减压渣油供氢剂减黏裂化研究

减黏裂化作为一种不生成焦炭的热加工方法主要涉及两类化学反应，裂解反应和缩合反应。裂解反应使减压渣油的平均分子量及其胶团直径变小，改善渣油的倾点和黏度；缩合反应使减压渣油及其中间产物中的芳烃、烯烃等缩合成大分子量产物，产生新的胶核，甚至生成焦炭。常规减黏裂化过程中，这两类化学反应主要与反应温度和反应时间有关。在热作用下渣油中的大分子裂解为H／C原子比相对较高的饱和烃自由基和H／C原子比相对较低的芳香性自由基。后者还可失去自身的环烷氢而使其H／C原子比进一步降低。如果体系中有足量的氢化芳烃存在，那么氢化芳烃分子上的活泼氢就可能转移到芳香性自由基的单电子位，将自由基封闭，从而阻止芳香性自由基之间的相互缩合，抑制使分子长大的缩合反应。如果体系中的氢化芳烃含量不足。则热反应体系中就没有足够的活泼氢将芳香性自由基封闭，芳香性自由基缩合反应的几率较高，造成过早地生焦。这种来自渣油分子自身的活泼氢的化学行为与渣油热反应生焦诱导期有一定关系。     

二(三苯基膦)水杨酸铜(Ⅰ)乙醇溶剂配合物的晶体结构

0IntroductionThestudyofcopper?complexesisinvestigatedinmanylaboratories.Amongthereasonsforcarryingouttheinvestigationofsuchspeciesaretheirstructuralfeatures犤1犦,theusefulnessofcopper?compoundsinorganicsyntheses犤2犦andthewell-documentedimpor-tanceofcopper?centersattheactivesitesofanumberofprotein犤3犦.Concerningcopper?carboxy-latesafurtherinterestexists,stemmingfromtheiruseinhomogeheouscatalysedhydrogenation犤4犦.Thecopper?bis(triphenylphosphine)cationisasoft,butflexi-bleacceptorionthatcanacc…     

Influence of hydrogen bonding on the properties of water molecules adsorbed in zeolite frameworks

Three hydrated aluminosilicate frameworks—LiABW, NaNAT, and BaEDI—are partly optimized with the periodic Hartree–Fock CRYSTAL95 code. In particular, we optimized the positions of the adsorbed water molecules including the positions of the framework cations (ABW, NAT) or part of the framework atomic positions (ABW). This allowed us to compare cation–water clusters in the gas and adsorbed states and discuss the influence of hydrogen bonding to the framework oxygen atoms or to the neighbor water molecules on the atomic properties (quadrupole coupling constant, anisotropy of electric field gradient) of the adsorbed water molecules. The LiBIK structure obtained from X‐ray diffraction is also considered to illustrate the hydrogen bonds occurring between adsorbed water molecules. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003     

白酒中C_9－C_（18）脂肪酸的气相色谱分析

白酒中Ｃ＿９－Ｃ＿（１８）脂肪酸的气相色谱分析周在德，曾永昌（四川大学化学系成都６１００６４）关键词气相色谱法，白酒，Ｃ＿９－Ｃ＿（１８）脂肪酸。白酒中脂肪酸的含量及相互比例关系，极大地影响着白酒的色，香，味，风格￣（［１］［２］）。一般采用的化学分...     

{Cu[H_2NC(CH_2OH)_3]_2}{Pic}_2·H_2O的合成与晶体结构

三羟甲基氨基甲烷与苦味酸(Pic)铜在乙醇水混合液中反应,制得少见的不对称氢键连接的超分子化合物{Cu[H2NC(CH2OH)3]2}{Pic}2?H2O。晶体属三斜晶系,空间群为P ,晶胞参数为a = 6.894(1),b = 8.219(1),c = 13.543(3) ? ?= 79.290(1),?= 8 3.36(2), ?= 84.590(1)埃轿狢20H30CuN8O22,V = 746.9(2) 3,Z = 1,Dc = 1.774 g/cm3,F(000) = 411,?= 0.844 mm-1,R = 0.0334,Rw = 0.0863。在配合物的结构单元中, Cu2+位于对称中心,分别与2个四齿配体(三羟甲基氨基甲烷)中的2个OH,1个NH2,三齿配位,呈笼状螯合。而另一个OH,因配体和中心离子构型的限制,不参与配位。     

