塔里木原油馏分油临界性质常用计算公式考察

石油馏分的临界性质是重要的热力学性质,常用来确定石油馏分的相状态,并关联和计算其它热力学性质,是石油加工工艺计算所必需的基础数据。早在20世纪20年代,国外已经开始测定和研究石油馏分的临界性质。1936年Roess[1]测定了八种基属原料油100多个石油馏分的临界温度和临界压力,并提出相应的计算式。30年代以来,又陆续发表了一些求定石油馏分临界温度和压力的经验图表及计算式[2～4],其中有些计算方法仍然依据Roess的实测数据。长期以来,在我国的石油炼制及化工设计计算中,主要采用API炼油技术数据手册[2]推荐的图表和经验关联式来求…     

量热法测定固体的比表面

1 前言固体的比表面积是一个重要的物理化学参数.在石油开采中,液-固或气-固的相互作用对采收率有极大的影响.油砂的比表面是油藏工程设计的重要参数.油砂的主要成份为各种金属氧化物的混合物,如能准确测定各氧化物的比表面,则应能准确测定油砂的比表面。常用的固体比表面测定方法有多种,由浸润热或吸附热求算固体的比表面的量热法也经常运用.Groszey认为金属或金属氧化物粉末从稀正丁醇/正庚烷溶液中吸附     

~(13)C-NMR方法研究酚酞聚芳醚酮砜共聚物的序列结构

通过亲核共缩聚合成了一系列酚酞聚芳醚酮砜共聚物和嵌段共聚物 ,并利用1 3C NMR方法研究了共聚物的链结构 ,通过观察酚酞单元中三个位置的季碳原子的化学位移及其相应强度的变化 ,计算共聚物中不同链段的共聚物的组成、平均序列长度和无规度 .结果表明 ,除嵌段共聚物外 ,其它共聚物的无规度均接近 1 ,表明共聚物为无规共聚物 ,而且对三个位置的季碳原子分析均得出了相同的结果 .     

壳聚糖在4种咪唑型离子液体中溶解性的研究

研究、比较了壳聚糖在4种咪唑型离子液体氯化1-丁基-3-甲基咪唑([BMIM]Cl)、1-丁基-3-甲基咪唑醋酸盐([ BMIM] Ac)、1-乙基-3-甲基咪唑醋酸盐([EMIM] Ac)和氯化1-烯丙基-3-甲基咪唑([AMIM] Cl)中的溶解性,提出了可能的溶解机理,并利用红外光谱(FTIR)、热重分析(TGA...     

ABSORPTION AND EMISSION STUDIES OF ELECTRONIC STATES OF N-ARYLBENZAMIDES

Abstract— Absorption and emission spectra of several N-arylbenzamides have been measured. The quantum yields for their fluorescence were found to be dependent on matrix viscosity and temperature. Singlet-triplet splittings for these compounds were determined from their emission spectra and found to be abnormally small for π. π* states (˜ 1500 cm^-1). Indeed, the phosphorescence maxima of N-arylbenzamides occur slightly to the blue relative to their fluorescence maxima. Intersystem crossing efficiencies were determined for several of these compounds and are consistent with S₁→ S ₀ radiationless decay.     

EFFECTS OF TEMPERATURE ON THE VISCOSITY OF NONIONIC MJCELLAR SOLUTION IN THE PRESENCE OF ADDED SALTS

ABSTRACT

The effects of temperature on the viscosity of nonionic surfactant, Triton X-100, in the presence of added salts are presented. It was found that the plots of logarithm of relative viscosity versus 1/T were obtained from the slopes of these plots. The activation free energies (ΔG?) of the viscous flow were obtained from the slopes of these plots. The activation enthalpies ( ΔH?) and the entropies ( ΔS?) for the viscous flow were calculated and the entropic contribution was found to be negligible. The ΔG? and ΔH? were highly dependent on the nature of the positive ions. The greater the effect on the energy of the sphere-to-rod transition, the more strongly ions are bound. The ΔG? is interpreted in terms of the energy required to activate the transition of micellar structure capable of being transformed into rod micelle.     

