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Updated Definition of the Three Solvent Descriptors Related to the Van der Waals Forces in Solutions 与溶液中范德华力相关的三种溶剂描述符的更新定义
Pub Date : 2018-01-24 DOI: 10.4236/OJPC.2018.81001
P. Laffort
Innovative viewpoint on the older topic of the van der Waals forces, is of interesting and significant issue to be concerned in both the fields related to the fundamental investigation and thus valuable in guiding the new physiochemical phenomena and processes for both academic research and practical applications. The intermolecular Van der Waals forces involved in solutions have been recently deeply reconsidered as far as the solute side is concerned. More precisely, the solute descriptors (or parameters) experimentally established, have been accurately related to molecular features of a Simplified Molecular Topology. In the present study, an equivalent result is reached on the solvent side. Both experimental parameters have been obtained simultaneously in previous Gas Liquid Chromatographic studies for 121 Volatile Organic Compounds and 11 liquid stationary phases, via an original Multiplicative Matrix Analysis. In that experimental step, five groups of forces were identified, two of hydrogen bonding and three of Van der Waals: 1) dispersion (London), 2) orientation or polarity strictly speaking (Keesom), and 3) induction-polarizability (Debye). At this stage, an attempt of characterization the solvent parameters via the SMT procedure has been limited to those related to the Van der Waals forces, those related to the hydrogen bonding being for now left aside.
关于范德华力这一古老主题的创新观点,在与基础研究相关的两个领域都是一个有趣而重要的问题,因此在指导学术研究和实际应用的新物理化学现象和过程方面很有价值。溶液中涉及的分子间范德华力最近被深入地重新考虑到溶质方面。更准确地说,实验建立的溶质描述符(或参数)已经准确地与简化分子拓扑的分子特征相关。在本研究中,在溶剂方面达到了等效的结果。在之前的121种挥发性有机化合物和11种液体固定相的气相色谱研究中,通过原始的乘法矩阵分析同时获得了这两个实验参数。在该实验步骤中,确定了五组力,其中两组为氢键,三组为范德华力:1)色散(伦敦),2)严格意义上的取向或极性(Keesom),以及3)感应极化率(Debye)。在这个阶段,通过SMT程序表征溶剂参数的尝试仅限于与范德华力有关的那些,与氢键有关的那些现在被搁置一边。
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引用次数: 0
Corrosive Behavior and Physic-Chemical Characterization of Filtration Tanks 滤池的腐蚀行为和物理化学特性
Pub Date : 2017-11-16 DOI: 10.4236/OJPC.2017.74008
Francisco Casanova-del-Angel
Most drinkable water supplied to the public in Mexico City comes from deep wells which extract water from the subsoil. Before being distributed, it is treated in steel filtration tanks. This water must be subject to evaluation through physic-chemical and bacteriological analyses in order to determine its quality. However, doubts always remain over the influence of the components of this water on the corrosive behavior of the filtration tanks. In light of this, this article studies the physic-chemical characterization values of water and presents the results. This has also enabled the analysis of the corrosion speed of filtration tanks components, boilers and water-cooled systems, where incrustations in pipes, obstructions and loss of heat transfer efficiency occur, rendering drinkable water bad tasting and, after some time, causing pitting corrosion although this type of corrosion only causes serious problems in the long term.