气相色谱法分析生产过程中的邻甲基苯胺

气相色谱法测定工业生产过程中邻甲基苯胺及其杂质邻硝基甲苯、间甲基苯胺、对甲基苯胺的含量。4种物质的浓度与色谱峰面积呈良好的线性关系,测定结果与标准值基本一致。邻甲基苯胺、邻硝基甲苯、间甲基苯胺、对甲基苯胺的RSD分别为0.0025%、1.4081%、0.9929%、1.1365%,检出限分别为0.065、0.044、0.062、0.056mg/L。     

流动注入吸附溶出—催化极谱氢波分析痕量铂

本文叙述一种流动注入吸附溶出一催化极谱测定痕量铂的新技术,它集中了溶出法、催化波和流动注入的优点,达到非常高的灵敏度和分析速度。实验给出了最佳载液组成、流速、注入体积、吸附富集电位和吸附时间等因素。本方法成功地进行了多种铂络合物、矿样和生物样品分析。     

A supported gold catalyst for the elimination of hydrogen from CO2 feed gas in the production of urea

Supported gold catalyst for eliminating hydrogen from CO₂ feed gas in the production of urea is found to be superior to other industrial catalysts (e.g. Pt/Al₂O₃ and PdPt/Al₂O₃) in catalytic activity and resistance to sulfur poisoning.     

Synthesis, X-ray crystal structures, and gas sorption properties of pillared square grid nets based on paddle-wheel motifs: implications for hydrogen storage in porous materials

A systematic modulation of organic ligands connecting dinuclear paddle-wheel motifs leads to a series of isomorphous metal-organic porous materials that have a three-dimensional connectivity and interconnected pores. Aromatic dicarboxylates such as 1,4-benzenedicarboxylate (1,4-bdc), tetramethylterephthalate (tmbdc), 1,4-naphthalenedicarboxylate (1,4-ndc), tetrafluoroterephthalate (tfbdc), or 2,6-naphthalenedicarboxylate (2,6-ndc) are linear linkers that form two-dimensional layers, and diamine ligands, 4-diazabicyclo[2.2.2]octane (dabco) or 4,4'-dipyridyl (bpy), coordinate at both sides of Zn(2) paddle-wheel units to bridge the layers vertically. The resulting open frameworks [Zn(2)(1,4-bdc)(2)(dabco)] (1), [Zn(2)(1,4-bdc)(tmbdc)(dabco)] (2), [Zn(2)(tmbdc)(2)(dabco)] (3), [Zn(2)(1,4-ndc)(2)(dabco)] (4), [Zn(2)(tfbdc)(2)(dabco)] (5), and [Zn(2)(tmbdc)(2)(bpy)] (8) possess varying size of pores and free apertures originating from the side groups of the 1,4-bdc derivatives. [Zn(2)(1,4-bdc)(2)(bpy)] (6) and [Zn(2)(2,6-ndc)(2)(bpy)] (7) have two- and threefold interpenetrating structures, respectively. The non-interpenetrating frameworks (1-5 and 8) possess surface areas in the range of 1450-2090 m(2)g(-1) and hydrogen sorption capacities of 1.7-2.1 wt % at 78 K and 1 atm. A detailed analysis of the sorption data in conjunction with structural similarities and differences concludes that porous materials with straight channels and large openings do not perform better than those with wavy channels and small openings in terms of hydrogen storage through physisorption.     

天花粉蛋白的化学——Ⅴ.粉末状结晶天花粉蛋白的拉曼光谱

本文报道粉末状结晶天花粉蛋白的拉曼光谱。酰胺Ⅰ和酰胺Ⅲ的振动谱带在1680和1250 cm~(-1)。骨架C_α—C—N的振动谱带在965 cm~(-1)。苯丙氨酸残基的特征谱带在1010和1620 cm~(-1)。酪氨酸残基的特征谱带在845和862 cm~(-1)。色氨酸残基的特征谱带在765 cm~(-1)。酰胺Ⅰ和Ⅲ的谱带中,B折叠和无序结构的特征较为明显。表征无序结构的965 cm~(-1)谱带很弱。