DETERMINATION OF THERMODYNAMIC AND KINETIC PARAMETERS OF LARGE SCALE CHROMATOGRAPHIC SEPARATION OF SUGAR AND REDUCING SUGAR

The parameter identification model of large scale chromatography separation process is proposed.The phase equilibrium constants and lumped mass transfer coefficients of sugar and reducing sugar adsorption on D1,D2 and D3 resins as well as the axial dispersion coefficients of the fluid through packed columns are determined by means of the pulse-response experiment technique with an inert substance as a tracer and the chromatography measuring technique.The elution curve calculated from these parameters is good agreement with the experimental elution curve.The sensitivity analysis of these parameters is carried out ,and the result shows that the elution curves of chromatography separation are more sensitive to the variations of the phase equilibrium relationship than to the variation of the axial dispersion as well as the lumped mass transfer coefficients.     

THE ORIGIN OF BIOLUMINESCENCE*

Abstract— Primitive luciferases evolved in order to utilize oxygen directly as an electron acceptor at the low oxygen concentrations of the primitive atmosphere. This provided a major selective advantage in the ability to metabolize aromatic molecules and n-alkanes. These strongly exergonic reactions produce product molecules in electronically excited states, from which light emission is possible. The low-level luminescence observed from microsomal extracts, from the action of leukocytes on phagocytized bacteria and from rapidly growing tissues is ascribed to these same exergonic hydroxylase reactions, or to the release during these reactions of superoxide radicals which can initiate chemiluminescent reactions. Bioluminescence is a later secondary adaptation of this oxygenase reaction to signaling for sex, food or escape. The similarity of the reaction pathways is shown in the three bioluminescent systems from which the substrates and products have been identified.     

SYNTHESIS AND CHARACTERIZATION OF POLYBENZOTHIAZOLAMIDES

Aromatic polybenzothiazolamides were prepared by low temperature solution method by condensing the 2, 2'-diarnino-6, 6'-bibenzothiazole with four different acid chlorides in quantitative yield. These polymers were characterized by IR and NMR. Viscosities of these polyamides range from 0.42 to 1 dl/gm. All these polymers were stable upto 300℃in air.     

随星形聚氧化乙烯的分子拓扑形状演变的单层片晶图案

以不同臂(Arm)数的星形聚氧化乙烯(PEO)为对象,系统地研究了其在不同温度下结晶的晶体冰花图案.实验中采用的星形PEO样品,其臂数分别为3,4和8(3-arm-PEO,4-arm-PEO和8-arm-PEO)且每臂的分子量均为5000,线形PEO其分子量为5000.显然,随着星形PEO分子臂数的增加,分子拓扑形状的各向异性不断减小.在单层片晶冰花图案研究中发现,随着结晶温度逐渐向平衡熔点靠近,这些PEO样品的结晶冰花图案具有从树枝状晶体转变为海藻状晶体,然后转变为非规整的紧凑形晶体,最后变成多面晶体的变化规律.对细节的分析进一步表明,随着星形PEO分子臂数的增加,由于分子的各向异性减小,导致冰花状晶体的各向异性程度不断减弱,因此从树枝状晶体到海藻状晶体和从树枝状晶体到多面晶体的转变温度也都逐渐降低.将这些转变温度对臂数作图获得的一张形态相图(morphology diagram)说明了星形PEO结晶图案的分子形状依赖性,也阐明了冰花图案形成的大分子拓扑形状效应.     

燃料电池技术的发展与我国应有的对策

本文介绍了几种主要类型燃料电池的最新进展，基于世界发展趋势和我国具体情况，作者在碱性燃料电池，磷酸型燃料电池，溶融碳酸盐电池和聚合物电解质燃料电池方面提出了相应对策。以促进我国燃料电池的研究与开发。     

聚全氟乙丙烯自由表面的形态结构

用电子显微镜观察了聚全氟乙丙烯试料的自由表面形态结构,指出试料不同,自由表面形态也不同,有的由无规片层组成,有的则由无规和规整两种片层组成,提出了两种片层结构本质的设想,用另一些实验数据支持这种设想,根据设想所推测的试料的力学性能与实测值基本相符。     

标准溶液测量不确定度的评定

对标准溶液测量不确定度进行合理评定，充分估计分析不确定度的来源，从量值检验时考虑到影响不确定度的各种因素，测量方法的不确定度．配制时考虑到影响不确定度的各种因素以及标准溶液的不均匀性和在有效期内的变动性所引起的不确定度等方面进行综合分析，得出其扩展不确定度。并以镍标准溶液为例作实际分析。     

西红花中金属元素的分析

西红花为鸢尾科植物番红花(Crocus sativus L)的干燥柱头.具活血化瘀,凉血解毒,解郁安神等功效.采用原子吸收分光光度法(AAS)测定西红花中部分金属元素的含量,通过对其宏量元素及微量元素含量的测定结果,分析了西红花中金属元素及其生理作用与药用功效之间的关系.随着元素医学的不断发展,金属元素与中药药效关系及对生物体系的作用有待研究.     