墨西哥城提供给公众的大部分饮用水来自深井,这些深井从底土中提取水。在分配之前,它在钢制滤池中进行处理。这种水必须经过理化和细菌学分析,以确定其质量。然而,对于这种水的成分对滤槽腐蚀性能的影响,人们一直存在疑问。鉴于此,本文对水的理化表征值进行了研究,并给出了研究结果。这也使我们能够分析过滤器部件、锅炉和水冷系统的腐蚀速度,在这些地方,管道中会出现结皮、障碍物和传热效率的损失,使饮用水变质,并在一段时间后引起点蚀,尽管这种类型的腐蚀只会导致长期的严重问题。
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引用次数: 1
Many Electron Atoms: Ionization Energies of Transition Elements 多电子原子:跃迁元素的电离能
Pub Date : 2017-07-04 DOI: 10.4236/OJPC.2017.73007
S. Tosto
The paper introduces a theoretical model aimed to calculate the ionization energies of many electron atoms and their ions. The validity of the model, which implements the statistical formulation of the quantum uncertainty to infer a simple formula of ionization energy, has been already proven in a previous paper comparing systematically experimental and calculated values for elements with atomic numbers 2≤Z≤29, whose electron configurations include all ions with numbers ne of electrons 2≤ne≤Z. The present paper enhances and extends the results previously obtained; the approach is now generalized to include even the transition elements and in particular the lanthanides and actinides. The validity of the proposed model is proven examining all experimental data of ionization energies of these elements and their ions available in literature.
本文介绍了一种计算电子原子及其离子电离能的理论模型。该模型采用量子不确定性的统计公式来推断电离能的简单公式,该模型的有效性已经在之前的一篇论文中得到了证明,该模型系统地比较了原子序数为2≤Z≤29的元素的实验值和计算值,这些元素的电子组态包括电子数为2≤ne≤Z的所有离子。本文对已有的结果进行了改进和推广;这种方法现在被推广到甚至包括过渡元素,特别是镧系元素和锕系元素。通过对这些元素及其离子的电离能的所有实验数据的检验,证明了所提出模型的有效性。
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引用次数: 4
Difference in Number of Electrons in Inner Shells of Charged or Uncharged Elements in Organic and Inorganic Chemistry: Compatibility with the Even-Odd Rule 有机化学和无机化学中带电和未带电元素内壳层中电子数的差异:与奇偶规则的相容性
Pub Date : 2017-05-11 DOI: 10.4236/OJPC.2017.72006
G. Auvert
The recently introduced even-odd rule has been shown to successfully represent chemical structures of ions and molecules. While comparing available drawings in the scientific literature with the list of compounds predicted by the even-odd rule, it became however obvious that existing compounds are fewer than expected. Several predicted compounds involving many covalent bonds have apparently never been experimentally observed. Neutral oxygen for instance is expected to have 6 valence electrons, whereas oxygen can only build a maximum of two bonds, as in water. This specificity is observed for elements in the top-right corner of the periodic table. For compounds to contain only single covalent bonds, and thus follow the even-odd rule, further explanations are necessary. The present paper proposes that those specific elements experience a transfer of electrons from the valence shell into the inner shell, making them unavailable for further bonding. These elements will be described as organic, hereby providing a clear and hopefully unifying definition of the term. In opposition, inorganic elements have a constant inner shell no matter their electrical state or the number of bonds they maintain. More than 70 compounds involving 11 elements of the main group are studied, revealing a progression from fully inorganic elements at the left of the periodic table to fully organic elements. The transition between inorganic or organic elements is made of few elements that take an organic form when negatively charged; they are labelled semi-organic. The article concludes that the fully organic elements of the main group are Oxygen and Fluorine, whereas semi-organic elements are more numerous: C, N, S, Cl, Se, Br and I. Thus, the even-odd rule becomes fully compatible with scientific knowledge of compounds in liquid or gaseous phase.
