者的平均沸点为65.73℃和404．36℃．这些曲线及数据不仅对石油醚和液体石蜡的组成和使用性能有参考价值，而且这种分析方法为煤液化油的实沸点蒸馏奠定了基础。     

Insight into the strong antioxidant activity of deinoxanthin, a unique carotenoid in deinococcus radiodurans

Deinoxanthin (DX) is a unique carotenoid synthesized by Deinococcus radiodurans, one of the most radioresistant organisms known. In comparison with other carotenoids, DX was proven to exhibit significantly stronger reactive oxygen species (ROS)-scavenging activity, which plays an important role in the radioresistance of D. radiodurans. In this work, to gain deeper insights into the strong antioxidant activity of DX, the parameters characterizing ROS-scavenging potential were calculated by means of quantum chemical calculations. It was found that DX possesses lower lowest triplet excitation energy for its unique structure than other carotenoids, such as β-carotene and zeaxanthin, which endows DX strong potential in the energy transfer-based ROS-scavenging process. Moreover, the H-atom donating potential of DX is similar to zeaxanthin according to the theoretical homolytic O-H bond dissociation enthalpy. Thus, the large number of conjugated double bonds should be crucial for its strong antioxidant activity.     

Synthesis and Evaluation of N,N′-dimethyl-N,N′-dicyclohexyl-Malonamide (DMDCMA) as an Extractant for Actinides

A malonamide based extractant, i.e., N,N′-dimethyl-N,N′-dicyclohexyl-malonamide (DMDCMA) was synthesized in a single step and tested for the extraction of several actinide ions such as Am(III), U(VI), Np(IV), Np(VI), Pu(IV), Pu(VI), etc., from nitric acid medium. The extractant was soluble in phenyltrifluoromethylsulphone (PTMS or FS-13) unless stated otherwise. The effect of various experimental parameters, such as the aqueous phase acidity (0.01–3 M HNO₃), nature of the acid, oxidation states of the metal ions, ligand concentration, nature of the diluent and temperature on the extraction behavior of metal ions was studied. The extracted Am(III) species was determined from slope analysis method as [Am(NO₃)₃(DMDCMA)₂]. The extraction of the metal ions was found to increase with the aqueous phase acidity. The temperature variation studies allowed the calculation of the heat of the two-phase extraction reaction as well as the corresponding extraction constants. These studies revealed that DMDCMA showed good extraction for all the actinide metal ions investigated, and have the advantage of single stage synthesis and easier purification protocol.     

Thermodynamics of dissociation and micellization of sodium, calcium, aluminum, and tin stearates in mixed organic solvents

Sodium, calcium, aluminum, and tin stearates behave as weak electrolytes in dilute solutions (60% benzene + 40% methanol, vol/vol) below the critical micelle concentration, and conductance data can be explained on the basis of Ostwald’s formula and the Debye-Hückel theory of weak electrolytes. Dissociation constants and thermodynamic parameters for dissociation and micellization of these soaps were also evaluated. Micellization was spontaneous and predominant over the dissociation process.     

煤直接液化油中硫氮化合物的类型分布

为研究煤直接液化油中硫氮化合物的类型分布,根据煤直接液化油的特点,采用GC-PFPD和GC-NCD方法分别优化煤直接液化油中硫氮化合物的分析条件,获得了煤直接液化油中硫、氮化合物的组成及含量。结果表明,煤直接液化油中硫主要以苯并噻吩类和二苯并噻吩类化合物存在,两者占原料油中总硫含量的90%以上,是煤直接液化油加工脱硫的主要对象;煤直接液化油中氮主要以五元杂环含氮化合物形式存在,占比32%,主要代表物质是吲哚类和咔唑类化合物,两者占原料中总氮含量的50%左右,是煤直接液化油加工脱氮的主要对象。     

宁东红石湾煤大分子模型构建及量子化学计算

使用工业分析、元素分析、固体核磁（¹³C NMR）、X射线光电子能谱（XPS）、傅里叶变换红外光谱（FT-IR）对宁东红石湾（HSW）煤样进行表征,获得煤样中元素赋存的种类、价态、化学键环境等物质微观结构的关键参数。结果表明HSW煤结构以芳香族为主,占75.96%,桥接芳碳与周碳比为0.315,可知其结构中以萘为主,苯和蒽为辅。氧原子主要以醚氧基（C-O）、羰基（C=O）和羧基（-COO）的形式存在,其中C-O占53.57%。氮原子以吡啶和吡咯的形式存在。苯环的连接方式以三、四取代为主,分别占47.77%、32.97%,脂肪族中环烷烃或脂肪烃-CH₃占优势。确定HSW煤的分子式为C₂₂₁H₁₄₈O₂₈N₂,分子量为3142.32。在此基础上结合计算机辅助实现了二维和三维大分子模型构筑。应用量子化学计算对HSW煤大分子模型进行了优化及核磁共振、红外光谱模拟,验证了所建模型的合理性。最终实现了HSW煤的微观分子结构的实验与量子化学描述。     

General Construction of Amine via Reduction of N=X (X = C,O, H) Bonds Mediated by Supported Nickel Boride Nanoclusters

Amines play an important role in synthesizing drugs, pesticides, dyes, etc. Herein, we report on an efficient catalyst for the general construction of amine mediated by nickel boride nanoclusters supported by a TS-1 molecular sieve. Efficient production of amines was achieved via catalytic hydrogenation of N=X (X = C, O, H) bonds. In addition, the catalyst maintains excellent performance upon recycling. Compared with the previous reports, the high activity, simple preparation and reusability of the Ni-B catalyst in this work make it promising for industrial application in the production of amines.     

Reactions of Si---H to Si---X (X=halogen) bonds at H-terminated Si(111) surfaces in hydrogen halide solutions in the presence of oxidants

The chemical reactivity of Si---H (and SiH₂) bonds at H-terminated Si(111) surfaces immersed in hydrogen halide (HX; X=Cl, Br, and I) solutions has been investigated by measurements of FTIR and XPS spectra and flat-band potentials. The decreases in the intensity of FTIR bands, together with the increases in the surface atomic (X/Si) ratios obtained from XPS spectra, clearly showed that Si---H bonds in the HX solutions changed to Si---X in the presence of oxidants such as dissolved oxygen and I₂. The conclusion was supported by large positive shifts in the flat-band potential of Si(111). The extent of the changes depended on the concentration and oxidizing power of oxidant and the immersion time. On the other hand, the Si---H (and SiH₂) bonds were fairly stable in the HX solutions, which contain no oxidant, showing only slight decreases in amount, less than about 6% after immersion for 10 min. It is discussed that the formation of Si---X bonds occurs through hole injection by an oxidant, followed by nucleophillic attack of halide ions. Spectral changes observed for the Si---H vibration bands are also discussed on the basis of the formation of Si---X bonds.