O-BENZYLATION OF POLYPHENOLICS. PREPARATION OF 1,2,4-TRIBENZYLOXYBENZENE

The main phenolic by-products in the O-benzylation of 1,2,4-trihydroxy-or 1,2,4-triacetoxybenzene to 1,2,4-tribenzyloxybenzene have been identified as due to incomplete O-benzylation and C-benzylation. In addition, dibenzyldimethylammonium chloride is formed from DMF and benzyl chloride. The main factors controlling these reactions paths are discussed. An efficient procedure for preparing 1,2,4-tribenzyloxybenzene using NaH in DMF is reported.     

3d金属开环夹心化合物的电子结构

本文用EHMO方法研究了3d金属开环夹心化合物的电子结构。计算得到了它们的基态性质。Ti,V,Cr,Fe的理论构象角分别为90°, 90°, 83°和60°, 同实验测定值符合得相当好。并讨论了开环夹心化合物的δ键和构型稳定性的关系。     

DETERMINATION OF THERMODYNAMIC AND KINETIC PARAMETERS OF LARGE SCALE CHROMATOGRAPHIC SEPARATION OF SUGAR AND REDUCING SUGAR

ＤＥＴＥＲＭＩＮＡＴＩＯＮＯＦＴＨＥＲＭＯＤＹＮＡＭＩＣＡＮＤＫＩＮＥＴＩＣＰＡＲＡＭＥＴＥＲＳＯＦＬＡＲＧＥＳＣＡＬＥＣＨＲＯＭＡＴＯＧＲＡＰＨＩＣＳＥＰＡＲＡＴＩＯＮＯＦＳＵＧＡＲＡＮＤＲＥＤＵＣＩＮＧＳＵＧＡＲＬｉＺｈｏｎｇ；ＳｈｕＷｅｎｌｉ；...     

热历史对尼龙1212熔融行为的影响

利用DSC方法研究了不同热历史条件对尼龙1212熔融行为的影响.不同的热历史条件下,在DSC曲线上,观察到尼龙1212产生2个或3个熔融峰,依据聚合物结晶理论,对各峰的来源进行了分析.在160℃下不同温度退火120 min的尼龙1212样品DSC曲线上,低温结晶熔融峰主要由低温结晶形成的一些微晶体或者片晶熔融产生,其晶体完善程度较差,熔融峰值较低,峰面积较小;主熔融峰是由样品在淬火过程中形成的晶体和升温过程中低温结晶形成的晶体的熔融重结晶形成较为完善的晶体熔融所产生,熔融峰值较高,峰面积较大.在不同的升温速率条件下,熔融峰温度有所移动,表明不同升温速率条件下产生的熔融峰的结晶晶型是相同的.在不同结晶时间下结晶,延长结晶时间对较高完善程度晶体的生长有利.在不同温度下依次退火处理的样品,熔融产生两个附加峰,这两个附加峰的峰温都比它们相应的退火温度高,而峰高和峰面积随退火温度降低而减小.根据等温结晶结果,由Hoffman方法确定了尼龙1212的平衡熔融温度为202.8℃.     

SURFACE FUNCTIONALIZED OF NANODIAMONDS

1. INTRODUCTION Generally, the nanoparticles are comprised of metals, metal oxides, semiconductor materials, and polymer. The nanoparticles have highly interesting optical, electronic, and catalytic properties, and they exhibit wide application in the fi…     

聚醚氨酯薄膜表面性质的反相色谱法研究

本文报道了用反相色谱法研究多嵌段聚醚氨酯与几种低分子化合物的相互作用,测定了表征相互作用的热力学参数。结果表明,由ESCA证明表面软段富集的聚醚氨酯的反相色谱行为主要决定于富集层与探针分子的相互作用;苯及几种烷烃和聚醚氨酯的偏摩尔混合热和它的溶度参数与软段组分的溶度参数差值有关。