最近引入的奇偶规则已被证明可以成功地代表离子和分子的化学结构。当将科学文献中可用的图纸与奇偶规则预测的化合物列表进行比较时,很明显,现有的化合物比预期的要少。一些预测的涉及许多共价键的化合物显然从未被实验观察到。例如,中性氧预计有6个价电子,而氧最多只能建立两个键,就像在水中一样。这种特殊性是在元素周期表右上角的元素中观察到的。对于只含有单个共价键的化合物,因此遵循奇偶规则,有必要进行进一步的解释。本文提出,这些特定元素经历了电子从价壳层转移到内壳层的过程,使它们无法进行进一步的键合。这些元素将被描述为有机的,从而提供该术语的清晰且有望统一的定义。相反,无机元素无论其电学状态或保持的键数如何,都有一个恒定的内壳层。研究了70多种化合物,涉及主族的11种元素,揭示了从元素周期表左侧的完全无机元素到完全有机元素的过程。无机元素或有机元素之间的过渡是由少数带负电时呈有机形式的元素组成的;它们被标记为半有机的。文章得出结论,主族中的全有机元素是氧和氟,而半有机元素则更多:C、N、S、Cl、Se、Br和I。因此,奇偶规则与液相或气相化合物的科学知识完全兼容。
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引用次数: 4
Kinetic Approach of Iodine Quantification in Dietary Salts 膳食盐中碘定量的动力学方法
Pub Date : 2017-05-11 DOI: 10.4236/OJPC.2017.72003
G. Gbassi, Thodhekes N. S. J. Yao, P. Atheba, M. D. Yéhé, Germain A. Brou, M. Ake, A. Trokourey
Iodization of dietary salt is recommended to prevent and control iodine deficiency disorders. The kinetic study of dietary iodized salt proves to be of interest not only for the determination of the conditions of production of iodine, but also for a good knowledge of the kinetic and thermodynamic parameters of the reaction. In this work, two salt brands were studied and one of them was used for the kinetic study. The kinetic study showed that the reaction proceeded slowly at a medium rate. Since the reaction admits a global order equal to 1, potassium iodide has no influence on this reaction rate. The concentration of iodate ions introduced in the dietary salt is a kinetic parameter that affects the reaction rate. Calculated rate constant was inversely proportional to time. The study has therefore determined experimentally kinetic parameters of the reaction between iodate and iodide ions.
建议膳食盐加碘以预防和控制碘缺乏症。膳食加碘盐的动力学研究不仅对确定碘的生产条件,而且对了解反应的动力学和热力学参数具有重要意义。本文研究了两种盐品牌,其中一种用于动力学研究。动力学研究表明,反应以中等速率缓慢进行。由于反应的总阶等于1,所以碘化钾对反应速率没有影响。膳食盐中碘离子的浓度是影响反应速率的动力学参数。计算出的速率常数与时间成反比。因此,本研究通过实验确定了碘酸盐和碘化物离子之间反应的动力学参数。
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引用次数: 2
Simplified Coarse-Grained Dynamic Model for Real Gases 真实气体的简化粗颗粒动力学模型
Pub Date : 2017-05-11 DOI: 10.4236/OJPC.2017.72005
P. G. Papadopoulos, C. Koutitas, Yannis N. Dimitropoulos, E. Aifantis
A simplified model is proposed for an easy understanding of the coarse-grained technique and for achieving a first approximation to the behavior of gases. A mole of a gas substance, within a cubic container, is represented by six particles symmetrically moving. The impacts of particles on container walls, the inter-particle collisions, as well as the volume of particles and the inter-particle attractive forces, obeying a Lennard-Jones curve, are taken into account. Thanks to the symmetry, the problem is reduced to the nonlinear dynamic analysis of a SDOF oscillator, which is numerically solved by a step-by-step time integration algorithm. Five applications of proposed model, on Carbon Dioxide, are presented: 1) Ideal gas in STP conditions. 2) Real gas in STP conditions. 3) Condensation for small molar volume. 4) Critical point. 5) Iso-kinetic energy curves and iso-therms in the critical point region. Results of the proposed model are compared with test data and results of the Van der Waals model for real gases.
为了便于理解粗粒度技术并实现气体行为的第一近似,提出了一个简化模型。在一个立方体容器中,气体物质的摩尔数由六个对称运动的粒子表示。考虑了粒子对容器壁的影响、粒子间碰撞、粒子体积和粒子间吸引力,遵循Lennard-Jones曲线。由于对称性,该问题被简化为SDOF振荡器的非线性动力学分析,并通过逐步时间积分算法进行数值求解。介绍了所提出的模型在二氧化碳方面的五个应用:1)STP条件下的理想气体。2) STP条件下的实际天然气。3) 小摩尔体积的冷凝。4) 关键点。5) 临界点区域的等动能曲线和等热流。将所提出的模型的结果与实际气体的试验数据和范德华模型的结果进行了比较。
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引用次数: 0
A Comparative Kinetic Study on the Efficacious Permanganate Oxidation of Fluorenes in Perchloric and Sulfuric Acid Media 高锰酸盐在高氯酸和硫酸介质中高效氧化芴的动力学比较研究
Pub Date : 2017-05-11 DOI: 10.4236/OJPC.2017.72004
R. S. Jassas, A. Fawzy, Rami J. Obied, Mohammed A. S. Abourehab, Saleh A. Ahmed
Oxidation kinetics of fluorene (Fl) and its halogenated derivatives, namely, 2,7-dichlorofluorene (Fl-Cl), 2,7-dibromofluorene (Fl-Br) and 2,7-diiodofluorene (Fl-I), by permanganate ion in both perchloric and sulfuric acid media have been investigated using conventional spectrophotometric technique. In both acidic media, the reactions manifested first order kineticsin [permanganate] and less than unit order each in [reductants] and [acid]. Increasing ionic strength had no effect on the oxidation rates. Oxidation rates of fluorenes in perchloric acid were higher than those in sulfuric acid and the order of the oxidation rates was: Fl > Fl-I > Fl-Br > Fl-Cl. Final oxidation products were identified by GC/MS and FT-IR analyses in all cases as 9H-fluorenone derivatives. Reaction constants as well as activation parameters of the second order rate constants were also evaluated.
采用常规分光光度法研究了芴(Fl)及其卤化衍生物2,7-二氯芴(Fl- cl)、2,7-二溴芴(Fl- br)和2,7-二碘芴(Fl- i)在高氯酸和硫酸介质中被高锰酸盐离子氧化的动力学。在两种酸性介质中,[高锰酸盐]的反应均为一级动力学,而[还原剂]和[酸]的反应均低于一级动力学。增加离子强度对氧化速率没有影响。芴在高氯酸中的氧化速率高于在硫酸中的氧化速率,氧化速率顺序为:Fl > Fl- i > Fl- br > Fl- cl。最终氧化产物经GC/MS和FT-IR分析均为9h -芴酮衍生物。计算了反应常数和二级速率常数的活化参数。
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引用次数: 0
A Molecular Description of Superconductivity of Sulfur Hydride and Related Systems under High-Pressure Conditions 高压条件下硫氢化物及其相关系统超导性的分子描述
Pub Date : 2017-01-09 DOI: 10.4236/OJPC.2017.71002
H. Buck
It has been shown that the recently discovered sulfur trihydride (H3S) can be considered as a superconductor with a transition temperature Tc of 203 Kelvin (K) at 155 GigaPascals (GPa). This is the highest Tc value reported for any superconductor. The established superconductivity occurs via the formation of a molecular system with sulfur atoms arranged on a body-centered cubic lattice. It has been generally accepted that the high Tc value is the result of an efficient electron-phonon interaction. The responsible substance formed by H2S under high pressure, may be considered as a compound with H3S stoichiometry creating an impressive network with hydrogens. We will focus on the hydrogen bonding between sulfur and hydrogens demonstrating a symmetrical arrangement. The geometry of the individual radical compound in relation to corresponding systems will be discussed. Ab initio calculations based on a linear three-center two-, three- and four-electron type of bonding clearly visualized in combination with the dynamics of the Van’t Hoff concept, as described by us in various papers, give a good description of this exclusive network. We also discuss the superconductivity of related phosphorus hydrides and focus on the stability and geometrical differences with respect to the H3S system. These differences are significant, demonstrating the diversity in various structures in showing superconductivity.
已经表明,最近发现的三氢化硫(H3S)可以被认为是在155千兆帕斯卡(GPa)下具有203开尔文(K)的转变温度Tc的超导体。这是所有超导体的最高Tc值。建立的超导性是通过形成一个分子系统来实现的,其中硫原子排列在以体为中心的立方晶格上。人们普遍认为,高Tc值是有效的电子-声子相互作用的结果。H2S在高压下形成的负责任物质可以被认为是具有H3S化学计量的化合物,与氢形成了令人印象深刻的网络。我们将重点研究硫和氢之间的氢键,证明它们是对称排列的。将讨论单个自由基化合物相对于相应系统的几何结构。如我们在各种论文中所描述的,基于线性三中心二电子、三电子和四电子键的从头计算,结合Van’t Hoff概念的动力学,清楚地可视化,对这种排他性网络给出了很好的描述。我们还讨论了相关磷氢化物的超导性,并重点讨论了H3S系统的稳定性和几何差异。这些差异是显著的,证明了在显示超导性方面各种结构的多样性。
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引用次数: 1
The Effect of Fabrication Conditions on the Morphology and Photocatalytic Activity of Bismutite Bi 2 O 2 CO 3 Particles 制备条件对铋矿Bi2O2CO3颗粒形貌及光催化活性的影响
Pub Date : 2017-01-09 DOI: 10.4236/OJPC.2017.71001
Hong Hu, Changlong Xiao
In this study, three-dimensional bismutite Bi2O2CO3 nanoparticels (BSC NPs) have been synthesized through a facile hydrothermal treatment under mild conditions. The reaction temperatures and NaOH concentration have a vital influence on the physical and photocatalytic properties of the obtained BSC NPs. The crystal structure, morphology, chemical composition, specific surface area and photoresponse of as-obtained catalysts were characterized by X-ray diffraction, Scanning electron microsprctrosopy, Energy-dispersive spectroscopy, N2 adsorption/desorption isotherms and UV-Vis spectra, respectively. Furthermore, Rhodamine 6G was used as model reaction to evaluate the photocatalytic activity of BSC NPs. As a result, there was no obvious effect of hydrothermal reaction temperature and NaOH concentration on phase structure and UV-visible light response; while the morphology, BET surface area and photoactivity were affected by hydrothermal reaction temperature and NaOH concentration.
在本研究中,在温和的条件下,通过简单的水热处理合成了三维铋矿Bi2O2CO3纳米粒子(BSC NPs)。反应温度和NaOH浓度对所获得的BSC NP的物理和光催化性能有重要影响。分别用X射线衍射、扫描电子显微镜、能谱仪、N2吸附/脱附等温线和紫外-可见光谱对所得催化剂的晶体结构、形貌、化学组成、比表面积和光响应进行了表征。此外,以罗丹明6G为模型反应,评价了BSC纳米粒子的光催化活性。结果表明,水热反应温度和NaOH浓度对相结构和紫外-可见光响应没有明显影响;而形貌、BET表面积和光活性受水热反应温度和NaOH浓度的影响。
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引用次数: 5
Reappraising 1907 Einstein’s Model of Specific Heat 重新评价1907年爱因斯坦的比热模型
Pub Date : 2016-10-25 DOI: 10.4236/OJPC.2016.64011
S. Tosto
This article emphasizes that the Einstein and Debye models of specific heats of solids are correlated more tightly than currently acknowledged. This correlation is evidenced without need of additional hypotheses on the early Einstein model. The results are also extensible to the case of a system of fermions; as an example, the specific heat of the electron sea in metals is inferred in the frame of the proposed approach only.
这篇文章强调,爱因斯坦和德拜模型的固体比热比目前公认的更紧密相关。这种相关性不需要对早期爱因斯坦模型进行额外的假设就可以得到证明。结果也可以推广到费米子系统的情况;作为一个例子,金属中电子海的比热仅在所提出的方法框架内推断出来。
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引用次数: 3
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